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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 imaging.

    PubMed

    Daniel, Gregory B

    2009-07-01

    Medical imaging is rapidly moving toward a digital-based image system. An understanding of the principles of digital imaging is necessary to evaluate features of imaging systems and can play an important role in purchasing decisions.

  3. Digital Imaging.

    ERIC Educational Resources Information Center

    Howell, Les

    1996-01-01

    Defines a digital photograph as a numerical record of light electronically measured and recorded by a computer's scanner. States that most personal computers cannot do digital photography successfully and that digital pictures can be hard to manage and present a storage problem. Finds that, once the school has the hardware/software, picture…

  4. 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 …

  5. 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…

  6. Digital Imaging

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Digital Imaging is the computer processed numerical representation of physical images. Enhancement of images results in easier interpretation. Quantitative digital image analysis by Perceptive Scientific Instruments, locates objects within an image and measures them to extract quantitative information. Applications are CAT scanners, radiography, microscopy in medicine as well as various industrial and manufacturing uses. The PSICOM 327 performs all digital image analysis functions. It is based on Jet Propulsion Laboratory technology, is accurate and cost efficient.

  7. 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.

  8. Digital printing

    NASA Astrophysics Data System (ADS)

    Sobotka, Werner K.

    1997-02-01

    Digital printing is described as a tool to replace conventional printing machines completely. Still this goal was not reached until now with any of the digital printing technologies to be described in the paper. Productivity and costs are still the main parameters and are not really solved until now. Quality in digital printing is no problem anymore. Definition of digital printing is to transfer digital datas directly on the paper surface. This step can be carried out directly or with the use of an intermediate image carrier. Keywords in digital printing are: computer- to-press; erasable image carrier; image carrier with memory. Digital printing is also the logical development of the new digital area as it is pointed out in Nicholas Negropotes book 'Being Digital' and also the answer to networking and Internet technologies. Creating images text and color in one country and publishing the datas in another country or continent is the main advantage. Printing on demand another big advantage and last but not least personalization the last big advantage. Costs and being able to coop with this new world of prepress technology is the biggest disadvantage. Therefore the very optimistic growth rates for the next few years are really nonexistent. The development of complete new markets is too slow and the replacing of old markets is too small.

  9. Digitizing Preservation.

    ERIC Educational Resources Information Center

    Conway, Paul

    1994-01-01

    Discussion of digital imaging technology focuses on its potential use for preservation of library materials. Topics addressed include converting microfilm to digital; the high cost of conversion from paper or microfilm; quality; indexing; database management issues; incompatibility among imaging systems; longevity; cooperative pilot projects; and…

  10. 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…

  11. 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.

  12. Digital Ethics/Going Digital.

    ERIC Educational Resources Information Center

    Wilson, Bradley

    1996-01-01

    Finds that the recent National Press Photographers Association code of ethics can serve as a model for any photography staff. Discusses how digital imaging is becoming commonplace in classrooms, due to decreasing costs and easier software. Explains digital terminology. Concludes that time saved in the darkroom and at the printer is now spent on…

  13. 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

  14. 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;…

  15. 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.

  16. Digital karyotyping.

    PubMed

    Wang, Tian-Li; Maierhofer, Christine; Speicher, Michael R; Lengauer, Christoph; Vogelstein, Bert; Kinzler, Kenneth W; Velculescu, Victor E

    2002-12-10

    Alterations in the genetic content of a cell are the underlying cause of many human diseases, including cancers. We have developed a method, called digital karyotyping, that provides quantitative analysis of DNA copy number at high resolution. This approach involves the isolation and enumeration of short sequence tags from specific genomic loci. Analysis of human cancer cells by using this method identified gross chromosomal changes as well as amplifications and deletions, including regions not previously known to be altered. Foreign DNA sequences not present in the normal human genome could also be readily identified. Digital karyotyping provides a broadly applicable means for systematic detection of DNA copy number changes on a genomic scale.

  17. 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.

  18. 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.

  19. 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…

  20. 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…

  1. [Digital radiography].

    PubMed

    Haendle, J

    1983-03-01

    Digital radiography is a generally accepted term comprising all x-ray image systems producing a projected image which resembles the conventional x-ray film image, and which are linked to any type of digital image processing. Fundamental criteria of differentiation are based on the production and detection method of the x-ray image. Various systems are employed, viz. the single-detector, line-detector or fanbeam detector and the area-beam or area-detector image converters, which differ from one another mainly in the manner of conversion of the radiation produced by the x-ray tube. The article also deals with the pros and cons of the various principles, the multitude of systems employed, and the varying frequency of their use in x-ray diagnosis work.

  2. Digital Earth

    NASA Astrophysics Data System (ADS)

    de La Beaujardiere, J.

    2001-05-01

    Digital Earth (DE) seeks to make geospatial information broadly and easily available. Vast amounts of natural and cultural information are gathered about the Earth, but it is often difficult to find needed data, to share knowledge across disciplines, and to combine information from several sources. DE defines a framework for interoperability by selecting relevant open standards from the information technology community. These standards specify the technical means by which publishers can provide or sell their data, and by which client applications can find and access data in an automated fashion. The standardized DE framework enables many types of clients--from web browsers to museum kiosks to research-grade virtual environments--to use a common geospatial information infrastructure. Digital Earth can benefit Earth system education in general, and DLESE in particular, in several ways. First, educators, students and creators of instructional material will benefit from standardized access to georeferenced data. Secondly, educational lesson plans that focus on a region or aspect of the Earth can themselves be considered geospatial information resources that could be cataloged and retrieved through DE. Finally, general public knowledge about our planet will by increased by Digital Earth.

  3. 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…

  4. 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.

  5. 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.

  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 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.

  8. 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.

  9. Digital communications: Microwave applications

    NASA Astrophysics Data System (ADS)

    Feher, K.

    Transmission concepts and techniques of digital systems are presented; and practical state-of-the-art implementation of digital communications systems by line-of-sight microwaves is described. Particular consideration is given to statistical methods in digital transmission systems analysis, digital modulation methods, microwave amplifiers, system gain, m-ary and QAM microwave systems, correlative techniques and applications to digital radio systems, hybrid systems, digital microwave systems design, diversity and protection switching techniques, measurement techniques, and research and development trends and unsolved problems.

  10. Digital rectal exam

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007069.htm Digital rectal exam To use the sharing features on this page, please enable JavaScript. A digital rectal exam is an examination of the lower ...

  11. Digital flight control research

    NASA Technical Reports Server (NTRS)

    Potter, J. E.; Stern, R. G.; Smith, T. B.; Sinha, P.

    1974-01-01

    The results of studies which were undertaken to contribute to the design of digital flight control systems, particularly for transport aircraft are presented. In addition to the overall design considerations for a digital flight control system, the following topics are discussed in detail: (1) aircraft attitude reference system design, (2) the digital computer configuration, (3) the design of a typical digital autopilot for transport aircraft, and (4) a hybrid flight simulator.

  12. TELEMETRY EQUIPMENT WITH DIGITAL READING,

    DTIC Science & Technology

    Contents: Basic peculiarities of telemetry equipment with digital reading ; Elements of pulse technology applied in telemetry equipment with digital... reading ; Digital reading systems; Telemetry systems with digital reading . (Author)

  13. 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…

  14. 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

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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.

  20. 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…

  1. 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.

  2. Digital Monopulse Receivers for Phase Modulated Signals

    DTIC Science & Technology

    2005-04-14

    comunicaciones ación... e Madrid s/n...θ1k Σ+j∆ ∆ digital Σ digital Signal formation ∆ digit Σ digitdigit Σ digitRCHITECTURES BASED ON AMPLITUDE MEASUREMENT e architectures perform the

  3. 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

  4. 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.

  5. Saving Amputated Digits

    PubMed Central

    Frykman, Gary K.; Wood, Virchel E.

    1974-01-01

    Since the advent of microsurgery in the 1960's it has become possible to sucessfully repair vessels as small as 0.5 mm in diameter, which makes the replantation of totally severed digits possible. Some centers have reported 50 to 60 percent survival of completely severed digits and up to 100 percent survival of amputated hands and of partially amputed but otherwise non-viable digits that were reattached. In view of this success, severed members should be considered as potentially replantable. The recommended indications for replantation are: (1) multiple digital amputations at or proximal to the proximal interphalangeal joint; (2) amputation of the thumb; (3) amputation of the wrist or hand; (4) partially attached digits that are non-viable without reattachment. The surviving replanted digits give functional improvement to the hand and prove cosmetically acceptable. ImagesFigure 1.Figure 2. PMID:4608643

  6. Digital Natives and Digital Divide: Analysing Perspective for Emerging Pedagogy

    ERIC Educational Resources Information Center

    Onye, Uriel U.; Du, Yunfei

    2016-01-01

    This paper addresses the concepts of digital natives and digital divide from the perspective of the digital outsiders (part of digital natives). It takes a critical look at the implications of available ICT in both developed and underdeveloped countries in the fight against digital divide. The major contribution to literature is by drawing…

  7. 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).

  8. 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

  9. 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)

  10. 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.

  11. Digital Electronic Still Camera

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D.; Yeates, Herbert D.

    1993-01-01

    Digital electronic still camera part of electronic recording, processing, tansmitting, and displaying system. Removable hard-disk drive in camera serves as digital electronic equivalent of photographic film. Images viewed, analyzed, or transmitted quickly. Camera takes images of nearly photographic quality and stores them in digital form. Portable, hand-held, battery-powered unit designed for scientific use. Camera used in conjunction with playback unit also serving as transmitting unit if images sent to remote station. Remote station equipped to store, process, and display images. Digital image data encoded with error-correcting code at playback/transmitting unit for error-free transmission to remote station.

  12. 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.

  13. 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.

  14. Digital ureteroscopes: technology update

    PubMed Central

    Gridley, Chad M; Knudsen, Bodo E

    2017-01-01

    The field of ureteroscopy has undergone a continual evolution since the first ureteroscopes were introduced. Over the past 10 years, we have entered into the digital era of ureteroscopy with both semirigid and flexible options becoming available. The following review looks at the benefits and drawbacks of digital flexible ureteroscopes as well as the current commercially available options. PMID:28203551

  15. 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…

  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. 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…

  18. 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…

  19. 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.…

  20. 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.

  1. 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.

  2. Improved digital thermometer design.

    PubMed

    Swift, C S

    1981-01-01

    A simple digital thermometer design using a self-contained 3 1/2 digit LCD meter module is presented. The Celsius-reading (Centigrade) thermometer is powered by a single 9-V battery, has very low power drain, and uses an inexpensive NPN silicon transistor for the temperature sensor. A short bibliography on temperature measurement instrumentation is included.

  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. 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…

  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. Digital Libraries: An Overview.

    ERIC Educational Resources Information Center

    Schwartz, Candy

    2000-01-01

    Provides an overview of the basic components of a digital library. Highlights include library collections; metadata; services, including information seeking and retrieval, reference query fulfillment, and user training; user interaction with digital libraries, including searching, browsing, and navigation; economic support; maintenance;…

  7. Digital Readiness Gaps

    ERIC Educational Resources Information Center

    Horrigan, John B.

    2016-01-01

    For many years concerns about "digital divides" centered primarily on whether people had "access" to digital technologies. Now, those worried about these issues also focus on the degree to which people succeed or struggle when they use technology to try to navigate their environments, solve problems, and make decisions. This…

  8. 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…

  9. 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…

  10. Digitized synchronous demodulator

    NASA Technical Reports Server (NTRS)

    Woodhouse, Christopher E. (Inventor)

    1990-01-01

    A digitized synchronous demodulator is constructed entirely of digital components including timing logic, an accumulator, and means to digitally filter the digital output signal. Indirectly, it accepts, at its input, periodic analog signals which are converted to digital signals by traditional analog-to-digital conversion techniques. Broadly, the input digital signals are summed to one of two registers within an accumulator, based on the phase of the input signal and medicated by timing logic. At the end of a predetermined number of cycles of the inputted periodic signals, the contents of the register that accumulated samples from the negative half cycle is subtracted from the accumulated samples from the positive half cycle. The resulting difference is an accurate measurement of the narrow band amplitude of the periodic input signal during the measurement period. This measurement will not include error sources encountered in prior art synchronous demodulators using analog techniques such as offsets, charge injection errors, temperature drift, switching transients, settling time, analog to digital converter missing code, and linearity errors.

  11. 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…

  12. 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…

  13. 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.

  14. 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,…

  15. 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…

  16. 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,…

  17. 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…

  18. 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…

  19. 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.

  20. Those Nifty Digital Cameras!

    ERIC Educational Resources Information Center

    Ekhaml, Leticia

    1996-01-01

    Describes digital photography--an electronic imaging technology that merges computer capabilities with traditional photography--and its uses in education. Discusses how a filmless camera works, types of filmless cameras, advantages and disadvantages, and educational applications of the consumer digital cameras. (AEF)

  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. 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…

  3. 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…

  4. 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.

  5. 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.

  6. Predictive dynamic digital holography

    NASA Astrophysics Data System (ADS)

    Sulaiman, Sennan; Gibson, Steve; Spencer, Mark

    2016-09-01

    Digital holography has received recent attention for many imaging and sensing applications, including imaging through turbulent and turbid media, adaptive optics, three dimensional projective display technology and optical tweezing. A significant obstacle for digital holography in real-time applications, such as wavefront sensing for high energy laser systems and high speed imaging for target tracking, is the fact that digital holography is computationally intensive; it requires iterative virtual wavefront propagation and hill-climbing to optimize some sharpness criteria. This paper demonstrates real-time methods for digital holography based on approaches developed recently at UCLA for optimal and adaptive identification, prediction, and control of optical wavefronts. The methods presented integrate minimum variance wavefront prediction into digital holography schemes to short-circuit the computationally intensive algorithms for iterative propagation of virtual wavefronts and hill climbing for sharpness optimization.

  7. 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…

  8. 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…

  9. Digital imaging in pathology.

    PubMed

    Park, Seung; Pantanowitz, Liron; Parwani, Anil Vasdev

    2012-12-01

    Advances in computing speed and power have made a pure digital work flow for pathology. New technologies such as whole slide imaging (WSI), multispectral image analysis, and algorithmic image searching seem poised to fundamentally change the way in which pathology is practiced. This article provides the practicing pathologist with a primer on digital imaging. Building on this primer, the current state of the art concerning digital imaging in pathology is described. Emphasis is placed on WSI and its ramifications, showing how it is useful in both anatomic (histology, cytopathology) and clinical (hematopathology) pathology. Future trends are also extrapolated.

  10. Digital sonar system

    DOEpatents

    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.

  11. Digital sonar system

    DOEpatents

    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.

  12. Fast transient digitizer

    DOEpatents

    Villa, Francesco

    1982-01-01

    Method and apparatus 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.

  13. 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…

  14. 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…

  15. 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.

  16. Digital ac monitor

    DOEpatents

    Hart, G.W.; Kern, E.C. Jr.

    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. 24 figs.

  17. Digital Electronics for Everyone.

    ERIC Educational Resources Information Center

    Kasper, Joseph E.; Feller, Steven A.

    1982-01-01

    A digital electronics course taught on four successive Saturdays is described. Includes comments on course goals, text materials, and hardware. A table summarizing class and laboratory parts of the sessions is also provided. (JN)

  18. The Coevolution of Digital Ecosystems

    ERIC Educational Resources Information Center

    SungYong, Um

    2016-01-01

    Digital ecosystems are one of the most important strategic issues in the current digital economy. Digital ecosystems are dynamic and generative. They evolve as new firms join and as heterogeneous systems are integrated into other systems. These features digital ecosystems determine economic and technological success in the competition among…

  19. 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.

  20. 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.

  1. Digit ratio in birds.

    PubMed

    Lombardo, Michael P; Thorpe, Patrick A; Brown, Barbara M; Sian, Katie

    2008-12-01

    The Homeobox (Hox) genes direct the development of tetrapod digits. The expression of Hox genes may be influenced by endogenous sex steroids during development. Manning (Digit ratio. New Brunswick, NJ: Rutgers University Press, 2002) predicted that the ratio between the lengths of digits 2 (2D) and 4 (4D) should be sexually dimorphic because prenatal exposure to estrogens and androgens positively influence the lengths of 2D and 4D, respectively. We measured digits and other morphological traits of birds from three orders (Passeriformes, house sparrow, Passer domesticus; tree swallow, Tachycineta bicolor; Pscittaciformes, budgerigar, Melopsittacus undulates; Galliformes, chicken, Gallus domesticus) to test this prediction. None were sexually dimorphic for 2D:4D and there were no associations between 2D:4D and other sexually dimorphic traits. When we pooled data from all four species after we averaged right and left side digits from each individual and z-transformed the resulting digit ratios, we found that males had significantly larger 2D:4D than did females. Tetrapods appear to be sexually dimorphic for 2D:4D with 2D:4D larger in males as in some birds and reptiles and 2D:4D smaller in males as in some mammals. The differences between the reptile and mammal lineages in the directionality of 2D:4D may be related to the differences between them in chromosomal sex determination. We suggest that (a) natural selection for a perching foot in the first birds may have overridden the effects of hormones on the development of digit ratio in this group of vertebrates and (b) caution be used in making inferences about prenatal exposure to hormones and digit ratio in birds.

  2. 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.

  3. 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

  4. Digital Elevation Models

    USGS Publications Warehouse

    ,

    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.

  5. Comparison Of Digital Radiographic Units

    NASA Astrophysics Data System (ADS)

    Wang, Yen

    1986-06-01

    A total PACS will be inevitable for radiology practice within several years. To achieve a total PACS for radiology, a satisfactory digital radiographic unit is required, because approximately 65% of digital data for PACS comes from digital radiographs. There are several possibilities for producing digital radiographs, and 3 - 4 companies have been marketing digital radiographic devices. Some data regarding the digital radiographic units on the market are compared. It will aid in assessing the current status and availability of this aspect of development, as well as providing a summary of further development of digital radiographic technology.

  6. 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…

  7. 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

  8. 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.

  9. Genetics of digital osteoarthritis.

    PubMed

    Michou, Laëtitia

    2011-07-01

    Genetic factors contribute to the development of digital osteoarthritis, whose heritability has been estimated at 48 to 65%. Among the manifestations of digital osteoarthritis, only Heberden's nodes are transmitted by Mendelian inheritance, as a dominant trait in women and a recessive trait in men. The other forms of digital osteoarthritis are multifactorial, with a major gene and a residual multifactorial component that probably interacts with environmental factors. Hindrances to molecular studies include the absence to date of a universally accepted definition of the phenotype and the late onset of the manifestations. Genetic association studies of selected class I and II HLA genes produced conflicting results. The T303M polymorphism of the MATN3 gene, which was initially described as associated with hand osteoarthritis, may be more closely linked to trapeziometacarpal osteoarthritis than to digital osteoarthritis. Genome-wide scans have identified numerous loci linked to digital osteoarthritis. Replication has been achieved for some of these loci, most notably those located at 2p, 2q, 3p, 4q, and 7p. A recently published genome-wide association study showed that an A2BP1 gene polymorphism was significantly associated with hand osteoarthritis. Many candidate-gene studies found associations with AGC1, ASPN, ENPP1, HFE, KL, VDR, IL-1 cluster, and IL-6, although the results were not consistently reproducible. In one study, women with hand osteoarthritis had significant telomere shortening. Telomere shortening has also been reported in other age-related conditions.

  10. 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.

  11. 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

  12. TOCM digital color photography

    NASA Astrophysics Data System (ADS)

    Zhang, Baoying; Mu, Guoguang; Fang, Zhiliang; Li, Zhengqun; Fang, Hui; Yang, Yong

    2009-11-01

    In this paper, total optical color modulator (TOCM) digital color photography is presented. TOCM has the character of multi-wave superposed in spatial domain and separated in frequency domain. If TOCM is close-contacted with the image plane of a black-and-white (B&W) CCD, the encoding B&W CCD is formed. Image from the encoding B&W CCD are digital encoded by the TOCM. The decoded color image can be obtained by computer program. The program includes four main steps. The first step is Fourier transforming of the encoded image. The second step is filtering the spectra of the first and zero order in frequency domain. The third is inverse Fourier transforming of the filtered spectra. The last is melting the image with zero order. Then the digital color image will be shown on the display of the computer. The experiment proves that this technique is feasible. The principle of encoding color information in B&W image can be applied to color-blind sensors to get digital color image. Furthermore, it can be applied to digital multi-spectra color photography.

  13. Digital magnetic temperature transducer.

    NASA Technical Reports Server (NTRS)

    Tchernev, D. I.; Collier, T. E.

    1971-01-01

    A new digital magnetic temperature transducer is reported. The device utilizes the discontinuous behavior of the initial permeability with temperature at the Curie temperature of some magnetic materials. Since the Curie temperature is determined by the chemical and crystallographic composition of the particular material only, the transducer requires no calibration and has extremely high stability and reproducibility with time. The output of the transducer is inherently digital and, therefore, is directly compatible with the digital information processing and control without A/D conversion. The temperature-sensing portion of the transducer consists only of magnetic cores and wire and, therefore, has extremely high reliability, is shock and radiation insensitive, small, and virtually indestructible.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Secure medical digital libraries.

    PubMed

    Papadakis, I; Chrissikopoulos, V; Polemi, D

    2001-12-01

    In this paper, a secure medical digital library is presented. It is based on the CORBA specifications for distributed systems. The described approach relies on a three-tier architecture. Interaction between the medical digital library and its users is achieved through a Web server. The choice of employing Web technology for the dissemination of medical data has many advantages compared to older approaches, but also poses extra requirements that need to be fulfilled. Thus, special attention is paid to the distinguished nature of such medical data, whose integrity and confidentiality should be preserved at all costs. This is achieved through the employment of Trusted Third Parties (TTP) technology for the support of the required security services. Additionally, the proposed digital library employs smartcards for the management of the various security tokens that are used from the above services.

  20. 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.

  1. 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.

  2. Sloan Digital Sky Survey

    SciTech Connect

    Kent, S.M.

    1993-11-01

    The Solan Digital Sky Survey is a project which will produce a detailed digital phometric map of half the northern sky to about 23 magnitude using a special purpose wide field telescope of 2.5 meter aperture. This map will be used to select about a million galaxies and 100,000 quasars, for which high resolution spectra will be obtained using the same telescope. A catalog will be produced of all the detected objects, about 100 million galaxies and a similar number of stars, and a million quasar candidates.

  3. Energy Efficient Digital Networks

    SciTech Connect

    Lanzisera, Steven; Brown, Richard

    2013-01-01

    Digital networks are the foundation of the information services, and play an expanding and indispensable role in our lives, via the Internet, email, mobile phones, etc. However, these networks consume energy, both through the direct energy use of the network interfaces and equipment that comprise the network, and in the effect they have on the operating patterns of devices connected to the network. The purpose of this research was to investigate a variety of technology and policy issues related to the energy use caused by digital networks, and to further develop several energy-efficiency technologies targeted at networks.

  4. Digital DICOM in Dentistry.

    PubMed

    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.

  5. Digital camera simulation.

    PubMed

    Farrell, Joyce E; Catrysse, Peter B; Wandell, Brian A

    2012-02-01

    We describe a simulation of the complete image processing pipeline of a digital camera, beginning with a radiometric description of the scene captured by the camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual digital camera components on system performance and image quality. This computational approach can be helpful for both camera design and image quality assessment.

  6. 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.

  7. 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

  8. Digital Downsides: Exploring University Students' Negative Engagements with Digital Technology

    ERIC Educational Resources Information Center

    Selwyn, Neil

    2016-01-01

    Digital technologies are now an integral feature of university study. As such, academic research has tended to concentrate on the potential of digital technologies to support, extend and even "enhance" student learning. This paper, in contrast, explores the rather more messy realities of students' engagements with digital technology. In…

  9. 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…

  10. 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…

  11. 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.

  12. Traveling digital counters for micrometers

    NASA Technical Reports Server (NTRS)

    Haley, C. T.; Moore, J. M.

    1973-01-01

    Five digit micrometer readings are made directly and quickly with no loss of precision. It is virtually impossible for micrometer to be misread. Digitized micrometer can also be used for reptitive measurements.

  13. 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 ).

  14. Digital Reference Service.

    ERIC Educational Resources Information Center

    Mon, Lorri

    2000-01-01

    Discusses the increasing demand for digital reference services from government Web sites via email, and describes a partnership between the Government Printing Office and the federal depository library at the University of Illinois at Chicago to create electronic access to the Department of State Foreign Affairs Network (DOSFAN). (Author/LRW)

  15. 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…

  16. 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.

  17. 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…

  18. 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.

  19. The digital curriculum vitae.

    PubMed

    Galdino, Greg M; Gotway, Michael

    2005-02-01

    The curriculum vitae (CV) has been the traditional method for radiologists to illustrate their accomplishments in the field of medicine. Despite its presence in medicine as a standard, widely accepted means to describe one's professional career and its use for decades as an accomplice to most applications and interviews, there is relatively little written in the medical literature regarding the CV. Misrepresentation on medical students', residents', and fellows' applications has been reported. Using digital technology, CVs have the potential to be much more than printed words on paper and offers a solution to misrepresentation. Digital CVs may incorporate full-length articles, graphics, presentations, clinical images, and video. Common formats for digital CVs include CD-ROMs or DVD-ROMs containing articles (in Adobe Portable Document Format) and presentations (in Microsoft PowerPoint format) accompanying printed CVs, word processing documents with hyperlinks to articles and presentations either locally (on CD-ROMs or DVD-ROMs) or remotely (via the Internet), or hypertext markup language documents. Digital CVs afford the ability to provide more information that is readily accessible to those receiving and reviewing them. Articles, presentations, videos, images, and Internet links can be illustrated using standard file formats commonly available to all radiologists. They can be easily updated and distributed on an inexpensive media, such as a CD-ROM or DVD-ROM. With the availability of electronic articles, presentations, and information via the Internet, traditional paper CVs may soon be superseded by their electronic successors.

  20. Light microscopy digital imaging.

    PubMed

    Joubert, James; Sharma, Deepak

    2011-10-01

    This unit presents an overview of digital imaging hardware used in light microscopy. CMOS, CCD, and EMCCDs are the primary sensors used. The strengths and weaknesses of each define the primary applications for these sensors. Sensor architecture and formats are also reviewed. Color camera design strategies and sensor window cleaning are also described in the unit.

  1. 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"…

  2. 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.

