The Advanced Communication Technology Satellite and ISDN

NASA Technical Reports Server (NTRS)

Lowry, Peter A.

1996-01-01

This paper depicts the Advanced Communication Technology Satellite (ACTS) system as a global central office switch. The ground portion of the system is the collection of earth stations or T1-VSAT's (T1 very small aperture terminals). The control software for the T1-VSAT's resides in a single CPU. The software consists of two modules, the modem manager and the call manager. The modem manager (MM) controls the RF modem portion of the T1-VSAT. It processes the orderwires from the satellite or from signaling generated by the call manager (CM). The CM controls the Recom Laboratories MSPs by receiving signaling messages from the stacked MSP shelves ro units and sending appropriate setup commands to them. There are two methods used to setup and process calls in the CM; first by dialing up a circuit using a standard telephone handset or, secondly by using an external processor connected to the CPU's second COM port, by sending and receiving signaling orderwires. It is the use of the external processor which permits the ISDN (Integrated Services Digital Network) Signaling Processor to implement ISDN calls. In August 1993, the initial testing of the ISDN Signaling Processor was carried out at ACTS System Test at Lockheed Marietta, Princeton, NJ using the spacecraft in its test configuration on the ground.

Electronics design of a multi-rate DPSK modem for free-space optical communications

NASA Astrophysics Data System (ADS)

Rao, H. G.; Browne, C. A.; Caplan, D. O.; Carney, J. J.; Chavez, M. L.; Fletcher, A. S.; Fitzgerald, J. J.; Kaminsky, R. D.; Lund, G.; Hamilton, S. A.; Magliocco, R. J.; Mikulina, O. V.; Murphy, R. J.; Seaver, M. M.; Scheinbart, M. S.; Spellmeyer, N. W.; Wang, J. P.

2014-03-01

We have designed and experimentally demonstrated a radiation-hardened modem suitable for NASA's Laser Communications Relay Demonstration. The modem supports free-space DPSK communication over a wide range of channel rates, from 72 Mb/s up to 2.88 Gb/s. The modem transmitter electronics generate a bursty DPSK waveform, such that only one optical modulator is required. The receiver clock recovery is capable of operating over all channel rates at average optical signal levels below -70 dBm. The modem incorporates a radiation-hardened Xilinx Virtex 5 FPGA and a radiation-hardened Aeroflex UT699 CPU. The design leverages unique capabilities of each device, such as the FPGA's multi-gigabit transceivers. The modem scrubs itself against radiation events, but does not require pervasive triple-mode redundant logic. The modem electronics include automatic stabilization functions for its optical components, and software to control its initialization and operation. The design allows the modem to be put into a low-power standby mode.

Open Source Service Agent (OSSA) in the intelligence community's Open Source Architecture

NASA Technical Reports Server (NTRS)

Fiene, Bruce F.

1994-01-01

The Community Open Source Program Office (COSPO) has developed an architecture for the intelligence community's new Open Source Information System (OSIS). The architecture is a multi-phased program featuring connectivity, interoperability, and functionality. OSIS is based on a distributed architecture concept. The system is designed to function as a virtual entity. OSIS will be a restricted (non-public), user configured network employing Internet communications. Privacy and authentication will be provided through firewall protection. Connection to OSIS can be made through any server on the Internet or through dial-up modems provided the appropriate firewall authentication system is installed on the client.

47 CFR 90.475 - Operation of internal transmitter control systems in specially equipped systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... telephone network (PSTN), nor uses dial-up circuits in the PSTN. Licensees with complex communications... access these base stations through the microwave or operational fixed systems from positions in the PSTN... circuit is provided for each mode of transmitter operation (i.e., conventional, dial-up or Internet). (3...

47 CFR 90.475 - Operation of internal transmitter control systems in specially equipped systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... telephone network (PSTN), nor uses dial-up circuits in the PSTN. Licensees with complex communications... access these base stations through the microwave or operational fixed systems from positions in the PSTN... circuit is provided for each mode of transmitter operation (i.e., conventional, dial-up or Internet). (3...

47 CFR 90.475 - Operation of internal transmitter control systems in specially equipped systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... telephone network (PSTN), nor uses dial-up circuits in the PSTN. Licensees with complex communications... access these base stations through the microwave or operational fixed systems from positions in the PSTN... circuit is provided for each mode of transmitter operation (i.e., conventional, dial-up or Internet). (3...

47 CFR 90.475 - Operation of internal transmitter control systems in specially equipped systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... telephone network (PSTN), nor uses dial-up circuits in the PSTN. Licensees with complex communications... access these base stations through the microwave or operational fixed systems from positions in the PSTN... circuit is provided for each mode of transmitter operation (i.e., conventional, dial-up or Internet). (3...

Bandwidth Efficient Wireless Digital Modem Developed

NASA Technical Reports Server (NTRS)

Kifle, Muli

1999-01-01

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

First Applications of DoD Iridium RUDICS in the NSF Polar Programs

NASA Astrophysics Data System (ADS)

Valentic, T.; Stehle, R.

2008-12-01

We will present the first deployment and application of the new Iridium RUDICS service to remote instrumentation projects within the National Science Foundation's polar programs. The rise of automated observing networks has increased the demand for real-time connectivity to remote instruments, not only for immediate access to data, but to also interrogate health and status. Communicating with field sites in the polar regions is complicated by the remoteness from existing infrastructure, low temperatures and limited connection options. Sites located above 78° latitude are not able to see geostationary satellites, leaving the Iridium constellation as the only one that provide a direct connection. Some others, such as Orbcomm, only provide a store-and-forward service. Iridium is often used as a dial up modem to establish a PPP connection to the Internet with data files transferred via FTP. On low-bandwidth, high-latency networks like Iridium (2400bps with ping times of seconds), this approach is time consuming and inefficient. The dial up time alone takes upwards of a minute, and standard TCP/IP and FTP protocols are hampered by the long latencies. Minimizing transmission time is important for reducing battery usage and connection costs. The new Iridium RUDICS service can be used for more efficient transfers. RUDICS is an acronym for "Router-based Unstructured Digital Inter-working Connectivity Solution" and provides a direct connection between an instrument in the field and a server on the Internet. After dialing into the Iridium gateway, a socket connection is opened to a registered port on a user's server. Bytes sent to or from the modem appear at the server's socket. The connection time is reduced to about 10 seconds because the modem training and PPP negotiation stages are eliminated. The remote device does not need to have a full TCP/IP stack, allowing smaller instruments such as data loggers to directly handle the data transmission. Alternative protocols can be deployed that better exploit the characteristics of the Iridium channel. In addition, the setup naturally scales to handle hundreds of remote devices, an important aspect for larger sensor networks. As part of the NSF's Arctic Research Support and Logistics Services, we have deployed RUDICS systems with three different research projects. These are the first NSF RUDICS deployments for projects using the Department of Defense Iridium gateway, which allows for unlimited connection time at a flat monthly rate for US government users. The first project is O-Buoy, an IPY-OASIS project for self-contained, autonomous observations of atmospheric chemical species in the polar marine boundary layer. The second project is collection of low-power instrument towers on Alaska's North Slope at Imnavait Creek, part of the Arctic Observation Network (AON). Lastly, the autonomous instrument platform at Ivotuk, Alaska, uses RUDICS to provide telemetry about the renewable energy systems. A set of real-time web displays allow researchers for each project to monitor their remote sites and access real-time data.

The design, marketing, and implementation of online continuing education about computers and nursing informatics.

PubMed

Sweeney, Nancy M; Saarmann, Lembi; Seidman, Robert; Flagg, Joan

2006-01-01

Asynchronous online tutorials using PowerPoint slides with accompanying audio to teach practicing nurses about computers and nursing informatics were designed for this project, which awarded free continuing education units to completers. Participants had control over the advancement of slides, with the ability to repeat when desired. Graphics were kept to a minimum; thus, the program ran smoothly on computers using dial-up modems. The tutorials were marketed in live meetings and through e-mail messages on nursing listservs. Findings include that the enrollment process must be automated and instantaneous, the program must work from every type of computer and Internet connection, marketing should be live and electronic, and workshops should be offered to familiarize nurses with the online learning system.

46 CFR 525.3 - Availability of marine terminal operator schedules.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Availability of terminal schedules—(1) Availability to the Commission. A complete and current set of terminal... computer (PC) by: (1) Dial-up connection via public switched telephone networks (PSTN); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (c) Dial-up connection via PSTN. (1) This connection...

46 CFR 525.3 - Availability of marine terminal operator schedules.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Availability of terminal schedules—(1) Availability to the Commission. A complete and current set of terminal... computer (PC) by: (1) Dial-up connection via public switched telephone networks (PSTN); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (c) Dial-up connection via PSTN. (1) This connection...

