47 CFR 8.5 - No blocking.

Code of Federal Regulations, 2012 CFR

2012-10-01

... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.5 No blocking. (a) A person engaged in the provision of fixed broadband Internet access service, insofar as such person is so engaged... network management. (b) A person engaged in the provision of mobile broadband Internet access service...

47 CFR 8.5 - No blocking.

Code of Federal Regulations, 2014 CFR

2014-10-01

... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.5 No blocking. (a) A person engaged in the provision of fixed broadband Internet access service, insofar as such person is so engaged... network management. (b) A person engaged in the provision of mobile broadband Internet access service...

47 CFR 8.5 - No Blocking.

Code of Federal Regulations, 2011 CFR

2011-10-01

... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.5 No Blocking. (a) A person engaged in the provision of fixed broadband Internet access service, insofar as such person is so engaged... network management. (b) A person engaged in the provision of mobile broadband Internet access service...

Exploring the Digital Nation: Home Broadband Internet Adoption in the United States

ERIC Educational Resources Information Center

National Telecommunications and Information Administration, 2010

2010-01-01

The Internet has revolutionized the social and economic environment in which people live by providing an alternative or supplemental channel for communication, gathering and disseminating information, entertainment, commerce, and education. Household use of high-speed, or broadband, Internet services has risen dramatically during this decade which…

Telecommunications: Characteristics and Choices of Internet Users. Report to the Ranking Minority Member, Subcommittee on Telecommunications, Committee on Energy and Commerce, House of Representatives.

ERIC Educational Resources Information Center

Czerwinski, Stanley J.

This study examined the demographic characteristics of Internet users compared with those of the general U.S. population, the characteristics of areas where broadband Internet transport is available and of consumers who selected a broadband transport provider, and the factors influencing consumers' choice of an ISP (Internet service provider) and…

Community-Based Broadband Solutions: The Benefits of Competition and Choice for Community Development and Highspeed Internet Access

ERIC Educational Resources Information Center

Executive Office of the President, 2015

2015-01-01

Affordable, reliable access to high speed broadband is critical to U.S. economic growth and competitiveness. Upgrading to higher-speed broadband lets consumers use the Internet in new ways, increases the productivity of American individuals and businesses, and drives innovation throughout the digital ecosystem. As this report describes, while the…

Rural Broadband at a Glance: 2009 Edition. Economic Information Bulletin Number 47

ERIC Educational Resources Information Center

US Department of Agriculture, 2009

2009-01-01

Three-quarters of U.S. residents used the Internet to access information, education, and services in 2007. Widespread Internet adoption suggests it has great value to individuals, businesses, and communities. Broadband Internet access is becoming essential for both businesses and households; many compare its evolution to other technologies now…

75 FR 29516 - Broadband Researchers' Data Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-26

... Population Survey Computer and Internet Use Supplement survey instrument (pp. 8 through 23), http://www.bls... adoption. Current and detailed data by U.S. households' and persons' usage of and access to broadband is... propose, with rationale, the type of Internet usage data that could be usefully collected through...

Broadband for Public Libraries: Importance, Issues, and Research Needs

ERIC Educational Resources Information Center

Mandel, Lauren H.; Bishop, Bradley Wade; McClure, Charles R.; Bertot, John Carlo; Jaeger, Paul T.

2010-01-01

U.S. public libraries provide free public internet services to the communities that they serve, but require robust, high-speed broadband internet connections to continue meeting public demands. The 2008-2009 "Public Library Funding & Technology Access Study" ("PLFTAS") illustrates challenges that public libraries encounter in achieving broadband…

Examining Factors Influencing the Behavioral Intention to Adopt Broadband in Malaysia

NASA Astrophysics Data System (ADS)

Dwivedi, Yogesh K.; Selamat, Mohamad H.; Wahab, Muhammad S. Abd; Samsudin, Mohd A. Mat; Lal, Banita

The aim of this study was to examine the factors affecting the adoption of broadband Internet in a developing country context by focusing upon Malaysia. The data relating to these factors was collected using a survey approach. The findings of this paper suggest that perceived usefulness, perceived ease of use, and social influence are significant factors for explaining the behavioral intention to adopt broadband Internet by Malaysian accountants. The paper proceeds to outline the research limitations, theoretical contributions, and implications for practice.

75 FR 36071 - Framework for Broadband Internet Service

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-24

... contractor, Best Copy and Printing, Inc. (BCPI), Portals II, 445 12th Street, SW., Room CY-B402, Washington...-leading high-speed broadband networks--both wired and wireless--lies at the very core of the FCC's mission... subscribers with high-speed Internet access, as well as many applications or functions that can be used with...

Using TV white space spectrum to practise telemedicine: A promising technology to enhance broadband internet connectivity within healthcare facilities in rural regions of developing countries.

PubMed

Chavez, Afton; Littman-Quinn, Ryan; Ndlovu, Kagiso; Kovarik, Carrie L

2016-06-01

The following correspondence provides an overview of TV White Space (TVWS) technology, regulations, and potential applications to the health care sector. This report also introduces "Project Kgolagano," a Botswana-based initiative representing the first endeavour to utilize TVWS internet connection for practising telemedicine. TV "white space" refers to the previously unused, wasted spectrum within TV radiofrequency channels that can now be leveraged to obtain broadband internet access. TVWS represents a less costly, faster, and farther-reaching internet connection that is a promising option for connecting the previously unconnected populations of remote and underserved areas. The Botswana-University of Pennsylvania Partnership, Microsoft, Botswana Innovation Hub, Vista Life Sciences, and Global Broadband Solutions have partnered together to bring TVWS wireless broadband access to healthcare facilities in poorly connected regions of Botswana (Lobatse, Francistown, Maun, Gaborone) in order to improve healthcare delivery and facilitate telemedicine in dermatology, cervical cancer screening, and family medicine (HIV/AIDS, TB, general adult and pediatric medicine). © The Author(s) 2015.

Progress on Broadband Access to the Internet and Use of Mobile Devices in the United States.

PubMed

Serrano, Katrina J; Thai, Chan L; Greenberg, Alexandra J; Blake, Kelly D; Moser, Richard P; Hesse, Bradford W

Healthy People 2020 (HP2020) aims to improve population health outcomes through several objectives, including health communication and health information technology. We used 7 administrations of the Health Information National Trends Survey to examine HP2020 goals toward access to the Internet through broadband and mobile devices (N = 34 080). We conducted descriptive analyses and obtained predicted marginals, also known as model-adjusted risks, to estimate the association between demographic characteristics and use of mobile devices. The HP2020 target (7.7% of the US population) for accessing the Internet through a cellular network was surpassed in 2014 (59.7%), but the HP2020 target (83.2%) for broadband access fell short (63.8%). Sex and age were associated with accessing the Internet through a cellular network throughout the years (Wald F test, P <.05). The increase in the percentage of people accessing the Internet through mobile devices presents an opportunity for technology-based health interventions that should be explored.

Progress on Broadband Access to the Internet and Use of Mobile Devices in the United States

PubMed Central

Thai, Chan L.; Greenberg, Alexandra J.; Blake, Kelly D.; Moser, Richard P.; Hesse, Bradford W.

2016-01-01

Healthy People 2020 (HP2020) aims to improve population health outcomes through several objectives, including health communication and health information technology. We used 7 administrations of the Health Information National Trends Survey to examine HP2020 goals toward access to the Internet through broadband and mobile devices (N = 34 080). We conducted descriptive analyses and obtained predicted marginals, also known as model-adjusted risks, to estimate the association between demographic characteristics and use of mobile devices. The HP2020 target (7.7% of the US population) for accessing the Internet through a cellular network was surpassed in 2014 (59.7%), but the HP2020 target (83.2%) for broadband access fell short (63.8%). Sex and age were associated with accessing the Internet through a cellular network throughout the years (Wald F test, P <.05). The increase in the percentage of people accessing the Internet through mobile devices presents an opportunity for technology-based health interventions that should be explored. PMID:28005473

The digital divide: Trends in global mobile and broadband Internet access from 2000–2010

PubMed Central

Ronquillo, Charlene; Currie, Leanne

2012-01-01

The digital divide is described as the gap between those who do and do not have access to digital information and communications technologies (ICT). ICTs are viewed as an indicator of infrastructure and potential for development, and are a growing platform for health information and services delivery. This study compares the penetration of mobile and broadband Internet technologies by global region from 2000 to 2010. Results illustrate the rapid growth of mobile cellular telephone subscriptions in all global regions with trends suggesting a continued increase. Little to modest gains were made in fixed broadband Internet subscriptions globally. There is a growing popularity of mobile subscriptions with use of data communications, exceeding the numbers of fixed Internet subscriptions. This comparison reveals current strengths that can be built on and highlights the importance of awareness of global trends and using such knowledge to inform design and delivery of ICT-based health services. PMID:24199118

Residential Broadband Access for Students at Walters State Community College

ERIC Educational Resources Information Center

Hurst, Mark A.

2010-01-01

The purpose of this study was to determine the availability of internet access for students attending Walters State Community College during the spring semester 2010. In particular, it is unknown to what degree broadband internet access is available in the counties that Walters State considers the service area of the college. The research was…

2012 Minnesota Internet Survey: Digital Divide 2.0 and Beyond

ERIC Educational Resources Information Center

Center for Rural Policy and Development, 2012

2012-01-01

After more than ten years of asking rural Minnesotans about their access to high-speed Internet service, it is possible to draw a few conclusions: (1) It is fairly well accepted now that broadband access has become a necessity for functioning at full capacity in today's world; (2) The digital divide isn't what it used to be; (3) Broadband no…

The U.S. Market For Broadband Over Powerline, 3. edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2007-07-15

The report provides a study of the potential market for BPL technology in the U.S. including a look at the past, present, and future state of Broadband Over Powerline (BPL) in the U.S. The Scope of the report includes the following topics: a description of the history of powerline communications (PLC) and broadband over powerline (BPL) technology; an analysis of key drivers of BPL within the electric utility and internet access industries; an overview of BPL technology and architecture; a comparison of BPL with alternative broadband access methods; an analysis of technological, regulatory, and business barriers to BPL's success; identificationmore » of the key applications and markets for BPL; a description of business models for BPL; an analysis of key market trends in broadband internet access; a review of the market development of cable modem broadband access; profiles of major U.S. BPL market participants; and, profiles of major U.S. BPL projects.« less

75 FR 28781 - Proposed Information Collection; Comment Request; Broadband Subscription and Usage Supplement to...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-24

... Information Collection; Comment Request; Broadband Subscription and Usage Supplement to the Census Bureau's Current Population Survey AGENCY: National Telecommunications and Information Administration. ACTION... Population Survey (CPS) in order to gather reliable data on broadband (also known as high-speed Internet) use...

A Mixed Method Case Study Investigation of the Digital Divide in West Virginia: Residential Broadband Saturation Levels and Obstacles to Adoption

ERIC Educational Resources Information Center

Lee, Anna M.

2013-01-01

In recent decades Internet usage as a ready service in the home has become an assumed part of everyday life for most Americans. There are, however, some without residential broadband Internet service. The literature defined this circumstance as the digital divide, a phenomena that was reportedly receding, but was a greater issue in rural areas of…

Municipal Broadband in Wilson, North Carolina: A Study

ERIC Educational Resources Information Center

O'Boyle, Timothy

2012-01-01

Relatively little empirical attention has been paid to the political economy of publicly-retailed fiber-optic broadband internet service. To address this gap in the literature, this dissertation examines the history, dynamics and trends in the municipal broadband movement. In specific, Wilson, North Carolina's Greenlight service is examined in…

"SWING": A European project for a new application of an ionospheric network

NASA Astrophysics Data System (ADS)

Zolesi, B.; Bianchi, C.; Meloni, A.; Baskaradas, J. A.; Belehaki, A.; Altadill, D.; Dalle Mese, E.

2016-05-01

The SWING (Short Wave critical Infrastructure Network based on a new Generation high survival radio communication system) is a European project aimed at studying a high survival high-frequency (HF) radio network to link European Critical Infrastructures (ECIs). This system is thought to replace broadband internet communication, maintaining the minimum flux of essential information for the ECIs management and control, in case of wide-scale threats, including terrorist attacks, able to put out of order internet links over the Mediterranean region. SWING is designed to evaluate the threat and increase the security awareness, as well as the level of protection, of analogous and/or interdependent ECIs. In order to meet these goals, SWING was finalized to recognize how and when the internet communication fails and to develop the standard software and hardware tools necessary for implementing communication protocols suited for a reliable and interoperable short-wave (SW) or high-frequency (HF) radio network backup. The internet broadband description and internet failure recognition were taken into consideration in the project but are not treated in this paper. It has been assessed that in case of complete failure of the internet broadband communication fundamental information for the management and control of ECIs over the Mediterranean region can be maintained with a HF network, even in case of moderate ionospheric perturbations.

Architectural and Mobility Management Designs in Internet-Based Infrastructure Wireless Mesh Networks

ERIC Educational Resources Information Center

Zhao, Weiyi

2011-01-01

Wireless mesh networks (WMNs) have recently emerged to be a cost-effective solution to support large-scale wireless Internet access. They have numerous applications, such as broadband Internet access, building automation, and intelligent transportation systems. One research challenge for Internet-based WMNs is to design efficient mobility…

Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system.

PubMed

Johansson, Johannes D; Mireles, Miguel; Morales-Dalmau, Jordi; Farzam, Parisa; Martínez-Lozano, Mar; Casanovas, Oriol; Durduran, Turgut

2016-02-01

A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in height. The system has been validated with liquid phantoms, demonstrated in vivo on a human fingertip during an arm cuff occlusion and on a group of mice with xenoimplanted renal cell carcinoma.

47 CFR 8.9 - Other laws and considerations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.9 Other laws and... Internet access service may have to address the needs of emergency communications or law enforcement... provider of broadband Internet access service to address copyright infringement or other unlawful activity. ...

47 CFR 8.9 - Other laws and considerations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.9 Other laws and... Internet access service may have to address the needs of emergency communications or law enforcement... provider of broadband Internet access service to address copyright infringement or other unlawful activity. ...

47 CFR 8.9 - Other laws and considerations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.9 Other laws and... Internet access service may have to address the needs of emergency communications or law enforcement... provider of broadband Internet access service to address copyright infringement or other unlawful activity. ...

47 CFR 8.9 - Other Laws and Considerations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.9 Other Laws and... Internet access service may have to address the needs of emergency communications or law enforcement... provider of broadband Internet access service to address copyright infringement or other unlawful activity. ...

Broadband set-top box using MAP-CA processor

NASA Astrophysics Data System (ADS)

Bush, John E.; Lee, Woobin; Basoglu, Chris

2001-12-01

Advances in broadband access are expected to exert a profound impact in our everyday life. It will be the key to the digital convergence of communication, computer and consumer equipment. A common thread that facilitates this convergence comprises digital media and Internet. To address this market, Equator Technologies, Inc., is developing the Dolphin broadband set-top box reference platform using its MAP-CA Broadband Signal ProcessorT chip. The Dolphin reference platform is a universal media platform for display and presentation of digital contents on end-user entertainment systems. The objective of the Dolphin reference platform is to provide a complete set-top box system based on the MAP-CA processor. It includes all the necessary hardware and software components for the emerging broadcast and the broadband digital media market based on IP protocols. Such reference design requires a broadband Internet access and high-performance digital signal processing. By using the MAP-CA processor, the Dolphin reference platform is completely programmable, allowing various codecs to be implemented in software, such as MPEG-2, MPEG-4, H.263 and proprietary codecs. The software implementation also enables field upgrades to keep pace with evolving technology and industry demands.

Space information technologies: future agenda

NASA Astrophysics Data System (ADS)

Flournoy, Don M.

2005-11-01

Satellites will operate more like wide area broadband computer networks in the 21st Century. Space-based information and communication technologies will therefore be a lot more accessible and functional for the individual user. These developments are the result of earth-based telecommunication and computing innovations being extended to space. The author predicts that the broadband Internet will eventually be available on demand to users of terrestrial networks wherever they are. Earth and space communication assets will be managed as a single network. Space networks will assure that online access is ubiquitous. No matter whether users are located in cities or in remote locations, they will always be within reach of a node on the Internet. Even today, scalable bandwidth can be delivered to active users when moving around in vehicles on the ground, or aboard ships at sea or in the air. Discussion of the innovative technologies produced by NASA's Advanced Communications Technology Satellite (1993-2004) demonstrates future capabilities of satellites that make them uniquely suited to serve as nodes on the broadband Internet.

Energy diffusion controlled reaction rate of reacting particle driven by broad-band noise

NASA Astrophysics Data System (ADS)

Deng, M. L.; Zhu, W. Q.

2007-10-01

The energy diffusion controlled reaction rate of a reacting particle with linear weak damping and broad-band noise excitation is studied by using the stochastic averaging method. First, the stochastic averaging method for strongly nonlinear oscillators under broad-band noise excitation using generalized harmonic functions is briefly introduced. Then, the reaction rate of the classical Kramers' reacting model with linear weak damping and broad-band noise excitation is investigated by using the stochastic averaging method. The averaged Itô stochastic differential equation describing the energy diffusion and the Pontryagin equation governing the mean first-passage time (MFPT) are established. The energy diffusion controlled reaction rate is obtained as the inverse of the MFPT by solving the Pontryagin equation. The results of two special cases of broad-band noises, i.e. the harmonic noise and the exponentially corrected noise, are discussed in details. It is demonstrated that the general expression of reaction rate derived by the authors can be reduced to the classical ones via linear approximation and high potential barrier approximation. The good agreement with the results of the Monte Carlo simulation verifies that the reaction rate can be well predicted using the stochastic averaging method.

Patient portals and broadband internet inequality.

PubMed

Perzynski, Adam T; Roach, Mary Joan; Shick, Sarah; Callahan, Bill; Gunzler, Douglas; Cebul, Randall; Kaelber, David C; Huml, Anne; Thornton, John Daryl; Einstadter, Douglas

2017-09-01

Patient portals have shown potential for increasing health care quality and efficiency. Internet access and other factors influencing patient portal use could worsen health disparities. Observational study of adults with 1 or more visits to the outpatient clinics of an urban public health care system from 2012 to 2015. We used mixed effects logistic regression to evaluate the association between broadband internet access and (1) patient portal initiation (whether a patient logged in at least 1 time) and (2) messaging, controlling for demographic and neighborhood characteristics. There were 243 248 adults with 1 or more visits during 2012-2015 and 70 835 (29.1%) initiated portal use. Portal initiation was 34.1% for whites, 23.4% for blacks, and 23.8% for Hispanics, and was lower for Medicaid (26.5%), Medicare (23.4%), and uninsured patients (17.4%) than commercially insured patients (39.3%). In multivariate analysis, both initiation of portal use (odds ratio [OR] = 1.24 per quintile, 95% confidence interval [CI], 1.23-1.24, P  < .0001) and sending messages to providers (OR = 1.15, 95%CI, 1.09-1.14, P  < .0001) were associated with neighborhood broadband internet access. The majority of adults with outpatient visits to a large urban health care system did not use the patient portal, and initiation of use was lower for racial and ethnic minorities, persons of lower socioeconomic status, and those without neighborhood broadband internet access. These results suggest the emergence of a digital divide in patient portal use. Given the scale of investment in patient portals and other internet-dependent health information technologies, efforts are urgently needed to address this growing inequality. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Statistics of multiply scattered broadband terahertz pulses.

PubMed

Pearce, Jeremy; Jian, Zhongping; Mittleman, Daniel M

2003-07-25

We describe the first measurements of the diffusion of broadband single-cycle optical pulses through a highly scattering medium. Using terahertz time-domain spectroscopy, we measure the electric field of a multiply scattered wave with a time resolution shorter than one optical cycle. This time-domain measurement provides information on the statistics of both the amplitude and phase distributions of the diffusive wave. We develop a theoretical description, suitable for broadband radiation, which adequately describes the experimental results.

Thyroid tissue constituents characterization and application to in vivo studies by broadband (600-1200 nm) diffuse optical spectroscopy

NASA Astrophysics Data System (ADS)

Konugolu Venkata Sekar, Sanathana; Farina, Andrea; dalla Mora, Alberto; Taroni, Paola; Lindner, Claus; Mora, Mireia; Farzam, Parisa; Pagliazzi, Marco; Squarcia, Mattia; Halperin, Irene; Hanzu, Felicia A.; Dehghani, Hamid; Durduran, Turgut; Pifferi, Antonio

2017-07-01

We present the first broadband (600-1100 nm) diffuse optical characterization of thyroglobulin and tyrosine, which are thyroid-specific tissue constituents. In-vivo measurements at the thyroid region enabled their quantification for functional and diagnostic applications.

7 CFR 1739.12 - Eligible grant purposes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Community Center that furnishes free access to broadband Internet service, provided that the Community... the use of the Internet, not to exceed $15,000 per year. (2) The operating costs to be funded by the...

7 CFR 1739.12 - Eligible grant purposes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Community Center that furnishes free access to broadband Internet service, provided that the Community... the use of the Internet, not to exceed $15,000 per year. (2) The operating costs to be funded by the...

7 CFR 1739.12 - Eligible grant purposes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Community Center that furnishes free access to broadband Internet service, provided that the Community... the use of the Internet, not to exceed $15,000 per year. (2) The operating costs to be funded by the...

7 CFR 1739.12 - Eligible grant purposes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Community Center that furnishes free access to broadband Internet service, provided that the Community... the use of the Internet, not to exceed $15,000 per year. (2) The operating costs to be funded by the...

76 FR 22103 - The Consumer and Governmental Affairs Bureau Seeks Comment on “Need for Speed” Information for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-20

... to make informed choices among competing broadband Internet access services. According to the most... speed and performance required for the range of Internet applications consumers intend to use, and how... electronically using the Internet by accessing the Commission's Electronic Comment Filing System (ECFS): http...

78 FR 14920 - Earth Stations Aboard Aircraft Communicating With Fixed-Satellite Service Geostationary-Orbit...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

... broadband services, including Internet access, to passengers and flight crews aboard commercial airliners... available for download over the Internet at http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-12-161A1...

Mastering the broadband challenge: next-generation SONET in a packet world

NASA Astrophysics Data System (ADS)

Farhi, Eyal

2001-10-01

The continuing liberalization of the world's telecommunications markets and the progressive convergence of voice, data, video and Internet communication are prompting telecommunication service providers to both expand and enhance their service capabilities. As bandwidth-hungry applications proliferate, and the demand for data and data services grows, the requirement for broadband communications appears to be insatiable. To provide the expected level of service in this environment of rapidly increasing demand, telcos and service providers must invest in an expanded network. However, to remain competitive and profitable, they must also continue to leverage their existing infrastructure investment. This paper will examine the current challenges network operators are facing today with the deployment of broadband technologies as they strive to maintain existing infrastructure investments while providing new services to their customers and developing added value network operations. This paper will explore various broadband technologies (optical/wireless) that operate on the primary SDH/SONET standards, their topologies and inherent benefits, which provide operators with solutions to the broadband challenge. New customer demands, such as high-speed Data transmissions (increased Internet use), coupled with operators' continuous need for network optimization, have thrown a wrench into daily operations. Therefore, the need to modernize existing networks has become paramount.

Expanding Access

ERIC Educational Resources Information Center

Roach, Ronald

2007-01-01

There is no question that the United States lags behind most industrialized nations in consumer access to broadband Internet service. For many policy makers and activists, this shortfall marks the latest phase in the struggle to overcome the digital divide. To remedy this lack of broadband affordability and availability, one start-up firm--with…

The Glenview Model: Community Networking via Broadband Cable.

ERIC Educational Resources Information Center

Mundt, John P.

This paper describes the installation of a data network in the community of Glenview, Illinois, which uses broadband cable equipment to connect schools, libraries, and governmental agencies to each other and to the Internet via a high speed Ethernet network. The history of the project is outlined followed by a discussion of the implementation of…

A Blueprint for Big Broadband. An EDUCAUSE White Paper

ERIC Educational Resources Information Center

Windhausen, John, Jr.

2008-01-01

This white paper proposes bringing the federal government, state governments, and the private sector together as part of a new approach to making high-speed Internet services available across the country. It proposes the creation of a new federal Universal Broadband Fund (UBF) that, together with matching funds from the states and the private…

Broadband Access for Students at East Tennessee State University

ERIC Educational Resources Information Center

Sawyer, Thomas Scott

2013-01-01

The purpose of this study was to determine the availability of Internet access for students attending East Tennessee State University during the fall semester 2013. It has been unknown to what degree broadband access is available in the East Tennessee State University service area that includes counties in East Tennessee, Southwest Virginia, and…

Latest Trends in Home Networking Technologies

NASA Astrophysics Data System (ADS)

Tsutsui, Akihiro

Broadband access service, including FTTH, is now in widespread use in Japan. More than half of the households that have broadband Internet access construct local area networks (home networks) in their homes. In addition, information appliances such as personal computers, networked audio, and visual devices and game machines are connected to home networks, and many novel service applications are provided via the Internet. However, it is still difficult to install and incorporate these devices and services because networked devices have been developed in different communities. I briefly explain the current status of information appliances and home networking technologies and services and discuss some of the problems in this and their solutions.

3 CFR - Unleashing the Wireless Broadband Revolution

Code of Federal Regulations, 2011 CFR

2011-01-01

... Internet, as vital infrastructure, has become central to the daily economic life of almost every American..., and improve the quality of our lives as wireless high-speed access to the Internet. Innovative new... applications that will transform Americans' lives. Spectrum and the new technologies it enables also are...

47 CFR 20.20 - Conditions applicable to provision of CMRS service by incumbent Local Exchange Carriers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... terms and conditions of the transaction on the Internet within 10 days of the transaction through the... Radio Service (Broadband CMRS). For the purposes of this section, “broadband CMRS” means Cellular Radiotelephone Service (part 22, subpart H of this chapter), Specialized Mobile Radio (part 90, subpart S of this...

47 CFR 20.20 - Conditions applicable to provision of CMRS service by incumbent Local Exchange Carriers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... terms and conditions of the transaction on the Internet within 10 days of the transaction through the... Radio Service (Broadband CMRS). For the purposes of this section, “broadband CMRS” means Cellular Radiotelephone Service (part 22, subpart H of this chapter), Specialized Mobile Radio (part 90, subpart S of this...

47 CFR 20.20 - Conditions applicable to provision of CMRS service by incumbent Local Exchange Carriers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... terms and conditions of the transaction on the Internet within 10 days of the transaction through the... Radio Service (Broadband CMRS). For the purposes of this section, “broadband CMRS” means Cellular Radiotelephone Service (part 22, subpart H of this chapter), Specialized Mobile Radio (part 90, subpart S of this...

47 CFR 20.20 - Conditions applicable to provision of CMRS service by incumbent Local Exchange Carriers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... terms and conditions of the transaction on the Internet within 10 days of the transaction through the... Radio Service (Broadband CMRS). For the purposes of this section, “broadband CMRS” means Cellular Radiotelephone Service (part 22, subpart H of this chapter), Specialized Mobile Radio (part 90, subpart S of this...

Colleges Angle for Billions to Build Obama's Broadband Network

ERIC Educational Resources Information Center

Parry, Marc

2009-01-01

As the federal government prepares to pour billions of stimulus dollars into increased broadband Internet access, colleges are trying to claim much of the money and shape the emerging national networking policy. Their focus is $4.7-billion that will be doled out under a new grant program administered by a small Commerce Department agency called…

78 FR 6216 - Extension of the Commission's Rules Regarding Outage Reporting to Interconnected Voice Over...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-30

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 4 [PS Docket No. 11-82; DA 12-1962] Extension of the Commission's Rules Regarding Outage Reporting to Interconnected Voice Over Internet Protocol Service Providers and Broadband Internet Service Providers AGENCY: Federal Communications Commission. ACTION: Final...

Special Report: High-Speed Data Races Home.

ERIC Educational Resources Information Center

Clark, David D.

1999-01-01

Describes the worldwide use of Internet services and the changing technology to fill consumer requirements. Explains the technology that is used to provide Internet access. Focuses on the cable TV, telephone, and satellite-based communications industries. Sees satellites, which are mostly geosynchronous, as a broadband option, which is risky from…

CALEA: Prepare for the Worst, Hope for the Best

ERIC Educational Resources Information Center

Wigen, Wendy

2006-01-01

On August 5, 2005, nearly a year since requesting public comment on the issue, the Federal Communications Commission (FCC) voted to extend the Communications Assistance for Law Enforcement Act (CALEA) to broadband Internet and interconnected Voice-over-Internet Protocol (VoIP) providers. This includes college and university campus networks, as…

Sources, properties, and energization of auroral particle precipitation

NASA Astrophysics Data System (ADS)

Wing, S.; Johnson, J.; Khazanov, G. V.

2017-12-01

The sources of and the physical processes associated with the auroral ion and electron precipitation are studied with DMSP satellites. The electron aurora has been previously classified into three categories: diffuse, monoenergetic, and broadband aurorae. The diffuse auroral electrons can be observed mainly in 22:00 - 09:00 MLT, which coincides much with the spatial distribution of the whistler-mode chorus waves that have been shown to be the predominant mechanism for pitch-angle scattering magnetospheric electrons into the loss cone, but there appears to be a separate population near noon, which may be associated with solar wind particles. The broadband auroral electrons can be found mostly at 22:00 - 02:00 MLT and pre-noon where Alfvén waves, which cause broadband electron acceleration, are observed in the magnetosphere. On the other hand, the monoenergetic auroral electrons can be observed at dusk-midnight sector, pre- and post-noon. The monoenergetic electrons have been previously thought as magnetospheric electrons that have gone through a quasi-static parallel electric field in the upward field-aligned current regions. However, there may be a connection between monoenergetic and broadband electrons in that the low frequency Alfvén wave-electron interaction can result in monoenergetic electron signature. This is consistent with the observations where broadband and monoenergetic electrons are often spatially co-located. Precipitating electrons can ionize the neutrals in the ionosphere, which can travel upward, which can precipitate in the opposite hemisphere or reflected back to the same hemisphere by upward field-aligned potential drop. Either way, the upward flowing electrons can greatly modify the initial precipitating electron population. Substorm processes increase the power of the diffuse, monoenergetic, and broadband electron aurora by 310%, 71%, and 170%, respectively. Substorms energize the ion aurora mainly in the 21:00-05:00 MLT sector. The duration of the substorm cycle for monoenergetic and broadband auroral is 5 hr, but it is larger than 5 hr for diffuse auroral electrons.

Free space optical wireless (FSOW) for broadband access

NASA Astrophysics Data System (ADS)

Khan, David A.

2002-05-01

The dramatic growth of the Internet and the optical core network that supports it has recently slowed down in spite of a growing appetite for bandwidth-hungry services and applications, particularly those with video content. One of the major reasons for the pause is the lack of affordable broadband access transport facilities extending optical rate connectivity over the last mile.

From District to Desktop: Making the Most of Broadband in Florida Schools. A White Paper

ERIC Educational Resources Information Center

Everhart, Nancy; Mardis, Marcia; Johnston, Melissa; Smith, Daniella

2009-01-01

For Americans to engage in a global information society, it is critical that they have access to high-speed, high-bandwidth Internet, meaning broadband. Network connectivity opens up a wealth of possibilities to K-12 educators. While it has the potential to result in fundamental changes in teaching methods, it can definitely be used to enhance…

The 2005 Minnesota Internet Study: An Examination of Metro/Rural Differences in Digital Technology Adoption

ERIC Educational Resources Information Center

Center for Rural Policy and Development, 2006

2006-01-01

Since 2001 the Center for Rural Policy & Development (CRPD) has annually conducted surveys of rural Minnesota households to discern the level of computer ownership, Internet connectivity and broadband adoption throughout rural Minnesota. Since the beginning of this longitudinal effort, significant increases in technology adoption have been…

Real-time Internet connections: implications for surgical decision making in laparoscopy.

PubMed

Broderick, T J; Harnett, B M; Doarn, C R; Rodas, E B; Merrell, R C

2001-08-01

To determine whether a low-bandwidth Internet connection can provide adequate image quality to support remote real-time surgical consultation. Telemedicine has been used to support care at a distance through the use of expensive equipment and broadband communication links. In the past, the operating room has been an isolated environment that has been relatively inaccessible for real-time consultation. Recent technological advances have permitted videoconferencing over low-bandwidth, inexpensive Internet connections. If these connections are shown to provide adequate video quality for surgical applications, low-bandwidth telemedicine will open the operating room environment to remote real-time surgical consultation. Surgeons performing a laparoscopic cholecystectomy in Ecuador or the Dominican Republic shared real-time laparoscopic images with a panel of surgeons at the parent university through a dial-up Internet account. The connection permitted video and audio teleconferencing to support real-time consultation as well as the transmission of real-time images and store-and-forward images for observation by the consultant panel. A total of six live consultations were analyzed. In addition, paired local and remote images were "grabbed" from the video feed during these laparoscopic cholecystectomies. Nine of these paired images were then placed into a Web-based tool designed to evaluate the effect of transmission on image quality. The authors showed for the first time the ability to identify critical anatomic structures in laparoscopy over a low-bandwidth connection via the Internet. The consultant panel of surgeons correctly remotely identified biliary and arterial anatomy during six laparoscopic cholecystectomies. Within the Web-based questionnaire, 15 surgeons could not blindly distinguish the quality of local and remote laparoscopic images. Low-bandwidth, Internet-based telemedicine is inexpensive, effective, and almost ubiquitous. Use of these inexpensive, portable technologies will allow sharing of surgical procedures and decisions regardless of location. Internet telemedicine consistently supported real-time intraoperative consultation in laparoscopic surgery. The implications are broad with respect to quality improvement and diffusion of knowledge as well as for basic consultation.

Old Buildings Broadband Home Networks: Technologies and Services Overview

NASA Astrophysics Data System (ADS)

Fantacci, Romano; Pecorella, Tommaso; Micciullo, Luigia; Viti, Roberto; Pasquini, Vincenzo; Calì, Marco

2014-05-01

Internet broadband access is becoming a reality in many countries. To fully exploit the benefits from high-speed connection, both suitable home network connectivity and advanced services support have to be made available to the user. In this article, issues relative to the upgrade of existing home networks, particularly in old buildings, together with networking and security requirements are addressed, and possible solutions are proposed.

Cyber Astronomy: A Cyber University Course for School Students

ERIC Educational Resources Information Center

Chan, C. W.; Wong, K. Y. Michael

2003-01-01

Teaching university physics through the internet is not new, but a new course providing the same service for secondary school students is the first of its kind in Hong Kong. Taking advantage of the fast and affordable broadband internet in the region, some university courses have been converted to a cyber curriculum suitable for secondary school…

Remote Spectroscopy in the Visible Using Fibers on the Optical Internet Network

ERIC Educational Resources Information Center

Ribeiro, Rafael A. S.; de Oliveira, Anderson R.; Zilio, Sergio C.

2010-01-01

The work presented here demonstrates the feasibility of using the single-mode fibers of an optical Internet network to deliver visible light between separate laboratories as a way to perform remote spectroscopy in the visible for teaching purposes. The coupling of a broadband light source into the single-mode fiber (SMF) and the characterization…

Diffusion by one wave and by many waves

NASA Astrophysics Data System (ADS)

Albert, J. M.

2010-03-01

Radiation belt electrons and chorus waves are an outstanding instance of the important role cyclotron resonant wave-particle interactions play in the magnetosphere. Chorus waves are particularly complex, often occurring with large amplitude, narrowband but drifting frequency and fine structure. Nevertheless, modeling their effect on radiation belt electrons with bounce-averaged broadband quasi-linear theory seems to yield reasonable results. It is known that coherent interactions with monochromatic waves can cause particle diffusion, as well as radically different phase bunching and phase trapping behavior. Here the two formulations of diffusion, while conceptually different, are shown to give identical diffusion coefficients, in the narrowband limit of quasi-linear theory. It is further shown that suitably averaging the monochromatic diffusion coefficients over frequency and wave normal angle parameters reproduces the full broadband quasi-linear results. This may account for the rather surprising success of quasi-linear theory in modeling radiation belt electrons undergoing diffusion by chorus waves.

Diffusing light probing of aged wet foams

NASA Astrophysics Data System (ADS)

Slavnetskov, I. O.; Kalacheva, A. V.; Yuvchenko, S. A.; Markova, N. S.; Zimnyakov, D. A.

2018-04-01

Features of diffusing light probes of aged liquid foams are discussed. These probes were carried out using broadband and laser radiation with the wavelength of 532 nm. Experimental data were obtained for aged samples of Gillette shaving cream as a model foamed substance. The coefficients of diffusion and collimated transmittance were applied for characterization of the structural changes in the aged wet foams. Also, the changes in the liquid fraction due to gravitational drainage were monitored using volumometric measurements in the course of the foam aging. Obtained empirical data on the diffuse and collimated transmittance were used as the reference values for correction of the spectral measurements in the visible range with a broadband source of probe light. The problem of correction of the collimated transmittance partially corrupted by the diffusing component of multiply scattered light is discussed.

POTS to broadband ... cable modems.

PubMed

Kabachinski, Jeff

2003-01-01

There have been 3 columns talking about broadband communications and now at the very end when it's time to compare using a telco or cableco, I'm asking does it really matter? So what if I can actually get the whole 30 Mbps with a cable network when the website I'm connecting to is running on an ISDN line at 128 Kbps? Broadband offers a lot more bandwidth than the connections many Internet servers have today. Except for the biggest websites, many servers connect to the Internet with a switched 56-Kbps, ISDN, or fractional T1 line. Even with the big websites, my home network only runs a 10 Mbps Ethernet connection to my cable modem. Maybe it doesn't matter that the cable lines are shared or that I can only get 8 Mbps from an ADSL line. Maybe the ISP that I use has a T1 line connection to the Internet so my new ADSL modem has a fatter pipe than my provider! (See table 1). It all makes me wonder what's in store for us in the future. PC technology has increased exponentially in the last 10 years with super fast processor speeds, hard disks of hundreds of gigabytes, and amazing video and audio. Internet connection speeds have failed to keep the same pace. Instead of hundreds of times better or faster--modem speeds are barely 10 times faster. Broadband connections offer some additional speed but still not comparable growth as broadband connections are still in their infancy. Rather than trying to make use of existing communication paths, maybe we need a massive infrastructure makeover of something new. How about national wireless access points so we can connect anywhere, anytime? To use the latest and fastest wireless technology you will simply need to buy another $9.95 WLAN card or download the latest super slick WLAN compression/encryption software. Perhaps it is time for a massive infra-restructuring. Consider the past massive infrastructure efforts. The telcos needed to put in their wiring infrastructure starting in the 1870s before telephones were useful to the masses. CATV was a minor player in the TV broadcast business before they installed their cabling infrastructure and went national. Even automobiles were fairly useless until roads were paved and the highway infrastructure was built!

Intrusion detection and monitoring for wireless networks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, Eric D.; Van Randwyk, Jamie A.; Lee, Erik J.

Wireless computer networks are increasing exponentially around the world. They are being implemented in both the unlicensed radio frequency (RF) spectrum (IEEE 802.11a/b/g) and the licensed spectrum (e.g., Firetide [1] and Motorola Canopy [2]). Wireless networks operating in the unlicensed spectrum are by far the most popular wireless computer networks in existence. The open (i.e., proprietary) nature of the IEEE 802.11 protocols and the availability of ''free'' RF spectrum have encouraged many producers of enterprise and common off-the-shelf (COTS) computer networking equipment to jump into the wireless arena. Competition between these companies has driven down the price of 802.11 wirelessmore » networking equipment and has improved user experiences with such equipment. The end result has been an increased adoption of the equipment by businesses and consumers, the establishment of the Wi-Fi Alliance [3], and widespread use of the Alliance's ''Wi-Fi'' moniker to describe these networks. Consumers use 802.11 equipment at home to reduce the burden of running wires in existing construction, facilitate the sharing of broadband Internet services with roommates or neighbors, and increase their range of ''connectedness''. Private businesses and government entities (at all levels) are deploying wireless networks to reduce wiring costs, increase employee mobility, enable non-employees to access the Internet, and create an added revenue stream to their existing business models (coffee houses, airports, hotels, etc.). Municipalities (Philadelphia; San Francisco; Grand Haven, MI) are deploying wireless networks so they can bring broadband Internet access to places lacking such access; offer limited-speed broadband access to impoverished communities; offer broadband in places, such as marinas and state parks, that are passed over by traditional broadband providers; and provide themselves with higher quality, more complete network coverage for use by emergency responders and other municipal agencies. In short, these Wi-Fi networks are being deployed everywhere. Much thought has been and is being put into evaluating cost-benefit analyses of wired vs. wireless networks and issues such as how to effectively cover an office building or municipality, how to efficiently manage a large network of wireless access points (APs), and how to save money by replacing an Internet service provider (ISP) with 802.11 technology. In comparison, very little thought and money are being focused on wireless security and monitoring for security purposes.« less

Bayesian approach to non-Gaussian field statistics for diffusive broadband terahertz pulses.

PubMed

Pearce, Jeremy; Jian, Zhongping; Mittleman, Daniel M

2005-11-01

We develop a closed-form expression for the probability distribution function for the field components of a diffusive broadband wave propagating through a random medium. We consider each spectral component to provide an individual observation of a random variable, the configurationally averaged spectral intensity. Since the intensity determines the variance of the field distribution at each frequency, this random variable serves as the Bayesian prior that determines the form of the non-Gaussian field statistics. This model agrees well with experimental results.

Internet Television News in the Classroom TF1: Improved Features Make Sites More Useful

ERIC Educational Resources Information Center

LeLoup, Jean W.; Ponterio, Robert

2004-01-01

Truly current, up-to-the-minute video by native speakers using the language for real communication can make the language and culture come alive for students. With the explosion of broadband Internet access through cable and DSL, better connections in schools, faster low cost computers, and better graphics adapters, access to authentic video on the…

Parents - Reboot.FCC.gov

Science.gov Websites

Reboot Events Calendar Open Meetings Workshops Reboot Live Video Archives Initiatives Reform Systems Calendar Open Meetings Workshops Reboot Live Video Archives Initiatives Broadband.gov OpenInternet.gov

Modulation and multiplexing in ultra-broadband photonic internet: Part II

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-06-01

In this paper, there is presented a review of our today's understanding of the ultimately broadband photonic Internet. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM.

Ultra-broadband photonic internet

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-06-01

In this paper, there is presented a review of our today's understanding of the ultimately broadband photonic Internet. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM.

Modulation and multiplexing in ultra-broadband photonic internet: Part I

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-06-01

In this paper, there is presented a review of our today's understanding of the ultimately broadband photonic Internet. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM.

Design and validation of a diffuse reflectance and spectroscopic microendoscope with poly(dimethylsioxane)-based phantoms

PubMed Central

Greening, Gage J.; Powless, Amy J.; Hutcheson, Joshua A.; Prieto, Sandra P.; Majid, Aneeka A.; Muldoon, Timothy J.

2015-01-01

Many cases of epithelial cancer originate in basal layers of tissue and are initially undetected by conventional microendoscopy techniques. We present a bench-top, fiber-bundle microendoscope capable of providing high resolution images of surface cell morphology. Additionally, the microendoscope has the capability to interrogate deeper into material by using diffuse reflectance and broadband diffuse reflectance spectroscopy. The purpose of this multimodal technique was to overcome the limitation of microendoscopy techniques that are limited to only visualizing morphology at the tissue or cellular level. Using a custom fiber optic probe, high resolution surface images were acquired using topical proflavine to fluorescently stain non-keratinized epithelia. A 635 nm laser coupled to a 200 μm multimode fiber delivers light to the sample and the diffuse reflectance signal was captured by a 1 mm image guide fiber. Finally, a tungsten-halogen lamp coupled to a 200 μm multimode fiber delivers broadband light to the sample to acquire spectra at source-detector separations of 374, 729, and 1051 μm. To test the instrumentation, a high resolution proflavine-induced fluorescent image of resected healthy mouse colon was acquired. Additionally, five monolayer poly(dimethylsiloxane)-based optical phantoms with varying absorption and scattering properties were created to acquire diffuse reflectance profiles and broadband spectra. PMID:25983372

Design and validation of a diffuse reflectance and spectroscopic microendoscope with poly(dimethylsiloxane)-based phantoms

NASA Astrophysics Data System (ADS)

Greening, Gage J.; Powless, Amy J.; Hutcheson, Joshua A.; Prieto, Sandra P.; Majid, Aneeka A.; Muldoon, Timothy J.

2015-03-01

Many cases of epithelial cancer originate in basal layers of tissue and are initially undetected by conventional microendoscopy techniques. We present a bench-top, fiber-bundle microendoscope capable of providing high resolution images of surface cell morphology. Additionally, the microendoscope has the capability to interrogate deeper into material by using diffuse reflectance and broadband diffuse reflectance spectroscopy. The purpose of this multimodal technique was to overcome the limitation of microendoscopy techniques that are limited to only visualizing morphology at the tissue or cellular level. Using a custom fiber optic probe, high resolution surface images were acquired using topical proflavine to fluorescently stain non-keratinized epithelia. A 635 nm laser coupled to a 200 μm multimode fiber delivers light to the sample and the diffuse reflectance signal was captured by a 1 mm image guide fiber. Finally, a tungsten-halogen lamp coupled to a 200 μm multimode fiber delivers broadband light to the sample to acquire spectra at source-detector separations of 374, 729, and 1051 μm. To test the instrumentation, a high resolution proflavine-induced fluorescent image of resected healthy mouse colon was acquired. Additionally, five monolayer poly(dimethylsiloxane)-based optical phantoms with varying absorption and scattering properties were created to acquire diffuse reflectance profiles and broadband spectra.

Broadband Affordability Act of 2009

THOMAS, 111th Congress

Rep. Matsui, Doris O. [D-CA-5

2009-09-24

House - 09/25/2009 Referred to the Subcommittee on Communications, Technology, and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Rural Broadband Initiative Act of 2010

THOMAS, 111th Congress

Rep. Murphy, Scott [D-NY-20

2010-01-27

House - 01/29/2010 Referred to the Subcommittee on Communications, Technology, and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

The first 100 feet: New options for Internet and broadband access. Final report, June 1, 1996--January 31, 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

Branscomb, L.; Hurley, D.; Keller, J.

1998-04-01

This project was undertaken to explore new options for connecting homes and small businesses to high-speed communications networks, such as the Internet. Fundamental to this inquiry was an interest in looking at options which are newly enabled through changes in technology and regulation, and which go beyond the traditional topdown, centralized model for local access. In particular, the authors focused on opportunities for end-user and community-level investment. This project was intended to investigate the opportunities presented by the decreasing cost of computing and networking platforms, the unbundling of local exchange network elements, and the intelligent endpoints model of networking bestmore » exemplified by the Internet. Do these factors, along with communications technologies such as spread spectrum wireless, digital subscriber line services, and the ability to modulate a communications signal over the electric power line infrastructure, enable new models for end-user investment in intelligent infrastructure as a leverage point for accessing the broadband network? This question was first explored through a two-day conference held at the Freedom Forum in Arlington, Virginia, October 29 and 30, 1996. The workshop addressed issues in the consumer adoption of new communications technologies, use of the electric power line infrastructure, the role of municipalities, and the use of alternative technologies, such as XDSL, satellite, spread spectrum wireless, LMDS, and others. The best of these papers have been further developed, with editorial guidance provided by Harvard, and compiled in the form of a book (The First 100 Feet: New Options for Internet and Broadband Access, Deborah Hurley and James Keller, eds., MIT Press, 1998) to be published as part of the MIT Press Spring 1998 catalogue. A summary of topics covered by the book is given in this report.« less

Forming a Cyber Coalition

DTIC Science & Technology

2012-04-06

Estonia 6 :  98% of Estonian‟s territory was covered with Internet access: fixed line, broadband, WiMax, WiFi , and CDMA21 mobile wireless Internet...The hacked homepage displayed a prominent image of Bashar al-Assad, the President of Syria, with a text proclaiming “Syrian Electronic Army Were...update and harmonize their criminal laws against hacking , infringements on copyrights, computer facilitated fraud, child pornography, and other illicit

Advanced Broadband Infrastructure Bond Initiative of 2009

THOMAS, 111th Congress

Rep. Eshoo, Anna G. [D-CA-14

2009-01-28

House - 02/02/2009 Referred to the Subcommittee on Communications, Technology, and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Triple Play over Satellite, Ka-Band Making the Difference

NASA Astrophysics Data System (ADS)

Benoit, Guillaume; Fenech, Hector; Pezzana, Stefano

Over the last years a number of operators have been deploying satellite-based consumer internet access services to reduce the digital divide and capture the market of households not covered by ADSL, cable or wireless broadband. These operators are proposing a step change improvement in the economics of consumer service, with lower terminal costs, broadband access with monthly fees comparable to ADSL and an integrated technology simplifying the process of terminal installation, provisioning and management.

Analysis and Simulation of Traffic Control for Resource Management in DVB-Based Broadband Satellite Access Networks

NASA Astrophysics Data System (ADS)

Impemba, Ernesto; Inzerilli, Tiziano

2003-07-01

Integration of satellite access networks with the Internet is seen as a strategic goal to achieve in order to provide ubiquitous broadband access to Internet services in Next Generation Networks (NGNs). One of the main interworking aspects which has been most studied is an efficient management of satellite resources, i.e. bandwidth and buffer space, in order to satisfy most demanding application requirements as to delay control and bandwidth assurance. In this context, resource management in DVB-S/DVB-RCS satellite technologies, emerging technologies for broadband satellite access and transport of IP applications, is a research issue largely investigated as a means to provide efficient bi-directional communications across satellites. This is in particular one of the principal goals of the SATIP6 project, sponsored within the 5th EU Research Programme Framework, i.e. IST. In this paper we present a possible approach to efficiently exploit bandwidth, the most critical resource in a broadband satellite access network, while pursuing satisfaction of delay and bandwidth requirements for applications with guaranteed QoS through a traffic control architecture to be implemented in ground terminals. Performance of this approach is assessed in terms of efficient exploitation of the uplink bandwidth and differentiation and minimization of queuing delays for most demanding applications over a time-varying capacity. Opnet simulations is used as analysis tool.

Real-Time Internet Connections: Implications for Surgical Decision Making in Laparoscopy

PubMed Central

Broderick, Timothy J.; Harnett, Brett M.; Doarn, Charles R.; Rodas, Edgar B.; Merrell, Ronald C.

2001-01-01

Objective To determine whether a low-bandwidth Internet connection can provide adequate image quality to support remote real-time surgical consultation. Summary Background Data Telemedicine has been used to support care at a distance through the use of expensive equipment and broadband communication links. In the past, the operating room has been an isolated environment that has been relatively inaccessible for real-time consultation. Recent technological advances have permitted videoconferencing over low-bandwidth, inexpensive Internet connections. If these connections are shown to provide adequate video quality for surgical applications, low-bandwidth telemedicine will open the operating room environment to remote real-time surgical consultation. Methods Surgeons performing a laparoscopic cholecystectomy in Ecuador or the Dominican Republic shared real-time laparoscopic images with a panel of surgeons at the parent university through a dial-up Internet account. The connection permitted video and audio teleconferencing to support real-time consultation as well as the transmission of real-time images and store-and-forward images for observation by the consultant panel. A total of six live consultations were analyzed. In addition, paired local and remote images were “grabbed” from the video feed during these laparoscopic cholecystectomies. Nine of these paired images were then placed into a Web-based tool designed to evaluate the effect of transmission on image quality. Results The authors showed for the first time the ability to identify critical anatomic structures in laparoscopy over a low-bandwidth connection via the Internet. The consultant panel of surgeons correctly remotely identified biliary and arterial anatomy during six laparoscopic cholecystectomies. Within the Web-based questionnaire, 15 surgeons could not blindly distinguish the quality of local and remote laparoscopic images. Conclusions Low-bandwidth, Internet-based telemedicine is inexpensive, effective, and almost ubiquitous. Use of these inexpensive, portable technologies will allow sharing of surgical procedures and decisions regardless of location. Internet telemedicine consistently supported real-time intraoperative consultation in laparoscopic surgery. The implications are broad with respect to quality improvement and diffusion of knowledge as well as for basic consultation. PMID:11505061

Random Combinatorial Gradient Metasurface for Broadband, Wide-Angle and Polarization-Independent Diffusion Scattering.

PubMed

Zhuang, Yaqiang; Wang, Guangming; Liang, Jiangang; Cai, Tong; Tang, Xiao-Lan; Guo, Tongfeng; Zhang, Qingfeng

2017-11-29

This paper proposes an easy, efficient strategy for designing broadband, wide-angle and polarization-independent diffusion metasurface for radar cross section (RCS) reduction. A dual-resonance unit cell, composed of a cross wire and cross loop (CWCL), is employed to enhance the phase bandwidth covering the 2π range. Both oblique-gradient and horizontal-gradient phase supercells are designed for illustration. The numerical results agree well with the theoretical ones. To significantly reduce backward scattering, the random combinatorial gradient metasurface (RCGM) is subsequently constructed by collecting eight supercells with randomly distributed gradient directions. The proposed metasurface features an enhanced specular RCS reduction performance and less design complexity compared to other candidates. Both simulated and measured results show that the proposed RCGM can significantly suppress RCS and exhibits broadband, wide-angle and polarization independence features.

7 CFR 1739.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... building with at least ten (10) Computer Access Points, that is used for the purposes of providing free access to and/or instruction in the use of broadband Internet service, and is of the appropriate size to...

7 CFR 1739.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... building with at least ten (10) Computer Access Points, that is used for the purposes of providing free access to and/or instruction in the use of broadband Internet service, and is of the appropriate size to...

Internet Freedom, Broadband Promotion, and Consumer Protection Act of 2011

THOMAS, 112th Congress

Sen. Cantwell, Maria [D-WA

2011-01-25

Senate - 01/25/2011 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

47 CFR 8.7 - No unreasonable discrimination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false No unreasonable discrimination. 8.7 Section 8.7... discrimination. A person engaged in the provision of fixed broadband Internet access service, insofar as such... unreasonable discrimination. ...

Spectral shifts as a signature of the onset of diffusion of broadband terahertz pulses.

PubMed

Pearce, Jeremy; Jian, Zhongping; Mittleman, Daniel M

2004-12-15

We describe measurements of polarization dynamics as a probe of multiple scattering of photons in a random medium by use of single-cycle terahertz pulses. We measure the degree of polarization and correlate it directly with the single-scattering regime in the time domain. We also measure the evolution of the temporal phase of the radiation and show that the average spectral content depends on the state of polarization. In the case of broadband radiation, this effect can be used to distinguish photons that have been scattered a few times from those that are propagating diffusively.

Optoenergy storage and random walks assisted broadband amplification in Er3+-doped (Pb,La)(Zr,Ti)O3 disordered ceramics.