  3. Are Languages Digital Codes?

    ERIC Educational Resources Information Center

    Love, Nigel

    2007-01-01

    Language use is commonly understood to involve digital signalling, which imposes certain constraints and restrictions on linguistic communication. Two papers by Ross [Ross, D., 2004. "Metalinguistic signalling for coordination amongst social agents." "Language Sciences" 26, 621-642; Ross, D., this issue. "'H. sapiens' as ecologically special: what…

  4. Interfacing the Digital.

    ERIC Educational Resources Information Center

    Dietz, Steve

    In the last 5 years, there has been at times heated debate not only about how best to present digital and specifically networked art in an institutional context but also whether to do so at all. Not all of the discussion revolves around issues of physical interfaces to such works, but their onsite presentation is a critical concern for both…

  5. 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…

  6. Digital transversal filter architecture

    NASA Astrophysics Data System (ADS)

    Greenberger, A. J.

    1985-01-01

    A fast and efficient architecture is described for the realization of a pipelined, fully parallel digital transversal filter in VLSI. The order of summation is changed such that no explicit multiplication is seen, gated accumulators are used, and the coefficients are circulated. Estimates for the number of transistors needed for a CMOS implementation are given.

  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. Middleware for Digital Libraries.

    ERIC Educational Resources Information Center

    Bacon, Jean; Hayton, Richard; Moody, Ken

    1998-01-01

    Describes a security architecture, Oasis, which runs on a middleware platform extended for asynchronous operation; shows how the interoperation of independently developed services may be supported under the Oasis architecture. Uses the provision of digital academic library services as an example. (Author/AEF)

  9. 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…

  10. 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.…

  11. 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…

  12. 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.

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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)

  18. 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…

  19. 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.

  20. 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.

  1. Optical watthour meter digitizer

    SciTech Connect

    Andrews, W.H.

    1980-10-01

    As concern about energy conservation and energy-use efficiency increases, a simple and inexpensive instrument that would provide accurate, reliable and high-resolution data on electrical energy usage should find widespread application in research and industrial facilities. An instrument that would also provide one or more outputs compatible with a wide range of digital data acquisition systems would be especially appropriate, since the use of automatic data logging equipment is now common, even in small-scale and low-budget operations. An optical watthour meter digitizer was developed which meets these criteria. Based on the induction-type watthour meter, the digitizer provides an output pulse for a fixed amount of energy use. The digitizer senses the motion of the rotor disc of the meter by optically detecting passage of a nonreflective area painted on the underside of the disc. The passage of such area initiates a logic-compatible output pulse that can be used to measure power or energy usage in a variety of ways. The accuracy of the measurement is determined by the watthour meter. The resolution of the measurement is determined by the K/sub h/ constant (in watthours per revolution) of the meter and the number of equally spaced targets painted on the disc. The resolution of this device can be as small as a fraction of a watthour; the resolution of the manually read register on a watthour meter is typically a fraction of a kilowatthour. Several digitizers were fabricated, bench-tested, and installed in the field for long-term performance testing. All are performing satisfactorily.

  2. Dynamic Digital Libraries for Children.

    ERIC Educational Resources Information Center

    Theng, Yin Leng; Mohd-Nasir, Norliza; Buchanan, George; Fields, Bob; Thimbleby, Harold; Cassidy, Noel

    The design of systems, including digital libraries, is often inspired by what technology makes possible. In user-centered design, design emphasizes users, their tasks and needs. The majority of current digital libraries are not designed for children. For digital libraries to be popular with children, they need to be fun and easy-to-use. This paper…

  3. 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…

  4. 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.

  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. An Overview of Digital Video.

    ERIC Educational Resources Information Center

    Barron, Ann E.

    1995-01-01

    Factors driving the shift from analog to digital video storage and retrieval are discussed, including improved compression techniques, reduced hardware costs, and increased network demands. Characteristics of digital video and various compression procedures are described. Applications and guidelines for use of digital video in higher education…

  7. 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…

  8. Digital Storytelling in Higher Education

    ERIC Educational Resources Information Center

    McLellan, Hilary

    2007-01-01

    Digital storytelling is a promising instructional strategy as well as an emerging field of study in higher education. Courses on digital storytelling are offered in communications and creative writing programs at a number of universities. However, the potential for digital storytelling extends far beyond the fields of communication and media…

  9. 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…

  10. 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.

  11. 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.…

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Digital image storage.

    PubMed

    Wallack, Seth

    2008-01-01

    Digital image archival requires less physical storage space, allows for rapid storage and retrieval and avoids loss in image quality over time or with image duplication compared with film storage. Because medical imaging data are critically important and, by law, must be stored in a safe, accessible manner, it is imperative not to have one computer error destroy all copies of the image data. Several options for image storage media are available including magnetic tape, optical media, spinning disks and solid state. Other considerations include on-site vs. off-site storage, redundancy, on-line vs. off-line storage, and removable storage media for disaster recovery. The different storage media can be used in different configurations to provide sufficient protection of digital data. Choose a storage system that will keep your data safe from unauthorized access, hardware failure, and clinic disasters.

  18. Digitized Heat Transfer

    NASA Astrophysics Data System (ADS)

    Mohseni, Kamran; Young, Patrick

    2007-11-01

    This presentation presents theoretical and numerical results describing digitized heat transfer (DHT), an active thermal management technique for high-power electronics and integrated micro systems. In digitized heat transfer discrete droplets are employed. The internal flow inside a discrete droplet is dominated by internal circulation imposed by the boundaries. This internal circulation imposes a new timescale for recirculating cold liquid from the middle of the droplet to the boundary. This internal circulation produces periodic oscillation in the overall convective heat transfer rate. Numerical simulations are presented for heat transfer in the droplet for both constant temperature and flux boundary conditions. The effectiveness of DHT for managing both localized temperature spikes and steady state cooling is demonstrated, identifying key parameters for optimization of the DHT method.

  19. 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.

  20. 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.

  1. 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.

  2. Digital Systems Technical Analysis.

    DTIC Science & Technology

    1982-10-01

    airline is based on both historical data and predictions related to the most effective and economic means of avoiding reliability deteriora- tion. Once...70405 55? DIGITAL SYSTE MS TECHNICAL NLYSIS(U) ARINC RESEARCH- /i I CORP ANNAPOLIS MD L H HOGLE ET AL. OCT 82 LA 1469-01-1-2884 DOT/FRR/CT-S2/129...Performing Organization Name and Address 10. Work Unit N. (TRAIS) ARINC Research Corporation 11. Contract or Grant N. 2551 Riva Road Annapolis

  3. 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.

  4. Principles of digital imaging.

    PubMed

    van der Stelt, P F

    2000-04-01

    Electronic sensors in diagnostic radiology are gradually replacing radiographic film. The advantages of this new technology include a lower radiation dose to the patient, an almost instantaneous availability of images without the need for chemical film processing, and the possibility of image enhancement and computer-aided feature extraction. Digital radiography is a promising technology, opening the door to new diagnostic procedures not available with traditional film-based imaging.

  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 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.

  7. 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

  8. Effectiveness of Digital Pulse Processing Using a Slow Waveform Digitizer

    NASA Astrophysics Data System (ADS)

    Anthony, Adam; Ahmed, Mohammad; Sikora, Mark

    2016-09-01

    Using a waveform digitizer, one can replace nearly all of the analog electronics typically involved in processing pulses from a detector by directly digitizing the signal and processing it using digital algorithms. Algorithms for timing filter amplification, constant fraction discrimination, trapezoidal pulse shaping, peak sensing with pileup rejection, and charge integration were developed and implemented. The algorithms and a digitizer with a sampling rate of 62.5 MS/sec were used to calculate the energy and timing resolution of a various scintillation and solid state detectors. These resolutions are compared against both a traditional charge to digital (QDC), and the analog to digital (ADC) data acquisition setup in use at the High Intensity Gamma Source at Duke University. Preliminary results are presented.

  9. Magnetic digital microfluidics - a review.

    PubMed

    Zhang, Yi; Nguyen, Nam-Trung

    2017-03-14

    A digital microfluidic platform manipulates droplets on an open surface. Magnetic digital microfluidics utilizes magnetic forces for actuation and offers unique advantages compared to other digital microfluidic platforms. First, the magnetic particles used in magnetic digital microfluidics have multiple functions. In addition to serving as actuators, they also provide a functional solid substrate for molecule binding, which enables a wide range of applications in molecular diagnostics and immunodiagnostics. Second, magnetic digital microfluidics can be manually operated in a "power-free" manner, which allows for operation in low-resource environments for point-of-care diagnostics where even batteries are considered a luxury item. This review covers research areas related to magnetic digital microfluidics. This paper first summarizes the current development of magnetic digital microfluidics. Various methods of droplet manipulation using magnetic forces are discussed, ranging from conventional magnetic particle-based actuation to the recent development of ferrofluids and magnetic liquid marbles. This paper also discusses several new approaches that use magnetically controlled flexible substrates for droplet manipulation. In addition, we emphasize applications of magnetic digital microfluidics in biosensing and medical diagnostics, and identify the current limitations of magnetic digital microfluidics. We provide a perspective on possible solutions to close these gaps. Finally, the paper discusses the future improvement of magnetic digital microfluidics to explore potential new research directions.

  10. Acquisition hardware for digital imaging.

    PubMed

    Widmer, William R

    2008-01-01

    Use of digital radiography is growing rapidly in veterinary medicine. Two basic digital imaging systems are available, computed radiography (CR) and direct digital radiography (DDR). Computed radiographic detectors use a two-step process for image capture and processing. Image capture is by X-ray sensitive phosphors in the image plate. The image plate reader transforms the latent phosphor image to light photons that are converted to an analog electrical signal. An analog to digital converter is used to digitize the electrical signal before computer analysis. Direct digital detectors provide digital data by direct readout after image capture--a reader unnecessary. Types of DDR detectors are flat panel detectors and charge coupled device (CCD) detectors. Flat panel detectors are composed of layers of semiconductors for image capture with transistor and microscopic circuitry embedded in a pixel array. Direct converting flat panel detectors convert incident X-rays directly into electrical charges. Indirect detectors convert X-rays to visible light, then to electrical charges. All flat panel detectors send a digitized electrical signal to a computer using a direct link. Charge coupled device detectors have a small chip similar to those used in digital cameras. A scintillator first converts X-rays to a light signal that is minified by an optical system before reaching the chip. The chip sends a digital signal directly to a computer. Both CR and DDR provide quality diagnostic images. CR is a mature technology while DDR is an emerging technology.

  11. Digital Radiography: A Technology Overview

    NASA Astrophysics Data System (ADS)

    Arnold, Ben A.

    1982-12-01

    Digital radiography, a term hardly recognized two years ago, has grown to become the talk of the radiology community and the excitement of many commercial companies. M2st of this attention has been directed toward digital subtraction intravenous angiography), although during this same time period, a variety of digital radiography apparatus and image processing techniques have been under development. In November of 1980 at the RSNA Conference in Chicago, three commercial digital angiography systems were announced by Philips, Technicare and ADAC Corporations. During this same time period, the University of Arizona was discussing the concept of a photo electronic radiology department2, the University of Pittsburg and Stanford University were investigating line scan radiography3,4 and approximately five laboratories were carrying out clinical IV angiography with digital video systems.5-9 These developments followed basic research programs in digital electronic and computerized imaging at various locations around the world. 10-18 In the spring of 1981 we attempted to review the state of digital radiography, focusing on the various detector systems and image acquisition approaches.19 Since that time, rapid advancements in digital radiography have occurred. A major conference was held on digital radiography at Stanford UniversityzO, a new area detector system for digital radiography was announced by Fuji Film Corporation, clinical testing began on the Picker line scan digital chest unit21, and improvements were made in selenium detectors for digital radiography. Several additional companies announced digital video angiography systems, bringing the total now to approximately 15 companies worldwide. Digital video subtraction angiography is now well established as an important clinical diagnostic procedure and a variety of improvements and extensions of digital angiography systems are now ongoing. Digital acquisition and storage systems are increasing in both speed and

  12. A veterinary digital anatomical database.

    PubMed

    Snell, J R; Green, R; Stott, G; Van Baerle, S

    1991-01-01

    This paper describes the Veterinary Digital Anatomical Database Project. The purpose of the project is to investigate the construction and use of digitally stored anatomical models. We will be discussing the overall project goals and the results to date. Digital anatomical models are 3 dimensional, solid model representations of normal anatomy. The digital representations are electronically stored and can be manipulated and displayed on a computer graphics workstation. A digital database of anatomical structures can be used in conjunction with gross dissection in teaching normal anatomy to first year students in the professional curriculum. The computer model gives students the opportunity to "discover" relationships between anatomical structures that may have been destroyed or may not be obvious in the gross dissection. By using a digital database, the student will have the ability to view and manipulate anatomical structures in ways that are not available through interactive video disk (IVD). IVD constrains the student to preselected views and sections stored on the disk.

  13. 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.

  14. Landscapes of the Digital Baroque.

    PubMed

    Singh, Gary

    2016-01-01

    Alvaro Ocampo traversed many landscapes to arrive at his current space in the digital art landscape. Eventually, the artist then made his way to the digital world, where he is no longer subjected to the tyranny of the one-off. He believes digital art is the new version of traditional etching in the way that it eliminates the idea of the one original piece of art.

  15. 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.

  16. 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).

  17. National Digital Orthophoto Program

    USGS Publications Warehouse

    ,; ,; ,; ,; ,

    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.

  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. Direct to Digital Holography

    SciTech Connect

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

    2002-06-15

    In this 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.

  20. 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.

  1. 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.

  2. 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.

  3. Convex Digital Solids.

    DTIC Science & Technology

    1980-08-01

    where each face F. of 11(R) is represented by a sequence of its1 vertices. A lo)rithm CONVEXHULL(S,H(S) ,k) 2.1. Obtain CP(S), the set of corner...two. A chain is a finite sequence of digital points such that every element of the sequence except the first is a 6-neighbor of its predecessor. A set R...tno Lube wnosu edge is o1 length n. S is represented by a run lenqth code [121 such that RC(i,j) is a finite sequence of run lkLjntns of U’s

  4. 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.

  5. [Dichotic digit test. Case].

    PubMed

    Zenker Castro, Franz; Fernández Belda, Rafael; Barajas de Prat, José Juan

    2008-12-01

    In this study we present a case of a 71-year-old female patient with sensorineural hearing loss and fitted with bilateral hearing aids. The patient complained of scant benefit from the hearing aid fitting with difficulties in understanding speech with background noise. The otolaryngology examination was normal. Audiological tests revealed bilateral sensorineural hearing loss with threshold values of 51 and 50 dB HL in the right and left ear. The Dichotic Digit Test was administered in a divided attention mode and focalizing the attention to each ear. Results in this test are consistent with a Central Auditory Processing Disorder.

  6. 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.

  7. Digital receiver study and implementation

    NASA Technical Reports Server (NTRS)

    Fogle, D. A.; Lee, G. M.; Massey, J. C.

    1972-01-01

    Computer software was developed which makes it possible to use any general purpose computer with A/D conversion capability as a PSK receiver for low data rate telemetry processing. Carrier tracking, bit synchronization, and matched filter detection are all performed digitally. To aid in the implementation of optimum computer processors, a study of general digital processing techniques was performed which emphasized various techniques for digitizing general analog systems. In particular, the phase-locked loop was extensively analyzed as a typical non-linear communication element. Bayesian estimation techniques for PSK demodulation were studied. A hardware implementation of the digital Costas loop was developed.

  8. 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.

  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. 47 CFR 74.787 - Digital licensing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Digital licensing. 74.787 Section 74.787... Booster Stations § 74.787 Digital licensing. (a) Applications for digital low power television and television translator stations—(1) Applications for digital conversion. Applications for digital...

  11. 47 CFR 74.787 - Digital licensing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital licensing. 74.787 Section 74.787... Booster Stations § 74.787 Digital licensing. (a) Applications for digital low power television and television translator stations—(1) Applications for digital conversion. Applications for digital...

  12. 47 CFR 74.787 - Digital licensing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Digital licensing. 74.787 Section 74.787... Booster Stations § 74.787 Digital licensing. (a) Applications for digital low power television and television translator stations—(1) Applications for digital conversion. Applications for digital...

  13. 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…

  14. Digital dental photography. Part 3: Principles of digital photography.

    PubMed

    Ahmad, I

    2009-05-23

    Although we live in a digital age, our knowledge of the processes and technology involved is often limited. As a foundation to understanding the subsequent parts of this series, this part describes the fundamental aspects of digital photography, which includes the sensors, processing and display.

  15. 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…

  16. 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…

  17. 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…

  18. 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)

  19. 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…

  20. Digital Libraries Are Much More than Digitized Collections.

    ERIC Educational Resources Information Center

    Peters, Peter Evan

    1995-01-01

    The digital library encompasses the application of high-performance computers and networks to the production, distribution, management, and use of knowledge in research and education. A joint project by three federal agencies, which is investing in digital library initiatives at six universities, is discussed. A sidebar provides issues to consider…

  1. Digital lattice gauge theories

    NASA Astrophysics Data System (ADS)

    Zohar, Erez; Farace, Alessandro; Reznik, Benni; Cirac, J. Ignacio

    2017-02-01

    We propose a general scheme for a digital construction of lattice gauge theories with dynamical fermions. In this method, the four-body interactions arising in models with 2 +1 dimensions and higher are obtained stroboscopically, through a sequence of two-body interactions with ancillary degrees of freedom. This yields stronger interactions than the ones obtained through perturbative methods, as typically done in previous proposals, and removes an important bottleneck in the road towards experimental realizations. The scheme applies to generic gauge theories with Lie or finite symmetry groups, both Abelian and non-Abelian. As a concrete example, we present the construction of a digital quantum simulator for a Z3 lattice gauge theory with dynamical fermionic matter in 2 +1 dimensions, using ultracold atoms in optical lattices, involving three atomic species, representing the matter, gauge, and auxiliary degrees of freedom, that are separated in three different layers. By moving the ancilla atoms with a proper sequence of steps, we show how we can obtain the desired evolution in a clean, controlled way.

  2. 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.

  3. 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.

  4. Programmable digital modem

    NASA Astrophysics Data System (ADS)

    Poklemba, John J.

    1991-11-01

    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.

  5. 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.

  6. 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.

  7. Digital Media and Emergent Literacy

    ERIC Educational Resources Information Center

    Hisrich, Katy; Blanchard, Jay

    2009-01-01

    This article discusses digital media and its potential effects on emergent literacy skills development for young children. While the impact of digital media exposure on children's emergent literacy development is largely unknown, it is becoming a significant issue, as more and more young children throughout the world observe and use various forms…

  8. Digital Media Stories for Persuasion

    ERIC Educational Resources Information Center

    Leopold, Lisa

    2010-01-01

    Digital media story-telling (which enhances traditional oral story-telling with images, music, and text) has been a focus of recent scholarship for its potential to produce numerous educational benefits. Through digital media storytelling, students' imagination, creativity, critical thinking, writing, public speaking, and organizational or…

  9. Digital Image Analysis of Cereals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Image analysis is the extraction of meaningful information from images, mainly digital images by means of digital processing techniques. The field was established in the 1950s and coincides with the advent of computer technology, as image analysis is profoundly reliant on computer processing. As t...

  10. All-digital QPSK modulator

    NASA Technical Reports Server (NTRS)

    Burgess, R. W.; Julian, R. L.

    1980-01-01

    Circuit consisting to only four components (2 IC chips and 2 time delay devices) modulates RF signal with 2 asynchronous digital data signals. Digital modulator is virtually free of amplitude modulation, is not subject to temperature effects from other components, dissipates less power, and is far simpler than its analog predecessors.

  11. Measuring Distances Using Digital Cameras

    ERIC Educational Resources Information Center

    Kendal, Dave

    2007-01-01

    This paper presents a generic method of calculating accurate horizontal and vertical object distances from digital images taken with any digital camera and lens combination, where the object plane is parallel to the image plane or tilted in the vertical plane. This method was developed for a project investigating the size, density and spatial…

  12. Essays on the Digital Divide

    ERIC Educational Resources Information Center

    Abdelfattah, Belal M. T.

    2013-01-01

    The digital divide is a phenomenon that is globally persistent, despite rapidly decreasing costs in technology. While much of the variance in the adoption and use of information communication technology (ICT) that defines the digital divide can be explained by socioeconomic and demographic variables, there is still significant unaccounted variance…

  13. Three Essays on Digital Evolution

    ERIC Educational Resources Information Center

    Zhang, Zhewei

    2016-01-01

    Digital products are rapidly shaping our world into a ubiquitous computing world. Because of its unique characteristics, digital artifacts are generative and highly evolving through the recombination of existing elements as well as by the invention of new elements. In this thesis, I first propose an evolutionary view to examine how digital…

  14. Digital Portfolios: Documenting Student Growth

    ERIC Educational Resources Information Center

    Cramer, Matthew

    2009-01-01

    The digital portfolio process at Camino Nuevo High School (CNHS) offers an essential 21st century skill to students. All students are trained in basic web design to build and maintain their digital portfolios. These skills equip them with tools they will likely use in their future endeavors in college and the professional world. Teachers at CNHS…

  15. Digital Libraries on the Internet.

    ERIC Educational Resources Information Center

    Sharon, Taly; Frank, Ariel J.

    This paper discusses digital libraries on the Internet. The resource repository hierarchy, consisting of two major paradigms, search engines (SEs) and digital libraries, is presented. SEs are classified into three categories: basic-SE, directory, and meta-SE. The following six major characteristics of a library are summarized: collection of data…

  16. Going Digital in Rural America.

    ERIC Educational Resources Information Center

    Malecki, Edward J.

    This paper examines the extent to which rural America is digital--has access to the Internet and to newer technologies such as wireless broadband--and discusses rural supply and demand for "going digital." Supply aspects include issues of both infrastructure and public policy. Demand aspects include entrepreneurs (business users) and…

  17. Simulated Laboratory in Digital Logic.

    ERIC Educational Resources Information Center

    Cleaver, Thomas G.

    Design of computer circuits used to be a pencil and paper task followed by laboratory tests, but logic circuit design can now be done in half the time as the engineer accesses a program which simulates the behavior of real digital circuits, and does all the wiring and testing on his computer screen. A simulated laboratory in digital logic has been…

  18. Preservation Methods for Digital Library

    ERIC Educational Resources Information Center

    Rajendran, L.; Venkatesan, M.; Kanthimathi, S.

    2005-01-01

    Going digital is the way to minimize handling of damaged materials, but the imaging process is demanding and must be done with oversight by preservation staff and with a high enough level of quality to ensure the reusability of the archival electronic file for as long as possible. This paper focuses on the scope and needs of digital preservation,…

  19. Digital Imagery, Preservation and Access.

    ERIC Educational Resources Information Center

    Lesk, Michael; Lynn, M. Stuart

    1990-01-01

    These two reports published by the Commission on Preservation and Access (CPA) include a comparison of digital and microfilm imagery, as well as discussions of chemical deacidification; ASCII (nonimage) files; and storage, conversion, and transmission considerations. A structured glossary of terms relating to media conversion and digital computer…

  20. Semantic Research for Digital Libraries.

    ERIC Educational Resources Information Center

    Chen, Hsinchun

    1999-01-01

    Discusses the need for semantic research in digital libraries to help overcome interoperability problems. Highlights include federal initiatives; semantic analysis; knowledge representations; human-computer interactions and information visualization; and the University of Illinois DLI (Digital Libraries Initiative) project through partnership with…

  1. Digital Publishing: Imperfect, but Improving

    ERIC Educational Resources Information Center

    Boettcher, Judith V.

    2007-01-01

    Digital publishing is a field lurching along many paths and alleyways of experimentation. For their potential influence, however, recent approaches bear watching. In this article, the author shares the story of Jason on his personal decision-making struggles on using digital versions against conventional textbooks. The author also discusses…

  2. Continuous Representations of Digital Images.

    DTIC Science & Technology

    1985-10-01

    adjacency topology on a 2D digital image S is well represented by the standard Euclidean topology on F (S ) (resp. U (S )). The topological spaces F(S) and U...space R as primitive approximation of a 2D digital image S by con- tinuous topological spaces . This space F (S) is not new. In fact, it has always been

  3. Digital Literacies of the Cybergirl

    ERIC Educational Resources Information Center

    Thomas, Angela

    2004-01-01

    This article explores the nexus between digital literacies and identity in the online graphical chat environment of the "palace". With a focus on the adolescent cybergirl, it examines how girls use words and images to create a digital presence, and in so doing, "write" their bodies and their selves. I discuss how the cybergirl is discursively…

  4. South Korean Digital Textbook Project

    ERIC Educational Resources Information Center

    Kim, Jackie Hee-Young; Jung, Hye-Yoon

    2010-01-01

    South Korea has adopted the widespread use of digital textbooks. Part school reform and part an effort to prepare today's children for tomorrow's challenging world, the way in which this effort was implemented and the lessons learned are valuable. This article highlights the history of the digital textbook project and compares printed textbooks…

  5. Digital Architecture Planning Model

    SciTech Connect

    Oxstrand, Johanna Helene; Al Rashdan, Ahmad Yahya Mohammad; Bly, Aaron Douglas; Rice, Brandon Charles; Fitzgerald, Kirk; Wilson, Keith Leon

    2016-03-01

    As part of the U.S. Department of Energy’s Light Water Reactor Sustainability Program, the Digital Architecture (DA) Project focuses on providing a model that nuclear utilities can refer to when planning deployment of advanced technologies. The digital architecture planning model (DAPM) is the methodology for mapping power plant operational and support activities into a DA that unifies all data sources needed by the utilities to operate their plants. The DA is defined as a collection of information technology capabilities needed to support and integrate a wide spectrum of real-time digital capabilities for performance improvements of nuclear power plants. DA can be thought of as integration of the separate instrumentation and control and information systems already in place in nuclear power plants, which are brought together for the purpose of creating new levels of automation in plant work activities. A major objective in DAPM development was to survey all key areas that needed to be reviewed in order for a utility to make knowledgeable decisions regarding needs and plans to implement a DA at the plant. The development was done in two steps. First, researchers surveyed the nuclear industry in order to learn their near-term plans for adopting new advanced capabilities and implementing a network (i.e., wireless and wire) infrastructure throughout the plant, including the power block. Secondly, a literature review covering regulatory documents, industry standards, and technical research reports and articles was conducted. The objective of the review was to identify key areas to be covered by the DAPM, which included the following: 1. The need for a DA and its benefits to the plant 2. Resources required to implement the DA 3. Challenges that need to be addressed and resolved to implement the DA 4. Roles and responsibilities of the DA implementation plan. The DAPM was developed based on results from the survey and the literature review. Model development, including

  6. Digital imaging overview.

    PubMed

    Carrino, John A

    2003-07-01

    Digital imaging consists of digital acquisition modalities, image, and information management systems. All modalities are available to be purchased as digital acquisition devices. Image management has been the domain for PACSs. PACSs are complex systems designed to transmit, store, and display medical images. They use and rely on many types of different information and display technologies. The initial focus for PACSs has been on solving the engineering issues associated with the transfer of large image data sets and the suitability of softcopy displays for diagnosis particular to the human visual system. For operating within a centralized radiology department, these are largely solved. However, for enterprise wide dissemination and distribution, there are still challenges in the form of expedient transfer syntaxes and image quality, but these are also being effectively addressed. Information management is the domain of the RIS. One of the goals of radiology management should encompass the development of a robust practice environment that emphasizes workflow enhancements with seamless integration of decision support tools. The concept of "person-machine" systems emphasizes taking full advantage of both human and machine capabilities with a capacity to grow and change function. As the computer capabilities increase, more jobs can be relinquished to the machine. The physician can then focus on tasks that require more complex judgment and comprehension. The goal of this human-machine hybrid is to have more power than either of its components alone. This multifaceted role will most likely be embedded in the background having agents query and retrieve context specific information to be presented to the user. As augmenters of human talent, computers can turn data into information and information into knowledge. Medical imaging is a beneficiary of the information technology developments driven by the consumer and business sectors. Although these applications of

  7. [Full-field digital mammography].