Dial-in flow cytometry data analysis.

PubMed

Battye, Francis L

2002-02-01

As listmode data files continue to grow larger, access via any kind of network connections becomes more and more trouble because of the enormous traffic generated. The limited speed of transmission via modem makes analysis almost impossible. This unit presents a solution to these problems, one that involves installation at the central storage facility of a small computer program called a Web servlet. Operating in concert with a Web server, the servlet assists the analysis by extracting the display array from the data file and organizing its transmission over the network to a remote client program that creates the data display. The author discusses a recent implementation of this solution and the results for model transmission of two typical data files. The system greatly speeds access to remotely stored data yet retains the flexibility of manipulation expected with local access.

Use of computer systems and process information for blast furnace operations at U. S. Steel, Gary Works

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

Sherman, G.J.; Zmierski, M.L.

1994-09-01

US Steel Iron Producing Div. consists of four operating blast furnaces ranging in process control capabilities from 1950's and 1960's era hardware to state of the art technology. The oldest control system consists of a large number of panels containing numerous relays, indicating lights, selector switches, push buttons, analog controllers, strip chart recorders and annunciators. In contrast, the state of the art control system utilizes remote I/O, two sets of redundant PLC's, redundant charge director computer, redundant distributed control system, high resolution video-graphic display system and supervisory computer for real-time data acquisition. Process data are collected and archived on twomore » DEC VAX computers, one for No. 13 blast furnace and the other for the three south end furnaces. Historical trending, data analysis and reporting are available to iron producing personnel through terminals and PC's connected directly to the systems, dial-up modems and various network configurations. These two machines are part of the iron producing network which allows them to pass and receive information from each other as well as numerous other sources throughout the division. This configuration allows personnel to access most pertinent furnace information from a single source. The basic objective of the control systems is to charge raw materials to the top of the furnace at aim weights and sequence, while maintaining blast conditions at the bottom of the furnace at required temperature, pressure and composition. Control changes by the operators are primarily supervisory based on review of system generated plots and tables.« less

Cable Modems' Transmitted RF: A Study of SNR, Error Rates, Transmit Levels, and Trouble Call Metrics

ERIC Educational Resources Information Center

Tebbetts, Jo A.

2013-01-01

Hypotheses were developed and tested to measure the cable modems operational metrics response to a reconfiguration of the cable modems' transmitted RF applied to the CMTS. The purpose of this experiment was to compare two groups on the use of non-federal RF spectrum to determine if configuring the cable modems' transmitted RF from 25.2…

Boundary Layer Observations of Water Vapor and Aerosol Profiles with an Eye-Safe Micro-Pulse Differential Absorption Lidar (DIAL)

NASA Astrophysics Data System (ADS)

Nehrir, A. R.; Repasky, K. S.; Carlsten, J.; Ismail, S.

2011-12-01

Measurements of real-time high spatial and temporal resolution profiles of combined water vapor and aerosols in the boundary layer have been a long standing observational challenge to the meteorological, weather forecasting, and climate science communities. To overcome the high reoccurring costs associated with radiosondes as well as the lack of sufficient water vapor measurements over the continental united states, a compact and low cost eye-safe all semiconductor-based micro-pulse differential absorption lidar (DIAL) has been developed for water vapor and aerosol profiling in the lower troposphere. The laser transmitter utilizes two continuous wave external cavity diode lasers operating in the 830 nm absorption band as the online and offline seed laser sources. An optical switch is used to sequentially injection seed a tapered semiconductor optical amplifier (TSOA) with the two seed laser sources in a master oscillator power amplifier (MOPA) configuration. The TSOA is actively current pulsed to produce up to 7 μJ of output energy over a 1 μs pulse duration (150 m vertical resolution) at a 10 kHz pulse repetition frequency. The measured laser transmitter spectral linewidth is less than 500 kHz while the long term frequency stability of the stabilized on-line wavelength is ± 55 MHz. The laser transmitter spectral purity was measured to be greater than 0.9996, allowing for simultaneous measurements of water vapor in the lower and upper troposphere. The DIAL receiver utilizes a commercially available full sky-scanning capable 35 cm Schmidt-Cassegrain telescope to collect the scattered light from the laser transmitter. Light collected by the telescope is spectrally filtered to suppress background noise and is coupled into a fiber optic cable which acts as the system field stop and limits the full angle field of view to 140 μrad. The light is sampled by a fiber coupled APD operated in a Geiger mode. The DIAL instrument is operated autonomously where water vapor and aerosol profiles are displayed in real-time. The transmitter is capable of operating at any spectral position along the selected water vapor absorption line allowing for year round operation at various geographical locations using a single line. Water vapor and aerosol profiles have been recorded up to 6 km and 15 km with 10 m and 1 m temporal averaging, respectively, allowing for mesoscale monitoring of boundary layer dynamics during both daytime and nighttime operation. A brief description of the current status of the water vapor DIAL instrument will be presented. Nighttime and daytime water vapor and aerosol profiles/inversions from the DIAL instrument will also be presented and favorable comparisons against collocated radiosonde, in situ, and column averaged data from SUOMINET and AERONET will also be discussed. A future outlook towards instrument enhancements that will allow the diode-laser-based DIAL technique/technology to become a viable candidate for deployment in multi-point sensor networks will also be discussed.

Air Traffic Control Experimentation and Evaluation with the NASA ATS-6 Satellite : Volume 6. Modem Evaluation Test

DOT National Transportation Integrated Search

1976-09-01

Results of performance evaluation of voice, digital data and ranging modems in the aeronautical satellite environment are given. Approximately 80 hours of modem performance data were acquired on board an FAA KC-135 jet aircraft operating over the Nor...

Defense Healthcare Information Assurance Program

DTIC Science & Technology

1999-11-01

56k Modem • Cisco 1OS 12.0 operation at the MTFs, the Team • Cisco 3640 Router Configuration Fileo 24- 56k Modems recommended the Cisco 3600 series...temporarily substituted by the vendor pending availability of ordered components (e.g., the modem circuit board for the router). " Each site created a...control for software / hardware modifications and upgrades? 3.5 Is there a process for introducing new equipment (such as hosts, printers, or modems

Theory and operation of the real-time data acquisition system for the NASA-LaRC differential absorption lidar (DIAL)

NASA Technical Reports Server (NTRS)

Butler, C.

1986-01-01

The improvement of computer hardware and software of the NASA Multipurpose Differential Absorption Lidar (DIAL) system is documented. The NASA DIAL system is undergoing development and experimental deployment at NASA Langley Research Center for the remote measurement of atmospheric trace gas concentrations from ground and aircraft platforms. A viable DIAL system was developed capable of remotely measuring O3 and H2O concentrations from an aircraft platform. Test flights of the DIAL system were successfully performed onboard the NASA Goddard Flight Center Electra aircraft from 1980 to 1985. The DIAL Data Acquisition System has undergone a number of improvements over the past few years. These improvements have now been field tested. The theory behind a real time computer system as it applies to the needs of the DIAL system is discussed. This report is designed to be used as an operational manual for the DIAL DAS.

Theory and operation of the real-time data acquisition system for the NASA-LaRC differential absorption lidar (DIAL)

NASA Technical Reports Server (NTRS)

Butler, Carolyn; Spencer, Randall

1988-01-01

The improvement of computer hardware and software of the NASA Multipurpose Differential Absorption Lidar (DIAL) system is documented. The NASA DIAL system has undergone development and experimental deployment at NASA/Langley Res. Center for the remote measurement of atmospheric trace gas concentrations from ground and aircraft platforms. A viable DIAL system was developed capable of remotely measuring O3 and H2O concentrations from an aircraft platform. The DIAL Data Acquisition System (DAS) has undergone a number of improvements also. Due to the participation of the DIAL in the Global Tropospheric Experiment, modifications and improvements of the system were tested and used both in the lab and in air. Therefore, this is an operational manual for the DIAL DAS.

Digital 8-DPSK Modem For Trellis-Coded Communication

NASA Technical Reports Server (NTRS)

Jedrey, T. C.; Lay, N. E.; Rafferty, W.

1989-01-01

Digital real-time modem processes octuple differential-phase-shift-keyed trellis-coded modulation. Intended for use in communicating data at rate up to 4.8 kb/s in land-mobile satellite channel (Rician fading) of 5-kHz bandwidth at carrier frequency of 1 to 2 GHz. Modulator and demodulator contain digital signal processors performing modem functions. Design flexible in that functions altered via software. Modem successfully tested and evaluated in both laboratory and field experiments, including recent full-scale satellite experiment. In all cases, modem performed within 1 dB of theory. Other communication systems benefitting from this type of modem include land mobile (without satellites), paging, digitized voice, and frequency-modulation subcarrier data broadcasting.