PubMed

Xu, Long; Zhao, Hua; Xu, Caixia; Zhang, Siqi; Zou, Yingyin K; Zhang, Jingwen

2014-02-01

A broadband optical amplification was observed and investigated in Er3+-doped electrostrictive ceramics of lanthanum-modified lead zirconate titanate under a corona atmosphere. The ceramic structure change caused by UV light, electric field, and random walks originated from the diffusive process in intrinsically disordered materials may all contribute to the optical amplification and the associated energy storage. Discussion based on optical energy storage and diffusive equations was given to explain the findings. Those experiments performed made it possible to study random walks and optical amplification in transparent ceramics materials.

Superficial view of fiber to the home (FTTH)

NASA Astrophysics Data System (ADS)

Li, Xiaolin

2004-04-01

For the past few years, telecom companies have been working diligently to provide us with pseudo-broadband Internet connections over copper (DSL) and cable (cable modem). I use the term "pseudo-broadband" because the existing telecom infrastructure can only provide speeds of up to 1.5 megabits per second. (In theory, cable modem can provide up to 2.5 megabits per second, but in reality nobody obtains these speeds because the shared aspects of cable modem results in lower speeds.) No doubt improvements will be made over the next few years to squeeze more out of copper and cable, but it doesn't matter, because fiber to the home is coming, and it will be here faster than most people predict. In case you're wondering, FTTH provides download speeds of up to 155 megabits per second -- that's 100 times faster than the pseudo-broadband DSL and cable modem connections. Can you say instantaneous data transfer? Can you say, video on demand? SBC and Bellsouth are two of the telecom giants pioneering FTTH. The initial markets are new residential construction, because you don't have to dig up streets in an existing neighborhood to lay the fiber optic cable. SBC plans to wire 6,000 homes in a community in San Francisco by late next year. Initial net connections will only be about 5 MB/second -- far from the theoretical maximum of 155 MB/second, but still blazingly fast compared to DSL and cable modem. BellSouth is also pioneering FTTH with a trial project involving more than 400 people in the Atlanta suburb of Dunwoody. These individuals have Internet connections of about 10 MB/second! No doubt there will be stumbles along the way to providing FTTH. No doubt there are challenges to making FTTH cost effective. No doubt it will take years before most residences in the world have true broadband Internet access.

The Rural Wings Project: Bridging the Digital Divide with Satellite-Provided Internet. Phase I--Identifying and Analysing the Learning Needs of 31 Communities in 10 Countries

ERIC Educational Resources Information Center

Hansson, Henrik; Mihailidis, Paul; Larsson, Ken; Sotiriou, Menelaos; Sotiriou, Sofoklis; Uzunoglu, Nikolaos; Gargalakos, Michail

2007-01-01

The digitally marginalised communities are in focus in the EU-funded Rural Wings project 2006-2008. The aim is to identify and analyse the user learning needs in non-connected communities and to meet these needs by providing satellite Internet broadband connections, education and tools. This article reports the findings of the user needs…

Transition plan.

DOT National Transportation Integrated Search

2009-02-02

Although the 9-1-1 system has been a success for nearly 40 years, changes in the publics use of : technology, the saturation of the mobile market, and the spread of Voice over Internet Protocol (VoIP) : telephony over broadband are contributing to...

Rural New Zealand health professionals' perceived barriers to greater use of the internet for learning.

PubMed

Janes, Ron; Arroll, Bruce; Buetow, Stephen; Coster, Gregor; McCormick, Ross; Hague, Iain

2005-01-01

The purpose of this research was to investigate rural North Island (New Zealand) health professionals' attitudes and perceived barriers to using the internet for ongoing professional learning. A cross-sectional postal survey of all rural North Island GPs, practice nurses and pharmacists was conducted in mid-2003. The questionnaire contained both quantitative and qualitative questions. The transcripts from two open questions requiring written answers were analysed for emergent themes, which are reported here. The first open question asked: 'Do you have any comments on the questionnaire, learning, computers or the Internet?' The second open question asked those who had taken a distance-learning course using the internet to list positive and negative aspects of their course, and suggest improvements. Out of 735 rural North Island health professionals surveyed, 430 returned useable questionnaires (a response rate of 59%). Of these, 137 answered the question asking for comments on learning, computers and the internet. Twenty-eight individuals who had completed a distance-learning course using the internet, provided written responses to the second question. Multiple barriers to greater use of the internet were identified. They included lack of access to computers, poor availability of broadband (fast) internet access, lack of IT skills/knowledge, lack of time, concerns about IT costs and database security, difficulty finding quality information, lack of time, energy or motivation to learn new skills, competing priorities (eg family), and a preference for learning modalities which include more social interaction. Individuals also stated that rural health professionals needed to engage the technology, because it provided rapid, flexible access from home or work to a significant health information resource, and would save money and travelling time to urban-based education. In mid-2003, there were multiple barriers to rural North Island health professionals making greater use of the internet for learning. Now that access to broadband internet is available in all rural towns in New Zealand, there is a clear need to address the other identified barriers, especially the self-reported lack of IT skills, which are preventing many in the rural health workforce from gaining maximum advantage from both computers and the internet.

Investigation of the validity of quasilinear theory for electron Landau damping in a tokamak using a broad-band wave effect

DOE PAGES

Lee, Jungpyo; Bonoli, Paul; Wright, John

2011-01-01

The quasilinear diffusion coefficient assuming a constant magnetic field along the electron orbit is widely used to describe electron Landau damping of waves in a tokamak where the magnitude of the magnetic field varies on a flux surface. To understand the impact of violating the constant magnetic field assumption, we introduce the effect of a broad-bandwidth wave spectrum which has been used in the past to validate quasilinear theory for the fast decorrelation process between resonances. By the reevaluation of the diffusion coefficient through the level of the phase integral for the tokamak geometry with the broad-band wave effect included,more » we identify the three acceptable errors for the use of the quasilinear diffusion coefficient.« less

The Digital Divide: A Global View

NASA Astrophysics Data System (ADS)

Ntoko, Alexander

2011-04-01

Huge progress was made in bridging the digital divide in first decade of 21^st century. This was largely due to the explosive growth of mobile, which saw numbers rise from under 500 million to over five billion mobile cellular subscriptions in just ten years. With household mobile penetration rates of over 50% even in rural areas of developing countries, we have achieved the dream of bringing all the world's people within reach of communications technology. We must now, however, replicate the mobile miracle for the Internet, and especially broadband, if we are to avoid creating a new broadband breach to replace the digital divide. Three things need to happen for this to be achieved: firstly, broadband needs to be brought to the top of the development agenda; secondly, broadband needs to become much more affordable and thirdly, security needs to be part of the strategy.

Using selection bias to explain the observed structure of Internet diffusions

PubMed Central

Golub, Benjamin; Jackson, Matthew O.

2010-01-01

Recently, large datasets stored on the Internet have enabled the analysis of processes, such as large-scale diffusions of information, at new levels of detail. In a recent study, Liben-Nowell and Kleinberg [(2008) Proc Natl Acad Sci USA 105:4633–4638] observed that the flow of information on the Internet exhibits surprising patterns whereby a chain letter reaches its typical recipient through long paths of hundreds of intermediaries. We show that a basic Galton–Watson epidemic model combined with the selection bias of observing only large diffusions suffices to explain these patterns. Thus, selection biases of which data we observe can radically change the estimation of classical diffusion processes. PMID:20534439

The Massive Stellar Population in the Diffuse Ionized Gas of M33

NASA Technical Reports Server (NTRS)

Hoopes, Charles G.; Walterbos, Rene A. M.

1995-01-01

We compare Far-UV, H alpha, and optical broadband images of the nearby spiral galaxy M33, to investigate the massive stars associated with the diffuse ionized gas. The H-alpha/FUV ratio is higher in HII regions than in the DIG, possibly indicating that an older population ionizes the DIG. The broad-band colors support this conclusion. The HII region population is consistent with a young burst, while the DIG colors resemble an older population with constant star formation. Our results indicate that there may be enough massive field stars to ionize the DIG, without the need for photon leakage from HII regions.

Broadband diffuse terahertz wave scattering by flexible metasurface with randomized phase distribution

PubMed Central

Zhang, Yin; Liang, Lanju; Yang, Jing; Feng, Yijun; Zhu, Bo; Zhao, Junming; Jiang, Tian; Jin, Biaobing; Liu, Weiwei

2016-01-01

Suppressing specular electromagnetic wave reflection or backward radar cross section is important and of broad interests in practical electromagnetic engineering. Here, we present a scheme to achieve broadband backward scattering reduction through diffuse terahertz wave reflection by a flexible metasurface. The diffuse scattering of terahertz wave is caused by the randomized reflection phase distribution on the metasurface, which consists of meta-particles of differently sized metallic patches arranged on top of a grounded polyimide substrate simply through a certain computer generated pseudorandom sequence. Both numerical simulations and experimental results demonstrate the ultralow specular reflection over a broad frequency band and wide angle of incidence due to the re-distribution of the incident energy into various directions. The diffuse scattering property is also polarization insensitive and can be well preserved when the flexible metasurface is conformably wrapped on a curved reflective object. The proposed design opens up a new route for specular reflection suppression, and may be applicable in stealth and other technology in the terahertz spectrum. PMID:27225031

Broadband diffuse terahertz wave scattering by flexible metasurface with randomized phase distribution.

PubMed

Zhang, Yin; Liang, Lanju; Yang, Jing; Feng, Yijun; Zhu, Bo; Zhao, Junming; Jiang, Tian; Jin, Biaobing; Liu, Weiwei

2016-05-26

Suppressing specular electromagnetic wave reflection or backward radar cross section is important and of broad interests in practical electromagnetic engineering. Here, we present a scheme to achieve broadband backward scattering reduction through diffuse terahertz wave reflection by a flexible metasurface. The diffuse scattering of terahertz wave is caused by the randomized reflection phase distribution on the metasurface, which consists of meta-particles of differently sized metallic patches arranged on top of a grounded polyimide substrate simply through a certain computer generated pseudorandom sequence. Both numerical simulations and experimental results demonstrate the ultralow specular reflection over a broad frequency band and wide angle of incidence due to the re-distribution of the incident energy into various directions. The diffuse scattering property is also polarization insensitive and can be well preserved when the flexible metasurface is conformably wrapped on a curved reflective object. The proposed design opens up a new route for specular reflection suppression, and may be applicable in stealth and other technology in the terahertz spectrum.

Security for Telecommuting and Broadband Communications: Recommendations of the National Institute of Standards and Technology

DTIC Science & Technology

2002-08-01

Aware http://www.lavasoftusa.com/ Adware, Alexa 1.0-5.0, Aureate 1.0-3.0, Comet Cursor 1.0-2.0, Cydoor, Doubleclick, DSSAgent, EverAd, EzUla...Internet. Known as “voice over IP” (VOIP), the services convert speech to Internet messages and transmit them to a facility that interfaces with the...reporting, handling, prevention, and recognition . National Information Assurance Partnership (NIAP) - http://www.niap.nist.gov/ NIAP is a U.S

77 FR 37870 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

...: National Telecommunications and Information Administration (NTIA). Title: Computer and Internet Use Supplement to the Census Bureau's Current Population Survey (formerly Broadband Subscription and Usage Survey Supplement to the Census Bureau's Current Population Survey). OMB Control Number: 0660-0021. Form Number(s...

Policing the Information Highway.

ERIC Educational Resources Information Center

McClure, Ben

1996-01-01

Although broadband Asynchronous Transfer Mode (ATM) can deliver much greater amounts of information than narrow-band Integrated Services Digital Networks (ISDN), in reality bottlenecks place severe constraints on its performance. This article discusses shortfalls in Internet services, technology and user behavior, and describes efforts in the…

Design of broadband time-domain impedance boundary conditions using the oscillatory-diffusive representation of acoustical models.

PubMed

Monteghetti, Florian; Matignon, Denis; Piot, Estelle; Pascal, Lucas

2016-09-01

A methodology to design broadband time-domain impedance boundary conditions (TDIBCs) from the analysis of acoustical models is presented. The derived TDIBCs are recast exclusively as first-order differential equations, well-suited for high-order numerical simulations. Broadband approximations are yielded from an elementary linear least squares optimization that is, for most models, independent of the absorbing material geometry. This methodology relies on a mathematical technique referred to as the oscillatory-diffusive (or poles and cuts) representation, and is applied to a wide range of acoustical models, drawn from duct acoustics and outdoor sound propagation, which covers perforates, semi-infinite ground layers, as well as cavities filled with a porous medium. It is shown that each of these impedance models leads to a different TDIBC. Comparison with existing numerical models, such as multi-pole or extended Helmholtz resonator, provides insights into their suitability. Additionally, the broadly-applicable fractional polynomial impedance models are analyzed using fractional calculus.

Ultra-broadband and planar sound diffuser with high uniformity of reflected intensity

NASA Astrophysics Data System (ADS)

Fan, Xu-Dong; Zhu, Yi-Fan; Liang, Bin; Yang, Jing; Yang, Jun; Cheng, Jian-Chun

2017-09-01

Schroeder diffusers, as a classical design of acoustic diffusers proposed over 40 years ago, play key roles in many practical scenarios ranging from architectural acoustics to noise control to particle manipulation. Despite the great success of conventional acoustic diffusers, it is still worth pursuing ideal acoustic diffusers that are essentially expected to produce perfect sound diffuse reflection within the unlimited bandwidth. Here, we propose a different mechanism for designing acoustic diffusers to overcome the basic limits in intensity uniformity and working bandwidth in the previous designs and demonstrate a practical implementation by acoustic metamaterials with dispersionless phase-steering capability. In stark contrast to the existing production of diffuse fields relying on random scattering of sound energy by using a specific mathematical number sequence of periodically distributed unit cells, we directly mold the reflected wavefront into the desired shape by precisely manipulating the local phases of individual subwavelength metastructures. We also benchmark our design via numerical simulation with a commercially available Schroeder diffuser, and the results verify that our proposed diffuser scatters incident acoustic energy into all directions more uniformly within an ultra-broad band regardless of the incident angle. Furthermore, our design enables further improvement of the working bandwidth just by simply downscaling each individual element. With ultra-broadband functionality and high uniformity of reflected intensity, our metamaterial-based production of the diffusive field opens a route to the design and application of acoustic diffusers and may have a significant impact on various fields such as architectural acoustics and medical ultrasound imaging/treatment.

Multiple scattering of broadband terahertz pulses

NASA Astrophysics Data System (ADS)

Pearce, Jeremiah Glen

Propagation of single-cycle terahertz (THz) pulses through a random medium leads to dramatic amplitude and phase variations of the electric field because of multiple scattering. We present the first set of experiments that investigate the propagation of THz pulses through scattering media. The scattering of short pulses is a relevant subject to many communities in science and engineering, because the properties of multiply scattered or diffuse waves provide insights into the characteristics of the random medium. For example, the depolarization of diffuse waves has been used to form images of objects embedded in inhomogeneous media. Most of the previous scattering experiments have used narrowband optical radiation where measurements are limited to time averaged intensities or autocorrelation quantities, which contain no phase information of the pulses. In the experiments presented here, a terahertz time-domain spectrometer (THz-TDS) is used. A THz-TDS propagates single-cycle sub-picosecond pulses with bandwidths of over 1 THz into free space. The THz-TDS is a unique tool to study such phenomena, because it provides access to both the intensity and phase of those pulses through direct measurement of the temporal electric field. Because of the broad bandwidth and linear phase of the pulses, it is possible to simultaneously study Rayleigh scattering and the short wavelength limit in a single measurement. We study the diffusion of broadband single-cycle THz pulses by propagating the pulses through a highly scattering medium. Using the THz-TDS, time-domain measurements provide information on the statistics of both the amplitude and phase of the diffusive waves. We develop a theoretical description, suitable for broadband radiation, which accurately describes the experimental results. We measure the time evolution of the degree of polarization, and directly correlate it with the single-scattering regime in the time domain. Measurements of the evolution of the temporal phase of the radiation demonstrate that the average spectral content depends on the state of polarization. In the case of broadband radiation, this effect distinguishes photons that have been scattered only a few times from those that are propagating diffusively.

Technology-Enabled Active Learning Environments: An Appraisal

ERIC Educational Resources Information Center

Fisher, Kenn

2010-01-01

The recent advent of wireless broadband Internet access and mobile communications devices has provided remarkable opportunities for 21st century blended learning models--simultaneous online and face-to-face--and seriously called into question the industrial-age traditional "egg crate classroom" model of teaching and learning. It has…

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…

Utilization of photovoltaic for broadband satellite communications in rural area of Thailand

NASA Astrophysics Data System (ADS)

Jinayim, Theerawut; Mungkung, Narong; Kasayapanand, Nat

2013-06-01

Electricity, Information and Communication Technologies (ICTs) are very important not only in urban areas but also in rural areas. To provide ICTs service in rural areas, sources of electricity and communication infrastructures must be implemented. Electricity is a major condition due to the fact that all electronic devices needed it in order to power on, so that it is impossible to operate any forms of ICTs in areas where the main national grid line is unavailable. Almost rural areas of Thailand where the main national grid line is unavailable have very good sunlight intensity. Photovoltaic is the most effective renewable energy technologies in those areas for meeting electricity needed in areas that are not connected to the main national grid line. In this paper, the efficiency utilization of photovoltaic as source of electricity for broadband satellite communication systems as well as social and economic impact and quality of life of people in rural areas of Thailand are presented. The results show that most rural communities would be able to universally access to the basic telecommunications services such as internet access and public telephone via satellite communication systems. However, in some field case study, broadband internet access via satellite communication may be unnecessary for some rural communities and the most exactly rural communities needed are electricity for household usage and battery charger.

Telehealth on advanced networks.

PubMed

Wilson, Laurence S; Stevenson, Duncan R; Cregan, Patrick

2010-01-01

We address advanced Internet for complex telehealth applications by reviewing four hospital-based broadband telehealth projects and identifying common threads. These projects were conducted in Australia under a 6-year research project on broadband Internet applications. Each project addressed specific clinical needs and its development was guided by the clinicians involved. Each project was trialed in the field and evaluated against the initial requirements. The four projects covered remote management of a resuscitation team in a district hospital, remote guidance and interpretation of echocardiography, virtual-reality-based instructor-student surgical training, and postoperative outpatient consultations following pediatric surgery. Each was characterized by a high level of interpersonal communication, a high level of clinical expertise, and multiple participants. Each made use of multiple high-quality video and audio links and shared real-time access to clinical data. Four common threads were observed. Each application provided a high level of usability and task focus because the design and use of broadband capability was aimed directly to meet the clinicians' needs. Each used the media quality available over broadband to convey words, gestures, body movements, and facial expressions to support communication and a sense of presence among the participants. Each required a complex information space shared among the participants, including real-time access to stored patient data and real-time interactive access to the patients themselves. Finally, each application supported the social and organizational aspects of their healthcare focus, creating and maintaining relationships between the various participants, and this was done by placing the telehealth application into a wider functioning clinical context. These findings provide evidence for a significantly enhanced role for appropriate telemedicine systems running on advanced networks, in a wider range of clinical applications, more deeply integrated into healthcare systems.

Broadband diffuse optical characterization of elastin for biomedical applications.

PubMed

Konugolu Venkata Sekar, Sanathana; Beh, Joo Sin; Farina, Andrea; Dalla Mora, Alberto; Pifferi, Antonio; Taroni, Paola

2017-10-01

Elastin is a key structural protein of dynamic connective tissues widely found in the extracellular matrix of skin, arteries, lungs and ligaments. It is responsible for a range of diseases related to aging of biological tissues. The optical characterization of elastin can open new opportunities for its investigation in biomedical studies. In this work, we present the absorption spectra of elastin using a broadband (550-1350nm) diffuse optical spectrometer. Distortions caused by fluorescence and finite bandwidth of the laser source on estimated absorption were effectively accounted for in measurements and data analysis and compensated. A comprehensive summary and comparison between collagen and elastin is presented, highlighting distinct features for its accurate quantification in biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

77 FR 38061 - Notice of Public Information Collection Approved by the Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-26

... Information System to assist the Commission in ensuring rapid restoration of communications capabilities after... circuit- switched network infrastructure to broadband networks. The Commission is seeking to extend the... Internet Service Providers. Increasing numbers of consumers, businesses, and government agencies rely on...

National Marrow Donor Program

DTIC Science & Technology

2010-11-05

from power or Internet outages to severe weather. • Received 50 mobile broadband air cards at minimal cost to the organization and ONR to allow for...CLlA CME CMF COG CREG CSS CT CTA DC DHHS-ASPR DIY DKMS DMSO DoD DNA DIR EBMT EM EMDIS ENS ERSI FBI QUARTER PROGRESS REPORT

Disapproving the rule submitted by the Federal Communications Commission with respect to regulating the Internet and broadband industry practices.

THOMAS, 112th Congress

Rep. Walden, Greg [R-OR-2

2011-02-16

Senate - 04/13/2011 Read the second time. Placed on Senate Legislative Calendar under General Orders. Calendar No. 34. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

The Need for Federal Legislation and Regulation Prohibiting Telecommunications and Information Services Discrimination

ERIC Educational Resources Information Center

Strauss, Karen Peltz

2006-01-01

This paper explores the need to adopt legislative and regulatory safeguards to guarantee equal access by people with disabilities to evolving high speed broadband, wireless and Internet-based technologies. Recommendations include: (1) Communications Access--FCC or Congress: Extend the telecommunications accessibility requirements of Section 255 of…

Combination of broadband diffuse optical spectroscopy with magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Merritt, Sean Isaiah

Broadband diffuse optical spectroscopy (DOS) is an emerging optical technique used to measure absorption and scattering of bulk tissue non-invasively within the near-infrared (600--1050 nm). The ultimate aim of my advisors group is for broadband DOS to become an established medical diagnostic technique used clinically on various tissue types including breast, muscle and bone. The specific goal for my research is to use established magnetic resonance (MR) techniques for the purpose of continued development and validation of broadband DOS. The initial studies carried out were a validation of broadband DOS through a direct comparison with MRI. Both techniques are sensitive to signals produced by water and lipids in tissue. There is also sensitivity to blood flow, which MRI measures using exogenous contrast agents and broadband DOS is sensitive through measurement of total hemoglobin content (THC) and tissue oxygen saturation (StO2). These validation studies were compared initially in a rat tumor model in which both techniques were used simultaneously. A qualitative correlation was found between the MR images of water content and blood perfusion compared with the DOS water and THC values. A more quantitative comparison was made between measuring absolute water and lipid content in phantoms and in human tissue, which showed a strong correlation. The in vivo study also validated that broadband DOS was interrogating bone marrow in the tibia. The second half of this thesis is focused on developing new capabilities of broadband DOS and the MRI literature is used as a guide. When a water molecule hydrogen bonds to another molecule, the absorption spectrum in the near-infrared which is due to the vibrational overtone of the OH bond will change. The expected changes were observed in tissue and an algorithm was developed to fit for a tissue bound water parameter. Also, as tissue temperature changes, the fraction of water bound to other water molecules changes and can be used to fit for deep tissue temperature. Preliminary validation of these two techniques is carried out and there appears to be great potential for these methods.

AIRTV: Broadband Direct to Aircraft

NASA Astrophysics Data System (ADS)

Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.

2002-01-01

Airlines have been continuously upgrading their wide-body, long-haul aircraft with IFE (in-flight entertainment) systems that can support from 12 to 24 channels of video entertainment as well as provide the infrastructure to enable in-seat delivery of email and internet services. This is a direct consequence of increased passenger demands for improved in-flight services along with the expectations that broadband delivery systems capable of providing live entertainment (news, sports, financial information, etc.) and high speed data delivery will soon be available. The recent events of Sept. 11 have slowed the airline's upgrade of their IFE systems, but have also highlighted the compelling need for broadband aeronautical delivery systems to include operational and safety information. Despite the impact of these events, it is estimated that by 2005 more than 3000 long haul aircraft (servicing approximately 1 billion passengers annually) will be fully equipped with modern IFE systems. Current aircraft data delivery systems, which use either Inmarsat or NATS, are lacking in bandwidth and consequently are unsuitable to satisfy passenger demands for broadband email/internet services or the airlines' burgeoning data requirements. Present live video delivery services are limited to regional coverage and are not readily expandable to global or multiregional service. Faced with a compelling market demand for high data transport to aircraft, AirTV has been developing a broadband delivery system that will meet both passengers' and airlines' needs. AirTV is a global content delivery system designed to provide a range of video programming and data services to commercial airlines. When AirTV is operational in 2004, it will provide a broadband connection directly to the aircraft, delivering live video entertainment, internet/email service and essential operational and safety data. The system has been designed to provide seamless global service to all airline routes except for those over the poles. The system consists of a constellation of 4 geostationary satellites covering the earth and delivering its signals to the aircraft at S band (2.52 -2.67 GHz). The S-band spectrum is ideal for this application since it is allocated on a primary basis by the ITU for global broadcast service. The AirTV service is expected to begin in 2004 and should be unencumbered by adjacent satellite interference due to near completion of the ITU coordination process. Each satellite will deliver four 20 Mbps QPSK data streams consisting of multiplexed compressed digital video channels and IP data over the full global beam coverage. The 80 Mbps capacity of each satellite will provide approximately 60 video channels while still allocating 40 Mbits to data services. The combined constellation capacity of 320 Mbits will significantly exceed the capacity of any similar existing or currently planned global satellite system. In addition, the simplicity of the 4-satellite approach is the most cost effective means to deliver high bandwidth globally. Return links, which are required for internet service, will be provided through the existing Inmarsat Aero-H system already onboard virtually all long haul aircraft and will provide return data rates from the aircraft as high as 432 kbps. integrated receiver/decoder (IRD) assembly. The phased array antenna, a key technology element, is being developed by AirTV's strategic partner, CMC Electronics. This antenna is a scaled version of CMC's Inmarsat Aero H antenna and is capable of scanning to 5 degrees above the horizon. Wide angle scanning up to 85 degrees from zenith is necessary for aircraft traversing the northernmost latitudes on transoceanic routes. AirTV has designed both the satellite coverage and aircraft antenna performance to ensure that high signal quality is maintained along all non-polar airline routes. AirTV will be the future of aeronautical broadband delivery. It has been designed specifically for global services and uses the ideal spectrum for this application. It will revolutionize the delivery of content to aircraft. This paper will describe the AirTV system and highlight its advanced service capabilities.

Ubiquitous Mobile Technologies and the Transformation of Schooling

ERIC Educational Resources Information Center

Bjerede, Marie; Atkins, Kristin; Dede, Chris

2010-01-01

This article explores how the Internet and mobile broadband technologies that are transforming the work of business professionals may be applied to the work of teachers and students in K-20 schooling, with similarly transformative outcomes. First, they discuss the ways in which ubiquitous mobile technologies are changing 21st century business.…

From Bricks to Clicks: Blurring Classroom/Cyber Lines

ERIC Educational Resources Information Center

Pape, Liz

2006-01-01

In recent years, thanks to the evolution of the Internet, wide availability of classroom computers and increased broadband access, blended learning is emerging as a new tool in the K-12 educational toolkit. Defined as learning that combines online and face-to-face approaches, blended learning is accomplished through the combined use of virtual and…

Pupil Science Learning in Resource-Based e-Learning Environments

ERIC Educational Resources Information Center

So, Wing-mui Winnie; Ching, Ngai-ying Fiona

2011-01-01

With the rapid expansion of broadband Internet connection and availability of high performance yet low priced computers, many countries around the world are advocating the adoption of e-learning, the use of computer technology to improve learning and teaching. The trend of e-learning has urged many teachers to incorporate online resources in their…

Improving Cancer-Related Outcomes with Connected Health - Objective 4

Cancer.gov

The full benefits of connected health cannot be achieved unless everyone in the United States who wants to participate and the organizations that support health and deliver healthcare have adequate access to high-speed Internet service. Access depends both on the availability of broadband service and the resources needed to obtain and maintain service.

76 FR 26199 - Reexamination of Roaming Obligations of Commercial Mobile Radio Service Providers and Other...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-06

... CONTACT: Peter Trachtenberg, Wireless Telecommunications Bureau, (202) 418-7369, e-mail Peter.Trachtenberg... e-mail and wireless broadband Internet access. The rule the Commission adopts today also serves the..., and the availability of data roaming will help ensure the viability of new wireless data network...

Impact of Commercial Search Engines and International Databases on Engineering Teaching and Research

ERIC Educational Resources Information Center

Chanson, Hubert

2007-01-01

For the last three decades, the engineering higher education and professional environments have been completely transformed by the "electronic/digital information revolution" that has included the introduction of personal computer, the development of email and world wide web, and broadband Internet connections at home. Herein the writer compares…

A joint resolution disapproving the rule submitted by the Federal Communications Commission with respect to regulating the Internet and broadband industry practices.

THOMAS, 112th Congress

Sen. Hutchison, Kay Bailey [R-TX

2011-02-16

Senate - 11/10/2011 Motion to proceed to consideration of measure rejected in Senate by Yea-Nay Vote. 46 - 52. Record Vote Number: 200. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

76 FR 68641 - Development of Nationwide Broadband Data To Evaluate Reasonable and Timely Deployment of Advanced...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

... Internet at [email protected] . SUPPLEMENTARY INFORMATION: The Federal Communications Commission has... information unless it displays a currently valid control number. Notwithstanding any other provisions of law... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 1 and 43 [WC Docket No. 07-38; FCC 08-89, 08-148...

Creating Anytime, Anywhere Learning for All Students: Key Elements of a Comprehensive Digital Infrastructure

ERIC Educational Resources Information Center

Thigpen, Kamila

2014-01-01

While connecting the nation's schools and libraries to the internet by modernizing and expanding the federal E-rate program currently dominates education technology efforts, a new report from the Alliance for Excellent Education urges that adequate broadband access be accompanied by a comprehensive "digital infrastructure" that unlocks…

75 FR 67363 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-02

... proceeding were required to file system security statements under the Commission's rules. (Security systems..., including broadband Internet access and interconnected VoIP providers, must file updates to their systems... Commission's rules, the information in the CALEA security system filings and petitions will not be made...

Interactive Distance e-Learning for Isolated Communities: The Policy Footprint

ERIC Educational Resources Information Center

Crump, Stephen; Twyford, Kylie; Littler, Margaret

2008-01-01

This paper provides information on the policy strand of an investigation into the Australian Research Council Linkage research project into "interactive distance e-learning" [IDeL] following the introduction in New South Wales and in the Northern Territory of Australia of satellite-supported two-way broad-band internet services for…

Collaborative Information Technology Center (CITC) for Rural Areas.

ERIC Educational Resources Information Center

Fontenot, Dean; Driskill, David A.

The digital divide remains a formidable issue in rural areas where the only broadband access to the Internet may be at public schools or city governments. As the only locations in rural areas with adequate technological resources, schools, libraries, health facilities, and agricultural extension facilities can be places where citizens learn about…

Life, Liberty and the Pursuit of Broadband

ERIC Educational Resources Information Center

Hart, Michael

2012-01-01

Although the perception of many is that internet access is now nearly ubiquitous, the reality, according to the National Telecommunications and Information Administration, is that somewhere around 30 percent of American homes still do not have it. The NTIA also reports that, while 80 percent of the households in which family income is more than…

Musings on the Internet, Part 2

ERIC Educational Resources Information Center

Cerf, Vinton G.

2004-01-01

In t his article, the author discusses the role of higher education research and development (R&D)--particularly R&D into the issues and problems that industry is less able to explore. In addition to high-speed computer communication, broadband networking efforts, and the use of fiber, a rich service environment is equally important and is…

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies.

PubMed

Konugolu Venkata Sekar, Sanathana; Pagliazzi, Marco; Negredo, Eugènia; Martelli, Fabrizio; Farina, Andrea; Dalla Mora, Alberto; Lindner, Claus; Farzam, Parisa; Pérez-Álvarez, Núria; Puig, Jordi; Taroni, Paola; Pifferi, Antonio; Durduran, Turgut

2016-01-01

Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600-1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care.

In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

PubMed Central

Pagliazzi, Marco; Negredo, Eugènia; Martelli, Fabrizio; Farina, Andrea; Dalla Mora, Alberto; Lindner, Claus; Farzam, Parisa; Pérez-Álvarez, Núria; Puig, Jordi; Taroni, Paola; Pifferi, Antonio; Durduran, Turgut

2016-01-01

Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600–1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care. PMID:27997565

At the Intersection of Networks and Highly Interactive Online Games

NASA Astrophysics Data System (ADS)

Armitage, Grenville

The game industry continues to evolves its techniques for extracting the most realistic 'immersion' experience for players given the vagaries on best-effort Internet service. A key challenge for service providers is understanding the characteristics of traffic imposed on networks by games, and their service quality requirements. Interactive online games are particularly susceptible to the side effects of other non-interactive (or delay- and loss-tolerant) traffic sharing next- generation access links. This creates challenges out toward the edges, where high-speed home LANs squeeze through broadband consumer access links to reach the Internet. In this chapter we identify a range of research work exploring many issues associated with the intersection of highly interactive games and the Internet, and hopefully stimulate some further thinking along these lines.

Face-to-Face vs. Real-Time Clinical Education: No Significant Difference

ERIC Educational Resources Information Center

Mohammed, Y. Q.; Waddington, G.; Donnan, P.

2007-01-01

The main objective of this pilot research project was to determine whether the use of an internet broadband link to stream physiotherapy clinical education workshop proceedings in "real-time" is of equivalent educational value to the traditional face-to-face experience. This project looked at the benefits of using the above technology as…

Open Courseware in Design and Planning Education and Utilization of Distance Education Opportunity: Anadolu University Experience

ERIC Educational Resources Information Center

Halac, Hicran Hanim; Cabuk, Alper

2013-01-01

Depending on the evolving technological possibilities, distance and online education applications have gradually gained more significance in the education system. Regarding the issues, such as advancements in the server services, disc capacity, cloud computing opportunities resulting from the increase in the number of the broadband internet users,…

Interactive Distance e-Learning for Isolated Communities: Starting and Finishing the Jigsaw

ERIC Educational Resources Information Center

Crump, Stephen; Boylan, Colin

2008-01-01

This paper provides information on the background to the two pilot investigations into "interactive distance e-learning" [IDeL] following the introduction in New South Wales and in the Northern Territory of Australia of satellite-supported two-way broad-band internet services for school-age and adult distance education. The context is…

Coding metasurface for broadband microwave scattering reduction with optical transparency.

PubMed

Chen, Ke; Cui, Li; Feng, Yijun; Zhao, Junming; Jiang, Tian; Zhu, Bo

2017-03-06

Metasurfaces have promised great possibilities in full control of the electromagnetic wavefront by spatially manipulating the phase characteristics across the interface. Here, we report a scheme to realize broadband backward scattering reduction through diffusion-like microwave reflection by utilizing a flexible indium-tin-oxide (ITO)-based ultrathin coding metasurface (less than 0.1 wavelength thick) with high optical transparence. The diffusion-like scattering is caused by the destructive interference of the scattered far-field electromagnetic wave, which is further attributed to the randomly distributed reflection phases on the metasurface composed of pre-designed meta-atoms arranged with a computer-generated pseudorandom coding sequence. Both simulation and measurement on fabricated prototype sample have been carried out to validate its performance, demonstrating a polarization-independent broadband (nearly from 8 GHz to 15 GHz) 10 dB scattering reduction with good oblique performance. The excellent performances can also be preserved to conformal cases when the flexible metasurface is uniformly wrapped around a metallic cylinder. The proposed metasurface may create new opportunities to tailor the exotic microwave scattering features with simultaneously high transmittance in visible frequencies, which could provide crucial benefits in many practical uses, such as window and solar panel applications.

Exchanging Medical Information with Eastern Europe through the Internet.

ERIC Educational Resources Information Center

Daniels, Julie K.; Cronje, Ruth J.; Sokolowski, Beth C.

1998-01-01

Interviews foreign Information Coordinators who facilitate exchange of medical information over the Internet between healthcare providers in America and eastern Europe to learn how Internet technologies are being introduced, disseminated, and adopted in their institutions. Applies diffusion of innovations theory for interpretation. Shows technical…

3.5G based mobile remote monitoring system.

PubMed

Bajracharya, Aman; Gale, Timothy J; Stack, Clive R; Turner, Paul

2008-01-01

Low bandwidth has long been a reason for the unsuitability of wireless internet in telemedicine. However with the advent of extended third generation wireless as an economically accessible high speed network, more opportunities are being created in this area of telemedicine. This paper explores the opportunity created by the latest wireless broadband technology for remote monitoring of patients in the home.

Digital Textbooks and Digital Divide in West Virginia: Teachers' Hidden Works

ERIC Educational Resources Information Center

Ravenscroft, Matthew D.

2017-01-01

Digital textbooks are replacing print books in school districts across the United States due to their adaptability for students with special needs, enhanced student interest, and lower cost. This is also true in the rural state of West Virginia which lags the U.S. in broadband Internet saturation. Therefore, the purpose of this study was to…

Human Computer Interaction (HCI) and Internet Residency: Implications for Both Personal Life and Teaching/Learning

ERIC Educational Resources Information Center

Crearie, Linda

2016-01-01

Technological advances over the last decade have had a significant impact on the teaching and learning experiences students encounter today. We now take technologies such as Web 2.0, mobile devices, cloud computing, podcasts, social networking, super-fast broadband, and connectedness for granted. So what about the student use of these types of…

From Sea to Cyberspace: Women's Leadership and Learning around Information and Communication Technologies in Coastal Newfoundland

ERIC Educational Resources Information Center

Clover, Darlene E.

2007-01-01

Due to a moratorium on the cod fishery in 1992, small, isolated coastal villages in Newfoundland suffer increasing unemployment, health problems and threats of re-location by the government. In the hopes of addressing some of these problems, the Burgeo Broadcasting System (BBS) placed video-conferencing and broad-band internet into five small…

Pricing by timing: innovating broadband data plans

NASA Astrophysics Data System (ADS)

Ha, Sangtae; Joe-Wong, Carlee; Sen, Soumya; Chiang, Mung

2012-01-01

Wireless Internet usage is doubling every year. Users are using more of high bandwidth data applications, and the heavy usage concentrates on several peak hours in a day, forcing ISPs to overprovision their networks accordingly. In order to remain profitable, ISPs have been using pricing as a congestion management tool. We review many of such pricing schemes in practice today and argue that they do not solve ISPs' problem of growing data traffic. We believe that dynamic, time-dependent usage pricing, which charges users based on when they access the Internet, can incentivize users to spread out their bandwidth consumption more evenly across different times of the day, thus helping ISPs to overcome the problem of peak congestion. Congestion pricing is not a new idea in itself, but the time for its implementation in data networks has finally arrived. Our key contribution lies in developing new analysis and a fully integrated system architecture, called TUBE (Time-dependent Usage-based Broadband price Engineering) that enables ISPs to implement the proposed TDP plan. The theory, simulation, and system implementation of TUBE system is further complemented with consumer surveys conducted in India and the US, along with preparations for a field trial that is currently underway.

IR GRIN optics: design and fabrication

NASA Astrophysics Data System (ADS)

Gibson, Daniel; Bayya, Shyam; Nguyen, Vinh; Sanghera, Jas; Kotov, Mikhail; McClain, Collin; Deegan, John; Lindberg, George; Unger, Blair; Vizgaitis, Jay

2017-06-01

Infrared (IR) transmitting gradient index (GRIN) materials have been developed for broad-band IR imaging. This material is derived from the diffusion of homogeneous chalcogenide glasses has good transmission for all IR wavebands. The optical properties of the IR-GRIN materials are presented and the fabrication and design methodologies are discussed. Modeling and optimization of the diffusion process is exploited to minimize the deviation of the index profile from the design profile. Fully diffused IR-GRIN blanks with Δn of 0.2 are demonstrated with deviation errors of +/-0.01 refractive index units.

Multi-spectral Metasurface for Different Functional Control of Reflection Waves.

PubMed

Huang, Cheng; Pan, Wenbo; Ma, Xiaoliang; Luo, Xiangang

2016-03-22

Metasurface have recently generated much interest due to its strong manipulation of electromagnetic wave and its easy fabrication compared to bulky metamaterial. Here, we propose the design of a multi-spectral metasurface that can achieve beam deflection and broadband diffusion simultaneously at two different frequency bands. The metasurface is composed of two-layered metallic patterns backed by a metallic ground plane. The top-layer metasurface utilizes the cross-line structures with two different dimensions for producing 0 and π reflection phase response, while the bottom-layer metasurface is realized by a topological morphing of the I-shaped patterns for creating the gradient phase distribution. The whole metasurface is demonstrated to independently control the reflected waves to realize different functions at two bands when illuminated by a normal linear-polarized wave. Both simulation and experimental results show that the beam deflection is achieved at K-band with broadband diffusion at X-Ku band.

Thermally Diffused Al:ZnO Thin Films for Broadband Transparent Conductor.

PubMed

Tong, Chong; Yun, Juhyung; Chen, Yen-Jen; Ji, Dengxin; Gan, Qiaoqiang; Anderson, Wayne A

2016-02-17

Here, we report an approach to realize highly transparent low resistance Al-doped ZnO (AZO) films for broadband transparent conductors. Thin Al films are deposited on ZnO surfaces, followed by thermal diffusion processes, introducing the Al doping into ZnO thin films. By utilizing the interdiffusion of Al, Zn, and O, the chemical state of Al on the surfaces can be converted to a fully oxidized state, resulting in a low sheet resistance of 6.2 Ω/sq and an excellent transparency (i.e., 96.5% at 550 nm and higher than 85% up to 2500 nm), which is superior compared with some previously reported values for indium tin oxide, solution processed AZO, and many transparent conducting materials using novel nanostructures. Such AZO films are also applied as transparent conducting layers for AZO/Si heterojunction solar cells, demonstrating their applications in optoelectronic devices.

Multi-spectral Metasurface for Different Functional Control of Reflection Waves

PubMed Central

Huang, Cheng; Pan, Wenbo; Ma, Xiaoliang; Luo, Xiangang

2016-01-01

Metasurface have recently generated much interest due to its strong manipulation of electromagnetic wave and its easy fabrication compared to bulky metamaterial. Here, we propose the design of a multi-spectral metasurface that can achieve beam deflection and broadband diffusion simultaneously at two different frequency bands. The metasurface is composed of two-layered metallic patterns backed by a metallic ground plane. The top-layer metasurface utilizes the cross-line structures with two different dimensions for producing 0 and π reflection phase response, while the bottom-layer metasurface is realized by a topological morphing of the I-shaped patterns for creating the gradient phase distribution. The whole metasurface is demonstrated to independently control the reflected waves to realize different functions at two bands when illuminated by a normal linear-polarized wave. Both simulation and experimental results show that the beam deflection is achieved at K-band with broadband diffusion at X-Ku band. PMID:27001206

A broadband LED source in visible to short-wave-infrared wavelengths for spectral tumor diagnostics

NASA Astrophysics Data System (ADS)

Hayashi, Daiyu; van Dongen, Anne Marie; Boerekamp, Jack; Spoor, Sandra; Lucassen, Gerald; Schleipen, Jean

2017-06-01

Various tumor types exhibit the spectral fingerprints in the absorption and reflection spectra in visible and especially in near- to short-wave-infrared wavelength ranges. For the purpose of spectral tumor diagnostics by means of diffuse reflectance spectroscopy, we developed a broadband light emitting diode (LED) source consisting of a blue LED for optical excitation, Lu3Al5O12:Ce3+,Cr3+ luminescent garnet for visible to near infrared emissions, and Bismuth doped GeO2 luminescent glass for near-infrared to short-wave infrared emissions. It emits broad-band light emissions continuously in 470-1600 nm with a spectral gap at 900-1000 nm. In comparison to the currently available broadband light sources like halogen lamps, high-pressure discharge lamps and super continuum lasers, the light sources of this paper has significant advantages for spectral tissue diagnostics in high-spectral stability, improved light coupling to optical fibers, potential in low light source cost and enabling battery-drive.

Innovation in sexually transmitted disease and HIV prevention: internet and mobile phone delivery vehicles for global diffusion.

PubMed

Swendeman, Dallas; Rotheram-Borus, Mary Jane

2010-03-01

Efficacious behavioral interventions and practices have not been universally accepted, adopted, or diffused by policy makers, administrators, providers, advocates, or consumers. Biomedical innovations for sexually transmitted disease (STD) and HIV prevention have been embraced but their effectiveness is hindered by behavioral factors. Behavioral interventions are required to support providers and consumers for adoption and diffusion of biomedical innovations, protocol adherence, and sustained prevention for other STDs. Information and communication technology such as the Internet and mobile phones can deliver behavioral components for STD/HIV prevention and care to more people at less cost. Recent innovations in STD/HIV prevention with information and communication technology-mediated behavioral supports include STD/HIV testing and partner interventions, behavioral interventions, self-management, and provider care. Computer-based and Internet-based behavioral STD/HIV interventions have demonstrated efficacy comparable to face-to-face interventions. Mobile phone STD/HIV interventions using text-messaging are being broadly utilized but more work is needed to demonstrate efficacy. Electronic health records and care management systems can improve care, but interventions are needed to support adoption. Information and communication technology is rapidly diffusing globally. Over the next 5-10 years smart-phones will be broadly disseminated, connecting billions of people to the Internet and enabling lower cost, highly engaging, and ubiquitous STD/HIV prevention and treatment support interventions.

Development of a hybrid broadband NIRS/diffusion correlation spectroscopy system to monitor preterm brain injury (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rajaram, Ajay; St. Lawrence, Keith; Diop, Mamadou

2017-02-01

In Canada, 8% of births occur prematurely. Preterm infants weighing less than 1500g are at a high risk of neurodevelopmental impairment: 5-10% develop major disabilities such as cerebral palsy and 40-50% show other cognitive and behavioural deficits. The brain is vulnerable to periods of low cerebral blood flow (CBF) that can impair energy metabolism and cause tissue damage. There is, therefore, a need for an efficient neuromonitoring system to alert the neonatal intensive care team to clinically significant changes in CBF and metabolism, before injury occurs. Optical technologies offer safe, non-invasive, and cost-effective methods for neuromonitoring. Cerebral oxygen saturation (ScO2) can be measured by exploiting the absorption properties of hemoglobin though Near-Infrared Spectroscopy (NIRS), and Diffuse Correlation Spectroscopy (DCS) can monitor CBF by tracking red blood cells. These measures can be combined to describe metabolism, a key indicator of tissue viability. In this study we present the development and testing of a hybrid broadband NIRS/DCS neuromonitor. This system is novel in its ability to simultaneously acquire broadband NIRS and DCS signals, providing a truly real-time measure of metabolism. Narrow bandpass and notch filters have been incorporated to diminish light contamination between the two modalities, preferentially filtering out each source from the opposing detector, allowing for an accurate measure of ScO2, CBF, and metabolism. With a broadband NIRS/DCS system, a real-time measure of CBF and metabolism within the developing brain can aid clinicians in monitoring events that precede brain injury, ultimately leading to better clinical outcomes.

Analysis of temporal decay of diffuse broadband sound fields in enclosures by decomposition in powers of an absorption parameter

NASA Astrophysics Data System (ADS)

Bliss, Donald; Franzoni, Linda; Rouse, Jerry; Manning, Ben

2005-09-01

An analysis method for time-dependent broadband diffuse sound fields in enclosures is described. Beginning with a formulation utilizing time-dependent broadband intensity boundary sources, the strength of these wall sources is expanded in a series in powers of an absorption parameter, thereby giving a separate boundary integral problem for each power. The temporal behavior is characterized by a Taylor expansion in the delay time for a source to influence an evaluation point. The lowest-order problem has a uniform interior field proportional to the reciprocal of the absorption parameter, as expected, and exhibits relatively slow exponential decay. The next-order problem gives a mean-square pressure distribution that is independent of the absorption parameter and is primarily responsible for the spatial variation of the reverberant field. This problem, which is driven by input sources and the lowest-order reverberant field, depends on source location and the spatial distribution of absorption. Additional problems proceed at integer powers of the absorption parameter, but are essentially higher-order corrections to the spatial variation. Temporal behavior is expressed in terms of an eigenvalue problem, with boundary source strength distributions expressed as eigenmodes. Solutions exhibit rapid short-time spatial redistribution followed by long-time decay of a predominant spatial mode.

Universities as Hubs for Next-Generation Networks: A Model for Universities to Spur 21st Century Internet Access and Innovation in Their Communities

ERIC Educational Resources Information Center

Lennett, Benjamin; Morris, Sarah J.; Byrum, Greta

2012-01-01

Based on a request for information (RFI) submitted to The University Community Next Generation Innovation Project (Gig.U), the paper describes a model for universities to develop next generation broadband infrastructure in their communities. In the our view universities can play a critical role in spurring next generation networks into their…

Time-dependent diffuse reflectance spectroscopy for in vivo characterization of pediatric epileptogenic brain lesions

NASA Astrophysics Data System (ADS)

Oh, Sanghoon; Ragheb, John; Bhatia, Sanjiv; Sandberg, David; Johnson, Mahlon; Fernald, Bradley; Lin, Wei-Chiang

2008-02-01

Optical spectroscopy for in vivo tissue diagnosis is performed traditionally in a static manner; a snap shot of the tissue biochemical and morphological characteristics is captured through the interaction between light and the tissue. This approach does not capture the dynamic nature of a living organ, which is critical to the studies of brain disorders such as epilepsy. Therefore, a time-dependent diffuse reflectance spectroscopy system with a fiber-optic probe was designed and developed. The system was designed to acquire broadband diffuse reflectance spectra (240 ~ 932 nm) at an acquisition rate of 33 Hz. The broadband spectral acquisition feature allows simultaneous monitoring of various physiological characteristics of tissues. The utility of such a system in guiding pediatric epilepsy surgery was tested in a pilot clinical study including 13 epilepsy patients and seven brain tumor patients. The control patients were children undergoing suregery for brain tumors in which measurements were taken from normal brain exposed during the surgery. Diffuse reflectance spectra were acquired for 12 seconds from various parts of the brain of the patients during surgery. Recorded spectra were processed and analyzed in both spectral and time domains to gain insights into the dynamic changes in, for example, hemodynamics of the investigated brain tissue. One finding from this pilot study is that unsynchronized alterations in local blood oxygenation and local blood volume were observed in epileptogenic cortex. These study results suggest the advantage of using a time-dependent diffuse reflectance spectroscopy system to study epileptogenic brain in vivo.

Resonant scattering of energetic electrons in the outer radiation belt by HAARP-induced ELF/VLF waves

NASA Astrophysics Data System (ADS)

Chang, Shanshan; Zhu, Zhengping; Ni, Binbin; Cao, Xing; Luo, Weihua

2016-10-01

Several extremely low-frequency (ELF)/very low-frequency (VLF) wave generation experiments have been performed successfully at High-Frequency Active Auroral Research Program (HAARP) heating facility and the artificial ELF/VLF signals can leak into the outer radiation belt and contribute to resonant interactions with energetic electrons. Based on the artificial wave properties revealed by many of in situ observations, we implement test particle simulations to evaluate the effects of energetic electron resonant scattering driven by the HAARP-induced ELF/VLF waves. The results indicate that for both single-frequency/monotonic wave and multi-frequency/broadband waves, the behavior of each electron is stochastic while the averaged diffusion effect exhibits temporal linearity in the wave-particle interaction process. The computed local diffusion coefficients show that, the local pitch-angle scattering due to HARRP-induced single-frequency ELF/VLF whistlers with an amplitude of ∼10 pT can be intense near the loss cone with a rate of ∼10-2 rad2 s-1, suggesting the feasibility of HAARP-induced ELF/VLF waves for removal of outer radiation belt energetic electrons. In contrast, the energy diffusion of energetic electrons is relatively weak, which confirms that pitch-angle scattering by artificial ELF/VLF waves can dominantly lead to the precipitation of energetic electrons. Moreover, diffusion rates of the discrete, broadband waves, with the same amplitude of each discrete frequency as the monotonic waves, can be much larger, which suggests that it is feasible to trigger a reasonable broadband wave instead of the monotonic wave to achieve better performance of controlled precipitation of energetic electrons. Moreover, our test particle scattering simulation show good agreement with the predictions of the quasi-linear theory, confirming that both methods are applied to evaluate the effects of resonant interactions between radiation belt electrons and artificially generated discrete ELF/VLF waves.

Projecting the impact of a broadband communication infrastructure on printing, publishing and advertising

NASA Astrophysics Data System (ADS)

Smith, Ted

1994-11-01

A broadband communication infrastructure (over 150 megabits per second), deployed almost everywhere outside the third world within 20 years, is a common planning assumption of governments, communication carriers, and information providers. The "structure" of this infrastructure has been variously projected as being that of the telephone network, the cable system, or the Internet. An argument is made that the telephone model, with features borrowed from the other two, will prevail. This model is used to project broad features of printing, publishing, and advertising. In support of this projection, printing is modeled purposefully, a document is printed to either archive it, give it to someone else, or use it (read, mark up, take along, etc.). In the broadband future, only the last is sustainable. Publishing is modeled as a four-stage chain of commerce from creator to buyer. The progress of both the document and its chain of payments is considered today and in the broadband scenario. Finally, advertising today and tomorrow is modeled as a 2x2x2 cube. One dimension contrasts the "notify/inform" and "persuade" aspects of advertising; another contrasts the consumer's role as passive recipient vs. active controller of what s/he hears and sees; the third views the institution of advertising as reflecting or setting societal values.

Internet Search Patterns of Human Immunodeficiency Virus and the Digital Divide in the Russian Federation: Infoveillance Study

PubMed Central

Quinn, Casey; Hercz, Daniel; Gillespie, James A

2013-01-01

Background Human immunodeficiency virus (HIV) is a serious health problem in the Russian Federation. However, the true scale of HIV in Russia has long been the subject of considerable debate. Using digital surveillance to monitor diseases has become increasingly popular in high income countries. But Internet users may not be representative of overall populations, and the characteristics of the Internet-using population cannot be directly ascertained from search pattern data. This exploratory infoveillance study examined if Internet search patterns can be used for disease surveillance in a large middle-income country with a dispersed population. Objective This study had two main objectives: (1) to validate Internet search patterns against national HIV prevalence data, and (2) to investigate the relationship between search patterns and the determinants of Internet access. Methods We first assessed whether online surveillance is a valid and reliable method for monitoring HIV in the Russian Federation. Yandex and Google both provided tools to study search patterns in the Russian Federation. We evaluated the relationship between both Yandex and Google aggregated search patterns and HIV prevalence in 2011 at national and regional tiers. Second, we analyzed the determinants of Internet access to determine the extent to which they explained regional variations in searches for the Russian terms for “HIV” and “AIDS”. We sought to extend understanding of the characteristics of Internet searching populations by data matching the determinants of Internet access (age, education, income, broadband access price, and urbanization ratios) and searches for the term “HIV” using principal component analysis (PCA). Results We found generally strong correlations between HIV prevalence and searches for the terms “HIV” and “AIDS”. National correlations for Yandex searches for “HIV” were very strongly correlated with HIV prevalence (Spearman rank-order coefficient [rs]=.881, P≤.001) and strongly correlated for “AIDS” (rs=.714, P≤.001). The strength of correlations varied across Russian regions. National correlations in Google for the term “HIV” (rs=.672, P=.004) and “AIDS” (rs=.584, P≤.001) were weaker than for Yandex. Second, we examined the relationship between the determinants of Internet access and search patterns for the term “HIV” across Russia using PCA. At the national level, we found Principal Component 1 loadings, including age (-0.56), HIV search (-0.533), and education (-0.479) contributed 32% of the variance. Principal Component 2 contributed 22% of national variance (income, -0.652 and broadband price, -0.460). Conclusions This study contributes to the methodological literature on search patterns in public health. Based on our preliminary research, we suggest that PCA may be used to evaluate the relationship between the determinants of Internet access and searches for health problems beyond high-income countries. We believe it is in middle-income countries that search methods can make the greatest contribution to public health. PMID:24220250

The development of network infrastructure in rural areas and problems in applying IT to the medical field.