    PubMed

    Bick, U

    2000-12-01

    Due to the extremely high image quality requirements in mammography, there has for a long time been no adequate digital alternative to conventional film-screen mammography. The longest experience so far exists with digital mammography on the basis of storage phosphor (CR) systems. However, at normal dose this technique has a relatively poor signal-to-noise ratio and has not found general acceptance. Recently three novel systems for digital mammography by the companies Fischer (slot-scan detector), Trex (CCD-array), and GE (amorphous silicon detector) have been introduced and are currently under clinical investigation. The main advantage of digital mammography is the linear relationship between dose and detector signal with the possibility of a tailored optimization of image contrast. Other advantages include digital image storage, telemammography, and computer-assisted diagnosis.

  8. Digital quadrature phase detection

    DOEpatents

    Smith, J.A.; Johnson, J.A.

    1992-05-26

    A system for detecting the phase of a frequency or phase modulated signal that includes digital quadrature sampling of the frequency or phase modulated signal at two times that are one quarter of a cycle of a reference signal apart, determination of the arctangent of the ratio of a first sampling of the frequency or phase modulated signal to the second sampling of the frequency or phase modulated signal, and a determination of quadrant in which the phase determination is increased by 2[pi] when the quadrant changes from the first quadrant to the fourth quadrant and decreased by 2[pi] when the quadrant changes from the fourth quadrant to the first quadrant whereby the absolute phase of the frequency or phase modulated signal can be determined using an arbitrary reference convention. 6 figs.

  9. Digital Optical Control System

    NASA Astrophysics Data System (ADS)

    Jordan, David H.; Tipton, Charles A.; Christmann, Charles E.; Hochhausler, Nils P.

    1988-09-01

    We describe the digital optical control system (DOGS), a state-of-the-art controller for electrical feedback in an optical system. The need for a versatile optical controller arose from a number of unique experiments being performed by the Air Force Weapons Laboratory. These experiments use similar detectors and actuator-controlled mirrors, but the control requirements vary greatly. The experiments have in common a requirement for parallel control systems. The DOGS satisfies these needs by allowing several control systems to occupy a single chassis with one master controller. The architecture was designed to allow upward compatibility with future configurations. Combinations of off-the-shelf and custom boards are configured to meet the requirements of each experiment. The configuration described here was used to control piston error to X/80 at a wavelength of 0.51 Am. A peak sample rate of 8 kHz, yielding a closed loop bandwidth of 800 Hz, was achieved.

  10. Robustness in Digital Hardware

    NASA Astrophysics Data System (ADS)

    Woods, Roger; Lightbody, Gaye

    The growth in electronics has probably been the equivalent of the Industrial Revolution in the past century in terms of how much it has transformed our daily lives. There is a great dependency on technology whether it is in the devices that control travel (e.g., in aircraft or cars), our entertainment and communication systems, or our interaction with money, which has been empowered by the onset of Internet shopping and banking. Despite this reliance, there is still a danger that at some stage devices will fail within the equipment's lifetime. The purpose of this chapter is to look at the factors causing failure and address possible measures to improve robustness in digital hardware technology and specifically chip technology, giving a long-term forecast that will not reassure the reader!

  11. Photonics meet digital art

    NASA Astrophysics Data System (ADS)

    Curticapean, Dan; Israel, Kai

    2014-09-01

    The paper focuses on the work of an interdisciplinary project between photonics and digital art. The result is a poster collection dedicated to the International Year of Light 2015. In addition, an internet platform was created that presents the project. It can be accessed at http://www.magic-of-light.org/iyl2015/index.htm. From the idea to the final realization, milestones with tasks and steps will be presented in the paper. As an interdisciplinary project, students from technological degree programs were involved as well as art program students. The 2015 Anniversaries: Alhazen (1015), De Caus (1615), Fresnel (1815), Maxwell (1865), Einstein (1905), Penzias Wilson, Kao (1965) and their milestone contributions in optics and photonics will be highlighted.

  12. Digital TV processing system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Two digital video data compression systems directly applicable to the Space Shuttle TV Communication System were described: (1) For the uplink, a low rate monochrome data compressor is used. The compression is achieved by using a motion detection technique in the Hadamard domain. To transform the variable source rate into a fixed rate, an adaptive rate buffer is provided. (2) For the downlink, a color data compressor is considered. The compression is achieved first by intra-color transformation of the original signal vector, into a vector which has lower information entropy. Then two-dimensional data compression techniques are applied to the Hadamard transformed components of this last vector. Mathematical models and data reliability analyses were also provided for the above video data compression techniques transmitted over a channel encoded Gaussian channel. It was shown that substantial gains can be achieved by the combination of video source and channel coding.

  13. Digital quadrature phase detection

    DOEpatents

    Smith, James A.; Johnson, John A.

    1992-01-01

    A system for detecting the phase of a frequency of phase modulated signal that includes digital quadrature sampling of the frequency or phase modulated signal at two times that are one quarter of a cycle of a reference signal apart, determination of the arctangent of the ratio of a first sampling of the frequency or phase modulated signal to the second sampling of the frequency or phase modulated signal, and a determination of quadrant in which the phase determination is increased by 2.pi. when the quadrant changes from the first quadrant to the fourth quadrant and decreased by 2.pi. when the quadrant changes from the fourth quadrant to the first quadrant whereby the absolute phase of the frequency or phase modulated signal can be determined using an arbitrary reference convention.

  14. Procedures and Guidelines for Digitization (Scanning)

    EPA Pesticide Factsheets

    These documents establishes EPA's approach for creating digitized versions of Agency documents and establishes standards for capturing digitized content from paper and microform Agency documents and records.

  15. Digital Writing for a Digital Age Peer Editing in Traditional versus Digital Writing Formats

    ERIC Educational Resources Information Center

    Jelderks, Christopher Jeffery

    2013-01-01

    Understanding the merits and demerits of new technology and how it may or may not work within traditional pedagogical methods is important. This study, therefore, examined the effects of traditional versus digital peer-editing to understand how digital peer-editing affects student writing achievement in a rural public middle school environment. It…

  16. Digital Broadband Content: Digital Content Strategies and policies. OECD Digital Economy Papers, No. 119

    ERIC Educational Resources Information Center

    OECD Publishing (NJ1), 2006

    2006-01-01

    The development of digital content raises new issues as rapid technological developments challenge existing business models and government policies. This OECD study identifies and discusses six groups of business and public policy issues and illustrates these with existing and potential OECD Digital Content Strategies and Policies: (1) Innovation…

  17. Digital Data Set of 14-Digit Hydrologic Units in Indiana

    USGS Publications Warehouse

    DeBroka, Krysten M.; Cohen, David A.; Dunn, Robert E.; Nielsen, Bruce J.

    1999-01-01

    A hydrologic unit is an area of land that can contribute surface-water runoff to a designated outlet point. As part of an initiative to create a nationally uniform hydrologic-unit data base, the U.S. Geological Survey and the Natural Resources Conservation Service, in cooperation with the Indiana Department of Environmental Management and the Indiana Department of Natural Resources Division of Water, created a Geographic Information System digital data set of 14-digit hydrologic units in Indiana. The digital data set consists of arcs and polygons defining hydrologic units in Indiana.

  18. Digital terrain tapes: user guide

    USGS Publications Warehouse

    ,

    1980-01-01

    DMATC's digital terrain tapes are a by-product of the agency's efforts to streamline the production of raised-relief maps. In the early 1960's DMATC developed the Digital Graphics Recorder (DGR) system that introduced new digitizing techniques and processing methods into the field of three-dimensional mapping. The DGR system consisted of an automatic digitizing table and a computer system that recorded a grid of terrain elevations from traces of the contour lines on standard topographic maps. A sequence of computer accuracy checks was performed and then the elevations of grid points not intersected by contour lines were interpolated. The DGR system produced computer magnetic tapes which controlled the carving of plaster forms used to mold raised-relief maps. It was realized almost immediately that this relatively simple tool for carving plaster molds had enormous potential for storing, manipulating, and selectively displaying (either graphically or numerically) a vast number of terrain elevations. As the demand for the digital terrain tapes increased, DMATC began developing increasingly advanced digitizing systems and now operates the Digital Topographic Data Collection System (DTDCS). With DTDCS, two types of data elevations as contour lines and points, and stream and ridge lines are sorted, matched, and resorted to obtain a grid of elevation values for every 0.01 inch on each map (approximately 200 feet on the ground). Undefined points on the grid are found by either linear or or planar interpolation.

  19. Artifacts in digital coincidence timing

    SciTech Connect

    Moses, W. W.; Peng, Q.

    2014-10-16

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator.All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the 'optimal' method. In conclusion, the purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization.

  20. Artifacts in Digital Coincidence Timing

    PubMed Central

    Moses, W. W.; Peng, Q.

    2014-01-01

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator. All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e., the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the “optimal” method. The purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization. PMID:25321885

  1. Digital Earth Watch: Investigating the World with Digital Cameras

    NASA Astrophysics Data System (ADS)

    Gould, A. D.; Schloss, A. L.; Beaudry, J.; Pickle, J.

    2015-12-01

    Every digital camera including the smart phone camera can be a scientific tool. Pictures contain millions of color intensity measurements organized spatially allowing us to measure properties of objects in the images. This presentation will demonstrate how digital pictures can be used for a variety of studies with a special emphasis on using repeat digital photographs to study change-over-time in outdoor settings with a Picture Post. Demonstrations will include using inexpensive color filters to take pictures that enhance features in images such as unhealthy leaves on plants, or clouds in the sky. Software available at no cost from the Digital Earth Watch (DEW) website that lets students explore light, color and pixels, manipulate color in images and make measurements, will be demonstrated. DEW and Picture Post were developed with support from NASA. Please visit our websites: DEW: http://dew.globalsystemsscience.orgPicture Post: http://picturepost.unh.edu

  2. The digital Emily project: achieving a photorealistic digital actor.

    PubMed

    Alexander, Oleg; Rogers, Mike; Lambeth, William; Chiang, Jen-Yuan; Ma, Wan-Chun; Wang, Chuan-Chang; Debevec, Paul

    2010-01-01

    The Digital Emily Project uses advanced face scanning, character rigging, performance capture, and compositing to achieve one of the world's first photorealistic digital facial performances. The project scanned the geometry and reflectance of actress Emily O'Brien's face in 33 poses, showing different emotions, gaze directions, and lip formations in a light stage. These high-resolution scans-accurate to skin pores and fine wrinkles-became the basis for building a blendshape-based facial-animation rig whose expressions closely matched the scans. The blendshape rig drove displacement maps to add dynamic surface detail. A video-based facial animation system animated the face according to the performance in a reference video, and the digital face was tracked onto the video's motion and rendered under the same illumination. The result was a realistic 3D digital facial performance credited as one of the first to cross the "uncanny valley" between animated and fully human performances.

  3. Digitalizing the Circular Economy

    NASA Astrophysics Data System (ADS)

    Reuter, Markus A.

    2016-12-01

    Metallurgy is a key enabler of a circular economy (CE), its digitalization is the metallurgical Internet of Things (m-IoT). In short: Metallurgy is at the heart of a CE, as metals all have strong intrinsic recycling potentials. Process metallurgy, as a key enabler for a CE, will help much to deliver its goals. The first-principles models of process engineering help quantify the resource efficiency (RE) of the CE system, connecting all stakeholders via digitalization. This provides well-argued and first-principles environmental information to empower a tax paying consumer society, policy, legislators, and environmentalists. It provides the details of capital expenditure and operational expenditure estimates. Through this path, the opportunities and limits of a CE, recycling, and its technology can be estimated. The true boundaries of sustainability can be determined in addition to the techno-economic evaluation of RE. The integration of metallurgical reactor technology and systems digitally, not only on one site but linking different sites globally via hardware, is the basis for describing CE systems as dynamic feedback control loops, i.e., the m-IoT. It is the linkage of the global carrier metallurgical processing system infrastructure that maximizes the recovery of all minor and technology elements in its associated refining metallurgical infrastructure. This will be illustrated through the following: (1) System optimization models for multimetal metallurgical processing. These map large-scale m-IoT systems linked to computer-aided design tools of the original equipment manufacturers and then establish a recycling index through the quantification of RE. (2) Reactor optimization and industrial system solutions to realize the "CE (within a) Corporation—CEC," realizing the CE of society. (3) Real-time measurement of ore and scrap properties in intelligent plant structures, linked to the modeling, simulation, and optimization of industrial extractive process

  4. Digital phase-locked loop

    NASA Technical Reports Server (NTRS)

    Cliff, R. A. (Inventor)

    1975-01-01

    An digital phase-locked loop is provided for deriving a loop output signal from an accumulator output terminal. A phase detecting exclusive OR gate is fed by the loop digital input and output signals. The output of the phase detector is a bi-level digital signal having a duty cycle indicative of the relative phase of the input and output signals. The accumulator is incremented at a first rate in response to a first output level of the phase detector and at a second rate in response to a second output level of the phase detector.

  5. Digital Baseband Architecture For Transponder

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M.; Yeh, Hen-Geul

    1995-01-01

    Proposed advanced transponder for long-distance radio communication system with turnaround ranging contains carrier-signal-tracking loop including baseband digital "front end." For reduced cost, transponder includes analog intermediate-frequency (IF) section and analog automatic gain control (AGC) loop at first of two IF mixers. However, second IF mixer redesigned to ease digitization of baseband functions. To conserve power and provide for simpler and smaller transponder hardware, baseband digital signal-processing circuits designed to implement undersampling scheme. Furthermore, sampling scheme and sampling frequency chosen so redesign involves minimum modification of command-detector unit (CDU).

  6. Digital Demodulator For Advanced Receiver

    NASA Technical Reports Server (NTRS)

    Sadr, Ramin; Hurd, William J.

    1990-01-01

    Complexity and cost reduced by new design for half-band filters. Digital demodulator designed for use in reception of phase- and amplitude-modulated digital signals of bandwidths up to 15 MHz on microwave carriers. System performs coherent demodulation in phase and in quadrature with carrier locked in phase to intermediate frequency of 10 MHz. Design suitable for fabrication in very-large-scale integrated circuitry. Principal innovative feature of demodulator is design of half-band digital low-pass filters that remove sum-frequency components.

  7. Digital Fire Control Systems Support

    DTIC Science & Technology

    2012-09-27

    Systems ( DFCS ) for the M119A2 and M777A2. The DFCS is a fully integrated digital fire control system that has weapon platform application to the...Lightweight 155 mm (LW155) Towed Howitzer and the M119A2 Lightweight 105mm Towed Howitzer. 15. SUBJECT TERMS Digital Fire Control Systems ( DFCS ) 16...Joint Lightweight 155, has been tasked to develop and maintain the Digital Fire Control Systems ( DFCS ) for the M119A2 and M777A2. The DFCS is a fully

  8. All digital pulsewidth control loop

    NASA Astrophysics Data System (ADS)

    Huang, Hong-Yi; Jan, Shiun-Dian; Pu, Ruei-Iun

    2013-03-01

    This work presents an all-digital pulsewidth control loop (ADPWCL). The proposed system accepts a wide range of input duty cycles and performs a fast correction to the target output pulsewidth. An all-digital delay-locked loop (DLL) with fast locking time using a simplified time to digital converter and a new differential two-step delay element is proposed. The area of the delay element is much smaller than that in conventional designs, while having the same delay range. A test chip is verified in a 0.18-µm CMOS process. The measured duty cycle ranges from 4% to 98% with 7-bit resolution.

  9. Lesion detectability in digital radiography

    NASA Astrophysics Data System (ADS)

    Gagne, Robert M.; Boswell, Jonathan S.; Myers, Kyle J.; Peter, Guillaume

    2001-06-01

    The usefulness of Fourier-based measures of imaging performance has come into question for the evaluation of digital imaging systems. Figures of merit such as detective quantum efficiency are relevant for linear, shift-invariant systems with stationary noise. However, no digital imaging system is shift invariant, and realistic images do not satisfy the stationarity condition. Our methods for task- based evaluation of imaging systems, based on lesion detectability, do not require such assumptions. We have computed the performance of Hotelling and nonprewhitening matched-filter observers for the task of lesion detection in digital radiography.

  10. Digital Guided Weapons Technology. Volume 1. Digital Processor System Studies

    DTIC Science & Technology

    1976-11-01

    controlled during midcourse flight by navigation based on a combination of inertial sensor information (illustrated as an IMU module) and LORAN receiver... design weapon was described. In the latter situation, the integration subsystem is a combination of a digital processor and a harness with dedicated...subsystem for a fixed- design weapon, as noted previously, is the combination of the digital processor and a harness with dedicated links to the

  11. Digital atlas of Oklahoma

    USGS Publications Warehouse

    Rea, A.H.; Becker, C.J.

    1997-01-01

    This compact disc contains 25 digital map data sets covering the State of Oklahoma that may be of interest to the general public, private industry, schools, and government agencies. Fourteen data sets are statewide. These data sets include: administrative boundaries; 104th U.S. Congressional district boundaries; county boundaries; latitudinal lines; longitudinal lines; geographic names; indexes of U.S. Geological Survey 1:100,000, and 1:250,000-scale topographic quadrangles; a shaded-relief image; Oklahoma State House of Representatives district boundaries; Oklahoma State Senate district boundaries; locations of U.S. Geological Survey stream gages; watershed boundaries and hydrologic cataloging unit numbers; and locations of weather stations. Eleven data sets are divided by county and are located in 77 county subdirectories. These data sets include: census block group boundaries with selected demographic data; city and major highways text; geographic names; land surface elevation contours; elevation points; an index of U.S. Geological Survey 1:24,000-scale topographic quadrangles; roads, streets and address ranges; highway text; school district boundaries; streams, river and lakes; and the public land survey system. All data sets are provided in a readily accessible format. Most data sets are provided in Digital Line Graph (DLG) format. The attributes for many of the DLG files are stored in related dBASE(R)-format files and may be joined to the data set polygon attribute or arc attribute tables using dBASE(R)-compatible software. (Any use of trade names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.) Point attribute tables are provided in dBASE(R) format only, and include the X and Y map coordinates of each point. Annotation (text plotted in map coordinates) are provided in AutoCAD Drawing Exchange format (DXF) files. The shaded-relief image is provided in TIFF format. All data sets except the shaded

  12. Digital hum filtering

    USGS Publications Warehouse

    Knapp, R.W.; Anderson, N.L.

    1994-01-01

    Data may be overprinted by a steady-state cyclical noise (hum). Steady-state indicates that the noise is invariant with time; its attributes, frequency, amplitude, and phase, do not change with time. Hum recorded on seismic data usually is powerline noise and associated higher harmonics; leakage from full-waveform rectified cathodic protection devices that contain the odd higher harmonics of powerline frequencies; or vibrational noise from mechanical devices. The fundamental frequency of powerline hum may be removed during data acquisition with the use of notch filters. Unfortunately, notch filters do not discriminate signal and noise, attenuating both. They also distort adjacent frequencies by phase shifting. Finally, they attenuate only the fundamental mode of the powerline noise; higher harmonics and frequencies other than that of powerlines are not removed. Digital notch filters, applied during processing, have many of the same problems as analog filters applied in the field. The method described here removes hum of a particular frequency. Hum attributes are measured by discrete Fourier analysis, and the hum is canceled from the data by subtraction. Errors are slight and the result of the presence of (random) noise in the window or asynchrony of the hum and data sampling. Error is minimized by increasing window size or by resampling to a finer interval. Errors affect the degree of hum attenuation, not the signal. The residual is steady-state hum of the same frequency. ?? 1994.

  13. GENERALIZED DIGITAL CONTOURING PROGRAM

    NASA Technical Reports Server (NTRS)

    Jones, R. L.

    1994-01-01

    This is a digital computer contouring program developed by combining desirable characteristics from several existing contouring programs. It can easily be adapted to many different research requirements. The overlaid structure of the program permits desired modifications to be made with ease. The contouring program performs both the task of generating a depth matrix from either randomly or regularly spaced surface heights and the task of contouring the data. Each element of the depth matrix is computed as a weighted mean of heights predicted at an element by planes tangent to the surface at neighboring control points. Each contour line is determined by its intercepts with the sides of geometrical figures formed by connecting the various elements of the depth matrix with straight lines. Although contour charts are usually thought of as being two-dimensional pictorial representations of topographic formations of land masses, they can also be useful in portraying data which are obtained during the course of research in various scientific disciplines and which would ordinarily be tabulated. Any set of data which can be referenced to a two-dimensional coordinate system can be graphically represented by this program. This program is written in FORTRAN IV and ASSEMBLER for batch execution and has been implemented on the CDC 6000 Series. This program was developed in 1971.

  14. DVD - digital versatile disks

    SciTech Connect

    Gaunt, R.

    1997-05-01

    An international standard has emerged for the first true multimedia format. Digital Versatile Disk (by its official name), you may know it as Digital Video Disks. DVD has applications in movies, music, games, information CD-ROMS, and many other areas where massive amounts of digital information is needed. Did I say massive amounts of data? Would you believe over 17 gigabytes on a single piece of plastic the size of an audio-CD? That`s the promise, at least, by the group of nine electronics manufacturers who have agreed to the format specification, and who hope to make this goal a reality by 1998. In this major agreement, which didn`t come easily, the manufacturers will combine Sony and Phillip`s one side double-layer NMCD format with Toshiba and Matsushita`s double sided Super-Density disk. By Spring of this year, they plan to market the first 4.7 gigabyte units. The question is: Will DVD take off? Some believe that read-only disks recorded with movies will be about as popular as video laser disks. They say that until the eraseable/writable DVD arrives, the consumer will most likely not buy it. Also, DVD has a good market for replacement of CD- Roms. Back in the early 80`s, the international committee deciding the format of the audio compact disk decided its length would be 73 minutes. This, they declared, would allow Beethoven`s 9th Symphony to be contained entirely on a single CD. Similarly, today it was agreed that playback length of a single sided, single layer DVD would be 133 minutes, long enough to hold 94% of all feature-length movies. Further, audio can be in Dolby`s AC-3 stereo or 5.1 tracks of surround sound, better than CD-quality audio (16-bits at 48kHz). In addition, there are three to five language tracks, copy protection and parental ``locks`` for R rated movies. DVD will be backwards compatible with current CD-ROM and audio CD formats. Added versatility comes by way of multiple aspect rations: 4:3 pan-scan, 4:3 letterbox, and 16:9 widescreen. MPEG

  15. Digital matched filter ASIC

    NASA Astrophysics Data System (ADS)

    Magill, D. T.; Edwards, G.

    The architecture of a digital matched filter (DMF) and the selected technology used is described. The characteristics of the DMF ASIC are summarized in tabular form. Three architectures are considered for the implementation of a DMF ASIC. First, there is the conventional trapped delay line architecture which requires a large adder tree. The second architecture is the systolic array DMF which consists of a number of identical stages cascaded together. The third architecture is the bank-of-correlators DMF, in which the reference code is recirculated around through the delay line. Since the objective is to maximize the length of the DMF, the tapped delay line architecture is selected. The tapped delay form is designed to support BPSK, QPSK, and OQPSK chip modulation. Matched filter lengths of up to 256 chips can be supported by cascading 4 ASICs. The DMF is designed as a gate array using an advanced double metal, 1.5 micron CMOS process. The regularity of FIR filter architecture allows the core of the device to be laid out very compactly, resulting in efficient usage of the gate array.

  16. Digital display of astronomical data

    NASA Astrophysics Data System (ADS)

    Grandi, S. A.

    1982-08-01

    A brief summary is given of techniques to enhance for photographic display digital astronomical images. The phenomenon of photographic deresolution is discussed and a proposed algorithm, the highpass squared filter, is presented to correct for this effect.

  17. Open data and digital morphology.

    PubMed

    Davies, Thomas G; Rahman, Imran A; Lautenschlager, Stephan; Cunningham, John A; Asher, Robert J; Barrett, Paul M; Bates, Karl T; Bengtson, Stefan; Benson, Roger B J; Boyer, Doug M; Braga, José; Bright, Jen A; Claessens, Leon P A M; Cox, Philip G; Dong, Xi-Ping; Evans, Alistair R; Falkingham, Peter L; Friedman, Matt; Garwood, Russell J; Goswami, Anjali; Hutchinson, John R; Jeffery, Nathan S; Johanson, Zerina; Lebrun, Renaud; Martínez-Pérez, Carlos; Marugán-Lobón, Jesús; O'Higgins, Paul M; Metscher, Brian; Orliac, Maëva; Rowe, Timothy B; Rücklin, Martin; Sánchez-Villagra, Marcelo R; Shubin, Neil H; Smith, Selena Y; Starck, J Matthias; Stringer, Chris; Summers, Adam P; Sutton, Mark D; Walsh, Stig A; Weisbecker, Vera; Witmer, Lawrence M; Wroe, Stephen; Yin, Zongjun; Rayfield, Emily J; Donoghue, Philip C J

    2017-04-12

    Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility.

  18. Digital Techniques for Laboratory Measurements

    ERIC Educational Resources Information Center

    Dart, S. Leonard

    1975-01-01

    Describes techniques and equipment intended to both improve laboratory measurements and also form a background for more advanced work by introducing the concepts of electronic and digital circuits. (GS)

  19. Digital image processing in cephalometric analysis.

    PubMed

    Jäger, A; Döler, W; Schormann, T

    1989-01-01

    Digital image processing methods were applied to improve the practicability of cephalometric analysis. The individual X-ray film was digitized by the aid of a high resolution microscope-photometer. Digital processing was done using a VAX 8600 computer system. An improvement of the image quality was achieved by means of various digital enhancement and filtering techniques.

  20. Building and Maintaining Digital Reference Services.

    ERIC Educational Resources Information Center

    Wasik, Joann M.