Examination of the Lateral Attenuation of Aircraft Noise

NASA Technical Reports Server (NTRS)

Plotkin, Kenneth J.; Hobbs, Christopher M.; Bradley, Kevin A.; Shepherd, Kevin P. (Technical Monitor)

2000-01-01

Measurements of the lateral attenuation of noise from aircraft operations at Denver International Airport were made at distances up to 2000 feet and elevation angles up to 27 degrees. Attenuation Calculated from modem ground impedance theory agrees well with average measured attenuation. The large variability between measured and predicted levels observed at small elevation angles is demonstrated to be due to refraction by wind and temperature gradients.

Differential Absorption Lidar (DIAL) in Alberta: A New Remote Sensing Tool for Wide Area Measurement of Particulates, CO2, and CH4 Emissions from Energy Extraction and Production Sites

NASA Astrophysics Data System (ADS)

Wojcik, M.; Lemon, R.; Crowther, B. G.; Valupadas, P.; Fu, L.; Yang, Z.; Huda, Q.; Leung, B.; Chambers, A.

2014-12-01

Alberta Environmental Monitoring, Evaluation and Reporting Agency (AEMERA) in cooperation with the Space Dynamics Laboratory (SDL) of Utah State University, have developed a mobile DIAL sensor designed specifically for particle, CO2 and CH4 emissions measurement. Rapid expansion of the oil and gas industry in Alberta, including the oil sands, has challenged the Alberta Government to keep pace in its efforts to monitor and mitigate the environmental impacts of development. The limitations of current monitoring systems has pushed the provincial government to seek out advanced sensing technologies such as differential absorption lidar (DIAL) to help assess the impact of energy development and industrial operations. This instrument is housed inside a 36' trailer and can be quickly staged and used to characterize source emissions and to locate fugitive leaks. DIAL is capable of measuring concentrations for carbon dioxide (CO2) and methane (CH4) at ranges of up to 3 km with a spatial resolution of 1.5 m. DIAL can map both CO2 and CH4, as well as particulate matter (PM) in a linear fashion; by scanning the laser beam in both azimuth and elevation, DIAL can create images of emissions concentrations and ultimately can be used to determine emission factors, locate fugitive leaks, assess plume dispersion and confirm air dispersion modeling. The DIAL system has been deployed at a landfill, a coal-fired power plant, and an oil sands production area. A system overview of the DIAL instrument and recent results will be discussed.

Timing and frequency considerations in the worldwide testing of a spread spectrum communication system

NASA Technical Reports Server (NTRS)

Woodring, D. G.; Nichols, S. A.; Swanson, R.

1979-01-01

During 1978 and 1979, an Air Force C-135 test aircraft was flown to various locations in the North and South Atlantic and Pacific Oceans for satellite communications experiments. A part of the equipment tested on the aircraft was the SEACOM spread spectrum modem. The SEACOM modem operated at X band frequency from the aircraft via the DSCS II satellite to a ground station. For data to be phased successfully, it was necessary to maintain independent time and frequency accuracy over relatively long periods of time (up to two weeks) on the aircraft and at the ground station. To achieve this goal, two Efratom atomic frequency standards were used. The performance of these frequency standards as used in the spread spectrum modem is discussed, including the effects of high relative velocity, synchronization and the effects of the frequency standards on data performance is discussed. The aircraft environment, which includes extremes of temperature, as well as long periods of shutdown followed by rapid warmup requirements, is also discussed.

Modems for emerging digital cellular-mobile radio system

NASA Technical Reports Server (NTRS)

Feher, Kamilo

1991-01-01

Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.

Performance of a Q-M/PSK Data Modem Operating in a Voice and Data Mode Through the ATS-6 Satellite

DOT National Transportation Integrated Search

1979-02-01

Experiments were conducted in cooperation with the Communications Research Center (CRC) of Canada to gather additional performance data on the error statistics of the digital data channel of the Q-M/PSK Voice and Data Modem, while operating in the hy...

FEC combined burst-modem for business satellite communications use

NASA Astrophysics Data System (ADS)

Murakami, K.; Miyake, M.; Fuji, T.; Moritani, Y.; Fujino, T.

The authors recently developed two types of FEC (forward error correction) combined modems both applicable to low-data-rate and intermediate-data-rate TDMA international satellite communications. Each FEC combined modem consists of a QPSK (quadrature phase-shift keyed) modem, a convolutional encoder, and a Viterbi decoder. Both modems are designed taking into consideration the fast acquisition of the carrier and bit timing and the low cycle slipping rate in the low-carrier-to-noise-ratio environment. Attention is paid to designing the Viterbi decoder to be operated in a situation in which successive bursts may have different coding rates according to the punctured coding scheme. The overall scheme of the FEC combined modems are presented, and some of the key technologies applied in developing them are outlined. The hardware implementation and experimentation are also discussed. The measured data are compared with results of theoretical analysis, and relatively good performances are obtained.

Mobile phone radiation induces mode-dependent DNA damage in a mouse spermatocyte-derived cell line: a protective role of melatonin.

PubMed

Liu, Chuan; Gao, Peng; Xu, Shang-Cheng; Wang, Yuan; Chen, Chun-Hai; He, Min-Di; Yu, Zheng-Ping; Zhang, Lei; Zhou, Zhou

2013-11-01

To evaluate whether exposure to mobile phone radiation (MPR) can induce DNA damage in male germ cells. A mouse spermatocyte-derived GC-2 cell line was exposed to a commercial mobile phone handset once every 20 min in standby, listen, dialed or dialing modes for 24 h. DNA damage was determined using an alkaline comet assay. The levels of DNA damage were significantly increased following exposure to MPR in the listen, dialed and dialing modes. Moreover, there were significantly higher increases in the dialed and dialing modes than in the listen mode. Interestingly, these results were consistent with the radiation intensities of these modes. However, the DNA damage effects of MPR in the dialing mode were efficiently attenuated by melatonin pretreatment. These results regarding mode-dependent DNA damage have important implications for the safety of inappropriate mobile phone use by males of reproductive age and also suggest a simple preventive measure: Keeping mobile phones as far away from our body as possible, not only during conversations but during 'dialed' and 'dialing' operation modes. Since the 'dialed' mode is actually part of the standby mode, mobile phones should be kept at a safe distance from our body even during standby operation. Furthermore, the protective role of melatonin suggests that it may be a promising pharmacological candidate for preventing mobile phone use-related reproductive impairments.

Web servlet-assisted, dial-in flow cytometry data analysis.

PubMed

Battye, F

2001-02-01

The obvious benefits of centralized data storage notwithstanding, the size of modern flow cytometry data files discourages their transmission over commonly used telephone modem connections. The proposed solution is to install at the central location a web servlet that can extract compact data arrays, of a form dependent on the requested display type, from the stored files and transmit them to a remote client computer program for display. A client program and a web servlet, both written in the Java programming language, were designed to communicate over standard network connections. The client program creates familiar numerical and graphical display types and allows the creation of gates from combinations of user-defined regions. Data compression techniques further reduce transmission times for data arrays that are already much smaller than the data file itself. For typical data files, network transmission times were reduced more than 700-fold for extraction of one-dimensional (1-D) histograms, between 18 and 120-fold for 2-D histograms, and 6-fold for color-coded dot plots. Numerous display formats are possible without further access to the data file. This scheme enables telephone modem access to centrally stored data without restricting flexibility of display format or preventing comparisons with locally stored files. Copyright 2001 Wiley-Liss, Inc.

Nads FSK Modem, LEA 74-2248

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

Johnson, K.R.

1976-01-12

The Nads FSK Modem is a compact unit designed to operate in conjunction with EIA standard interfacing and the data terminal equipment of the 1200 Baud digital communications network of the Nevada Automated Diagnostics System (NADS). The modem is constructed in a Nuclear Instrumentation Module System (NIMS) module for compatability with the NADS system. The modulator section of the modem accepts serial, digital signals at 1200 Baud which may be either standard TTL levels or bipolar signals meeting either the EIA RS-232C or RS-232B standards. The output of the modulator is a Frequency-Shift Keyed (FSK) signal having frequencies of 2.2more » kHz for Mark and 1.2 kHz for Space. The demodulator section accepts the above FSK signal as input, and outputs serial, digital signals at 1200 Baud at either TTL or EIA RS-232C levels. Specifications and operation and calibration instructions are given. (WHK)« less

A multi-rate DPSK modem for free-space laser communications

NASA Astrophysics Data System (ADS)

Spellmeyer, N. W.; Browne, C. A.; Caplan, D. O.; Carney, J. J.; Chavez, M. L.; Fletcher, A. S.; Fitzgerald, J. J.; Kaminsky, R. D.; Lund, G.; Hamilton, S. A.; Magliocco, R. J.; Mikulina, O. V.; Murphy, R. J.; Rao, H. G.; Scheinbart, M. S.; Seaver, M. M.; Wang, J. P.