PubMed

Ooe, Yosuke; Anamizu, Hiromitsu; Tatsumi, Haruyuki; Tanaka, Hiroshi

2008-07-01

The financial condition of the Japanese health insurance system is said to be compounded with the aging of the population. The government argues that the application of IT and networking is required in order to streamline health care services while avoiding its collapse. The Internet environment has been furnished with broadband connection and multimedia in the span of one year or shorter, and is becoming more and more convenient. It is true that the Internet is now a part of Tokyo's infrastructure along with electricity and water supply, as it is the center of politics. However, in local cities, development of the Internet environment is still insufficient. In order to use the network as a common infrastructure at health care facilities, we need to be aware of this digital divide. This study investigated the development status of network infrastructure in regional cities.

Telepsychiatry: assessment of televideo psychiatric interview reliability with present- and next-generation internet infrastructures.

PubMed

Yoshino, A; Shigemura, J; Kobayashi, Y; Nomura, S; Shishikura, K; Den, R; Wakisaka, H; Kamata, S; Ashida, H

2001-09-01

We assessed the reliability of remote video psychiatric interviews conducted via the internet using narrow and broad bandwidths. Televideo psychiatric interviews conducted with 42 in-patients with chronic schizophrenia using two bandwidths (narrow, 128 kilobits/s; broad, 2 megabits/s) were assessed in terms of agreement with face-to-face interviews in a test-retest fashion. As a control, agreement was assessed between face-to-face interviews. Psychiatric symptoms were rated using the Oxford version of the Brief Psychiatric Rating Scale (BPRS), and agreement between interviews was estimated as the intraclass correlation coefficient (ICC). The ICC was significantly lower in the narrow bandwidth than in the broad bandwidth and the control for both positive symptoms score and total score. While reliability of televideo psychiatric interviews is insufficient using the present narrow-band internet infrastructure, the next generation of infrastructure (broad-band) may permit reliable diagnostic interviews.

Determination of plate wave velocities and diffuse field decay rates with braod-band acousto-ultrasonic signals

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1993-01-01

Lowest symmetric and lowest antisymmetric plate wave modes were excited and identified in broad-band acousto-ultrasonic (AU) signals collected from various high temperature composite materials. Group velocities have been determined for these nearly nondispersive modes. An algorithm has been developed and applied to determine phase velocities and hence dispersion curves for the frequency ranges of the broad-band pulses. It is demonstrated that these data are sensitive to changes in the various stiffness moduli of the materials, in agreement by analogy, with the theoretical and experimental results of Tang and Henneke on fiber reinforced polymers. Diffuse field decay rates have been determined in the same specimen geometries and AU configuration as for the plate wave measurements. These decay rates are of value in assessing degradation such as matrix cracking in ceramic matrix composites. In addition, we verify that diffuse field decay rates respond to fiber/matrix interfacial shear strength and density in ceramic matrix composites. This work shows that velocity/stiffness and decay rate measurements can be obtained in the same set of AU experiments for characterizing materials and in specimens with geometries useful for mechanical measurements.

Self-organized broadband light trapping in thin film amorphous silicon solar cells.

PubMed

Martella, C; Chiappe, D; Delli Veneri, P; Mercaldo, L V; Usatii, I; Buatier de Mongeot, F

2013-06-07

Nanostructured glass substrates endowed with high aspect ratio one-dimensional corrugations are prepared by defocused ion beam erosion through a self-organized gold (Au) stencil mask. The shielding action of the stencil mask is amplified by co-deposition of gold atoms during ion bombardment. The resulting glass nanostructures enable broadband anti-reflection functionality and at the same time ensure a high efficiency for diffuse light scattering (Haze). It is demonstrated that the patterned glass substrates exhibit a better photon harvesting than the flat glass substrate in p-i-n type thin film a-Si:H solar cells.

Solar Radiometric Data Quality Assessment of SIRS, SKYRAD and GNDRAD Measurements (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habte, A.; Stoffel, T.; Reda, I.

2014-03-01

Solar radiation is the driving force for the earth's weather and climate. Understanding the elements of this dynamic energy balance requires accurate measurements of broadband solar irradiance. Since the mid-1990's the ARM Program has deployed pyrheliometers and pyranometers for the measurement of direct normal irradiance (DNI), global horizontal irradiance (GHI), diffuse horizontal irradiance (DHI), and upwelling shortwave (US) radiation at permanent and mobile field research sites. This poster summarizes the basis for assessing the broadband solar radiation data available from the SIRS, SKYRAD, and GNDRAD measurement systems and provides examples of data inspections.

Internet Diffusion and Adoption within Arab-Palestinian Society in Israel

ERIC Educational Resources Information Center

Ganayem, Asmaa N.

2012-01-01

This study aims to explore the nature of Internet access and use within Arab-Palestinian society in Israel. The research focuses on two points: (i) examining the pace of Internet growth during the last decade and studying the nature of the digital gaps within the studied society in a specific time, (ii) studying the extend of the effect of…

On-Demand Grades: The Effect of Online Grade Book Access on Student Mastery and Performance Goal Orientations, Grade Orientation, Academic Self Efficacy, and Grades

ERIC Educational Resources Information Center

Seldow, Adam Lowell

2010-01-01

With the widespread growth of broadband Internet access, teachers, and in many cases, schools and school districts are transitioning from traditional paper-based grade books to student accessible online (Web-based) grade books. Online grade books offer students 24/7, on demand access to grades and various other student data, and have the potential…

The Impact of eBooks on the Reading Motivation and Reading Skills of Children and Young People: A Rapid Literature Review

ERIC Educational Resources Information Center

Picton, Irene

2014-01-01

While ebooks have been around for many years, recent rapid improvements in the versatility and affordability of e-readers and tablets, along with increased access to broadband internet, have lead to a dramatic rise in household ownership of these devices. Between 2012 and 2013, the proportion of children responding to the National Literacy Trust's…

Multinational Experiment 7. Protecting Access to Space: Presentation to Senior Leaders

DTIC Science & Technology

2013-07-08

Multinational Experiment 7: Outcome 3: Space Access Briefing to SLS 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...operations Consequence management Ship status during search & rescue Tele-medicine Broadband internet TV signal distribution Satellite radio Rural...military-usage • Significant economic & societal consequences Access to space at risk • Current approach unsustainable • Broad range of threats

What It Has or What It Does Not Have? Signposts from US Data for Rural Children's Digital Access to Informal Learning

ERIC Educational Resources Information Center

Mardis, Marcia A.

2013-01-01

A fifth of US children live in rural areas with limited access to the informal learning opportunities available to their metropolitan counterparts. High-speed broadband internet access can be an important vehicle for delivering opportunities at home and outside of the classroom. In an attempt to explore what current data say about children's…

Diffusion-weighted MRI measures suggest increased white-matter integrity in Internet gaming disorder: Evidence from the comparison with recreational Internet game users.

PubMed

Dong, Guangheng; Wu, Lingdan; Wang, Ziliang; Wang, Yifan; Du, Xiaoxia; Potenza, Marc N

2018-06-01

Several studies have suggested that Internet gaming disorder (IGD) is related to altered brain white matter integrity. However, seeming inconsistencies exist and may reflect comparison groups not matched well for certain gaming characteristics. In order to address this possible concern, we recruited in the present study individuals with recreational Internet game use (RGU) comprised of individuals who spend similar amounts of time as IGD subjects playing online games without developing IGD. Diffusion tensor imaging data were collected from 42 IGD and 44 RGU subjects. Whole-brain comparisons showed that IGD subjects demonstrated increased fractional anisotropy (FA) in the bilateral anterior thalamic radiation, anterior limb of the internal capsule, bilateral corticospinal tract, bilateral inferior fronto-occipital fasciculus, corpus callosum, and bilateral inferior longitudinal fasciculus. In addition, Internet-addiction severity was positively correlated with FA values. Taken together, we conclude that IGD is associated with measures of increased white-matter integrity in tracts linking reward circuitry and sensory and motor control systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Performance assessment of diffuse optical spectroscopic imaging instruments in a 2-year multicenter breast cancer trial

NASA Astrophysics Data System (ADS)

Leproux, Anaïs; O'Sullivan, Thomas D.; Cerussi, Albert; Durkin, Amanda; Hill, Brian; Hylton, Nola; Yodh, Arjun G.; Carp, Stefan A.; Boas, David; Jiang, Shudong; Paulsen, Keith D.; Pogue, Brian; Roblyer, Darren; Yang, Wei; Tromberg, Bruce J.

2017-12-01

We present a framework for characterizing the performance of an experimental imaging technology, diffuse optical spectroscopic imaging (DOSI), in a 2-year multicenter American College of Radiology Imaging Network (ACRIN) breast cancer study (ACRIN-6691). DOSI instruments combine broadband frequency-domain photon migration with time-independent near-infrared (650 to 1000 nm) spectroscopy to measure tissue absorption and reduced scattering spectra and tissue hemoglobin, water, and lipid composition. The goal of ACRIN-6691 was to test the effectiveness of optically derived imaging endpoints in predicting the final pathologic response of neoadjuvant chemotherapy (NAC). Sixty patients were enrolled over a 2-year period at participating sites and received multiple DOSI scans prior to and during 3- to 6-month NAC. The impact of three sources of error on accuracy and precision, including different operators, instruments, and calibration standards, was evaluated using a broadband reflectance standard and two different solid tissue-simulating optical phantoms. Instruments showed <0.0010 mm-1 (10.3%) and 0.06 mm-1 (4.7%) deviation in broadband absorption and reduced scattering, respectively, over the 2-year duration of ACRIN-6691. These variations establish a useful performance criterion for assessing instrument stability. The proposed procedures and tests are not limited to DOSI; rather, they are intended to provide methods to characterize performance of any instrument used in translational optical imaging.

Defect imaging for plate-like structures using diffuse field.

PubMed

Hayashi, Takahiro

2018-04-01

Defect imaging utilizing a scanning laser source (SLS) technique produces images of defects in a plate-like structure, as well as spurious images occurring because of resonances and reverberations within the specimen. This study developed defect imaging by the SLS using diffuse field concepts to reduce the intensity of spurious images, by which the energy of flexural waves excited by laser can be estimated. The experimental results in the different frequency bandwidths of excitation waves and in specimens with different attenuation proved that clearer images of defects are obtained in broadband excitation using a chirp wave and in specimens with low attenuation, which produce diffuse fields easily.

Broadband and scalable mobile satellite communication system for future access networks

NASA Astrophysics Data System (ADS)

Ohata, Kohei; Kobayashi, Kiyoshi; Nakahira, Katsuya; Ueba, Masazumi

2005-07-01

Due to the recent market trends, NTT has begun research into next generation satellite communication systems, such as broadband and scalable mobile communication systems. One service application objective is to provide broadband Internet access for transportation systems, temporal broadband access networks and telemetries to remote areas. While these are niche markets the total amount of capacity should be significant. We set a 1-Gb/s total transmission capacity as our goal. Our key concern is the system cost, which means that the system should be unified system with diversified services and not tailored for each application. As satellites account for a large portion of the total system cost, we set the target satellite size as a small, one-ton class dry mass with a 2-kW class payload power. In addition to the payload power and weight, the mobile satellite's frequency band is extremely limited. Therefore, we need to develop innovative technologies that will reduce the weight and maximize spectrum and power efficiency. Another challenge is the need for the system to handle up to 50 dB and a wide data rate range of other applications. This paper describes the key communication system technologies; the frequency reuse strategy, multiplexing scheme, resource allocation scheme, and QoS management algorithm to ensure excellent spectrum efficiency and support a variety of services and quality requirements in the mobile environment.

Abuse of Customer Premise Equipment and Recommended Actions

DTIC Science & Technology

2014-08-07

as reflectors. Descriptions of hacks and control of CPE are more difficult to provide, as such operations are more clandestine. DNS changer provides...connected to broadband Internet, as of July 2013. 7 In the United States, about 84% of those connections have a local home network, such as WiFi . 8...with 324 million WiFi -enabled consumer electronics devices shipped during 2013 in the United States alone. 10 Thus if there were a systematic

DICOM image secure communications with Internet protocols IPv6 and IPv4.

PubMed

Zhang, Jianguo; Yu, Fenghai; Sun, Jianyong; Yang, Yuanyuan; Liang, Chenwen

2007-01-01

Image-data transmission from one site to another through public network is usually characterized in term of privacy, authenticity, and integrity. In this paper, we first describe a general scenario about how image is delivered from one site to another through a wide-area network (WAN) with security features of data privacy, integrity, and authenticity. Second, we give the common implementation method of the digital imaging and communication in medicine (DICOM) image communication software library with IPv6/IPv4 for high-speed broadband Internet by using open-source software. Third, we discuss two major security-transmission methods, the IP security (IPSec) and the secure-socket layer (SSL) or transport-layer security (TLS), being used currently in medical-image-data communication with privacy support. Fourth, we describe a test schema of multiple-modality DICOM-image communications through TCP/IPv4 and TCP/IPv6 with different security methods, different security algorithms, and operating systems, and evaluate the test results. We found that there are tradeoff factors between choosing the IPsec and the SSL/TLS-based security implementation of IPv6/IPv4 protocols. If the WAN networks only use IPv6 such as in high-speed broadband Internet, the choice is IPsec-based security. If the networks are IPv4 or the combination of IPv6 and IPv4, it is better to use SSL/TLS security. The Linux platform has more security algorithms implemented than the Windows (XP) platform, and can achieve better performance in most experiments of IPv6 and IPv4-based DICOM-image communications. In teleradiology or enterprise-PACS applications, the Linux operating system may be the better choice as peer security gateways for both the IPsec and the SSL/TLS-based secure DICOM communications cross public networks.

Creating and Diffusing a Technology Champion Course

ERIC Educational Resources Information Center

Granitz, Neil; Hugstad, Paul

2004-01-01

Excitement has been generated for using Internet technology as a vehicle to further numerous educational objectives, including enhanced student learning, greater integration of business school functional areas, and increased job market relevance. This article discusses how the Introductory Internet Marketing course can be positioned as a…

Worldwide Ocean Optics Database (WOOD)

DTIC Science & Technology

2001-09-30

user can obtain values computed from empirical algorithms (e.g., beam attenuation estimated from diffuse attenuation and backscatter data). Error ...from empirical algorithms (e.g., beam attenuation estimated from diffuse attenuation and backscatter data). Error estimates will also be provided for...properties, including diffuse attenuation, beam attenuation, and scattering. The database shall be easy to use, Internet accessible, and frequently updated

Mapping Mainstream and Fringe Medicine on the Internet.

ERIC Educational Resources Information Center

Evans, William

2001-01-01

Describes a system that monitors Internet discussion groups and Web sites for evidence that public interest in herbal remedies is outpacing available scientific evidence regarding herbal remedies. Using content analysis and bibliometric techniques this system can identify emerging unorthodox practices and can map the diffusion of health-related…

``The Legal Bit's in Russian'': Making Sense of Downloaded Music

NASA Astrophysics Data System (ADS)

Kibby, Marjorie D.

Peer-to-peer sharing of music files grew in the face of consumer dissatisfaction with the compact disc and the absence of any real alternative. Many users were more or less “forced” to turn to illegal file sharing to access single tracks, back catalogues, and niche genres. Recently the almost simultaneous arrival of broadband internet and the iPod has seen music downloading become a respectable activity and a multi-billion dollar industry.

The Role of Networks in Cloud Computing

NASA Astrophysics Data System (ADS)

Lin, Geng; Devine, Mac

The confluence of technology advancements and business developments in Broadband Internet, Web services, computing systems, and application software over the past decade has created a perfect storm for cloud computing. The "cloud model" of delivering and consuming IT functions as services is poised to fundamentally transform the IT industry and rebalance the inter-relationships among end users, enterprise IT, software companies, and the service providers in the IT ecosystem (Armbrust et al., 2009; Lin, Fu, Zhu, & Dasmalchi, 2009).

Efficiency analysis on platform over the top (OTT) to deploy content and applications (edutainment) in digital television on optical network link

NASA Astrophysics Data System (ADS)

Puche, William S.; Sierra, Javier E.; Moreno, Gustavo A.

2014-08-01

The convergence of new technologies in the digital world has made devices with internet connectivity such as televisions, smatphone, Tablet, Blu-ray, game consoles, among others, to increase more and more. Therefore the major research centers are in the task of improving the network performance to mitigate the bottle neck phenomenon regarding capacity and high transmission rates in information and data. The implementation of standard HbbTV (Hybrid Broadcast Broadband TV), and technological platforms OTT (Over the Top), capable of distributing video, audio, TV, and other Internet services via devices connected directly to the cloud. Therefore a model to improve the transmission capacity required by content distribution networks (CDN) for online TV, with high-capacity optical networks is proposed.

Wavefront sensing with a thin diffuser

NASA Astrophysics Data System (ADS)

Berto, Pascal; Rigneault, Hervé; Guillon, Marc

2017-12-01

We propose and implement a broadband, compact, and low-cost wavefront sensing scheme by simply placing a thin diffuser in the close vicinity of a camera. The local wavefront gradient is determined from the local translation of the speckle pattern. The translation vector map is computed thanks to a fast diffeomorphic image registration algorithm and integrated to reconstruct the wavefront profile. The simple translation of speckle grains under local wavefront tip/tilt is ensured by the so-called "memory effect" of the diffuser. Quantitative wavefront measurements are experimentally demonstrated both for the few first Zernike polynomials and for phase-imaging applications requiring high resolution. We finally provided a theoretical description of the resolution limit that is supported experimentally.

Based new WiMax simulation model to investigate Qos with OPNET modeler in sheduling environment

NASA Astrophysics Data System (ADS)

Saini, Sanju; Saini, K. K.

2012-11-01

WiMAX stands for World Interoperability for Microwave Access. It is considered a major part of broadband wireless network having the IEEE 802.16 standard. WiMAX provides innovative, fixed as well as mobile platforms for broadband internet access anywhere anytime with different transmission modes. The results show approximately equal load and throughput while the delay values vary among the different Base Stations Introducing the various type of scheduling algorithm, like FIFO,PQ,WFQ, for comparison of four type of scheduling service, with its own QoS needs and also introducing OPNET modeler support for Worldwide Interoperability for Microwave Access (WiMAX) network. The simulation results indicate the correctness and the effectiveness of this algorithm. This paper presents a WiMAX simulation model designed with OPNET modeler 14 to measure the delay, load and the throughput performance factors.

Evaluation of arctic broadband surface radiation measurements

NASA Astrophysics Data System (ADS)

Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Nievergall, O.; Wendell, J.; Albee, R.

2011-08-01

The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

The Association of Patient Factors, Digital Access, and Online Behavior on Sustained Patient Portal Use: A Prospective Cohort of Enrolled Users.

PubMed

Woods, Susan S; Forsberg, Christopher W; Schwartz, Erin C; Nazi, Kim M; Hibbard, Judith H; Houston, Thomas K; Gerrity, Martha

2017-10-17

As electronic health records and computerized workflows expand, there are unprecedented opportunities to digitally connect with patients using secure portals. To realize the value of patient portals, initial reach across populations will need to be demonstrated, as well as sustained usage over time. The study aim was to identify patient factors associated with short-term and long-term portal usage after patients registered to access all portal functions. We prospectively followed a cohort of patients at a large Department of Veterans Affairs (VA) health care facility who recently completed identity proofing to use the VA patient portal. Information collected at baseline encompassed patient factors potentially associated with portal usage, including: demographics, Internet access and use, health literacy, patient activation, and self-reported health conditions. The primary outcome was the frequency of portal log-ins during 6-month and 18-month time intervals after study enrollment. A total of 270 study participants were followed prospectively. Almost all participants (260/268, 97.0%) reported going online, typically at home (248/268, 92.5%). At 6 months, 84.1% (227/270) of participants had visited the portal, with some variation in usage across demographic and health-related subgroups. There were no significant differences in portal log-ins by age, gender, education, marital status, race/ethnicity, distance to a VA facility, or patient activation measure. Significantly higher portal usage was seen among participants using high-speed broadband at home, greater self-reported ability using the Internet, and routinely going online. By 18 months, 91% participants had logged in to the portal, and no significant associations were found between usage and demographics, health status, or patient activation. When examining portal activity between 6 and 18 months, patients who were infrequent or high portal users remained in those categories, respectively. Short-term and long-term portal usage was associated with having broadband at home, high self-rated ability when using the Internet, and overall online behavior. Digital inclusion, or ready access to the Internet and digital skills, appears to be a social determinant in patient exposure to portal services. ©Susan S Woods, Christopher W Forsberg, Erin C Schwartz, Kim M Nazi, Judith H Hibbard, Thomas K Houston, Martha Gerrity. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 17.10.2017.

Global ring satellite communications system for future broadband network

NASA Astrophysics Data System (ADS)

Iida, Takashi; Suzuki, Yoshiaki; Arimoto, Yoshinori; Akaishi, Akira

2005-04-01

The purpose of this paper is to examine a cost model of a global ring satellite communications system as a 2G-satellite (second generation Internet satellite) for the future Internet satellite, whose capacity is around 120 Gbps. The authors proposed the future needs of research and development of communications satellite for the next 30 years and also proposed the approach of three generations for the future Internet satellites. First, the paper reviews and updates the original proposal for the future needs of communications satellite, considering the recent development of the quantum communication technology. It also examines the communications satellite applicability for bridging the digital divide in the Asia-Oceania as an example. The paper clarifies this possibility of communications satellite by showing various relationships among Internet penetration, land area, population growth, etc. Second, the cost of the global ring satellite is examined. The user terminal is considered as a combination of an earth terminal and wireless local area network for a user community. This paper shows that the global ring satellite has a possibility of a good cost-competitiveness to the terrestrial system because of the global communications system can be configured only by satellite system.

Evidence-based decision making and asthma in the internet age: the tools of the trade.

PubMed

Jadad, A R

2002-01-01

At the dawn of the Information Age, the practice of evidence-based decision making (EBDM) is still hindered by many important barriers related to the decision makers, to the evidence per se or to the health system. Some of these barriers, particularly those related to the distillation, dissemination and packaging of research evidence, could be overcome by recent and ongoing developments in portable/wearable computers, internet appliances, multimedia and wireless broadband internet traffic. This article describes specific EBDM-related tools, with emphasis on internet-enabled "how to" books; and tools to improve the quality of reporting research, to formulate questions; to search for evidence; to access journals, systematic reviews and guidelines; to interact with organizations promoting EBDM; and to tailor evidence to individual cases. However, thinking that all barriers to the practice of EBDM could be solved by fancy information technology is naïve. Barriers related to the generation, interpretation, integration and use of the evidence demand more complex and perhaps unfeasible solutions, as overcoming them will require substantial changes in the structure of the health system, in the politics of science and in the way in which humans think and behave.

Short-term Variability of Extinction by Broadband Stellar Photometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musat, I.C.; Ellingson, R.G.

2005-03-18

Aerosol optical depth variation over short-term time intervals is determined from broadband observations of stars with a whole sky imager. The main difficulty in such measurements consists of accurately separating the star flux value from the non-stellar diffuse skylight. Using correction method to overcome this difficulty, the monochromatic extinction at the ground due to aerosols is extracted from heterochromatic measurements. A form of closure is achieved by comparison with simultaneous or temporally close measurements with other instruments, and the total error of the method, as a combination of random error of measurements and systematic error of calibration and model, ismore » assessed as being between 2.6 and 3% rms.« less

Mechanism of conductivity relaxation in liquid and polymeric electrolytes: Direct link between conductivity and diffusivity

DOE PAGES

Gainaru, Catalin P.; Technische Univ. Dortmund, Dortmund; Stacy, Eric W.; ...

2016-09-28

Combining broadband impedance spectroscopy, differential scanning calorimetry, and nuclear magnetic resonance we analyzed charge and mass transport in two polymerized ionic liquids and one of their monomeric precursors. In order to establish a general procedure for extracting single-particle diffusivity from their conductivity spectra, we critically assessed several approaches previously employed to describe the onset of diffusive charge dynamics and of the electrode polarization in ion conducting materials. Based on the analysis of the permittivity spectra, we demonstrate that the conductivity relaxation process provides information on ion diffusion and the magnitude of cross-correlation effects between ionic motions. A new approach ismore » introduced which is able to estimate ionic diffusivities from the characteristic times of conductivity relaxation and ion concentration without any adjustable parameters. Furthermore, this opens the venue for a deeper understanding of charge transport in concentrated and diluted electrolyte solutions.« less

Progress towards broadband Raman quantum memory in Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Saglamyurek, Erhan; Hrushevskyi, Taras; Smith, Benjamin; Leblanc, Lindsay

2017-04-01

Optical quantum memories are building blocks for quantum information technologies. Efficient and long-lived storage in combination with high-speed (broadband) operation are key features required for practical applications. While the realization has been a great challenge, Raman memory in Bose-Einstein condensates (BECs) is a promising approach, due to negligible decoherence from diffusion and collisions that leads to seconds-scale memory times, high efficiency due to large atomic density, the possibility for atom-chip integration with micro photonics, and the suitability of the far off-resonant Raman approach with storage of broadband photons (over GHz) [5]. Here we report our progress towards Raman memory in a BEC. We describe our apparatus recently built for producing BEC with 87Rb atoms, and present the observation of nearly pure BEC with 5x105 atoms at 40 nK. After showing our initial characterizations, we discuss the suitability of our system for Raman-based light storage in our BEC.

Broadband light trapping in nanotextured thin film photovoltaic devices

NASA Astrophysics Data System (ADS)

Mennucci, Carlo; Muhammad, M. H.; Hameed, Mohamed Farhat O.; Mohamed, Shaimaa A.; Abdelkhalik, Mohamed S.; Obayya, S. S. A.; Buatier de Mongeot, Francesco

2018-07-01

Substrates with engineered roughness are studied with the aim of achieving broadband and omnidirectional photon harvesting in thin film devices. Light coupling across the interfaces of a photonic device is induced by uniaxial pseudo-periodic gratings formed in a self-organised fashion via de-focused ion beam sputtering (IBS). The optical properties of the textured interfaces are assessed both experimentally and numerically using finite difference time domain (FDTD) algorithm, quantitatively demonstrating the optimal geometries which favour broadband diffuse scattering of radiation across the Vis-NIR spectral range. Thin film amorphous silicon solar cells based on the nanostructured patterns have been numerically studied via FDTD to assess absorption enhancement in comparison to flat reference devices, finding a 25% increase of short-circuit current, in good agreement with the experiment. Similar light trapping experiments performed on prototypical solar cells employing a PTB7:PC61BM organic absorber, allow to extend the general validity of the results to a relevant class of materials in the view of photovoltaic applications.

Broadband Internet Based Service to Passengers and Crew On-board Aircraft

NASA Astrophysics Data System (ADS)

Azzarelli, Tony

2003-07-01

The Connexion by BoeingSM (CbB) global network will provide broadband information services to aircraft passengers and crews. Through this Ku-band (14 GHz (uplink) and 11/12 GHz (downlink)) satellite-based system, aircraft passengers and crew will no longer be limited to pre-packaged services, but instead will be able to access the full range of broadband services from their seats using their laptop, PDA or the on-board IFE console.The kind of services offered to passengers are based on the internet/intranet access via their own laptops and PDA (using Ethernet wired cable, or wireless 802.11b access), while those offered to the crew can range between various crew application (such as weather updates and travel information) and aircraft health monitoring.The CbB system is divided into four basic layers of infrastructure:(1) an airborne segment, i.e. the Aircraft Earth Station (AES) consisting of proprietary high gain antenna, transceivers and other on-board subsystems providing a nominal return link data rate of 1 Mbps and a forward link data rates up to 20 Mbps;(2) a space segment consisting of leased satellite transponders on existing in-orbit Geostationary satellites;(3) a ground segment consisting of one or more leased satellite land earth stations (LESs) and redundant interconnection facilities; and;(4) a network operations centre (NOC) segment.During 2003, trials with Lufthansa (DLH) and British Airways (BA) have proved very successful. This has resulted in the recent signing of an agreement with Lufthansa which calls for the Connexion by BoeingSM service to be installed on Lufthansa's fleet of approximately 80 long-haul aircraft, including Boeing 747-400 and Airbus A330 and A340 aircraft, beginning in early 2004. BA is expected to follow soon. In addition to the successful recent service demonstrations, both Japan Airlines (JAL) and Scandinavian Airlines System (SAS) have announced their intent to install the revolutionary service on their long-range aircraft.

Diffusion of the Internet within a Graduate School.

ERIC Educational Resources Information Center

Sherry, Lorraine

This paper reports the results of a five-year case study of the use of online tools: Internet, e-mail, and the World Wide Web, within a Graduate School of Education. The conceptual framework was independently developed, but because of the striking parallel with activity theory, activity theory became the overall framework for interpreting…

Global Market Access in the Internet Era: South Africa's Wood Furniture Industry.

ERIC Educational Resources Information Center

Moodley, Sagren

2002-01-01

Explores the link between Internet connectivity and access to global markets, and uses the South African wood furniture producers as they are integrated into global value chains and exposed to the demands of more sophisticated markets. Articulates policy recommendations to promote greater diffusion of e-commerce technologies in the wood furniture…

The Association of Patient Factors, Digital Access, and Online Behavior on Sustained Patient Portal Use: A Prospective Cohort of Enrolled Users

PubMed Central

Nazi, Kim M; Hibbard, Judith H; Houston, Thomas K

2017-01-01

Background As electronic health records and computerized workflows expand, there are unprecedented opportunities to digitally connect with patients using secure portals. To realize the value of patient portals, initial reach across populations will need to be demonstrated, as well as sustained usage over time. Objective The study aim was to identify patient factors associated with short-term and long-term portal usage after patients registered to access all portal functions. Methods We prospectively followed a cohort of patients at a large Department of Veterans Affairs (VA) health care facility who recently completed identity proofing to use the VA patient portal. Information collected at baseline encompassed patient factors potentially associated with portal usage, including: demographics, Internet access and use, health literacy, patient activation, and self-reported health conditions. The primary outcome was the frequency of portal log-ins during 6-month and 18-month time intervals after study enrollment. Results A total of 270 study participants were followed prospectively. Almost all participants (260/268, 97.0%) reported going online, typically at home (248/268, 92.5%). At 6 months, 84.1% (227/270) of participants had visited the portal, with some variation in usage across demographic and health-related subgroups. There were no significant differences in portal log-ins by age, gender, education, marital status, race/ethnicity, distance to a VA facility, or patient activation measure. Significantly higher portal usage was seen among participants using high-speed broadband at home, greater self-reported ability using the Internet, and routinely going online. By 18 months, 91% participants had logged in to the portal, and no significant associations were found between usage and demographics, health status, or patient activation. When examining portal activity between 6 and 18 months, patients who were infrequent or high portal users remained in those categories, respectively. Conclusions Short-term and long-term portal usage was associated with having broadband at home, high self-rated ability when using the Internet, and overall online behavior. Digital inclusion, or ready access to the Internet and digital skills, appears to be a social determinant in patient exposure to portal services. PMID:29042345

The Internet as a research site: establishment of a web-based longitudinal study of the nursing and midwifery workforce in three countries.

PubMed

Huntington, Annette; Gilmour, Jean; Schluter, Philip; Tuckett, Anthony; Bogossian, Fiona; Turner, Catherine

2009-06-01

The aim of this paper is to describe the development of a web-based longitudinal research project, The Nurses and Midwives e-cohort Study. The Internet has only recently been used for health research. However, web-based methodologies are increasingly discussed as significant and inevitable developments in research as Internet access and use rapidly increases worldwide. In 2006, a longitudinal web-based study of nurses and midwives workforce participation patterns, health and wellbeing, and lifestyle choices was established. Participating countries are Australia, New Zealand and the United Kingdom. Data collection is handled through a dedicated website using a range of standardized tools combined into one comprehensive questionnaire. Internet-specific data collection and a range of recruitment and retention strategies have been developed for this study. Internet-based technology can support the maintenance of cohorts across multiple countries and jurisdictions to explore factors influencing workforce participation. However, barriers to widespread adoption of web-based approaches include website development costs, the need for fast broadband connection for large data collection instruments, and varying degrees of Internet and computer literacy in the nursing and midwifery workforce. Many of the issues reported in this paper are transitional in nature at a time of rapid technological development. The development of on-line methods and tools is a major and exciting development in the world of research. Research via the world-wide web can support international collaborations across borders and cultures.

Smartphones in the Tactical Environment: A Framework for Financial Analysis of U.S. Marine Corps Options

DTIC Science & Technology

2013-09-30

growth contribution equal to 0.44% annually, while the last in the list Nepal has growth returns from mobiles of around 0.12% annually...www.brookings.edu/research/papers/2012/05/22-mobile-health-west List of countries by number of broadband Internet subscriptions. (2013). Wikipedia. Retrieved...valid OMB control number . 1. REPORT DATE 30 SEP 2013 2. REPORT TYPE 3. DATES COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE

Introduction to the world wide web.

PubMed

Downes, P K

2007-05-12

The World Wide Web used to be nicknamed the 'World Wide Wait'. Now, thanks to high speed broadband connections, browsing the web has become a much more enjoyable and productive activity. Computers need to know where web pages are stored on the Internet, in just the same way as we need to know where someone lives in order to post them a letter. This section explains how the World Wide Web works and how web pages can be viewed using a web browser.

An Analysis of How Education, Age, Overseas Assignments, and Mavenism Impact Use of New Media Technology

DTIC Science & Technology

2010-12-01

The Journal of Consumer Marketing, Vol. 12, Iss 3, 4 -22. Yang, D. (2007) What Happens If Facebook Thinks You’re Not Real? Retrieved on January 10...48 Appendix C – Instrument 3 -List of Semi-Structured Interview questions .......................49 Appendix D – Instrument 4 - Instructions for...Internet users have watched a 4 video online. This same report showed that 85% of young broadband users have watched an online video, and 62

Reach the Unreached -IIRS Outreach program for enhanced learning to all

NASA Astrophysics Data System (ADS)

Krishna Murthy, Y. V. N.; Raju, P. L. N.; Srivastav, S. K.; Karnatak, H.; Gupta, P. Kumar; Mahadevaswamy, M.; Viswakarma, J.

2014-11-01

With the advent of Information and Communication Technology and improved broadband internet connectivity has enhanced the scope of learning any time anywhere, going beyond the traditional classroom approach. To support distance learning, Indian Space Research Organisation, Government of India has launched dedicated communication satellite called EDUSAT in 2004. The satellite is widely used for variety of applications like Tele-education, Tele-medicine, Village Resource Centres, mobile satellite services, disaster management support and television broadcasting educating farmers for agriculture and other purposes. One of the prime applications of EDUSAT satellite is tele-education at various levels (i.e. school level/UG /PG level) by different ministries / autonomous organizations / departments/institutions/universities in India effectively utilized the EDUSAT for Tele-education. The initial focus of IIRS was to use EDUSAT/INSAT 4CR satellite for distance learning but extended the scope to use broadband internet so that access to large number of institutions/universities /individuals with little cost the User. IIRS distance learning program initiated in 2007 and successfully conducted 12 programs in the last eight years. The first course was attended from twelve universities and the number of institutions /universities increased manifold. The thirteenth course is progress with more than 210 institutions /universities /departments /individuals with more than 3200 number of participants attending the program live and interactive. IIRS program is unique and interactive and demand is increasing not only universities but among research institutions, user departments and individuals.

White matter connectivity and Internet gaming disorder

PubMed Central

Jeong, Bum Seok; Han, Doug Hyun; Kim, Sun Mi; Lee, Sang Won; Renshaw, Perry F.

2017-01-01

Internet use and on-line game play stimulate corticostriatal-limbic circuitry in both healthy subjects and subjects with Internet gaming disorder (IGD). We hypothesized that increased fractional anisotropy (FA) with decreased radial diffusivity (RD) would be observed in IGD subjects, compared with healthy control subjects, and that these white matter indices would be associated with clinical variables including duration of illness and executive function. We screened 181 male patients in order to recruit a large number (n = 58) of IGD subjects without psychiatric co-morbidity as well as 26 male healthy comparison subjects. Multiple diffusion-weighted images were acquired using a 3.0 Tesla magnetic resonance imaging scanner. Tract-based spatial statistics was applied to compare group differences in diffusion tensor imaging (DTI) metrics between IGD and healthy comparison subjects. IGD subjects had increased FA values within forceps minor, right anterior thalamic radiation, right corticospinal tract, right inferior longitudinal fasciculus, right cingulum to hippocampus and right inferior fronto-occipital fasciculus (IFOF) as well as parallel decreases in RD value within forceps minor, right anterior thalamic radiation and IFOF relative to healthy control subjects. In addition, the duration of illness in IGD subjects was positively correlated with the FA values (integrity of white matter fibers) and negatively correlated with RD scores (diffusivity of axonal density) of whole brain white matter. In IGD subjects without psychiatric co-morbidity, our DTI results suggest that increased myelination (increased FA and decreased RD values) in right-sided frontal fiber tracts may be the result of extended game play. PMID:25899390

Ngi and Internet2: accelerating the creation of tomorrow's internet.

PubMed

Kratz, M; Ackerman, M; Hanss, T; Corbato, S

2001-01-01

Internet2 is a consortium of leading U.S. universities working in partnership with industry and the U.S. government's Next Generation Internet (NGI) initiative to develop a faster, more reliable Internet for research and education including enhanced, high-performance networking services and the advanced applications that are enabled by those services [1]. By facilitating and coordinating the development, deployment, operation, and technology transfer of advanced, network-based applications and network services, Internet2 and NGI are working together to fundamentally change the way scientists, engineers, clinicians, and others work together. [http://www.internet2.edu] The NGI Program has three tracks: research, network testbeds, and applications. The aim of the research track is to promote experimentation with the next generation of network technologies. The network testbed track aims to develop next generation network testbeds to connect universities and federal research institutions at speeds that are sufficient to demonstrate new technologies and support future research. The aim of the applications track is to demonstrate new applications, enabled by the NGI networks, to meet important national goals and missions [2]. [http://www.ngi.gov/] The Internet2/NGI backbone networks, Abilene and vBNS (very high performance Backbone Network Service), provide the basis of collaboration and development for a new breed of advanced medical applications. Academic medical centers leverage the resources available throughout the Internet2 high-performance networking community for high-capacity broadband and selectable quality of service to make effective use of national repositories. The Internet2 Health Sciences Initiative enables a new generation of emerging medical applications whose architecture and development have been restricted by or are beyond the constraints of traditional Internet environments. These initiatives facilitate a variety of activities to foster the development and deployment of emerging applications that meet the requirements of clinical practice, medical and related biological research, education, and medical awareness throughout the public sector. Medical applications that work with high performance networks and supercomputing capabilities offer exciting new solutions for the medical industry. Internet2 and NGI,strive to combine the expertise of their constituents to establish a distributed knowledge system for achieving innovation in research, teaching, learning, and clinical care.

Observation of High-Frequency Electrostatic Waves in the Vicinity of the Reconnection Ion Diffusion Region by the Spacecraft of the Magnetospheric Multiscale (MMS) Mission

NASA Technical Reports Server (NTRS)

Zhou, M.; Ashour-Abdalla, M.; Berchem, J.; Walker, R. J.; Liang, H.; El-Alaoui, M.; Goldstein, M. L.; Lindqvist, P.-A.; Marklund, G.; Khotyaintsev, Y. V.;

Adoption and Use of Internet Technologies in Health Communication: Examining Disparities in Diffusion Patterns, Health Information Sources, and Patient-Provider Encounters

ERIC Educational Resources Information Center

Massey, Philip Minter

2013-01-01

This dissertation examines the impact of internet technologies on the field of health communication. Access and use of health communication technologies has and will continue to become increasingly important to manage and treat chronic conditions and other ailments, particularly in the context of health care reform that promotes improved quality…

Factors Influencing the Adoption of the Internet as a Teaching Tool at Foreign Language Schools

ERIC Educational Resources Information Center

Martins, Claudia B. M. J.; Steil, Andrea V.; Todesco, Jose L.

2004-01-01

The present article describes a research that determined the factors influencing language schools in Brazil to adopt the Internet as a teaching tool. The theoretical framework used was Rogers, E. (1995). "Diffusion of innovation" (4th ed.). New York: The Free Press. theory of perceived attributes. A survey was carried out with 92…

Personal Data Protection in E-Government: Globalization or Glocalization? A Comparative Study of the United States, Germany and China

ERIC Educational Resources Information Center

Wu, Yuehua

2010-01-01

The development and diffusion of information and communication technologies, particularly the internet, creates a worldwide trend of using ICTs and the internet to deliver public services. This new form of electronic administration--e-government--potentially offers great benefits to society in that it can enhance public service efficiency,…

Fluorescence spectroscopy for endogenous porphyrins in human facial skin

NASA Astrophysics Data System (ADS)

Seo, I.; Tseng, S. H.; Cula, G. O.; Bargo, P. R.; Kollias, N.

2009-02-01

The activity of certain bacteria in skin is known to correlate to the presence of porphyrins. In particular the presence of coproporphyrin produced by P.acnes inside plugged pores has been correlated to acne vulgaris. Another porphyrin encountered in skin is protoporphyrin IX, which is produced by the body in the pathway for production of heme. In the present work, a fluorescence spectroscopy system was developed to measure the characteristic spectrum and quantify the two types of porphyrins commonly present in human facial skin. The system is comprised of a Xe lamp both for fluorescence excitation and broadband light source for diffuse reflectance measurements. A computer-controlled filter wheel enables acquisition of sequential spectra, first excited by blue light at 405 nm then followed by the broadband light source, at the same location. The diffuse reflectance spectrum was used to correct the fluorescence spectrum due to the presence of skin chromophores, such as blood and melanin. The resulting fluorescence spectra were employed for the quantification of porphyrin concentration in a population of healthy subjects. The results show great variability on the concentration of these porphyrins and further studies are being conducted to correlate them with skin conditions such as inflammation and acne vulgaris.

Solution processable broadband transparent mixed metal oxide nanofilm optical coatings via substrate diffusion doping.

PubMed

Glynn, Colm; Aureau, Damien; Collins, Gillian; O'Hanlon, Sally; Etcheberry, Arnaud; O'Dwyer, Colm

2015-12-21

Devices composed of transparent materials, particularly those utilizing metal oxides, are of significant interest due to increased demand from industry for higher fidelity transparent thin film transistors, photovoltaics and a myriad of other optoelectronic devices and optics that require more cost-effective and simplified processing techniques for functional oxides and coatings. Here, we report a facile solution processed technique for the formation of a transparent thin film through an inter-diffusion process involving substrate dopant species at a range of low annealing temperatures compatible with processing conditions required by many state-of-the-art devices. The inter-diffusion process facilitates the movement of Si, Na and O species from the substrate into the as-deposited vanadium oxide thin film forming a composite fully transparent V0.0352O0.547Si0.4078Na0.01. Thin film X-ray diffraction and Raman scattering spectroscopy show the crystalline component of the structure to be α-NaVO3 within a glassy matrix. This optical coating exhibits high broadband transparency, exceeding 90-97% absolute transmission across the UV-to-NIR spectral range, while having low roughness and free of surface defects and pinholes. The production of transparent films for advanced optoelectronic devices, optical coatings, and low- or high-k oxides is important for planar or complex shaped optics or surfaces. It provides opportunities for doping metal oxides to ternary, quaternary or other mixed metal oxides on glass, encapsulants or other substrates that facilitate diffusional movement of dopant species.

Establishment of a broadband radiometric ground station on the South African east coast

NASA Astrophysics Data System (ADS)

Brooks, Michael J.; Roberts, Lance W.

2009-08-01

A radiometric monitoring program for solar irradiance has been initiated on the Howard College campus of the University of KwaZulu-Natal (UKZN) in Durban, South Africa. This paper describes the establishment of the broadband ground station which employs conventional radiometers and a new type of pyranometer shadow band. The ZEBRA (Zonal Exposure to Broadband RAdiation) band consists of a perforated metal strip that permits the separation of direct normal and diffuse irradiance from global data with a single pyranometer. In this paper a time-based model of the new band's shading mask is described. The model is derived from a ray tracing exercise that accounts for ZEBRA geometry and solar position throughout a generic 365-day year. The UKZN facility lies at 29.9° South latitude and is part of a larger test initiative for the new shadow band that includes the NREL Solar Radiation Research Laboratory in Colorado. Data from northern and southern hemisphere test sites are to be used to characterize performance of the band under a range of conditions and for comparison with output from the newly developed model.

Analysis and application of intelligence network based on FTTH

NASA Astrophysics Data System (ADS)

Feng, Xiancheng; Yun, Xiang

2008-12-01

With the continued rapid growth of Internet, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. The bandwidth requirement increase continuously. Network technique, optical device technical development is swift and violent. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. Firstly, it introduces the main service which FTTH supports, main analysis key technology such as FTTH system composition way, topological structure, multiplexing, optical cable and device. It focus two kinds of realization methods - PON, P2P technology. Then it proposed that the solution of FTTH can support comprehensive access (service such as broadband data, voice, video and narrowband private line). Finally, it shows the engineering application for FTTH in the district and building. It brings enormous economic benefits and social benefit.

Telebation: next-generation telemedicine in remote airway management using current wireless technologies.

PubMed

Mosier, Jarrod; Joseph, Bellal; Sakles, John C

2013-02-01

Since the first remote intubation with telemedicine guidance, wireless technology has advanced to enable more portable methods of telemedicine involvement in remote airway management. Three voice over Internet protocol (VoIP) services were evaluated for quality of image transmitted, data lag, and audio quality with remotely observed and assisted intubations in an academic emergency department. The VoIP clients evaluated were Apple (Cupertino, CA) FaceTime(®), Skype™ (a division of Microsoft, Luxembourg City, Luxembourg), and Tango(®) (TangoMe, Palo Alto, CA). Each client was tested over a Wi-Fi network as well as cellular third generation (3G) (Skype and Tango). All three VoIP clients provided acceptable image and audio quality. There is a significant data lag in image transmission and quality when VoIP clients are used over cellular broadband (3G) compared with Wi-Fi. Portable remote telemedicine guidance is possible with newer technology devices such as a smartphone or tablet, as well as VoIP clients used over Wi-Fi or cellular broadband.

Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services

NASA Technical Reports Server (NTRS)

Durresi, Arjan; Kota, Sastri; Goyal, Mukul; Jain, Raj; Bharani, Venkata

2001-01-01

Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.

Stochastic Packet Loss Model to Evaluate QoE Impairments

NASA Astrophysics Data System (ADS)

Hohlfeld, Oliver

With provisioning of broadband access for mass market—even in wireless and mobile networks—multimedia content, especially real-time streaming of high-quality audio and video, is extensively viewed and exchanged over the Internet. Quality of Experience (QoE) aspects, describing the service quality perceived by the user, is a vital factor in ensuring customer satisfaction in today's communication networks. Frameworks for accessing quality degradations in streamed video currently are investigated as a complex multi-layered research topic, involving network traffic load, codec functions and measures of user perception of video quality.

Media, Multimedia, Omnimedia: Selected Papers from the CETaLL Symposium on the Occasion of the AILA World Congress (11th, Jyvaskyla, Finland, August 4-9, 1996) and Man and Media Symposium (5th, Nancy, France, June 5-7, 1997). Bayreuth Contributions to Glottodidactics, Vol. 7.

ERIC Educational Resources Information Center

Hogan-Brun, Gabrielle, Ed.; Jung, Udo O. H., Ed.

This volume presents a collection of 14 selected papers on the theme of how to use media technology to enhance language learning and teaching. Papers explore innovative ways to use existing technologies in broadband networks, the telemedia, and multimedia, while others focus on the use of the Internet. It is hoped that exploring the use of these…

Applications and Implications of Fractional Dynamics for Dielectric Relaxation

NASA Astrophysics Data System (ADS)

Hilfer, R.

This article summarizes briefly the presentation given by the author at the NATO Advanced Research Workshop on "Broadband Dielectric Spectroscopy and its Advanced Technological Applications", held in Perpignan, France, in September 2011. The purpose of the invited presentation at the workshop was to review and summarize the basic theory of fractional dynamics (Hilfer, Phys Rev E 48:2466, 1993; Hilfer and Anton, Phys Rev E Rapid Commun 51:R848, 1995; Hilfer, Fractals 3(1):211, 1995; Hilfer, Chaos Solitons Fractals 5:1475, 1995; Hilfer, Fractals 3:549, 1995; Hilfer, Physica A 221:89, 1995; Hilfer, On fractional diffusion and its relation with continuous time random walks. In: Pekalski et al. (eds) Anomalous diffusion: from basis to applications. Springer, Berlin, p 77, 1999; Hilfer, Fractional evolution equations and irreversibility. In: Helbing et al. (eds) Traffic and granular flow'99. Springer, Berlin, p 215, 2000; Hilfer, Fractional time evolution. In: Hilfer (ed) Applications of fractional calculus in physics. World Scientific, Singapore, p 87, 2000; Hilfer, Remarks on fractional time. In: Castell and Ischebeck (eds) Time, quantum and information. Springer, Berlin, p 235, 2003; Hilfer, Physica A 329:35, 2003; Hilfer, Threefold introduction to fractional derivatives. In: Klages et al. (eds) Anomalous transport: foundations and applications. Wiley-VCH, Weinheim, pp 17-74, 2008; Hilfer, Foundations of fractional dynamics: a short account. In: Klafter et al. (eds) Fractional dynamics: recent advances. World Scientific, Singapore, p 207, 2011) and demonstrate its relevance and application to broadband dielectric spectroscopy (Hilfer, J Phys Condens Matter 14:2297, 2002; Hilfer, Chem Phys 284:399, 2002; Hilfer, Fractals 11:251, 2003; Hilfer et al., Fractional Calc Appl Anal 12:299, 2009). It was argued, that broadband dielectric spectroscopy might be useful to test effective field theories based on fractional dynamics.

The improved broadband Real-Time Seismic Network in Romania

NASA Astrophysics Data System (ADS)

Neagoe, C.; Ionescu, C.

2009-04-01

Starting with 2002 the National Institute for Earth Physics (NIEP) has developed its real-time digital seismic network. This network consists of 96 seismic stations of which 48 broad band and short period stations and two seismic arrays are transmitted in real-time. The real time seismic stations are equipped with Quanterra Q330 and K2 digitizers, broadband seismometers (STS2, CMG40T, CMG 3ESP, CMG3T) and strong motions sensors Kinemetrics episensors (+/- 2g). SeedLink and AntelopeTM (installed on MARMOT) program packages are used for real-time (RT) data acquisition and exchange. The communication from digital seismic stations to the National Data Center in Bucharest is assured by 5 providers (GPRS, VPN, satellite communication, radio lease line and internet), which will assure the back-up communications lines. The processing centre runs BRTT's AntelopeTM 4.10 data acquisition and processing software on 2 workstations for real-time processing and post processing. The Antelope Real-Time System is also providing automatic event detection, arrival picking, event location and magnitude calculation. It provides graphical display and reporting within near-real-time after a local or regional event occurred. Also at the data center was implemented a system to collect macroseismic information using the internet on which macro seismic intensity maps are generated. In the near future at the data center will be install Seiscomp 3 data acquisition processing software on a workstation. The software will run in parallel with Antelope software as a back-up. The present network will be expanded in the near future. In the first half of 2009 NIEP will install 8 additional broad band stations in Romanian territory, which also will be transmitted to the data center in real time. The Romanian Seismic Network is permanently exchanging real -time waveform data with IRIS, ORFEUS and different European countries through internet. In Romania, magnitude and location of an earthquake are now available within a few minutes after the earthquake occurred. One of the greatest challenges in the near future is to provide shaking intensity maps and other ground motion parameters, within 5 minutes post-event, on the Internet and GIS-based format in order to improve emergency response, public information, preparedness and hazard mitigation

Control of Silver Diffusion in Low-Temperature Co-Fired Diopside Glass-Ceramic Microwave Dielectrics

PubMed Central

Chou, Chen-Chia; Chang, Chun-Yao; Chen, Guang-Yu; Feng, Kuei-Chih; Tsao, Chung-Ya

2017-01-01

Electrode material for low-temperature co-fired diopside glass-ceramic used for microwave dielectrics was investigated in the present work. Diffusion of silver from the electrode to diopside glass-ceramics degrades the performance of the microwave dielectrics. Two approaches were adopted to resolve the problem of silver diffusion. Firstly, silicon-oxide (SiO2) powder was employed and secondly crystalline phases were chosen to modify the sintering behavior and inhibit silver ions diffusion. Nanoscale amorphous SiO2 powder turns to the quartz phase uniformly in dielectric material during the sintering process, and prevents the silver from diffusion. The chosen crystalline phase mixing into the glass-ceramics enhances crystallinity of the material and inhibits silver diffusion as well. The result provides a method to decrease the diffusivity of silver ions by adding the appropriate amount of SiO2 and appropriate crystalline ceramics in diopside glass-ceramic dielectric materials. Finally, we used IEEE 802.11a 5.8 GHz as target specification to manufacture LTCC antenna and the results show that a good broadband antenna was made using CaMgSi2O6 with 4 wt % silicon oxide. PMID:29286330

Simulation of Cosmic Ray Acceleration, Propagation and Interaction in SNR Environment

NASA Astrophysics Data System (ADS)

Lee, S. H.; Kamae, T.; Ellison, D. C.