    2000-01-01

    Discusses digital reference services that provide subject expertise and information referral over the Internet to their users. Describes the history of digital reference, how digital reference services work, and explains a six-step process for building and maintaining digital reference services, including training, planning, and evaluating. (LRW)

  1. [The elementary discussion on digital implant dentistry].

    PubMed

    Su, Y C

    2016-04-09

    It is a digital age today. Exposed to all kinds of digital products in many fields. Certainly, implant dentistry is not exception. Digitalization could improve the outcomes and could decrease the complications of implant dentistry. This paper introduces the concepts, definitions, advantages, disadvantages, limitations and errors of digital implant dentistry.

  2. Imagers for digital still photography

    NASA Astrophysics Data System (ADS)

    Bosiers, Jan; Dillen, Bart; Draijer, Cees; Manoury, Erik-Jan; Meessen, Louis; Peters, Inge

    2006-04-01

    This paper gives an overview of the requirements for, and current state-of-the-art of, CCD and CMOS imagers for use in digital still photography. Four market segments will be reviewed: mobile imaging, consumer "point-and-shoot cameras", consumer digital SLR cameras and high-end professional camera systems. The paper will also present some challenges and innovations with respect to packaging, testing, and system integration.

  3. Digital-data receiver synchronization

    DOEpatents

    Smith, Stephen F.; Turner, Gary W.

    2005-08-02

    Digital-data receiver synchronization is provided with composite phase-frequency detectors, mutually cross-connected comparison feedback or both to provide robust reception of digital data signals. A single master clock can be used to provide frequency signals. Advantages can include fast lock-up time in moderately to severely noisy conditions, greater tolerance to noise and jitter when locked, and improved tolerance to clock asymmetries.

  4. A veterinary digital anatomical database.

    PubMed Central

    Snell, J. R.; Green, R.; Stott, G.; Van Baerle, S.

    1991-01-01

    This paper describes the Veterinary Digital Anatomical Database Project. The purpose of the project is to investigate the construction and use of digitally stored anatomical models. We will be discussing the overall project goals and the results to date. Digital anatomical models are 3 dimensional, solid model representations of normal anatomy. The digital representations are electronically stored and can be manipulated and displayed on a computer graphics workstation. A digital database of anatomical structures can be used in conjunction with gross dissection in teaching normal anatomy to first year students in the professional curriculum. The computer model gives students the opportunity to "discover" relationships between anatomical structures that may have been destroyed or may not be obvious in the gross dissection. By using a digital database, the student will have the ability to view and manipulate anatomical structures in ways that are not available through interactive video disk (IVD). IVD constrains the student to preselected views and sections stored on the disk. Images Figure 1 PMID:1807707

  5. Digital signal conditioning for flight test instrumentation

    NASA Technical Reports Server (NTRS)

    Bever, Glenn A.

    1991-01-01

    An introduction to digital measurement processes on aircraft is provided. Flight test instrumentation systems are rapidly evolving from analog-intensive to digital intensive systems, including the use of onboard digital computers. The topics include measurements that are digital in origin, as well as sampling, encoding, transmitting, and storing data. Particular emphasis is placed on modern avionic data bus architectures and what to be aware of when extracting data from them. Examples of data extraction techniques are given. Tradeoffs between digital logic families, trends in digital development, and design testing techniques are discussed. An introduction to digital filtering is also covered.

  6. Digital filtering: background and tutorial for psychophysiologists.

    PubMed

    Cook, E W; Miller, G A

    1992-05-01

    Digital filtering offers more to psychophysiologists than is commonly appreciated. An introduction is offered here to foster the explicit design and use of digital filters. Because of considerable confusion in the literature about terminology important to both analog and digital filtering, basic concepts are reviewed and clarified. Because some time series concepts are fundamental to digital filtering, these are also presented. Examples of filters commonly used in psychophysiology are given, and procedures are presented for the design and use of one type of digital filter. Properties of some types of digital filters are described, and the relative advantages of simple analog and digital filters are discussed.

  7. A historical perspective on digital hearing AIDS: how digital technology has changed modern hearing AIDS.

    PubMed

    Levitt, Harry

    2007-03-01

    This article provides the author's perspective on the development of digital hearing aids and how digital signal processing approaches have led to changes in hearing aid design. Major landmarks in the evolution of digital technology are identified, and their impact on the development of digital hearing aids is discussed. Differences between analog and digital approaches to signal processing in hearing aids are identified.

  8. Could digital imaging be an alternative for digital colorimeters?

    PubMed

    Caglar, Alper; Yamanel, Kivanc; Gulsahi, Kamran; Bagis, Bora; Ozcan, Mutlu

    2010-12-01

    This study evaluated the colour parameters of composite and ceramic shade guides determined using a colorimeter and digital imaging method with illuminants at different colour temperatures. Two different resin composite shade guides, namely Charisma (Heraeus Kulzer) and Premise (Kerr Corporation), and two different ceramic shade guides, Vita Lumin Vacuum (VITA Zahnfabrik) and Noritake (Noritake Co.), were evaluated at three different colour temperatures (2,700 K, 2,700-6,500 K, and 6500 K) of illuminants. Ten shade tabs were selected (A1, A2, A3, A3,5, A4, B1, B2, B3, C2 and C3) from each shade guide. CIE Lab values were obtained using digital imaging and a colorimeter (ShadeEye NCC Dental Chroma Meter, Shofu Inc.). The data were analysed using two-way ANOVA, and Pearson's correlation. While mean L* values of both composite and ceramic shade guides were not affected from the colour temperature, L* values obtained with the colorimeter showed significantly lower values than those of the digital imaging (p < 0.01). At combined 2,700-6500 K colour temperature, the means of a* values obtained from colorimeter and digital imaging did not show significant differences (p > 0.05). For both composite and ceramic shade guides, L* and b* values obtained from colorimeter and digital imaging method presented a high level of correlation. High-level correlations were also acquired for a* values in all shade guides except for the Charisma composite shade guide. Digital imaging method could be an alternative for the colorimeters unless the proper object-camera distance, digital camera settings and suitable illumination conditions could be supplied. However, variations in shade guides, especially for composites, may affect the correlation.

  9. Challenging the Digital Divide

    NASA Astrophysics Data System (ADS)

    Kembhavi, Ajit

    2006-08-01

    Vast quantities of astronomical data in the form of images, spectra and catalogues are now freely available over the internet, and tools for producing science from these resources are also becoming available, particularly through the emerging Virtual Observatories. In addition to this, most astronomical literature from research journals is available at no cost through the ADS and preprint service. This situation, in principle, provides equal opportunity to astronomers located anywhere in the world to participate in the process of discovery. The only requirement is that the astronomers have access to the internet, and a fertile imagination. But in the real world, astronomers in many countries have very limited bandwidth and computing power, and are therefore excluded from meaningful participation in astronomical research, even though they may have the ideas and experience to contribute substantially to the effort. The lack of connectivity and computing hardware also makes it difficult for astronomers in many countries from exposing adequately any data resources that they may have produced locally. This situation prevents many aspiring and experienced astronomers from reaching their creative potential, and from attracting young persons to the charms of modern astronomy; it also leads to opportunity loss to astronomy, as it loses out on the the human resources and fresh ideas and talents which astronomers from developing countries could bring to the subject. I will discuss in my talk the nature and extent of this digital divide, the ways in which it could be mitigated, and the benefits which would arise from the unification. I will base some of my discussion on my experiences in setting up a major programme to take the advantages of the internet revolution to hundreds of universities in India.

  10. Digital carbonate rock physics

    NASA Astrophysics Data System (ADS)

    Saenger, Erik H.; Vialle, Stephanie; Lebedev, Maxim; Uribe, David; Osorno, Maria; Duda, Mandy; Steeb, Holger

    2016-08-01

    Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions in the µm range for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study which we complement with nanoindentation experiments (for local elastic properties). In a first step a non-local mean filter is applied to the raw image data. We then apply different thresholds to identify pores and solid phases. Because of a non-neglectable amount of unresolved microporosity (micritic phase) we also define intermediate threshold values for distinct phases. Based on this segmentation we determine porosity-dependent values for effective P- and S-wave velocities as well as for the intrinsic permeability. For effective velocities we confirm an observed two-phase trend reported in another study using a different carbonate data set. As an upscaling approach we use this two-phase trend as an effective medium approach to estimate the porosity-dependent elastic properties of the micritic phase for the low-resolution images. The porosity measured in the laboratory is then used to predict the effective rock properties from the observed trends for a comparison with experimental data. The two-phase trend can be regarded as an upper bound for elastic properties; the use of the two-phase trend for low-resolution images led to a good estimate for a lower bound of effective elastic properties. Anisotropy is observed for some of the considered subvolumes, but seems to be insignificant for the analysed rocks at the DRP scale. Because of the complexity of carbonates we suggest using DRP as a complementary tool for rock characterization in addition to classical experimental methods.

  11. Digital cartography of Io

    NASA Technical Reports Server (NTRS)

    Mcewen, Alfred S.; Duck, B.; Edwards, Kathleen

    1991-01-01

    A high resolution controlled mosaic of the hemisphere of Io centered on longitude 310 degrees is produced. Digital cartographic techniques were employed. Approximately 80 Voyager 1 clear and blue filter frames were utilized. This mosaic was merged with low-resolution color images. This dataset is compared to the geologic map of this region. Passage of the Voyager spacecraft through the Io plasma torus during acquisition of the highest resolution images exposed the vidicon detectors to ionized radiation, resulting in dark-current buildup on the vidicon. Because the vidicon is scanned from top to bottom, more charge accumulated toward the bottom of the frames, and the additive error increases from top to bottom as a ramp function. This ramp function was removed by using a model. Photometric normalizations were applied using the Minnaert function. An attempt to use Hapke's photometric function revealed that this function does not adequately describe Io's limb darkening at emission angles greater than 80 degrees. In contrast, the Minnaert function accurately describes the limb darkening up to emission angles of about 89 degrees. The improved set of discrete camera angles derived from this effort will be used in conjunction with the space telemetry pointing history file (the IPPS file), corrected on 4 or 12 second intervals to derive a revised time history for the pointing of the Infrared Interferometric Spectrometer (IRIS). For IRIS observations acquired between camera shutterings, the IPPS file can be corrected by linear interpolation, provided that the spacecraft motions were continuous. Image areas corresponding to the fields of view of IRIS spectra acquired between camera shutterings will be extracted from the mosaic to place the IRIS observations and hotspot models into geologic context.

  12. Digital imaging and video: principles and applications.

    PubMed

    Rosen, Andrew L; Hausman, Michael

    2003-01-01

    Digital imaging has provided orthopaedic surgeons with new, powerful tools that offer a multitude of applications. Already integral to several common medical devices, digital images can be used for case documentation and presentation as well as for diagnostic and surgical patient care information. Educational presentation has been transformed by the use of computers and digital projectors. Understanding the basic foundations of digital imaging technology is important for effectively creating digital images, videos, and presentations.

  13. Generalized phase-shifting color digital holography

    NASA Astrophysics Data System (ADS)

    Nomura, Takanori; Kawakami, Takaaki; Shinomura, Kazuma

    2016-06-01

    Two methods to apply the generalized phase-shifting digital holography to color digital holography are proposed. One is wave-splitting generalized phase-shifting color digital holography. This is realized by using a color Bayer camera. Another is multiple exposure generalized phase-shifting color digital holography. This is realized by the wavelength-dependent phase-shifting devices. Experimental results for both generalized phase-shifting color digital holography are presented to confirm the proposed methods.

  14. Image processing techniques for digital orthophotoquad production

    USGS Publications Warehouse

    Hood, Joy J.; Ladner, L. J.; Champion, Richard A.

    1989-01-01

    Orthophotographs have long been recognized for their value as supplements or alternatives to standard maps. Recent trends towards digital cartography have resulted in efforts by the US Geological Survey to develop a digital orthophotoquad production system. Digital image files were created by scanning color infrared photographs on a microdensitometer. Rectification techniques were applied to remove tile and relief displacement, thereby creating digital orthophotos. Image mosaicking software was then used to join the rectified images, producing digital orthophotos in quadrangle format.

  15. Digital Health Services and Digital Identity in Alberta.

    PubMed

    McEachern, Aiden; Cholewa, David

    2017-01-01

    The Government of Alberta continues to improve delivery of healthcare by allowing Albertans to access their health information online. Alberta is the only province in Canada with provincial electronic health records for all its citizens. These records are currently made available to medical practitioners, but Alberta Health believes that providing Albertans access to their health records will transform the delivery of healthcare in Alberta. It is important to have a high level of assurance that the health records are provided to the correct Albertan. Alberta Health requires a way for Albertans to obtain a digital identity with a high level of identity assurance prior to releasing health records via the Personal Health Portal. Service Alberta developed the MyAlberta Digital ID program to provide a digital identity verification service. The Ministry of Health is leveraging MyAlberta Digital ID to enable Albertans to access their personal health records through the Personal Health Portal. The Government of Alberta is advancing its vision of patient-centred healthcare by enabling Albertans to access a trusted source for health information and their electronic health records using a secure digital identity.

  16. High Rate Digital Demodulator ASIC

    NASA Technical Reports Server (NTRS)

    Ghuman, Parminder; Sheikh, Salman; Koubek, Steve; Hoy, Scott; Gray, Andrew

    1998-01-01

    The architecture of High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation in other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA's Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an over-view of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver.

  17. Artifacts in digital coincidence timing

    DOE PAGES

    Moses, W. W.; Peng, Q.

    2014-10-16

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into amore » time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator.All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the 'optimal' method. In conclusion, the purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization.« less

  18. Digital health care: cementing centralisation?

    PubMed

    Keen, Justin

    2014-09-01

    This article reviews large-scale digital developments in the National Health Service in England in recent years and argues that there is a mismatch between digital and organisational thinking and practice. The arguments are based on new institutional thinking, where the digital infrastructure is taken to be an institution, which has been shaped over a long period, and which in turn shapes the behaviour of health professionals, managers and others. Many digital services are still being designed in line with a bureaucratic data processing model. Yet health services are increasingly based on a network model, where health professionals and service managers require information systems that allow them to manage risks proactively and to coordinate multiple services on behalf of patients. This article further argues that the data processing model is being reinforced by Open Data policies and by related developments in the acquisition of genomic and telehealth data, suggesting that the mismatch will persist. There is, therefore, an ongoing tension between frontline and central objectives for digital services. It may be that the tension can only be resolved when--or if--there is trust between the interested parties.

  19. REGISTRATION OF ORTHODONTIC DIGITAL MODELS

    PubMed Central

    Grauer, Dan; Cevidanes, Lucia H.; Tyndall, Donald; Styner, Martin A.; Flood, Patrick M.; Proffit, William R.

    2011-01-01

    Current methods to assess outcomes and change in orthodontics are comparison of photographs, cephalometric measurements and superimpositions, and comparisons/measurements on dental casts. Digital models are a relatively new records modality in orthodontics. They offer numerous advantages in terms of storage space, spatial registration and superimposition. The purpose of this chapter is to determine the reproducibility of: 1) establishing occlusion of independently scanned digital models; and 2) registering digital models obtained after treatment on their homologous digital model setups produced before treatment. Reliability of both procedures was assessed with two random samples of five patient’s models. In both experiments, three replicate positionings of the models per patient were created and variability in position was evaluated by the maximum surface difference between replicates, and the standard deviation of the surface distances between replicates respectively. Based on the data obtained, we concluded that it is reliable to register independently scanned models to a scanned surface of the models in occlusion. Surface-to-surface registration of final orthodontic digital models to planned setup models also is reproducible. PMID:26549917

  20. Digital X-Ray Imaging

    NASA Astrophysics Data System (ADS)

    Dance, David R.

    The use of X-ray image receptors that produce a digital image is becoming increasingly important. Possible benefits include improved dynamic range and detective quantum efficiency, improved detectability for objects of low intrinsic contrast, and reduced radiation dose. The image can be available quickly. The display is separated from the image capture so that processing and contrast adjustment are possible before the image is viewed. The availability of a digital image means ready input into PACS and opens up the possibility of computer-aided detection and classification of abnormality. Possible drawbacks of digital systems include high cost, limited high contrast resolution and the fact that their clinical value is sometimes not proven in comparison with conventional, analogue techniques. The high contrast resolution attainable with such systems is discussed and the problem of sampling limitations and aliasing considered. The properties and limitations of digital systems using computed radiography, caesium iodide plus CCDs and active matrix arrays with either caesium iodide or selenium detectors are demonstrated. Examples are given of digital systems for mammography and general radiography and their performance is demonstrated in terms of clinical assessment and measurements of the modulation transfer function and detective quantum efficiency.

  1. Machine vision for digital microfluidics.

    PubMed

    Shin, Yong-Jun; Lee, Jeong-Bong

    2010-01-01

    Machine vision is widely used in an industrial environment today. It can perform various tasks, such as inspecting and controlling production processes, that may require humanlike intelligence. The importance of imaging technology for biological research or medical diagnosis is greater than ever. For example, fluorescent reporter imaging enables scientists to study the dynamics of gene networks with high spatial and temporal resolution. Such high-throughput imaging is increasingly demanding the use of machine vision for real-time analysis and control. Digital microfluidics is a relatively new technology with expectations of becoming a true lab-on-a-chip platform. Utilizing digital microfluidics, only small amounts of biological samples are required and the experimental procedures can be automatically controlled. There is a strong need for the development of a digital microfluidics system integrated with machine vision for innovative biological research today. In this paper, we show how machine vision can be applied to digital microfluidics by demonstrating two applications: machine vision-based measurement of the kinetics of biomolecular interactions and machine vision-based droplet motion control. It is expected that digital microfluidics-based machine vision system will add intelligence and automation to high-throughput biological imaging in the future.

  2. Components of dynamic digital maps

    NASA Astrophysics Data System (ADS)

    Condit, Christopher D.

    1999-05-01

    The core of a dynamic digital map (DDM) is a program created to display a digital geologic map and its associated data set as a single integrated package. This DDM program core is authored using a high-level object oriented graphical programming environment, SuperCard, a Macintosh `xTalk' language. Some of the major philosophical underpinnings relevant to the job of creating DDMs in this programming environment include taking advantage of specific object's attributes, how to organize data structure effectively for this job and keeping applicable code as transportable (generalized) as possible between objects. The core components of DDMs are parts of a SuperCard `template' or map display `container' into which the various externally created digital pieces (e.g. CAD produced geologic maps, spread sheet data, digital images, text files, movies) can be inserted for integrated display and digital publication. Components of DDMs consist of windows, cards within these windows, card fields (text and data containers) and a menu structure. The paper discusses each of these major components and how they fit into a DDM and gives examples of each topic in programs whose components demonstrate the concept. These programs are available from Web (see Appendix A); readers can refer to them as they examine these examples.

  3. The digital eczema centre utrecht.

    PubMed

    van Os-Medendorp, Harmieke; van Veelen, Carien; Hover, Maaike; Eland-de Kok, Petra; Bruijnzeel-Koomen, Carla; Sonnevelt, Gert-Jan; Mensing, Geert; Pasmans, Suzanne

    2010-01-01

    The University Medical Centre Utrecht (UMC Utrecht) has developed an eczema portal that combines e-consulting, monitoring and self-management training by a dermatology nurse online for patients and parents of young children with atopic dermatitis (AD). Patient satisfaction with the portal was high. It could be extended to become a Digital Eczema Centre for multidisciplinary collaboration between health-care providers from different locations and the patient. Before starting the construction of the Digital Eczema Centre, the feasibility was examined by carrying out a business case analysis. The purposes, strength and weaknesses showed that the Digital Eczema Centre offered opportunities to improve care for patients with AD. The financial analysis resulted in a medium/best case scenario with a positive result of euro50-240,000 over a period of five years. We expect that the Digital Eczema Centre will increase the accessibility and quality of care. The web-based patient record and the digital chain-of-care promote the involvement of patients, parents and multidisciplinary teams as well as the continuity and coordination of care.

  4. BCIS digital data link as part of the digitized battlefield

    NASA Astrophysics Data System (ADS)

    Haynesworth, Linnie M.

    1996-06-01

    As proven in Desert Storm, the confusion of a rapidly moving air-land battle involving multinational forces is a situational awareness (SA) nightmare. Current methods of communication require traversing layers of networking or searching for frequencies to reach users in different outfits, which is time consuming and frustrating. The digital data link increases realtime SA in the digitized battlefield by providing mechanized platoons with a wireless horizontal local area network SA data passing capability. This increased real-time SA data acts both as a force multiplier and helps reduce the incidence of fratricide.

  5. Apparatus and method for managing digital resources by passing digital resource tokens between queues

    DOEpatents

    Crawford, Henry J.; Lindenstruth, Volker

    1999-01-01

    A method of managing digital resources of a digital system includes the step of reserving token values for certain digital resources in the digital system. A selected token value in a free-buffer-queue is then matched to an incoming digital resource request. The selected token value is then moved to a valid-request-queue. The selected token is subsequently removed from the valid-request-queue to allow a digital agent in the digital system to process the incoming digital resource request associated with the selected token. Thereafter, the selected token is returned to the free-buffer-queue.

  6. Apparatus and method for managing digital resources by passing digital resource tokens between queues

    DOEpatents

    Crawford, H.J.; Lindenstruth, V.

    1999-06-29

    A method of managing digital resources of a digital system includes the step of reserving token values for certain digital resources in the digital system. A selected token value in a free-buffer-queue is then matched to an incoming digital resource request. The selected token value is then moved to a valid-request-queue. The selected token is subsequently removed from the valid-request-queue to allow a digital agent in the digital system to process the incoming digital resource request associated with the selected token. Thereafter, the selected token is returned to the free-buffer-queue. 6 figs.

  7. Advanced digital SAR processing study

    NASA Technical Reports Server (NTRS)

    Martinson, L. W.; Gaffney, B. P.; Liu, B.; Perry, R. P.; Ruvin, A.

    1982-01-01

    A highly programmable, land based, real time synthetic aperture radar (SAR) processor requiring a processed pixel rate of 2.75 MHz or more in a four look system was designed. Variations in range and azimuth compression, number of looks, range swath, range migration and SR mode were specified. Alternative range and azimuth processing algorithms were examined in conjunction with projected integrated circuit, digital architecture, and software technologies. The advaced digital SAR processor (ADSP) employs an FFT convolver algorithm for both range and azimuth processing in a parallel architecture configuration. Algorithm performace comparisons, design system design, implementation tradeoffs and the results of a supporting survey of integrated circuit and digital architecture technologies are reported. Cost tradeoffs and projections with alternate implementation plans are presented.

  8. Digitally controlled distributed phase shifter

    SciTech Connect

    Hietala, V.M.; Kravitz, S.H.; Vawter, G.A.

    1992-12-31

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one of two discrete bias voltages. The application of the discrete bias voltages change the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  9. Astronomy in the Digital Universe

    NASA Astrophysics Data System (ADS)

    Haisch, Bernard M.; Lindblom, J.; Terzian, Y.

    2006-12-01

    The Digital Universe is an Internet project whose mission is to provide free, accurate, unbiased information covering all aspects of human knowledge, and to inspire humans to learn, make use of, and expand this knowledge. It is planned to be a decades long effort, inspired by the Encyclopedia Galactica concept popularized by Carl Sagan, and is being developed by the non-profit Digital Universe Foundation. A worldwide network of experts is responsible for selecting content featured within the Digital Universe. The first publicly available content is the Encyclopedia of Earth, a Boston University project headed by Prof. Cutler Cleveland, which will be part of the Earth Portal. The second major content area will be an analogous Encyclopedia of the Cosmos to be part of the Cosmos Portal. It is anticipated that this will evolve into a major resource for astronomy education. Authors and topic editors are now being recruited for the Encyclopedia of the Cosmos.

  10. Mesofluidic two stage digital valve

    DOEpatents

    Jansen, John F; Love, Lonnie J; Lind, Randall F; Richardson, Bradley S

    2013-12-31

    A mesofluidic scale digital valve system includes a first mesofluidic scale valve having a valve body including a bore, wherein the valve body is configured to cooperate with a solenoid disposed substantially adjacent to the valve body to translate a poppet carried within the bore. The mesofluidic scale digital valve system also includes a second mesofluidic scale valve disposed substantially perpendicular to the first mesofluidic scale valve. The mesofluidic scale digital valve system further includes a control element in communication with the solenoid, wherein the control element is configured to maintain the solenoid in an energized state for a fixed period of time to provide a desired flow rate through an orifice of the second mesofluidic valve.

  11. Digital slide reproduction using densitometry

    NASA Astrophysics Data System (ADS)

    Fornaro, Peter R.; Gschwind, Rudolf; Rosenthaler, Lukas; Laurenson, Pip

    2002-06-01

    Many contemporary art collections contain important art installations where artists have used 35 mm slides as the primary medium. The number of ours these works are on show makes it necessary to regularly change the slides due to light fading. With funding from the Henry Moore Foundation. The conservation department at Tate initiated a project to examine ways in which digital technology could be used to aid the conservation of these works. The aim of the project was to place the original slides in cold storage and explored the possibility of using digital technology to make duplicate sets for display in the gallery. The reproductions needed to be of very high quality both in terms of resolution and color management. This paper discusses the use of densitometry to calibrate both device dependent and device independent systems for digitally reproducing 35 mm slides using a scanner and a film recorder and the effect of metamery when using slide films which employ different dyes.

  12. Digital logic testing and testability

    NASA Astrophysics Data System (ADS)

    Debany, Warren H., Jr.

    1991-02-01

    Electronic hardware is subject to defects that are introduced at the time of manufacture and failures that occur in the field. Because of the complexity of digital logic circuits, they are difficult to test. This report provides an overview of digital logic testing. It provides access to the literature and unifies terminology and concepts that have evolved in this field. It discusses the types and causes of failures in digital logic. This report presents the topics of logic and fault simulation, fault grading, test generation algorithms, and fault isolation. The discussion of testability measurement is useful for understanding testability requirements and analysis techniques. Design-for-testability and built in test techniques are presented.

  13. Digitally controlled distributed phase shifter

    DOEpatents

    Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

    1993-01-01

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  14. Digitally controlled distributed phase shifter

    DOEpatents

    Hietala, V.M.; Kravitz, S.H.; Vawter, G.A.

    1993-08-17

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one or two discrete bias voltages. The application of the discrete bias voltages changes the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  15. Precision digital pulse phase generator

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code.

  16. Precision digital pulse phase generator

    DOEpatents

    McEwan, T.E.

    1996-10-08

    A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code. 2 figs.

  17. Digital circuits for computer applications: A compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The innovations in this updated series of compilations dealing with electronic technology represent a carefully selected collection of digital circuits which have direct application in computer oriented systems. In general, the circuits have been selected as representative items of each section and have been included on their merits of having universal applications in digital computers and digital data processing systems. As such, they should have wide appeal to the professional engineer and scientist who encounter the fundamentals of digital techniques in their daily activities. The circuits are grouped as digital logic circuits, analog to digital converters, and counters and shift registers.