2014-03-01

The multi-rate DPSK format, which enables efficient free-space laser communications over a wide range of data rates, is finding applications in NASA's Laser Communications Relay Demonstration. We discuss the design and testing of an efficient and robust multi-rate DPSK modem, including aspects of the electrical, mechanical, thermal, and optical design. The modem includes an optically preamplified receiver, an 0.5-W average power transmitter, a LEON3 rad-hard microcontroller that provides the command and telemetry interface and supervisory control, and a Xilinx Virtex-5 radhard reprogrammable FPGA that both supports the high-speed data flow to and from the modem and controls the modem's analog and digital subsystems. For additional flexibility, the transmitter and receiver can be configured to support operation with multi-rate PPM waveforms.

Performance evaluation of a 1.6-µm methane DIAL system from ground, aircraft and UAV platforms.

PubMed

Refaat, Tamer F; Ismail, Syed; Nehrir, Amin R; Hair, John W; Crawford, James H; Leifer, Ira; Shuman, Timothy

2013-12-16

Methane is an efficient absorber of infrared radiation and a potent greenhouse gas with a warming potential 72 times greater than carbon dioxide on a per molecule basis. Development of methane active remote sensing capability using the differential absorption lidar (DIAL) technique enables scientific assessments of the gas emission and impacts on the climate. A performance evaluation of a pulsed DIAL system for monitoring atmospheric methane is presented. This system leverages a robust injection-seeded pulsed Nd:YAG pumped Optical Parametric Oscillator (OPO) laser technology operating in the 1.645 µm spectral band. The system also leverages an efficient low noise, commercially available, InGaAs avalanche photo-detector (APD). Lidar signals and error budget are analyzed for system operation on ground in the range-resolved DIAL mode and from airborne platforms in the integrated path DIAL (IPDA) mode. Results indicate system capability of measuring methane concentration profiles with <1.0% total error up to 4.5 km range with 5 minute averaging from ground. For airborne IPDA, the total error in the column dry mixing ratio is less than 0.3% with 0.1 sec average using ground returns. This system has a unique capability of combining signals from the atmospheric scattering from layers above the surface with ground return signals, which provides methane column measurement between the atmospheric scattering layer and the ground directly. In such case 0.5% and 1.2% total errors are achieved with 10 sec average from airborne platforms at 8 km and 15.24 km altitudes, respectively. Due to the pulsed nature of the transmitter, the system is relatively insensitive to aerosol and cloud interferences. Such DIAL system would be ideal for investigating high latitude methane releases over polar ice sheets, permafrost regions, wetlands, and over ocean during day and night. This system would have commercial potential for fossil fuel leaks detection and industrial monitoring applications.

DDN (Defense Data Network) Protocol Implementations and Vendors Guide

DTIC Science & Technology

1987-08-01

length. Lower rates can be selected or determined by attached modem types 303, 209, V.35, or 188-114. Units are in pairs, one at each end of the...ECUs communicate with the IMP via direct cable or modems . DOCUMENTATION: Fully documented vendor product; descriptive literature available...terminals, PCs and modems to an Ethernet. The device can support up to 80 lines and 2 parallel printers. Full domain naming is supported as well as

Practical Design Guidelines for Fugitive Gas Detection from Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Tandy, William D., Jr.

Simulation, design, and analysis are combined in this effort to realize a UAV-scale instrument for fugitive gas detection. The contributing material to the industry begins by extending and correlating an integrated Gaussian plume model useful for instrument predictions and trade studies, regardless of the instrument type or molecule of interest. A variety of generally applicable plots are produced from this foundation, including receiver operator curves for leak rate detectability vs. wind speed, beam diameter vs. leak rate detectability, and plots for required scan densities. The atmospheric and instrument parameter trade studies are followed by hardware-specific analyses applicable to differential absorption lidar (DIAL) instruments. A synopsis of the lessons learned from hands-on experiences in the lab further define the design space for DIAL sensors. The dissertation culminates in the detailed design and analysis of two DIAL instrument concepts. The conclusion is that a DIAL instrument capable of reliably detecting a 50 SCFH plume in winds speeds up to 7 mph is on the threshold of being achievable on a quadcopter platform. Of special note is that the effort was funded by a Pipeline and Hazardous Materials Safety Administration grant and performed in collaboration with Ball Aerospace & Technologies.

DDN (Defense Data Network) Protocol Implementations and Vendors Guide,

DTIC Science & Technology

1986-08-01

3000 feet) in length. Lower rates can be selected or determined by attached modem types 303, 209, V.35, or 188-114. Units are in pairs, one at each...each direction. ECUs communicate with the IMP via direct cable or modems . DOCUMENTATION: Fully documented vendor product; descriptive literature...application is the attachment of terminals, PCs and modems to an Ethernet. The device can support up to 80 lines and 2 parallel printers. Full domain naming

An OKQPSK modem incorporating numerically controlled carrier synthesis

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

Oetken, R.E.

1988-04-04

The feasibility of incorporating numerically controlled oscillators (NCO) in communication related applications is evaluated. NCO generation of sinusoids may prove useful in systems requiring precise frequency control, tuning linearity, and orthogonality versus frequency. An OKQPSK modem operating at a data rate of 200 kb/s was fabricated. The modem operates in a back to back hardwired channel and thus does not incorporate carrier or symbol timing recovery. Spectra of the NCO generated sinusoids are presented along with waveforms from the modulation and demodulation process. Generation of sinusoids in the digital domain is a viable alternative to analog oscillators. Implementation of anmore » NCO should be considered when frequency allocation, tuning bandwidth, or frequency hopped transmission requires precise frequency synthesis. 24 figs.« less

46 CFR 525.3 - Availability of marine terminal operator schedules.

Code of Federal Regulations, 2013 CFR

2013-10-01

... that is made available to the public shall be available during normal business hours and in electronic... computer (PC) by: (1) Dial-up connection via public switched telephone networks (PSTN); or (2) The Internet... incoming calls, (ii) Smart terminal capability for VT-100 terminal or terminal emulation access, and (iii...

46 CFR 525.3 - Availability of marine terminal operator schedules.

Code of Federal Regulations, 2012 CFR

2012-10-01

... that is made available to the public shall be available during normal business hours and in electronic... computer (PC) by: (1) Dial-up connection via public switched telephone networks (PSTN); or (2) The Internet... incoming calls, (ii) Smart terminal capability for VT-100 terminal or terminal emulation access, and (iii...

46 CFR 525.3 - Availability of marine terminal operator schedules.

Code of Federal Regulations, 2014 CFR

2014-10-01

... that is made available to the public shall be available during normal business hours and in electronic... computer (PC) by: (1) Dial-up connection via public switched telephone networks (PSTN); or (2) The Internet... incoming calls, (ii) Smart terminal capability for VT-100 terminal or terminal emulation access, and (iii...

Development and Testing of a Scanning Differential Absorption Lidar For Carbon Sequestration Site Monitoring

NASA Astrophysics Data System (ADS)

Soukup, B.; Johnson, W.; Repasky, K. S.; Carlsten, J. L.

2013-12-01

A scanning differential absorption lidar (DIAL) instrument for carbon sequestration site monitoring is under development and testing at Montana State University. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the on-line absorption wavelength at 1571.4067 nm and the second operating at the off-line wavelength at 1571.2585 nm. Two in-line fiber optic switches are used to switch between on-line and off-line operation. After the fiber optic switches, an acousto-optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66 J and a pulse repetition frequency of 15 kHz. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a fiber coupled photo-multiplier tube (PMT) module operating in the photon counting mode. The PMT has a 3% quantum efficiency, a dark count rate of 90 kHz, and a maximum count rate of 1 MHz. Recently, a fiber coupled avalanche photodiode (APD) operating in the geiger mode has been incorporated into the DIAL receiver. The APD has a quantum efficiency of 10%, a dark count rate of 10 kHz, and a maximum count rate of 1 MHz and provides a much larger dynamic range than the PMT. Both the PMT and APD provide TTL logic pulses that are monitored using a multichannel scaler card used to count the return photons as a function of time of flight and are thus interchangeable. The DIAL instrument was developed at the 1.571 m wavelength to take advantage of commercial-off-the-shelf components. The instrument is operated using a custom Labview program that switches to the DMLD operating at the on-line wavelength, locks this laser to a user defined wavelength setting, and collects return signals for a user defined time. The control program switches to the DMLD operating at the off-line wavelength where data is again collected for a user defined time. The control program repeats this process until stopped by the operator. The DIAL instrument has been operated at the Zero Emission Research Technology (ZERT) field site located on the Montana State University campus and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. Data collected by the DIAL instrument at both field sites demonstrate that the DIAL is capable of retrieving night time CO2 number density profiles out to a range of 2.5 km with a 150 m range resolution. The DIAL retrievals are validated using a co-located Li-COR 820 gas analyzer placed along the DIAL optical path allowing comparison at a single range as a function of time.