2007-07-01

Recent studies of young supernova remnants (SNRs) with Chandra, XMM, Suzaku and HESS have revealed complex morphologies and spectral features of the emission sites. The critical question of the relative importance of the two competing gamma-ray emission mechanisms in SNRs; inverse-Compton scattering by high-energy electrons and pion production by energetic protons, may be resolved by GLAST-LAT. To keep pace with the improved observations, we are developing a 3D model of particle acceleration, diffusion, and interaction in a SNR where broad-band emission from radio to multi-TeV energies, produced by shock accelerated electrons and ions, can be simulated for a given topology of shock fronts, magnetic field, and ISM densities. The 3D model takes as input, the particle spectra predicted by a hydrodynamic simulation of SNR evolution where nonlinear diffusive shock acceleration is coupled to the remnant dynamics (e.g., Ellison, Decourchelle & Ballet; Ellison & Cassam-Chenai Ellison, Berezhko & Baring). We will present preliminary models of the Galactic Ridge SNR RX J1713-3946 for selected choices of SNR parameters, magnetic field topology, and ISM density distributions. When constrained by broad-band observations, our models should predict the extent of coupling between spectral shape and morphology and provide direct information on the acceleration efficiency of cosmic-ray electrons and ions in SNRs.

Calibration procedure of Hukseflux SR25 to Establish the Diffuse Reference for the Outdoor Broadband Radiometer Calibration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reda, Ibrahim M.; Andreas, Afshin M.

2017-08-01

Accurate pyranometer calibrations, traceable to internationally recognized standards, are critical for solar irradiance measurements. One calibration method is the component summation method, where the pyranometers are calibrated outdoors under clear sky conditions, and the reference global solar irradiance is calculated as the sum of two reference components, the diffuse horizontal and subtended beam solar irradiances. The beam component is measured with pyrheliometers traceable to the World Radiometric Reference, while there is no internationally recognized reference for the diffuse component. In the absence of such a reference, we present a method to consistently calibrate pyranometers for measuring the diffuse component. Themore » method is based on using a modified shade/unshade method and a pyranometer with less than 0.5 W/m2 thermal offset. The calibration result shows that the responsivity of Hukseflux SR25 pyranometer equals 10.98 uV/(W/m2) with +/-0.86 percent uncertainty.« less

The role of Internet resources in clinical oncology: promises and challenges.

PubMed

Hesse, Bradford W; Greenberg, Alexandra J; Rutten, Lila J Finney

2016-12-01

The Internet is a valuable tool that continues to revolutionize many aspects of our lives; however, the ability to disseminate diverse data across populations and nations presents both opportunities and challenges. Online resources are increasingly used in health care, providing wider access to information for patients, researchers, and clinicians. At the turn of the millennium, the National Cancer Institute (NCI) predicted that Internet-based technologies would create a revolution in communication for oncology professionals and patients with cancer. Herein, findings from the NCI's Health Information National Trends Survey are reviewed to give insight into how Internet trends related to oncology patients are evolving. Future trends are discussed, including examples of 'connected health' in oncology; the spread of mobile and ubiquitous access points to Internet-hosted information; the diffusion of devices, sensors, and apps; the spread of personal data sharing; and an evolution in how networks can support person-centred and family-centred care.

Totally Connected Healthcare with TV White Spaces.

PubMed

Katzis, Konstantinos; Jones, Richard W; Despotou, Georgios

2017-01-01

Recent technological advances in electronics, wireless communications and low cost medical sensors generated a plethora of Wearable Medical Devices (WMDs), which are capable of generating considerably large amounts of new, unstructured real-time data. This contribution outlines how this data can be propagated to a healthcare system through the internet, using long distance Radio Access Networks (RANs) and proposes a novel communication system architecture employing White Space Devices (WSD) to provide seamless connectivity to its users. Initial findings indicate that the proposed communication system can facilitate broadband services over a large geographical area taking advantage of the freely available TV White Spaces (TVWS).

Broadband light sources based on InAs/InGaAs metamorphic quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seravalli, L.; Trevisi, G.; Frigeri, P.

We propose a design for a semiconductor structure emitting broadband light in the infrared, based on InAs quantum dots (QDs) embedded into a metamorphic step-graded In{sub x}Ga{sub 1−x}As buffer. We developed a model to calculate the metamorphic QD energy levels based on the realistic QD parameters and on the strain-dependent material properties; we validated the results of simulations by comparison with the experimental values. On this basis, we designed a p-i-n heterostructure with a graded index profile toward the realization of an electrically pumped guided wave device. This has been done by adding layers where QDs are embedded in In{submore » x}Al{sub y}Ga{sub 1−x−y}As layers, to obtain a symmetric structure from a band profile point of view. To assess the room temperature electro-luminescence emission spectrum under realistic electrical injection conditions, we performed device-level simulations based on a coupled drift-diffusion and QD rate equation model. On the basis of the device simulation results, we conclude that the present proposal is a viable option to realize broadband light-emitting devices.« less

Ground motion simulations in Marmara (Turkey) region from 3D finite difference method

NASA Astrophysics Data System (ADS)

Aochi, Hideo; Ulrich, Thomas; Douglas, John

2016-04-01

In the framework of the European project MARSite (2012-2016), one of the main contributions from our research team was to provide ground-motion simulations for the Marmara region from various earthquake source scenarios. We adopted a 3D finite difference code, taking into account the 3D structure around the Sea of Marmara (including the bathymetry) and the sea layer. We simulated two moderate earthquakes (about Mw4.5) and found that the 3D structure improves significantly the waveforms compared to the 1D layer model. Simulations were carried out for different earthquakes (moderate point sources and large finite sources) in order to provide shake maps (Aochi and Ulrich, BSSA, 2015), to study the variability of ground-motion parameters (Douglas & Aochi, BSSA, 2016) as well as to provide synthetic seismograms for the blind inversion tests (Diao et al., GJI, 2016). The results are also planned to be integrated in broadband ground-motion simulations, tsunamis generation and simulations of triggered landslides (in progress by different partners). The simulations are freely shared among the partners via the internet and the visualization of the results is diffused on the project's homepage. All these simulations should be seen as a reference for this region, as they are based on the latest knowledge that obtained during the MARSite project, although their refinement and validation of the model parameters and the simulations are a continuing research task relying on continuing observations. The numerical code used, the models and the simulations are available on demand.

Staging on the Internet: research on online photo album users in Taiwan with the spectacle/performance paradigm.

PubMed

Hsu, Chiung-wen

2007-08-01

This study explores motivations of online photo album users in Taiwan and the distinctive "staging" phenomenon with media gratifications and an a priori theoretical framework, the spectacle/performance paradigm (SPP). Media drenching, performance, function and reference are "new" gratifications, which no prior research was found. These gratifications are consistent with the argument of the "diffused audience" on the Internet. This study verifies that the process-content distinction may not be applicable in the Internet setting because distinctions between the real world and the mediated world are vanishing, which is also the main argument of the SPP paradigm.

Discrete and broadband electron acceleration in Jupiter's powerful aurora.

PubMed

Mauk, B H; Haggerty, D K; Paranicas, C; Clark, G; Kollmann, P; Rymer, A M; Bolton, S J; Levin, S M; Adriani, A; Allegrini, F; Bagenal, F; Bonfond, B; Connerney, J E P; Gladstone, G R; Kurth, W S; McComas, D J; Valek, P

2017-09-06

The most intense auroral emissions from Earth's polar regions, called discrete for their sharply defined spatial configurations, are generated by a process involving coherent acceleration of electrons by slowly evolving, powerful electric fields directed along the magnetic field lines that connect Earth's space environment to its polar regions. In contrast, Earth's less intense auroras are generally caused by wave scattering of magnetically trapped populations of hot electrons (in the case of diffuse aurora) or by the turbulent or stochastic downward acceleration of electrons along magnetic field lines by waves during transitory periods (in the case of broadband or Alfvénic aurora). Jupiter's relatively steady main aurora has a power density that is so much larger than Earth's that it has been taken for granted that it must be generated primarily by the discrete auroral process. However, preliminary in situ measurements of Jupiter's auroral regions yielded no evidence of such a process. Here we report observations of distinct, high-energy, downward, discrete electron acceleration in Jupiter's auroral polar regions. We also infer upward magnetic-field-aligned electric potentials of up to 400 kiloelectronvolts, an order of magnitude larger than the largest potentials observed at Earth. Despite the magnitude of these upward electric potentials and the expectations from observations at Earth, the downward energy flux from discrete acceleration is less at Jupiter than that caused by broadband or stochastic processes, with broadband and stochastic characteristics that are substantially different from those at Earth.

Radial transport of radiation belt electrons in kinetic field-line resonances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaston, Christopher C.; Bonnell, J. W.; Wygant, J. R.

A representative case study from the Van Allen Probes during a geomagnetic storm recovery phase reveals enhanced electron fluxes at intermediate pitch angles over energies from ~100 keV to 5 MeV coincident with broadband low-frequency electromagnetic waves. The statistical properties of these waves are used to build a model for radial diffusion via drift-bounce resonances in kinetic Alfvén eigenmodes/kinetic field-line resonances. Estimated diffusion coefficients indicate timescales for radial transport on the order of hours in storm time events at energies from <100 keV to MeVs over equatorial pitch angles from the edge of the loss cone to nearly perpendicular tomore » the geomagnetic field. In conclusion, the correlation of kinetic resonances with electron depletions and enhancements during storm main phase and recovery, and the rapid diffusion these waves drive, suggests that they may modulate the outer radiation belt.« less

Radial transport of radiation belt electrons in kinetic field-line resonances

DOE PAGES

Chaston, Christopher C.; Bonnell, J. W.; Wygant, J. R.; ...

2017-07-25

A representative case study from the Van Allen Probes during a geomagnetic storm recovery phase reveals enhanced electron fluxes at intermediate pitch angles over energies from ~100 keV to 5 MeV coincident with broadband low-frequency electromagnetic waves. The statistical properties of these waves are used to build a model for radial diffusion via drift-bounce resonances in kinetic Alfvén eigenmodes/kinetic field-line resonances. Estimated diffusion coefficients indicate timescales for radial transport on the order of hours in storm time events at energies from <100 keV to MeVs over equatorial pitch angles from the edge of the loss cone to nearly perpendicular tomore » the geomagnetic field. In conclusion, the correlation of kinetic resonances with electron depletions and enhancements during storm main phase and recovery, and the rapid diffusion these waves drive, suggests that they may modulate the outer radiation belt.« less

Introduction and comparison of next-generation mobile wireless technologies

NASA Astrophysics Data System (ADS)

Zaidi, Syed R.; Hussain, Shahab; Ali, M. A.; Sana, Ajaz; Saddawi, Samir; Carranza, Aparicio

2010-01-01

Mobile networks and services have gone further than voice-only communication services and are rapidly developing towards data-centric services. Emerging mobile data services are expected to see the same explosive growth in demand that Internet and wireless voice services have seen in recent years. To support such a rapid increase in traffic, active users, and advanced multimedia services implied by this growth rate along with the diverse quality of service (QoS) and rate requirements set by these services, mobile operator need to rapidly transition to a simple and cost-effective, flat, all IP-network. This has accelerated the development and deployment of new wireless broadband access technologies including fourth-generation (4G) mobile WiMAX and cellular Long-Term Evolution (LTE). Mobile WiMAX and LTE are two different (but not necessarily competing) technologies that will eventually be used to achieve data speeds of up to 100 Mbps. Speeds that are fast enough to potentially replace wired broadband connections with wireless. This paper introduces both of these next generation technologies and then compares them in the end.

Access and accounting schemes of wireless broadband

NASA Astrophysics Data System (ADS)

Zhang, Jian; Huang, Benxiong; Wang, Yan; Yu, Xing

2004-04-01

In this paper, two wireless broadband access and accounting schemes were introduced. There are some differences in the client and the access router module between them. In one scheme, Secure Shell (SSH) protocol is used in the access system. The SSH server makes the authentication based on private key cryptography. The advantage of this scheme is the security of the user's information, and we have sophisticated access control. In the other scheme, Secure Sockets Layer (SSL) protocol is used the access system. It uses the technology of public privacy key. Nowadays, web browser generally combines HTTP and SSL protocol and we use the SSL protocol to implement the encryption of the data between the clients and the access route. The schemes are same in the radius sever part. Remote Authentication Dial in User Service (RADIUS), as a security protocol in the form of Client/Sever, is becoming an authentication/accounting protocol for standard access to the Internet. It will be explained in a flow chart. In our scheme, the access router serves as the client to the radius server.

Performance Evaluation of Peer-to-Peer Progressive Download in Broadband Access Networks

NASA Astrophysics Data System (ADS)

Shibuya, Megumi; Ogishi, Tomohiko; Yamamoto, Shu

P2P (Peer-to-Peer) file sharing architectures have scalable and cost-effective features. Hence, the application of P2P architectures to media streaming is attractive and expected to be an alternative to the current video streaming using IP multicast or content delivery systems because the current systems require expensive network infrastructures and large scale centralized cache storage systems. In this paper, we investigate the P2P progressive download enabling Internet video streaming services. We demonstrated the capability of the P2P progressive download in both laboratory test network as well as in the Internet. Through the experiments, we clarified the contribution of the FTTH links to the P2P progressive download in the heterogeneous access networks consisting of FTTH and ADSL links. We analyzed the cause of some download performance degradation occurred in the experiment and discussed about the effective methods to provide the video streaming service using P2P progressive download in the current heterogeneous networks.

Quantitative broadband absorption and scattering spectroscopy in turbid media by combined frequency-domain and steady state methodologies

DOEpatents

Tromberg, Bruce J [Irvine, CA; Berger, Andrew J [Rochester, NY; Cerussi, Albert E [Lake Forest, CA; Bevilacqua, Frederic [Costa Mesa, CA; Jakubowski, Dorota [Irvine, CA

2008-09-23

A technique for measuring broadband near-infrared absorption spectra of turbid media that uses a combination of frequency-domain and steady-state reflectance methods. Most of the wavelength coverage is provided by a white-light steady-state measurement, whereas the frequency-domain data are acquired at a few selected wavelengths. Coefficients of absorption and reduced scattering derived from the frequency-domain data are used to calibrate the intensity of the steady-state measurements and to determine the reduced scattering coefficient at all wavelengths in the spectral window of interest. The absorption coefficient spectrum is determined by comparing the steady-state reflectance values with the predictions of diffusion theory, wavelength by wavelength. Absorption spectra of a turbid phantom and of human breast tissue in vivo, derived with the combined frequency-domain and steady-state technique, agree well with expected reference values.

Testing and reference model analysis of FTTH system

NASA Astrophysics Data System (ADS)

Feng, Xiancheng; Cui, Wanlong; Chen, Ying

2009-08-01

With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN , WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network.. Fiber to the Home (FTTH) will be the goal of telecommunications cable broadband access. In accordance with the development trend of telecommunication services, to enhance the capacity of integrated access network, to achieve triple-play (voice, data, image), based on the existing optical Fiber to the curb (FTTC), Fiber To The Zone (FTTZ), Fiber to the Building (FTTB) user optical cable network, the optical fiber can extend to the FTTH system of end-user by using EPON technology. The article first introduced the basic components of FTTH system; and then explain the reference model and reference point for testing of the FTTH system; Finally, by testing connection diagram, the testing process, expected results, primarily analyze SNI Interface Testing, PON interface testing, Ethernet performance testing, UNI interface testing, Ethernet functional testing, PON functional testing, equipment functional testing, telephone functional testing, operational support capability testing and so on testing of FTTH system. ...

Research of application mode for FTTX technology

NASA Astrophysics Data System (ADS)

Wang, Zhong; Yun, Xiang; Huang, Wei

2009-08-01

With rapid development of Internet and broadband access network, the technologies of xDSL, FTTx+LAN, WLAN have more applications, new network service emerges in endless stream, especially the increase of network game, meeting TV, video on demand, etc. FTTH supports all present and future service with enormous bandwidth, including traditional telecommunication service, traditional data service and traditional TV service, and the future digital TV and VOD. With huge bandwidth of FTTH, it wins the final solution of broadband network, becomes the final goal of development of optical access network. In this paper, technique theory of EPON is introduced at first. At the same time, MAC frame structure, automatic detection and ranging of MPCP, DBA,and multi-LLID of EPON is analyzed. Then, service development ability, cost advantage and maintenance superiority based on EPON technology are carried out. At last,with Cost comparison between FTTH / FTTB building model and the traditional model, FTTB + LAN mode which is suitable for the newadding residential users in general areas and FTTN + DSL mode which is suitable for the old city and rural access network transformation are built up in detail. And FTTN + DSL project of rural information in rural areas and FTTH broadband HOUSE project on service solutions program are analyzed. comparing to the traditional access technologies, EPON technology has the obvious advantages, such as distance transmission, high or wide band, saving line resources, service abilities, etc. These are the qualities which not only be served for home users, but solve more access problems for us effectively.

Image encryption using a synchronous permutation-diffusion technique

NASA Astrophysics Data System (ADS)

Enayatifar, Rasul; Abdullah, Abdul Hanan; Isnin, Ismail Fauzi; Altameem, Ayman; Lee, Malrey

2017-03-01

In the past decade, the interest on digital images security has been increased among scientists. A synchronous permutation and diffusion technique is designed in order to protect gray-level image content while sending it through internet. To implement the proposed method, two-dimensional plain-image is converted to one dimension. Afterward, in order to reduce the sending process time, permutation and diffusion steps for any pixel are performed in the same time. The permutation step uses chaotic map and deoxyribonucleic acid (DNA) to permute a pixel, while diffusion employs DNA sequence and DNA operator to encrypt the pixel. Experimental results and extensive security analyses have been conducted to demonstrate the feasibility and validity of this proposed image encryption method.

A Low-Temperature, Solution-Processable, Cu-Doped Nickel Oxide Hole-Transporting Layer via the Combustion Method for High-Performance Thin-Film Perovskite Solar Cells

DOE PAGES

Jung, Jae Woong; Chueh, Chu-Chen; Jen, Alex K. -Y.

2015-10-20

The promising photophysical properties of the emerging organometallic halide perovskites, such as intense broadband absorption, high charge carrier mobility, and long charge diffusion length, have enabled the rapid development in solar cells reaching over 20% power conversion effi ciency (PCE) recently. Especially, the low material cost and facile solution processability of perovskites are very attractive as next-generation photovoltaic materials for sustainable energy.

An Information Theory-Inspired Strategy for Design of Re-programmable Encrypted Graphene-based Coding Metasurfaces at Terahertz Frequencies.

PubMed

Momeni, Ali; Rouhi, Kasra; Rajabalipanah, Hamid; Abdolali, Ali

2018-04-18

Inspired by the information theory, a new concept of re-programmable encrypted graphene-based coding metasurfaces was investigated at terahertz frequencies. A channel-coding function was proposed to convolutionally record an arbitrary information message onto unrecognizable but recoverable parity beams generated by a phase-encrypted coding metasurface. A single graphene-based reflective cell with dual-mode biasing voltages was designed to act as "0" and "1" meta-atoms, providing broadband opposite reflection phases. By exploiting graphene tunability, the proposed scheme enabled an unprecedented degree of freedom in the real-time mapping of information messages onto multiple parity beams which could not be damaged, altered, and reverse-engineered. Various encryption types such as mirroring, anomalous reflection, multi-beam generation, and scattering diffusion can be dynamically attained via our multifunctional metasurface. Besides, contrary to conventional time-consuming and optimization-based methods, this paper convincingly offers a fast, straightforward, and efficient design of diffusion metasurfaces of arbitrarily large size. Rigorous full-wave simulations corroborated the results where the phase-encrypted metasurfaces exhibited a polarization-insensitive reflectivity less than -10 dB over a broadband frequency range from 1 THz to 1.7 THz. This work reveals new opportunities for the extension of re-programmable THz-coding metasurfaces and may be of interest for reflection-type security systems, computational imaging, and camouflage technology.

Estimation of atmospheric turbidity and surface radiative parameters using broadband clear sky solar irradiance models in Rio de Janeiro-Brasil

NASA Astrophysics Data System (ADS)

Flores, José L.; Karam, Hugo A.; Marques Filho, Edson P.; Pereira Filho, Augusto J.

2016-02-01

The main goal of this paper is to estimate a set of optimal seasonal, daily, and hourly values of atmospheric turbidity and surface radiative parameters Ångström's turbidity coefficient ( β), Ångström's wavelength exponent ( α), aerosol single scattering albedo ( ω o ), forward scatterance ( F c ) and average surface albedo ( ρ g ), using the Brute Force multidimensional minimization method to minimize the difference between measured and simulated solar irradiance components, expressed as cost functions. In order to simulate the components of short-wave solar irradiance (direct, diffuse and global) for clear sky conditions, incidents on a horizontal surface in the Metropolitan Area of Rio de Janeiro (MARJ), Brazil (22° 51' 27″ S, 43° 13' 58″ W), we use two parameterized broadband solar irradiance models, called CPCR2 and Iqbal C, based on synoptic information. The meteorological variables such as precipitable water ( u w ) and ozone concentration ( u o ) required by the broadband solar models were obtained from moderate-resolution imaging spectroradiometer (MODIS) sensor on Terra and Aqua NASA platforms. For the implementation and validation processes, we use global and diffuse solar irradiance data measured by the radiometric platform of LabMiM, located in the north area of the MARJ. The data were measured between the years 2010 and 2012 at 1-min intervals. The performance of solar irradiance models using optimal parameters was evaluated with several quantitative statistical indicators and a subset of measured solar irradiance data. Some daily results for Ångström's wavelength exponent α were compared with Ångström's parameter (440-870 nm) values obtained by aerosol robotic network (AERONET) for 11 days, showing an acceptable level of agreement. Results for Ångström's turbidity coefficient β, associated with the amount of aerosols in the atmosphere, show a seasonal pattern according with increased precipitation during summer months (December-February) in the MARJ.

Digital Avionics

NASA Technical Reports Server (NTRS)

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

2003-01-01

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

BRDF Calibration of Sintered PTFE in the SWIR

NASA Technical Reports Server (NTRS)

Georgiev, Georgi T.; Butler, James J.

2009-01-01

Satellite instruments operating in the reflective solar wavelength region often require accurate and precise determination of the Bidirectional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in their pre-flight calibrations and ground-based support of on-orbit remote sensing instruments. The Diffuser Calibration Facility at NASA's Goddard Space Flight Center is a secondary diffuser calibration standard after NEST for over two decades, providing numerous NASA projects with BRDF data in the UV, Visible and the NIR spectral regions. Currently the Diffuser Calibration Facility extended the covered spectral range from 900 nm up to 1.7 microns. The measurements were made using the existing scatterometer by replacing the Si photodiode based receiver with an InGaAs-based one. The BRDF data was recorded at normal incidence and scatter zenith angles from 10 to 60 deg. Tunable coherent light source was setup. Broadband light source application is under development. Gray-scale sintered PTFE samples were used at these first trials, illuminated with P and S polarized incident light. The results are discussed and compared to empirically generated BRDF data from simple model based on 8 deg directional/hemispherical measurements.

A SUCCESSFUL BROADBAND SURVEY FOR GIANT Ly{alpha} NEBULAE. II. SPECTROSCOPIC CONFIRMATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prescott, Moire K. M.; Dey, Arjun; Jannuzi, Buell T., E-mail: mkpresco@physics.ucsb.edu

2013-01-01

Using a systematic broadband search technique, we have carried out a survey for large Ly{alpha} nebulae (or Ly{alpha} {sup b}lobs{sup )} at 2 {approx}< z {approx}< 3 within 8.5 deg{sup 2} of the NOAO Deep Wide-Field Survey Booetes field, corresponding to a total survey comoving volume of Almost-Equal-To 10{sup 8} h {sup -3} {sub 70} Mpc{sup 3}. Here, we present our spectroscopic observations of candidate giant Ly{alpha} nebulae. Of 26 candidates targeted, 5 were confirmed to have Ly{alpha} emission at 1.7 {approx}< z {approx}< 2.7, 4 of which were new discoveries. The confirmed Ly{alpha} nebulae span a range of Ly{alpha}more » equivalent widths, colors, sizes, and line ratios, and most show spatially extended continuum emission. The remaining candidates did not reveal any strong emission lines, but instead exhibit featureless, diffuse, blue continuum spectra. Their nature remains mysterious, but we speculate that some of these might be Ly{alpha} nebulae lying within the redshift desert (i.e., 1.2 {approx}< z {approx}< 1.6). Our spectroscopic follow-up confirms the power of using deep broadband imaging to search for the bright end of the Ly{alpha} nebula population across enormous comoving volumes.« less

Data Release of UV to Submillimeter Broadband Fluxes for Simulated Galaxies from the EAGLE Project

NASA Astrophysics Data System (ADS)

Camps, Peter; Trčka, Ana; Trayford, James; Baes, Maarten; Theuns, Tom; Crain, Robert A.; McAlpine, Stuart; Schaller, Matthieu; Schaye, Joop

2018-02-01

We present dust-attenuated and dust emission fluxes for sufficiently resolved galaxies in the EAGLE suite of cosmological hydrodynamical simulations, calculated with the SKIRT radiative transfer code. The post-processing procedure includes specific components for star formation regions, stellar sources, and diffuse dust and takes into account stochastic heating of dust grains to obtain realistic broadband fluxes in the wavelength range from ultraviolet to submillimeter. The mock survey includes nearly half a million simulated galaxies with stellar masses above {10}8.5 {M}ȯ across six EAGLE models. About two-thirds of these galaxies, residing in 23 redshift bins up to z = 6, have a sufficiently resolved metallic gas distribution to derive meaningful dust attenuation and emission, with the important caveat that the same dust properties were used at all redshifts. These newly released data complement the already publicly available information about the EAGLE galaxies, which includes intrinsic properties derived by aggregating the properties of the smoothed particles representing matter in the simulation. We further provide an open-source framework of Python procedures for post-processing simulated galaxies with the radiative transfer code SKIRT. The framework allows any third party to calculate synthetic images, spectral energy distributions, and broadband fluxes for EAGLE galaxies, taking into account the effects of dust attenuation and emission.

Broadband Electrophysiological Dynamics Contribute to Global Resting-State fMRI Signal.

PubMed

Wen, Haiguang; Liu, Zhongming

2016-06-01

Spontaneous activity observed with resting-state fMRI is used widely to uncover the brain's intrinsic functional networks in health and disease. Although many networks appear modular and specific, global and nonspecific fMRI fluctuations also exist and both pose a challenge and present an opportunity for characterizing and understanding brain networks. Here, we used a multimodal approach to investigate the neural correlates to the global fMRI signal in the resting state. Like fMRI, resting-state power fluctuations of broadband and arrhythmic, or scale-free, macaque electrocorticography and human magnetoencephalography activity were correlated globally. The power fluctuations of scale-free human electroencephalography (EEG) were coupled with the global component of simultaneously acquired resting-state fMRI, with the global hemodynamic change lagging the broadband spectral change of EEG by ∼5 s. The levels of global and nonspecific fluctuation and synchronization in scale-free population activity also varied across and depended on arousal states. Together, these results suggest that the neural origin of global resting-state fMRI activity is the broadband power fluctuation in scale-free population activity observable with macroscopic electrical or magnetic recordings. Moreover, the global fluctuation in neurophysiological and hemodynamic activity is likely modulated through diffuse neuromodulation pathways that govern arousal states and vigilance levels. This study provides new insights into the neural origin of resting-state fMRI. Results demonstrate that the broadband power fluctuation of scale-free electrophysiology is globally synchronized and directly coupled with the global component of spontaneous fMRI signals, in contrast to modularly synchronized fluctuations in oscillatory neural activity. These findings lead to a new hypothesis that scale-free and oscillatory neural processes account for global and modular patterns of functional connectivity observed with resting-state fMRI, respectively. Copyright © 2016 the authors 0270-6474/16/366030-11$15.00/0.

A Comparison Between Modeled and Measured Clear-Sky Radiative Shortwave Fluxes in Arctic Environments, with Special Emphasis on Diffuse Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnard, James C.; Flynn, Donna M.

2002-10-08

The ability of the SBDART radiative transfer model to predict clear-sky diffuse and direct normal broadband shortwave irradiances is investigated. Model calculations of these quantities are compared with data from the Atmospheric Radiation Measurement (ARM) program’s Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites. The model tends to consistently underestimate the direct normal irradiances at both sites by about 1%. In regards to clear-sky diffuse irradiance, the model overestimates this quantity at the SGP site in a manner similar to what has been observed in other studies (Halthore and Schwartz, 2000). The difference between the diffuse SBDARTmore » calculations and Halthore and Schwartz’s MODTRAN calculations is very small, thus demonstrating that SBDART performs similarly to MODTRAN. SBDART is then applied to the NSA site, and here it is found that the discrepancy between the model calculations and corrected diffuse measurements (corrected for daytime offsets, Dutton et al., 2001) is 0.4 W/m2 when averaged over the 12 cases considered here. Two cases of diffuse measurements from a shaded “black and white” pyranometer are also compared with the calculations and the discrepancy is again minimal. Thus, it appears as if the “diffuse discrepancy” that exists at the SGP site does not exist at the NSA sites. We cannot yet explain why the model predicts diffuse radiation well at one site but not at the other.« less

Jet noise suppression

NASA Astrophysics Data System (ADS)

Gliebe, P. R.; Brausch, J. F.; Majjigi, R. K.; Lee, R.

1991-08-01

The objectives of this chapter are to review and summarize the jet noise suppression technology, to provide a physical and theoretical model to explain the measured jet noise suppression characteristics of different concepts, and to provide a set of guidelines for evolving jet noise suppression designs. The underlying principle for all jet noise suppression devices is to enhance rapid mixing (i.e., diffusion) of the jet plume by geometric and aerothermodynamic means. In the case of supersonic jets, the shock-cell broadband noise reduction is effectively accomplished by the elimination or mitigation of the shock-cell structure. So far, the diffusion concepts have predominantly concentrated on jet momentum and energy (kinetic and thermal) diffusion, in that order, and have yielded better noise reduction than the simple conical nozzles. A critical technology issue that needs resolution is the effect of flight on the noise suppression potential of mechanical suppressor nozzles. A more thorough investigation of this mechanism is necessary for the successful development and design of an acceptable noise suppression device for future high-speed civil transports.

Disruptive Potential of the Internet to Transform Illicit Drug Markets and Impact on Future Patterns of Drug Consumption.

PubMed

Griffiths, P; Mounteney, J

2017-02-01

The internet facilitates rapid and covert communication, knowledge transfer, and has the potential to disrupt and transform drug market models and associated consumption patterns. Innovation and new trends diffuse rapidly through this medium and new operational models are emerging. Although the online drug markets currently only account for a small share of all drug transactions, the potential of the surface and deep web to provide a new platform for drug sale and exchanges is considerable. © 2016 American Society for Clinical Pharmacology and Therapeutics.

“I Found it on the Internet”

PubMed Central

Masters, Ken; Ng’ambi, Dick; Todd, Gail

2010-01-01

In the Information Age, the communication patterns between doctor and patient are changing. Using Everett Rogers’ theory of Diffusion of Innovations, this paper begins by examining the diffusion of the Internet in the world and in Oman. It then considers the emergence of e-patients. The characteristics of e-patients are described in some detail. The paper ends by describing steps that should be taken when teaching medical students in Oman so that they can be prepared for e-patients. PMID:21509226

Voice Over Internet Protocol (VoIP) in a Control Center Environment

NASA Technical Reports Server (NTRS)

Pirani, Joseph; Calvelage, Steven

2010-01-01

The technology of transmitting voice over data networks has been available for over 10 years. Mass market VoIP services for consumers to make and receive standard telephone calls over broadband Internet networks have grown in the last 5 years. While operational costs are less with VoIP implementations as opposed to time division multiplexing (TDM) based voice switches, is it still advantageous to convert a mission control center s voice system to this newer technology? Marshall Space Flight Center (MSFC) Huntsville Operations Support Center (HOSC) has converted its mission voice services to a commercial product that utilizes VoIP technology. Results from this testing, design, and installation have shown unique considerations that must be addressed before user operations. There are many factors to consider for a control center voice design. Technology advantages and disadvantages were investigated as they refer to cost. There were integration concerns which could lead to complex failure scenarios but simpler integration for the mission infrastructure. MSFC HOSC will benefit from this voice conversion with less product replacement cost, less operations cost and a more integrated mission services environment.

Unbundled infrastructure firms: Competition and continuing regulation

NASA Astrophysics Data System (ADS)

Hogendorn, Christiaan Paul

Unbundled infrastructure firms provide conduits for electricity transmission, residential communications, etc. but are vertically disintegrated from "content" functions such as electricity generation or world-wide-web pages. These conduits are being deregulated, and this dissertation examines whether the deregulated conduits will behave in an efficient and competitive manner. The dissertation presents three essays, each of which develops a theoretical model of the behavior of conduit firms in a market environment. The first essay considers the prospects for competition between multiple conduits in the emerging market for broadband (high-speed) residential Internet access. It finds that such competition is likely to emerge as demand for these services increase. The second essay shows how a monopoly electricity or natural gas transmission conduit can facilitate collusion between suppliers of the good. It shows that this is an inefficient effect of standard price-cap regulation. The third essay considers the supply chain of residential Internet access and evaluates proposed "open access" regulation that would allow more than one firm to serve customers over the same physical infrastructure. It shows that the amount of content available to consumers does not necessarily increase under open access.

Broadband Solar Energy Harvesting in Single Nanowire Resonators

NASA Astrophysics Data System (ADS)

Yang, Yiming; Peng, Xingyue; Hyatt, Steven; Yu, Dong

2015-03-01

Sub-wavelength semiconductor nanowires (NWs) can have optical absorption cross sections far beyond their physical sizes at resonance frequencies, offering a powerful method to simultaneously lower the material consumption and enhance photovoltaic performance. The degree of absorption enhancement is expected to substantially increase in materials with high refractive indices, but this has not yet been experimentally demonstrated. Here, we show that the absorption efficiency can be significantly improved in high-index NWs, by a direct observation of 350% external quantum efficiency (EQE) in lead sulfide (PbS) NWs. Broadband absorption enhancement is also realized in tapered NWs, where light of different wavelength is absorbed at segments with different diameters analogous to a tandem solar cell. Our results quantitatively agree with the finite-difference-time-domain (FDTD) simulations. Overall, our single PbS NW Schottky solar cells taking advantage of optical resonance, near bandgap open circuit voltage, and long minority carrier diffusion length exhibit power conversion efficiency comparable to single Si NW coaxial p-n junction cells, while the fabrication complexity is greatly reduced.

Network-based reading system for lung cancer screening CT

NASA Astrophysics Data System (ADS)

Fujino, Yuichi; Fujimura, Kaori; Nomura, Shin-ichiro; Kawashima, Harumi; Tsuchikawa, Megumu; Matsumoto, Toru; Nagao, Kei-ichi; Uruma, Takahiro; Yamamoto, Shinji; Takizawa, Hotaka; Kuroda, Chikazumi; Nakayama, Tomio

2006-03-01

This research aims to support chest computed tomography (CT) medical checkups to decrease the death rate by lung cancer. We have developed a remote cooperative reading system for lung cancer screening over the Internet, a secure transmission function, and a cooperative reading environment. It is called the Network-based Reading System. A telemedicine system involves many issues, such as network costs and data security if we use it over the Internet, which is an open network. In Japan, broadband access is widespread and its cost is the lowest in the world. We developed our system considering human machine interface and security. It consists of data entry terminals, a database server, a computer aided diagnosis (CAD) system, and some reading terminals. It uses a secure Digital Imaging and Communication in Medicine (DICOM) encrypting method and Public Key Infrastructure (PKI) based secure DICOM image data distribution. We carried out an experimental trial over the Japan Gigabit Network (JGN), which is the testbed for the Japanese next-generation network, and conducted verification experiments of secure screening image distribution, some kinds of data addition, and remote cooperative reading. We found that network bandwidth of about 1.5 Mbps enabled distribution of screening images and cooperative reading and that the encryption and image distribution methods we proposed were applicable to the encryption and distribution of general DICOM images via the Internet.

Influence of Acoustic Reflection on the Inertial Cavitation Dose in a Franz Diffusion Cell.

PubMed

Robertson, Jeremy; Becker, Sid

2018-05-01

The exposure of the skin to low-frequency (20-100 kHz) ultrasound is a well-established method for increasing its permeability to drugs. The mechanism underlying this permeability increase has been found to be inertial cavitation within the coupling fluid. This study investigated the influence of acoustic reflections on the inertial cavitation dose during low-frequency (20 kHz) exposure in an in vitro skin sonoporation setup. This investigation was conducted using a passive cavitation detector that monitored the broadband noise emission within a modified Franz diffusion cell. Two versions of this diffusion cell were employed. One version had acoustic conditions that were similar to those of a standard Franz diffusion cell surrounded by air, whereas the second was designed to greatly reduce the acoustic reflection by submerging the diffusion cell in a water bath. The temperature of the coupling fluid in both setups was controlled using a novel thermoelectric cooling system. At an ultrasound intensity of 13.6 W/cm 2 , the median inertial cavitation dose when the acoustic reflections were suppressed, was found to be only about 15% lower than when reflections were not suppressed. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

A Rayleighian approach for modeling kinetics of ionic transport in polymeric media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Rajeev

2017-02-14

Here, we report a theoretical approach for analyzing impedance of ionic liquids (ILs) and charged polymers such as polymerized ionic liquids (PolyILs) within linear response. The approach is based on the Rayleigh dissipation function formalism, which provides a computational framework for a systematic study of various factors, including polymer dynamics, in affecting the impedance. We present an analytical expression for the impedance within linear response by constructing a one-dimensional model for ionic transport in ILs/PolyILs. This expression is used to extract mutual diffusion constants, the length scale of mutual diffusion, and thicknesses of a low-dielectric layer on the electrodes frommore » the broadband dielectric spectroscopy (BDS) measurements done for an IL and three PolyILs. Also, static dielectric permittivities of the IL and the PolyILs are determined. The extracted mutual diffusion constants are compared with the self diffusion constants of ions measured using pulse field gradient (PFG) fluorine nuclear magnetic resonance (NMR). For the first time, excellent agreements between the diffusivities extracted from the Electrode Polarization spectra (EPS) of IL/PolyILs and those measured using the PFG-NMR are found, which allows the use of the EPS and the PFG-NMR techniques in a complimentary manner for a general understanding of the ionic transport.« less

Multimedia And Internetworking Architecture Infrastructure On Interactive E-Learning System

NASA Astrophysics Data System (ADS)

Indah, K. A. T.; Sukarata, G.

2018-01-01

Interactive e-learning is a distance learning method that involves information technology, electronic system or computer as one means of learning system used for teaching and learning process that is implemented without having face to face directly between teacher and student. A strong dependence on emerging technologies greatly influences the way in which the architecture is designed to produce a powerful interactive e-learning network. In this paper analyzed an architecture model where learning can be done interactively, involving many participants (N-way synchronized distance learning) using video conferencing technology. Also used broadband internet network as well as multicast techniques as a troubleshooting method for bandwidth usage can be efficient.

Zoning Issues and Area of Interest Management in Massively Multiplayer Online Games

NASA Astrophysics Data System (ADS)

Ahmed, Dewan Tanvir; Shirmohammadi, Shervin

Game is a way of entertainment, a means for excitement, fun and socialization. Online games have achieved popularity due to increasing broadband adoption among consumers. Relatively cheap bandwidth Internet connections allow large number of players to play together. Since the introduction of Network Virtual Environment (NVE) in 1980s for military simulation, many interesting applications have been evolved over the past few decades. Massively multiplayer online (role-playing) game, MMOG or MMORPG, is a new genre of online games that has emerged with the introduction of Ultima since 1997. It is a kind of online computer game with the participation of hundreds of thousands of players in a virtual world.

On the Radio-emitting Particles of the Crab Nebula: Stochastic Acceleration Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, Shuta J.; Asano, Katsuaki, E-mail: sjtanaka@center.konan-u.ac.jp

The broadband emission of pulsar wind nebulae (PWNe) is well described by non-thermal emissions from accelerated electrons and positrons. However, the standard shock acceleration model of PWNe does not account for the hard spectrum in radio wavelengths. The origin of the radio-emitting particles is also important to determine the pair production efficiency in the pulsar magnetosphere. Here, we propose a possible resolution for the particle energy distribution in PWNe; the radio-emitting particles are not accelerated at the pulsar wind termination shock but are stochastically accelerated by turbulence inside PWNe. We upgrade our past one-zone spectral evolution model to include themore » energy diffusion, i.e., the stochastic acceleration, and apply the model to the Crab Nebula. A fairly simple form of the energy diffusion coefficient is assumed for this demonstrative study. For a particle injection to the stochastic acceleration process, we consider the continuous injection from the supernova ejecta or the impulsive injection associated with supernova explosion. The observed broadband spectrum and the decay of the radio flux are reproduced by tuning the amount of the particle injected to the stochastic acceleration process. The acceleration timescale and the duration of the acceleration are required to be a few decades and a few hundred years, respectively. Our results imply that some unveiled mechanisms, such as back reaction to the turbulence, are required to make the energies of stochastically and shock-accelerated particles comparable.« less

Unsteady behavior and control of vortices in centrifugal compressor

NASA Astrophysics Data System (ADS)

Ohta, Yutaka; Fujisawa, Nobumichi

2014-10-01

Two examples of the use of vortex control to reduce noise and enhance the stable operating range of a centrifugal compressor are presented in this paper. In the case of high-flow operation of a centrifugal compressor with a vaned diffuser, a discrete frequency noise induced by interaction between the impeller-discharge flow and the diffuser vane, which appears most notably in the power spectra of the radiated noise, can be reduced using a tapered diffuser vane (TDV) without affecting the performance of the compressor. Twin longitudinal vortices produced by leakage flow passing through the tapered portion of the diffuser vane induce secondary flow in the direction of the blade surface and prevent flow separation from the leading edge of the diffuser. The use of a TDV can effectively reduce both the discrete frequency noise generated by the interaction between the impeller-discharge flow and the diffuser surface and the broadband turbulent noise component. In the case of low-flow operation, a leading-edge vortex (LEV) that forms on the shroud side of the suction surface near the leading edge of the diffuser increases significantly in size and blocks flow in the diffuser passage. The formation of an LEV may adversely affect the performance of the compressor and may cause the diffuser to stall. Using a one-side tapered diffuser vane to suppress the evolution of an LEV, the stable operating range of the compressor can be increased by more than 12 percent, and the pressure-rise characteristics of the compressor can be improved. The results of a supplementary examination of the structure and unsteady behavior of LEVs, conducted by means of detailed numerical simulations, are also presented.

The measurement and analysis of normal incidence solar UVB radiation and its application to the photoclimatherapy protocol for psoriasis at the Dead Sea, Israel.

PubMed

Kudish, Avraham I; Harari, Marco; Evseev, Efim G

2011-01-01

The broad-band normal incidence UVB beam radiation has been measured at Neve Zohar, Dead Sea basin, using a prototype tracking instrument composed of a Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The diffuse and beam fraction of the solar global UVB radiation have been determined using the concurrently measured solar global UVB radiation. The diffuse fraction was observed to exceed 80% throughout the year. The application of the results of these measurements to the possible revision of the photoclimatherapy protocol for psoriasis patients at the Dead Sea medical spas is now under investigation. The suggested revision would enable the sun-exposure treatment protocol to take advantage of the very high diffuse fraction by allowing the patient to receive the daily dose of UVB radiation without direct exposure to the sun, viz. receive the diffuse UVB radiation under a sunshade. This would require an increase in sun-exposure time intervals, as the UVB radiation intensity beneath a sunshade is less than that on an exposed surface. © 2010 The Authors. Photochemistry and Photobiology © 2010 The American Society of Photobiology.

Diffusive-light invisibility cloak for transient illumination

NASA Astrophysics Data System (ADS)

Orazbayev, B.; Beruete, M.; Martínez, A.; García-Meca, C.

2016-12-01

Invisibility in a diffusive-light-scattering medium has been recently demonstrated by employing a scattering-cancellation core-shell cloak. Unlike nondiffusive cloaks, such a device can be simultaneously macroscopic, broadband, passive, polarization independent, and omnidirectional. Unfortunately, it has been verified that this cloak, as well as more sophisticated ones based on transformation optics, fail under pulsed illumination, invalidating their use for a variety of applications. Here, we introduce a different approach based on unimodular transformations that enables the construction of unidirectional diffusive-light cloaks exhibiting a perfect invisibility effect, even under transient conditions. Moreover, we demonstrate that a polygonal cloak can extend this functionality to multiple directions with a nearly ideal behavior, while preserving all other features. We propose and numerically verify a simple cloak realization based on a layered stack of two isotropic materials. The studied devices have several applications not addressable by any of the other cloaks proposed to date, including shielding from pulse-based detection techniques, cloaking undesired scattering elements in time-of-flight imaging or high-speed communication systems for diffusive environments, and building extreme optical security features. The discussed cloaking strategy could also be applied to simplify the implementation of thermal cloaks.

Digital Storytelling in the Language Arts Classroom

ERIC Educational Resources Information Center

Bull, Glen; Kajder, Sara

2005-01-01

Technology offers a number of opportunities for connecting classrooms with the world. The advent of the Internet has offered unprecedented prospects for classroom connections, but the recent diffusion of digital cameras throughout society offers instructional possibilities as well. This document provides a detailed examination of digital…

Pitch Angle Scattering of Upgoing Electron Beams in Jupiter's Polar Regions by Whistler Mode Waves

NASA Astrophysics Data System (ADS)

Elliott, S. S.; Gurnett, D. A.; Kurth, W. S.; Clark, G.; Mauk, B. H.; Bolton, S. J.; Connerney, J. E. P.; Levin, S. M.

2018-02-01

The Juno spacecraft's Jupiter Energetic-particle Detector Instrument has observed field-aligned, unidirectional (upgoing) electron beams throughout most of Jupiter's entire polar cap region. The Waves instrument detected intense broadband whistler mode emissions occurring in the same region. In this paper, we investigate the pitch angle scattering of the upgoing electron beams due to interactions with the whistler mode waves. Profiles of intensity versus pitch angle for electron beams ranging from 2.53 to 7.22 Jovian radii show inconsistencies with the expected adiabatic invariant motion of the electrons. It is believed that the observed whistler mode waves perturb the electron motion and scatter them away from the magnetic field line. The diffusion equation has been solved by using diffusion coefficients which depend on the magnetic intensity of the whistler mode waves.

Peru Subduction Zone Seismic Experiment (PeruSZE): Preliminary Results From a Seismic Network Between Mollendo and Lake Titicaca, Peru.

NASA Astrophysics Data System (ADS)

Guy, R.; Stubailo, I.; Skinner, S.; Phillips, K.; Foote, E.; Lukac, M.; Aguilar, V.; Tavera, H.; Audin, L.; Husker, A.; Clayton, R.; Davis, P. M.

2008-12-01

This work describes preliminary results from a 50 station broadband seismic network recently installed from the coast to the high Andes in Peru. UCLA's Center for Embedded Network Sensing (CENS) and Caltech's Tectonic Observatory are collaborating with the IRD (French L'Institut de Recherche pour le Developpement) and the Institute of Geophysics, in Lima Peru in a broadband seismic experiment that will study the transition from steep to shallow slab subduction. The currently installed line has stations located above the steep subduction zone at a spacing of about 6 km. In 2009 we plan to install a line of 50 stations north from this line along the crest of the Andes, crossing the transition from steep to shallow subduction. A further line from the end of that line back to the coast, completing a U shaped array, is in the planning phase. The network is wirelessly linked using multi-hop network software designed by computer scientists in CENS in which data is transmitted from station to station, and collected at Internet drops, from where it is transmitted over the Internet to CENS each night. The instrument installation in Peru is almost finished and we have been receiving data daily from 10 stations (out of total 50) since June 2008. The rest are recording on-site while the RF network is being completed. The software system provides dynamic link quality based routing, reliable data delivery, and a disruption tolerant shell interface for managing the system from UCLA without the need to travel to Peru. The near real-time data delivery also allows immediate detection of any problems at the sites. We are building a seismic data and GPS quality control toolset that would greatly minimize the station's downtime by alerting the users of any possible problems.

The Role of the Army in Infrastructure and Capacity Building

DTIC Science & Technology

2010-02-01

Issues Volume I: Theory of War and Strategy 3rd edition, ed. J. Boone Bartholomees, Jr. (Carlisle: USAWC Strategic Studies Institute, 2009), 145...efforts. 34 Raj M. Desai and Homi Kharas, Do Philanthropic Citizens Behave Like Governments? Internet-Based Platforms and the Diffusion of International

A small Internet controllable observatory for research and education at the University of North Dakota

NASA Astrophysics Data System (ADS)

Hardersen, P. S.; de Silva, S.; Reddy, V.; Cui, P.; Kumar, S.; Gaffey, M. J.

2006-06-01

One of the challenges in astronomy education today is to introduce college students to the real-world practice and science of observational astronomy. Along with a good theoretical background, college students can gain an earlier, deeper understanding of the astronomy profession through direct observational and data reduction experience. However, building and managing a modest observatory is still too costly for many colleges and universities. Fortunately, advances in commercial astronomical hardware and software now allow universities to build and operate small Internet controllable observatories for a modest investment. The advantages of an Internet observatory include: 1) remote operation from a comfortable location, 2) immediate data access, 3) telescope control via a web browser, and 4) allowing both on-campus and distance education students the ability to conduct a variety of observing projects. Internet capabilities vastly expand the number of students who will be able to use the observatory, thus exposing them to astronomy as a science and as a potential career. In September 2005, the University of North Dakota (UND) Department of Space Studies began operating a small, recently renovated Internet controllable observatory. Housed within a roll-off roof 10 miles west of UND, the observatory includes a Meade 16-inch, f/10 Schmidt-Cassegrain telescope, an SBIG STL-6303e CCD with broadband filters, ACP observatory control software, focuser, and associated equipment. The observatory cost \\25,000 to build in 1996; 2005 renovation costs total \\28,000. An observatory operator prepares the telescope for use each night. Through remote operation, the roof is opened and the telescope/CCD power is turned on. The telescope is then aligned and focused before allowing students to access the observatory. Students communicate with the observatory operator via an online chat room and via telephone, if necessary, to answer questions and resolve any problems. Additional observatory enhancements are planned for installation and testing in 2006.

An economic analysis on optical Ethernet in the access network

NASA Astrophysics Data System (ADS)

Kim, Sung Hwi; Nam, Dohyun; Yoo, Gunil; Kim, WoonHa

2004-04-01

Nowadays, Broadband service subscribers have increased exponentially and have almost saturated in Korea. Several types of solutions for broadband service applied to the field. Among several types of broadband services, most of subscribers provided xDSL service like ADSL or VDSL. Usually, they who live in an apartment provided Internet service by Ntopia network as FTTC structure that is a dormant network in economical view at KT. Under competitive telecom environment for new services like video, we faced with needing to expand or rebuild portions of our access networks, are looking for ways to provide any service that competitors might offer presently or in the near future. In order to look for new business model like FTTH service, we consider deploying optical access network. In spite of numerous benefits of PON until now, we cannot believe that PON is the best solution in Korea. Because we already deployed optical access network of ring type feeder cable and have densely population of subscribers that mainly distributed inside 6km from central office. So we try to utilize an existing Ntopia network for FTTH service under optical access environment. Despite of such situations, we try to deploy PON solution in the field as FTTC or FTTH architecture. Therefore we analyze PON structure in comparison with AON structure in order to look for optimized structure in Korea. At first, we describe the existing optical access networks and network architecture briefly. Secondly we investigate the cost of building optical access networks by modeling cost functions on AON and PON structure which based on Ethernet protocol, and analyze two different network architectures according to different deployment scenarios: Urban, small town, rural. Finally we suggest the economic and best solution with PON structure to optimize to optical access environment of KT.

Influence Diffusion Model in Text-Based Communication

NASA Astrophysics Data System (ADS)

Matsumura, Naohiro; Ohsawa, Yukio; Ishizuka, Mitsuru

Business people, especially marketing researchers, are keen to understand peoples' potential sense of value to create fascinating topics stimulating peoples' interest. In this paper, we aim at finding influential people, comments, and terms contributing the discovery of such topics. For this purpose, we propose an Influence Diffusion Model in text-based communication, where the influence of people, comments, and terms are defined as the degree of text-based relevance of messages. We apply this model to Bulletin Board Service(BBS) on the Internet, and present our discoveries on experimental evaluations.

Barriers and facilitators to home computer and internet use among urban novice computer users of low socioeconomic position.

PubMed

Kontos, Emily Z; Bennett, Gary G; Viswanath, K

2007-10-22

Despite the increasing penetration of the Internet and amount of online health information, there are significant barriers that limit its widespread adoption as a source of health information. One is the "digital divide," with people of higher socioeconomic position (SEP) demonstrating greater access and usage compared to those from lower SEP groups. However, as the access gap narrows over time and more people use the Internet, a shift in research needs to occur to explore how one might improve Internet use as well as website design for a range of audiences. This is particularly important in the case of novice users who may not have the technical skills, experience, or social connections that could help them search for health information using the Internet. The focus of our research is to investigate the challenges in the implementation of a project to improve health information seeking among low SEP groups. The goal of the project is not to promote health information seeking as much as to understand the barriers and facilitators to computer and Internet use, beyond access, among members of lower SEP groups in an urban setting. The purpose was to qualitatively describe participants' self-identified barriers and facilitators to computer and Internet use during a 1-year pilot study as well as the challenges encountered by the research team in the delivery of the intervention. Between August and November 2005, 12 low-SEP urban individuals with no or limited computer and Internet experience were recruited through a snowball sampling. Each participant received a free computer system, broadband Internet access, monthly computer training courses, and technical support for 1 year as the intervention condition. Upon completion of the study, participants were offered the opportunity to complete an in-depth semistructured interview. Interviews were approximately 1 hour in length and were conducted by the project director. The interviews were held in the participants' homes and were tape recorded for accuracy. Nine of the 12 study participants completed the semistructured interviews. Members of the research team conducted a qualitative analysis based on the transcripts from the nine interviews using the crystallization/immersion method. Nine of the 12 participants completed the in-depth interview (75% overall response rate), with three men and six women agreeing to be interviewed. Major barriers to Internet use that were mentioned included time constraints and family conflict over computer usage. The monthly training classes and technical assistance components of the intervention surfaced as the most important facilitators to computer and Internet use. The concept of received social support from other study members, such as assistance with computer-related questions, also emerged as an important facilitator to overall computer usage. This pilot study offers important insights into the self-identified barriers and facilitators in computer and Internet use among urban low-SEP novice users as well as the challenges faced by the research team in implementing the intervention.

ATM over hybrid fiber-coaxial cable networks: practical issues in deploying residential ATM services

NASA Astrophysics Data System (ADS)

Laubach, Mark

1996-11-01

Residential broadband access network technology based on asynchronous transfer modem (ATM) will soon reach commercial availability. The capabilities provided by ATM access network promise integrated services bandwidth available in excess of those provided by traditional twisted pair copper wire public telephone networks. ATM to the side of the home placed need quality of service capability closest to the subscriber allowing immediate support for Internet services and traditional voice telephony. Other services such as desktop video teleconferencing and enhanced server-based application support can be added as part of future evolution of the network. Additionally, advanced subscriber home networks can be supported easily. This paper presents an updated summary of the standardization efforts for the ATM over HFC definition work currently taking place in the ATM forum's residential broadband working group and the standards progress in the IEEE 802.14 cable TV media access control and physical protocol working group. This update is fundamental for establishing the foundation for delivering ATM-based integrated services via a cable TV network. An economic model for deploying multi-tiered services is presenting showing that a single-tier service is insufficient for a viable cable operator business. Finally, the use of an ATM based system lends itself well to various deployment scenarios of synchronous optical networks (SONET).