  18. Programmable Analog-To-Digital Converter

    NASA Technical Reports Server (NTRS)

    Kist, Edward H., Jr.

    1993-01-01

    High-speed analog-to-digital converter with programmable voltage steps that can be changed during operation. Allows concentration of converter resolution over specific portion of waveform. Particularly useful in digitizing wind-shear radar and lidar return signals, in digital oscilloscopes, and other applications in which desirable to increase digital resolution over specific area of waveform while accepting lower resolution over rest of waveform. Effective increase in dynamic range achieved without increase in number of analog-to-digital converter bits. Enabling faster analog-to-digital conversion.

  19. All-digital radar architecture

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo A.

    2014-10-01

    All digital radar architecture requires exclude mechanical scan system. The phase antenna array is necessarily large because the array elements must be co-located with very precise dimensions and will need high accuracy phase processing system for aggregate and distribute T/R modules data to/from antenna elements. Even phase array cannot provide wide field of view. New nature inspired all digital radar architecture proposed. The fly's eye consists of multiple angularly spaced sensors giving the fly simultaneously thee wide-area visual coverage it needs to detect and avoid the threats around him. Fly eye radar antenna array consist multiple directional antennas loose distributed along perimeter of ground vehicle or aircraft and coupled with receiving/transmitting front end modules connected by digital interface to central processor. Non-steering antenna array allows creating all-digital radar with extreme flexible architecture. Fly eye radar architecture provides wide possibility of digital modulation and different waveform generation. Simultaneous correlation and integration of thousands signals per second from each point of surveillance area allows not only detecting of low level signals ((low profile targets), but help to recognize and classify signals (targets) by using diversity signals, polarization modulation and intelligent processing. Proposed all digital radar architecture with distributed directional antenna array can provide a 3D space vector to the jammer by verification direction of arrival for signals sources and as result jam/spoof protection not only for radar systems, but for communication systems and any navigation constellation system, for both encrypted or unencrypted signals, for not limited number or close positioned jammers.

  20. Creating a digital medical illustration.

    PubMed

    Culley, Joanna

    2016-01-01

    This paper covers the steps required to complete a medical illustration in a digital format using Adobe Illustrator and Photoshop. The project example is the surgical procedure for the release of the glenohumeral joint for the condition known as 'frozen shoulder'. The purpose is to demonstrate one method which an artist can use within digital media to create a colour illustration such as the release of the glenohumeral joint. Included is a general overview as how to deal with the administration of a medical illustration commission through the experience of a professional freelance artist.

  1. Advanced simulation of digital filters

    NASA Astrophysics Data System (ADS)

    Doyle, G. S.

    1980-09-01

    An Advanced Simulation of Digital Filters has been implemented on the IBM 360/67 computer utilizing Tektronix hardware and software. The program package is appropriate for use by persons beginning their study of digital signal processing or for filter analysis. The ASDF programs provide the user with an interactive method by which filter pole and zero locations can be manipulated. Graphical output on both the Tektronix graphics screen and the Versatec plotter are provided to observe the effects of pole-zero movement.

  2. Flight Trainer Digital Computer Study

    DTIC Science & Technology

    1951-03-21

    digital I*? computation. By programming, is: meant the process of breaMhg down ail complex algebraic formulae» and numerical iiategnatioli formulae...instructiveTir~sTtö~ enumerate. the^r^heiföt^Fop^tipis" which constitute the computation, and solution of the ERCO, equations. From tie algebraic .point of view...pösTte routines •Ehe algebraic notion of ^operation^cpmpl’exity is aliiiost immediate- ly applicable ,t,o digital computation. On. the other’ hand

  3. Digital control of HVDC converters

    SciTech Connect

    Pilotto, L.A.S.; Roitman, M.; Alves, J.E.R.

    1989-05-01

    This paper presents the project of a completely digital HVDC converter controller based on a 16-bit microcomputer. It was decided to achieve as much as possible by software in order to minimize functions performed by external hardware. The presented design comprises software programmed functions such as a PID current control amplifier, voltage dependent current order limiters and an alpha-minimum symmetrization unit, among others. HVDC control principles are briefly reviewed and a detailed description of both the hardware and software structure of the controller is presented. The digital controller was implemented in an HVDC simulator and several dynamic performance tests demonstrated the efficiency of the proposed methodology.

  4. Digital laser scanning fundus camera.

    PubMed

    Plesch, A; Klingbeil, U; Bille, J

    1987-04-15

    Imaging and documentation of the human retina for clinical diagnostics are conventionally achieved by classical optical methods. We designed a digital laser scanning fundus camera. The optoelectronical instrument is based on scanning laser illumination of the retina and a modified video imaging procedure. It is coupled to a digital image buffer and a microcomputer for image storage and processing. Aside from its high sensitivity the LSF incorporates new ophthalmic imaging methods like polarization differential contrast. We give design considerations as well as a description of the instrument and its performance.

  5. Digital Doppler measurement with spacecraft

    NASA Technical Reports Server (NTRS)

    Kinman, Peter W.; Hinedi, Sami M.; Labelle, Remi C.; Bevan, Roland P.; Del Castillo, Hector M.; Chong, Dwayne C.

    1991-01-01

    Digital and analog phase-locked loop (PLL) receivers were operated in parallel, each tracking the residual carrier from a spacecraft. The PLL tracked the downlink carrier and measured its instantaneous phase. This information, combined with a knowledge of the uplink carrier and the transponder ratio, permitted the computation of a Doppler observable. In this way, two separate Doppler measurements were obtained for one observation window. The two receivers agreed on the magnitude of the Doppler effect to within 1 mHz. There was less jitter on the data from the digital receiver. This was due to its smaller noise bandwidth. The demonstration and its results are described.

  6. Digital video delivery for a digital library in computer science

    NASA Astrophysics Data System (ADS)

    Fox, Edward A.; Abdulla, Ghaleb

    1994-04-01

    With support from four NSF awards we aim to develop a prototype digital library in computer science and apply it to improve undergraduate educations. First, Project Envision, `A User- Centered Database from the Computer Science Literature,' 1991-94, deals with translation, coding standards including SGML, retrieval/previewing/presentation/browsing/linking, human-computer interaction, and construction of a partial archive using text and multimedia materials provided by ACM. Second, `Interactive Learning with a Digital Library in Computer Science,' 1993-96, supported by NSF and ACM with additional assistance from other publishers, focuses on improving learning through delivery of materials from the archive. Third, `Networked Multimedia File System with HyTime,' funded by NSF through the SUCCEED coalition, considers networking support for distributed multimedia applications and the use of HyTime for description of such applications. Fourth, equipment support comes from the Information Access Laboratory allotment of the `Interactive Accessibility: Breaking Barriers to the Power of Computing' grant funded by NSF for 1993-98. In this paper we report on plans and work with digital video relating to these projects. In particular we focus on our analysis of the requirements for a multimedia digital library in computer science and our experience with MPEG as it applies to that library.

  7. Digital Education: Opportunities for Social Collaboration. Digital Education and Learning

    ERIC Educational Resources Information Center

    Thomas, Michael, Ed.

    2011-01-01

    This timely collection of theoretical and applied studies examines the pedagogical potential and realities of digital technologies in a wide range of disciplinary contexts across the educational spectrum. By mixing content-based chapters with a theoretical perspective with case studies detailing actual teaching approaches utilizing digital…

  8. Digital systems design language. Design synthesis of digital systems

    NASA Technical Reports Server (NTRS)

    Shiva, S. G.

    1979-01-01

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

  9. Digital audio and video broadcasting by satellite

    NASA Astrophysics Data System (ADS)

    Yoshino, Takehiko

    In parallel with the progress of the practical use of satellite broadcasting and Hi-Vision or high-definition television technologies, research activities are also in progress to replace the conventional analog broadcasting services with a digital version. What we call 'digitalization' is not a mere technical matter but an important subject which will help promote multichannel or multimedia applications and, accordingly, can change the old concept of mass media, such as television or radio. NHK Science and Technical Research Laboratories has promoted studies of digital bandwidth compression, transmission, and application techniques. The following topics are covered: the trend of digital broadcasting; features of Integrated Services Digital Broadcasting (ISDB); compression encoding and transmission; transmission bit rate in 12 GHz band; number of digital TV transmission channels; multichannel pulse code modulation (PCM) audio broadcasting system via communication satellite; digital Hi-Vision broadcasting; and development of digital audio broadcasting (DAB) for mobile reception in Japan.

  10. Digital Audio Application to Short Wave Broadcasting

    NASA Technical Reports Server (NTRS)

    Chen, Edward Y.

    1997-01-01

    Digital audio is becoming prevalent not only in consumer electornics, but also in different broadcasting media. Terrestrial analog audio broadcasting in the AM and FM bands will be eventually be replaced by digital systems.

  11. Optical Digital Disks as Mass Storage Media.

    ERIC Educational Resources Information Center

    Boss, Richard W.

    1983-01-01

    Describes the optical digital disk, which stores machine-readable information in digitized form, and discusses their production, cost, present and future applications. The major companies currently active in the disk field are noted. (MBR)

  12. Digital Video Over Space Systems and Networks

    NASA Technical Reports Server (NTRS)

    Grubbs, Rodney

    2010-01-01

    This slide presentation reviews the improvements and challenges that digital video provides over analog video. The use of digital video over IP options and trade offs, link integrity and latency are reviewed.

  13. A study of digital holographic filter generation

    NASA Technical Reports Server (NTRS)

    Calhoun, M.; Ingels, F.

    1976-01-01

    Problems associated with digital computer generation of holograms are discussed along with a criteria for producing optimum digital holograms. This criteria revolves around amplitude resolution and spatial frequency limitations induced by the computer and plotter process.

  14. Using Digital Photography to Enhance Student Creativity

    ERIC Educational Resources Information Center

    Siegle, Del

    2012-01-01

    The purpose of this article is to help students develop their digital photography skills and see the world through new eyes. An emphasis is placed on using digital photography to communicate ideas and feelings. (Contains 6 figures and 2 tables.)

  15. Black Men and the Digital Divide

    ERIC Educational Resources Information Center

    Conceição, Simone C. O.; Martin, Larry G.

    2016-01-01

    This chapter focuses on the role adult educators can play in assisting Black men to overcome the challenges faced in accessing and using digital technology and acquiring appropriate skills in a digital society.

  16. Scientific Archives in the Age of Digitization.

    PubMed

    Ogilvie, Brian

    2016-03-01

    Historians are increasingly working with material that is not only digital but has been digitized. Early digitization projects aimed to encode data for systematic analysis; more recent projects have sought to reproduce unique archival material in a manner that allows for open-ended historical inquiry without the need to travel to archives and manipulate physical objects. Such projects have undeniable benefits for the preservation of documents and access to them. Yet historians must be aware of the scope of digitization, the reasons why material is chosen to be digitized, and limitations on the dissemination of digitized sources. Furthermore, some physical aspects of sources, and of collections of sources, are lost in their digital simulacra. Nonetheless, digitization and the standardization of metadata offer significant possibilities for future archival research and documentation.

  17. The Security Research of Digital Library Network

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Song, Ding-Li; Yan, Shu

    Digital library is a self-development needs for the modern library to meet the development requirements of the times, changing the way services and so on. digital library from the hardware, technology, management and other aspects to objective analysis of the factors of threats to digital library network security. We should face up the problems of digital library network security: digital library network hardware are "not hard", the technology of digital library is relatively lag, digital library management system is imperfect and other problems; the government should take active measures to ensure that the library funding, to enhance the level of network hardware, to upgrade LAN and prevention technology, to improve network control technology, network monitoring technology; to strengthen safety management concepts, to prefect the safety management system; and to improve the level of security management modernization for digital library.

  18. Digital Learning for All. Now

    ERIC Educational Resources Information Center

    Costa, Jonathan P., Sr.

    2012-01-01

    The evidence is undeniable and abundant: the future of learning and work is digital. Yet despite the possibilities, progress toward a truly 21st century learning environment is painfully lacking: the printed page still forms the foundation of learning for most students. How can public schools meet the challenges of the modern learner when they are…

  19. Digital Portfolios: Fact or Fashion?

    ERIC Educational Resources Information Center

    Woodward, Helen; Nanlohy, Phil

    2004-01-01

    The value of portfolios as an assessment tool is thoroughly researched and their use in education is well documented ( Woodward, 2000). Research on the introduction of digital portfolios is substantially based on general portfolio research; however, additional specific factors and features need to be considered. One of the inherent dangers with…

  20. Stop Calling It "Digital Humanities"

    ERIC Educational Resources Information Center

    Pannapacker, William

    2013-01-01

    A persistent criticism of the digital-humanities movement is that it is elitist and exclusive because it requires the resources of a major university (faculty, infrastructure, money), and is thus more suited to campuses with a research focus. Academics and administrators at small liberal-arts colleges may read about DH and, however exciting it…

  1. Getting Past the "Digital Divide"

    ERIC Educational Resources Information Center

    McCollum, Sean

    2011-01-01

    As most educators know, there is a lot more to addressing the so-called "digital divide" than having enough working machines in classrooms. Effective information technology (IT) in schools requires useful software, reliable and speedy Internet access, effective teacher training, and well-considered goals with transformative outcomes. Educators who…

  2. Make Your Own Digital Thermometer!

    ERIC Educational Resources Information Center

    Sorey, Timothy; Willard, Teri; Kim, Bom

    2010-01-01

    In the hands-on, guided-inquiry lesson presented in this article, high school students create, calibrate, and apply an affordable scientific-grade instrument (Lapp and Cyrus 2000). In just four class periods, they build a homemade integrated circuit (IC) digital thermometer, apply a math model to calibrate their instrument, and ask a researchable…

  3. Integrating Data across Digital Activities

    ERIC Educational Resources Information Center

    DiCerbo, Kristen

    2016-01-01

    The volume of data that can be captured and stored from students' everyday interactions with digital environments allows for the creation of models of student knowledge, skills, and attributes unobtrusively. However, models and techniques for transforming these data into information that is useful for educators have not been established. This…

  4. Digital Citizenship for Educational Change

    ERIC Educational Resources Information Center

    Ribble, Mike

    2012-01-01

    Students are coming to school with more and more exposure to digital tools, such as smartphones, tablets, and social networking apps (Rideout, Foehr, and Roberts 2010). Though teachers are trying to "catch up" with their students, many were not provided instruction in these skills during their preservice training, and technology is only one among…

  5. Student Engagement through Digital Data

    ERIC Educational Resources Information Center

    Gross, Liz; Meriwether, Jason L.

    2016-01-01

    This chapter suggests strategies and tools for student affairs professionals to leverage digital data to measure student engagement and learning outcomes, and refine programs that enhance institutional reputation and improve student persistence. The construct of student engagement is traced from its theoretical origins to recent research…

  6. Eliminating ambiguity in digital signals

    NASA Technical Reports Server (NTRS)

    Weber, W. J., III

    1979-01-01

    Multiamplitude minimum shift keying (mamsk) transmission system, method of differential encoding overcomes problem of ambiguity associated with advanced digital-transmission techniques with little or no penalty in transmission rate, error rate, or system complexity. Principle of method states, if signal points are properly encoded and decoded, bits are detected correctly, regardless of phase ambiguities.

  7. Tweens' Characterization of Digital Technologies

    ERIC Educational Resources Information Center

    Brito, Pedro Quelhas

    2012-01-01

    The tweens are a transitional age group undergoing deep physical and psychological transformations. Based on a thirteen-focus group research design involving 103 students, and applying a tweens-centered approach, the characteristics of SMS, IM, Internet, digital photos, electronic games, and email were analyzed. Categories such as moral issues,…

  8. Digital Storytelling: Reinventing Literature Circles

    ERIC Educational Resources Information Center

    Tobin, Maryann Tatum

    2012-01-01

    New literacies in reading research demand the study of comprehension skills using multiple modalities through a more complex, multi-platform view of reading. Taking into account the robust roll of technology in our daily lives, this article presents an update to the traditional literature circle lesson to include digital storytelling and…

  9. Integrating Digital and STEM Practices

    ERIC Educational Resources Information Center

    White, Tobin; Martin, Lee

    2012-01-01

    As mobile devices become increasingly pervasive among youth, the gap between students with and without access to personal computers at home may soon be replaced by a new digital divide: between one set of informal ways of using those tools that are familiar, personally meaningful, and relevant to their out-of-school lives, and another set of uses…

  10. Digital Teachers Reshaping Literacy Experiences

    ERIC Educational Resources Information Center

    Ryan, Tammy

    2012-01-01

    When the National Reading Panel ([NRP] 2000) released its report challenging school districts to re-inspect then realign literacy programs according to "best practices," a digital literacy explosion was occurring--forever reshaping the literacy experiences students were having outside of school. Teachers began infusing curricular standards with…

  11. Dueling Digits: Fighting for Equivalency.

    ERIC Educational Resources Information Center

    Olds, Henry F. Jr

    1982-01-01

    Reviews "Dueling Digits," an arcade-style computer game, in which the player creates mathematical equations. Discusses features of the program, educational value, design quality, documentation, and ease of use. Tested on Apple II/Apple II-Plus, the program (requiring 48K, disk drive and game paddles/joystick) is rated as an excellent…

  12. High-speed digital plotter

    NASA Technical Reports Server (NTRS)

    Gray, J., Jr.

    1971-01-01

    Modified typewriter mechanism with standard logic components provides digital plot of output of multichannel analyzer. Unit plots irregular curves at approximately 14 channels per second, and smooth curves at over 25 channels per second, and is not subject to analog error or drift.

  13. Living in a Digital Age

    ERIC Educational Resources Information Center

    Vaira, Douglas

    2009-01-01

    Almost since the advent of the Internet, pundits have been suggesting that at some point people will completely abandon their paper-and-ink ways and migrate entirely to digital information sources and means of communication. But while traditional news sources such as newspapers and television still exist, it is becoming increasingly clear that…

  14. BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

    USGS Publications Warehouse

    Seeley, Robert L.; Daniels, Jeffrey J.

    1984-01-01

    A system has been developed to simultaneously sample and transmit digital data from five remote geophysical data receiver stations to a control station that processes, displays, and stores the data. A microprocessor in each remote station receives commands from the control station over a single telemetry channel.

  15. Approaching Academic Digital Content Management.

    ERIC Educational Resources Information Center

    Acker, Stephen R.

    2002-01-01

    Discusses digital content management in higher education. Highlights include learning objects that make content more modular so it can be used in other courses or by other institutions; and a system at Ohio State University for content management that includes the creation of learner profiles. (LRW)

  16. JCE Digital Library Grand Opening

    NASA Astrophysics Data System (ADS)

    JCE Editorial Staff

    2004-01-01

    The Journal of Chemical Education introduces the JCE Digital Library and its four collections: JCE SymMath: Symbolic Mathematics In Chemistry JCE WebWare: Web-based Learning Aids JCE QBank: Resources for Student Assessment JCE DigiDemos: Tested Demonstrations

  17. Overconfidence, Incentives and Digit Ratio

    PubMed Central

    Neyse, Levent; Bosworth, Steven; Ring, Patrick; Schmidt, Ulrich

    2016-01-01

    This paper contributes to a better understanding of the biological underpinnings of overconfidence by analyzing performance predictions in the Cognitive Reflection Test with and without monetary incentives. In line with the existing literature we find that the participants are too optimistic about their performance on average; incentives lead to higher performance; and males score higher than females on this particular task. The novelty of this paper is an analysis of the relation between participants’ performance prediction accuracy and their second to fourth digit ratio. It has been reported that the digit ratio is a negatively correlated bio-marker of prenatal testosterone exposure. In the un-incentivized treatment, we find that males with low digit ratios, on average, are significantly more overconfident about their performance. In the incentivized treatment, however, we observe that males with low digit ratios, on average, are less overconfident about their performance. These effects are not observed in females. We discuss how these findings fit into the literature on testosterone and decision making and how they might help to explain seemingly opposing evidence. PMID:27039893

  18. Can You DIG/IT?

    ERIC Educational Resources Information Center

    Nolan, Joy; Preston, Michael; Finkelstein, Jonathan

    2012-01-01

    New York City's Department of Education offers a course called Digital Literacies, in which overage and undercredited high school students in more than 60 schools develop key skills needed for life after high school, whether it entails further education, employment, or, more commonly, both. With a "blended learning" design, it is more…

  19. Managing and Evaluating Digital Repositories

    ERIC Educational Resources Information Center

    Zuccala, Alesia; Oppenheim, Charles; Dhiensa, Rajveen

    2008-01-01

    Introduction: We examine the role of the digital repository manager, discuss the future of repository management and evaluation and suggest that library and information science schools develop new repository management curricula. Method: Face-to-face interviews were carried out with managers of five different types of repositories and a Web-based…

  20. Digital Resilience in Higher Education

    ERIC Educational Resources Information Center

    Weller, Martin; Anderson, Terry

    2013-01-01

    Higher education institutions face a number of opportunities and challenges as the result of the digital revolution. The institutions perform a number of scholarship functions which can be affected by new technologies, and the desire is to retain these functions where appropriate, whilst the form they take may change. Much of the reaction to…

  1. Scribes of the Digital Era

    ERIC Educational Resources Information Center

    Young, Jeffrey R.

    2006-01-01

    A nonprofit organization known as Internet Archive is guiding a mass-digitization project called the Open Content Alliance that plans to take carefully selected collections of out-of-copyright books from libraries around the world and turn them into e-books that will be available free to anyone who wants to view, print or even download them to…

  2. Encryption and Digital Signature Standards

    DTIC Science & Technology

    2007-11-02

    4 3.2.5. Smart Card Token .......................................................................................... 4...3.2.6. Smart Card ..................................................................................................... 4 3.2.7. Digital Certificates...be intercepted, and that it follows the IPsec protocols. 3.2.5. Smart Card Token. A smart card token is a small electronic device that contains

  3. Digital Video: Get with It!

    ERIC Educational Resources Information Center

    Van Horn, Royal

    2001-01-01

    Several years after the first audiovisual Macintosh computer appeared, most educators are still oblivious of this technology. Almost every other economic sector (including the porn industry) makes abundant use of digital and streaming video. Desktop movie production is so easy that primary grade students can do it. Tips are provided. (MLH)

  4. Digital Telematics: Present and Future.

    ERIC Educational Resources Information Center

    Stalberg, Christian E.

    1987-01-01

    This overview of developments in international telecommunications networks focuses on their importance for developing countries and the necessary interdependence of all countries. Highlights include digital technology, telephone service, packet switching networks, communications satellites, fiber optic cables, and possible future developments.…

  5. Customizing Curriculum with Digital Resources

    ERIC Educational Resources Information Center

    Miller, Jeffrey

    2011-01-01

    To effectively use digital resources in the classroom, teachers must customize the information, merge it with pre-existing curriculum, differentiate it for diverse student populations, and still meet standards-based learning goals. This article describes a solution to these challenges: the Curriculum Customization Service, which provides access to…

  6. Digital Citizenship Policy Development Guide

    ERIC Educational Resources Information Center

    Alberta Education, 2012

    2012-01-01

    Education leaders are re-examining acceptable use policies in light of the increasing use of highly mobile information technologies. While acceptable use policies were developed to manage and control behaviour, a digital citizenship policy takes a more comprehensive approach by recognizing the important role of education in preparing digital…

  7. Digital Citizenship within Global Contexts

    ERIC Educational Resources Information Center

    Searson, Michael; Hancock, Marsali; Soheil, Nusrat; Shepherd, Gregory

    2015-01-01

    EduSummIT 2013 featured a working group that examined digital citizenship within a global context. Group members recognized that, given today's international, regional, political, and social dynamics, the notion of "global" might be more aspirational than practical. The development of informed policies and practices serving and involving…

  8. Plasma digital density determining device

    DOEpatents

    Sprott, Julien C.; Lovell, Thomas W.; Holly, Donald J.

    1976-01-01

    The density of a decaying plasma in an electrically conducting enclosure is determined by applying an excitation to the cavity formed by the enclosure and counting digitally the number of resonant frequencies traversed by the combination of the cavity and the decaying plasma.

  9. Empowering Students with Digital Reading

    ERIC Educational Resources Information Center

    Puente, Kelly

    2012-01-01

    This article describes new digital reading products that are designed to improve aptitude, fulfill Common Core State Standards, provide unlimited access to online libraries, and bring 21st-century learning into the classroom. With a coming wave of the new products, school districts have various options to help bring 21st-century learning into the…

  10. Digital design using selection operations

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    A digital integrated circuit chip is designed by identifying a logical structure to be implemented. This logical structure is represented in terms of a logical operations, at least 5% of which include selection operations. A determination is made of logic cells that correspond to an implementation of these logical operations.

  11. Getting Past the "Digital Divide"

    ERIC Educational Resources Information Center

    McCollum, Sean

    2011-01-01

    In the last decade, "digital divide" has become a catchphrase for the stubborn disparity in IT resources between communities, especially in regard to education. Low-income, rural and minority populations have received special scrutiny as the technological "have-nots." This article presents success stories of educators who can work around obstacles…

  12. Video Games and Digital Literacies

    ERIC Educational Resources Information Center

    Steinkuehler, Constance

    2010-01-01

    Today's youth are situated in a complex information ecology that includes video games and print texts. At the basic level, video game play itself is a form of digital literacy practice. If we widen our focus from the "individual player + technology" to the online communities that play them, we find that video games also lie at the nexus of a…

  13. Customizable Digital Receivers for Radar

    NASA Technical Reports Server (NTRS)

    Moller, Delwyn; Heavey, Brandon; Sadowy, Gregory

    2008-01-01

    Compact, highly customizable digital receivers are being developed for the system described in 'Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets' (NPO-43962), NASA Tech Briefs, Vol. 31, No. 7 (August 2007), page 72. The receivers are required to operate in unison, sampling radar returns received by the antenna elements in a digital beam-forming (DBF) mode. The design of these receivers could also be adapted to commercial radar systems. At the time of reporting the information for this article, there were no commercially available digital receivers capable of satisfying all of the operational requirements and compact enough to be mounted directly on the antenna elements. A provided figure depicts the overall system of which the digital receivers are parts. Each digital receiver includes an analog-to-digital converter (ADC), a demultiplexer (DMUX), and a field-programmable gate array (FPGA). The ADC effects 10-bit band-pass sampling of input signals having frequencies up to 3.5 GHz. The input samples are demultiplexed at a user-selectable rate of 1:2 or 1:4, then buffered in part of the FPGA that functions as a first-in/first-out (FIFO) memory. Another part of the FPGA serves as a controller for the ADC, DMUX, and FIFO memory and as an interface between (1) the rest of the receiver and (2) a front-panel data port (FPDP) bus, which is an industry-standard parallel data bus that has a high data-rate capability and multichannel configuration suitable for DBF. Still other parts of the FPGA in each receiver perform signal-processing functions. The digital receivers can be configured to operate in a stand-alone mode, or in a multichannel mode as needed for DBF. The customizability of the receiver makes it applicable to a broad range of system architectures. The capability for operation of receivers in either a stand-alone or a DBF mode enables the use of the receivers in an unprecedentedly wide variety of radar systems.