Real-time sensing of lint quality

USDA-ARS?s Scientific Manuscript database

Modem cotton gins have the purpose of extracting lint (the cotton) from trash and seeds- usually the sticks, leaves and burrs that are entrained with the cotton. These modem gins include many individual machine components that are operated sequentially to form the gin processing line. Recent on-line...

Satellite Data Transmission (SDT) requirement

NASA Technical Reports Server (NTRS)

Chie, C. M.; White, M.; Lindsey, W. C.

1984-01-01

An 85 Mb/s modem/codec to operate in a 34 MHz C-band domestic satellite transponder at a system carrier to noise power ratio of 19.5 dB is discussed. Characteristics of a satellite channel and the approach adopted for the satellite data transmission modem/codec selection are discussed. Measured data and simulation results of the existing 50 Mbps link are compared and used to verify the simulation techniques. Various modulation schemes that were screened for the SDT are discussed and the simulated performance of two prime candidates, the 8 PSK and the SMSK/2 are given. The selection process that leads to the candidate codec techniques are documented and the technology of the modem/codec candidates is assessed. Costs of the modems and codecs are estimated.

On Ramps: Options and Issues in Accessing the Internet.

ERIC Educational Resources Information Center

Bocher, Bob

1995-01-01

Outlines the basic options that schools and libraries have for accessing the Internet, focusing on four models: direct connection; dial access using SLIP/PPP (Serial Line Internet Protocol/Point-to-Point Protocol); dial-up using terminal emulation mode; and dial access through commercial online services. Discusses access option issues such as…

Optical Access Networks

NASA Astrophysics Data System (ADS)

Zheng, Jun; Ansari, Nirwan

2005-02-01

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks.

An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

PubMed Central

Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

2012-01-01

This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network. PMID:22969324

An ultra-low power and flexible acoustic modem design to develop energy-efficient underwater sensor networks.

PubMed

Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

2012-01-01

This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

The Installation of Satellite Modems on SEIS-UK Supported Remote Seismic Deployments

NASA Astrophysics Data System (ADS)

Horleston, A. C.; Brisbourne, A.; Hawthorn, D.

2006-12-01

SEIS-UK, as the UK's NERC funded national seismic equipment facility, is frequently involved in large, often remote, temporary seismic networks (running for up to 2 years). Up till now all these deployments have been managed solely by on-site maintenance but now SEIS-UK is investing in a number of satellite modems. The Michrosat 2400 OEM Modems, provided by Wireless Innovations Ltd, will be integrated within Guralp DCM data-logger units and will be used to provide regular state-of-health reports from remote networks. They will also provide the user the facility to communicate with the deployed systems, apply configuration changes and request system re-boots. This should lead to less instrument down-time and allow for more focussed site visits and thus, hopefully, reduce the cost (and servicing time) of remote installations. The Michrosat Modems are relatively low-powered and draw a maximum current of 2.5A (at 4.4v) for a few microseconds when initialising a call, dropping to bursts of approximately 1A when transmitting. This makes them ideally suited to temporary deployments relying on solar charged battery power. We will present examples of the configuration and typical deployment of the modems and the types of data transmitted.

Remote sensing of atmospheric NO2 by employing the continuous-wave differential absorption lidar technique.

PubMed

Mei, Liang; Guan, Peng; Kong, Zheng

2017-10-02

Differential absorption lidar (DIAL) technique employed for remote sensing has been so far based on the sophisticated narrow-band pulsed laser sources, which require intensive maintenance during operation. In this work, a continuous-wave (CW) NO 2 DIAL system based on the Scheimpflug principle has been developed by employing a compact high-power CW multimode 450 nm laser diode as the light source. Laser emissions at the on-line and off-line wavelengths of the NO 2 absorption spectrum are implemented by tuning the injection current of the laser diode. Lidar signals are detected by a 45° tilted area CCD image sensor satisfying the Scheimpflug principle. Range-resolved NO 2 concentrations on a near-horizontal path are obtained by the NO 2 DIAL system in the range of 0.3-3 km and show good agreement with those measured by a conventional air pollution monitoring station. A detection sensitivity of ± 0.9 ppbv at 95% confidence level in the region of 0.3-1 km is achieved with 15-minute averaging and 700 m range resolution during hours of darkness, which allows accurate concentration measurement of ambient NO 2 . The low-cost and robust DIAL system demonstrated in this work opens up many possibilities for field NO 2 remote sensing applications.

Two Wavelength Ti:sapphire Laser for Ozone DIAL Measurements from Aircraft

NASA Technical Reports Server (NTRS)

Situ, Wen; DeYoung, Russel J.

1998-01-01

Laser remote sensing of ozone from aircraft has proven to be a valuable technique for understanding the distribution and dynamics of ozone in the atmosphere. Presently the differential absorption lidar (DIAL) technique, using dual ND:YAG lasers that are doubled to pump dye lasers which in turn are doubled into the UV for the "on" and "off' line lasers, is used on either the NASA DC-8 or P-3 aircraft. Typically, the laser output for each line is 40-mJ and this is split into two beams, one looking up and the other downward, each beam having about 20-mJ. The residual ND:YAG (1.06 micron) and dye laser energies are also transmitted to obtain information on the atmospheric aerosols. While this system has operated well, there are several system characteristics that make the system less than ideal for aircraft operations. The system, which uses separate "on" and "off" line lasers, is quite large and massive requiring valuable aircraft volume and weight. The dye slowly degrades with time requiring replacement. The laser complexity requires a number of technical people to maintain the system performance. There is also the future interest in deploying an ozone DIAL system in an Unpiloted Atmospheric Vehicle (UAV) which would require a total payload mass of less than 150 kg and power requirement of less than 1500 W. A laser technology has emerged that could potentially provide significant enhancements over the present ozone DIAL system. The flashlamp pumped Ti:sapphire laser system is an emerging technology that could reduce the mass and volume over the present system and also provide a system with fewer conversion steps, reducing system complexity. This paper will discuss preliminary results from a flashlamp-pumped Ti:sapphire laser constructed as a radiation source for a UV DIAL system to measure ozone.

Development and Deployment of a Compact Eye-Safe Scanning Differential absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for Monitoring/Verification/Accounting at Geologic Sequestration Sites

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

Repasky, Kevin

2014-03-31

A scanning differential absorption lidar (DIAL) instrument for monitoring carbon dioxide has been developed. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the online absorption wavelength and the other operating at the offline wavelength. Two in-line fiber optic switches are used to switch between online and offline operation. After the fiber optic switch, an acousto- optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66more » {micro}J, a pulse repetition frequency of 15 kHz, and an operating wavelength of 1.571 {micro}m. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a photo-multiplier tube (PMT) module operating in the photon counting mode. The DIAL instrument has been operated from a laboratory environment on the campus of Montana State University, at the Zero Emission Research Technology (ZERT) field site located in the agricultural research area on the western end of the Montana State University campus, and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. DIAL data has been collected and profiles have been validated using a co-located Licor LI-820 Gas Analyzer point sensor.« less

Gay and bisexual men's use of the Internet: research from the 1990s through 2013.

PubMed

Grov, Christian; Breslow, Aaron S; Newcomb, Michael E; Rosenberger, Joshua G; Bauermeister, Jose A

2014-01-01

We document the historical and cultural shifts in how gay and bisexual men have used the Internet for sexuality between the 1990s and 2013-including shifting technology as well as research methods to study gay and bisexual men online. Gay and bisexual men have rapidly taken to using the Internet for sexual purposes: for health information seeking, finding sex partners, dating, cybersex, and pornography. Men have adapted to the ever-evolving technological advances that have been made in connecting users to the Internet-from logging on via dial-up modem on a desktop computer to geo-social-sexual networking via handheld devices. In kind, researchers have adapted to the Internet to study gay and bisexual men. Studies have carefully considered the ethics, feasibility, and acceptability of using the Internet to conduct research and interventions. Much of this work has been grounded in models of disease prevention, largely as a result of the ongoing HIV/AIDS epidemic. The need to reduce HIV in this population has been a driving force to develop innovative research and Internet-based intervention methodologies. The Internet, and specifically mobile technology, is an environment gay and bisexual men are using for sexual purposes. These innovative technologies represent powerful resources for researchers to study and provide outreach.