IMF Control of Alfvénic Energy Transport and Deposition at High Latitudes

NASA Astrophysics Data System (ADS)

Hatch, Spencer M.; LaBelle, James; Lotko, William; Chaston, Christopher C.; Zhang, Binzheng

2017-12-01

We investigate the influence of the interplanetary magnetic field (IMF) clock angle ϕIMF on high-latitude inertial Alfvén wave (IAW) activity in the magnetosphere-ionosphere transition region using Fast Auroral SnapshoT (FAST) satellite observations. We find evidence that negative IMF Bz coincides with nightside IAW power generation and enhanced rates of IAW-associated electron energy deposition, while positive IMF Bz coincides with enhanced dayside wave and electron energy deposition. Large (≳ 5 nT) negative IMF By coincides with enhanced postnoon IAW power, while large positive IMF By coincides with enhanced but relatively weaker prenoon IAW power. For each ϕIMF orientation we compare IAW Poynting flux and IAW-associated electron energy flux distributions with previously published distributions of Alfvénic Poynting flux over ˜2-22 mHz, as well as corresponding wave-driven electron energy deposition derived from Lyon-Fedder-Mobarry global MHD simulations. We also compare IAW Poynting flux distributions with distributions of broad and diffuse electron number flux, categorized using an adaptation of the Newell et al. (2009) precipitation scheme for FAST. Under negative IMF Bz in the vicinity of the cusp (9.5-14.5 magnetic local time), regions of intense dayside IAW power correspond to enhanced diffuse electron number flux but relatively weaker broadband electron precipitation. Differences between cusp region IAW activity and broadband precipitation illustrate the need for additional information, such as fields or pitch angle measurements, to identify the physical mechanisms associated with electron precipitation in the vicinity of the cusp.

Toward noninvasive detection and monitoring of malaria with broadband diffuse optical spectroscopy

NASA Astrophysics Data System (ADS)

Campbell, Chris; Tromberg, Bruce J.; O'Sullivan, Thomas D.

2018-02-01

Despite numerous advances, malaria continues to kill nearly half a million people globally every year. New analytical methods and diagnostics are critical to understanding how treatments under development affect the lifecycle of malaria parasites. A biomarker that has been gaining interest is the "malaria pigment" hemozoin. This byproduct of hemoglobin digestion by the parasite has a unique spectral signature but is difficult to differentiate from hemoglobin and other tissue chromophores. Hemozoin can be detected in blood samples, but only utilizing approaches that require specialized training and facilities. Diffuse optical spectroscopy (DOS) is a noninvasive sensing technique that is sensitive to near-infrared absorption and scattering and capable of probing centimeter-deep volumes of tissue in vivo. DOS is relatively low-cost, does not require specialized training and thus potentially suitable for use in low-resource settings. In this work, we assess the potential of DOS to detect and quantify the presence of hemozoin noninvasively and at physiologically relevant levels. We suspended synthetic hemozoin in Intralipid-based tissue-simulating phantoms in order to mimic malaria infection in multiply-scattering tissue. Using a fiber probe that combines frequency-domain and continuous-wave broadband DOS (650-1000 nm), we detected hemozoin concentrations below 250 ng/ml, which corresponds to parasitemia sensitivities comparable to modern rapid diagnostic tests. We used the experimental variability to simulate and estimate the sensitivity of DOS to hemozoin in tissue that includes hemoglobin, water, and lipid under various tissue oxygen saturation levels. The results indicate that with increased precision, it may be possible to detect Hz noninvasively with DOS.

Towards the Internet of Smart Trains: A Review on Industrial IoT-Connected Railways.

PubMed

Fraga-Lamas, Paula; Fernández-Caramés, Tiago M; Castedo, Luis

2017-06-21

Nowadays, the railway industry is in a position where it is able to exploit the opportunities created by the IIoT (Industrial Internet of Things) and enabling communication technologies under the paradigm of Internet of Trains. This review details the evolution of communication technologies since the deployment of GSM-R, describing the main alternatives and how railway requirements, specifications and recommendations have evolved over time. The advantages of the latest generation of broadband communication systems (e.g., LTE, 5G, IEEE 802.11ad) and the emergence of Wireless Sensor Networks (WSNs) for the railway environment are also explained together with the strategic roadmap to ensure a smooth migration from GSM-R. Furthermore, this survey focuses on providing a holistic approach, identifying scenarios and architectures where railways could leverage better commercial IIoT capabilities. After reviewing the main industrial developments, short and medium-term IIoT-enabled services for smart railways are evaluated. Then, it is analyzed the latest research on predictive maintenance, smart infrastructure, advanced monitoring of assets, video surveillance systems, railway operations, Passenger and Freight Information Systems (PIS/FIS), train control systems, safety assurance, signaling systems, cyber security and energy efficiency. Overall, it can be stated that the aim of this article is to provide a detailed examination of the state-of-the-art of different technologies and services that will revolutionize the railway industry and will allow for confronting today challenges.

Towards the Internet of Smart Trains: A Review on Industrial IoT-Connected Railways

PubMed Central

Fraga-Lamas, Paula; Fernández-Caramés, Tiago M.; Castedo, Luis

2017-01-01

Nowadays, the railway industry is in a position where it is able to exploit the opportunities created by the IIoT (Industrial Internet of Things) and enabling communication technologies under the paradigm of Internet of Trains. This review details the evolution of communication technologies since the deployment of GSM-R, describing the main alternatives and how railway requirements, specifications and recommendations have evolved over time. The advantages of the latest generation of broadband communication systems (e.g., LTE, 5G, IEEE 802.11ad) and the emergence of Wireless Sensor Networks (WSNs) for the railway environment are also explained together with the strategic roadmap to ensure a smooth migration from GSM-R. Furthermore, this survey focuses on providing a holistic approach, identifying scenarios and architectures where railways could leverage better commercial IIoT capabilities. After reviewing the main industrial developments, short and medium-term IIoT-enabled services for smart railways are evaluated. Then, it is analyzed the latest research on predictive maintenance, smart infrastructure, advanced monitoring of assets, video surveillance systems, railway operations, Passenger and Freight Information Systems (PIS/FIS), train control systems, safety assurance, signaling systems, cyber security and energy efficiency. Overall, it can be stated that the aim of this article is to provide a detailed examination of the state-of-the-art of different technologies and services that will revolutionize the railway industry and will allow for confronting today challenges. PMID:28635672

Usability and Accessibility of eBay by Screen Reader

NASA Astrophysics Data System (ADS)

Buzzi, Maria Claudia; Buzzi, Marina; Leporini, Barbara; Akhter, Fahim

The evolution of Information and Communication Technology and the rapid growth of the Internet have fuelled a great diffusion of eCommerce websites. Usually these sites have complex layouts crowded with active elements, and thus are difficult to navigate via screen reader. Interactive environments should be properly designed and delivered to everyone, including the blind, who usually use screen readers to interact with their computers. In this paper we investigate the interaction of blind users with eBay, a popular eCommerce website, and discuss how using the W3C Accessible Rich Internet Applications (WAI-ARIA) suite could improve the user experience when navigating via screen reader.

A Risk Radar driven by Internet of intelligences serving for emergency management in community.

PubMed

Huang, Chongfu; Wu, Tong; Renn, Ortwin

2016-07-01

Today, most of the commercial risk radars only have the function to show risks, as same as a set of risk matrixes. In this paper, we develop the Internet of intelligences (IOI) to drive a risk radar monitoring dynamic risks for emergency management in community. An IOI scans risks in a community by 4 stages: collecting information and experience about risks; evaluating risk incidents; verifying; and showing risks. Employing the information diffusion method, we optimized to deal with the effective information for calculating risk value. Also, a specific case demonstrates the reliability and practicability of risk radar. Copyright © 2016 Elsevier Inc. All rights reserved.

Broadband near-field infrared spectromicroscopy using photothermal probes and synchrotron radiation.

PubMed

Donaldson, Paul M; Kelley, Chris S; Frogley, Mark D; Filik, Jacob; Wehbe, Katia; Cinque, Gianfelice

2016-02-08

In this paper, we experimentally demonstrate the use of infrared synchrotron radiation (IR-SR) as a broadband source for photothermal near-field infrared spectroscopy. We assess two methods of signal transduction; cantilever resonant thermal expansion and scanning thermal microscopy. By means of rapid mechanical chopping (50-150 kHz), we modulate the IR-SR at rates matching the contact resonance frequencies of atomic force microscope (AFM) cantilevers, allowing us to record interferograms yielding Fourier transform infrared (FT-IR) photothermal absorption spectra of polystyrene and cyanoacrylate films. Complementary offline measurements using a mechanically chopped CW IR laser confirmed that the resonant thermal expansion IR-SR measurements were below the diffraction limit, with a spatial resolution better than 500 nm achieved at a wavelength of 6 μm, i.e. λ/12 for the samples studied. Despite achieving the highest signal to noise so far for a scanning thermal microscopy measurement under conditions approaching near-field (dictated by thermal diffusion), the IR-SR resonant photothermal expansion FT-IR spectra measured were significantly higher in signal to noise in comparison with the scanning thermal data.

Exciton versus free carrier photogeneration in organometal trihalide perovskites probed by broadband ultrafast polarization memory dynamics.

PubMed

Sheng, ChuanXiang; Zhang, Chuang; Zhai, Yaxin; Mielczarek, Kamil; Wang, Weiwei; Ma, Wanli; Zakhidov, Anvar; Vardeny, Z Valy

2015-03-20

We studied the ultrafast transient response of photoexcitations in two hybrid organic-inorganic perovskite films used for high efficiency photovoltaic cells, namely, CH(3)NH(3)PbI(3) and CH(3)NH(3)PbI(1.1)Br(1.9) using polarized broadband pump-probe spectroscopy in the spectral range of 0.3-2.7 eV with 300 fs time resolution. For CH(3)NH(3)PbI(3) with above-gap excitation we found both photogenerated carriers and excitons, but only carriers are photogenerated with below-gap excitation. In contrast, mainly excitons are photogenerated in CH(3)NH(3)PbI(1.1)Br(1.9). Surprisingly, we also discovered in CH(3)NH(3)PbI(3), but not in CH(3)NH(3)PbI(1.1)Br(1.9), transient photoinduced polarization memory for both excitons and photocarriers, which is also reflected in the steady state photoluminescence. From the polarization memory dynamics we obtained the excitons diffusion constant in CH(3)NH(3)PbI(3), D≈0.01  cm(2) s(-1).

Exciton versus Free Carrier Photogeneration in Organometal Trihalide Perovskites Probed by Broadband Ultrafast Polarization Memory Dynamics

NASA Astrophysics Data System (ADS)

Sheng, ChuanXiang; Zhang, Chuang; Zhai, Yaxin; Mielczarek, Kamil; Wang, Weiwei; Ma, Wanli; Zakhidov, Anvar; Vardeny, Z. Valy

2015-03-01

We studied the ultrafast transient response of photoexcitations in two hybrid organic-inorganic perovskite films used for high efficiency photovoltaic cells, namely, CH3NH3PbI3 and CH3NH3PbI1.1Br1.9 using polarized broadband pump-probe spectroscopy in the spectral range of 0.3-2.7 eV with 300 fs time resolution. For CH3NH3PbI3 with above-gap excitation we found both photogenerated carriers and excitons, but only carriers are photogenerated with below-gap excitation. In contrast, mainly excitons are photogenerated in CH3NH3PbI1.1Br1.9 . Surprisingly, we also discovered in CH3NH3PbI3 , but not in CH3NH3PbI1.1Br1.9 , transient photoinduced polarization memory for both excitons and photocarriers, which is also reflected in the steady state photoluminescence. From the polarization memory dynamics we obtained the excitons diffusion constant in CH3NH3PbI3 , D ≈0.01 cm2 s-1 .

Polar Plasma Wave Investigation Data Analysis in the Extended Mission

NASA Technical Reports Server (NTRS)

Gurnett, Donald A.; Menietti, J. D.

2003-01-01

The low latitude boundary layer (LLBL) is a region where solar wind momentum and energy is transferred to the magnetosphere. Enhanced "broadband" electric plasma waves from less than 5 Hz to l0(exp 5) Hz and magnetic waves from less than 5 Hz to the electron cyclotron frequency are characteristic of the LLBL. Analyses of Polar plasma waves show that these "broadband" waves are actually discrete electrostatic and electromagnetic modes as well as solitary bipolar pulses (electron holes). It is noted that all wave modes can be generated by approx. 100 eV to approx. 10 keV auroral electrons and protons. We will review wave-particle interactions, with focus on cross- diffusion rates and the contributions of such interactions toward the formation of the boundary layer. In summary, we will present a scenario where the global solar wind-magnetosphere interaction is responsible for the auroral zone particle beams, and hence for the generation of plasma waves and the formation of the boundary layer. It is speculated that all planetary magnetospheres will have boundary layers and they will be characterized by similar currents and plasma wave modes.

Polar Plasma Wave Investigation Data Analysis in the Extended Mission

NASA Technical Reports Server (NTRS)

Gurnett, Donald A.

2004-01-01

The low latitude boundary layer (LLBL) is a region where solar wind momentum and energy is transferred to the magnetosphere. Enhanced "broadband" electric plasma waves from less than 5 Hz to 10(exp 5) Hz and magnetic waves from less than 5 Hz to the electron cyclotron frequency are characteristic of the LLBL. Analyses of Polar plasma waves show that these "broadband" waves are actually discrete electrostatic and electromagnetic modes as well as solitary bipolar pulses (electron holes). It is noted that all wave modes can be generated by approx. 100 eV to approx. 10 keV auroral electrons and protons. We will review wave-particle interactions, with focus on cross-diffusion rates and the contributions of such interactions toward the formation of the boundary layer. In summary, we will present a scenario where the global solar wind-magnetosphere interaction is responsible for the auroral zone particle beams, and hence for the generation of plasma waves and the formation of the boundary layer. It is speculated that all planetary magnetospheres will have boundary layers and they will be characterized by similar currents and plasma wave modes.

BLUECOM+ project: Connecting Humans and Systems at Ocean Remote Areas using Cost-effective Broadband Communications field

NASA Astrophysics Data System (ADS)

Brito, Pedro; Terrinha, Pedro; Magalhães, Vitor; Santos, Joana; Duarte, Débora; Campos, Rui

2017-04-01

The BLUECOM + project (Connecting Humans and Systems at Remote Ocean Areas using Cost-effective Broadband Communications) aims at developing an innovative communications solution that will enable broadband, cost-effective Internet access in remote ocean areas (ideally beyond 100 km from shore), using standard wireless access technologies - e.g., Wi-Fi and LTE. BLUECOM+ is an EEA Grants PT02 project developed by INESC TEC (Institute for Systems and Computer Engineering, Technology and Science), IPMA (Portuguese Institute for the Sea and the Atmosphere), and MARLO (Transport and Logistics Consultants). The BLUECOM+ key idea and innovation lies on deploying a long-term communications infrastructure, which will extend broadband communications from shore to remote ocean areas by leveraging (1) Helikites - a combination of a helium balloon and kite - that can be tethered to existing or new land and ocean platforms, (2) long range line of sight wireless communications using TV white spaces, and (3) multi-hop relaying techniques to further increase range. At this stage the communications protocols were defined and tested in lab conditions and two sea trials for demonstration of the system were carried out in July/2016 and September/2016 using research vessels. Results of the cruises: 1st cruise corresponded to the first sea-trials of the project. Single-hop communications were established between a land base station deployed at Cabo Espichel lighthouse and the Sea Station deployed in a Helikite launched from the vessel and flying at an altitude of 120m. Successful communications between the two stations were established at a maximum distance of 40km with a data rate in excess of 1Mbit/s. 2nd cruise corresponded to the second sea-trials. During this trial single-hop and two-hop land-sea communications were tested. For two-hop communications tests two Helikites were launched at 120m from two vessels. The first was launched from a vessel closer to shore; the other was launched from the second vessel and connected to the first to have Internet access. The tests were performed at increasing distances up to a maximum distance of 45km from the land station and the first hop, and up to 10km between the two Helikites. The main results achieved were: • Single-hop data rates in excess of 1Mbit/s up to 45km; • Two-hop data rates in excess of 500kbit/s up to 55km; • Video conference with land at 42km offshore without a glitch; • Real-time upload of data collected by an autonomous vehicle offshore to the cloud. A 3rd cruise will be done this year to test video streaming to shore of sea bottom images acquired from the ship with a drop down video system. This will include the integration of the BLUECOM+ network with the drop down video system, in order to demonstrate real-time underwater video transmission offshore. Acknowledgements: This work was developed as part of the BLUECOM+ project (PT02_Aviso4_0005) funded by the EEA Grants and Norway Grants.

Rumor Diffusion and Convergence during the 3.11 Earthquake: A Twitter Case Study

PubMed Central

Takayasu, Misako; Sato, Kazuya; Sano, Yukie; Yamada, Kenta; Miura, Wataru; Takayasu, Hideki

2015-01-01

We focus on Internet rumors and present an empirical analysis and simulation results of their diffusion and convergence during emergencies. In particular, we study one rumor that appeared in the immediate aftermath of the Great East Japan Earthquake on March 11, 2011, which later turned out to be misinformation. By investigating whole Japanese tweets that were sent one week after the quake, we show that one correction tweet, which originated from a city hall account, diffused enormously. We also demonstrate a stochastic agent-based model, which is inspired by contagion model of epidemics SIR, can reproduce observed rumor dynamics. Our model can estimate the rumor infection rate as well as the number of people who still believe in the rumor that cannot be observed directly. For applications, rumor diffusion sizes can be estimated in various scenarios by combining our model with the real data. PMID:25831122

TeleMEDiana: telesurgery and telemedicine by satellite and the Internet

NASA Astrophysics Data System (ADS)

Dobrosavljevic, Sneja; Welter, Roger

2002-08-01

The rapid development of technology and its integration into the spectrum of medical care are creating a pressing need for healthcare professionals to continuously update their knowledge and skills. In view of these needs the European Association of Visceral Surgery (AECV) which had been a platform for medical congresses in Luxembourg (1988, 1992, 1995, 1998) has developed TeleMEDiana a new broadband communication service introducing standards of excellence in Continuous Medical Education.TeleMEDiana broadcast a daily program with pedagogically enhanced video content in a number of therapeutic areas to MD's, professors and students in hospitals, universities and research centers. The educational programs are provided by leading European hospitals which have joined the TeleMEDiana Scientific Network TSN. The scientific integrity is certified by an international committee composed of recognized pioneers. Committed to deliver high resolution video streaming, TeleMEDiana has set up and successfully tested a new platform built on secure and cost-efficient satellite operator SES-ASTRA complemented by the Internet and can deliver programs to any workplace equipped with satellite dishes and high-quality set-top boxes. Telemediana offers herewith an optimal collaboration and dissemination platform to decisive players involved in Continuing Medical Education.

Improving Family Communication.

PubMed

Medrano, Vilma; Bonilla, Gladys; Hernández, Ericka; Romanjek, Mariana Harnecker; Gómez, Adriana; Hernández, Jasón; Reyes, Marcela Ríos; Lindenberg, Cathy Strachan

2017-03-01

TeenSmart International harnesses the power and flexibility of technology to empower youth to take personal responsibility for their health and lifestyle choices. Access to the Internet via mobile phones is often cheaper than paying to connect to a wired broadband service, and in rural areas, mobile networks may be the only means of accessing the Internet. This study assessed the feasibility, acceptability, and impact of "cues to action" or brief motivating cell phone text messages to improve adolescent family communication and relationships. A quasi-experimental design using a voluntary sample of 100 Nicaraguan youth at high risk for poor family communication participated. Pre- and posttest quantitative measures using Student t statistical analysis, a focus group, and a participant testimony provided the evaluation evidence. Findings suggest that there are economic and motivational barriers to the use of text messages, but when barriers are eliminated, the behavioral results are positive. Youth who received two weekly text messages over a 6-month period demonstrated statistically significant improvements in family communication perceptions, attitudes, and behaviors, strengthening their family communications and relationships. Brief and personalized text messaging "cues to action" may be a cost-effective intervention to improve adolescent healthy lifestyle behaviors.

Cloud Based Drive Forensic and DDoS Analysis on Seafile as Case Study

NASA Astrophysics Data System (ADS)

Bahaweres, R. B.; Santo, N. B.; Ningsih, A. S.

2017-01-01

The rapid development of Internet due to increasing data rates through both broadband cable networks and 4G wireless mobile, make everyone easily connected to the internet. Storages as Services (StaaS) is more popular and many users want to store their data in one place so that whenever they need they can easily access anywhere, any place and anytime in the cloud. The use of the service makes it vulnerable to use by someone to commit a crime or can do Denial of Service (DoS) on cloud storage services. The criminals can use the cloud storage services to store, upload and download illegal file or document to the cloud storage. In this study, we try to implement a private cloud storage using Seafile on Raspberry Pi and perform simulations in Local Area Network and Wi-Fi environment to analyze forensically to discover or open a criminal act can be traced and proved forensically. Also, we can identify, collect and analyze the artifact of server and client, such as a registry of the desktop client, the file system, the log of seafile, the cache of the browser, and database forensic.

Artificial neural networks for retrieving absorption and reduced scattering spectra from frequency-domain diffuse reflectance spectroscopy at short source-detector separation

PubMed Central

Chen, Yu-Wen; Chen, Chien-Chih; Huang, Po-Jung; Tseng, Sheng-Hao

2016-01-01

Diffuse reflectance spectroscopy (DRS) based on the frequency-domain (FD) technique has been employed to investigate the optical properties of deep tissues such as breast and brain using source to detector separation up to 40 mm. Due to the modeling and system limitations, efficient and precise determination of turbid sample optical properties from the FD diffuse reflectance acquired at a source-detector separation (SDS) of around 1 mm has not been demonstrated. In this study, we revealed that at SDS of 1 mm, acquiring FD diffuse reflectance at multiple frequencies is necessary for alleviating the influence of inevitable measurement uncertainty on the optical property recovery accuracy. Furthermore, we developed artificial neural networks (ANNs) trained by Monte Carlo simulation generated databases that were capable of efficiently determining FD reflectance at multiple frequencies. The ANNs could work in conjunction with a least-square optimization algorithm to rapidly (within 1 second), accurately (within 10%) quantify the sample optical properties from FD reflectance measured at SDS of 1 mm. In addition, we demonstrated that incorporating the steady-state apparatus into the FD DRS system with 1 mm SDS would enable obtaining broadband absorption and reduced scattering spectra of turbid samples in the wavelength range from 650 to 1000 nm. PMID:27446671

Strategic Reflection on the Use of eLearning Freeware Tools in Higher Education

ERIC Educational Resources Information Center

Gaviola Feck, Dolores

2016-01-01

People are self-learning on the Internet and the various eLearning freeware tools of the 21st century diffuses a whole new pedagogy; yet, generational trends from organizations, corporations, and academic institutions minimally show implementation of various blended learning approaches online into their organizational culture and climate. The…

Ethnography, the Internet, and Youth Culture: Strategies for Examining Social Resistance and "Online-Offline" Relationships

ERIC Educational Resources Information Center

Wilson, Brian

2006-01-01

The integration of traditional (offline and face-to-face) and virtual ethnographic methods can aid researchers interested in developing understandings of relationships between online and offline cultural life, and examining the diffuse and sometimes global character of youth resistance. In constructing this argument, I have used insights from…

Schooling Attainment's Influence on Internet Adoption: Education's Role in the Cross-National Development of the Mass-Media Knowledge Gap

ERIC Educational Resources Information Center

Mann, Bryan A.; Smith, William C.; Baker, David P.

2016-01-01

Research about innovation adoption underplays the role of educational attainment in the individual consumption of technology; consequently, past research underestimates the importance education plays independent of wealth in diffusion, particularly as absolute levels of formal education rise worldwide. Using data from the Programme for…

Ponzi scheme diffusion in complex networks

NASA Astrophysics Data System (ADS)

Zhu, Anding; Fu, Peihua; Zhang, Qinghe; Chen, Zhenyue

2017-08-01

Ponzi schemes taking the form of Internet-based financial schemes have been negatively affecting China's economy for the last two years. Because there is currently a lack of modeling research on Ponzi scheme diffusion within social networks yet, we develop a potential-investor-divestor (PID) model to investigate the diffusion dynamics of Ponzi scheme in both homogeneous and inhomogeneous networks. Our simulation study of artificial and real Facebook social networks shows that the structure of investor networks does indeed affect the characteristics of dynamics. Both the average degree of distribution and the power-law degree of distribution will reduce the spreading critical threshold and will speed up the rate of diffusion. A high speed of diffusion is the key to alleviating the interest burden and improving the financial outcomes for the Ponzi scheme operator. The zero-crossing point of fund flux function we introduce proves to be a feasible index for reflecting the fast-worsening situation of fiscal instability and predicting the forthcoming collapse. The faster the scheme diffuses, the higher a peak it will reach and the sooner it will collapse. We should keep a vigilant eye on the harm of Ponzi scheme diffusion through modern social networks.

Characterization of water molecular state in in-vivo thick tissues using diffuse optical spectroscopic imaging

NASA Astrophysics Data System (ADS)

Chung, So Hyun

Structural changes in water molecules are related to physiological, anatomical and pathological properties of tissues. Near infrared (NIR) optical absorption methods are sensitive to water; however, detailed characterization of water in thick tissues is difficult to achieve because subtle spectral shifts can be obscured by multiple light scattering. In the NIR, a water absorption peak is observed around 975 nm. The precise NIR peak's shape and position are highly sensitive to water molecular disposition. A bound water index (BWI) was developed that quantifies the spectral shift and shape changes observed in tissue water absorption spectra measured by broadband diffuse optical spectroscopic imaging (DOSI). DOSI quantitatively measures light absorption and scattering spectra in cm-deep tissues and therefore reveals bound water spectral shifts. BWI as a water state index was validated by comparing broadband DOSI to MRI and a conductivity cell using bound water phantoms. Non-invasive BWI measurements of malignant and normal tissues in 18 subjects showed a significantly higher fraction of free water in malignant tissues (p<0.0001) compared to normal tissues. BWI showed potential as a prognostic index based on high correlations with tumor grade and size. An algorithm for absolute temperature measurements in deep tissues was developed based on resolving opposing effects of water vibrational frequency shifts due to macromolecular binding. DOSI measures absolute temperature with a difference of 1.1+/-0.91°C from a thermistor. Deep tissue temperature measured in forearms during cold-stress was consistent with previously reported invasively-measured deep tissue temperature. Finally, the BWI was compared to Apparent Diffusion Coefficient (ADC) of diffusion weighted MRI in 9 breast cancer patients. The BWI and ADC correlated (R=0.8, p=<0.01) and both parameters decreased with increasing bulk water content in cancer tissues. Although BWI and ADC are positively correlated in vivo, BWI appears to be more sensitive to free water in the extracellular matrix while ADC reflects increased tumor cellularity. The relationship between ADC, BWI and bulk water concentration suggests that both parameters have potential for assessing tumor histopathological grade. My results confirm the importance of water as a critical tissue component that can potentially provide unique insight into the molecular pathophysiology of cancer.

Do lessons learned in a training intervention on web-based health care resources diffuse to nonexposed members in the primary care setting? A comparative study.

PubMed

Homa, Karen; Schifferdecker, Karen E; Reed, Virginia A

2008-01-01

The Internet offers a significant information resource for health professionals. A strategy to improve the use of these resources is for health care providers and staff to receive specific training. The aim of this study was to determine whether those who attended an Internet health care resource training intervention transferred knowledge and skills to others in the practice. Twenty-four primary care practices participated in the study in which 64 providers and staff attended a training intervention and 288 did not. A preintervention questionnaire that assessed knowledge, skill, and Internet usage was compared with a postintervention questionnaire. The main effect of interest in the linear model was the group by time interaction term, to determine whether knowledge and skill improved for both groups. There were 41 attendees and 222 nonattendees that completed both pre- and postintervention questionnaires. There were 9 variables that showed a possible diffusion pattern, in which both attendees and nonattendees improved between pre- and postintervention. Overall, the training intervention seemed to have impacted knowledge and skills of the respondents and also reported improvements in the clinical area of patient education, but frequency of use for most Web resources for medical decision making did not improve. An improvement strategy that depends on a training intervention for a few members in a practice may not necessarily transfer relative to all aspects of patient care.

Do Lessons Learned in a Training Intervention on Web-Based Health Care Resources Diffuse to Nonexposed Members in the Primary Care Setting? A Comparative Study

PubMed Central

Homa, Karen; Schifferdecker, Karen E.; Reed, Virginia A.

2009-01-01

Objective The Internet offers a significant information resource for health professionals. A strategy to improve the use of these resources is for health care providers and staff to receive specific training. The aim of this study was to determine whether those who attended an Internet health care resource training intervention transferred knowledge and skills to others in the practice. Methods Twenty-four primary care practices participated in the study in which 64 providers and staff attended a training intervention and 288 did not. A preintervention questionnaire that assessed knowledge, skill, and Internet usage was compared with a postintervention questionnaire. The main effect of interest in the linear model was the group by time interaction term, to determine whether knowledge and skill improved for both groups. Results There were 41 attendees and 222 nonattendees that completed both pre- and postintervention questionnaires. There were 9 variables that showed a possible diffusion pattern, in which both attendees and nonattendees improved between pre- and postintervention. Overall, the training intervention seemed to have impacted knowledge and skills of the respondents and also reported improvements in the clinical area of patient education, but frequency of use for most Web resources for medical decision making did not improve. Conclusion An improvement strategy that depends on a training intervention for a few members in a practice may not necessarily transfer relative to all aspects of patient care. PMID:19020403

Comparative Study of Broadband Photometry Relations for Ultra-Diffuse and Normal Galaxies in the Coma Cluster

NASA Astrophysics Data System (ADS)

Stone, Maria Babakhanyan

Ultra-diffuse galaxies are a novel type of galaxies discovered first in the Coma cluster. These objects are characterized simultaneously by large sizes and by very low counts of constituent stars. Conflicting theories have been proposed to explain how these large diffuse galaxies could have survived in the harsh environment of clusters. To date, thousands of these new galaxies have been identified in cluster environments. However, further studies are required to understand their relationship to the known giant and dwarf classes of galaxies. The purpose of this study is to compare the trends of inner and outer populations of normal members of the Coma cluster and ultra-diffuse galaxies in color-magnitude space. The present work used several astronomical catalogs to identify the member galaxies based on the coordinates of their positions and to extract available colors and magnitudes. We obtained correlations to convert colors and magnitudes from different systems into the common Sloan Digital Sky Survey system to facilitate the comparative analysis. We showed the quantitative relations describing the color-magnitude trends of galaxies in the core and the outskirts of the cluster. We confirmed that the inner and outer populations of ultra-diffuse galaxies exhibit an offset similar to the normal red sequence galaxies. We presented an initial assessment of stellar population ages and metallicities which correspond to the obtained color offsets. We surveyed the available images of the cluster for outliers, merger candidates, and candidate ultra-diffuse galaxies. We conclude that ultra-diffuse galaxies are an important part of the Coma cluster evolutionary history and future work is needed especially in obtaining spectroscopic data of a larger number of these dim galaxies.

Barriers and Facilitators to Home Computer and Internet Use Among Urban Novice Computer Users of Low Socioeconomic Position

PubMed Central

Bennett, Gary G; Viswanath, K

2007-01-01

Background Despite the increasing penetration of the Internet and amount of online health information, there are significant barriers that limit its widespread adoption as a source of health information. One is the “digital divide,” with people of higher socioeconomic position (SEP) demonstrating greater access and usage compared to those from lower SEP groups. However, as the access gap narrows over time and more people use the Internet, a shift in research needs to occur to explore how one might improve Internet use as well as website design for a range of audiences. This is particularly important in the case of novice users who may not have the technical skills, experience, or social connections that could help them search for health information using the Internet. The focus of our research is to investigate the challenges in the implementation of a project to improve health information seeking among low SEP groups. The goal of the project is not to promote health information seeking as much as to understand the barriers and facilitators to computer and Internet use, beyond access, among members of lower SEP groups in an urban setting. Objective The purpose was to qualitatively describe participants’ self-identified barriers and facilitators to computer and Internet use during a 1-year pilot study as well as the challenges encountered by the research team in the delivery of the intervention. Methods Between August and November 2005, 12 low-SEP urban individuals with no or limited computer and Internet experience were recruited through a snowball sampling. Each participant received a free computer system, broadband Internet access, monthly computer training courses, and technical support for 1 year as the intervention condition. Upon completion of the study, participants were offered the opportunity to complete an in-depth semistructured interview. Interviews were approximately 1 hour in length and were conducted by the project director. The interviews were held in the participants’ homes and were tape recorded for accuracy. Nine of the 12 study participants completed the semistructured interviews. Members of the research team conducted a qualitative analysis based on the transcripts from the nine interviews using the crystallization/immersion method. Results Nine of the 12 participants completed the in-depth interview (75% overall response rate), with three men and six women agreeing to be interviewed. Major barriers to Internet use that were mentioned included time constraints and family conflict over computer usage. The monthly training classes and technical assistance components of the intervention surfaced as the most important facilitators to computer and Internet use. The concept of received social support from other study members, such as assistance with computer-related questions, also emerged as an important facilitator to overall computer usage. Conclusions This pilot study offers important insights into the self-identified barriers and facilitators in computer and Internet use among urban low-SEP novice users as well as the challenges faced by the research team in implementing the intervention. PMID:17951215

Progress Toward Standards for the Seamless Interoperability of Broadband Satellite Communication Networks

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Glover, Daniel R.; vonDeak, Thomas C.; Bhasin, Kul B.

1998-01-01

The realization of the full potential of the National Information Infrastructure (NH) and Global Information Infrastructure (GII) requires seamless interoperability of emerging satellite networks with terrestrial networks. This requires a cooperative effort between industry, academia and government agencies to develop and advocate new, satellite-friendly communication protocols and modifications to existing communication protocol standards. These groups have recently come together to actively participating in a number of standards making bodies including: the Internet Engineering Task Force (IETF), the Asynchronous Transfer Mode (ATM) Forum, the International Telecommunication Union (ITU) and the Telecommunication Industry Association MA) to ensure that issues regarding efficient use of these protocols over satellite links are not overlooked. This paper will summarize the progress made toward standards development to achieve seamless integration and accelerate the deployment of multimedia applications.

A Distributed Cache Update Deployment Strategy in CDN

NASA Astrophysics Data System (ADS)

E, Xinhua; Zhu, Binjie

2018-04-01

The CDN management system distributes content objects to the edge of the internet to achieve the user's near access. Cache strategy is an important problem in network content distribution. A cache strategy was designed in which the content effective diffusion in the cache group, so more content was storage in the cache, and it improved the group hit rate.

The Strength of Weak Ties in Electronic Development of the Scholarly Communication System.

ERIC Educational Resources Information Center

Schwartz, Charles A.

1994-01-01

Three overlapping models of new technology diffusion are described in relation to the Internet: (1) individual threshold; (2) critical mass; and (3) strength of weak ties. The prospective role of academic libraries in the electronic development of the scholarly communication system is discussed, and further research is suggested. (55 references)…

Malaysia's Multimedia Super Corridor and Roles of Information Professionals.

ERIC Educational Resources Information Center

Reid, Edna

In Malaysia, the government is supporting the diffusion of the Internet and is spearheading a project to bring Malaysia into the information age, by helping to design a smart city called the Multimedia Super Corridor (MSC). The MSC is being planned as a high-technology center where world-class multimedia companies can develop state-of-the-art…

Dynamic nonrobotic telemicroscopy via skype: A cost effective solution to teleconsultation.

PubMed

Sirintrapun, Sahussapont J; Cimic, Adela

2012-01-01

Skype is a peer to peer software application that has been historically used for voice and video calls, instant messaging, and file transfer over the Internet. Few studies are available using Skype specifically for telepathology. Our aim is to show that dynamic nonrobotic teleconsultation is possible and even effective via means of a standard microscope camera capable of live acquisition, Skype, an established broad band internet connection, and experienced pathologists. Both the consulting "sending" pathologist and consultant "receiving" pathologist are reasonably experienced general surgical pathologists at junior attending level with several years of experience in sign out. Forty-five cases were chosen encompassing a broad range of surgical pathology specimens. The cases were prospectively evaluated with the consultant diagnosis used as a preliminary pathologic impression with the final diagnosis being confirmation. Versions of Skype 5.0 and above were used along with established broadband internet connections, usually between academic medical institutions. Forty of forty-five cases (89%) were essentially concordant. In four of forty-five cases (9%), the consulting impression gave a differential, but favored an entity which did not match the final diagnosis. Only one case (2%) did the consulting impression not match the final diagnosis; a discordant opinion. The image quality via Skype screen sharing option is excellent. Essentially no lag time was seen. We have shown in our small pilot study that Skype is an effective cost-efficient means for teleconsultation, particularly in the setting of entity-related differential diagnoses in surgical pathology and when both the consulting and consultant pathologists are reasonably experienced.

Implementing eco friendly highly reliable upload feature using multi 3G service

NASA Astrophysics Data System (ADS)

Tanutama, Lukas; Wijaya, Rico

2017-12-01

The current trend of eco friendly Internet access is preferred. In this research the understanding of eco friendly is minimum power consumption. The devices that are selected have operationally low power consumption and normally have no power consumption as they are hibernating during idle state. To have the reliability a router of a router that has internal load balancing feature will provide the improvement of previous research on multi 3G services for broadband lines. Previous studies emphasized on accessing and downloading information files from Public Cloud residing Web Servers. The demand is not only for speed but high reliability of access as well. High reliability will mean mitigating both direct and indirect high cost due to repeated attempts of uploading and downloading the large files. Nomadic and mobile computer users need viable solution. Following solution for downloading information has been proposed and tested. The solution is promising. The result is now extended to providing reliable access line by means of redundancy and automatic reconfiguration for uploading and downloading large information files to a Web Server in the Cloud. The technique is taking advantage of internal load balancing feature to provision a redundant line acting as a backup line. A router that has the ability to provide load balancing to several WAN lines is chosen. The WAN lines are constructed using multiple 3G lines. The router supports the accessing Internet with more than one 3G access line which increases the reliability and availability of the Internet access as the second line immediately takes over if the first line is disturbed.

Advanced payload concepts and system architecture for emerging services in Indian National Satellite Systems

NASA Astrophysics Data System (ADS)

Balasubramanian, E. P.; Rao, N. Prahlad; Sarkar, S.; Singh, D. K.

2008-07-01

Over the past two decades Indian Space Research Organization (ISRO) has developed and operationalized satellites to generate a large capacity of transponders for telecommunication service use in INSAT system. More powerful on-board transmitters are built to usher-in direct-to-home broadcast services. These have transformed the Satcom application scenario in the country. With the proliferation of satellite technology, a shift in the Indian market is witnessed today in terms of demand for new services like Broadband Internet, Interactive Multimedia, etc. While it is imperative to pay attention to market trends, ISRO is also committed towards taking the benefits of technological advancement to all round growth of our population, 70% of which dwell in rural areas. The initiatives already taken in space application related to telemedicine, tele-education and Village Resource Centres are required to be taken to a greater height of efficiency. These targets pose technological challenges to build a large capacity and cost-effective satellite system. This paper addresses advanced payload concepts and system architecture along with the trade-off analysis on design parameters in proposing a new generation satellite system capable of extending the reach of the Indian broadband structure to individual users, educational and medical institutions and enterprises for interactive services. This will be a strategic step in the evolution of INSAT system to employ advanced technology to touch every human face of our population.

Modern techniques and technologies for unbundled access in the local loop

NASA Astrophysics Data System (ADS)

Bacis Vasile, Irina Bristena; Schiopu, Paul; Marghescu, Cristina

2015-02-01

The efficient and unbundled use of the existing telecommunications infrastructure represents a major goal for the development of the services offered by telecommunications providers. A major telecommunications operator can provide services to a subscriber using a copper wire pair or part of the frequency spectrum of a copper wire pair, together with other operators, through a process of unbundling access in the local loop. Since access to the vocal band is an already solved problem, concerns turn to the broadband access with xDSL service delivery on ungrouped subscriber loops; besides the legal and economic aspects involved this has become an engineering problem also. The local loop unbundling methods have a substantial technical impact. This impact should be taken into account right from the design stage and then in the standardization stage of broadband systems intended to operate on copper wire pairs in the local loop. These systems are known under the generic term of xDSL and began to be analyzed in the late 90s. xDSL became the dominant solution for providing Internet at a reasonable price for both residential and business subscribers. In this massive development scenario, certain problems will arise from the early stages of deployment, and another type of problems will occur later on when a large number of systems will be installed in a single beam.

Microstructure abnormalities in adolescents with internet addiction disorder.

PubMed

Yuan, Kai; Qin, Wei; Wang, Guihong; Zeng, Fang; Zhao, Liyan; Yang, Xuejuan; Liu, Peng; Liu, Jixin; Sun, Jinbo; von Deneen, Karen M; Gong, Qiyong; Liu, Yijun; Tian, Jie

2011-01-01

Recent studies suggest that internet addiction disorder (IAD) is associated with structural abnormalities in brain gray matter. However, few studies have investigated the effects of internet addiction on the microstructural integrity of major neuronal fiber pathways, and almost no studies have assessed the microstructural changes with the duration of internet addiction. We investigated the morphology of the brain in adolescents with IAD (N = 18) using an optimized voxel-based morphometry (VBM) technique, and studied the white matter fractional anisotropy (FA) changes using the diffusion tensor imaging (DTI) method, linking these brain structural measures to the duration of IAD. We provided evidences demonstrating the multiple structural changes of the brain in IAD subjects. VBM results indicated the decreased gray matter volume in the bilateral dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the orbitofrontal cortex (OFC), the cerebellum and the left rostral ACC (rACC). DTI analysis revealed the enhanced FA value of the left posterior limb of the internal capsule (PLIC) and reduced FA value in the white matter within the right parahippocampal gyrus (PHG). Gray matter volumes of the DLPFC, rACC, SMA, and white matter FA changes of the PLIC were significantly correlated with the duration of internet addiction in the adolescents with IAD. Our results suggested that long-term internet addiction would result in brain structural alterations, which probably contributed to chronic dysfunction in subjects with IAD. The current study may shed further light on the potential brain effects of IAD.

Core-based intrinsic fiber-optic absorption sensor for the detection of volatile organic compounds

NASA Astrophysics Data System (ADS)

Klunder, Gregory L.; Russo, Richard E.

1995-03-01

A core-based intrinsic fiber-optic absorption sensor has been developed and tested for the detection of volatile organic compounds. The distal ends of transmitting and receiving fibers are connected by a small cylindrical section of an optically clear silicone rubber. The silicone rubber acts both as a light pipe and as a selective membrane into which the analyte molecules can diffuse. The sensor has been used to detect volatile organics (trichloroethylene, 1,1-dichloroethylene, and benzene) in both aqueous solutions and in the vapor phase or headspace. Absorption spectra obtained in the near-infrared (near-IR) provide qualitative and quantitative information about the analyte. Water, which has strong broad-band absorption in the near-IR, is excluded from the spectra because of the hydrophobic properties of the silicone rubber. The rate-limiting step is shown to be the diffusion through the Nernstian boundary layer surrounding the sensor and not the diffusion through the silicone polymer. The rate of analyte diffusion into the sensor, as measured by the t(sub 90) values (the time required for the sensor to reach 90% of the equilibrium value), is 30 min for measurements in aqueous solutions and approximately 3 min for measurements made in the headspace. The limit of detection obtained with this sensor is approximately 1.1 ppm for trichloroethylene in an aqueous solution.

How Do Adolescents Access Health Information? And Do They Ask Their Physicians?

PubMed Central

Ettel, George; Nathanson, Ian; Ettel, Donna; Wilson, Christine; Meola, Paul

2012-01-01

Objective: To improve understanding about how high school students use electronic tools to obtain health information and how this information affects their behavior. Design/Methods: Using a cross-sectional design, we administered an anonymous survey to high school students in grades 9 through 12 at a single private Catholic high school, inquiring about their use of electronic tools to obtain health information, topics of interest, sources used to obtain information, and modifications in their behavior based on that information. Descriptive statistics and multivariate analysis of variance were used to compare trends across grade levels. Results: Of 705 students enrolled, 24.7% were either absent or chose not to participate in the survey. Of the remaining 531 students, 497 completed the surveys, for a response rate of 70.5% (497 of 705) and a participation rate of 93.6% (497 of 531). All students were comfortable using the Internet, and >90% used it at home and in school. Access to broadband applications averaged 95% at home and 80% at school. A significant proportion (0.66; p < 0.0001) of students reported that they trusted the information found online, and 22% (not significant) modified their behavior on the basis of the information they found. Forty-two percent searched for general health information, and 43% investigated specific medical conditions or disease states. Topics related to skin were researched significantly more than nutrition, birth control, and sexually transmitted diseases. Although a significant number of students (p < 0.05) reported conducting e-mail conversations related to health topics with their teachers, <5% had e-mail communications with physicians. Conclusions: These data indicate that most high school students used the Internet and broadband applications at school and at home as resources for health care information. A significant number of students trusted the online information, and at nearly one-quarter subsequently modified their behavior. Students conducted e-mail conversations with teachers about health-related topics, but few students used this tool to communicate with their physicians. This information raises questions about design and implementation of strategies to provide adolescents access to appropriate health care information, including that provided by physicians. PMID:22529757

The Northwest Indiana Robotic Telescope

NASA Astrophysics Data System (ADS)

Slavin, Shawn D.; Rengstorf, A. W.; Aros, J. C.; Segally, W. B.

2011-01-01

The Northwest Indiana Robotic (NIRo) Telescope is a remote, automated observing facility recently built by Purdue University Calumet (PUC) at a site in Lowell, IN, approximately 30 miles from the PUC campus. The recently dedicated observatory will be used for broadband and narrowband optical observations by PUC students and faculty, as well as pre-college students through the implementation of standards-based, middle-school modules developed by PUC astronomers and education faculty. The NIRo observatory and its web portal are the central technical elements of a project to improve astronomy education at Purdue Calumet and, more broadly, to improve science education in middle schools of the surrounding region. The NIRo Telescope is a 0.5-meter (20-inch) Ritchey-Chrétien design on a Paramount ME robotic mount, featuring a seven-position filter wheel (UBVRI, Hα, Clear), Peltier (thermoelectrically) cooled CCD camera with 3056 x 3056, square, 12 μm pixels, and off-axis guiding. It provides a coma-free imaging field of 0.5 degrees square, with a plate scale of 0.6 arcseconds per pixel. The observatory has a wireless internet connection, local weather station which publishes data to an internet weather site, and a suite of CCTV security cameras on an IP-based, networked video server. Control of power to every piece of instrumentation is maintained via internet-accessible power distribution units. The telescope can be controlled on-site, or off-site in an attended fashion via an internet connection, but will be used primarily in an unattended mode of automated observation, where queued observations will be scheduled daily from a database of requests. Completed observational data from queued operation will be stored on a campus-based server, which also runs the web portal and observation database. Partial support for this work was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No. 0736592.

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

NASA Astrophysics Data System (ADS)

Khan, Mohammed Zahed Mustafa; Ng, Tien Khee; Ooi, Boon S.

2014-11-01

The advances in lasers, electronic and photonic integrated circuits (EPIC), optical interconnects as well as the modulation techniques allow the present day society to embrace the convenience of broadband, high speed internet and mobile network connectivity. However, the steep increase in energy demand and bandwidth requirement calls for further innovation in ultra-compact EPIC technologies. In the optical domain, advancement in the laser technologies beyond the current quantum well (Qwell) based laser technologies are already taking place and presenting very promising results. Homogeneously grown quantum dot (Qdot) lasers and optical amplifiers, can serve in the future energy saving information and communication technologies (ICT) as the work-horse for transmitting and amplifying information through optical fiber. The encouraging results in the zero-dimensional (0D) structures emitting at 980 nm, in the form of vertical cavity surface emitting laser (VCSEL), are already operational at low threshold current density and capable of 40 Gbps error-free transmission at 108 fJ/bit. Subsequent achievements for lasers and amplifiers operating in the O-, C-, L-, U-bands, and beyond will eventually lay the foundation for green ICT. On the hand, the inhomogeneously grown quasi 0D quantum dash (Qdash) lasers are brilliant solutions for potential broadband connectivity in server farms or access network. A single broadband Qdash laser operating in the stimulated emission mode can replace tens of discrete narrow-band lasers in dense wavelength division multiplexing (DWDM) transmission thereby further saving energy, cost and footprint. We herein reviewed the1 progress of both Qdots and Qdash devices, based on the InAs/InGaAlAs/InP and InAs/InGaAsP/InP material systems, from the angles of growth and device performance. In particular, we discussed the progress in lasers, semiconductor optical amplifiers (SOA), mode locked lasers, and superluminescent diodes, which are the building blocks of EPIC and ICT. Alternatively, these optical sources are potential candidates for other multi-disciplinary field applications.

Tunable Dielectric Materials and Devices for Broadband Wireless Communications

NASA Technical Reports Server (NTRS)

Mueller, Carl H.; Miranda, Felix A.; Dayton, James A. (Technical Monitor)

1998-01-01

Wireless and satellite communications are a rapidly growing industries which are slated for explosive growth into emerging countries as well as countries with advanced economies. The dominant trend in wireless communication systems is towards broadband applications such as multimedia file transfer, video transmission and Internet access. These applications require much higher data transmission rates than those currently used for voice transmission applications. To achieve these higher data rates, substantially larger bandwidths and higher carrier frequencies are required. A key roadblock to implementing these systems at K-band (18-26.5 GHz) and Ka-band (26.5-40 GHz) is the need to develop hardware which meets the requirements for high data rate transmission in a cost effective manner. In this chapter, we report on the status of tunable dielectric thin films for devices, such as resonators, filters, phased array antennas, and tunable oscillators, which utilize nonlinear tuning in the control elements. Paraelectric materials such as Barium Strontium Titanate ((Ba, Sr)TiO3) have dielectric constants which can be tuned by varying the magnitude of the electric field across the material. Therefore, these materials can be used to control the frequency and/or phase response of various devices such as electronically steerable phased array antennas, oscillators, and filters. Currently, tunable dielectric devices are being developed for applications which require high tunability, low loss, and good RF power-handling capabilities at microwave and millimeter-wave frequencies. These properties are strongly impacted by film microstructure and device design, and considerable developmental work is still required. However, in the last several years enormous progress has occurred in this field, validating the potential of tunable dielectric technology for broadband wireless communication applications. In this chapter we summarize how film processing techniques, microwave test configurations, and prototype devices have combined to drive the field to its current stage of development.

European Scale Earthquake Data Exchange: ORFEUS-EMSC Joint Initiatives

NASA Astrophysics Data System (ADS)

Bossu, R.; van Eck, T.

2003-04-01

The European-Mediterranean Seismological Centre (EMSC) and the Observatories and Research Facilities for European Seismology (ORFEUS) are both active international organisations with different co-ordinating roles within European seismology. Both are non-governmental non-profit organisations, which have members/participants in more than 30 countries in Europe and its surroundings. Although different, their activities are complementary with ORFEUS focusing on broadband waveform data archiving and dissemination and EMSC focusing on seismological parameter data. The main EMSC activities are the alert system for potentially damaging earthquakes, a real time seismicity web page, the production of the Euro-Med. seismological bulletin, and the creation and maintenance of databases related to seismic hazard. All these activities are based on data contributions from seismological Institutes. The EMSC is also involved in a UNESCO programme to promote seismology and data exchange in the Middle-East and Northern Africa. ORFEUS aims at co-ordinating and promoting digital broadband seismology in Europe. To accomplish this, it operates a Data Centre to archive and distribute high quality digital data for research, co-ordinates four working groups and provides services through the Internet. More recently through an EC-infrastructure project MEREDIAN it has accomplished added co-ordination of data exchange and archiving between large European national data centres and realised the Virtual European Broadband Seismograph Network (VEBSN). To accomplish higher efficiency and better services to the seismological community, ORFEUS and EMSC have been working towards a closer collaboration. Fruits of this collaboration are the joint EC project EMICES, a common Expression of Interest 'NERIES' submitted June 2002 to the EC , integration of the automatic picks from the VEBSN into the EMSC rapid alert system and collaboration on common web page developments. Presently, we collaborate in a common EC Infrastructure proposal for European seismology. This presentation will provide a systematic overview of our current collaboration and joint initiatives.

Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (83rd, Phoenix, Arizona, August 9-12, 2000). International Communication Division.

ERIC Educational Resources Information Center

Association for Education in Journalism and Mass Communication.

The International Communication Division section of the proceedings contains the following 21 papers: "The European Press and the Euro: Media Agenda-Setting in a Cross-National Environment" (Olaf Werder); "Factors Affecting the Internet Adoption by Thai Journalists: A Diffusion of Innovation Study" (Anucha Thirakanont and…

Two color high operating temperature HgCdTe photodetectors grown by molecular beam epitaxy on silicon substrates

NASA Astrophysics Data System (ADS)

Velicu, S.; Bommena, R.; Morley, M.; Zhao, J.; Fahey, S.; Cowan, V.; Morath, C.

2013-09-01

The development of a broadband IR focal plane array poses several challenges in the area of detector design, material, device physics, fabrication process, hybridization, integration and testing. The purpose of our research is to address these challenges and demonstrate a high-performance IR system that incorporates a HgCdTe-based detector array with high uniformity and operability. Our detector architecture, grown using molecular beam epitaxy (MBE), is vertically integrated, leading to a stacked detector structure with the capability to simultaneously detect in two spectral bands. MBE is the method of choice for multiplelayer HgCdTe growth because it produces material of excellent quality and allows composition and doping control at the atomic level. Such quality and control is necessary for the fabrication of multicolor detectors since they require advanced bandgap engineering techniques. The proposed technology, based on the bandgap-tunable HgCdTe alloy, has the potential to extend the broadband detector operation towards room temperature. We present here our modeling, MBE growth and device characterization results, demonstrating Auger suppression in the LWIR band and diffusion limited behavior in the MWIR band.