  14. Prophylactic digitalization for coronary artery bypass surgery.

    PubMed

    Johnson, L W; Dickstein, R A; Fruehan, C T; Kane, P; Potts, J L; Smulyan, H; Webb, W R; Eich, R H

    1976-05-01

    One hundred and twenty patients undergoing aortocoronary bypass procedures were randomly placed into control and digitalized groups. All were initially in normal sinus rhythm and without evidence of congestive heart failure. Supraventricular arrhythmias occurred in 17 of 66 controls and in only three of 54 digitalized patients (P less than 0.01). There was no evidence of digitals toxicity. Based on this evidence we recommend prophylactic digitalization for patients having aortocoronary bypass operations.

  15. Digital holography and 3-D imaging.

    PubMed

    Banerjee, Partha; Barbastathis, George; Kim, Myung; Kukhtarev, Nickolai

    2011-03-01

    This feature issue on Digital Holography and 3-D Imaging comprises 15 papers on digital holographic techniques and applications, computer-generated holography and encryption techniques, and 3-D display. It is hoped that future work in the area leads to innovative applications of digital holography and 3-D imaging to biology and sensing, and to the development of novel nonlinear dynamic digital holographic techniques.

  16. Raynaud, digital ulcers and calcinosis in scleroderma.

    PubMed

    Nitsche, Alejandro

    2012-01-01

    Raynaud, digital ulcers and calcinosis are frequent manifestations of patients with systemic sclerosis. Digital ulcers are seen in more than half of the patients with scleroderma. Hospitalizations, ischemic complications and impairment of hand function are frequently observed in patients with digital ulcers, especially if treatment is delayed. Rapid and intensive treatment escalation in patients with scleroderma and refractory Raynaud's phenomenon is one of the most effective preventive action available in order to avoid the development of digital ulcers and tissue loss.

  17. Smartphone adapters for digital photomicrography

    PubMed Central

    Roy, Somak; Pantanowitz, Liron; Amin, Milon; Seethala, Raja R.; Ishtiaque, Ahmed; Yousem, Samuel A.; Parwani, Anil V.; Cucoranu, Ioan; Hartman, Douglas J.

    2014-01-01

    Background: Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. Materials and Methods: We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom) were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. Results: All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Conclusions: Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs. PMID:25191623

  18. The Role of a Digital Librarian in the Management of Digital Information Systems (DIS).

    ERIC Educational Resources Information Center

    Sreenivasulu, V.

    2000-01-01

    Discusses the need for digital librarians who will manage and organize digital libraries. Topics include digital information systems; the information superhighway; navigation, browsing, and filtering; multimedia searching and indexing; data mining; information access and retrieval; competencies and skills for a digital librarian; and professional…

  19. 47 CFR 76.640 - Support for unidirectional digital cable products on digital cable systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Support for unidirectional digital cable products on digital cable systems. 76.640 Section 76.640 Telecommunication FEDERAL COMMUNICATIONS... Standards § 76.640 Support for unidirectional digital cable products on digital cable systems. (a)...

  20. Differentiating Digital Writing Instruction: The Intersection of Technology, Writing Instruction, and Digital Genre Knowledge

    ERIC Educational Resources Information Center

    Martin, Nicole M.; Lambert, Claire

    2015-01-01

    U.S. adolescents' prior technology experiences and exposure to digital genres vary, but they will often write digital texts as they enter college and adulthood. We explored middle school students' digital writing instructional experience in the context of a university-based summer digital writing camp. The sixth- through eighth-grade adolescents…

  1. 47 CFR 76.640 - Support for unidirectional digital cable products on digital cable systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Support for unidirectional digital cable products on digital cable systems. 76.640 Section 76.640 Telecommunication FEDERAL COMMUNICATIONS... Standards § 76.640 Support for unidirectional digital cable products on digital cable systems. (a)...

  2. Modulation for terrestrial broadcasting of digital HDTV

    NASA Astrophysics Data System (ADS)

    Kohn, Elliott S.

    1991-12-01

    The digital modulation methods used by the DigiCipher, DSC-HDTV, ADTV, and ATVA-P digital high-definition television (HDTV) systems are discussed. Three of the systems use a quadrature amplitude modulation method, and the fourth uses a vestigial sideband modulation method. The channel equalization and spectrum sharing of the digital HDTV systems is discussed.

  3. Modulation for terrestrial broadcasting of digital HDTV

    NASA Technical Reports Server (NTRS)

    Kohn, Elliott S.

    1991-01-01

    The digital modulation methods used by the DigiCipher, DSC-HDTV, ADTV, and ATVA-P digital high-definition television (HDTV) systems are discussed. Three of the systems use a quadrature amplitude modulation method, and the fourth uses a vestigial sideband modulation method. The channel equalization and spectrum sharing of the digital HDTV systems is discussed.

  4. Indexing, Browsing, and Searching of Digital Video.

    ERIC Educational Resources Information Center

    Smeaton, Alan F.

    2004-01-01

    Presents a literature review that covers the following topics related to indexing, browsing, and searching of digital video: video coding and standards; conventional approaches to accessing digital video; automatically structuring and indexing digital video; searching, browsing, and summarization; measurement and evaluation of the effectiveness of…

  5. Digital Libraries--Methods and Applications

    ERIC Educational Resources Information Center

    Huang, Kuo Hung, Ed.

    2011-01-01

    Digital library is commonly seen as a type of information retrieval system which stores and accesses digital content remotely via computer networks. However, the vision of digital libraries is not limited to technology or management, but user experience. This book is an attempt to share the practical experiences of solutions to the operation of…

  6. Digital Photography and Its Impact on Instruction.

    ERIC Educational Resources Information Center

    Lantz, Chris

    Today the chemical processing of film is being replaced by a virtual digital darkroom. Digital image storage makes new levels of consistency possible because its nature is less volatile and more mutable than traditional photography. The potential of digital imaging is great, but issues of disk storage, computer speed, camera sensor resolution,…

  7. Digital Economy and Management in Spain.

    ERIC Educational Resources Information Center

    del Aguila, Ana R.; Padilla, Antonio; Serarols, Christian; Veciana, Jose M.

    2003-01-01

    Explains the digital economy and its impact on the firm. Highlights include subsectors of the digital economy, including infrastructure; analysis of the digital economy in Spain; analysis of the ICT (information and communication technology) sector in Spain; and electronic commerce through the Internet. (LRW)

  8. Digital Humanities: What Can Libraries Offer?

    ERIC Educational Resources Information Center

    Wong, Shun Han Rebekah

    2016-01-01

    The collaborative aspect of digital humanities is one of the core values of the field. Specialists and organizations involved in digital humanities partnerships may include individual scholars focusing on a particular area, multiple scholars across disciplines, computer scientists, or digital humanities centers. Through a quantitative analysis of…

  9. Embracing the Squishiness of Digital Literacy

    ERIC Educational Resources Information Center

    Chase, Zac; Laufenberg, Diana

    2011-01-01

    The thing about digital literacy is its inherent squishiness. Educators argue whether the tool or the purpose matters most. They debate whether something being "electronic" constitutes "digital." Does it need a screen? A keyboard? More than that, teachers must decide what it means to read and write digitally and how to assess…

  10. Picture Books in the Digital Age

    ERIC Educational Resources Information Center

    Serafini, Frank; Kachorsky, Danielle; Aguilera, Earl

    2016-01-01

    The design, publication, and features of contemporary narrative picturebooks have been impacted by the digital revolution and the emerging popularity of digital reading devices. Considering both the affordances and the limitations of digital picturebook apps can help readers, teachers, parents, and other educators make better decisions about the…

  11. DAM-ing the Digital Flood

    ERIC Educational Resources Information Center

    Raths, David

    2008-01-01

    With the widespread digitization of art, photography, and music, plus the introduction of streaming video, many colleges and universities are realizing that they must develop or purchase systems to preserve their school's digitized objects; that they must create searchable databases so that researchers can find and share copies of digital files;…

  12. Digital Library Education: Global Trends and Issues

    ERIC Educational Resources Information Center

    Shem, Magaji

    2015-01-01

    The paper examines trends and issues in digital education programmes globally, drawing examples of developmental growth of Library Information Science (LIS), schools and digital education courses in North America, Britain, and Southern Asia, the slow growth of LIS schools and digital education in Nigeria and some countries in Africa and India. The…

  13. Creating Trading Networks of Digital Archives.

    ERIC Educational Resources Information Center

    Cooper, Brian; Garcia-Molina, Hector

    Digital materials are vulnerable to a number of different kinds of failures, including decay of the digital media, loss due to hackers and viruses, accidental deletions, natural disasters, and bankruptcy of the institution holding the collection. Digital archives can best survive failures if they have made several copies of their collections at…

  14. Digital signal processing in microwave radiometers

    NASA Technical Reports Server (NTRS)

    Lawrence, R. W.; Stanley, W. D.; Harrington, R. F.

    1980-01-01

    A microprocessor based digital signal processing unit has been proposed to replace analog sections of a microwave radiometer. A brief introduction to the radiometer system involved and a description of problems encountered in the use of digital techniques in radiometer design are discussed. An analysis of the digital signal processor as part of the radiometer is then presented.

  15. Art, Storytelling, and the Digital Economy

    ERIC Educational Resources Information Center

    Ohier, Jason

    2007-01-01

    A digital story can be anything that uses digital technology to construct narrative. It comes in many forms, including short movies and documentaries, using still images, voice-over narration, and music. It can be academic, abstract, or highly personal. Digital storytelling provides a powerful media literacy opportunity, as students are required…

  16. A Digital Game for International Students' Adjustment

    ERIC Educational Resources Information Center

    Bisadi, Maryam; Chua, Alton Y. K; Keong, Lee Chu

    2013-01-01

    Although digital games have been developed for various subject areas, little attention has been focused on using digital games to address international students' adjustment issues. For this reason, this paper endeavors to explore the use of a digital game in facilitating international students acquire adjustment-related information. Specifically,…

  17. Examining Factors Predicting Students' Digital Competence

    ERIC Educational Resources Information Center

    Hatlevik, Ove Edvard; Guðmundsdóttir, Gréta Björk; Loi, Massimo

    2015-01-01

    The purpose of this study was to examine factors predicting lower secondary school students' digital competence and to explore differences between students when it comes to digital competence. Results from a digital competence test and survey in lower secondary school will be presented. It is important to learn more about and investigate what…

  18. Social Welfare Implications of the Digital Divide

    ERIC Educational Resources Information Center

    Kim, Eunjin; Lee, Byungtae; Menon, Nirup M.

    2009-01-01

    The Internet plays a critical role in informing individuals about society, politics, business, and the environment. So much so that it has been said that the digital divide makes the segment of society on the ''right side'' of the divide (the digitally endowed group) better off and that on the ''wrong side'' (the digitally challenged group) worse…

  19. Building a Digital Library on a Shoestring

    ERIC Educational Resources Information Center

    Boyd, Kate Foster; Creighton, Alma

    2006-01-01

    In this article, the authors discuss ways one can create a digital library on a shoestring despite the current high technology costs. Here, they describe the University of South Carolina's digital library development. The cost associated with building and maintaining the digital collections seems to have been worth it based on the feedback that…

  20. Diversity, Disability, and Geographic Digital Divide

    ERIC Educational Resources Information Center

    Sumari, Melati; Carr, Erika; Ndebe-Ngovo, Manjerngie

    2006-01-01

    The phenomenon called digital divide was the focus of this paper. Diversity, disability, and geographical digital divide were relevant to this collaborative project. An extensive review of the literature was conducted for the completion of this project. The evidence for the digital divide in terms of race, level of education, and gender in the…

  1. The Myth about the Digital Divide

    ERIC Educational Resources Information Center

    Hawkins, Brian L.; Oblinge, Diana G.

    2006-01-01

    Although computer ownership is not 100 percent, progress has been made on closing the digital divide. However, defining the digital divide according to the haves and have-nots of computer ownership is only a starting point. Beyond computer ownership, colleges and universities should explore the "second-level digital divide," which can be…

  2. Digital Forensics Using Local Signal Statistics

    ERIC Educational Resources Information Center

    Pan, Xunyu

    2011-01-01

    With the rapid growth of the Internet and the popularity of digital imaging devices, digital imagery has become our major information source. Meanwhile, the development of digital manipulation techniques employed by most image editing software brings new challenges to the credibility of photographic images as the definite records of events. We…

  3. Digital Advances in Contemporary Audio Production.

    ERIC Educational Resources Information Center

    Shields, Steven O.

    Noting that a revolution in sonic high fidelity occurred during the 1980s as digital-based audio production methods began to replace traditional analog modes, this paper offers both an overview of digital audio theory and descriptions of some of the related digital production technologies that have begun to emerge from the mating of the computer…

  4. A Historical Perspective on Digital Hearing Aids: How Digital Technology Has Changed Modern Hearing Aids

    PubMed Central

    Levitt, Harry

    2007-01-01

    This article provides the author's perspective on the development of digital hearing aids and how digital signal processing approaches have led to changes in hearing aid design. Major landmarks in the evolution of digital technology are identified, and their impact on the development of digital hearing aids is discussed. Differences between analog and digital approaches to signal processing in hearing aids are identified. PMID:17301334

  5. Digital micro-mirror devices in digital optical microscopy

    NASA Astrophysics Data System (ADS)

    Adeyemi, Adekunle Adesanya

    In this thesis, studies on the applications of digital micro-mirror devices (DMD) to enhancement of digital optical microscope images are presented. This involves adaptation of the fast switching capability and high optical efficiency of DMD to control the spatial illumination of the specimen. The first study focuses on a method of using DMD to enhance the dynamic range of a digital optical microscope. Our adaptive feedback illumination control method generates a high dynamic range image through an algorithm that combines the DMD-to-camera pixel geometrical mapping and a feedback operation. The feedback process automatically generates an illumination pattern in an iterative fashion that spatially modulates the DMD array elements on a pixel-by-pixel level. Via experiment, we demonstrate a transmitted-light microscope system that uses precise DMD control of a DMD-based projector to enhance the dynamic range ideally by a factor of 573. Results are presented showing approximately 5 times the camera dynamic range, enabling visualization over a wide range of specimen characteristics. The second study presents a technique for programming the source of the spherical reference illumination in a digital in-line holographic microscope using DMD. The programmable point source is achieved by individually addressing the elements of a DMD to spatially control the illumination of the object located at some distance from the source of the spherical reference field. Translation of the ON-state DMD mirror element changes the spatial location of the point source and consequently generates a sequence of translated holograms of the object. The experimental results obtained through numerical reconstruction of translated holograms of Latex microspheres shows the possibility of expanding the field of view by about 263% and also extracting depth information between features in an object volume. The common challenges associated with the use of DMD in coherent and broadband illumination

  6. 47 CFR 74.791 - Digital call signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Digital call signs. 74.791 Section 74.791... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low... −D. (b) Digital television translator stations. Call signs for digital television translator...

  7. 47 CFR 74.791 - Digital call signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Digital call signs. 74.791 Section 74.791... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low... −D. (b) Digital television translator stations. Call signs for digital television translator...

  8. 47 CFR 74.791 - Digital call signs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Digital call signs. 74.791 Section 74.791... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low... −D. (b) Digital television translator stations. Call signs for digital television translator...

  9. 47 CFR 74.791 - Digital call signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Digital call signs. 74.791 Section 74.791... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low... −D. (b) Digital television translator stations. Call signs for digital television translator...

  10. Parallel digital modem using multirate digital filter banks

    NASA Technical Reports Server (NTRS)

    Sadr, Ramin; Vaidyanathan, P. P.; Raphaeli, Dan; Hinedi, Sami

    1994-01-01

    A new class of architectures for an all-digital modem is presented in this report. This architecture, referred to as the parallel receiver (PRX), is based on employing multirate digital filter banks (DFB's) to demodulate, track, and detect the received symbol stream. The resulting architecture is derived, and specifications are outlined for designing the DFB for the PRX. The key feature of this approach is a lower processing rate then either the Nyquist rate or the symbol rate, without any degradation in the symbol error rate. Due to the freedom in choosing the processing rate, the designer is able to arbitrarily select and use digital components, independent of the speed of the integrated circuit technology. PRX architecture is particularly suited for high data rate applications, and due to the modular structure of the parallel signal path, expansion to even higher data rates is accommodated with each. Applications of the PRX would include gigabit satellite channels, multiple spacecraft, optical links, interactive cable-TV, telemedicine, code division multiple access (CDMA) communications, and others.

  11. Highly scalable digital front end architectures for digital printing

    NASA Astrophysics Data System (ADS)

    Staas, David

    2011-01-01

    HP's digital printing presses consume a tremendous amount of data. The architectures of the Digital Front Ends (DFEs) that feed these large, very fast presses have evolved from basic, single-RIP (Raster Image Processor) systems to multirack, distributed systems that can take a PDF file and deliver data in excess of 3 Gigapixels per second to keep the presses printing at 2000+ pages per minute. This paper highlights some of the more interesting parallelism features of our DFE architectures. The high-performance architecture developed over the last 5+ years can scale up to HP's largest digital press, out to multiple mid-range presses, and down into a very low-cost single box deployment for low-end devices as appropriate. Principles of parallelism pervade every aspect of the architecture, from the lowest-level elements of jobs to parallel imaging pipelines that feed multiple presses. From cores to threads to arrays to network teams to distributed machines, we use a systematic approach to move bottlenecks. The ultimate goals of these efforts are: to take the best advantage of the prevailing hardware options at our disposal; to reduce power consumption and cooling requirements; and to ultimately reduce the cost of the solution to our customers.

  12. Optimal digital redesign of cascaded analogue controllers

    NASA Technical Reports Server (NTRS)

    Shieh, L. S.; Decrocq, B. B.; Zhang, J. L.

    1991-01-01

    This paper presents a new, optimal digital redesign technique for finding an optimal cascaded digital controller from the given continuous-time counterpart by minimizing a quadratic performance index. The control gains can be obtained by solving a set of Liapunov equations. The developed optimal cascaded digital controller enables the state and/or outputs of the digitally controlled closed-loop sampled-data system to optimally match those of the original continuous-time closed-loop system at any instant between sampling periods. The developed control law can be implemented using inexpensive and reliable digital electronics with a relatively long sampling period.

  13. Intraoral Digital Impression Technique: A Review.

    PubMed

    Ting-Shu, Su; Jian, Sun

    2015-06-01

    With the techniques of computer-aided design and computer-aided manufacturing (CAD/CAM) being applied in the field of prosthodontics, a concept of intraoral digital impressions was put forward in the early 1980s. It has drawn comprehensive attention from dentists and has been used for dental prosthesis fabrication in a number of cases. This new digital impression technique is expected to bring about absolute digitization to the mode of prosthodontics. A few published articles have indicated that dental prostheses fabricated from intraoral digital impressions have exhibited remarkable advantages over those from conventional impressions in several respects. The present review discusses intraoral digital impression techniques in terms of the following aspects: (1) categories and principles of intraoral digital impression devices currently available; (2) operating characteristics of the devices; and (3) comparison of the manipulation, accuracy, and repeatability between intraoral digital impression and conventional impression.

  14. Visualizing Breath using Digital Holography

    NASA Astrophysics Data System (ADS)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  15. Coherent Digital Holographic Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Liu, Changgeng

    A new type of adaptive optics (AO) based on the principles of digital holography (DH) is proposed and developed for the use in wide-field and confocal retinal imaging. Digital holographic adaptive optics (DHAO) dispenses with the wavefront sensor and wavefront corrector of the conventional AO system. DH is an emergent imaging technology that gives direct numerical access to the phase of the optical field, thus allowing precise control and manipulation of the optical field. Incorporation of DH in an ophthalmic imaging system can lead to versatile imaging capabilities at substantially reduced complexity and cost of the instrument. A typical conventional AO system includes several critical hardware pieces: spatial light modulator, lenslet array, and a second CCD camera in addition to the camera for imaging. The proposed DHAO system replaces these hardware components with numerical processing for wavefront measurement and compensation of aberration through the principles of DH. (Abstract shortened by UMI.).

  16. Microscale Digital Vacuum Electronic Gates

    NASA Technical Reports Server (NTRS)

    Manohara, Harish (Inventor); Mojarradi, Mohammed M. (Inventor)

    2014-01-01

    Systems and methods in accordance with embodiments of the invention implement microscale digital vacuum electronic gates. In one embodiment, a microscale digital vacuum electronic gate includes: a microscale field emitter that can emit electrons and that is a microscale cathode; and a microscale anode; where the microscale field emitter and the microscale anode are disposed within at least a partial vacuum; where the microscale field emitter and the microscale anode are separated by a gap; and where the potential difference between the microscale field emitter and the microscale anode is controllable such that the flow of electrons between the microscale field emitter and the microscale anode is thereby controllable; where when the microscale anode receives a flow of electrons, a first logic state is defined; and where when the microscale anode does not receive a flow of electrons, a second logic state is defined.

  17. Digital data acquisition and processing.

    PubMed

    Naivar, Mark A; Galbraith, David W

    2015-01-05

    A flow cytometer is made up of many different subsystems that work together to measure the optical properties of individual cells within a sample. The data acquisition system (also called the data system) is one of these subsystems, and it is responsible for converting the electrical signals from the optical detectors into list-mode data. This unit describes the inner workings of the data system, and provides insight into how the instrument functions as a whole. Some of the information provided in this unit is applicable to everyday use of these instruments, and, at minimum, should make it easier for the reader to assemble a specific data system. With the considerable advancement of electronics technology, it becomes possible to build an entirely functional data system using inexpensive hobbyist-level electronics. This unit covers both analog and digital data systems, but the primary focus is on the more prevalent digital data systems of modern flow cytometric instrumentation.

  18. The Digital Morphological Sampling Theorem

    NASA Astrophysics Data System (ADS)

    Haralick, Robert M.; Zhuang, Xinhua; Lin, Charlotte; Lee, James

    1988-02-01

    There are potential industrial applications for any methodology which inherently reduces processing time and cost and yet produces results sufficiently close to the result of full processing. It is for this reason that a morphological sampling theorem is important. The morphological sampling theorem described in this paper states: (1) how a digital image must be morphologically filtered before sampling in order to preserve the relevant information after sampling; (2) to what precision an appropriately morphologically filtered image can be reconstructed after sampling; and (3) the relationship between morphologically operating before sampling and the more computationally efficient scheme of morphologically operating on the sampled image with a sampled structuring element. The digital sampling theorem is developed first for the case of binary morphology and then it is extended to gray scale morphology through the use of the umbra homomorphism theorems.

  19. Vibration analysis using digital correlation

    NASA Technical Reports Server (NTRS)

    Gilbert, John A.; Lehner, David L.; Dudderar, T. Dixon; Matthys, Donald R.

    1988-01-01

    This paper demonstrates the use of a computer-based optical method for locating the positions of nodes and antinodes in vibrating members. Structured light patterns are projected at an angle onto the vibrating surface using a 35 mm slide projector. The vibrating surface and the projected images are captured in a time averaged photograph which is subsequently digitized. The inherent fringe patterns are filtered to determine amplitudes of vibration, and computer programs are used to compare the time averaged images to images recorded prior to excitation to locate nodes and antinodes. Some of the influences of pattern regularity on digital correlation are demonstrated, and a speckle-based method for determining the mode shapes and the amplitudes of vibration with variable sensitivity is suggested.

  20. Evaluate interference in digital channels

    NASA Technical Reports Server (NTRS)

    Davarian, F.; Sumida, J.

    1985-01-01

    Any future mobile satellite service (MSS) which is to provide simultaneous mobile communications for a large number of users will have to make very efficient use of the spectrum. As the spectrum available for an MSS is limited, the system's channels should be packed as closely together as possible, with minimum-width guard bands. In addition the employment of frequency reuse schemes is an important factor. Difficulties regarding these solutions are related to the introduction of interference in the link. A balance must be achieved between the competing aims of spectrum conservation and low interference. While the interference phenomenon in narrowband FM voice channels is reasonably well understood, very little effort, however, has been devoted to the problem in digital radios. Attention is given to work, which illuminates the effects of cochannel and adjacent channel interference on digital FM (FSK) radios.

  1. Digital government and public health.

    PubMed

    Fountain, Jane E

    2004-10-01

    Digital government is typically defined as the production and delivery of information and services inside government and between government and the public using a range of information and communication technologies. Two types of government relationships with other entities are government-to-citizen and government-to-government relationships. Both offer opportunities and challenges. Assessment of a public health agency's readiness for digital government includes examination of technical, managerial, and political capabilities. Public health agencies are especially challenged by a lack of funding for technical infrastructure and expertise, by privacy and security issues, and by lack of Internet access for low-income and marginalized populations. Public health agencies understand the difficulties of working across agencies and levels of government, but the development of new, integrated e-programs will require more than technical change - it will require a profound change in paradigm.

  2. A telerobotic digital controller system

    NASA Technical Reports Server (NTRS)

    Brown, Richard J.

    1992-01-01

    This system is a network of joint mounted dual axes digital servo-controllers (DDSC), providing control of various joints and end effectors of different robotic systems. This report provides description of and user required information for the Digital Controller System Network (DSCN) and, in particular, the DDSC, Model DDSC-2, developed to perform the controller functions. The DDSC can control 3 phase brushless or brush type DC motors, requiring up to 8 amps. Only four wires, two for power and 2 for serial communication, are required, except for local sensor and motor connections. This highly capable, very flexible, programmable servo-controller, contained on a single, compact printed circuit board measuring only 4.5 x 5.1 inches, is applicable to control systems of all types from sub-arc second precision pointing to control of robotic joints and end effectors. This document concentrates on the robotic applications for the DDSC.