Development of High Data Rate Acoustic Multiple-Input/Multiple-Output Modems

DTIC Science & Technology

2015-09-30

communication capabilities of underwater platforms and facilitate real-time adaptive operations in the ocean. OBJECTIVES The ...signaling at the transmitter and low-complexity time reversal processing at the receiver. APPROACH Underwater acoustic (UWA) communication is useful...digital communications in shallow water environments. The advancement has direct impacts on defense appliations since underwater acoustic modems

FirstSearch and NetFirst--Web and Dial-up Access: Plus Ca Change, Plus C'est la Meme Chose?

ERIC Educational Resources Information Center

Koehler, Wallace; Mincey, Danielle

1996-01-01

Compares and evaluates the differences between OCLC's dial-up and World Wide Web FirstSearch access methods and their interfaces with the underlying databases. Also examines NetFirst, OCLC's new Internet catalog, the only Internet tracking database from a "traditional" database service. (Author/PEN)

Development and operation of a real-time data acquisition system for the NASA-LaRC differential absorption lidar

NASA Technical Reports Server (NTRS)

Butler, C.

1985-01-01

Computer hardware and software of the NASA multipurpose differential absorption lidar (DIAL) sysatem were improved. The NASA DIAL system is undergoing development and experimental deployment for remote measurement of atmospheric trace gas concentration from ground and aircraft platforms. A viable DIAL system was developed with the capability of remotely measuring O3 and H2O concentrations from an aircraft platform. Test flights were successfully performed on board the NASA/Goddard Flight Center Electra aircraft from 1980 to 1984. Improvements on the DIAL data acquisition system (DAS) are described.

Linear operating region in the ozone dial photon counting system

NASA Technical Reports Server (NTRS)

Andrawis, Madeleine

1995-01-01

Ozone is a relatively unstable molecule found in Earth's atmosphere. An ozone molecule is made up of three atoms of oxygen. Depending on where ozone resides, it can protect or harm life on Earth. High in the atmosphere, about 15 miles up, ozone acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. Without this shield, we would be more susceptible to skin cancer, cataracts, and impaired immune systems. Closer to Earth, in the air we breathe, ozone is a harmful pollutant that causes damage to lung tissue and plants. Since the early 1980's, airborne lidar systems have been used for making measurements of ozone. The differential absorption lidar (DIAL) technique is used in the remote measurement of O3. This system allows the O3 to be measured as function of the range in the atmosphere. Two frequency-doubled Nd:YAG lasers are used to pump tunable dye lasers. The lasers are operating at 289 nm for the DIAL on-line wavelength of O3, and the other one is operated at 300 nm for the off-line wavelength. The DIAL wavelengths are produced in sequential laser pulses with a time separation of 300 micro s. The backscattered laser energy is collected by telescopes and measured using photon counting systems. The photon counting system measures the light signal by making use of the photon nature of light. The output pulse from the Photo-Multiplier Tube (PE), caused by a photon striking the PMT photo-cathode, is amplified and passed to a pulse height discriminator. The peak value of the pulse is compared to a reference voltage (discrimination level). If the pulse amplitude exceeds the discrimination level, the discriminator generates a standard pulse which is counted by the digital counter. Non-linearity in the system is caused by the overlapping of pulses and the finite response time of the electronics. At low count rates one expects the system to register one event for each output pulse from the PMT corresponding to a photon incident upon the photocathode, however, at higher rates the limitations of the discrimination/counting system will cause the observed count rate to be non-linear with respect to the true count rate. Depending on the pulse height distribution and the discriminator level, the overlapping of pulses (pulse pile-up) can cause count loss or even an additional apparent count gain as the signal levels increase. Characterization of the system, including the pulse height distribution, the signal to noise ratio, and the effect of the discriminator threshold level, is critical in maximizing the linear operating region of the system, thus greatly increasing the useful dynamic range of the system.

The Challenge of Cyber Power for Central African Countries: Risks and Opportunities

DTIC Science & Technology

2012-12-01

decision makers to take the risk of deploying internal networks , which generally are exclusively wireless and rely on free, online messaging...provided to the population by nearly fifty129 operators, using a mosaic of technologies from dial- up to VSAT via wireless local loops. In the past...which is bracing up to adapt to the requirements of the information society.” In his address to the nation on 3 November 2004, in the wake of his

The Operational Use of an Automated High Frequency Radio System Incorporating Automatic Link Establishment and Single-Tone Serial Modem Technology for U.S. Navy Ship-Shore Communications

DTIC Science & Technology

1993-10-01

between the link chronologically in the following sections. quality analysis ( LQA ) score measured by ALE and single- tone serial modem performance. A...receiving ends in turn and (propagation permitting), pass traffic and terminate the are used to calculate a combined link quality analysis ( LQA ...score. The LQA score is displayed to the operator NCCOSC RDTE DIV installation team accomplished the as a number on an arbitrary scale of 0 to 120, with a

Telemetry Tracking and Control Through Commercial LEO Satellites

NASA Technical Reports Server (NTRS)

Streich, Ronald C.; Morgan, Dwayne R.; Bull, Barton B.; Grant, Charles E.; Powers, Edward I. (Technical Monitor)

2001-01-01

Personnel from the Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF in Virginia have successfully tested commercial LEO communications satellites for sounding rocket, balloon and aircraft flight TT&C. The Flight Modern became a GSFC/WFF Advanced Range Technology Initiative (ARTI) in an effort to streamline TT&C capability to the user community at low cost. Ground tests of the Flight Modem verified duplex communications quality of service and measured transmission latencies. These tests were completed last year and results reported in the John Hopkins University (JHU) Applied Physics Laboratory (APL) 4th International Symposium on Reducing Spacecraft Costs for Ground Systems and Operations. The second phase of the Flight Modem baseline test program was a demonstration of the ruggedized version of the WFF Flight Modem flown on a sounding rocket launched it the Swedish rocket range (Esrangc) near Kiruna, Sweden, with results contained in this paper. Aircraft flight tests have been and continue to be conducted. Flights of opportunity are being actively pursued with other centers, ranges and users at universities. The WFF Flight Modem contains a CPS receiver to provide vehicle position for tracking and vehicle recovery. The system architecture, which integrates antennas, CPS receiver, commercial satellite packet data modem and a single board computer with custom software, is described. Small satellite use of the WFF Flight Modem is also being investigated, The Flight Modem provides an independent vehicle position source for Range Safety applications. The LEO communication system contains a coarse position location system, which is compared to GPS ace acy. This comparison allows users, to determine the need for a CPS receiver in addition to the satellite packet data modem for their application.

High Power and Frequency-Agile Optical Parametric Oscillators for Airborne DIAL Measurements of CH4 and H2O

NASA Astrophysics Data System (ADS)

Nehrir, A. R.; Shuman, T.; Chuang, T.; Hair, J. W.; Refaat, T. F.; Ismail, S.; Kooi, S. A.; Notari, A.

2014-12-01

Atmospheric methane (CH4) has the second largest radiative forcing of the long-lived greenhouse gasses (GHG) after carbon dioxide. However, methane's much shorter atmospheric lifetime and much stronger warming potential make its radiative forcing equivalent to that for CO2 over a 20-year time horizon which makes CH4 a particularly attractive target for mitigation strategies. Similar to CH4, water vapor (H2O) is the most dominant of the short-lived GHG in the atmosphere and plays a key role in many atmospheric processes. Atmospheric H2O concentrations span over four orders of magnitude from the planetary boundary layer where high impact weather initiates to lower levels in the upper troposphere and lower stratosphere (UTLS) where water vapor has significant and long term impacts on the Earth's radiation budget. NASA Langley has fostered the technology development with Fibertek, Inc. to develop frequency agile and high power (> 3 W) pulsed lasers using similar architectures in the 1645 nm and 935 nm spectral bands for DIAL measurements of CH4 and H2O, respectively. Both systems utilize high power 1 kHz pulse repetition frequency Nd:YAG lasers to generate high power laser emission at the desired wavelength via optical parametric oscillators (OPO). The CH4 OPO, currently in its final build stage in a SBIR Phase II program has demonstrated >2 W average power with injection seeding from a distributed feedback (DFB) laser during risk reduction experiments. The H2O OPO has demonstrated high power operation (>2 W) during the SBIR Phase I program while being injection seeded with a DFB laser, and is currently funded via an SBIR Phase II to build a robust system for future integration into an airborne water vapor DIAL system capable of profiling from the boundary layer up to the UTLS. Both systems have demonstrated operation with active OPO wavelength control to allow for optimization of the DIAL measurements for operation at different altitudes and geographic regions. An update on the progress of the CH4 and H2O laser development will be presented which will focus on key laser characteristics such as pulse energy, frequency agility and spectral purity. DIAL simulations will also be presented based on the expected and measured laser characteristics and system parameters in anticipation of future system(s) development.