An Investigation of Traveling-Wave Electrophoresis using a Trigonometric Potential

NASA Astrophysics Data System (ADS)

Vopal, James

Traveling-wave electrophoresis, a technique for microfluidic separations in lab-on-achip devices, is investigated using a trigonometric model that naturally incorporates the spatial periodicity of the device. Traveling-wave electrophoresis can be used to separate high-mobility ions from low-mobility ions in forensic and medical applications, with a separation threshold that can be tuned for specific applications by simply choosing the traveling wave frequency. Our simulations predict plateaus in the average ion velocity verses the mobility, plateaus that correspond to Farey fractions and yield Devil's staircases for non-zero discreteness values. The plateaus indicate that ions with different mobilities can travel with the same average velocity. To determine the conditions for chaos, Lyapunov exponents and contact maps are employed. Through the use of contact maps, the chaotic trajectories are determined to be either narrowband or broadband. Narrowband chaotic trajectories are exhibited in the plateaus of the average velocity, while broadband chaotic trajectories are exhibited where the average velocity varies nonmonotonically with the mobility. Narrowband chaos will be investigated in future work incorporating the role of diffusion. The results of this and future work can be used to develop new tools for electrophoretic separation.

Web-based radiology: a future to be created.

PubMed

Canadè, Adolfo; Palladino, Francesco; Pitzalis, Gianluca; Campioni, Paolo; Marano, Pasquale

2003-01-01

The impact of Internet on Medicine and Surgery is certainly remarkable, however the influence it had on Diagnostic Imaging was even stronger. The standardization of digital images acquired by the different medical imaging equipment has further facilitated the diffusion, transmission and communication in radiology within hospitals as well as on WEB. Radiology departments are bound to become "filmless" and with the present "tablet PC" radiological images will be directly transferred to the patient's bed in the relative electronic patient report. For radiology, interactive education could be envisaged with a tutor who guides the student(s) through the network. The Internet is an inexhaustible source of radiologic educational and information material with a number of sites of clinical cases, tutorial and teaching files, journals and magisterial lectures on-line. In a near future, the Internet could be applied in the simulation of clinicoradiologic cases or in applications of artificial intelligence with expert systems to support the solution of most complex cases.

Nonlinear Dynamics of a Diffusing Interface

NASA Technical Reports Server (NTRS)

Duval, Walter M. B.

2001-01-01

Excitation of two miscible-viscous liquids inside a bounded enclosure in a microgravity environment has shown the evolution of quasi-stationary waves of various modes for a range of parameters. We examine computationally the nonlinear dynamics of the system as the interface breakup and bifurcates to resonance structures typified by the Rayleigh-Taylor instability mechanism. Results show that when the mean steady field is much smaller than the amplitude of the sinusoidal excitation, the system behaves linearly, and growth of quasi-stationary waves occurs through the Kelvin-Helmholtz instability mechanism. However, as the amplitude of excitation increases, nonlinearity occurs through subharmonic bifurcation prior to broadband chaos.

Information and communication technology use and economic growth.

PubMed

Farhadi, Maryam; Ismail, Rahmah; Fooladi, Masood

2012-01-01

In recent years, progress in information and communication technology (ICT) has caused many structural changes such as reorganizing of economics, globalization, and trade extension, which leads to capital flows and enhancing information availability. Moreover, ICT plays a significant role in development of each economic sector, especially during liberalization process. Growth economists predict that economic growth is driven by investments in ICT. However, empirical studies on this issue have produced mixed results, regarding to different research methodology and geographical configuration of the study. This paper examines the impact of Information and Communication Technology (ICT) use on economic growth using the Generalized Method of Moments (GMM) estimator within the framework of a dynamic panel data approach and applies it to 159 countries over the period 2000 to 2009. The results indicate that there is a positive relationship between growth rate of real GDP per capita and ICT use index (as measured by the number of internet users, fixed broadband internet subscribers and the number of mobile subscription per 100 inhabitants). We also find that the effect of ICT use on economic growth is higher in high income group rather than other groups. This implies that if these countries seek to enhance their economic growth, they need to implement specific policies that facilitate ICT use.

Information and Communication Technology Use and Economic Growth

PubMed Central

Farhadi, Maryam; Ismail, Rahmah; Fooladi, Masood

2012-01-01

In recent years, progress in information and communication technology (ICT) has caused many structural changes such as reorganizing of economics, globalization, and trade extension, which leads to capital flows and enhancing information availability. Moreover, ICT plays a significant role in development of each economic sector, especially during liberalization process. Growth economists predict that economic growth is driven by investments in ICT. However, empirical studies on this issue have produced mixed results, regarding to different research methodology and geographical configuration of the study. This paper examines the impact of Information and Communication Technology (ICT) use on economic growth using the Generalized Method of Moments (GMM) estimator within the framework of a dynamic panel data approach and applies it to 159 countries over the period 2000 to 2009. The results indicate that there is a positive relationship between growth rate of real GDP per capita and ICT use index (as measured by the number of internet users, fixed broadband internet subscribers and the number of mobile subscription per 100 inhabitants). We also find that the effect of ICT use on economic growth is higher in high income group rather than other groups. This implies that if these countries seek to enhance their economic growth, they need to implement specific policies that facilitate ICT use. PMID:23152817

Measuring Solvent Content of Macromolecular Crystals Using Fluorescence Recovery after Photobleaching

NASA Astrophysics Data System (ADS)

Siewny, Matthew; Kmetko, Jan

2010-10-01

We work out a novel protocol for measuring the solvent content (the fraction of crystal volume occupied by solvent) in biological crystals by the technique of fluorescence recovery after photobleaching (FRAP). Crystals of proteins with widely varying known solvent content (lysozyme, thaumatin, catalase, and ferritin) were grown in their native solution doped with sodium fluorescein dye and hydroxylamine (to prevent dye from binding to amine groups of the proteins.) The crystals were irradiated by a broadband, high intensity light through knife slits, leaving a rectangular area of bleached dye within the crystals. Measuring the flow of dye out of the bleached area allowed us to construct a curve relating the diffusion coefficient of dye to the channel size within the crystals, by solving the diffusion equation analytically. This curve may be used to measure the solvent content of any biological crystal in its native solution and help determine the number of proteins in the crystallographic asymmetric unit cell in x-ray structure solving procedures.

An optically transparent metasurface for broadband microwave antireflection

NASA Astrophysics Data System (ADS)

Zhao, Jie; Zhang, Cheng; Cheng, Qiang; Yang, Jin; Cui, Tie Jun

2018-02-01

Metamaterial absorbers and diffusers provide powerful routes to decrease the backward reflection significantly with advantages of ultrathin profile and customized bandwidth. Simultaneous control of the absorption and scattering behaviors of the metamaterials which helps to improve the suppression capabilities of backward reflection, however, still remains a challenge. Aiming at this goal, we propose a metasurface constituted by two kinds of elements in a pseudorandom arrangement. By the use of indium tin oxide with moderate sheet resistance in the meta-atoms, enhanced absorption of energy can be achieved in a broad spectrum when interacted with illuminated waves. In the meanwhile, electromagnetic diffusion will be invoked from the destructive interference among the elements, giving rise to significant reduction of specular reflection as a result. Excellent agreements are observed between simulation and experiment with pronounced reflection suppression from 6.8 GHz to 19.4 GHz. In addition, the optical transparence of the patterns and substrates makes the proposed metasurface a promising candidate for future applications like photovoltaic solar cells and electromagnetic shielding glasses.

What are the sales practices of internet cigar vendors in China?

PubMed

Gao, Junling; Berg, Carla J; Huang, Lulu; Zheng, Pinpin; Fu, Hua

2015-05-01

To estimate the number of websites selling cigars in China and to examine their sales and marketing practices. Comprehensive searches were conducted using three keyword terms and two popular internet search engines. A total of 6000 sites were examined. Two raters examined the content of each site using a standardised coding instrument to assess geographic location, presence of warnings, products sold, and promotional strategies. We identified 106 internet cigar vendors, which were located in 16 cities, with most of them being located in developed cities (eg, Shanghai, Guangzhou, Hong Kong). Only 6.6% of internet cigar vendors featured health warnings, and 14.2% featured minimum age of sale warnings. More than 80% of sites sold large cigars, 34.9% sold small or mini cigars, 42.5% sold cigarettes, 28.3% sold tobacco leaves, and 73.6% sold cigar accessories. Third-party online payment was the most frequently accepted payment method. Scanned images of cigars or cigar boxes (92.5%), reduced prices (84.0%), and diffusion of cigar-related information (67.9%) were the most frequently used promotional strategies.+ Internet cigar vendors undermine tobacco control policies and pose many challenges for tobacco control advocates in China. New legislation and enforcement should address these issues. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Time domain diffuse optical spectroscopy: In vivo quantification of collagen in breast tissue

NASA Astrophysics Data System (ADS)

Taroni, Paola; Pifferi, Antonio; Quarto, Giovanna; Farina, Andrea; Ieva, Francesca; Paganoni, Anna Maria; Abbate, Francesca; Cassano, Enrico; Cubeddu, Rinaldo

2015-05-01

Time-resolved diffuse optical spectroscopy provides non-invasively the optical characterization of highly diffusive media, such as biological tissues. Light pulses are injected into the tissue and the effects of light propagation on re-emitted pulses are interpreted with the diffusion theory to assess simultaneously tissue absorption and reduced scattering coefficients. Performing spectral measurements, information on tissue composition and structure is derived applying the Beer law to the measured absorption and an empiric approximation to Mie theory to the reduced scattering. The absorption properties of collagen powder were preliminarily measured in the range of 600-1100 nm using a laboratory set-up for broadband time-resolved diffuse optical spectroscopy. Optical projection images were subsequently acquired in compressed breast geometry on 218 subjects, either healthy or bearing breast lesions, using a portable instrument for optical mammography that operates at 7 wavelengths selected in the range 635-1060 nm. For all subjects, tissue composition was estimated in terms of oxy- and deoxy-hemoglobin, water, lipids, and collagen. Information on tissue microscopic structure was also derived. Good correlation was obtained between mammographic breast density (a strong risk factor for breast cancer) and an optical index based on collagen content and scattering power (that accounts mostly for tissue collagen). Logistic regression applied to all optically derived parameters showed that subjects at high risk for developing breast cancer for their high breast density can effectively be identified based on collagen content and scattering parameters. Tissue composition assessed in breast lesions with a perturbative approach indicated that collagen and hemoglobin content are significantly higher in malignant lesions than in benign ones.

Information Filtering via Heterogeneous Diffusion in Online Bipartite Networks

PubMed Central

Zhang, Fu-Guo; Zeng, An

2015-01-01

The rapid expansion of Internet brings us overwhelming online information, which is impossible for an individual to go through all of it. Therefore, recommender systems were created to help people dig through this abundance of information. In networks composed by users and objects, recommender algorithms based on diffusion have been proven to be one of the best performing methods. Previous works considered the diffusion process from user to object, and from object to user to be equivalent. We show in this work that it is not the case and we improve the quality of the recommendation by taking into account the asymmetrical nature of this process. We apply this idea to modify the state-of-the-art recommendation methods. The simulation results show that the new methods can outperform these existing methods in both recommendation accuracy and diversity. Finally, this modification is checked to be able to improve the recommendation in a realistic case. PMID:26125631

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wojick, D E; Warnick, W L; Carroll, B C

With the United States federal government spending billions annually for research and development, ways to increase the productivity of that research can have a significant return on investment. The process by which science knowledge is spread is called diffusion. It is therefore important to better understand and measure the benefits of this diffusion of knowledge. In particular, it is important to understand whether advances in Internet searching can speed up the diffusion of scientific knowledge and accelerate scientific progress despite the fact that the vast majority of scientific information resources continue to be held in deep web databases that manymore » search engines cannot fully access. To address the complexity of the search issue, the term global discovery is used for the act of searching across heterogeneous environments and distant communities. This article discusses these issues and describes research being conducted by the Office of Scientific and Technical Information (OSTI).« less

Information Filtering via Heterogeneous Diffusion in Online Bipartite Networks.

PubMed

Zhang, Fu-Guo; Zeng, An

2015-01-01

The rapid expansion of Internet brings us overwhelming online information, which is impossible for an individual to go through all of it. Therefore, recommender systems were created to help people dig through this abundance of information. In networks composed by users and objects, recommender algorithms based on diffusion have been proven to be one of the best performing methods. Previous works considered the diffusion process from user to object, and from object to user to be equivalent. We show in this work that it is not the case and we improve the quality of the recommendation by taking into account the asymmetrical nature of this process. We apply this idea to modify the state-of-the-art recommendation methods. The simulation results show that the new methods can outperform these existing methods in both recommendation accuracy and diversity. Finally, this modification is checked to be able to improve the recommendation in a realistic case.

Fostering diffusion of scientific contents of National Society Cardiovascular Journals: The new ESC search engine.

PubMed

Alfonso, Fernando; Gonçalves, Lino; Pinto, Fausto; Timmis, Adam; Ector, Hugo; Ambrosio, Giuseppe; Vardas, Panos

2015-05-01

European Society of Cardiology (ESC) National Society Cardiovascular Journals (NSCJs) are high-quality biomedical journals focused on cardiovascular diseases. The Editors' Network of the ESC devises editorial initiatives aimed at improving the scientific quality and diffusion of NSCJ. In this article we will discuss on the importance of the Internet, electronic editions and open access strategies on scientific publishing. Finally, we will propose a new editorial initiative based on a novel electronic tool on the ESC web-page that may further help to increase the dissemination of contents and visibility of NSCJs. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

The Circulation of Scientific Articles in the Sphere of Web-Based Media: Citation Practices, Communities of Interests and Local Ties

PubMed Central

Renard, Julie

2016-01-01

On 5th December 2012, a scientific article reviewing a change in the feeding behaviour of the European catfish, one of the largest freshwater fish, was published in the American scientific journal, PLOS ONE, an open access journal, which also allows the mass publication of pictures and videos. Within a few days following the publication of this article, it was relayed by numerous web sites and generated a media craze. In this paper, we analyse the circulation of this scientific information in the sphere of Web-based media during the two months following its publication, by revealing the citation mechanisms of the original article and the logic of the Internet users participating in its diffusion. In addition, since the circulation of its informational content travelled beyond linguistic and geographical boundaries, we chose to compare the citation modalities and intertextual relationships of documents in the three countries where the article spread the most widely, namely: France, the United States and Great Britain. Even though our study shows that the media circulation of scientific papers operates in a traditional way, the intertextual analysis underlines the grand variety of participants (such as journalists, non-scientists, fishermen, technology enthusiasts and Internet users) involved in the diffusion of this information, each of them mobilizing different intertextual strategies, according to their various targets. They all transformed, reformulated and appropriated the scientific information according to their own, unique interests. This study also emphasizes the importance of journalistic websites as opinion relays. They were the first diffusers involved in spreading the information but this role was rarely acknowledged by the Internet users - through citations, for example. In contrast, we observed that amateurs’ communities (communities of practices and communities of interest of fishermen or of buzz fans), which only became involved in a second temporal phase of the spreading, preferred to build up their credibility through citations of the original article. Finally, this research helps to rethink the mechanisms of the circulation of scientific information in the Web-based media, highlighting both the variety and the inventiveness of the interactions between the academic and public spheres. PMID:27467573

The Circulation of Scientific Articles in the Sphere of Web-Based Media: Citation Practices, Communities of Interests and Local Ties.

PubMed

Lefebvre, Muriel; Renard, Julie

2016-01-01

On 5th December 2012, a scientific article reviewing a change in the feeding behaviour of the European catfish, one of the largest freshwater fish, was published in the American scientific journal, PLOS ONE, an open access journal, which also allows the mass publication of pictures and videos. Within a few days following the publication of this article, it was relayed by numerous web sites and generated a media craze. In this paper, we analyse the circulation of this scientific information in the sphere of Web-based media during the two months following its publication, by revealing the citation mechanisms of the original article and the logic of the Internet users participating in its diffusion. In addition, since the circulation of its informational content travelled beyond linguistic and geographical boundaries, we chose to compare the citation modalities and intertextual relationships of documents in the three countries where the article spread the most widely, namely: France, the United States and Great Britain. Even though our study shows that the media circulation of scientific papers operates in a traditional way, the intertextual analysis underlines the grand variety of participants (such as journalists, non-scientists, fishermen, technology enthusiasts and Internet users) involved in the diffusion of this information, each of them mobilizing different intertextual strategies, according to their various targets. They all transformed, reformulated and appropriated the scientific information according to their own, unique interests. This study also emphasizes the importance of journalistic websites as opinion relays. They were the first diffusers involved in spreading the information but this role was rarely acknowledged by the Internet users - through citations, for example. In contrast, we observed that amateurs' communities (communities of practices and communities of interest of fishermen or of buzz fans), which only became involved in a second temporal phase of the spreading, preferred to build up their credibility through citations of the original article. Finally, this research helps to rethink the mechanisms of the circulation of scientific information in the Web-based media, highlighting both the variety and the inventiveness of the interactions between the academic and public spheres.

A Community-Based IoT Personalized Wireless Healthcare Solution Trial.

PubMed

Catherwood, Philip A; Steele, David; Little, Mike; Mccomb, Stephen; Mclaughlin, James

2018-01-01

This paper presents an advanced Internet of Things point-of-care bio-fluid analyzer; a LoRa/Bluetooth-enabled electronic reader for biomedical strip-based diagnostics system for personalized monitoring. We undertake test simulations (technology trial without patient subjects) to demonstrate potential of long-range analysis, using a disposable test 'key' and companion Android app to form a diagnostic platform suitable for remote point-of-care screening for urinary tract infection (UTI). The 868 MHz LoRaWAN-enabled personalized monitor demonstrated sound potential with UTI test results being correctly diagnosed and transmitted to a remote secure cloud server in every case. Tests ranged over distances of 1.1-6.0 Km with radio path losses from 119-141 dB. All tests conducted were correctly and robustly received at the base station and relayed to the secure server for inspection. The UTI test strips were visually inspected for correct diagnosis based on color change and verified as 100% accurate. Results from testing across a number of regions indicate that such an Internet of Things medical solution is a robust and simple way to deliver next generation community-based smart diagnostics and disease management to best benefit patients and clinical staff alike. This significant step can be applied to any type of home or region, particularly those lacking suitable mobile signals, broadband connections, or even landlines. It brings subscription-free long-range bio-telemetry to healthcare providers and offers savings on regular clinician home visits or frequent clinic visits by the chronically ill. This paper highlights practical hurdles in establishing an Internet of Medical Things network, assisting informed deployment of similar future systems.

Dynamic nonrobotic telemicroscopy via skype: A cost effective solution to teleconsultation

PubMed Central

Sirintrapun, Sahussapont J.; Cimic, Adela

2012-01-01

Context: Skype is a peer to peer software application that has been historically used for voice and video calls, instant messaging, and file transfer over the Internet. Few studies are available using Skype specifically for telepathology. Aims: Our aim is to show that dynamic nonrobotic teleconsultation is possible and even effective via means of a standard microscope camera capable of live acquisition, Skype, an established broad band internet connection, and experienced pathologists. Settings and Design: Both the consulting “sending” pathologist and consultant “receiving” pathologist are reasonably experienced general surgical pathologists at junior attending level with several years of experience in sign out. Forty-five cases were chosen encompassing a broad range of surgical pathology specimens. The cases were prospectively evaluated with the consultant diagnosis used as a preliminary pathologic impression with the final diagnosis being confirmation. Materials and Methods: Versions of Skype 5.0 and above were used along with established broadband internet connections, usually between academic medical institutions. Results: Forty of forty-five cases (89%) were essentially concordant. In four of forty-five cases (9%), the consulting impression gave a differential, but favored an entity which did not match the final diagnosis. Only one case (2%) did the consulting impression not match the final diagnosis; a discordant opinion. Conclusions: The image quality via Skype screen sharing option is excellent. Essentially no lag time was seen. We have shown in our small pilot study that Skype is an effective cost-efficient means for teleconsultation, particularly in the setting of entity-related differential diagnoses in surgical pathology and when both the consulting and consultant pathologists are reasonably experienced. PMID:23024887

A Community-Based IoT Personalized Wireless Healthcare Solution Trial

PubMed Central

Steele, David; Little, Mike; Mccomb, Stephen; Mclaughlin, James

2018-01-01

This paper presents an advanced Internet of Things point-of-care bio-fluid analyzer; a LoRa/Bluetooth-enabled electronic reader for biomedical strip-based diagnostics system for personalized monitoring. We undertake test simulations (technology trial without patient subjects) to demonstrate potential of long-range analysis, using a disposable test ‘key’ and companion Android app to form a diagnostic platform suitable for remote point-of-care screening for urinary tract infection (UTI). The 868 MHz LoRaWAN-enabled personalized monitor demonstrated sound potential with UTI test results being correctly diagnosed and transmitted to a remote secure cloud server in every case. Tests ranged over distances of 1.1–6.0 Km with radio path losses from 119–141 dB. All tests conducted were correctly and robustly received at the base station and relayed to the secure server for inspection. The UTI test strips were visually inspected for correct diagnosis based on color change and verified as 100% accurate. Results from testing across a number of regions indicate that such an Internet of Things medical solution is a robust and simple way to deliver next generation community-based smart diagnostics and disease management to best benefit patients and clinical staff alike. This significant step can be applied to any type of home or region, particularly those lacking suitable mobile signals, broadband connections, or even landlines. It brings subscription-free long-range bio-telemetry to healthcare providers and offers savings on regular clinician home visits or frequent clinic visits by the chronically ill. This paper highlights practical hurdles in establishing an Internet of Medical Things network, assisting informed deployment of similar future systems. PMID:29888145

Real Time Quantification of Ultrafast Photoinduced Bimolecular Electron Transfer Rate: Direct Probing of the Transient Intermediate.

PubMed

Mukherjee, Puspal; Biswas, Somnath; Sen, Pratik

2015-08-27

Fluorescence quenching studies through steady-state and time-resolved measurements are inadequate to quantify the bimolecular electron transfer rate in bulk homogeneous solution due to constraints from diffusion. To nullify the effect of diffusion, direct evaluation of the rate of formation of a transient intermediate produced upon the electron transfer is essential. Methyl viologen, a well-known electron acceptor, produces a radical cation after accepting an electron, which has a characteristic strong and broad absorption band centered at 600 nm. Hence it is a good choice to evaluate the rate of photoinduced electron transfer reaction employing femtosecond broadband transient absorption spectroscopy. The time constant of the aforementioned process between pyrene and methyl viologen in methanol has been estimated to be 2.5 ± 0.4 ps using the same technique. The time constant for the backward reaction was found to be 14 ± 1 ps. These values did not change with variation of concentration of quencher, i.e., methyl viologen. Hence, we can infer that diffusion has no contribution in the estimation of rate constants. However, on changing the solvent from methanol to ethanol, the time constant of the electron transfer reaction has been found to increase and has accounted for the change in solvent reorganization energy.

Broadband network on-line data acquisition system with web based interface for control and basic analysis

NASA Astrophysics Data System (ADS)

Polkowski, Marcin; Grad, Marek

2016-04-01

Passive seismic experiment "13BB Star" is operated since mid 2013 in northern Poland and consists of 13 broadband seismic stations. One of the elements of this experiment is dedicated on-line data acquisition system comprised of both client (station) side and server side modules with web based interface that allows monitoring of network status and provides tools for preliminary data analysis. Station side is controlled by ARM Linux board that is programmed to maintain 3G/EDGE internet connection, receive data from digitizer, send data do central server among with additional auxiliary parameters like temperatures, voltages and electric current measurements. Station side is controlled by set of easy to install PHP scripts. Data is transmitted securely over SSH protocol to central server. Central server is a dedicated Linux based machine. Its duty is receiving and processing all data from all stations including auxiliary parameters. Server side software is written in PHP and Python. Additionally, it allows remote station configuration and provides web based interface for user friendly interaction. All collected data can be displayed for each day and station. It also allows manual creation of event oriented plots with different filtering abilities and provides numerous status and statistic information. Our solution is very flexible and easy to modify. In this presentation we would like to share our solution and experience. National Science Centre Poland provided financial support for this work via NCN grant DEC-2011/02/A/ST10/00284.

Portable, Fiber-Based, Diffuse Reflection Spectroscopy (DRS) Systems for Estimating Tissue Optical Properties.

PubMed

Vishwanath, Karthik; Chang, Kevin; Klein, Daniel; Deng, Yu Feng; Chang, Vivide; Phelps, Janelle E; Ramanujam, Nimmi

2011-02-01

Steady-state diffuse reflection spectroscopy is a well-studied optical technique that can provide a noninvasive and quantitative method for characterizing the absorption and scattering properties of biological tissues. Here, we compare three fiber-based diffuse reflection spectroscopy systems that were assembled to create a light-weight, portable, and robust optical spectrometer that could be easily translated for repeated and reliable use in mobile settings. The three systems were built using a broadband light source and a compact, commercially available spectrograph. We tested two different light sources and two spectrographs (manufactured by two different vendors). The assembled systems were characterized by their signal-to-noise ratios, the source-intensity drifts, and detector linearity. We quantified the performance of these instruments in extracting optical properties from diffuse reflectance spectra in tissue-mimicking liquid phantoms with well-controlled optical absorption and scattering coefficients. We show that all assembled systems were able to extract the optical absorption and scattering properties with errors less than 10%, while providing greater than ten-fold decrease in footprint and cost (relative to a previously well-characterized and widely used commercial system). Finally, we demonstrate the use of these small systems to measure optical biomarkers in vivo in a small-animal model cancer therapy study. We show that optical measurements from the simple portable system provide estimates of tumor oxygen saturation similar to those detected using the commercial system in murine tumor models of head and neck cancer.

The ethical duty to preserve the quality of scientific information

NASA Astrophysics Data System (ADS)

Arattano, Massimo; Gatti, Albertina; Eusebio, Elisa

2016-04-01

The commitment to communicate and divulge the knowledge acquired during his/her professional activity is certainly one of the ethical duties of the geologist. However nowadays, in the Internet era, the spreading of knowledge involves potential risks that the geologist should be aware of. These risks require a careful analysis aimed to mitigate their effects. The Internet may in fact contribute to spread (e.g. through websites like Wikipedia) information badly or even incorrectly presented. The final result could be an impediment to the diffusion of knowledge and a reduction of its effectiveness, which is precisely the opposite of the goal that a geologist should pursue. Specific criteria aimed to recognize incorrect or inadequate information would be, therefore, extremely useful. Their development and application might avoid, or at least reduce, the above mentioned risk. Ideally, such criteria could be also used to develop specific algorithms to automatically verify the quality of information available all over the Internet. A possible criterion will be here presented for the quality control of knowledge and scientific information. An example of its application in the field of geology will be provided, to verify and correct a piece of information available on the Internet. The proposed criterion could be also used for the simplification of the scientific information and the increase of its informative efficacy.

47 CFR 27.1217 - Competitive bidding procedures for the Broadband Radio Service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Broadband Radio Service. 27.1217 Section 27.1217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1217 Competitive bidding procedures for the Broadband Radio...

47 CFR 27.1217 - Competitive bidding procedures for the Broadband Radio Service.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Broadband Radio Service. 27.1217 Section 27.1217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1217 Competitive bidding procedures for the Broadband Radio...

47 CFR 27.1217 - Competitive bidding procedures for the Broadband Radio Service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Broadband Radio Service. 27.1217 Section 27.1217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1217 Competitive bidding procedures for the Broadband Radio...

47 CFR 27.1217 - Competitive bidding procedures for the Broadband Radio Service.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Broadband Radio Service. 27.1217 Section 27.1217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1217 Competitive bidding procedures for the Broadband Radio...

The bioethics discussion forum--an implementation of an Internet-based bioethics information analysis resource.

PubMed Central

Derse, A. R.; Krogull, S. R.

1995-01-01

Ethical analysis is crucial to decision making in biomedicine and health care, necessitating both rapid access to diffusely disseminated sources of information pertinent to bioethics and promotion of analysis in the field of bioethics through a resource for information analysis. We developed the Bioethics Discussion Forum, an Internet-based information analysis resource, in order to supplement the Bioethics Online Service with an interactive information medium to meet the demand for such an interactive resource. The Bioethics Discussion Forum has shown promise for information analysis, providing an arena for the review and discussion of complex bioethical information, establishing a connection nationally and internationally among individuals with high levels of expertise in bioethics, and providing a template for future interactive informatics services. PMID:8563245

A symmetrical image encryption scheme in wavelet and time domain

NASA Astrophysics Data System (ADS)

Luo, Yuling; Du, Minghui; Liu, Junxiu

2015-02-01

There has been an increasing concern for effective storages and secure transactions of multimedia information over the Internet. Then a great variety of encryption schemes have been proposed to ensure the information security while transmitting, but most of current approaches are designed to diffuse the data only in spatial domain which result in reducing storage efficiency. A lightweight image encryption strategy based on chaos is proposed in this paper. The encryption process is designed in transform domain. The original image is decomposed into approximation and detail components using integer wavelet transform (IWT); then as the more important component of the image, the approximation coefficients are diffused by secret keys generated from a spatiotemporal chaotic system followed by inverse IWT to construct the diffused image; finally a plain permutation is performed for diffusion image by the Logistic mapping in order to reduce the correlation between adjacent pixels further. Experimental results and performance analysis demonstrate the proposed scheme is an efficient, secure and robust encryption mechanism and it realizes effective coding compression to satisfy desirable storage.

[Hikikomori (ひきこもり): a culture-bound syndrome in the web 2.0 era].

PubMed

De Michele, Francesco; Caredda, Maria; Delle Chiaie, Roberto; Salviati, Massimo; Biondi, Massimo

2013-01-01

In 1998 the Japanese psychiatrist Tamaki Sait¯o invented the term hikikomori, referring to a condition characterised by a state of social withdrawal and avoidance (education, work, friendships) combined with a persistent isolation and confinement in the own home for at least 6 months, due to various factors. Initially it undoubtedly regarded a disorder related to a specific socio-cultural context, however in the last couple of years some cases of hikikomori behaviour have also been observed in other countries far from Japan, both geographically and culturally. By way of hypothesis this diffusion can probably be attributed to the cultural revolution represented by mass communication in the internet era; in particular, it seems to be closely related to the immediateness and diffusion of web 2.0, i.e. of social networks. Therefore, we report a case of hikikomori behaviour, who was referred to our ward. M. is a 28-year-old man, who has lived the last 10 years in a state of almost complete isolation. He has maintained contacts with the outside world almost exclusively via internet. He started several therapies with psychiatrists and psychologists, without achieving significant results. The case of M. represents, to our knowledge, the first case of hikikomori described in Italy.

[Spanish versus English as a language of publication and impact factor of Neurologia].

PubMed

Aleixandre-Benavent, R; Valderrama Zurián, J C; Alonso-Arroyo, A; Miguel-Dasit, A; González de Dios, J; de Granda Orive, Ji

2007-01-01

Although the English language is considered nowadays as the international language of medical publications, some important Spanish journals with impact factor in the Journal Citation Reports as Neurologia, they bet for the publication in Spanish. Neurologia is the official publication of the Sociedad Española de Neurología and there is the conviction that you can have a Spanish language journal with a high quality and a strong impact. Its presence in the most important international data bases and the possibility of free access to its contents through Internet guarantees its proper diffusion around the world. From the point of view of citation, the repercussion of the language for Neurologia, is reflected in the fact that the 46,8 % of the citations that receive are from journals that are published in Spanish. The main factor to improve the impact of the journal is the quality of their papers, as well as the fulfillment of the international rules about periodical publications, the punctuality in its edition and distribution, the presence in national and international bibliographical data bases, its free diffusion in Internet, the training of its researchers and their sensitivity to consult and cite articles that have been published in quality Spanish journals, when necessary.

47 CFR 27.1305 - Shared wireless broadband network.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Shared wireless broadband network. 27.1305... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

47 CFR 90.1405 - Shared wireless broadband network.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Shared wireless broadband network. 90.1405... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

47 CFR 27.1305 - Shared wireless broadband network.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Shared wireless broadband network. 27.1305... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

47 CFR 90.1405 - Shared wireless broadband network.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Shared wireless broadband network. 90.1405... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

47 CFR 27.1305 - Shared wireless broadband network.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false Shared wireless broadband network. 27.1305... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

47 CFR 90.1405 - Shared wireless broadband network.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Shared wireless broadband network. 90.1405... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

Infodemiology and Infoveillance: Framework for an Emerging Set of Public Health Informatics Methods to Analyze Search, Communication and Publication Behavior on the Internet

PubMed Central

2009-01-01

Infodemiology can be defined as the science of distribution and determinants of information in an electronic medium, specifically the Internet, or in a population, with the ultimate aim to inform public health and public policy. Infodemiology data can be collected and analyzed in near real time. Examples for infodemiology applications include: the analysis of queries from Internet search engines to predict disease outbreaks (eg. influenza); monitoring peoples' status updates on microblogs such as Twitter for syndromic surveillance; detecting and quantifying disparities in health information availability; identifying and monitoring of public health relevant publications on the Internet (eg. anti-vaccination sites, but also news articles or expert-curated outbreak reports); automated tools to measure information diffusion and knowledge translation, and tracking the effectiveness of health marketing campaigns. Moreover, analyzing how people search and navigate the Internet for health-related information, as well as how they communicate and share this information, can provide valuable insights into health-related behavior of populations. Seven years after the infodemiology concept was first introduced, this paper revisits the emerging fields of infodemiology and infoveillance and proposes an expanded framework, introducing some basic metrics such as information prevalence, concept occurrence ratios, and information incidence. The framework distinguishes supply-based applications (analyzing what is being published on the Internet, eg. on Web sites, newsgroups, blogs, microblogs and social media) from demand-based methods (search and navigation behavior), and further distinguishes passive from active infoveillance methods. Infodemiology metrics follow population health relevant events or predict them. Thus, these metrics and methods are potentially useful for public health practice and research, and should be further developed and standardized. PMID:19329408

Infodemiology and infoveillance: framework for an emerging set of public health informatics methods to analyze search, communication and publication behavior on the Internet.

PubMed

Eysenbach, Gunther

2009-03-27

Infodemiology can be defined as the science of distribution and determinants of information in an electronic medium, specifically the Internet, or in a population, with the ultimate aim to inform public health and public policy. Infodemiology data can be collected and analyzed in near real time. Examples for infodemiology applications include the analysis of queries from Internet search engines to predict disease outbreaks (eg. influenza), monitoring peoples' status updates on microblogs such as Twitter for syndromic surveillance, detecting and quantifying disparities in health information availability, identifying and monitoring of public health relevant publications on the Internet (eg. anti-vaccination sites, but also news articles or expert-curated outbreak reports), automated tools to measure information diffusion and knowledge translation, and tracking the effectiveness of health marketing campaigns. Moreover, analyzing how people search and navigate the Internet for health-related information, as well as how they communicate and share this information, can provide valuable insights into health-related behavior of populations. Seven years after the infodemiology concept was first introduced, this paper revisits the emerging fields of infodemiology and infoveillance and proposes an expanded framework, introducing some basic metrics such as information prevalence, concept occurrence ratios, and information incidence. The framework distinguishes supply-based applications (analyzing what is being published on the Internet, eg. on Web sites, newsgroups, blogs, microblogs and social media) from demand-based methods (search and navigation behavior), and further distinguishes passive from active infoveillance methods. Infodemiology metrics follow population health relevant events or predict them. Thus, these metrics and methods are potentially useful for public health practice and research, and should be further developed and standardized.

Webcasting in home and hospice care services: virtual communication in home care.

PubMed

Smith-Stoner, Marilyn

2011-06-01

The access to free live webcasting over home computers was much more available in 2007, when three military leaders from West Point, with the purpose of helping military personnel stay connected with their families when deployed, developed Ustream.tv. There are many types of Web-based video streaming applications. This article describes Ustream, a free and effective communication tool to virtually connect staff. There are many features in Ustream, but the most useful for home care and hospice service providers is its ability to broadcast sound and video to anyone with a broadband Internet connection, a chat room for users to interact during a presentation, and the ability to have a "co-host" or second person also broadcast simultaneously. Agencies that provide community-based services in the home will benefit from integration of Web-based video streaming into their communication strategy.

New Generation VLBI: Intraday UT1 Estimations

NASA Astrophysics Data System (ADS)

Ipatov, Alexander; Ivanov, Dmitriy; Ilin, Gennadiy; Smolentsev, Sergei; Gayazov, Iskander; Mardyshkin, Vyacheslav; Fedotov, Leonid; Stempkovski, Victor; Vytnov, Alexander; Salnikov, Alexander; Surkis, Igor; Mikhailov, Andrey; Marshalov, Dmitriy; Bezrukov, Ilya; Melnikov, Alexey; Ken, Voytsekh; Kurdubov, Sergei

2016-12-01

IAA finished work on the creation of the new generation radio interferometer with two VGOS antennas co-located at Badary and Zelenchukskaya. 48 single baseline one-hour VLBI sessions (up to four sessions per day) were performed from 04 Nov to 18 Nov 2015. Observations were carried out using wideband S/X receivers, three X-band and one S-band 512 MHz channels at one or two circular polarizations. Sessions consisted of about 60 scans with a 22-second minimum scan duration. The stations' broadband acquisition systems generated 1.5-3 TB data per session, which were transferred via Internet to the IAA FX correlator. The accuracy of the group delay in a single channel was 10-20 ps, which allows the use of every single channel's observations for geodetic analysis without synthesis. 156 single channel NGS-cards were obtained in total. The RMS of the differences between UT1-UTC estimates and IERS finals values is 19 μs.

Multimedia telehomecare system using standard TV set.

PubMed

Guillén, S; Arredondo, M T; Traver, V; García, J M; Fernández, C

2002-12-01

Nowadays, there are a very large number of patients that need specific health support at home. The deployment of broadband communication networks is making feasible the provision of home care services with a proper quality of service. This paper presents a telehomecare multimedia platform that runs over integrated services digital network and internet protocol using videoconferencing standards H.320 and H.323, and standard TV set for patient interaction. This platform allows online remote monitoring: ECG, heart sound, blood pressure. Usability, affordability, and interoperability were considered for the design and development of its hardware and software components. A first evaluation of technical and usability aspects were carried forward with 52 patients of a private clinic and 10 students in the University. Results show a high rate (mean = 4.33, standard deviation--SD = 1.63 in a five-points Likert scale) in the global perception of users on the quality of images, voice, and feeling of virtual presence.

Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre

NASA Astrophysics Data System (ADS)

Saglamyurek, Erhan; Jin, Jeongwan; Verma, Varun B.; Shaw, Matthew D.; Marsili, Francesco; Nam, Sae Woo; Oblak, Daniel; Tittel, Wolfgang

2015-02-01

The realization of a future quantum Internet requires the processing and storage of quantum information at local nodes and interconnecting distant nodes using free-space and fibre-optic links. Quantum memories for light are key elements of such quantum networks. However, to date, neither an atomic quantum memory for non-classical states of light operating at a wavelength compatible with standard telecom fibre infrastructure, nor a fibre-based implementation of a quantum memory, has been reported. Here, we demonstrate the storage and faithful recall of the state of a 1,532 nm wavelength photon entangled with a 795 nm photon, in an ensemble of cryogenically cooled erbium ions doped into a 20-m-long silica fibre, using a photon-echo quantum memory protocol. Despite its currently limited efficiency and storage time, our broadband light-matter interface brings fibre-based quantum networks one step closer to reality.

Digital media in the home: technical and research challenges

NASA Astrophysics Data System (ADS)

Ribas-Corbera, Jordi

2005-03-01

This article attempts to identify some of the technology and research challenges facing the digital media industry in the future. We first discuss several trends in the industry, such as the rapid growth of broadband Internet networks and the emergence of networking and media-capable devices in the home. Next, we present technical challenges that result from these trends, such as effective media interoperability in devices, and provide a brief overview of Windows Media, which is one of the technologies in the market attempting to address these challenges. Finally, given these trends and the state of the art, we argue that further research on data compression, encoder optimization, and multi-format transcoding can potentially make a significant technical and business impact in digital media. We also explore the reasons that research on related techniques such as wavelets or scalable video coding is having a relatively minor impact in today"s practical digital media systems.

A hybrid lightwave transmission system based on light injection/optoelectronic feedback techniques and fiber-VLLC integration

NASA Astrophysics Data System (ADS)

Tsai, Wen-Shing; Lu, Hai-Han; Li, Chung-Yi; Chen, Bo-Rui; Lin, Hung-Hsien; Lin, Dai-Hua

2016-04-01

A hybrid lightwave transmission system based on light injection/optoelectronic feedback techniques and fiber-visible laser light communication (VLLC) integration is proposed and experimentally demonstrated. To be the first one of its kind in employing light injection and optoelectronic feedback techniques in a fiber-VLLC integration lightwave transmission system, the light is successfully directly modulated with Community Access Television (CATV), 16-QAM, and 16-QAM-OFDM signals. Over a 40 km SMF and a 10 m free-space VLLC transport, good performances of carrier-to-noise ratio (CNR)/composite second-order (CSO)/composite triple-beat (CTB)/bit error rate (BER) are achieved for CATV/16-QAM/16-QAM-OFDM signals transmission. Such a hybrid lightwave transmission system would be very useful since it can provide broadband integrated services including CATV, Internet, and telecommunication services over both distribute fiber and in-building networks.

ICT-Supported Education; Learning Styles for Individual Knowledge Building

NASA Astrophysics Data System (ADS)

Haugen, Harald; Ask, Bodil; Bjørke, Sven Åke

School surveys and reports on integration of ICT in teaching and learning indicate that the technology is mainly used in traditional learning environments. Furthermore, the most frequently used software in the classrooms are general tools like word processors, presentation tools and Internet browsers. Recent attention among youngsters on social software / web 2.0, contemporary pedagogical approaches like social constructivism and long time experiences with system dynamics and simulations, seem to have a hard time being accepted by teachers and curriculum designers. How can teachers be trained to understand and apply these possibilities optimally that are now available in the classroom and online, on broadband connections and with high capacity computers? Some views on practices with the above-mentioned alternative approaches to learning are presented in this paper, focusing particularly on the options for online work and learning programmes. Here we have first hand experience with adult and mature academics, but also some background with other target groups.

78 FR 54241 - Proposed Information Collection; Comment Request; BroadbandMatch Web Site Tool

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-03

... Information Collection; Comment Request; BroadbandMatch Web Site Tool AGENCY: National Telecommunications and... goal of increased broadband deployment and use in the United States. The BroadbandMatch Web site began... empowering technology effectively. II. Method of Collection BroadbandMatch users access the Web site through...

QCL-based standoff and proximal chemical detectors

NASA Astrophysics Data System (ADS)

Dupuis, Julia R.; Hensley, Joel; Cosofret, Bogdan R.; Konno, Daisei; Mulhall, Phillip; Schmit, Thomas; Chang, Shing; Allen, Mark; Marinelli, William J.

2016-05-01

The development of two longwave infrared quantum cascade laser (QCL) based surface contaminant detection platforms supporting government programs will be discussed. The detection platforms utilize reflectance spectroscopy with application to optically thick and thin materials including solid and liquid phase chemical warfare agents, toxic industrial chemicals and materials, and explosives. Operation at standoff (10s of m) and proximal (1 m) ranges will be reviewed with consideration given to the spectral signatures contained in the specular and diffusely reflected components of the signal. The platforms comprise two variants: Variant 1 employs a spectrally tunable QCL source with a broadband imaging detector, and Variant 2 employs an ensemble of broadband QCLs with a spectrally selective detector. Each variant employs a version of the Adaptive Cosine Estimator for detection and discrimination in high clutter environments. Detection limits of 5 μg/cm2 have been achieved through speckle reduction methods enabling detector noise limited performance. Design considerations for QCL-based standoff and proximal surface contaminant detectors are discussed with specific emphasis on speckle-mitigated and detector noise limited performance sufficient for accurate detection and discrimination regardless of the surface coverage morphology or underlying surface reflectivity. Prototype sensors and developmental test results will be reviewed for a range of application scenarios. Future development and transition plans for the QCL-based surface detector platforms are discussed.

An angle-by-angle approach to predicting broadband high-frequency sound fields in rectangular enclosures with experimental comparison.

PubMed

Franzoni, Linda P; Elliott, Christopher M

2003-10-01

Experiments were performed on an elongated rectangular acoustic enclosure with different levels of absorptive material placed on side walls and an end wall. The acoustic source was a broadband high-frequency sound from a loudspeaker flush-mounted to an end wall of the enclosure. Measurements of sound-pressure levels were averaged in cross sections of the enclosure and then compared to theoretical results. Discrepancies between the experimental results and theoretical predictions that treated all incidence angles as equally probable led to the development of an angle-by-angle approach. The new approach agrees well with the experimentally obtained values. In addition, treating the absorptive material as bulk reacting rather than point reacting was found to significantly change the theoretical value for the absorption coefficient and to improve agreement with experiment. The new theory refines an earlier theory based on power conservation and locally diffuse assumptions. Furthermore, the new theory includes both the angle of incidence effects on the resistive and reactive properties of the absorptive material, and the effects of angle filtering, i.e., that reflecting waves associated with shallow angles become relatively stronger than those associated with steep angles as a function of distance from the source.

Investigation of the broadband ELF turbulence by observations of the FAST satellite

NASA Astrophysics Data System (ADS)

Golovchanskaya, I. V.; Kozelov, B. V.; Despirak, I. V.

2012-07-01

Scaling properties of variable electric fields in the topside ionosphere have been investigated on scales s from ˜30 m to 2 km by FAST electric field observations with sample rate of 512 s-1, in sixteen events of the broadband ELF turbulence. It is shown that down to scales of a few hundred meters, the power of turbulent electric fluctuations is a power law, ˜ s α. Scaling index α derived from the slope of logarithmic diagrams (LD) constructed by the discrete wavelet transform of data can be estimated as α = 2.2 ± 0.3, which is close to α estimate earlier reported for scales 1-30 km by electric field observations of the Dynamics Explorer 2 satellite. The behavior of α index is analyzed near the scale of the order of electron inertial length λe = c/ω0 (ω0 being the electron plasma frequency). At altitudes considered (700-2500 km), λe makes 100-900 m. We demonstrate that at scales ≤λe, a decrease of LD slope and deviation from the power law are typically observed. As pointed out in the discussion, this feature cannot be identified as a transition to the diffusion range, where dissipation of the turbulence occurs.

Asymmetric adiabatic couplers for fully-integrated broadband quantum-polarization state preparation.

PubMed

Chung, Hung-Pin; Huang, Kuang-Hsu; Wang, Kai; Yang, Sung-Lin; Yang, Shih-Yuan; Sung, Chun-I; Solntsev, Alexander S; Sukhorukov, Andrey A; Neshev, Dragomir N; Chen, Yen-Hung

2017-12-04

Spontaneous parametric down-conversion (SPDC) is a widely used method to generate entangled photons, enabling a range of applications from secure communication to tests of quantum physics. Integrating SPDC on a chip provides interferometric stability, allows to reduce a physical footprint, and opens a pathway to true scalability. However, dealing with different photon polarizations and wavelengths on a chip presents a number of challenging problems. In this work, we demonstrate an on-chip polarization beam-splitter based on z-cut titanium-diffused lithium niobate asymmetric adiabatic couplers (AAC) designed for integration with a type-II SPDC source. Our experimental measurements reveal unique polarization beam-splitting regime with the ability to tune the splitting ratios based on wavelength. In particular, we measured a splitting ratio of 17 dB over broadband regions (>60 nm) for both H- and V-polarized lights and a specific 50%/50% splitting ratio for a cross-polarized photon pair from the AAC. The results show that such a system can be used for preparing different quantum polarization-path states that are controllable by changing the phase-matching conditions in the SPDC over a broad band. Furthermore, we propose a fully integrated electro-optically tunable type-II SPDC polarization-path-entangled state preparation circuit on a single lithium niobate photonic chip.

76 FR 10295 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... Docket 07-100; FCC 11-6] Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the... framework for the nationwide public safety broadband network. This document considers and proposes... broadband networks operating in the 700 MHz band. This document addresses public safety broadband network...

Completion of spectral rotating shadowband radiometers and analysis of ARM spectral short-wave data. Technical progress report, November 1, 1994--October 31, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michalsky, J.; Harrison, L.

1995-04-26

The authors goal in the ARM program is the improvement of radiation models used in GCMs, especially in the shortwave, (1) by providing improved shortwave radiometric measurements for the testing of models and (2) by developing methods for retrieving climatologically sensitive parameters that serve as input to shortwave and longwave models. They are acquiring downwelling direct and diffuse spectral irradiance, at six wavelengths, plus downwelling broadband longwave, and upwelling and downwelling broadband shortwave irradiances that they combined with surface and upper air data from the Albany airport as a test data set for ARM modelers. They have also developed algorithmsmore » to improve shortwave measurements made at the Southern Great Plains (SGP) ARM site by standard thermopile instruments and by the multifolter rotating shadowband radiometer (MFRSR). However, the major objective of the program has been the development of two spectral versions of the rotating shadowband radiometer. The MFRSR, has become a workhose at the CART site in Oklahoma and Kansas, and it is widely deployed in other climate programs. They have spent most of their effort this year developing techniques to retrieve column aerosol, water vapor, and ozone from direct beam spectral measurements of the MFRSR. Additionally, they have had success in calculating shortwave surface albedo and aerosol optical depth from the ratio of direct to diffuse spectral irradiance. Using the surface albedo and the global irradiance, they have calculated cloud optical depths. From cloud optical depth and liquid water measured with the microwave radiometer, they have calculated effective liquid cloud particle radii. In each case the authors have attempted to validate the approach using independent measurements or retrievals of the parameters under investigation. With the exception of the ozone intercomparison, the corroborative measurements have been made at the SGP CART site. This report highlights these results.« less

Geometric phase coded metasurface: from polarization dependent directive electromagnetic wave scattering to diffusion-like scattering.

PubMed

Chen, Ke; Feng, Yijun; Yang, Zhongjie; Cui, Li; Zhao, Junming; Zhu, Bo; Jiang, Tian

2016-10-24

Ultrathin metasurface compromising various sub-wavelength meta-particles offers promising advantages in controlling electromagnetic wave by spatially manipulating the wavefront characteristics across the interface. The recently proposed digital coding metasurface could even simplify the design and optimization procedures due to the digitalization of the meta-particle geometry. However, current attempts to implement the digital metasurface still utilize several structural meta-particles to obtain certain electromagnetic responses, and requiring time-consuming optimization especially in multi-bits coding designs. In this regard, we present herein utilizing geometric phase based single structured meta-particle with various orientations to achieve either 1-bit or multi-bits digital metasurface. Particular electromagnetic wave scattering patterns dependent on the incident polarizations can be tailored by the encoded metasurfaces with regular sequences. On the contrast, polarization insensitive diffusion-like scattering can also been successfully achieved by digital metasurface encoded with randomly distributed coding sequences leading to substantial suppression of backward scattering in a broadband microwave frequency. The proposed digital metasurfaces provide simple designs and reveal new opportunities for controlling electromagnetic wave scattering with or without polarization dependence.

Assessing photoplethysmographic imaging performance beyond facial perfusion analysis

NASA Astrophysics Data System (ADS)

Amelard, Robert; Hughson, Richard L.; Greaves, Danielle K.; Clausi, David A.; Wong, Alexander

2017-02-01

Photoplethysmographic imaging (PPGI) systems are relatively new non-contact biophotonic diffuse reflectance systems able to assess arterial pulsations through transient changes in light-tissue interaction. Many PPGI studies have focused on extracting heart rate from the face or hand. Though PPGI systems can be used for widefield imaging of any anatomical area, whole-body investigations are lacking. Here, using a novel PPGI system, coded hemodynamic imaging (CHI), we explored and analyzed the pulsatility at major arterial locations across the whole body, including the neck (carotid artery), arm/wrist (brachial, radial and ulnar arteries), and leg/feet (popliteal and tibial arteries). CHI was positioned 1.5 m from the participant, and diffuse reactance from a broadband tungsten-halogen illumination was filtered using 850{1000 nm bandpass filter for deep tissue penetration. Images were acquired over a highly varying 24-participant sample (11/13 female/male, age 28.7+/-12.4 years, BMI 25.5+/-5.2 kg/m2), and a preliminary case study was performed. B-mode ultrasound images were acquired to validate observations through planar arterial characteristics.

Geometric phase coded metasurface: from polarization dependent directive electromagnetic wave scattering to diffusion-like scattering

PubMed Central

Chen, Ke; Feng, Yijun; Yang, Zhongjie; Cui, Li; Zhao, Junming; Zhu, Bo; Jiang, Tian

2016-01-01

Ultrathin metasurface compromising various sub-wavelength meta-particles offers promising advantages in controlling electromagnetic wave by spatially manipulating the wavefront characteristics across the interface. The recently proposed digital coding metasurface could even simplify the design and optimization procedures due to the digitalization of the meta-particle geometry. However, current attempts to implement the digital metasurface still utilize several structural meta-particles to obtain certain electromagnetic responses, and requiring time-consuming optimization especially in multi-bits coding designs. In this regard, we present herein utilizing geometric phase based single structured meta-particle with various orientations to achieve either 1-bit or multi-bits digital metasurface. Particular electromagnetic wave scattering patterns dependent on the incident polarizations can be tailored by the encoded metasurfaces with regular sequences. On the contrast, polarization insensitive diffusion-like scattering can also been successfully achieved by digital metasurface encoded with randomly distributed coding sequences leading to substantial suppression of backward scattering in a broadband microwave frequency. The proposed digital metasurfaces provide simple designs and reveal new opportunities for controlling electromagnetic wave scattering with or without polarization dependence. PMID:27775064

Coherent active methods for applications in room acoustics.

PubMed

Guicking, D; Karcher, K; Rollwage, M

1985-10-01

An adjustment of reverberation time in rooms is often desired, even for low frequencies where passive absorbers fail. Among the active (electroacoustic) systems, incoherent ones permit lengthening of reverberation time only, whereas coherent active methods will allow sound absorption as well. A coherent-active wall lining consists of loudspeakers with microphones in front and adjustable control electronics. The microphones pick up the incident sound and drive the speakers in such a way that the reflection coefficient takes on prescribed values. An experimental device for the one-dimensional case allows reflection coefficients between almost zero and about 1.5 to be realized below 1000 Hz. The extension to three dimensions presents problems, especially by nearfield effects. Experiments with a 3 X 3 loudspeaker array and computer simulations proved that the amplitude reflection coefficient can be adjusted between 10% and 200% for sinusoidal waves at normal and oblique incidence. Future developments have to make the system work with broadband excitation and in more diffuse sound fields. It is also planned to combine the active reverberation control with active diffusion control.