  3. Cold Injury of Amputated Digits

    DTIC Science & Technology

    2005-05-01

    preservation is appropriate, if conducted properly. Since digits contain no muscle tissue, irreversible damage appears after significantly longer...vulnerable. Vascular changes lead to thrombotic occlusion of arteries and veins, causing vascular spasms and subsequent diminished blood supply to the...project no. M2-0018) from the Ministry of Defence and Ministry of Education, Science and Sport of the Republic of Slovenia. 6.0 REFERENCES [1

  4. High Performance Proactive Digital Forensics

    NASA Astrophysics Data System (ADS)

    Alharbi, Soltan; Moa, Belaid; Weber-Jahnke, Jens; Traore, Issa

    2012-10-01

    With the increase in the number of digital crimes and in their sophistication, High Performance Computing (HPC) is becoming a must in Digital Forensics (DF). According to the FBI annual report, the size of data processed during the 2010 fiscal year reached 3,086 TB (compared to 2,334 TB in 2009) and the number of agencies that requested Regional Computer Forensics Laboratory assistance increasing from 689 in 2009 to 722 in 2010. Since most investigation tools are both I/O and CPU bound, the next-generation DF tools are required to be distributed and offer HPC capabilities. The need for HPC is even more evident in investigating crimes on clouds or when proactive DF analysis and on-site investigation, requiring semi-real time processing, are performed. Although overcoming the performance challenge is a major goal in DF, as far as we know, there is almost no research on HPC-DF except for few papers. As such, in this work, we extend our work on the need of a proactive system and present a high performance automated proactive digital forensic system. The most expensive phase of the system, namely proactive analysis and detection, uses a parallel extension of the iterative z algorithm. It also implements new parallel information-based outlier detection algorithms to proactively and forensically handle suspicious activities. To analyse a large number of targets and events and continuously do so (to capture the dynamics of the system), we rely on a multi-resolution approach to explore the digital forensic space. Data set from the Honeynet Forensic Challenge in 2001 is used to evaluate the system from DF and HPC perspectives.

  5. Digital Control For Remote Manipulators

    NASA Technical Reports Server (NTRS)

    Bejczy, Antal K.; Dotson, Ronald S.

    1987-01-01

    Multiple microprocessors enable large separations between controllers and manipulators. Controller for remote manipulator requires no direct mechanical connection between slave arm and master arm moved by human operator. Employs two-way digital data transmission rather than mechanical linkage between master and slave. Manipulator a considerable distance from operator. Software for controller distributed between master and slave locations. Organized into modules. Hardware and software for system demonstrated in laboratory model.

  6. Digital electronic engine control history

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.

    1984-01-01

    Full authority digital electronic engine controls (DEECs) were studied, developed, and ground tested because of projected benefits in operability, improved performance, reduced maintenance, improved reliability, and lower life cycle costs. The issues of operability and improved performance, however, are assessed in a flight test program. The DEEC on a F100 engine in an F-15 aircraft was demonstrated and evaluated. The events leading to the flight test program are chronicled and important management and technical results are identified.

  7. Integrated Services Digital Network (ISDN).

    DTIC Science & Technology

    1985-06-01

    This thesis contains development of a conceptual framework for an Integrated Services Digital Network (ISDN) and relates ISDN concepts to non...tactical Department of Defense (DoD) communications applications. The conceptual framework developed is non-technical and is intended to provide general...characteristics of ISDN, is also discussed in terms of the conceptual framework developed. General ISDN concepts are also related to DoD applications. The

  8. Digital Images and Human Vision

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Null, Cynthia H. (Technical Monitor)

    1997-01-01

    Processing of digital images destined for visual consumption raises many interesting questions regarding human visual sensitivity. This talk will survey some of these questions, including some that have been answered and some that have not. There will be an emphasis upon visual masking, and a distinction will be drawn between masking due to contrast gain control processes, and due to processes such as hypothesis testing, pattern recognition, and visual search.

  9. The digital library: an oxymoron?

    PubMed

    Guédon, J C

    1999-01-01

    "Virtual libraries" and "digital libraries" have become stock phrases of our times. But what do they really mean? While digital refers to a new form of document encoding and must be approached from that perspective, virtual resonates with aspects that modern philosophy treats with benign neglect at best. The word virtual harbors the notion of potential, and therein lies its hidden strength. Although strong commercial interests try to use the shift to a digital environment to redefine the political economy of knowledge, and thus virtualize libraries into a state of almost complete impotence, all hope is not lost. Librarians of virtualized libraries may well discover that they have re-empowered institutions if they place human interaction at the heart of their operations. In other words, rather than envisioning themselves as knowledge bankers sitting on treasure vaults of knowledge, they should see themselves as "hearts" dynamizing human communities. They should also see themselves as an essential part of these communities, and not as external repositories of knowledge. In this fashion, they will avoid the fate of becoming an oxymoron.

  10. RSFQ Baseband Digital Signal Processing

    NASA Astrophysics Data System (ADS)

    Herr, Anna Yurievna

    Ultra fast switching speed of superconducting digital circuits enable realization of Digital Signal Processors with performance unattainable by any other technology. Based on rapid-single-flux technology (RSFQ) logic, these integrated circuits are capable of delivering high computation capacity up to 30 GOPS on a single processor and very short latency of 0.1ns. There are two main applications of such hardware for practical telecommunication systems: filters for superconducting ADCs operating with digital RF data and recursive filters at baseband. The later of these allows functions such as multiuser detection for 3G WCDMA, equalization and channel precoding for 4G OFDM MIMO, and general blind detection. The performance gain is an increase in the cell capacity, quality of service, and transmitted data rate. The current status of the development of the RSFQ baseband DSP is discussed. Major components with operating speed of 30GHz have been developed. Designs, test results, and future development of the complete systems including cryopackaging and CMOS interface are reviewed.

  11. Digital electrospray for controlled deposition.

    PubMed

    Deng, Weiwei; Waits, C Mike; Gomez, Alessandro

    2010-03-01

    Many novel functional structures are now fabricated by controlled deposition as a maskless, bottom-up fabrication technique. These applications require rapid and precise deposition of minute amounts of solutions/suspensions or their ultimate particle products in predefined patterns. The electrospray is a promising alternative to the commonly used inkjet printing because it can easily handle highly viscous liquid, avoid high shear rates, and has low risk of clogging. We demonstrate a proof-of-concept digital electrospray. This system consists of a 61-nozzle array microfabricated in silicon and a 61-element digital extractor fabricated using flexible polyimide substrates. "Digital" refers to the state of each electrospray source that can be tuned either on or off independently and responsively. We showed a resolution of 675 mum and a response frequency up to 100 Hz. With similar design and industry standard fabrication procedures, it is feasible to scale up the system to O(1000) sources with spatial resolution better than 250 mum and a O(kHz) response frequency. The latter is controlled by the viscous damping time.

  12. Wideband Agile Digital Microwave Radiometer

    NASA Technical Reports Server (NTRS)

    Gaier, Todd C.; Brown, Shannon T.; Ruf, Christopher; Gross, Steven

    2012-01-01

    The objectives of this work were to take the initial steps needed to develop a field programmable gate array (FPGA)- based wideband digital radiometer backend (>500 MHz bandwidth) that will enable passive microwave observations with minimal performance degradation in a radiofrequency-interference (RFI)-rich environment. As manmade RF emissions increase over time and fill more of the microwave spectrum, microwave radiometer science applications will be increasingly impacted in a negative way, and the current generation of spaceborne microwave radiometers that use broadband analog back ends will become severely compromised or unusable over an increasing fraction of time on orbit. There is a need to develop a digital radiometer back end that, for each observation period, uses digital signal processing (DSP) algorithms to identify the maximum amount of RFI-free spectrum across the radiometer band to preserve bandwidth to minimize radiometer noise (which is inversely related to the bandwidth). Ultimately, the objective is to incorporate all processing necessary in the back end to take contaminated input spectra and produce a single output value free of manmade signals to minimize data rates for spaceborne radiometer missions. But, to meet these objectives, several intermediate processing algorithms had to be developed, and their performance characterized relative to typical brightness temperature accuracy re quirements for current and future microwave radiometer missions, including those for measuring salinity, soil moisture, and snow pack.

  13. Digital first order hold circuit

    NASA Technical Reports Server (NTRS)

    Chan, Fred N. (Inventor); Wensley, Gerald J. (Inventor)

    1989-01-01

    There is provided a digitally controlled first order hold circuit and waveform synthesizer for digitally controlling the representation of a function over an approximation interval. In accordance with the operation of the invention, the first order hold circuit and waveform generator receives a digital data input signal which contains initial condition data, up/down data, and slope data for the approximation interval. The initial condition data is loaded into an up/down counter which is incremented using counting data at a rate depending on the value of the slope data and in a direction depending on the value of the up-down data. In order to minimize delays arising from data acquistion, two frequency synthesizer circuits are provided such that one frequency synthesizer provides counting data while the other frequency synthesizer receives slope data. During alternating intervals, the other frequency synthesizer circuit provides counting data while the other circuit receives slope data. In addition, long length data input signals covering a plurality of approximation intervals are provided to reduce the demands on a main system central processing unit.

  14. The digital library: an oxymoron?

    PubMed Central

    Guédon, J C

    1999-01-01

    "Virtual libraries" and "digital libraries" have become stock phrases of our times. But what do they really mean? While digital refers to a new form of document encoding and must be approached from that perspective, virtual resonates with aspects that modern philosophy treats with benign neglect at best. The word virtual harbors the notion of potential, and therein lies its hidden strength. Although strong commercial interests try to use the shift to a digital environment to redefine the political economy of knowledge, and thus virtualize libraries into a state of almost complete impotence, all hope is not lost. Librarians of virtualized libraries may well discover that they have re-empowered institutions if they place human interaction at the heart of their operations. In other words, rather than envisioning themselves as knowledge bankers sitting on treasure vaults of knowledge, they should see themselves as "hearts" dynamizing human communities. They should also see themselves as an essential part of these communities, and not as external repositories of knowledge. In this fashion, they will avoid the fate of becoming an oxymoron. PMID:9934524

  15. IDSP- INTERACTIVE DIGITAL SIGNAL PROCESSOR

    NASA Technical Reports Server (NTRS)

    Mish, W. H.

    1994-01-01

    The Interactive Digital Signal Processor, IDSP, consists of a set of time series analysis "operators" based on the various algorithms commonly used for digital signal analysis work. The processing of a digital time series to extract information is usually achieved by the application of a number of fairly standard operations. However, it is often desirable to "experiment" with various operations and combinations of operations to explore their effect on the results. IDSP is designed to provide an interactive and easy-to-use system for this type of digital time series analysis. The IDSP operators can be applied in any sensible order (even recursively), and can be applied to single time series or to simultaneous time series. IDSP is being used extensively to process data obtained from scientific instruments onboard spacecraft. It is also an excellent teaching tool for demonstrating the application of time series operators to artificially-generated signals. IDSP currently includes over 43 standard operators. Processing operators provide for Fourier transformation operations, design and application of digital filters, and Eigenvalue analysis. Additional support operators provide for data editing, display of information, graphical output, and batch operation. User-developed operators can be easily interfaced with the system to provide for expansion and experimentation. Each operator application generates one or more output files from an input file. The processing of a file can involve many operators in a complex application. IDSP maintains historical information as an integral part of each file so that the user can display the operator history of the file at any time during an interactive analysis. IDSP is written in VAX FORTRAN 77 for interactive or batch execution and has been implemented on a DEC VAX-11/780 operating under VMS. The IDSP system generates graphics output for a variety of graphics systems. The program requires the use of Versaplot and Template plotting

  16. Research highlights: digital assays on chip.

    PubMed

    Kim, Donghyuk; Wei, Qingshan; Kong, Janay Elise; Ozcan, Aydogan; Di Carlo, Dino

    2015-01-07

    The ability to break up a volume of fluid into smaller pieces that are confined or separated to prevent molecular communication/transport is a key capability intrinsic to microfluidic systems. This capability has been used to develop or implement digital versions of traditional molecular analysis assays, including digital PCR and digital immunoassays/ELISA. In these digital versions, the concentration of the target analyte is in a range such that, when sampled into smaller fluid volumes, either a single molecule or no molecule may be present. Subsequent amplification is sensitive enough to obtain a digital readout of the presence of these target molecules. Advantages of such approaches that are claimed include quantification without calibration and robustness to variations in reaction conditions or times because the digital readout is less sensitive to absolute signal intensity levels. Weaknesses of digital approaches include a lower dynamic range of concentrations over which the assay is sensitive, which depends on the total volume that can be analyzed. We highlight recent efforts to expand the dynamic range of digital assays based on exploiting reaction/diffusion phenomena. A side-by-side study that evaluates the strengths of digital assays reveals that the majority of these claims are supported, with specific caveats. Finally, we highlight approaches to apply digital assays to analyze new types of reactions, including the active transport of protons across membranes by ATPases at the single protein level - perhaps opening up new biophysical understanding and screening opportunities, similar to widely deployed single-molecule ion channel analysis.

  17. Digital Filters for Digital Phase-locked Loops

    NASA Technical Reports Server (NTRS)

    Simon, M.; Mileant, A.

    1985-01-01

    An s/z hybrid model for a general phase locked loop is proposed. The impact of the loop filter on the stability, gain margin, noise equivalent bandwidth, steady state error and time response is investigated. A specific digital filter is selected which maximizes the overall gain margin of the loop. This filter can have any desired number of integrators. Three integrators are sufficient in order to track a phase jerk with zero steady state error at loop update instants. This filter has one zero near z = 1.0 for each integrator. The total number of poles of the filter is equal to the number of integrators plus two.

  18. Digital hardware and computer system for a digital image recorder.

    NASA Technical Reports Server (NTRS)

    Dennison, E. W.

    1973-01-01

    Description of the digital memory and related computer system used at the Palomar Mountain Observatory. The memory was designed to have a large number of pixels, a high capacity for each pixel, and fast access for use with a variety of image sensors. As an image integration and storage device, this memory is shown to possess ideal properties, namely, it is strictly linear, has a wide dynamic range, and the image does not deteriorate with time. The observer has a visual display which enables him to monitor the image as it is being integrated.-

  19. Digital imaging technology assessment: Digital document storage project

    NASA Technical Reports Server (NTRS)

    1989-01-01

    An ongoing technical assessment and requirements definition project is examining the potential role of digital imaging technology at NASA's STI facility. The focus is on the basic components of imaging technology in today's marketplace as well as the components anticipated in the near future. Presented is a requirement specification for a prototype project, an initial examination of current image processing at the STI facility, and an initial summary of image processing projects at other sites. Operational imaging systems incorporate scanners, optical storage, high resolution monitors, processing nodes, magnetic storage, jukeboxes, specialized boards, optical character recognition gear, pixel addressable printers, communications, and complex software processes.

  20. Digital system identification and its application to digital flight control

    NASA Technical Reports Server (NTRS)

    Kotob, S.; Kaufman, H.

    1974-01-01

    On-line system identification of linear discrete systems for implementation in a digital adaptive flight controller is considered by the conventional extended Kalman filter and a decoupling process in which the linear state estimation problem and the linear parameter identification problem are each treated separately and alternately. Input requirements for parameter identifiability are established using the standard conditions of observability for a time variant system. Experimental results for simulated linearized lateral aircraft motion are included along with the effect of different initialization and updating procedures for the priming trajectory used by the filter.

  1. Bandwidth Efficient Wireless Digital Modem Developed

    NASA Technical Reports Server (NTRS)

    Kifle, Muli

    1999-01-01

    NASA Lewis Research Center has developed a digital approach for broadcasting highfidelity audio (nearly compact disk (CD) quality sound) in the commercial frequencymodulated (FM) broadcast band. This digital approach provides a means of achieving high data transmission rates with low hardware complexity--including low mass, size, and power consumption. Lewis has completed the design and prototype development of a bandwidth-efficient digital modem (modulator and demodulator) that uses a spectrally efficient modulation scheme: 16-ary rectangular quadrature amplitude modulation, or 16- ary QAM. The digital implementation is based strictly on inexpensive, commercial off-theshelf digital signal processing (DSP) hardware to perform up and down conversions and pulse shaping. The digital modem transmits data at rates up to 76 kilobits per second (kbps), which is almost 3 times faster than standard 28.8-kbps telephone modems. In addition, the modem offers improved power and spectral performance, flexible operation, and low-cost implementation.

  2. Digital diagnosis of medical images

    NASA Astrophysics Data System (ADS)

    Heinonen, Tomi; Kuismin, Raimo; Jormalainen, Raimo; Dastidar, Prasun; Frey, Harry; Eskola, Hannu

    2001-08-01

    The popularity of digital imaging devices and PACS installations has increased during the last years. Still, images are analyzed and diagnosed using conventional techniques. Our research group begun to study the requirements for digital image diagnostic methods to be applied together with PACS systems. The research was focused on various image analysis procedures (e.g., segmentation, volumetry, 3D visualization, image fusion, anatomic atlas, etc.) that could be useful in medical diagnosis. We have developed Image Analysis software (www.medimag.net) to enable several image-processing applications in medical diagnosis, such as volumetry, multimodal visualization, and 3D visualizations. We have also developed a commercial scalable image archive system (ActaServer, supports DICOM) based on component technology (www.acta.fi), and several telemedicine applications. All the software and systems operate in NT environment and are in clinical use in several hospitals. The analysis software have been applied in clinical work and utilized in numerous patient cases (500 patients). This method has been used in the diagnosis, therapy and follow-up in various diseases of the central nervous system (CNS), respiratory system (RS) and human reproductive system (HRS). In many of these diseases e.g. Systemic Lupus Erythematosus (CNS), nasal airways diseases (RS) and ovarian tumors (HRS), these methods have been used for the first time in clinical work. According to our results, digital diagnosis improves diagnostic capabilities, and together with PACS installations it will become standard tool during the next decade by enabling more accurate diagnosis and patient follow-up.

  3. Digital processing system for developing countries

    NASA Technical Reports Server (NTRS)

    Nanayakkara, C.; Wagner, H.

    1977-01-01

    An effort was undertaken to perform simple digital processing tasks using pre-existing general purpose digital computers. An experimental software package, LIGMALS, was obtained and modified for this purpose. The resulting software permits basic processing tasks to be performed including level slicing, gray mapping and ratio processing. The experience gained in this project indicates a possible direction which may be used by other developing countries to obtain digital processing capabilities.

  4. The future of digital imaging in dentistry.

    PubMed

    Miles, D A; Razzano, M R

    2000-04-01

    Digital radiographic imaging in dentistry has matured. All the reasons dentists have cited for keeping conventional, film-based systems have been refuted: cost, sensors, storage, and training are not issues. There are many reasons to switch to digital. This article outlines external factors that dentists may not have considered that will influence the way they conduct business in their offices related to radiographic imaging. The evidence points to the inevitable adoption of digital imaging systems.

  5. A Framework for Automated Digital Forensic Reporting

    DTIC Science & Technology

    2009-03-01

    use, the report should make a note that private browsing or history erasing may have been conducted. Media reporting (still image, audio and video...provide a wealth of revealing information when examining a case. In this context, digital media is defined as digital photos, video, and audio . Digital...can then be parsed with a regular expression and mapped to the PyFlag relevant fields for inclusion in the database. For example, a steganography

  6. Digital holographic nondestructive testing of laminate composite

    NASA Astrophysics Data System (ADS)

    Karray, Mayssa; Christophe, Poilane; Gargouri, Mohamed; Picart, Pascal

    2016-09-01

    Optical digital holographic techniques can be used for nondestructive testing of materials. Digital holographic nondestructive testing essentially measures deformations on the surface of the object. However, there is sufficient sensitivity to detect subsurface and internal defects in metallic and composite specimens. We investigate and discuss the vibration analysis of laminated composite glass-epoxy using time averaging in digital Fresnel holography to visualize the modes of vibration and to test the integrity of the structures of studied materials.

  7. 2015 National Agenda for Digital Stewardship

    DTIC Science & Technology

    2014-09-01

    2015 NATIONAL AGENDA FOR DIGITAL STEWARDSHIP September 2014 A report on the challenges, opportunities, gaps, emerging...trends, and key areas for research and development that support the national capacity for digital stewardship. Authored by the NDSA Coordinating...Agenda for Digital Stewardship 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

  8. Application of Compressive Sensing to Digital Holography

    DTIC Science & Technology

    2015-05-01

    AFRL-RY-WP-TR-2015-0071 APPLICATION OF COMPRESSIVE SENSING TO DIGITAL HOLOGRAPHY Mark Neifeld University of Arizona...From - To) May 2015 Final 3 September 2013 – 27 February 2015 4. TITLE AND SUBTITLE APPLICATION OF COMPRESSIVE SENSING TO DIGITAL HOLOGRAPHY 5a...from under- sampled data. This work presents a new reconstruction algorithm for use with under-sampled digital holography measurements and yields

  9. Digital Model of Railway Electric Traction Lines

    NASA Astrophysics Data System (ADS)

    Garg, Rachana; Mahajan, Priya; Kumar, Parmod

    2016-08-01

    The characteristic impedance and propagation constant define the behavior of signal propagation over the transmission lines. The digital model for railway traction lines which includes railway tracks is developed, using curve fitting technique in MATLAB. The sensitivity of this model has been computed with respect to frequency. The digital sensitivity values are compared with the values of analog sensitivity. The developed model is useful for digital protection, integrated operation, control and planning of the system.

  10. Perceptual watermarks for digital images and video

    NASA Astrophysics Data System (ADS)

    Wolfgang, Raymond B.; Podilchuk, Christine I.; Delp, Edward J., III

    1999-04-01

    The growth of new imaging technologies has created a need for techniques that can be used for copyright protection of digital images. One approach for copyright protection is to introduce an invisible signal known as a digital watermark in the image. In this paper, we describe digital image watermarking techniques known as perceptually watermarks that are designed to exploit aspects of the human visual system in order to produce a transparent, yet robust watermark.

  11. The quantum vector digital voltmeter of INMETRO

    NASA Astrophysics Data System (ADS)

    Kuerten Ihlenfeld, Waldemar G.; Landim, Regis P.

    2016-07-01

    The paper describes the quantum vector digital voltmeter developed at INMETRO, which is based on a programmable Josephson voltage synthesizer. The system employs digital regulation for phase-alignment and frequency synchronization of signals, is fully automated and allows calibration of ac sources and analog-to-digital converters with uncertainties bearing some parts of 10-07 up to frequencies of around 500 Hz.

  12. Digital Controller For Emergency Beacon

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    1990-01-01

    Prototype digital controller intended for use in 406-MHz emergency beacon. Undergoing development according to international specifications, 406-MHz emergency beacon system includes satellites providing worldwide monitoring of beacons, with Doppler tracking to locate each beacon within 5 km. Controller turns beacon on and off and generates binary codes identifying source (e.g., ship, aircraft, person, or vehicle on land). Codes transmitted by phase modulation. Knowing code, monitor attempts to communicate with user, monitor uses code information to dispatch rescue team appropriate to type and locations of carrier.

  13. Digital podoscope for remote diagnosis

    NASA Astrophysics Data System (ADS)

    Silva Moreno, Alejandra A.; Chávez Gutiérrez, Francisco

    2011-10-01

    Nowadays the measurement of the contact area of the foot has become an objective way of classifying feet and to describe the form of the longitudinal arch of the foot. In this work, the implementation of a digital podoscope that enables remote sensing for evaluation of the foot is described. The podogram includes an outline of the plantar pressure, and the contour of the arch. This method of evaluation is relatively simple and inexpensive while maintaining precision. The recognition system compares the image of the actual foot with that of a reference image. Information from the comparison can be sent by internet to obtain a remote diagnosis from an expert.

  14. High speed holographic digital recorder.

    PubMed

    Roberts, H N; Watkins, J W; Johnson, R H

    1974-04-01

    Concepts, feasibility experiments, and key component developments are described for a holographic digital record/reproduce system with the potential for 1.0 Gbit/sec rates and higher. Record rates of 500 Mbits/sec have been demonstrated with a ten-channel acoustooptic modulator array and a mode-locked, cavity-dumped argon-ion laser. Acoustooptic device technology has been advanced notably during the development of mode lockers, cavity dumpers, beam deflectors, and multichannel modulator arrays. The development of high speed multichannel photodetector arrays for the readout subsystem requires special attention. The feasibility of 1.0 Gbits/sec record rates has been demonstrated.

  15. Personal Digital Libraries of Email

    NASA Astrophysics Data System (ADS)

    Gross, Benjamin M.

    In this paper, I describe the results of user interviews that reveal problems in current email systems, including role conflict, high cognitive overhead associated with organization and retrieval, inability to navigate conversations and difficulties in addressing messages. I also describe the design of a prototype system with an underlying message store for the email collection. Services layered on top of the message store address many problems described by users through improved support for identity and role management, authority control and query interfaces. Many of the solutions described in this paper to improve management of personal email collections can also be applied to other digital library collections.

  16. Frequency analysis of digital holography

    NASA Astrophysics Data System (ADS)

    Kreis, Thomas M.

    2002-04-01

    A coherent optical imaging system consisting of recording a digital hologram by a CCD array and numerical reconstruction of the complex wave field in a computer is subjected to a frequency analysis. This analysis recognizes Fresnel and lensless Fourier transform holography; collimated and divergent reference waves; as well as the real image, the virtual image, and the dc term. The influences of finite sampling and the fill factor of the CCD pixels are examined. The impulse response of the system is a shifted Fraunhofer diffraction pattern of the aperture defined by the CCD. A fill factor below unity leads to a contrast decrease, which is quantitatively described in the modulation transfer function.

  17. Digital Ischemia Associated With Cancer

    PubMed Central

    Le Besnerais, Maëlle; Miranda, Sébastien; Cailleux, Nicole; Girszyn, Nicolas; Marie, Isabelle; Lévesque, Hervé; Benhamou, Ygal

    2014-01-01

    Abstract Digital ischemia associated with cancer (DIAC) is increasing in frequency and recent reports have suggested the concept of paraneoplastic manifestation. The aims of this study were to characterize the clinical presentation of DIAC and identify clinical features that could lead physicians to diagnose underlying cancer. From January 2004 to December 2011, 100 patients were hospitalized in the Department of Internal Medicine at Rouen University Hospital, France for a first episode of DI. Fifteen (15%) exhibited symptomatic or asymptomatic cancer during the year preceding or following vascular episode and constituted the DIAC group. Other patients without cancer made up the digital ischemia (DI) group. Median time between diagnosis of cancer and episode of digital necrosis was 2 months [0.25–9]. Diagnosis of DI and concomitant cancer was made in 7 of the 15 patients, while DI preceded the malignant disorder in 2 cases and followed it in 6 cases. Histological types were adenocarcinoma for 7 (46.7%), squamous cell carcinoma for 4 (26.7%), and lymphoid neoplasia for 3 patients (20%). Six patients (40%) had extensive cancer. Three patients were lost to follow-up and 5 patients died <1 year after diagnosis of cancer. Cancer treatment improved vascular symptoms in 6 patients (40%). Patients with DIAC, compared to patients with DI, were significantly older (56 years [33–79] vs 46 [17–83] P =0.005), and had significantly lower hemoglobin and hematocrit levels (12.7 g/dl vs 13.9 g/dl; P =0.003 and 38% vs 42%; P =0.003, respectively). Patients with DIAC had a higher platelet rate (420 vs 300 G/L P =0.01), and 6 patients with DIAC (40%) had thrombocytosis. There was no difference between groups either in C-reactive protein level (12 mg/L vs 5 mg/L; P =0.08) or regarding cardiovascular risk factors, presence of autoimmunity, or monoclonal protein. This retrospective study suggests that DIAC may be more prevalent than previously reported. Outcomes

  18. Color spaces in digital video

    SciTech Connect

    Gaunt, R.