Phoenix Transit Sunday Dial-a-Ride

DOT National Transportation Integrated Search

1983-06-01

A local taxi operator began subsidized dial-a-ride service in Phoenix, AR, when the city found that Sunday fixed-route transit service would be more costly. Regular cabs and wheelchair vans are billed at a fixed hourly rate less fares collected. Over...

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.

Ground-based eye-safe networkable micro-pulse differential absorption and high spectral resolution lidar for water vapor and aerosol profiling in the lower troposphere

NASA Astrophysics Data System (ADS)

Repasky, K. S.; Spuler, S.; Hayman, M. M.; Bunn, C. E.

2017-12-01

Atmospheric water vapor is a greenhouse gas that is known to be a significant driver of weather and climate. Several National Research Council (NRC) reports have highlighted the need for improved water vapor measurements that can capture its spatial and temporal variability as a means to improve weather predictions. Researchers at Montana State University (MSU) and the National Center for Atmospheric Research (NCAR) have developed an eye-safe diode laser based micro-pulse differential absorption lidar (MP-DIAL) for water vapor profiling in the lower troposphere. The MP-DIAL is capable of long term unattended operation and is capable of monitoring water vapor in the lower troposphere in most weather conditions. Two MP-DIAL instruments are currently operational and have been deployed at the Front Range Air Pollution and Photochemistry Experiment (FRAPPE), the Plains elevated Convection at Night (PECAN) experiment, the Perdigão experiment, and the Land Atmosphere Feedback Experiment (LAFE). For each of these field experiments, the MP-DIAL was run unattended and provided near-continuous water vapor profiles, including periods of bright daytime clouds, from 300 m above the ground level to 4 km (or the cloud base) with 150 m vertical resolution and 5 minute temporal resolution. Three additional MP-DIAL instruments are currently under construction and will result in a network of five eye-safe MP-DIAL instruments for ground based weather and climate research experiments. Taking advantage of the broad spectral coverage and modularity or the diode based architecture, a high spectral resolution lidar (HSRL) measurement capabilities was added to the second MP-DIAL instrument. The HSRL capabilities will be operational during the deployment at the LAFE field experiment. The instrument architecture will be presented along with examples of data collected during recent field experiments.

A high speed sequential decoder

NASA Technical Reports Server (NTRS)

Lum, H., Jr.

1972-01-01

The performance and theory of operation for the High Speed Hard Decision Sequential Decoder are delineated. The decoder is a forward error correction system which is capable of accepting data from binary-phase-shift-keyed and quadriphase-shift-keyed modems at input data rates up to 30 megabits per second. Test results show that the decoder is capable of maintaining a composite error rate of 0.00001 at an input E sub b/N sub o of 5.6 db. This performance has been obtained with minimum circuit complexity.

Modem Characterization Through a Wideband, Hard-Limited Ka-Band Satellite Channel

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Ivancic, William; Tanger, Tom; Cronon, Chris; Lee, Donald; Kifer, David R.

1999-01-01

NASA is using a commercial customized TDMA/FDMA bandwidth on demand modem for use with the Advanced Communications Technology Satellite (ACTS) to highlight the numerous services and experiments that can be performed using small Ka-Band terminals. Characterizing the modems proved challenging due to the characteristics of the satellite transponder. The ACTS channel is hard-limited and up to 900 MHz wide. The channel has some unusual dynamic properties due to the satellite and antenna system, which make modem testing through the satellite challenging and the test requirements stringent. The satellite Multi-Beam Antenna (MBA) has a 1 hertz oscillation induced by the momentum wheel, which causes the transmit antenna pattern to move slightly. This results in a 1 hertz oscillation in the ground station receive power, with amplitude changes up to 1 dB depending on terminal location within a spot beam and associated gain slope. In addition, ACTS experiences a solar induced "thermal event" each day. This "thermal event" occurs when the sun heats the antenna support structure causing the transmit and receive reflectors to mispoint. This results in a slowly decreasing or increasing power density at the ground station receiver as the antenna pattern moves off bore-site. This paper describes the method used to fully characterize the TDMA/FDMA modem through the ACTS wideband, hard-limited transponder. In particular, techniques are discussed for conducting RF measurements on such a channel, the affect that the thermal characteristics and 1 hertz variations have on the accuracy of the results, and suggested means to minimize the error and provide useful and valuable data.

Distributed Sensor Systems and Electromechanical Analog Facility

DTIC Science & Technology

1980-01-01

interfaces (parallel I/O, modems , etc.) real time operating systems (perhaps a short survey of what is available in the industry today), data...consists of a LSI-11 microprocessor, 56K bytes of memory, and serial and parallel I/O boards. 2.1.7 Disk controller The standard disk controller...with MTS via the modems connected to the LSI-lls. This pseudodevice cannot be reassigned. OSWIT I/O AND INTERRUPT STRUCTURE 137 OSWIT

Differential Absorption Lidar (DIAL) Measurements of Landfill Methane Emissions

NASA Astrophysics Data System (ADS)

Innocenti, Fabrizio; Robinson, Rod; Gardiner, Tom; Finlayson, Andrew; Connor, Andy

2017-04-01

DIFFERENTIAL ABSORPTION LIDAR (DIAL) MEASURMENTS OF LANDFILL METHANE EMISSIONS F. INNOCENTI *, R.A. ROBINSON *, T.D. GARDINER, A. FINLAYSON *, A. CONNOR* * National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom Methane is one of the most important gaseous hydrocarbon species for both industrial and environmental reasons. Understanding and quantifying methane emissions to atmosphere is an important element of climate change research. Range-resolved infrared Differential Absorption Lidar (DIAL) measurements provide the means to map and quantify a wide range of different methane sources. DIAL is a powerful technique that can be used to track and quantify plumes emitted from area emission sources such as landfill sites, waste water treatment plants and petrochemical plants. By using lidar (light detection and ranging), the DIAL technique is able to make remote range-resolved single-ended measurements of the actual distribution of target gases in the atmosphere, with no disruption to normal site operational activities. DIAL provides 3D mapping of emission concentrations and quantification of emission rates for a wide range of target gases such as methane. The NPL DIAL laser source is operated alternately at two similar wavelengths. One of these, termed the "on-resonant wavelength", is chosen to be at a wavelength which is absorbed by the target species. The other, the "off-resonant wavelength", is chosen to be at a nearby wavelength which is not absorbed significantly by the target species. The two wavelengths are chosen to be close, so that the atmospheric scattering properties are the same for both wavelengths. They are also chosen so that any differential absorption due to other atmospheric species are minimised. Any measured difference in the returned signals is therefore due to absorption by the target gas. In the typical DIAL measurement configuration the mobile DIAL facility is positioned downwind of the area being investigated. The DIAL laser beam is then scanned in a vertical plane and the distribution of the target gas in the measurement plane is mapped. By combining this information with the wind conditions, the technique provides a direct measure of the emission rate of the target gas and its spatial distribution rather than the path-averaged concentration given by most other optical remote sensing methods. This means that localised, high concentration plumes can be discriminated from broad, low concentration plumes, and that emissions from different sources within an area can be spatially separated and independently quantified. As an example, the localised emission from an engine stack or flare can be separated from the diffuse emission from a capped area. Horizontal scans just above the surface can also be performed and they are generally used to identify emission hot-spots. Over the last decade the NPL DIAL system has carried out landfill emission surveys at over thirty sites in the UK, France and the USA measuring the total site and area-specific emissions from e.g. active areas, capped areas and engine stacks. This history of emissions measurements made with DIAL at landfill sites is testament to the maturity of the technique that can be deployed as reference tool by the waste industry. The DIAL data can be used by the site operators to validate emissions estimates and by the regulators to revise and update the emission inventories.

Mid-IR DIAL for high-resolution mapping of explosive precursors

NASA Astrophysics Data System (ADS)

Mitev, V.; Babichenko, S.; Bennes, J.; Borelli, R.; Dolfi-Bouteyre, A.; Fiorani, L.; Hespel, L.; Huet, T.; Palucci, A.; Pistilli, M.; Puiu, A.; Rebane, O.; Sobolev, I.