Review of optical breast imaging and spectroscopy

NASA Astrophysics Data System (ADS)

Grosenick, Dirk; Rinneberg, Herbert; Cubeddu, Rinaldo; Taroni, Paola

2016-09-01

Diffuse optical imaging and spectroscopy of the female breast is an area of active research. We review the present status of this field and discuss the broad range of methodologies and applications. Starting with a brief overview on breast physiology, the remodeling of vasculature and extracellular matrix caused by solid tumors is highlighted that is relevant for contrast in optical imaging. Then, the various instrumental techniques and the related methods of data analysis and image generation are described and compared including multimodality instrumentation, fluorescence mammography, broadband spectroscopy, and diffuse correlation spectroscopy. We review the clinical results on functional properties of malignant and benign breast lesions compared to host tissue and discuss the various methods to improve contrast between healthy and diseased tissue, such as enhanced spectroscopic information, dynamic variations of functional properties, pharmacokinetics of extrinsic contrast agents, including the enhanced permeability and retention effect. We discuss research on monitoring neoadjuvant chemotherapy and on breast cancer risk assessment as potential clinical applications of optical breast imaging and spectroscopy. Moreover, we consider new experimental approaches, such as photoacoustic imaging and long-wavelength tissue spectroscopy.

Infrared observations of Comet Austin (1990 V) by the COBE/Diffuse Infrared Background Experiment

NASA Technical Reports Server (NTRS)

Lisse, C. M.; Freudenreich, H. T.; Hauser, M. G.; Kelsall, T.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

1994-01-01

Comet Austin was observed by the Cosmic Background Explorer (COBE)/Diffuse Infrared Background Experiment (DIRBE) with broadband photometry at 1-240 micrometers during the comet's close passage by Earth in 1990 May. A 6 deg long (6 x 10(exp 6) km) dust tail was found at 12 and 25 micrometers, with detailed structure due to variations in particle properties and mass-loss rate. The spectrum of the central 42 x 42 sq arcmin pixel was found to agree with that of a graybody of temperature 309 +/- 5 K and optical depth 7.3 +/- 10(exp -8). Comparison with IUE and ground-based obervations indicates that particles of radius greater than 20 micrometers predominate by surface area. A mass-loss rate of 510 (+510/-205) kg/s and a total tail mass of 7 +/- 2 x 10(exp 10) kg was found for a model dust tail composed of Mie spheres with a differential particle mass distribution dn/d log m approx. m(exp -0.63) and 2:1 silicate:amorphous carbon composition by mass.

Product diffusion through on-demand information-seeking behaviour.

PubMed

Riedl, Christoph; Bjelland, Johannes; Canright, Geoffrey; Iqbal, Asif; Engø-Monsen, Kenth; Qureshi, Taimur; Sundsøy, Pål Roe; Lazer, David

2018-02-01

Most models of product adoption predict S-shaped adoption curves. Here we report results from two country-scale experiments in which we find linear adoption curves. We show evidence that the observed linear pattern is the result of active information-seeking behaviour: individuals actively pulling information from several central sources facilitated by modern Internet searches. Thus, a constant baseline rate of interest sustains product diffusion, resulting in a linear diffusion process instead of the S-shaped curve of adoption predicted by many diffusion models. The main experiment seeded 70 000 (48 000 in Experiment 2) unique voucher codes for the same product with randomly sampled nodes in a social network of approximately 43 million individuals with about 567 million ties. We find that the experiment reached over 800 000 individuals with 80% of adopters adopting the same product-a winner-take-all dynamic consistent with search engine driven rankings that would not have emerged had the products spread only through a network of social contacts. We provide evidence for (and characterization of) this diffusion process driven by active information-seeking behaviour through analyses investigating (a) patterns of geographical spreading; (b) the branching process; and (c) diffusion heterogeneity. Using data on adopters' geolocation we show that social spreading is highly localized, while on-demand diffusion is geographically independent. We also show that cascades started by individuals who actively pull information from central sources are more effective at spreading the product among their peers. © 2018 The Authors.

Product diffusion through on-demand information-seeking behaviour

PubMed Central

Bjelland, Johannes; Canright, Geoffrey; Iqbal, Asif; Qureshi, Taimur; Sundsøy, Pål Roe

2018-01-01

Most models of product adoption predict S-shaped adoption curves. Here we report results from two country-scale experiments in which we find linear adoption curves. We show evidence that the observed linear pattern is the result of active information-seeking behaviour: individuals actively pulling information from several central sources facilitated by modern Internet searches. Thus, a constant baseline rate of interest sustains product diffusion, resulting in a linear diffusion process instead of the S-shaped curve of adoption predicted by many diffusion models. The main experiment seeded 70 000 (48 000 in Experiment 2) unique voucher codes for the same product with randomly sampled nodes in a social network of approximately 43 million individuals with about 567 million ties. We find that the experiment reached over 800 000 individuals with 80% of adopters adopting the same product—a winner-take-all dynamic consistent with search engine driven rankings that would not have emerged had the products spread only through a network of social contacts. We provide evidence for (and characterization of) this diffusion process driven by active information-seeking behaviour through analyses investigating (a) patterns of geographical spreading; (b) the branching process; and (c) diffusion heterogeneity. Using data on adopters' geolocation we show that social spreading is highly localized, while on-demand diffusion is geographically independent. We also show that cascades started by individuals who actively pull information from central sources are more effective at spreading the product among their peers. PMID:29467257

Balancing Operations Security and Openness: Understanding the Military/Media Relationship in the Modern Media Environment

DTIC Science & Technology

2010-05-07

reporting on the capture and subsequent rescue of Private First Class Jessica Lynch during the opening days of Operation IRAQI FREEDOM. Lynch was...states, “ Globalised media, satellite communications, international travel and commerce, and the Internet facilitate the coordination of diffuse ideas...Military Review, (March-April 2008): 107-113. 26 and ideas allows the spread of ideologies inimical to globalisation , and provides the means for

Information accumulation system by inheritance and diffusion

NASA Astrophysics Data System (ADS)

Shin, J. K.

2009-09-01

This paper suggests a new model, called as the IAS (Information Accumulation System), for the description of the dynamic process that people use to accumulate their information (knowledge or opinion) for specific issues. Using the concept of information, both the internal and the external mechanism of the opinion dynamics are treated on a unified frame. The information is quantified as a real number with fixed bounds. New concepts, such as inheritance and differential absorption, are incorporated in IAS in addition to the conventional diffusive interaction between people. Thus, the dynamics of the IAS are governed by following three factors: inheritance rate, diffusivity and absorption rate. The original set of equations was solved with an agent based modeling technique. In addition, the individual equations for each of the agents were assembled and transformed into a set of equations for the ensemble averages, which are greatly reduced in number and can be solved analytically. The example simulations showed interesting results such as the critical behavior with respect to diffusivity, the information polarization out of zero-sum news and the dependence of the solutions on the initial conditions alone. The results were speculated in relation to today’s modern society where the diffusivity of information has been greatly increased through the internet and mobile phones.

Mothers "Google It Up:" Extending Communication Channel Behavior in Diffusion of Innovations Theory.

PubMed

Sundstrom, Beth

2016-01-01

This study employed qualitative methods, conducting 44 in-depth interviews with biological mothers of newborns to understand women's perceptions and use of new media, mass media, and interpersonal communication channels in relation to health issues. Findings contribute to theoretical and practical understandings of the role of communication channels in diffusion of innovations theory. In particular, this study provides a foundation for the use of qualitative research to advance applications of diffusion of innovations theory. Results suggest that participants resisted mass media portrayals of women's health. When faced with a health question, participants uniformly started with the Internet to "Google it up." Findings suggest new media comprise a new communication channel with new rules, serving the functions of both personal and impersonal influence. In particular, pregnancy and the postpartum period emerged as a time when campaign planners can access women in new ways online. As a result, campaign planners could benefit from introducing new ideas online and capitalizing on the strength of weak ties favored in new media. Results expand the innovativeness/needs paradox in diffusion of innovations theory by elaborating on the role of new media to reach underserved populations. These findings provide an opportunity to better understand patient information seeking through the lens of diffusion of innovations theory.

Global Interoperability of High Definition Video Streams Via ACTS and Intelsat

NASA Technical Reports Server (NTRS)

Hsu, Eddie; Wang, Charles; Bergman, Larry; Pearman, James; Bhasin, Kul; Clark, Gilbert; Shopbell, Patrick; Gill, Mike; Tatsumi, Haruyuki; Kadowaki, Naoto

2000-01-01

In 1993, a proposal at the Japan.-U.S. Cooperation in Space Program Workshop lead to a subsequent series of satellite communications experiments and demonstrations, under the title of Trans-Pacific High Data Rate Satellite Communications Experiments. The first of which is a joint collaboration between government and industry teams in the United States and Japan that successfully demonstrated distributed high definition video (HDV) post-production on a global scale using a combination of high data rate satellites and terrestrial fiber optic asynchronous transfer mode (ATM) networks. The HDV experiment is the first GIBN experiment to establish a dual-hop broadband satellite link for the transmission of digital HDV over ATM. This paper describes the team's effort in using the NASA Advanced Communications Technology Satellite (ACTS) at rates up to OC-3 (155 Mbps) between Los Angeles and Honolulu, and using Intelsat at rates up to DS-3 (45 Mbps) between Kapolei and Tokyo, with which HDV source material was transmitted between Sony Pictures High Definition Center (SPHDC) in Los Angeles and Sony Visual Communication Center (VCC) in Shinagawa, Tokyo. The global-scale connection also used terrestrial networks in Japan, the States of Hawaii and California. The 1.2 Gbps digital HDV stream was compressed down to 22.5 Mbps using a proprietary Mitsubishi MPEG-2 codec that was ATM AAL-5 compatible. The codec: employed four-way parallel processing. Improved versions of the codec are now commercially available. The successful post-production activity performed in Tokyo with a HDV clip transmitted from Los Angeles was predicated on the seamless interoperation of all the equipment between the sites, and was an exciting example in deploying a global-scale information infrastructure involving a combination of broadband satellites and terrestrial fiber optic networks. Correlation of atmospheric effects with cell loss, codec drop-out, and picture quality were made. Current efforts in the Trans-Pacific series plan to examine the use of Internet Protocol (IP)-related technologies over such an infrastructure. The use of IP allows the general public to be an integral part of the exciting activities, helps to examine issues in constructing the solar-system internet, and affords an opportunity to tap the research results from the (reliable) multicast and distributed systems communities. The current Trans- Pacific projects, including remote astronomy and digital library (visible human) are briefly described.

Information spread of emergency events: path searching on social networks.

PubMed

Dai, Weihui; Hu, Hongzhi; Wu, Tunan; Dai, Yonghui

2014-01-01

Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning.

The relationship investigation between factors affecting demand for broadband and the level of satisfaction among broadband customers in the South East Coast of Sabah, Malaysia

NASA Astrophysics Data System (ADS)

Hashim, S. H. A.; Hamid, F. A.; Kiram, J. J.; Sulaiman, J.

2017-09-01

This paper aims to investigate the relationship between factors that affecting the demand for broadband and the level of satisfaction. Previous researchers have found that the adoption of broadband is greatly influenced by many factors. Thus, in this study, a self-administered questionnaire was developed to obtain the factors affecting demand for broadband among broadband customers as well as their level of satisfaction. Pearson correlation, one-way analysis of variance (ANOVA) and t-test were used for statistical interpretation of the relationship. This study shows that there are better relationships between several factors over demand for broadband and satisfaction level.

Increasing utilization of Internet-based resources following efforts to promote evidence-based medicine: a national study in Taiwan.

PubMed

Weng, Yi-Hao; Kuo, Ken N; Yang, Chun-Yuh; Lo, Heng-Lien; Shih, Ya-Hui; Chen, Chiehfeng; Chiu, Ya-Wen

2013-01-07

Since the beginning of 2007, the National Health Research Institutes has been promoting the dissemination of evidence-based medicine (EBM). The current study examined longitudinal trends of behaviors in how hospital-based physicians and nurses have searched for medical information during the spread of EBM. Cross-sectional postal questionnaire surveys were conducted in nationally representative regional hospitals of Taiwan thrice in 2007, 2009, and 2011. Demographic data were gathered concerning gender, age, working experience, teaching appointment, academic degree, and administrative position. Linear and logistic regression models were used to examine predictors and changes over time. Data from physicians and nurses were collected in 2007 (n = 1156), 2009 (n = 2975), and 2011 (n = 3999). There were significant increases in the use of four Internet-based resources - Web portals, online databases, electronic journals, and electronic books - across the three survey years among physicians and nurses (p < 0.001). Access to textbooks and printed journals, however, did not change over the 4-year study period. In addition, there were significant relationships between the usage of Internet-based resources and users' characteristics. Age and faculty position were important predictors in relation to the usage among physicians and nurses, while academic degree served as a critical factor among nurses only. Physicians and nurses used a variety of sources to look for medical information. There was a steady increase in use of Internet-based resources during the diffusion period of EBM. The findings highlight the importance of the Internet as a prominent source of medical information for main healthcare professionals.

The diffusion of performance and image-enhancing drugs (PIEDs) on the internet: the abuse of the cognitive enhancer piracetam.

PubMed

Corazza, Ornella; Bersani, Francesco Saverio; Brunoro, Roberto; Valeriani, Giuseppe; Martinotti, Giovanni; Schifano, Fabrizio

2014-12-01

Performance and image-enhancing drugs (PIEDs), also known as "lifestyle drugs," are increasingly sold on the Internet to enhance cognitive as well as sexual, muscular, attentive, and other natural capacities. Our analysis focuses on the misuse of the cognitive enhancer piracetam. A literature review was carried out in PsychInfo and Pubmed database. Considering the absence of peer-reviewed data, review of additional sources of unstructured information from the Internet was carried out between February 2012 and July 2013. Additional searches were conducted using the Global Public Health Intelligence Network (GPHIN), a secure Internet-based early warning system developed by Health Canada and the World Health Organization (WHO), which monitors media reports in six languages, Arabic, Chinese, English, French, Russian, and Spanish. Piracetam is sold via illicit online pharmacies with no need of prescription at low prices. Buyers, mainly healthy individuals, purchase the product to enhance study- and work-related performances as well as for recreational purposes. Its nonmedical use is often associated with the occurrence of side effects such as hallucinations, psychomotor agitation, dysphoria, tiredness, dizziness, memory loss, headache, and severe diarrhoea; moreover, several users declared to have neither felt any cognitive improvement nor psychedelic effects. This is a new and fast-growing trend of abuse that needs to be extensively monitored and studied also by using near real-time and unstructured sources of information such as Internet news and online reports in order to acquire rapid knowledge and understanding. Products sold online might be counterfeits and this enhances related health risks.

75 FR 27984 - Broadband Technology Opportunities Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-19

....: 0907141137-0222-10] RIN 0660-ZA28 Broadband Technology Opportunities Program AGENCY: National...; Reopening of Application Filing Window for Broadband Technology Opportunities Program Comprehensive... filing window for the Broadband Technology Opportunities Program (BTOP) that the agency established...

75 FR 3791 - Broadband Technology Opportunities Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-22

... Department of Agriculture Rural Utilities Service Broadband Technology Opportunities Program; Notices #0;#0... 0660-ZA28 Broadband Technology Opportunities Program AGENCY: National Telecommunications and... for the Broadband Technology Opportunities Program (BTOP or Program) that the agency established...

Identification of periods of clear sky irradiance in time series of GHI measurements

DOE PAGES

Reno, Matthew J.; Hansen, Clifford W.

2016-01-18

In this study, we present a simple algorithm for identifying periods of time with broadband global horizontal irradiance (GHI) similar to that occurring during clear sky conditions from a time series of GHI measurements. Other available methods to identify these periods do so by identifying periods with clear sky conditions using additional measurements, such as direct or diffuse irradiance. Our algorithm compares characteristics of the time series of measured GHI with the output of a clear sky model without requiring additional measurements. We validate our algorithm using data from several locations by comparing our results with those obtained from amore » clear sky detection algorithm, and with satellite and ground-based sky imagery.« less

Identification of periods of clear sky irradiance in time series of GHI measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reno, Matthew J.; Hansen, Clifford W.

In this study, we present a simple algorithm for identifying periods of time with broadband global horizontal irradiance (GHI) similar to that occurring during clear sky conditions from a time series of GHI measurements. Other available methods to identify these periods do so by identifying periods with clear sky conditions using additional measurements, such as direct or diffuse irradiance. Our algorithm compares characteristics of the time series of measured GHI with the output of a clear sky model without requiring additional measurements. We validate our algorithm using data from several locations by comparing our results with those obtained from amore » clear sky detection algorithm, and with satellite and ground-based sky imagery.« less

Quantum theory of terahertz conductivity of semiconductor nanostructures

NASA Astrophysics Data System (ADS)

Ostatnický, T.; Pushkarev, V.; Němec, H.; Kužel, P.

2018-02-01

Efficient and controlled charge carrier transport through nanoelements is currently a primordial question in the research of nanoelectronic materials and structures. We develop a quantum-mechanical theory of the conductivity spectra of confined charge carriers responding to an electric field from dc regime up to optical frequencies. The broken translation symmetry induces a broadband drift-diffusion current, which is not taken into account in the analysis based on Kubo formula and relaxation time approximation. We show that this current is required to ensure that the dc conductivity of isolated nanostructures correctly attains zero. It causes a significant reshaping of the conductivity spectra up to terahertz or multiterahertz spectral ranges, where the electron scattering rate is typically comparable to or larger than the probing frequency.

Single-shot thermal ghost imaging using wavelength-division multiplexing

NASA Astrophysics Data System (ADS)

Deng, Chao; Suo, Jinli; Wang, Yuwang; Zhang, Zhili; Dai, Qionghai

2018-01-01

Ghost imaging (GI) is an emerging technique that reconstructs the target scene from its correlated measurements with a sequence of patterns. Restricted by the multi-shot principle, GI usually requires long acquisition time and is limited in observation of dynamic scenes. To handle this problem, this paper proposes a single-shot thermal ghost imaging scheme via a wavelength-division multiplexing technique. Specifically, we generate thousands of correlated patterns simultaneously by modulating a broadband light source with a wavelength dependent diffuser. These patterns carry the scene's spatial information and then the correlated photons are coupled into a spectrometer for the final reconstruction. This technique increases the speed of ghost imaging and promotes the applications in dynamic ghost imaging with high scalability and compatibility.

Innovations in the Analysis of Chandra-ACIS Observations

NASA Astrophysics Data System (ADS)

Broos, Patrick S.; Townsley, Leisa K.; Feigelson, Eric D.; Getman, Konstantin V.; Bauer, Franz E.; Garmire, Gordon P.

2010-05-01

As members of the instrument team for the Advanced CCD Imaging Spectrometer (ACIS) on NASA's Chandra X-ray Observatory and as Chandra General Observers, we have developed a wide variety of data analysis methods that we believe are useful to the Chandra community, and have constructed a significant body of publicly available software (the ACIS Extract package) addressing important ACIS data and science analysis tasks. This paper seeks to describe these data analysis methods for two purposes: to document the data analysis work performed in our own science projects and to help other ACIS observers judge whether these methods may be useful in their own projects (regardless of what tools and procedures they choose to implement those methods). The ACIS data analysis recommendations we offer here address much of the workflow in a typical ACIS project, including data preparation, point source detection via both wavelet decomposition and image reconstruction, masking point sources, identification of diffuse structures, event extraction for both point and diffuse sources, merging extractions from multiple observations, nonparametric broadband photometry, analysis of low-count spectra, and automation of these tasks. Many of the innovations presented here arise from several, often interwoven, complications that are found in many Chandra projects: large numbers of point sources (hundreds to several thousand), faint point sources, misaligned multiple observations of an astronomical field, point source crowding, and scientifically relevant diffuse emission.

Dispersion and nonlinear effects in OFDM-RoF system

NASA Astrophysics Data System (ADS)

Alhasson, Bader H.; Bloul, Albe M.; Matin, M.

2010-08-01

The radio-over-fiber (RoF) network has been a proven technology to be the best candidate for the wireless-access technology, and the orthogonal frequency division multiplexing (OFDM) technique has been established as the core technology in the physical layer of next generation wireless communication system, as a result OFDM-RoF has drawn attentions worldwide and raised many new research topics recently. At the present time, the trend of information industry is towards mobile, wireless, digital and broadband. The next generation network (NGN) has motivated researchers to study higher-speed wider-band multimedia communication to transmit (voice, data, and all sorts of media such as video) at a higher speed. The NGN would offer services that would necessitate broadband networks with bandwidth higher than 2Mbit/s per radio channel. Many new services emerged, such as Internet Protocol TV (IPTV), High Definition TV (HDTV), mobile multimedia and video stream media. Both speed and capacity have been the key objectives in transmission. In the meantime, the demand for transmission bandwidth increased at a very quick pace. The coming of 4G and 5G era will provide faster data transmission and higher bit rate and bandwidth. Taking advantages of both optical communication and wireless communication, OFDM Radio over Fiber (OFDM-RoF) system is characterized by its high speed, large capacity and high spectral efficiency. However, up to the present there are some problems to be solved, such as dispersion and nonlinearity effects. In this paper we will study the dispersion and nonlinearity effects and their elimination in OFDM-radio-over-fiber system.

Design of an Efficient CAC for a Broadband DVB-S/DVB-RCS Satellite Access Network

NASA Astrophysics Data System (ADS)

Inzerilli, Tiziano; Montozzi, Simone

2003-07-01

This paper deals with efficient utilization of network resources in an advanced broadband satellite access system. It proposes a technique for admission control of IP streams with guaranteed QoS which does not interfere with the particular BoD (Bandwidth on Demand) algorithm that handles access to uplink bandwidth, an essential part of a DVB- RCS architecture. This feature of the admission control greatly simplify its integration in the satellite network. The purpose of this admission control algorithm in particular is to suitably and dynamically configure the overall traffic control parameters, in the access terminal of the user and service segment, with a simple approach which does not introduces limitations and/or constraints to the BoD algorithm. Performance of the proposed algorithm is evaluated thorugh Opnet simulations using an ad-hoc platform modeling DVB-based satellite access.The results presented in this paper were obtained within SATIP6 project, which is sponsored within the 5th EU Research Programme, IST. The aims of the project are to evaluate and demonstrate key issues of the integration of satellite-based access networks into the Internet in order to support multimedia services over wide areas. The satellite link layer is based on DVB-S on the forward link and DVB-RCS on the return link. Adaptation and optimization of the DVB-RCS access standard in order to support QoS provision are central issues of the project. They are handled through an integration of Connection Admission Control (CAC), Traffic Shaping and Policing techniques.

Multi-site videoconferencing for home-based education of older people with chronic conditions: the Telehealth Literacy Project.

PubMed

Banbury, Annie; Parkinson, Lynne; Nancarrow, Susan; Dart, Jared; Gray, Len; Buckley, Jennene

2014-10-01

We examined the acceptability of multi-site videoconferencing as a method of providing group education to older people in their homes. There were 9 groups comprising 52 participants (mean age 73 years) with an average of four chronic conditions. Tablet computers or PCs were installed in participant's homes and connected to the Internet by the National Broadband Network (high-speed broad band network) or by the 4G wireless network. A health literacy and self-management programme was delivered by videoconference for 5 weeks. Participants were able to view and interact with all group members and the facilitator on their devices. During the study, 44 group videoconferences were conducted. Evaluation included 16 semi-structured interviews, 3 focus groups and a journal detailing project implementation. The participants reported enjoying home-based group education by videoconference and found the technology easy to use. Using home-based groups via videoconference was acceptable for providing group education, and considered particularly valuable for people living alone and/or with limited mobility. Audio difficulties were the most commonly reported problem. Participants connected with 4G experienced more problems (audio and visual) than participants on the National Broadband Network and those living in multi-dwelling residences reported more problems than those living in single-dwelling residences. Older people with little computer experience can be supported to use telehealth equipment. Telehealth has the potential to improve access to education about chronic disease self-management. © The Author(s) 2014 Reprints and permissions:]br]sagepub.co.uk/journalsPermissions.nav.

75 FR 3820 - Broadband Initiatives Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-22

... DEPARTMENT OF AGRICULTURE Rural Utilities Service RIN 0572-ZA01 Broadband Initiatives Program... policy and application procedures for the second round of funding under the broadband initiatives (the... Act) for the Broadband Initiatives Program (BIP) which provides loans, grants, and loan/grant...

Nanoscale diffusive memristor crossbars as physical unclonable functions.

PubMed

Zhang, R; Jiang, H; Wang, Z R; Lin, P; Zhuo, Y; Holcomb, D; Zhang, D H; Yang, J J; Xia, Q

2018-02-08

Physical unclonable functions have emerged as promising hardware security primitives for device authentication and key generation in the era of the Internet of Things. Herein, we report novel physical unclonable functions built upon the crossbars of nanoscale diffusive memristors that translate the stochastic distribution of Ag clusters in a SiO 2 matrix into a random binary bitmap that serves as a device fingerprint. The random dispersion of Ag led to an uneven number of clusters at each cross-point, which in turn resulted in a stochastic ability to switch in the Ag:SiO 2 diffusive memristors in an array. The randomness of the dispersion was a barrier to fingerprint cloning and the unique fingerprints of each device were persistent after fabrication. Using an optimized fabrication procedure, we maximized the randomness and achieved an inter-class Hamming distance of 50.68%. We also discovered that the bits were not flipping after over 10 4 s at 400 K, suggesting superior reliability of our physical unclonable functions. In addition, our diffusive memristor-based physical unclonable functions were easy to fabricate and did not require complicated post-processing for digitization and thus, provide new opportunities in hardware security applications.

Mammoth Mountain, California broadband seismic experiment

NASA Astrophysics Data System (ADS)

Dawson, P. B.; Pitt, A. M.; Wilkinson, S. K.; Chouet, B. A.; Hill, D. P.; Mangan, M.; Prejean, S. G.; Read, C.; Shelly, D. R.

2013-12-01

Mammoth Mountain is a young cumulo-volcano located on the southwest rim of Long Valley caldera, California. Current volcanic processes beneath Mammoth Mountain are manifested in a wide range of seismic signals, including swarms of shallow volcano-tectonic earthquakes, upper and mid-crustal long-period earthquakes, swarms of brittle-failure earthquakes in the lower crust, and shallow (3-km depth) very-long-period earthquakes. Diffuse emissions of C02 began after a magmatic dike injection beneath the volcano in 1989, and continue to present time. These indications of volcanic unrest drive an extensive monitoring effort of the volcano by the USGS Volcano Hazards Program. As part of this effort, eleven broadband seismometers were deployed on Mammoth Mountain in November 2011. This temporary deployment is expected to run through the fall of 2013. These stations supplement the local short-period and broadband seismic stations of the Northern California Seismic Network (NCSN) and provide a combined network of eighteen broadband stations operating within 4 km of the summit of Mammoth Mountain. Data from the temporary stations are not available in real-time, requiring the merging of the data from the temporary and permanent networks, timing of phases, and relocation of seismic events to be accomplished outside of the standard NCSN processing scheme. The timing of phases is accomplished through an interactive Java-based phase-picking routine, and the relocation of seismicity is achieved using the probabilistic non-linear software package NonLinLoc, distributed under the GNU General Public License by Alomax Scientific. Several swarms of shallow volcano-tectonic earthquakes, spasmodic bursts of high-frequency earthquakes, a few long-period events located within or below the edifice of Mammoth Mountain and numerous mid-crustal long-period events have been recorded by the network. To date, about 900 of the ~2400 events occurring beneath Mammoth Mountain since November 2011 have been relocated. Our goal is to derive high-resolution three-dimensional P- and S-wave velocity structure models of Mammoth Mountain. These models will enable more precise locations of the local seismicity, full waveform inversions of long-period seismicity, derivation of moment tensors for the seemingly brittle-failure high-frequency earthquakes, analyses of shear-wave splitting, and high-resolution relative relocation of seismicity using double differences.

Diffusion of new technology, health services and information after a crisis: a focus group study of the Sichuan "5.12" Earthquake.

PubMed

Zhou, Hong; Shi, Lu; Mao, Yuping; Tang, Juan; Zeng, Yu

2014-01-01

The Sichuan "5.12" Earthquake in 2008 occurred in a relatively underdeveloped area in China. The rainy weather, the mountainous environment and the local languages all posed major challenges to the dissemination of information and services after the disaster. By adopting a communication perspective, this study applies the diffusion of innovations theory to investigate how healthcare professionals diffused health technologies, health information and services during the rescue and relief operation. The authors conducted three focus group sessions with the health professionals who had attended to the rescue and relief work of the Sichuan "5.12" Earthquake in 2008. A range of questions regarding the diffusion of innovations were asked during these sessions. The health professionals used their cell phones to communicate with other healthcare providers, disseminated knowledge of health risks and injuries to affected residents with pamphlets and posters and attended daily meetings at the local government offices. They reported on the shortage of maritime satellite cell phones and large-size tents for medical use, and the absence of fully equipped ambulances. Volunteers, local health professionals and local officials provided health information and services in different ways. However, the diffusion of health information and services was less likely to reach those living next to transportation centers, in remote areas and in disaster areas neglected by the media. New communication devices such as cell phones and the mobile Internet enabled medical professionals to coordinate the rescue and relief work after this major natural disaster, at a time when the country's emergency response system still had plenty of room for improvement. In future, the mobile Internet should be used as a means of collecting bottom-up disaster reports so that the media will not neglect any disaster areas as they did during the Sichuan Earthquake. Rescue relief work would have been substantially easier if medical teams had been equipped with advanced appliances such as maritime satellite cell phones. "Disaster medicine" should be treated as a separate discipline in medical schools and receive more investment. Moreover, a stronger public health emergency response system is needed for more efficient dispatch and coordination. Copyright © 2012 John Wiley & Sons, Ltd.

["Left hemicranium, the cranial nerves" by Tramond: An anatomical model in wax from the Delmas, Orfila and Rouvière's Museum in Paris: description and tri-dimensional photographic reconstruction (TDPR)].

PubMed

Paravey, S; Le Floch-Prigent, P

2011-06-01

An anatomical model in wax made by Tramond (middle of the 19th century) represented the cranial nerves of a left hemicranium. The aim of the study was to verify its anatomical veracity, to realize a tri-dimensional visualization by computer, and finally to numerize and to diffuse it to the general public in the purpose of culture on the internet. The model belonged to the Delmas, Orfila and Rouvière Museum (Paris Descartes university). It represented the cranial nerves especially the facial and the trigeminal nerves and their branches. To perform the photographic rotation every 5° along 360°, we used a special device made of two identical superimposed marble disks linked by a ball bearing. A digital camera and the Quick Time Virtual Reality software were used. Seventy-two pictures were shot. This wax was realized with a great morphological accuracy from a true cranium as a support for the cranial nerves. The work of numerization and its free diffusion on the Internet permitted to deliver to everybody the images of this sample of the collection of the Orfila Museum, the pieces of which were evacuated on December 2009 after its closure. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

78 FR 45464 - Broadband Data Improvement Act; Eligible Entities Aggregate Form 477 Data

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-29

... or mobile broadband service provider advertises broadband transmission speeds of at least three.... DATES: Effective August 28, 2013. FOR FURTHER INFORMATION CONTACT: Suzanne Yelen, Assistant Division... availability. Providers of terrestrial mobile wireless (TMW) broadband services must continue to submit their...

Networked Nation: Broadband in America, 2007

ERIC Educational Resources Information Center

National Telecommunications and Information Administration, 2008

2008-01-01

This report highlights the dramatic growth of broadband in the United States. The report shows that the Administration's technology, regulatory and fiscal policies have stimulated innovation and competition, and encouraged investment in the U.S. broadband market contributing to significantly increased accessibility of broadband services. The…

New insights on the Gibraltar Arc geodynamics from SKS splitting: first contribution from the IberArray broad-band seismic network

NASA Astrophysics Data System (ADS)

Diaz Cusí, Jordi; Gallart, Josep; Villaseñor, Antonio

2010-05-01

The Rif-Betic region, comprising the Gibraltar Arc and the extensional Alboran basin and including the diffuse limit between the Eurasia and African plates, is complex and there is still not a commonly accepted hypothesis about the mechanism responsible for its formation, as models including lithospheric delamination, convective removal or subduction have been proposed. In this context, the knowledge about the presence and properties of upper mantle anisotropy from SKS splitting measurements can provide valuable information to constrain the different geodynamical models. The installation of new permanent and semi-permanent broadband stations in the region has allowed obtaining a first insight into the anisotropic properties (Buontempo et al, 2008) and evidenced the presence of geographical variations in the anisotropic parameters, even if the lack of data in the Northern part of Morocco did not allow to obtain a detailed image. We present here the first analysis of the data provided by the IberArray broad-band seismic network that will allow a significant improvement the coverage of this area. The IberArray broad-band seismic network was deployed over this region for about 18 months, beginning in summer/fall 2007 in the framework of the large-scale Topo-Iberia project. This portable array, formed by up to 55 new generation dataloggers equipped with broad-band seismometers, has covered the southern part of Iberia (35 stations) and northern Morocco (20 stations) in an approximately regular grid, with a nominal spacing of 60 km. Data from more than 35 permanent broadband stations maintained by different institutions operating in the region has also been integrated into the IberArray database. Events with epicentral distances between 85 and 120 degrees and magnitude greater than 6.0 are systematically extracted from the continuous dataset and SKS and SKKS phases are inspected for anisotropy using the SplitLab software. Processing of the whole dataset is still ongoing, but the available results, including those for the entire year 2008, significantly improve the spatial resolution of SKS measurements in this region. The inferred fast velocity directions (FVD) clearly show a spectacular rotation along the Gibraltar arc, following the curvature of the Rif-Betic chain, from roughly N65E beneath the Betics to close to N65W beneath the Rif chain. Stations located in the South and South-east edges of the array, show a distinct pattern, with FVD oriented NE-SW to E-W. The results for some sites suggest the presence of complex anisotropy features, probably including two anisotropic layers. The obtained FVD results are compatible with rollback / subduction models, while convective-removal and delamination models seem unlikely to be compatible with our results. The FVD variations along the Gibraltar arc could be explained by fossil anisotropy acquired during the Eocene Western Mediterranean subduction, while the change in FVD observed to the South and South-East of the Rif-Betic chain can be related to the imprint of a flow episode around the Alboran high velocity slab during its Miocene fragmentation from the Algerian slab.

Connecting America: The National Broadband Plan

ERIC Educational Resources Information Center

Federal Communications Commission, 2010

2010-01-01

In early 2009, Congress directed the Federal Communications Commission (FCC) to develop a National Broadband Plan to ensure every American has "access to broadband capability." Congress also required that this plan include a detailed strategy for achieving affordability and maximizing use of broadband to advance "consumer welfare, civic…

Gas-phase broadband spectroscopy using active sources: progress, status, and applications

PubMed Central

Cossel, Kevin C.; Waxman, Eleanor M.; Finneran, Ian A.; Blake, Geoffrey A.; Ye, Jun; Newbury, Nathan R.

2017-01-01

Broadband spectroscopy is an invaluable tool for measuring multiple gas-phase species simultaneously. In this work we review basic techniques, implementations, and current applications for broadband spectroscopy. We discuss components of broad-band spectroscopy including light sources, absorption cells, and detection methods and then discuss specific combinations of these components in commonly-used techniques. We finish this review by discussing potential future advances in techniques and applications of broad-band spectroscopy. PMID:28630530

Information Spread of Emergency Events: Path Searching on Social Networks

PubMed Central

Hu, Hongzhi; Wu, Tunan

2014-01-01

Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning. PMID:24600323

[The Revista Médica de Chile in a science library in the Internet].

PubMed

Reyes, H

2001-02-01

Medical journals published in non-English languages face a handicap: their worldwide readership and citation are reduced in comparison to journals published in English. This handicap is worse for small journals edited in developing countries, regardless of whether they publish original research articles including abstracts in English. To facilitate the international diffusion of selected Chilean scientific journals, the "Comisión Nacional de Investigación Científica y Tecnológica" enforced the program "SciELO Chile" with a web site in Internet (www.scielo.cl) including the full text of articles published in recent issues. Revista Médica de Chile is the first Chilean medical journal that appears in this web site, sponsored by the National Library of Medicine, Washington D.C. We expect that this web site will give a favorable input to authors of articles published in our journal.

75 FR 35989 - Facilitating the Provision of Fixed and Mobile Broadband Access, Educational and Other Advanced...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-24

...] Facilitating the Provision of Fixed and Mobile Broadband Access, Educational and Other Advanced Services in the...), clarifying the requirements necessary for Broadband Radio Service (BRS) and Educational Broadband Service (EBS) licensees to demonstrate substantial service and ensure that BRS licensees of new initial...

47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

Code of Federal Regulations, 2013 CFR

2013-10-01

... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service Relocation Procedures for the...

47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

Code of Federal Regulations, 2012 CFR

2012-10-01

... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service Relocation Procedures for the...

47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

Code of Federal Regulations, 2014 CFR

2014-10-01

... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service Relocation Procedures for the...

Relationship of Topside Ionospheric Ion Outflows to Auroral Forms and Precipitations, Plasma Waves, and Convection Observed by POLAR

NASA Technical Reports Server (NTRS)

Hirahara, M.; Horwitz, J. L.; Moore, T. E.; Germany, G. A.; Spann, J. F.; Peterson, W. K.; Shelley, E. G.; Chandler, M. O.; Giles, B. L.; Craven, P. D.;

Relationship of Topside Ionospheric Ion Outflows to Auroral Forms and Precipitation, Plasma Waves, and Convection Observed by Polar

NASA Technical Reports Server (NTRS)

Hirahara, M.; Horwitz, J. L.; Moore, T. E.; Germany, G. A.; Spann, J. F.; Peterson, W. K.; Shelley, E. G.; Chandler, M. O.; Giles, B. L.; Craven, P. D.;

Broadband Observations and Modeling of the Shell-Type Supernova Remnant G347.3-0.5

NASA Technical Reports Server (NTRS)

Ellison, Donald C.; Slane, Patrick O.; Gaensler, Bryan M.

2002-01-01

The supernova remnant G347.3-0.5 emits a featureless power law in X-rays, thought to indicate shock acceleration of electrons to high energies. We here produce a broadband spectrum of the bright northwest limb of this source by combining radio observations from the Australia Telescope Compact Array (ATCA), X-ray observations from the Advanced Satellite for Cosmology and Astrophysics (ASCA), and TeV gamma-ray observations from the CANGAROO imaging Cerenkov telescope. We assume that this emission is produced by an electron population generated by diffusive shock acceleration at the remnant forward shock. The nonlinear aspects of the particle acceleration force a connection between the widely different wavelength bands and between the electrons and the unseen ions, presumably accelerated simultaneously with the electrons. This allows us to infer the relativistic proton spectrum and estimate ambient parameters such as the supernova explosion energy, magnetic field, matter density in the emission region, and efficiency of the shock acceleration process. We find convincing evidence that the shock acceleration is efficient, placing greater than 25% of the shock kinetic energy flux into relativistic ions. Despite this high efficiency, the maximum electron and proton energies, while depending somewhat on assumptions for the compression of the magnetic field in the shock, are well below the observed 'knee' at 10(exp 15) eV in the Galactic cosmic-ray spectrum.

Conformal Membrane Reflectors for Deployable Optics

NASA Technical Reports Server (NTRS)

Hood, Patrick J.; Keys, Andrew S. (Technical Monitor)

2002-01-01

This presentation reports the Phase I results on NASA's Gossamer Spacecraft Exploratory Research and Technology Program. Cornerstone Research Group, Inc., the University of Rochester, and International Photonics Consultants collaborated to investigate the feasibility of free-standing, liquid-crystal-polymer (LCP) reflectors for integration into space-based optical systems. The goal of the program was to achieve large-diameter, broadband. reflective membranes that are resistant to the effects of space, specifically cryogenic environments and gamma-ray irradiation. Additionally, we assessed the applicability of utilizing the technology as tight sails, since, by their very nature, these films offer high-reflectivity at specified wavelengths. Previous research programs have demonstrated all-polymer, narrow-band Specular reflectors and diffuse membrane reflectors. The feasibility of fabricating an all-polymer broadband specular reflector and a narrow-band specular membrane reflector was assessed in the Phase I Gossamer program. In addition, preliminary gamma irradiation studies were conducted to determine the stability of the polymer reflectors to radiation. Materials and process technology were developed to fabricate coupon-scale reflectors of both broad- and narrow-band specular reflectors in Phase 1. This presentation will report the results of these studies, including, the performance of a narrow-band specular membrane. Gamma irradiation exposures indicate limited impact on the optical performance although additional exposure studies are warranted. Plans to scale up the membrane fabrication process will be presented.

Chaos-assisted broadband momentum transformation in optical microresonators

NASA Astrophysics Data System (ADS)

Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

2017-10-01

The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks.

Use of a secure Internet Web site for collaborative medical research.

PubMed

Marshall, W W; Haley, R W

2000-10-11

Researchers who collaborate on clinical research studies from diffuse locations need a convenient, inexpensive, secure way to record and manage data. The Internet, with its World Wide Web, provides a vast network that enables researchers with diverse types of computers and operating systems anywhere in the world to log data through a common interface. Development of a Web site for scientific data collection can be organized into 10 steps, including planning the scientific database, choosing a database management software system, setting up database tables for each collaborator's variables, developing the Web site's screen layout, choosing a middleware software system to tie the database software to the Web site interface, embedding data editing and calculation routines, setting up the database on the central server computer, obtaining a unique Internet address and name for the Web site, applying security measures to the site, and training staff who enter data. Ensuring the security of an Internet database requires limiting the number of people who have access to the server, setting up the server on a stand-alone computer, requiring user-name and password authentication for server and Web site access, installing a firewall computer to prevent break-ins and block bogus information from reaching the server, verifying the identity of the server and client computers with certification from a certificate authority, encrypting information sent between server and client computers to avoid eavesdropping, establishing audit trails to record all accesses into the Web site, and educating Web site users about security techniques. When these measures are carefully undertaken, in our experience, information for scientific studies can be collected and maintained on Internet databases more efficiently and securely than through conventional systems of paper records protected by filing cabinets and locked doors. JAMA. 2000;284:1843-1849.

Increasing utilization of Internet-based resources following efforts to promote evidence-based medicine: a national study in Taiwan

PubMed Central

2013-01-01

Background Since the beginning of 2007, the National Health Research Institutes has been promoting the dissemination of evidence-based medicine (EBM). The current study examined longitudinal trends of behaviors in how hospital-based physicians and nurses have searched for medical information during the spread of EBM. Methods Cross-sectional postal questionnaire surveys were conducted in nationally representative regional hospitals of Taiwan thrice in 2007, 2009, and 2011. Demographic data were gathered concerning gender, age, working experience, teaching appointment, academic degree, and administrative position. Linear and logistic regression models were used to examine predictors and changes over time. Results Data from physicians and nurses were collected in 2007 (n = 1156), 2009 (n = 2975), and 2011 (n = 3999). There were significant increases in the use of four Internet-based resources – Web portals, online databases, electronic journals, and electronic books – across the three survey years among physicians and nurses (p < 0.001). Access to textbooks and printed journals, however, did not change over the 4-year study period. In addition, there were significant relationships between the usage of Internet-based resources and users’ characteristics. Age and faculty position were important predictors in relation to the usage among physicians and nurses, while academic degree served as a critical factor among nurses only. Conclusions Physicians and nurses used a variety of sources to look for medical information. There was a steady increase in use of Internet-based resources during the diffusion period of EBM. The findings highlight the importance of the Internet as a prominent source of medical information for main healthcare professionals. PMID:23289500

Development of a self-made framework for the acquisition and communication of real-time precipitation data

NASA Astrophysics Data System (ADS)

Pedrozo-Acuña, A.; Magos-Hernández, J. A.; Sánchez-Peralta, J. A.; Blanco-Figueroa, J.; Breña-Naranjo, J. A.

2017-12-01

This contribution presents a real-time system for issuing warnings of intense precipitation events during major storms, developed for Mexico City, Mexico. The system is based on high-temporal resolution (Dt=1min) measurements of precipitation in 10 different points within the city, which report variables such as intensity, number of raindrops, raindrop size, kinetic energy, fall velocity, etc. Each one of these stations, is comprised of an optical disdrometer to measure size and fall velocity of hydrometeors, a solar panel to guarantee an uninterrupted power supply, a wireless broadband access to internet, and a resource constrained device known as Raspberry Pi3 for the processing, storage and sharing of the sensor data over the world wide web. The self-made developed platform follows a component-based system paradigm allowing users to implement custom algorithms and models depending on application requirements. The system is in place since July 2016, and continuous measurements of rainfall in real-time are published over the internet through the webpage www.oh-iiunam.mx. Additionally, the developed platform for the data collection and management interacts with the social network known as Twitter to enable real-time warnings of precipitation events. Key contribution of this development is the design and implementation of a scalable, easy to use, interoperable platform that facilitates the development of real-time precipitation sensor networks and warnings. The system is easy to implement and could be used as a prototype for systems in other regions of the world.

The Evolution of South Korea's Broadband Convergence Network, 2004-2007

ERIC Educational Resources Information Center

Menon, Siddhartha Shankar

2010-01-01

Broadband holds a critical position in the progress of economic and social indicators by connecting consumers, businesses and governments. South Korea has consistently been the global leader in broadband deployment since 1999. In the last ten years the Korean government has pursued several strategies for its broadband policy. The purpose of this…

Using VoIP to compete.

PubMed

Werbach, Kevin

2005-09-01

Internet telephony, or VoIP, is rapidly replacing the conventional kind. This year, for the first time, U.S. companies bought more new Internet-phone connections than standard lines. The major driver behind this change is cost. But VoIP isn't just a new technology for making old-fashioned calls cheaper, says consultant Kevin Werbach. It is fundamentally changing how companies use voice communications. What makes VoIP so powerful is that it turns voice into digital data packets that can be stored, copied, combined with other data, and distributed to virtually any device that connects to the Internet. And it makes it simple to provide all the functionality of a corporate phone-call features, directories, security-to anyone anywhere there's broadband access. That fosters new kinds of businesses such as virtual call centers, where widely dispersed agents work at all hours from their homes. The most successful early adopters, says Werbach, will focus more on achieving business objectives than on saving money. They will also consider how to push VoIP capabilities out to the extended organization, making use of everyone as a resource. Deployment may be incremental, but companies should be thinking about where VoIP could take them. Executives should ask what they could do if, on demand, they could bring all their employees, customers, suppliers, and partners together in a virtual room, with shared access to every modern communications and computing channel. They should take a fresh look at their business processes to find points at which richer and more customizable communications could eliminate bottlenecks and enhance quality. The important dividing line won't be between those who deploy Vol P and those who don't, or even between early adopters and laggards. It will be between those who see Vol P as just a new way to do the same old things and those who use itto rethink their entire businesses.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manzini, Gianmarco

This document contains working annotations on the Virtual Element Method (VEM) for the approximate solution of diffusion problems with variable coefficients. To read this document you are assumed to have familiarity with concepts from the numerical discretization of Partial Differential Equations (PDEs) and, in particular, the Finite Element Method (FEM). This document is not an introduction to the FEM, for which many textbooks (also free on the internet) are available. Eventually, this document is intended to evolve into a tutorial introduction to the VEM (but this is really a long-term goal).

76 FR 51271 - Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the 700 MHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-18

... Docket 07-100; FCC 11-6] Implementing a Nationwide, Broadband, Interoperable Public Safety Network in the... interoperable public safety broadband network. The establishment of a common air interface for 700 MHz public safety broadband networks will create a foundation for interoperability and provide a clear path for the...

A Comprehensive Review of Helicopter Noise Literature

DTIC Science & Technology

1975-06-01

Broadband Noise .... ........................ .0.0.0 13 Impulsive Noise .......... ........... ............... ... *. i Introduction... broadband noise is probably the turbulence in the flow seen by the rotor blades. Trhe prediction of rotor broadband noise based on rotor geometry amd...acoustic processes, but rely on generalization of existing test data. The recent impetus to study broadband noise is the result of reducing

Fermi-LAT and Suzaku Observations of the Radio Galaxy Centaurus B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katsuta, Junichiro; /Stanford U., HEPL /KIPAC, Menlo Park; Tanaka, Y.T.

2012-08-17

CentaurusB is a nearby radio galaxy positioned in the Southern hemisphere close to the Galactic plane. Here we present a detailed analysis of about 43 months accumulation of Fermi-LAT data and of newly acquired Suzaku X-ray data for Centaurus B. The source is detected at GeV photon energies, although we cannot completely exclude the possibility that it is an artifact due to incorrect modeling of the bright Galactic diffuse emission in the region. The LAT image provides a weak hint of a spatial extension of the {gamma} rays along the radio lobes, which is consistent with the lack of sourcemore » variability in the GeV range. We note that the extension cannot be established statistically due to the low number of the photons. Surprisingly, we do not detect any diffuse emission of the lobes at X-ray frequencies, with the provided upper limit only marginally consistent with the previously claimed ASCA flux. The broad-band modeling shows that the observed {gamma}-ray flux of the source may be produced within the lobes, if the diffuse non-thermal X-ray emission component is not significantly below the derived Suzaku upper limit. This association would imply that efficient in-situ acceleration of the ultrarelativistic particles is occurring and that the lobes are dominated by the pressure from the relativistic particles. However, if the diffuse X-ray emission is much below the Suzaku upper limits, the observed {gamma}-ray flux is not likely to be produced within the lobes, but instead within the unresolved core of Centaurus B. In this case, the extended lobes could be dominated by the pressure of the magnetic field.« less

Non-invasive tissue temperature measurements based on quantitative diffuse optical spectroscopy (DOS) of water.

PubMed

Chung, S H; Cerussi, A E; Merritt, S I; Ruth, J; Tromberg, B J

2010-07-07

We describe the development of a non-invasive method for quantitative tissue temperature measurements using Broadband diffuse optical spectroscopy (DOS). Our approach is based on well-characterized opposing shifts in near-infrared (NIR) water absorption spectra that appear with temperature and macromolecular binding state. Unlike conventional reflectance methods, DOS is used to generate scattering-corrected tissue water absorption spectra. This allows us to separate the macromolecular bound water contribution from the thermally induced spectral shift using the temperature isosbestic point at 996 nm. The method was validated in intralipid tissue phantoms by correlating DOS with thermistor measurements (R=0.96) with a difference of 1.1+/-0.91 degrees C over a range of 28-48 degrees C. Once validated, thermal and hemodynamic (i.e. oxy- and deoxy-hemoglobin concentration) changes were measured simultaneously and continuously in human subjects (forearm) during mild cold stress. DOS-measured arm temperatures were consistent with previously reported invasive deep tissue temperature studies. These results suggest that DOS can be used for non-invasive, co-registered measurements of absolute temperature and hemoglobin parameters in thick tissues, a potentially important approach for optimizing thermal diagnostics and therapeutics.

The relationship between the Tg depression and the speeding up of physical aging in polystyrene/gold nanocomposites

NASA Astrophysics Data System (ADS)

Boucher, Virginie M.; Cangialosi, Daniele; Alegria, Angel; Colmenero, Juan

2011-03-01

The effect of gold nanoparticles on the segmental dynamics, glass transition (Tg) and physical aging of polystyrene (PS) was studied in PS/Gold nanocomposites samples containing 5 and 15 wt.% of 60 nm spherical gold nanoparticles, surface-treated with thiolated-PS. While the segmental dynamics of PS, as assessed by broadband dielectric spectroscopy (BDS), was found to be unchanged in presence of gold nanoparticles, the calorimetric Tg of PS was shown to decrease with increasing the amount of nanoparticles in the samples. Furthermore, the physical aging of PS, monitored by measuring the enthalpy relaxation below Tg by means of DSC, was shown to speed up with increasing the nanoparticles weight fraction, i.e. the amount of PS/Gold interface in the hybrid material. Thus, the main conclusion of our work is that PS molecular mobility and out-of-equilibrium dynamics are decoupled in these nanocomposites. The significant effect of the amount of PS/Gold interface on both the physical aging rate of PS and the calorimetric Tg depression are quantitatively accounted for by a model based on the diffusion of free volume holes towards polymer interfaces, with a diffusion coefficient depending only on the molecular mobility.

Hybrid model for wireless mobility management using IPv6

NASA Astrophysics Data System (ADS)

Howie, Douglas P.; Sun, Junzhao; Koivisto, Antti T.

2001-07-01

Within the coming decade, there will be a dramatic increase in the availability of inexpensive, computationally powerful mobile devices running applications which use the Internet Protocol (IP) to access multimedia services over broad-band wireless connections. To this end, there has been extensive research and standardization in the areas of Mobile IP and IPv6. The purpose of this paper is to apply this work to the issues involved in designing a mobility model able to adapt to different wireless mobile IP scenarios. We describe the usefulness of this model in the 4th generation mobile multimedia systems to come. This new model has been synthesized through a comparative analysis of current mobile IP models where particular attention has been given to the problems of mobile IP handoff and mobility management and their impact on QoS. By applying a unique perspective to these problems, our model is used to set a roadmap for future mobile IPv6 testbed construction.

Handling imbalance data in churn prediction using combined SMOTE and RUS with bagging method

NASA Astrophysics Data System (ADS)

Pura Hartati, Eka; Adiwijaya; Arif Bijaksana, Moch

2018-03-01

Customer churn has become a significant problem and also a challenge for Telecommunication company such as PT. Telkom Indonesia. It is necessary to evaluate whether the big problems of churn customer and the company’s managements will make appropriate strategies to minimize the churn and retaining the customer. Churn Customer data which categorized churn Atas Permintaan Sendiri (APS) in this Company is an imbalance data, and this issue is one of the challenging tasks in machine learning. This study will investigate how is handling class imbalance in churn prediction using combined Synthetic Minority Over-Sampling (SMOTE) and Random Under-Sampling (RUS) with Bagging method for a better churn prediction performance’s result. The dataset that used is Broadband Internet data which is collected from Telkom Regional 6 Kalimantan. The research firstly using data preprocessing to balance the imbalanced dataset and also to select features by sampling technique SMOTE and RUS, and then building churn prediction model using Bagging methods and C4.5.

Taking mHealth Forward: Examining the Core Characteristics

PubMed Central

2016-01-01

The emergence of mobile health (mHealth) offers unique and varied opportunities to address some of the most difficult problems of health. Some of the most promising and active efforts of mHealth involve the engagement of mobile phone technology. As this technology has spread and as this technology is still evolving, we begin a conversation about the core characteristics of mHealth relevant to any mobile phone platform. We assert that the relevance of these characteristics to mHealth will endure as the technology advances, so an understanding of these characteristics is essential to the design, implementation, and adoption of mHealth-based solutions. The core characteristics we discuss are (1) the penetration or adoption into populations, (2) the availability and form of apps, (3) the availability and form of wireless broadband access to the Internet, and (4) the tethering of the device to individuals. These collectively act to both enable and constrain the provision of population health in general, as well as personalized and precision individual health in particular. PMID:27511612

Fiber-FSO/wireless convergent systems based on dual-polarization and one optical sideband transmission schemes

NASA Astrophysics Data System (ADS)

Huang, Xu-Hong; Lu, Hai-Han; Li, Chung-Yi; Wang, Yun-Chieh; Chang, Jen-Chieh; Jheng, Yu-Bo; Tsai, Wen-Shing

2018-06-01

A bidirectional fiber-free-space optical (FSO)/wireless convergent system that uses dual-polarization and one optical sideband transmission schemes for hybrid vestigial sideband (VSB)–four-level pulse amplitude modulation (PAM4)/millimeter-wave signal transmission is proposed and demonstrated. Using a dual-polarization scheme, one optical sideband that is modulated by a 56 Gb s‑1 VSB–PAM4 signal (x-polarization) and another optical sideband that is modulated by a 10 Gbps data stream (y-polarization) are separated and polarized orthogonally. One optical sideband modulated by a 10 Gbps data stream (y-polarization) is delivered to efficaciously suppress the dispersion-induced limitation due to a span of 40 km single-mode fiber (SMF) and the distortion due to the beating among multiple sidebands. The proposed bidirectional fiber-FSO/wireless convergent system is a prominent one for providing broadband integrated services, such as the Internet, telecommunication, and 5G mobile networks.