    1997-05-01

    Whether it`s photography, computer graphics, publishing, or video; each medium has a defined color space, or gamut, which defines the extent that a given set of RGB colors can be mixed. When converting from one medium to another, an image must go through some form of conversion which maps colors into the destination color space. The conversion process isn`t always straight forward, easy, or reversible. In video, two common analog composite color spaces are Y`tjv (used in PAL) and Y`IQ (used in NTSC). These two color spaces have been around since the beginning of color television, and are primarily used in video transmission. Another analog scheme used in broadcast studios is Y`, R`-Y`, B`-Y` (used in Betacam and Mll) which is a component format. Y`, R`-Y`,B`-Y` maintains the color information of RGB but in less space. From this, the digital component video specification, ITU-Rec. 601-4 (formerly CCIR Rec. 601) was based. The color space for Rec. 601 is symbolized as Y`CbCr. Digital video formats such as DV, Dl, Digital-S, etc., use Rec. 601 to define their color gamut. Digital composite video (for D2 tape) is digitized analog Y`UV and is seeing decreased use. Because so much information is contained in video, segments of any significant length usually require some form of data compression. All of the above mentioned analog video formats are a means of reducing the bandwidth of RGB video. Video bulk storage devices, such as digital disk recorders, usually store frames in Y`CbCr format, even if no other compression method is used. Computer graphics and computer animations originate in RGB format because RGB must be used to calculate lighting and shadows. But storage of long animations in RGB format is usually cost prohibitive and a 30 frame-per-second data rate of uncompressed RGB is beyond most computers. By taking advantage of certain aspects of the human visual system, true color 24-bit RGB video images can be compressed with minimal loss of visual information

  19. Digital holography based submicron thermometry.

    PubMed

    Moradi, Amin; Akhlaghi, Ehsan A; Hajizedeh, Faegheh; Reihani, S Nader S

    2016-12-12

    Here we introduce a phase-shifting digital holography-based method to determine the temperature profile around an irradiated (sub-)micron spherical bead. The method utilizes a Mach-Zehnder interferometer implemented into an open setup microscope. The results of irradiated gold spheres with diameter of 400 nm and also silver-coated micron-sized silica beads embedded in silicone oil are presented. We show that the applied method is able to accurately determine the surface temperature with accuracy of 1 °C. Our experimental results perfectly confirm the theoretical prediction of temperature profile around the irradiated bead.

  20. Geometric phase shifting digital holography.

    PubMed

    Jackin, Boaz Jessie; Narayanamurthy, C S; Yatagai, Toyohiko

    2016-06-01

    A new phase shifting digital holographic technique using a purely geometric phase in Michelson interferometric geometry is proposed. The geometric phase in the system does not depend upon either optical path length or wavelength, unlike dynamic phase. The amount of geometric phase generated is controllable through a rotating wave plate. The new approach has unique features and major advantages in holographic measurement of transparent and reflecting three-dimensional (3D) objects. Experimental results on surface shape measurement and imaging of 3D objects are presented using the proposed method.

  1. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1995-05-09

    A device is described for stimulating bone tissue by applying a low level alternating current signal directly to the patient`s skin. A crystal oscillator, a binary divider chain and digital logic gates are used to generate the desired waveforms that reproduce the natural electrical characteristics found in bone tissue needed for stimulating bone growth and treating osteoporosis. The device, powered by a battery, contains a switch allowing selection of the correct waveform for bone growth stimulation or osteoporosis treatment so that, when attached to the skin of the patient using standard skin contact electrodes, the correct signal is communicated to the underlying bone structures. 5 figs.

  2. Optical interference with digital holograms

    NASA Astrophysics Data System (ADS)

    Gossman, David; Perez-Garcia, Benjamin; Hernandez-Aranda, Raul I.; Forbes, Andrew

    2016-07-01

    In 1804, Thomas Young reported the observation of fringes in the intensity of light, and attributed it to the concept of interference between coherent sources. In this paper, we revisit this famous experiment and show how it can easily be demonstrated with digital holography. We look closely at the concept of interference with light and ask, "fringes in what?" We then show that depending on how light interferes, fringe patterns in observables other than intensity can be seen. We explain this conceptually and demonstrate it experimentally. We provide a holistic approach to the topic, aided by modern laboratory practices for a straightforward demonstration of the underlying physics.

  3. High speed quantitative digital microscopy

    NASA Technical Reports Server (NTRS)

    Castleman, K. R.; Price, K. H.; Eskenazi, R.; Ovadya, M. M.; Navon, M. A.

    1984-01-01

    Modern digital image processing hardware makes possible quantitative analysis of microscope images at high speed. This paper describes an application to automatic screening for cervical cancer. The system uses twelve MC6809 microprocessors arranged in a pipeline multiprocessor configuration. Each processor executes one part of the algorithm on each cell image as it passes through the pipeline. Each processor communicates with its upstream and downstream neighbors via shared two-port memory. Thus no time is devoted to input-output operations as such. This configuration is expected to be at least ten times faster than previous systems.

  4. Digital subtraction angiography in children

    SciTech Connect

    Wagner, M.L.; Singleton, E.B.; Egan, M.E.

    1983-01-01

    Preliminary results with digital subtraction angiography in infants and children have shown this to be an excellent screening procedure and often diagnostic. The examination can be performed satisfactorily on outpatients. Sixty patients have undergone this examination for evaluation of suspected abnormalities of the aortic arch and its branches, intracranial arteries, pulmonary arteries, abdominal aorta and its branches, and peripheral vessels. Adequate sedation is mandatory to prevent motion artifacts. While the literature reports increasing use of central venous catheters for delivery of contrast material, the use of short catheters placed in an antecubital vein is satisfactory for the pediatric patient. Techniques of the procedures are described along with seven appropriate case examples.

  5. Digital adaptive flight controller development

    NASA Technical Reports Server (NTRS)

    Kaufman, H.; Alag, G.; Berry, P.; Kotob, S.

    1974-01-01

    A design study of adaptive control logic suitable for implementation in modern airborne digital flight computers was conducted. Two designs are described for an example aircraft. Each of these designs uses a weighted least squares procedure to identify parameters defining the dynamics of the aircraft. The two designs differ in the way in which control law parameters are determined. One uses the solution of an optimal linear regulator problem to determine these parameters while the other uses a procedure called single stage optimization. Extensive simulation results and analysis leading to the designs are presented.

  6. Centralized digital control of accelerators

    SciTech Connect

    Melen, R.E.

    1983-09-01

    In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

  7. Project Gemini online digital archive

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-01-01

    An archive containing the first high-resolution digital scans of the original flight films from Project Gemini, the second U.S. human spaceflight program, was unveiled by the NASA Johnson Space Center and Arizona State University's (ASU) School of Earth and Space Exploration on 6 January. The archive includes images from 10 flights. Project Gemini, which ran from 1964 to 1966, followed Project Mercury and preceded the Apollo spacecraft. Mercury and Apollo imagery are also available through ASU. For more information, see http://tothemoon.ser.asu.edu/gallery/gemini and http://apollo.sese.asu.edu/index.html.

  8. Digital Receiver for Microwave Radiometry

    NASA Technical Reports Server (NTRS)

    Ellingson, Steven W.; Hampson, Grant A.; Johnson, Joel T.

    2005-01-01

    A receiver proposed for use in L-band microwave radiometry (for measuring soil moisture and sea salinity) would utilize digital signal processing to suppress interfering signals. Heretofore, radio frequency interference has made it necessary to limit such radiometry to a frequency band about 20 MHz wide, centered at .1,413 MHz. The suppression of interference in the proposed receiver would make it possible to expand the frequency band to a width of 100 MHz, thereby making it possible to obtain greater sensitivity and accuracy in measuring moisture and salinity

  9. The solan digital sky suvey

    SciTech Connect

    Nash, T.

    1996-01-01

    A description is provided for the planned Sloan Digital Sky Survey (SDSS) designed to replace and supplement the Palomar Sky Survey used broadly in cosmology for the past four decades. The SDSS will employ CCD detectors to achieve orders of magnitude increases sensitivity over photographic plates used in the Palomar survey. Described herein are plans for and expected results to be gained from the survey. Detailed descriptions of the design and construction of the SDSS Telescope at Apache Point Observatory, NM. and the spectrographs to be used are also provided.

  10. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, James W.

    1995-01-01

    A device for stimulating bone tissue by applying a low level alternating current signal directly to the patient's skin. A crystal oscillator, a binary divider chain and digital logic gates are used to generate the desired waveforms that reproduce the natural electrical characteristics found in bone tissue needed for stimulating bone growth and treating osteoporosis. The device, powered by a battery, contains a switch allowing selection of the correct waveform for bone growth stimulation or osteoporosis treatment so that, when attached to the skin of the patient using standard skin contact electrodes, the correct signal is communicated to the underlying bone structures.

  11. High-density digital recording

    NASA Technical Reports Server (NTRS)

    Kalil, F. (Editor); Buschman, A. (Editor)

    1985-01-01

    The problems associated with high-density digital recording (HDDR) are discussed. Five independent users of HDDR systems and their problems, solutions, and insights are provided as guidance for other users of HDDR systems. Various pulse code modulation coding techniques are reviewed. An introduction to error detection and correction head optimization theory and perpendicular recording are provided. Competitive tape recorder manufacturers apply all of the above theories and techniques and present their offerings. The methodology used by the HDDR Users Subcommittee of THIC to evaluate parallel HDDR systems is presented.

  12. High-Speed Digital Interferometry

    NASA Technical Reports Server (NTRS)

    De Vine, Glenn; Shaddock, Daniel A.; Ware, Brent; Spero, Robert E.; Wuchenich, Danielle M.; Klipstein, William M.; McKenzie, Kirk

    2012-01-01

    Digitally enhanced heterodyne interferometry (DI) is a laser metrology technique employing pseudo-random noise (PRN) codes phase-modulated onto an optical carrier. Combined with heterodyne interferometry, the PRN code is used to select individual signals, returning the inherent interferometric sensitivity determined by the optical wavelength. The signal isolation arises from the autocorrelation properties of the PRN code, enabling both rejection of spurious signals (e.g., from scattered light) and multiplexing capability using a single metrology system. The minimum separation of optical components is determined by the wavelength of the PRN code.

  13. Digital Discover of Ephemeral Ponds

    DTIC Science & Technology

    2012-08-01

    ER D C/ CE RL T R - 12 -2 1 Center Directed Research Program Digital Discover of Ephemeral Ponds En gi ne er R es ea rc h an d D ev el...r.mapcalc formula : r.terraflow lidar_elev filled=elev_filled \\ accum=elev_accum memory=2000 \\ dir=elev_dir swater=elev_sink tci =elev_tci...J. D., M. Shapiro, W. D. Goran, and D. P. Gerdes. 1992. Geographic Resources Analysis Support System (GRASS) Version 4.0 User’s Reference Manual . N

  14. Digital Noise Reduction: An Overview

    PubMed Central

    Bentler, Ruth; Chiou, Li-Kuei

    2006-01-01

    Digital noise reduction schemes are being used in most hearing aids currently marketed. Unlike the earlier analog schemes, these manufacturer-specific algorithms are developed to acoustically analyze the incoming signal and alter the gain/output characteristics according to their predetermined rules. Although most are modulation-based schemes (ie, differentiating speech from noise based on temporal characteristics), spectral subtraction techniques are being applied as well. The purpose of this article is to overview these schemes in terms of their differences and similarities. PMID:16959731

  15. 76 FR 11680 - Digital Low Power Television, Television Translator, and Television Booster Stations and Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 73 and 74 Digital Low Power Television, Television Translator, and Television Booster Stations and Digital Class A Television Stations AGENCY: Federal Communications Commission. ACTION:...

  16. Digital Light Processing and MEMS: reflecting the digital display needs of the networked society

    NASA Astrophysics Data System (ADS)

    Hornbeck, Larry J.

    1996-08-01

    Digital video technology is becoming increasingly important to the networked society. The natural interface to digital video is a digital display, one that accepts electrical bits at its input and converts them into optical bits at the output. The digital-to-analog processing function is performed in the mind of the observer. Texas Instruments has developed such a display with its recent market introduction of the Digital Light ProcessingTM (DLPTM) projection display. DLP technology is based on the Digital Micromirror DeviceTM (DMDTM), a microelectromechanical systems (MEMS) array of semiconductor-based digital light switches. The DMD switching array precisely controls a light source for projection display and digital printing applications. This paper presents an overview of DLP technology along with the architecture, projection operation, manufacture, and reliability of the DMD. Features of DMD technology that distinguish it from conventional MEMS technology are explored. Finally, the paper provides a view of DLP business opportunities.

  17. Digital scanner infrared focal plane technology

    NASA Astrophysics Data System (ADS)

    Ortiz, M. A.; Malone, N. R.; Harris, M.; Shin, J.; Byers, S.; Price, D.; Vampola, J.

    2011-09-01

    Advancements in finer geometry and technology advancements in circuit design now allow placement of digital architecture on cryogenic focal planes while using less power than heritage analog designs. These advances in technology reduce the size, weight, and power of modern focal planes. In addition, the interface to the focal plane is significantly simplified and is more immune to Electromagnetic Interference (EMI). The cost of the customer's instrument after integration with the digital scanning Focal Plane Array (FPA) has been significantly reduced by placing digital architecture such as Analog to digital convertors and Low Voltage Differential Signaling (LVDS) Inputs and Outputs (I/O) on the Read Out Integrated Circuit (ROIC).

  18. Digital signal processing for radioactive decay studies

    SciTech Connect

    Miller, D.; Madurga, M.; Paulauskas, S. V.; Ackermann, D.; Heinz, S.; Hessberger, F. P.; Hofmann, S.; Grzywacz, R.; Miernik, K.; Rykaczewski, K.; Tan, H.

    2011-11-30

    The use of digital acquisition system has been instrumental in the investigation of proton and alpha emitting nuclei. Recent developments extend the sensitivity and breadth of the application. The digital signal processing capabilities, used predominately by UT/ORNL for decay studies, include digitizers with decreased dead time, increased sampling rates, and new innovative firmware. Digital techniques and these improvements are furthermore applicable to a range of detector systems. Improvements in experimental sensitivity for alpha and beta-delayed neutron emitters measurements as well as the next generation of superheavy experiments are discussed.

  19. Cooperative Dimensions of a Digitization Project

    ERIC Educational Resources Information Center

    Adaryukov, Andrew

    2004-01-01

    After a brief overview of the digitization activities at Florida Atlantic University Libraries, this article describes one project in detail, concentrating on various types of cooperation it reflects.

  20. Axial Tomography from Digitized Real Time Radiography

    DOE R&D Accomplishments Database

    Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  1. The Process of Digitizing of Old Globe

    NASA Astrophysics Data System (ADS)

    Ambrožová, K.; Havrlanta, J.; Talich, M.; Böhm, O.

    2016-06-01

    This paper describes the process of digitalization of old globes that brings with it the possibility to use globes in their digital form. Created digital models are available to the general public through modern technology in the Internet network. This gives an opportunity to study old globes located in various historical collections, and prevent damage of the originals. Another benefit of digitization is also a possibility of comparing different models both among themselves and with current map data by increasing the transparency of individual layers. Digitization is carried out using special device that allows digitizing globes with a diameter ranging from 5 cm to 120 cm. This device can be easily disassembled, and it is fully mobile therefore the globes can be digitized in the place of its storage. Image data of globe surface are acquired by digital camera firmly fastened to the device. Acquired image data are then georeferenced by using a method of complex adjustment. The last step of digitization is publication of the final models that is realized by two ways. The first option is in the form of 3D model through JavaScript library Cesium or Google Earth plug-in in the Web browser. The second option is as a georeferenced map using Tile Map Service.

  2. Automatic color map digitization by spectral classification

    NASA Technical Reports Server (NTRS)

    Chu, N. Y.; Anuta, P. E.

    1979-01-01

    A method of converting polygon map information into a digital form which does not require manual tracing of polygon edges is discussed. The maps must be in color-coded format with a unique color for each category in the map. Color scanning using a microdensitometer is employed and a three-channel color separation digital data set is generated. The digital data are then classified by using a Gaussian maximum likelihood classifier, and the resulting digitized map is evaluated. Very good agreement is observed between the classified and original map.

  3. Tracing the evolution of avian wing digits.

    PubMed

    Xu, Xing; Mackem, Susan

    2013-06-17

    It is widely accepted that birds are a subgroup of dinosaurs, but there is an apparent conflict: modern birds have been thought to possess only the middle three fingers (digits II-III-IV) of an idealized five-digit tetrapod hand based on embryological data, but their Mesozoic tetanuran dinosaur ancestors are considered to have the first three digits (I-II-III) based on fossil evidence. How could such an evolutionary quirk arise? Various hypotheses have been proposed to resolve this paradox. Adding to the confusion, some recent developmental studies support a I-II-III designation for avian wing digits whereas some recent paleontological data are consistent with a II-III-IV identification of the Mesozoic tetanuran digits. A comprehensive analysis of both paleontological and developmental data suggests that the evolution of the avian wing digits may have been driven by homeotic transformations of digit identity, which are more likely to have occurred in a partial and piecemeal manner. Additionally, recent genetic studies in mouse models showing plausible mechanisms for central digit loss invite consideration of new alternative possibilities (I-II-IV or I-III-IV) for the homologies of avian wing digits. While much progress has been made, some advances point to the complexity of the problem and a final resolution to this ongoing debate demands additional work from both paleontological and developmental perspectives, which will surely yield new insights on mechanisms of evolutionary adaptation.

  4. Digital Perspective Correction For Cylindrical Holographic Stereograms

    NASA Astrophysics Data System (ADS)

    Jaffey, Stephen M.; Dutta, Kalyan

    1983-04-01

    This paper discusses digital perspective correction in the multiplex hologram,also known as Cross hologram or white light cylindrical holographic stereogram. It presents digital analogues of previously reported optical methods, and demonstrates the digital implementation of Benton's method. It introduces a non-linear remapping of the input views to compensate for a non-uniform color viewing position. Simulation results are included on the relative accuracy of different algorithms. Digital correction can be applied to both real and artificial objects such as computed tomography (CT) data.

  5. Parallel Digital Phase-Locked Loops

    NASA Technical Reports Server (NTRS)

    Sadr, Ramin; Shah, Biren N.; Hinedi, Sami M.

    1995-01-01

    Wide-band microwave receivers of proposed type include digital phase-locked loops in which band-pass filtering and down-conversion of input signals implemented by banks of multirate digital filters operating in parallel. Called "parallel digital phase-locked loops" to distinguish them from other digital phase-locked loops. Systems conceived as cost-effective solution to problem of filtering signals at high sampling rates needed to accommodate wide input frequency bands. Each of M filters process 1/M of spectrum of signal.

  6. Digital Image Compression Using Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Serra-Ricart, M.; Garrido, L.; Gaitan, V.; Aloy, A.

    1993-01-01

    The problem of storing, transmitting, and manipulating digital images is considered. Because of the file sizes involved, large amounts of digitized image information are becoming common in modern projects. Our goal is to described an image compression transform coder based on artificial neural networks techniques (NNCTC). A comparison of the compression results obtained from digital astronomical images by the NNCTC and the method used in the compression of the digitized sky survey from the Space Telescope Science Institute based on the H-transform is performed in order to assess the reliability of the NNCTC.

  7. Digitally encoded all-optical sensor multiplexing

    NASA Astrophysics Data System (ADS)

    Pervez, Anjum

    1992-01-01

    A digital, all-optical temperature sensor design concept based on optical sampling and digital encoding is presented. The proposed sensor generates 2M binary digital codewords of length M bits. The codewords are generated serially and, therefore, only a single output fiber line is required. A multiplexing scheme, which minimizes the power requirement per sensor array and facilitates a cost-effective digit regeneration for remote monitoring over long distance, is presented. The sensor arrays are used as building blocks to configure large scale sensor networks based on LAN topologies.

  8. Digital imaging applications in anatomic pathology.

    PubMed

    Leong, F Joel W-M; Leong, Anthony S-Y

    2003-03-01

    Digital imaging has progressed at a rapid rate and is likely to eventually replace chemical photography in most areas of professional and amateur digital image acquisition. In pathology, digital microscopy has implications beyond that of taking a photograph. The arguments for adopting this new medium are compelling, and given similar developments in other areas of pathology and radiologic imaging, acceptance of the digital medium should be viewed as a component of the technological evolution of the laboratory. A digital image may be stored, replicated, catalogued, employed for educational purposes, transmitted for further interpretation (telepathology), analyzed for salient features (medical vision/image analysis), or form part of a wider digital healthcare strategy. Despite advances in digital camera technology, good image acquisition still requires good microscope optics and the correct calibration of all system components, something which many neglect. The future of digital imaging in pathology is very promising and new applications in the fields of automated quantification and interpretation are likely to have profound long-term influence on the practice of anatomic pathology. This paper discusses the state of the art of digital imaging in anatomic pathology.

  9. Axial tomography from digitized real time radiography

    SciTech Connect

    Zolnay, A.S.; McDonald, W.M.; Doupont, P.A.; McKinney, R.L.; Lee, M.M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  10. Pseudolog Digital-to-Analog Converter

    NASA Technical Reports Server (NTRS)

    Gooder, S. T.

    1986-01-01

    Sensitivity decreases by 10 at beginning of each input decade. Method conceived to convert binary-coded data to suitable linear form for stripchart recording. Strip-chart recordings obtained from typical pressure readings in a vacuum system during pumpdown. In reading curve, BCD digital vacuum-gage output processed by analog-to-digital converter in such way that only reading digits (but not range) appear in output. In range and reading, range also converted to analog and placed as most significant digit.

  11. New Roles for New Times: Digital Curation for Preservation

    ERIC Educational Resources Information Center

    Walters, Tyler; Skinner, Katherine

    2011-01-01

    Digital curation refers to the actions people take to maintain and add value to digital information over its lifecycle, including the processes used when creating digital content. Digital preservation focuses on the "series of managed activities necessary to ensure continued access to digital materials for as long as necessary." In this…

  12. Electronics. Module 3: Digital Logic Application. Instructor's Guide.

    ERIC Educational Resources Information Center

    Carter, Ed; Murphy, Mark

    This guide contains instructor's materials for a 10-unit secondary school course on digital logic application. The units are introduction to digital, logic gates, digital integrated circuits, combination logic, flip-flops, counters and shift registers, encoders and decoders, arithmetic circuits, memory, and analog/digital and digital/analog…

  13. Digital Control Of A Telescope In An Airplane

    NASA Technical Reports Server (NTRS)

    Mccormack, Ann C.; Snyder, Philip K.

    1991-01-01

    Options for design of aim-stabilizing system analyzed. Report discusses feasibility of digital control system stabilizing aim of 30-in. telescope aboard NASA C141 airplane known as Kuiper Atmospheric Observatory. Proposed digital compensator consists of input analog-to-digital converter, digital controller processor, and output digital-to-analog converter.

  14. Digital subtraction angiography of the heart and lungs

    SciTech Connect

    Moodie, D.S.; Yiannikas, J.

    1986-01-01

    This book contains 12 chapters. Some of the chapter titles are: Physical Principles of Cardiac Digital Subtraction Angiography, The Use of Intravenous Digital Subtraction Angiography in Evaluating Patients with Complex Congenital Heart Disease, Exercise Intravenous Digital Subtraction Angiograpny, Cardiomyopathic and Cardiac Neoplastic Disease, Digital Subtraction Angiography in the Catheterization Laboratory, and Cardiac Digital Subtraction Angiography - Future Directions.

  15. Characterization of a 16-Bit Digitizer for Lidar Data Acquisition

    NASA Technical Reports Server (NTRS)

    Williamson, Cynthia K.; DeYoung, Russell J.

    2000-01-01

    A 6-MHz 16-bit waveform digitizer was evaluated for use in atmospheric differential absorption lidar (DIAL) measurements of ozone. The digitizer noise characteristics were evaluated, and actual ozone DIAL atmospheric returns were digitized. This digitizer could replace computer-automated measurement and control (CAMAC)-based commercial digitizers and improve voltage accuracy.

  16. Current State of Digital Reference in Primary and Secondary Education; The Technological Challenges of digital Reference; Question Negotiation and the Technological Environment; Evaluation of Chat Reference Service Quality; Visual Resource Reference: Collaboration between Digital Museums and Digital Libraries.

    ERIC Educational Resources Information Center

    Lankes, R. David; Penka, Jeffrey T.; Janes, Joseph; Silverstein, Joanne; White, Marilyn Domas; Abels, Eileen G.; Kaske, Neal; Goodrum, Abby A.

    2003-01-01

    Includes five articles that discuss digital reference in elementary and secondary education; the need to understand the technological environment of digital reference; question negotiation in digital reference; a pilot study that evaluated chat reference service quality; and collaborative digital museum and digital library reference services. (LRW)

  17. Preservation in the Age of Google: Digitization, Digital Preservation, and Dilemmas

    ERIC Educational Resources Information Center

    Conway, Paul

    2010-01-01

    The cultural heritage preservation community now functions largely within the environment of digital technologies. This article begins by juxtaposing definitions of the terms "digitization for preservation" and "digital preservation" within a sociotechnical environment for which Google serves as a relevant metaphor. It then reviews two reports…

  18. 75 FR 63766 - Digital Low Power Television, Television Translator, and Television Booster Stations and Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... COMMISSION 47 CFR Parts 73 and 74 Digital Low Power Television, Television Translator, and Television Booster Stations and Digital Class A Television Stations AGENCY: Federal Communications Commission. ACTION... that need to be resolved to complete the low power television station digital transition....

  19. Digital Competence at the Beginning of Upper Secondary School: Identifying Factors Explaining Digital Inclusion

    ERIC Educational Resources Information Center

    Hatlevik, Ove Edvard; Christophersen, Knut-Andreas

    2013-01-01

    During the last decade, information and communication technology has been given an increasingly large importance in our society. There seems to be a consensus regarding the necessity of supporting and developing school-based digital competence. In order to sustain digital inclusion, schools need to identify digital deficiencies and digital…

  20. Preserving Digital Information. Report of the Task Force on Archiving of Digital Information.

    ERIC Educational Resources Information Center

    Waters, Donald; Garrett, John

    The 21-member Task Force on Archiving of Digital Information was formed in December 1994 and spent a year studying what is needed to make digital libraries stable, accessible, and valid. Their final report is divided into the following sections: (1) "Introduction," which examines the fragility of cultural memory in a digital age and the…