On Modeling and Analysis of MIMO Wireless Mesh Networks with Triangular Overlay Topology

DOE PAGES

Cao, Zhanmao; Wu, Chase Q.; Zhang, Yuanping; ...

2015-01-01

Multiple input multiple output (MIMO) wireless mesh networks (WMNs) aim to provide the last-mile broadband wireless access to the Internet. Along with the algorithmic development for WMNs, some fundamental mathematical problems also emerge in various aspects such as routing, scheduling, and channel assignment, all of which require an effective mathematical model and rigorous analysis of network properties. In this paper, we propose to employ Cartesian product of graphs (CPG) as a multichannel modeling approach and explore a set of unique properties of triangular WMNs. In each layer of CPG with a single channel, we design a node coordinate scheme thatmore » retains the symmetric property of triangular meshes and develop a function for the assignment of node identity numbers based on their coordinates. We also derive a necessary-sufficient condition for interference-free links and combinatorial formulas to determine the number of the shortest paths for channel realization in triangular WMNs.« less

Research on the application of softswitch in FTTH

NASA Astrophysics Data System (ADS)

Rui, Yang; Hua, Yan Xian

2005-11-01

Fiber to the home (FTTH) is the technology orientation that people have continuously pursued and explored for 20 years, and it is beginning to make significant strides in the field of high-speed broadband access to the Internet. Due to the carriers' competition, the price of optical devices reduced gradually, FTTH develops very quickly. With the emergence of next generation network (NGN), softswitch plays an important role in the evolvement from PSTN to NGN. The combination of FTTH and softswitch can solve many problems in FTTH applications, which guarantees the evolvement from the existing network to NGN and provides service functions to meet the further requirements of various carriers and customers. This paper mainly introduces the application of softswitch in FTTH, outlines the developing background of FTTH and softswitch, and discusses the voice bearing solution based on FTTH. At last it focuses on the key problems and solutions of the application with the example of the implementation of voice service.

Energy-signal quality trade-offs in a WiMAX mobile station with a booster amplifier

NASA Astrophysics Data System (ADS)

Suherman; Mubarakah, N.; Wiranata, O.; Kasim, S. T.

2018-02-01

Worldwide Interoperability for Microwave Access (WiMAX) is a broadband wireless access technology that is able to provide high bit rate mobile internet services. Battery endurance remains a problem in current mobile communication. On the other hand, signal quality determines the successful run of the mobile applications. Energy consumption optimization cannot sacrifice the signal level required by the application to run smoothly. On the contrary, the application should consider battery life time. This paper examines the tradeoffs between energy and signal quality in WiMAX subscriber station by adjusting signal level using a booster amplifier. Simulation evaluations show that an increment of 0.00000104% energy consumption on using amplifier adaptively produces 16.411% signal to noise ratio (SNR) increment and 10.7% bit error rate (BER) decrement. By keeping the amplifier turned on, energy consumption increases up to 0.00000136%, causing the SNR rises to 17.2638% and BER drops to 11.13%. The evaluated application is video streaming, other application may behave differently.

e-Business Innovation: The Next Decade

NASA Astrophysics Data System (ADS)

Marca, David A.

Innovation is invention or application of technologies or theories that radically alters business and the economy. For many years, innovation and the economy have been locked in 80-year cycles, which might imply that innovation is an economic driver, and vice versa. Based on this, some forecast that innovation and the economy might decrease sharply due to several forces: a) decreasing economic growth, b) increasing demand for custom services, c) more entrepreneurial work environments, and d) urban and environmental degradation. Should such forecasts hold true, business may need to alter its offerings, operations and organization to survive. Such a scenario may also require applied e-Business innovation by combining existing internet, wireless, broadband, and video technologies. One possible result: flexible front offices integrated with efficient back offices. Such an e-Business could comprise: a) a customer-based and transaction-based organization, b) functions for adaptive offerings that anticipate need, c) highly responsive, real-time, operations having no inventory, and d) value-based front-end, and automated back-end, decision making.

Chemical effect on diffusion in intermetallic compounds

NASA Astrophysics Data System (ADS)

Chen, Yi-Ting

With the trend of big data and the Internet of things, we live in a world full of personal electronic devices and small electronic devices. In order to make the devices more powerful, advanced electronic packaging such as wafer level packaging or 3D IC packaging play an important role. Furthermore, ?-bumps, which connect silicon dies together with dimension less than 10 ?m, are crucial parts in advanced packaging. Owing to the dimension of ?-bumps, they transform into intermetallic compound from tin based solder after the liquid state bonding process. Moreover, many new reliability issues will occur in electronic packaging when the bonding materials change; in this case, we no longer have tin based solder joint, instead, we have intermetallic compound ?-bumps. Most of the potential reliability issues in intermetallic compounds are caused by the chemical reactions driven by atomic diffusion in the material; thus, to know the diffusivities of atoms inside a material is significant and can help us to further analyze the reliability issues. However, we are lacking these kinds of data in intermetallic compound because there are some problems if used traditional Darken's analysis. Therefore, we considered Wagner diffusivity in our system to solve the problems and applied the concept of chemical effect on diffusion by taking the advantage that large amount of energy will release when compounds formed. Moreover, by inventing the holes markers made by Focus ion beam (FIB), we can conduct the diffusion experiment and obtain the tracer diffusivities of atoms inside the intermetallic compound. We applied the technique on Ni3Sn4 and Cu3Sn, which are two of the most common materials in electronic packaging, and the tracer diffusivities are measured under several different temperatures; moreover, microstructure of the intermetallic compounds are investigated to ensure the diffusion environment. Additionally, the detail diffusion mechanism was also discussed in aspect of diffusion activation enthalpy and diffusion pre-factor by using lattice structure simulation. Last but not the least, X-ray photoelectron spectroscopy and First principal calculation simulation were used to observe the electron binding energies in the intermetallic compound and illustrate the partial covalent bonding behavior in the intermetallic compounds.

On the suitability of broadband attenuation measurement for characterizing contrast microbubbles.

PubMed

Chatterjee, Dhiman; Sarkar, Kausik; Jain, Pankaj; Schreppler, Nathan E

2005-06-01

Broadband attenuation measurement has been widely used for characterizing ultrasound contrast agents. Chen et al. (2002) recently suggested that broadband attenuation data depend on the center frequency of the broadband excitation pulse and, therefore, that they are not a reliable measure of the bubble behavior. We investigated the suitability of measurement of broadband attenuation as a characterizing tool using the contrast agent Definity as a test case. Analyzing the attenuation data obtained with three broadband unfocused transducers with different center frequencies (2.25, 3.5 and 5 MHz), we found that attenuation is independent of the transducer used and matches in the overlap regions of any two transducers. Attenuation does not depend on excitation pressure amplitude as long as the excitation amplitude remains below a critical value ( approximately 0.26 MPa), indicating that the measurement of broadband attenuation below critical excitation can, indeed, be used for characterization. Furthermore, the linear relationship of attenuation with concentrations of Definity is also investigated.

Chaos-assisted broadband momentum transformation in optical microresonators.

PubMed

Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

2017-10-20

The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Atlantic bottlenose dolphin (Tursiops truncatus) hearing threshold for brief broadband signals.

PubMed

Au, Whitlow W L; Lemonds, David W; Vlachos, Stephanie; Nachtigall, Paul E; Roitblat, Herbert L

2002-06-01

The hearing sensitivity of an Atlantic bottlenose dolphin (Tursiops truncatus) to both pure tones and broadband signals simulating echoes from a 7.62-cm water-filled sphere was measured. Pure tones with frequencies between 40 and 140 kHz in increments of 20 kHz were measured along with broadband thresholds using a stimulus with a center frequency of 97.3 kHz and 88.2 kHz. The pure-tone thresholds were compared with the broadband thresholds by converting the pure-tone threshold intensity to energy flux density. The results indicated that dolphins can detect broadband signals slightly better than a pure-tone signal. The broadband results suggest that an echolocating bottlenose dolphin should be able to detect a 7.62-cm diameter water-filled sphere out to a range of 178 m in a quiet environment.

Broadband Liner Optimization for the Source Diagnostic Test Fan

NASA Technical Reports Server (NTRS)

Nark, Douglas M.; Jones, Michael G.

2012-01-01

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

Making structured metals transparent for ultrabroadband electromagnetic waves and acoustic waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, Ren-Hao; Peng, Ru-Wen, E-mail: rwpeng@nju.edu.cn; Huang, Xian-Rong

2015-07-15

In this review, we present our recent work on making structured metals transparent for broadband electromagnetic waves and acoustic waves via excitation of surface waves. First, we theoretically show that one-dimensional metallic gratings can become transparent and completely antireflective for extremely broadband electromagnetic waves by relying on surface plasmons or spoof surface plasmons. Second, we experimentally demonstrate that metallic gratings with narrow slits are highly transparent for broadband terahertz waves at oblique incidence and high transmission efficiency is insensitive to the metal thickness. Further, we significantly develop oblique metal gratings transparent for broadband electromagnetic waves (including optical waves and terahertzmore » ones) under normal incidence. In the third, we find the principles of broadband transparency for structured metals can be extended from one-dimensional metallic gratings to two-dimensional cases. Moreover, similar phenomena are found in sonic artificially metallic structures, which present the transparency for broadband acoustic waves. These investigations provide guidelines to develop many novel materials and devices, such as transparent conducting panels, antireflective solar cells, and other broadband metamaterials and stealth technologies. - Highlights: • Making structured metals transparent for ultrabroadband electromagnetic waves. • Non-resonant excitation of surface plasmons or spoof surface plasmons. • Sonic artificially metallic structures transparent for broadband acoustic waves.« less

75 FR 6627 - Broadband Technology Opportunities Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-10

... DEPARTMENT OF COMMERCE National Telecommunications and Information Administration [Docket No. 0907141137-0079-07] RIN 0660-ZA28 Broadband Technology Opportunities Program AGENCY: National... policy and application procedures for the Broadband Technology Opportunities Program (BTOP) established...

Making structured metals transparent for ultrabroadband electromagnetic waves and acoustic waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, Ren-Hao; Peng, Ru-Wen; Huang, Xian-Rong

2015-07-01

In this review, we present our recent work on making structured metals transparent for broadband electromagnetic waves and acoustic waves via excitation of surface waves. First, we theoretically show that one-dimensional metallic gratings can become transparent and completely antireflective for extremely broadband electromagnetic waves by relying on surface plasmons or spoof surface plasmons. Second, we experimentally demonstrate that metallic gratings with narrow slits are highly transparent for broadband terahertz waves at oblique incidence and high transmission efficiency is insensitive to the metal thickness. Further, we significantly develop oblique metal gratings transparent for broadband electromagnetic waves (including optical waves and terahertzmore » ones) under normal incidence. In the third, we find the principles of broadband transparency for structured metals can be extended from one-dimensional metallic gratings to two-dimensional cases. Moreover, similar phenomena are found in sonic artificially metallic structures, which present the transparency for broadband acoustic waves. These investigations provide guidelines to develop many novel materials and devices, such as transparent conducting panels, antireflective solar cells, and other broadband metamaterials and stealth technologies.« less

Distance reporting in digital pathology: A study on 950 cases

PubMed Central

Vodovnik, Aleksandar

2015-01-01

Background: Increased workload, case complexity, financial constraints, and staffing shortages justify wider implementations of digital pathology. One of its main advantages is distance reporting. Aim: A feasibility study was conducted at our institution in order to achieve comprehensive pathology services available by distance. Methods: One senior pathologist reported 950 cases (3,650 slides) by distance during 19 weeks. Slides were scanned by ScanScope AT Turbo (Aperio) and digital images accessed through SymPathy (Tieto) on a 14” laptop. Mobile phone, mobile broadband, broadband over Wi-Fi and broadband were used for internet connections along with a virtual private network technology (VPN). Lync (Microsoft) was tested for one case consultation and resident's teaching session. Larger displays were accessed when available. Effects of ergonomics and working flexibility on the user experience were observed. Details on network speed, frequency of technical issues, data usage, scanning, and turnaround, were collected and evaluated. Turnaround was compared to in-office microscopic reporting, measured from the registration to sign off. Results: Network speeds varied 1–80 Mbps (median download speed 8–65 Mbps). 20 Mbps were satisfactory for the instant upload of digital images. VPN, image viewer, and laptop failed on two occasions each. An estimated data usage per digital image was 10 MB (1–50 MB). Two cases (15 slides) were deferred to microscopic slides (0.21/0.41%) due to scanty material and suboptimal slide quality. Additional nine cases (15 slides) needed to be rescanned for various reasons (0.95/0.41%). Average turnaround was shorter, and the percentage of cases reported up to 3 days higher (3.13 days/72.25%) comparing with in-office microscopic reporting (3.90 days/40.56%). Larger displays improved the most user experience at magnifications over ×20. Conclusions: Existing IT solutions at our institution allow efficient and reliable distance reporting for the core pathology services in histology and cytology. Stable network speeds, fully integrated laboratory information management system, technical reliability, working flexibility, larger displays, and shorter turnaround contributed to the overall satisfaction with distance reporting. A further expansion of our pathology services available by distance, diagnostic and educational, rely on gaining experience in digital reporting and marginal IT investment. Adjustments to the organization of pathology services may follow to fully benefit from the implementation of digital pathology. PMID:25969793

Distance reporting in digital pathology: A study on 950 cases.

PubMed

Vodovnik, Aleksandar

2015-01-01

Increased workload, case complexity, financial constraints, and staffing shortages justify wider implementations of digital pathology. One of its main advantages is distance reporting. A feasibility study was conducted at our institution in order to achieve comprehensive pathology services available by distance. One senior pathologist reported 950 cases (3,650 slides) by distance during 19 weeks. Slides were scanned by ScanScope AT Turbo (Aperio) and digital images accessed through SymPathy (Tieto) on a 14" laptop. Mobile phone, mobile broadband, broadband over Wi-Fi and broadband were used for internet connections along with a virtual private network technology (VPN). Lync (Microsoft) was tested for one case consultation and resident's teaching session. Larger displays were accessed when available. Effects of ergonomics and working flexibility on the user experience were observed. Details on network speed, frequency of technical issues, data usage, scanning, and turnaround, were collected and evaluated. Turnaround was compared to in-office microscopic reporting, measured from the registration to sign off. Network speeds varied 1-80 Mbps (median download speed 8-65 Mbps). 20 Mbps were satisfactory for the instant upload of digital images. VPN, image viewer, and laptop failed on two occasions each. An estimated data usage per digital image was 10 MB (1-50 MB). Two cases (15 slides) were deferred to microscopic slides (0.21/0.41%) due to scanty material and suboptimal slide quality. Additional nine cases (15 slides) needed to be rescanned for various reasons (0.95/0.41%). Average turnaround was shorter, and the percentage of cases reported up to 3 days higher (3.13 days/72.25%) comparing with in-office microscopic reporting (3.90 days/40.56%). Larger displays improved the most user experience at magnifications over ×20. Existing IT solutions at our institution allow efficient and reliable distance reporting for the core pathology services in histology and cytology. Stable network speeds, fully integrated laboratory information management system, technical reliability, working flexibility, larger displays, and shorter turnaround contributed to the overall satisfaction with distance reporting. A further expansion of our pathology services available by distance, diagnostic and educational, rely on gaining experience in digital reporting and marginal IT investment. Adjustments to the organization of pathology services may follow to fully benefit from the implementation of digital pathology.

Optical depth retrievals from Delta-T SPN1 measurements of broadband solar irradiance at ground

NASA Astrophysics Data System (ADS)

Estelles, Victor; Serrano, David; Segura, Sara; Wood, John; Webb, Nick

2016-04-01

The SPN1 radiometer, manufactured by Delta-T Devices Ltd., is an instrument designed for the measurement of global solar irradiance and its components (diffuse, direct) at ground level. In the present study, the direct irradiance component has been used to retrieve an effective total optical depth, by applying the Beer-Lambert law to the broadband measurements. The results have been compared with spectral total optical depths derived from two Cimel CE318 and Prede POM01 sun-sky radiometers, located at the Burjassot site in Valencia (Spain), during years 2013 - 2015. The SPN1 is an inexpensive and versatile instrument for the measurement of the three components of the solar radiation without any mobile part and without any need to azimuthally align the instrument to track the sun (http://www.delta-t.co.uk). The three components of the solar radiation are estimated from a combination of measurements performed by 7 different miniature thermopiles. In turn, the Beer-Lambert law has been applied to the broadband direct solar component to obtain an effective total optical depth, representative of the total extinction in the atmosphere. For the assessment of the total optical depth values retrieved with the SPN1, two different sun-sky radiometers (Cimel CE318 and Prede POM01L) have been employed. Both instruments belong to the international networks AERONET and SKYNET. The modified SUNRAD package has been applied in both Cimel and Prede instruments. Cloud affected data has been removed by applying the Smirnov cloud-screening procedure in the SUNRAD algorithm. The broadband SPN1 total optical depth has been analysed by comparison with the spectral total optical depth from the sun-sky radiometer measurements at wavelengths 440, 500, 675, 870 and 1020 nm. The slopes and intercepts have been estimated to be 0.47 - 0.98 and 0.055 - 0.16 with increasing wavelength. The average correlation coefficients and RMSD were 0.80 - 0.83 and 0.034 - 0.036 for all the channels. The analysis shows that the SPN1 instrument underestimates the TOD increasingly with wavelength, for higher TOD. This observation is in agreement with the already known effect of a larger effective field of view in the SPN1, as the aureole radiation increase. In any case, these results are promising and would be useful as a determination of the total atmospheric extinction, mainly for users of the SPN1 in the solar radiation field.

Sharing Health Information and Influencing Behavioral Intentions: The Role of Health Literacy, Information Overload, and the Internet in the Diffusion of Healthy Heart Information.

PubMed

Crook, Brittani; Stephens, Keri K; Pastorek, Angie E; Mackert, Michael; Donovan, Erin E

2016-01-01

Low health literacy remains an extremely common and problematic issue, given that individuals with lower health literacy are more likely to experience health challenges and negative health outcomes. In this study, we use the first three stages of the innovation-decision process found in the theory of diffusion of innovations (Rogers, 2003). We incorporate health literacy into a model explaining how perceived health knowledge, information sharing, attitudes, and behavior are related. Results show that health information sharing explains 33% of the variance in behavioral intentions, indicating that the communicative practice of sharing information can positively impact health outcomes. Further, individuals with high health literacy tend to share less information about heart health than those with lower health literacy. Findings also reveal that perceived heart-health knowledge operates differently than health literacy to predict health outcomes.

Techno Generation: Social Networking amongst Youth in South Africa

NASA Astrophysics Data System (ADS)

Basson, Antoinette; Makhasi, Yoliswa; van Vuuren, Daan

Internet and cell phones can be considered as new media compared to traditional media types and have become a fundamental part of the lives of many young people across the globe. The exploratory research study investigated the diffusion and adoption of new media innovations among adolescents. It was found that new media have diffused at a high rate among South African adolescents who are not only the innovators in this area, but also changing their life styles to adapt to the new media. Social networking grew to prominence in South Africa especially among the youth. The protection of children from potential harmful exposure and other risks remain a concern and adequate measures need to be initiated and implemented for children to enjoy social networks and other forms of new media. The exploratory research study provided worthwhile and interesting insights into the role of the new media, in the lives of adolescents in South Africa.

75 FR 10464 - Broadband Technology Opportunities Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... DEPARTMENT OF COMMERCE National Telecommunications and Information Administration [Docket Number 0907141137-0119-08] RIN 0660-ZA28 Broadband Technology Opportunities Program AGENCY: National... Infrastructure (CCI) projects under the Broadband Technology Opportunities Program (BTOP) is extended until 5:00...

75 FR 14131 - Broadband Technology Opportunities Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... DEPARTMENT OF COMMERCE National Telecommunications and Information Administration [Docket Number: 0907141137-0154-09] RIN 0660-ZA28 Broadband Technology Opportunities Program AGENCY: National... under the Broadband Technology Opportunities Program (BTOP) is extended until 10 p.m. Eastern Daylight...

A mixed-modem approach to data isolation on a broadband local area network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crutcher, R.I.; Ewing, P.D.

1988-01-01

Data isolation is required to broadband networks to prevent unauthorized access to the sensitive data of other users. Isolation can be obtained by using equipment from more than one manufacturer to introduce incompatibility between nonassociated users. This paper develops the basis for isolation and postulates that four layers of isolation will exist when the proper equipment is chosen. An experimental broadband local area network (LAN) was constructed to verify isolation. This independent network allowed variations in operating conditions without causing interference in normal broadband operations. The measured results indicate that a broadband LAN can transmit data of varying sensitivity levelsmore » without compromising data security. When combined with certain administrative restrictions, the mixed-modem technique provides a cost-effective method of sharing a broadband network while maintaining isolation of data having different sensitivities. 5 refs., 2 figs.« less

A mixed-modem solution for sensitive data segregation on a broadband network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crutcher, R.I.; Ewing, P.D.

1988-01-01

Data isolation is required in broadband networks to prevent unauthorized access to the sensitive data of other users. Isolation can be obtained by using equipment from different manufacturers to introduce incompatibility between nonassociated users. This paper develops the basis for isolation and postulates that four layers of ioslation will exist when the proper equipment is chosen. An experimental broadband local area network (LAN) was constructed to verify isolation. This independent test system allowed variations to network operating conditions without causing interference to normal broadband operations. The measured results indicate that a broadband LAN can transmit data of varying sensitivity levelsmore » without compromising data security. When combined with the proper administrative restrictions, the mixed-modem technique provides a cost-effective method of sharing a broadband network while maintaining isolation of data having different sensitivities. 6 refs., 3 figs.« less

A study of rotor broadband noise mechanisms and helicopter tail rotor noise

NASA Technical Reports Server (NTRS)

Chou, Shau-Tak Rudy

1990-01-01

The rotor broadband noise mechanisms considered are the following: (1) lift fluctuation due to turbulence ingestion; (2) boundary layer/trailing edge interaction; (3) tip vortex formation; and (4) turbulent vortex shedding from blunt trailing edge. Predictions show good agreement with available experimental data. The study shows that inflow turbulence is the most important broadband noise source for typical helicopters' main rotors at low- and mid-frequencies. Due to the size difference, isolated helicopter tail rotor broadband noise is not important compared to the much louder main rotor broadband noise. However, the inflow turbulence noise from a tail rotor can be very significant because it is operating in a highly turbulent environment, ingesting wakes from upstream components of the helicopter. The study indicates that the main rotor turbulent wake is the most important source of tail rotor broadband noise. The harmonic noise due to ingestion of main rotor tip vortices is studied.

Vaccine-criticism on the internet: new insights based on French-speaking websites.

PubMed

Ward, Jeremy K; Peretti-Watel, Patrick; Larson, Heidi J; Raude, Jocelyn; Verger, Pierre

2015-02-18

The internet is playing an increasingly important part in fueling vaccine related controversies and in generating vaccine hesitant behaviors. English language Antivaccination websites have been thoroughly analyzed, however, little is known of the arguments presented in other languages on the internet. This study presents three types of results: (1) Authors apply a time tested content analysis methodology to describe the information diffused by French language vaccine critical websites in comparison with English speaking websites. The contents of French language vaccine critical websites are very similar to those of English language websites except for the relative absence of moral and religious arguments. (2) Authors evaluate the likelihood that internet users will find those websites through vaccine-related queries on a variety of French-language versions of google. Queries on controversial vaccines generated many more vaccine critical websites than queries on vaccination in general. (3) Authors propose a typology of vaccine critical websites. Authors distinguish between (a) websites that criticize all vaccines ("antivaccine" websites) and websites that criticize only some vaccines ("vaccine-selective" websites), and between (b) websites that focus on vaccines ("vaccine-focused" websites) and those for which vaccines were only a secondary topic of interest ("generalist" websites). The differences in stances by groups and websites affect the likelihood that they will be believed and by whom. This study therefore helps understand the different information landscapes that may contribute to the variety of forms of vaccine hesitancy. Public authorities should have better awareness and understanding of these stances to bring appropriate answers to the different controversies about vaccination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Broad-band emission properties of central engine powered supernova ejecta interacting with a circumstellar medium

NASA Astrophysics Data System (ADS)

Suzuki, Akihiro; Maeda, Keiichi

2018-04-01

We investigate broad-band emission from supernova ejecta powered by a relativistic wind from a central compact object. A recent two-dimensional hydrodynamic simulation studying the dynamical evolution of supernova ejecta with a central energy source has revealed that outermost layers of the ejecta are accelerated to mildly relativistic velocities because of the breakout of a hot bubble driven by the energy injection. The outermost layers decelerate as they sweep a circumstellar medium surrounding the ejecta, leading to the formation of the forward and reverse shocks propagating in the circumstellar medium and the ejecta. While the ejecta continue to release the internal energy as thermal emission from the photosphere, the energy dissipation at the forward and reverse shock fronts gives rise to non-thermal emission. We calculate light curves and spectral energy distributions of thermal and non-thermal emission from central engine powered supernova ejecta embedded in a steady stellar wind with typical mass loss rates for massive stars. The light curves are compared with currently available radio and X-ray observations of hydrogen-poor superluminous supernovae, as well as the two well-studied broad-lined Ic supernovae, 1998bw and 2009bb, which exhibit bright radio emission indicating central engine activities. We point out that upper limits on radio luminosities of nearby superluminous supernovae may indicate the injected energy is mainly converted to thermal radiation rather than creating mildly relativistic flows owing to photon diffusion time scales comparable to the injection time scale.

Characteristics of a Broadband Dye Laser Using Pyrromethene and Rhodamine Dyes

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Danehy, Paul M.; Wheeler, Jeffrey L.

2011-01-01

A broadband dye laser pumped by a frequency-doubled Nd:YAG laser with a full-width half-maximum (FWHM) from 592 to 610 nm was created for the use in a dual-pump broadband CARS system called WIDECARS. The desired broadband dye laser was generated with a mixture of Pyrromethene dyes as an oscillator gain medium and a spectral selective optic in the oscillator cavity. A mixture of Rhodamine dyes were used in the amplifier dye cell. To create this laser a study was performed to characterize the spectral behavior of broadband dye lasers created with Rhodamine dyes 590, 610, and 640, Pyrromethene dyes 597 and 650 as well as mixture of these dyes.

Evaluation of introduction scenarios for a broadband access network

NASA Astrophysics Data System (ADS)

Bocker, Geert-Jan; Cuthbert, Laurie; Gobbi, Roberta; Inch, Robert; Sara, Lini

1995-02-01

The provision of broadband services at a reasonable cost to residential and small business customers is one of the major challenges facing operators. The introduction of cost-effective systems considering the existing infrastructure is an important study. Within the RACE project 2024 Broadband Access Facilities, the economic and evolution aspects of different introduction scenarios of a broadband access system suitable for providing these services are investigated. This paper presents the final results of this study.

Broadband optical equalizer using fault tolerant digital micromirrors.

PubMed

Riza, Nabeel; Mughal, M Junaid

2003-06-30

For the first time, the design and demonstration of a near continuous spectral processing mode broadband equalizer is described using the earlier proposed macro-pixel spatial approach for multiwavelength fiber-optic attenuation in combination with a high spectral resolution broadband transmissive volume Bragg grating. The demonstrated design features low loss and low polarization dependent loss with broadband operation. Such an analog mode spectral processor can impact optical applications ranging from test and instrumentation to dynamic alloptical networks.

Metropolitan area networks: a corner stone in the broadband era

NASA Astrophysics Data System (ADS)

Ghanem, Adel

1991-02-01

Deployment of Broadband ISDN is being influenced by both a market pull and a technology push. New broadband service opportunities exist in the business and residential sectors of the market place. It is envisioned that some customers will need connections directly to broadband switches because of the high bandwidth needed for their applications. At the same time Metropolitan Area Network (MAN) systems will serve those customers with bandwidth requirements less than or equal to 150 Mbps. A given MAN will have a geographical domain to serve where it will carry out the switching tasks within this domain. While MANs couldbe designed using differentarchitecturalconcepts the setofservices expected tobeprovidedby MANs could be equivalent to thelist ofservices thatwillbe supported by the targetbroadband network. This paperpositions MANs as a major building block for Broadband networks. It also examines the evolution process ofMANs as a needed step to assure the successful deployment of these new broadband services. 2. BISDN - OVERVIEW Broadband ISDN (BISDN) is being driven into existence by both a market pull as well as a technology push. Opportunities for new valueadded services are the prime market pull for future broadband networks. These services opportunities extend beyond simple voice and low speed data applications and cover both the residential and the business sectors of the market. It is noted for instance that business customers have growing needs for sophisticated telecommunication vehicles to support their

Lightweight multi-carrier modulation for IoT

NASA Astrophysics Data System (ADS)

Hussein, Ahmed F.; Elgala, Hany

2018-01-01

Visible light communications (VLC) based on intensity-modulation with direct-detection (IM/DD) is a promising technology to offer broadband wireless Internet access. A VLC system based on the well-known multi-carrier orthogonal frequency-division multiplexing (OFDM) modulation has the potential to coexist with radio frequency (RF) technologies such as WiFi. Recently, the VLC technology is considered to enable wireless connectivity of resource limited devices, thus enabling the Internet-of-Things (IoT) vision. This paper presents a novel concept for modulating multiple light sources to realize a lightweight version of OFDM communication chain suitable for resource limited IoT devices. In such proposed system, different sinusoidal streams from an array of light sources are carrying the encoded OFDM time-domain samples, thus enabling the realization of the Fourier transformation in the optical domain. Accordingly, the fast Fourier transform (FFT) operation required for the demodulation at the receiver side is eliminated, which is crucial for resource limited IoT devices. In addition, the proposed concept, (1) offers the same spectral efficiency as the well-known asymmetrically clipped optical OFDM (ACO-OFDM), (2) reduces the bandwidth requirement from individual light sources, (3) reduces the peak-to-average power ratio (PAPR) of the signal formed and transmitted over the optical channel, and (4) supports simultaneous sensing applications using the different sinusoidal streams that are acting as unique beaconing signals. The proposed concept is numerically evaluated and compared with ACO-OFDM. The obtained results reveal a clear reduction in the PAPR with ˜ 5dB at a complementary cumulative distribution function (CCDF) of 10-2 and remarkable enhancement in bit-error performance.

Radiofrequency electromagnetic radiation exposure inside the metro tube infrastructure in Warszawa.

PubMed

Gryz, Krzysztof; Karpowicz, Jolanta

2015-09-01

Antennas from various wireless communications systems [e.g. mobile phones base transceiver stations (BTS) and handsets used by passengers, public Internet access, staff radiophone transmitters used between engine-drivers and traffic operators] emitting radiofrequency electromagnetic radiation (RF-EMR) are used inside underground metro public transportation. Frequency-selective exposimetric investigations of RF-EMR exposure inside the metro infrastructure in Warsaw (inside metro cars passing between stations and on platforms) were performed. The statistical parameters of exposure to the E-field were analyzed for each frequency range and for a total value (representing the wide-band result of measurements of complex exposure). The recorded exposimetric profiles showed the dominant RF-EMR sources: handsets and BTS of mobile communication systems (GSM 900 and UMTS 2100) and local wireless Internet access (WiFi 2G). Investigations showed that the GSM 900 system is the dominant source of exposure - BTS (incessantly active) on platforms, and handsets - used by passengers present nearby during the tube drive. The recorded E-field varies between sources (for BTS were: medians - 0.22 V/m and 75th percentile - 0.37 V/m; and for handsets: medians - 0.28 V/m and 75th percentile - 0.47 V/m). Maximum levels (peaks) of exposure recorded from mobile handsets exceeded 10 V/m (upper limit of used exposimeters). Broadband measurements of E-field, including the dominant signal emitted by staff radiophones (151 MHz), showed that the level of this exposure of engine-drivers does not exceed 2.5 V/m.

Advances Made in the Next Generation of Satellite Networks

NASA Technical Reports Server (NTRS)

Bhasin, Kul B.

1999-01-01

Because of the unique networking characteristics of communications satellites, global satellite networks are moving to the forefront in enhancing national and global information infrastructures. Simultaneously, broadband data services, which are emerging as the major market driver for future satellite and terrestrial networks, are being widely acknowledged as the foundation for an efficient global information infrastructure. In the past 2 years, various task forces and working groups around the globe have identified pivotal topics and key issues to address if we are to realize such networks in a timely fashion. In response, industry, government, and academia undertook efforts to address these topics and issues. A workshop was organized to provide a forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. The Satellite Networks: Architectures, Applications, and Technologies Workshop was hosted by the Space Communication Program at the NASA Lewis Research Center in Cleveland, Ohio. Nearly 300 executives and technical experts from academia, industry, and government, representing the United States and eight other countries, attended the event (June 2 to 4, 1998). The program included seven panels and invited sessions and nine breakout sessions in which 42 speakers presented on technical topics. The proceedings covers a wide range of topics: access technology and protocols, architectures and network simulations, asynchronous transfer mode (ATM) over satellite networks, Internet over satellite networks, interoperability experiments and applications, multicasting, NASA interoperability experiment programs, NASA mission applications, and Transmission Control Protocol/Internet Protocol (TCP/IP) over satellite: issues, relevance, and experience.

IA-Regional-Radio - Social Network for Radio Recommendation

NASA Astrophysics Data System (ADS)

Dziczkowski, Grzegorz; Bougueroua, Lamine; Wegrzyn-Wolska, Katarzyna

This chapter describes the functions of a system proposed for the music hit recommendation from social network data base. This system carries out the automatic collection, evaluation and rating of music reviewers and the possibility for listeners to rate musical hits and recommendations deduced from auditor's profiles in the form of regional Internet radio. First, the system searches and retrieves probable music reviews from the Internet. Subsequently, the system carries out an evaluation and rating of those reviews. From this list of music hits, the system directly allows notation from our application. Finally, the system automatically creates the record list diffused each day depending on the region, the year season, the day hours and the age of listeners. Our system uses linguistics and statistic methods for classifying music opinions and data mining techniques for recommendation part needed for recorded list creation. The principal task is the creation of popular intelligent radio adaptive on auditor's age and region - IA-Regional-Radio.

Bright-White Beetle Scales Optimise Multiple Scattering of Light

NASA Astrophysics Data System (ADS)

Burresi, Matteo; Cortese, Lorenzo; Pattelli, Lorenzo; Kolle, Mathias; Vukusic, Peter; Wiersma, Diederik S.; Steiner, Ullrich; Vignolini, Silvia

2014-08-01

Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index scattering centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense scattering media. Using time-resolved measurements, we show that light propagating in the scales of the beetles undergoes pronounced multiple scattering that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our light transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure.

Influences of Models on the Unsteady Pressure Characteristics of the NASA National Transonic Facility

NASA Technical Reports Server (NTRS)

Jones, Gregory; Balakrishna, Sundareswara; DeMoss, Joshua; Goodliff, Scott; Bailey, Matthew

2015-01-01

Pressure fluctuations have been measured over the course of several tests in the National Transonic Facility to study unsteady phenomenon both with and without the influence of a model. Broadband spectral analysis will be used to characterize the length scales of the tunnel. Special attention will be given to the large-scale, low frequency data that influences the Mach number and force and moment variability. This paper will also discuss the significance of the vorticity and sound fields that can be related to the Common Research Model and will also highlight the comparisons to an empty tunnel configuration. The effectiveness of vortex generators placed at the interface of the test section and wind tunnel diffuser showed promise in reducing the empty tunnel unsteadiness, however, the vortex generators were ineffective in the presence of a model.

47 CFR 27.1203 - EBS programming requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27... Broadband Service stations are intended primarily through video, data, or voice transmissions to further the... endeavors; (2) Transmission of material directly related to the administrative activities of the licensee...

Broadband Pillbox Antennas.

DTIC Science & Technology

1984-09-21

Identify by block number) - FIELD GROUP SUB-GROUP Double layer pillbox antennas Triple layer pillbox antenna The possibility of designing very broadband... Design .................... 1 Broadband Feed De gn ........................................... 2 Ex mental Simulation of Double Layer Pillbox...5 REFERENCES ................................................... 6 APPENDIX - COAXIAL TO WAVEGUIDE JUNCTION DESIGN

Broadband radiometric LED measurements

NASA Astrophysics Data System (ADS)

Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

2016-09-01

At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

BREAD: a European coordination action for broadband for all

NASA Astrophysics Data System (ADS)

Van Daele, P.

2006-10-01

The BREAD - co-ordination action, funded by the European Commission through the Framework 6 Programme (FP6) aims at developing a multi-disciplinary approach for the realization of the 'Broadband for All' concept within Europe, bringing together societal, economic, regulatory and technological disciplines and presenting information from regional "success stories" of actual deployment. The EU objective of achieving "Broadband for All" will not be reached by solely a 'technology push' strategy but will need this multi-disciplinary approach and sharing of views and knowledge to develop new strategies and good practice recommendations in the area of 'Broadband for All'. As a co-ordination action the project wants to unite all players active in the field of the end-to-end broadband provisioning for all. It performs a multi-technological analysis of the current and evolving situation, starting from the roadmap information generated by different projects and IST instruments which focus on specific technological domains. The BREAD consortium simultaneously studies the techno-economic, societal and regulatory aspects of this "Broadband for All" concept. It tries to identify the impact of the EU regulatory framework on the successful implementation of new broadband communication services.

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

Dielectric Loaded Broadband Gyro-TWT System

DTIC Science & Technology

1993-12-31

A•wov•] f~ •ubic re] ease ;a AD-A277 889 -4 LLV t Final Report 01 Jan 92 - 31 Dec 93 DIELECTRIC LOADED BROADBAND GYRO- TWT SYSTEM Professor N. C...Loaded Broadband Gyro- TWT System" CONTRACT / GRANT NO.: F49620-92-J-O 175 CONTRACT / GRANT VALUE: $89,816 Acce’son For CONTRACT / GRANT PERIOD OF... Broadband Dielectric-Loaded Gyro- TWT Amplifier," submitted for publication to Physics Review Letters, October, 1993. A. Gover, F.V. Hartemann, G.P. Le

Refinements to the Graves and Pitarka (2010) Broadband Ground-Motion Simulation Method

DOE PAGES

Graves, Robert; Pitarka, Arben

2014-12-17

This brief article describes refinements to the Graves and Pitarka (2010) broadband ground-motion simulation methodology (GP2010 hereafter) that have been implemented in version 14.3 of the Southern California Earthquake Center (SCEC) Broadband Platform (BBP). The updated version of our method on the current SCEC BBP is referred to as GP14.3. Here, our simulation technique is a hybrid approach that combines low- and high-frequency motions computed with different methods into a single broadband response.

The SCEC Broadband Platform: A Collaborative Open-Source Software Package for Strong Ground Motion Simulation and Validation

NASA Astrophysics Data System (ADS)

Silva, F.; Maechling, P. J.; Goulet, C.; Somerville, P.; Jordan, T. H.

2013-12-01

The Southern California Earthquake Center (SCEC) Broadband Platform is a collaborative software development project involving SCEC researchers, graduate students, and the SCEC Community Modeling Environment. The SCEC Broadband Platform is open-source scientific software that can generate broadband (0-100Hz) ground motions for earthquakes, integrating complex scientific modules that implement rupture generation, low and high-frequency seismogram synthesis, non-linear site effects calculation, and visualization into a software system that supports easy on-demand computation of seismograms. The Broadband Platform operates in two primary modes: validation simulations and scenario simulations. In validation mode, the Broadband Platform runs earthquake rupture and wave propagation modeling software to calculate seismograms of a historical earthquake for which observed strong ground motion data is available. Also in validation mode, the Broadband Platform calculates a number of goodness of fit measurements that quantify how well the model-based broadband seismograms match the observed seismograms for a certain event. Based on these results, the Platform can be used to tune and validate different numerical modeling techniques. During the past year, we have modified the software to enable the addition of a large number of historical events, and we are now adding validation simulation inputs and observational data for 23 historical events covering the Eastern and Western United States, Japan, Taiwan, Turkey, and Italy. In scenario mode, the Broadband Platform can run simulations for hypothetical (scenario) earthquakes. In this mode, users input an earthquake description, a list of station names and locations, and a 1D velocity model for their region of interest, and the Broadband Platform software then calculates ground motions for the specified stations. By establishing an interface between scientific modules with a common set of input and output files, the Broadband Platform facilitates the addition of new scientific methods, which are written by earth scientists in a number of languages such as C, C++, Fortran, and Python. The Broadband Platform's modular design also supports the reuse of existing software modules as building blocks to create new scientific methods. Additionally, the Platform implements a wrapper around each scientific module, converting input and output files to and from the specific formats required (or produced) by individual scientific codes. Working in close collaboration with scientists and research engineers, the SCEC software development group continues to add new capabilities to the Broadband Platform and to release new versions as open-source scientific software distributions that can be compiled and run on many Linux computer systems. Our latest release includes the addition of 3 new simulation methods and several new data products, such as map and distance-based goodness of fit plots. Finally, as the number and complexity of scenarios simulated using the Broadband Platform increase, we have added batching utilities to substantially improve support for running large-scale simulations on computing clusters.

Internet-to-orbit gateway and virtual ground station: A tool for space research and scientific outreach

NASA Astrophysics Data System (ADS)

Jaffer, Ghulam; Nader, Ronnie; Koudelka, Otto

2011-09-01

Students in higher education, and scientific and technological researchers want to communicate with the International Space Station (ISS), download live satellite images, and receive telemetry, housekeeping and science/engineering data from nano-satellites and larger spacecrafts. To meet this need the Ecuadorian Civilian Space Agency (EXA) has recently provided the civilian world with an internet-to-orbit gateway (Hermes-A/Minotaur) Space Flight Control Center (SFCC) available for public use. The gateway has a maximum range of tracking and detection of 22,000 km and sensitivity such that it can receive and discriminate the signals from a satellite transmitter with power˜0.1 W. The capability is enough to receive the faintest low-earth-orbit (LEO) satellites. This gateway virtually connects participating internet clients around the world to a remote satellite ground station (GS), providing a broad community for multinational cooperation. The goal of the GS is to lower financial and engineering barriers that hinder access to science and engineering data from orbit. The basic design of the virtual GS on a user side is based on free software suites. Using these and other software tools the GS is able to provide access to orbit for a multitude of users without each having to go through the costly setups. We present the design and implementation of the virtual GS in a higher education and scientific outreach settings. We also discuss the basic architecture of the single existing system and the benefits of a proposed distributed system. Details of the software tools and their applicability to synchronous round-the-world tracking, monitoring and processing performed by students and teams at Graz University of Technology, Austria, EXA-Ecuador, University of Michigan, USA and JAXA who have participated in various mission operations and have investigated real-time satellite data download and image acquisition and processing. Students and other remote users at these institutions undergo training with in orbit satellites in preparation for their own use with future university-class nano-satellites' post launch space operations. The exclusive ability of Hermes-A/Minotaur to act as a gateway between remote users (internet) and satellites (in orbit) makes the virtual GS at user-end more feasible for the long-term real-time nano/cubesats space operations. The only requirement is to have a mutual agreement between EXA and participating university/research organization and broadband internet connection at user-end. With successful and remote satellite tracking and downloading of real-time data from many operational satellites, the Hermes has been found a reliable potential GS for current and future university missions and a training platform for individuals pursuing space operations.

Broadband athermal waveguides and devices for datacom and telecom applications

NASA Astrophysics Data System (ADS)

He, Liuqing; Guo, Yuhao; Han, Zhaohong; Wada, Kazumi; Kimerling, Lionel C.; Michel, Jurgen; Agarwal, Anuradha M.; Li, Guifang; Zhang, Lin

2018-02-01

The high temperature sensitivity of silicon material limits the applications of silicon-based micro-ring resonators in integrated photonics. To realize a low but broadband temperature-dependence-wavelength-shift (TDWS) micro-ring resonator, designing a broadband athermal waveguide becomes a significant task. In this work, we propose a broadband athermal waveguide which shows a low effective thermos-optical coefficient (TOC) of +/-1×10-6/K at 1400 nm to 1700 nm. The proposed waveguide shows low-loss performance of 0.01 dB/cm and stable broadband-athermal ability when it's applied in micro-ring resonators, and the optical loss of micro-ring resonator with a radius of 100 μm using this waveguide is 0.02 dB/cm.

Direct and quantitative broadband absorptance spectroscopy with multilayer cantilever probes

DOEpatents

Hsu, Wei-Chun; Tong, Jonathan Kien-Kwok; Liao, Bolin; Chen, Gang

2015-04-21

A system for measuring the absorption spectrum of a sample is provided that includes a broadband light source that produces broadband light defined within a range of an absorptance spectrum. An interferometer modulates the intensity of the broadband light source for a range of modulation frequencies. A bi-layer cantilever probe arm is thermally connected to a sample arm having at most two layers of materials. The broadband light modulated by the interferometer is directed towards the sample and absorbed by the sample and converted into heat, which causes a temperature rise and bending of the bi-layer cantilever probe arm. A detector mechanism measures and records the deflection of the probe arm so as to obtain the absorptance spectrum of the sample.

7 CFR 1738.11 - Availability of broadband service.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Availability of broadband service. 1738.11 Section 1738.11 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE RURAL BROADBAND ACCESS LOANS AND LOAN GUARANTEES Loan Purposes and Basic Policies...

Funding Public Computing Centers: Balancing Broadband Availability and Expected Demand

ERIC Educational Resources Information Center

Jayakar, Krishna; Park, Eun-A

2012-01-01

The National Broadband Plan (NBP) recently announced by the Federal Communication Commission visualizes a significantly enhanced commitment to public computing centers (PCCs) as an element of the Commission's plans for promoting broadband availability. In parallel, the National Telecommunications and Information Administration (NTIA) has…

Fan Noise Source Diagnostic Test Computation of Rotor Wake Turbulence Noise

NASA Technical Reports Server (NTRS)

Nallasamy, M.; Envia, E.; Thorp, S. A.; Shabbir, A.

2002-01-01

An important source mechanism of fan broadband noise is the interaction of rotor wake turbulence with the fan outlet guide vanes. A broadband noise model that utilizes computed rotor flow turbulence from a RANS code is used to predict fan broadband noise spectra. The noise model is employed to examine the broadband noise characteristics of the 22-inch Source Diagnostic Test fan rig for which broadband noise data were obtained in wind tunnel tests at the NASA Glenn Research Center. A 9-case matrix of three outlet guide vane configurations at three representative fan tip speeds are considered. For all cases inlet and exhaust acoustic power spectra are computed and compared with the measured spectra where possible. In general, the acoustic power levels and shape of the predicted spectra are in good agreement with the measured data. The predicted spectra show the experimentally observed trends with fan tip speed, vane count, and vane sweep. The results also demonstrate the validity of using CFD-based turbulence information for fan broadband noise calculations.

Estimation of Mesospheric Densities at Low Latitudes Using the Kunming Meteor Radar Together With SABER Temperatures

NASA Astrophysics Data System (ADS)

Yi, Wen; Xue, Xianghui; Reid, Iain M.; Younger, Joel P.; Chen, Jinsong; Chen, Tingdi; Li, Na

2018-04-01

Neutral mesospheric densities at a low latitude have been derived during April 2011 to December 2014 using data from the Kunming meteor radar in China (25.6°N, 103.8°E). The daily mean density at 90 km was estimated using the ambipolar diffusion coefficients from the meteor radar and temperatures from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument. The seasonal variations of the meteor radar-derived density are consistent with the density from the Mass Spectrometer and Incoherent Scatter (MSIS) model, show a dominant annual variation, with a maximum during winter, and a minimum during summer. A simple linear model was used to separate the effects of atmospheric density and the meteor velocity on the meteor radar peak detection height. We find that a 1 km/s difference in the vertical meteor velocity yields a change of approximately 0.42 km in peak height. The strong correlation between the meteor radar density and the velocity-corrected peak height indicates that the meteor radar density estimates accurately reflect changes in neutral atmospheric density and that meteor peak detection heights, when adjusted for meteoroid velocity, can serve as a convenient tool for measuring density variations around the mesopause. A comparison of the ambipolar diffusion coefficient and peak height observed simultaneously by two co-located meteor radars indicates that the relative errors of the daily mean ambipolar diffusion coefficient and peak height should be less than 5% and 6%, respectively, and that the absolute error of the peak height is less than 0.2 km.

The Detection of Diffuse Extended Structure in 3C 273: Implications for Jet Power

NASA Astrophysics Data System (ADS)

Punsly, Brian; Kharb, Preeti

2016-12-01

We present deep Very Large Array imaging of 3C 273 in order to determine the diffuse, large scale radio structure of this famous radio-loud quasar. Diffuse extended structure (radio lobes) is detected for the first time in these observations as a consequence of high dynamic range in the 327.5 and 1365 MHz images. This emission is used to estimate a time averaged jet power, 7.2 × 1043 erg s-1 < \\overline{Q} < 3.7 × 1044 erg s-1. Brightness temperature arguments indicate consistent values of the time variability Doppler factor and the compactness Doppler factor for the inner jet, δ ≳ 10. Thus, the large apparent broadband bolometric luminosity of the jet, ˜3 × 1046 erg s-1, corresponds to a modest intrinsic luminosity ≳1042 erg s-1, or ˜1% of \\overline{Q}. In summary, we find that 3C 273 is actually a “typical” radio-loud quasar contrary to suggestions in the literature. The modest \\overline{Q} is near the peak of the luminosity distribution for radio-loud quasars and it is consistent with the current rate of dissipation emitted from millimeter wavelengths to gamma rays. The extreme core-jet morphology is an illusion from a near pole-on line of sight to a highly relativistic jet that produces a Doppler enhanced glow that previously swamped the lobe emission. 3C 273 apparently has the intrinsic kpc scale morphology of a classical double radio source, but it is distorted by an extreme Doppler aberration.

Enhanced performance of solution-processed broadband photodiodes by epitaxially blending MAPbBr3 quantum dots and ternary PbSxSe1-x quantum dots as the active layer.

PubMed

Sulaman, Muhammad; Yang, Shengyi; Jiang, Yurong; Tang, Yi; Zou, Bingsuo

2017-12-15

Organic-inorganic hybrid photodetectors attract more and more interest, since they can combine the advantages of both organic and inorganic materials into one device, and broadband photodetectors are widely used in many scientific and industrial fields. In this work, we demonstrate the enhanced-performance solution-processed broadband photodiodes by epitaxially blending organo-lead halide perovskite (MAPbBr 3 ) colloidal quantum dots (CQDs) with ternary PbS x Se 1-x CQDs as the active layer. As a result, the interfacial features of the hetero-epitaxial nanocomposite MAPbBr 3 :PbS x Se 1-x enables the design and perception of functionalities that are not available for the single-phase constituents or layered devices. By combining the high electrical transport properties of MAPbBr 3 QDs with the highly radiative efficiency of PbS 0.4 Se 0.6 QDs, the photodiodes ITO/ZnO/PbS 0.4 Se 0.6 :MAPbBr 3 /Au exhibit a maximum photoresponsivity and specific detectivity of 21.48 A W -1 and 3.59 × 10 13 Jones, 22.16 A W -1 and 3.70 × 10 13 Jones at room temperature under 49.8 μW cm -2 532 nm laser and 62 μW cm -2 980 nm laser, respectively. This is higher than that of the layered photodiodes ITO/ZnO/PbS 0.4 Se 0.6 /MAPbBr 3 /Au, pure perovskite (MAPbBr 3 ) (or PbS 0.4 Se 0.6 ) QD-based photodiodes reported previously, and it is also better than the traditional inorganic semiconductor-based photodetectors. Our experimental results indicate that epitaxially-aligned nanocomposites (MAPbBr 3 :PbS x Se 1-x ) exhibit remarkable optoelectronic properties that are traceable to their atomic-scale crystalline coherence, and one can utilize the excellent photocarrier diffusion from PbS x Se 1-x into the perovskite to enhance the device performance from the UV-visible to infrared region.

Enhanced performance of solution-processed broadband photodiodes by epitaxially blending MAPbBr3 quantum dots and ternary PbSxSe1-x quantum dots as the active layer

NASA Astrophysics Data System (ADS)

Sulaman, Muhammad; Yang, Shengyi; Jiang, Yurong; Tang, Yi; Zou, Bingsuo

2017-12-01

Organic-inorganic hybrid photodetectors attract more and more interest, since they can combine the advantages of both organic and inorganic materials into one device, and broadband photodetectors are widely used in many scientific and industrial fields. In this work, we demonstrate the enhanced-performance solution-processed broadband photodiodes by epitaxially blending organo-lead halide perovskite (MAPbBr3) colloidal quantum dots (CQDs) with ternary PbSxSe1-x CQDs as the active layer. As a result, the interfacial features of the hetero-epitaxial nanocomposite MAPbBr3:PbSxSe1-x enables the design and perception of functionalities that are not available for the single-phase constituents or layered devices. By combining the high electrical transport properties of MAPbBr3 QDs with the highly radiative efficiency of PbS0.4Se0.6 QDs, the photodiodes ITO/ZnO/PbS0.4Se0.6:MAPbBr3/Au exhibit a maximum photoresponsivity and specific detectivity of 21.48 A W-1 and 3.59 × 1013 Jones, 22.16 A W-1 and 3.70 × 1013 Jones at room temperature under 49.8 μW cm-2 532 nm laser and 62 μW cm-2 980 nm laser, respectively. This is higher than that of the layered photodiodes ITO/ZnO/PbS0.4Se0.6/MAPbBr3/Au, pure perovskite (MAPbBr3) (or PbS0.4Se0.6) QD-based photodiodes reported previously, and it is also better than the traditional inorganic semiconductor-based photodetectors. Our experimental results indicate that epitaxially-aligned nanocomposites (MAPbBr3:PbSxSe1-x) exhibit remarkable optoelectronic properties that are traceable to their atomic-scale crystalline coherence, and one can utilize the excellent photocarrier diffusion from PbSxSe1-x into the perovskite to enhance the device performance from the UV-visible to infrared region.

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