2013-10-01

A DIAL instrument on a moving platform is seen as a valuable remote sensing component in a sensor network for area monitoring, targeting sites involved in unauthorised explosive manufacturing. Such instrument will perform the area mapping of the vapour concentration of key substances, known to be used as precursors in explosive fabrication, such as acetone and nitromethane. The IR spectra of acetone and nitromethane vapours have been defined from available spectroscopy databases and from laboratory measurements as showing optimal spectral band for the DIAL operation in the spectral range of 3.0 μm - 3.5 μm. The DIAL operation has been numerically simulated, with inputs based on the HITRAN database, the U.S. Standard Atmosphere and aerosol simulation software package OPAC. A combination of OPO and OPA has been chosen as a transmitter, where the idler wavelength is used for probing, with wavelength tuning in sequence. A scanner mounted on top of the coaxially aligned laser and receiver, is capable of covering almost 360 degrees horizontally and +/-30 degrees vertically. The detection is performed by a photovoltaic photodiode with 4-stage cooling, with a signal digitalisation having 14 bit amplitude resolution and 125 Ms/s sampling rate. Here we present the development and the first test of the DIAL instrument.

Flight test results for the Digital Integrated Automatic Landing Systems (DIALS): A modern control full-state feedback design

NASA Technical Reports Server (NTRS)

Hueschen, R. M.

1984-01-01

The Digital Integrated Automatic Landing System (DIALS) is discussed. The DIALS is a modern control theory design performing all the maneuver modes associated with current autoland systems: localizer capture and track, glideslope capture and track, decrab, and flare. The DIALS is an integrated full-state feedback system which was designed using direct-digital methods. The DIALS uses standard aircraft sensors and the digital Microwave Landing System (MLS) signals as measurements. It consists of separately designed longitudinal and lateral channels although some cross-coupling variables are fed between channels for improved state estimates and trajectory commands. The DIALS was implemented within the 16-bit fixed-point flight computers of the ATOPS research aircraft, a small twin jet commercial transport outfitted with a second research cockpit and a fly-by-wire system. The DIALS became the first modern control theory design to be successfully flight tested on a commercial-type aircraft. Flight tests were conducted in late 1981 using a wide coverage MLS on Runway 22 at Wallops Flight Center. All the modes were exercised including the capture and track of steep glidescopes up to 5 degrees.

Asynchronous timing and Doppler recovery in DSP based DPSK modems for fixed and mobile satellite applications

NASA Astrophysics Data System (ADS)

Koblents, B.; Belanger, M.; Woods, D.; McLane, P. J.

While conventional analog modems employ some kind of clock wave regenerator circuit for synchronous timing recovery, in sampled modem receivers the timing is recovered asynchronously to the incoming data stream, with no adjustment being made to the input sampling rate. All timing corrections are accomplished by digital operations on the sampled data stream, and timing recovery is asynchronous with the uncontrolled, input A/D system. A good timing error measurement algorithm is a zero crossing tracker proposed by Gardner. Digital, speech rate (2400 - 4800 bps) M-PSK modem receivers employing Gardner's zero crossing tracker were implemented and tested and found to achieve BER performance very close to theoretical values on the AWGN channel. Nyguist pulse shaped modem systems with excess bandwidth factors ranging from 100 to 60 percent were considered. We can show that for any symmetric M-PSK signal set Gardner's NDA algorithm is free of pattern jitter for any carrier phase offset for rectangular pulses and for Nyquist pulses having 100 percent excess bandwidth. Also, the Nyquist pulse shaped system is studied on the mobile satellite channel, where Doppler shifts and multipath fading degrade the pi/4-DQPSK signal. Two simple modifications to Gardner's zero crossing tracker enable it to remain useful in the presence of multipath fading.

Asynchronous timing and Doppler recovery in DSP based DPSK modems for fixed and mobile satellite applications

NASA Technical Reports Server (NTRS)

Koblents, B.; Belanger, M.; Woods, D.; Mclane, P. J.

1993-01-01

While conventional analog modems employ some kind of clock wave regenerator circuit for synchronous timing recovery, in sampled modem receivers the timing is recovered asynchronously to the incoming data stream, with no adjustment being made to the input sampling rate. All timing corrections are accomplished by digital operations on the sampled data stream, and timing recovery is asynchronous with the uncontrolled, input A/D system. A good timing error measurement algorithm is a zero crossing tracker proposed by Gardner. Digital, speech rate (2400 - 4800 bps) M-PSK modem receivers employing Gardner's zero crossing tracker were implemented and tested and found to achieve BER performance very close to theoretical values on the AWGN channel. Nyguist pulse shaped modem systems with excess bandwidth factors ranging from 100 to 60 percent were considered. We can show that for any symmetric M-PSK signal set Gardner's NDA algorithm is free of pattern jitter for any carrier phase offset for rectangular pulses and for Nyquist pulses having 100 percent excess bandwidth. Also, the Nyquist pulse shaped system is studied on the mobile satellite channel, where Doppler shifts and multipath fading degrade the pi/4-DQPSK signal. Two simple modifications to Gardner's zero crossing tracker enable it to remain useful in the presence of multipath fading.

From Revolution to Evolution: 21 Years of the IRIS Data Management Facility

NASA Astrophysics Data System (ADS)

Benson, R. B.; Ahern, T. K.; Trabant, C. M.; Casey, R.

2009-12-01

A revolution is defined as a "drastic and far-reaching change in the way of thinking and behaving", and this describes the effect that the IRIS Data Management System (DMS) has had in the framework of seismological research. The IRIS Data Management Center (DMC) prototype began operation at theUniversity of Texas at Austin in 1988 and has evolved to to a fully functioning facility at the University of Washington in Seattle. The focus of this submission is to share an historical timeline of events related to the DMC, a bit of scrap-booking perhaps, centered around the business of waveform data management conducted by IRIS and it's partners. We hope to illustrate how the successful philosophy of sharing unrestricted data, openly collaborating with a global network of networks, and partnering with computer and software industry vendors that have supported our community's academic research, has enabled generations of seismologists to both curate and continually "mine" the ever-growing 45 years of digital data currently stored in the perpetual archive located in Seattle, WA. At the time that the Loma Prieta Earthquake shook and burned San Francisco on October 17, 1989, there were only 3 stations which had dial-up modems enabling what then was considered "fast access" to waveform data delivery from them back to the DMC. This was considered the first test of the DMC, since waveform data were collected and distributed within days of this event. But this was only a foretelling of things to come, since the rates of archiving and distribution have continually grown to a current 1900+ stations and a 17,000+ channel count of real-time data streaming in and out of the DMC daily, totaling 50 Terabytes of data shipped in 2009 alone. We will attempt to summarize the important technological challenges, solutions, and growth of the DMC with the goal of illustrating that "if you build it, they will come", and how this could be useful to other organizations.

1.6μm DIAL System for Measurements of CO2 Concentration Profiles in the Atmosphere

NASA Astrophysics Data System (ADS)

Nagasawa, C.; Abo, M.; Shibata, Y.

2013-12-01

We have developed a direct detection 1.6 μm differential absorption lidar (DIAL) technique to perform range-resolved measurements of vertical CO2 concentration profiles in the atmosphere. Our 1.6 μm DIAL system has a 60 cm telescope for vertical measurement and a 25 cm scanning telescope for horizontal measurement. This 1.6 μm DIAL system is also available to measure CO2 concentration profiles for daytime by using narrow-band interference filters. The 1.6 μm DIAL measurement was achieved successfully the vertical CO2 profile up to 7 km altitude with an error less than 1.0 % by integration time of 30 minutes and vertical resolution of 300 - 600 m. The CO2 DIAL was also operated with the range-height indicator (RHI) mode, and the 2-D measurement provided inhomogeneity in the boundary layer. The vertical distribution of CO2 concentration from 2 km to 7 km altitude has been observed using two telescopes with different apertures. We hope to get the data of the CO2 concentration from lower altitude to 7 km at the same time. Since the change of signal intensity is larger near the ground, it is also important to the install the photon counter with the faster count rate to expand the dynamic range. The high speed counter and the telescope system make the dynamic range expand more than 10 times and the vertical distribution observation of CO2 concentration from 0.5 km to 7 km altitude is performed. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References Sakaizawa, D., C. Nagasawa, T. Nagai, M. Abo, Y. Shibata, H. Nagai, M. Nakazato, and T. Sakai, Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric oscillator and photon-counting detector for the vertical CO2 profile, Applied Optics, Vol.48, No.4, pp. 748-757, 2009. Stephens, B. B. et al., Weak Northern and Strong Tropical Land Carbon Uptake from Vertical Profiles of Atmospheric CO2, Science 316, pp. 1732-1735, 2007.

[Modern concepts of trauma care and multiple trauma management in oral and maxillofacial region].

PubMed

Tan, Yinghui

2015-06-01

Multiple trauma management requires the application of modem trauma care theories. Optimal treatment results can be achieved by reinforcing cooperation and stipulating a treatment plan together with other disciplines. Based on modem theories in trauma care and our understanding of the theoretical points, this paper analyzes the injury assessment strategies and methods in oral and maxillofacial multiple trauma management. Moreover, this paper discusses operating time and other influencing factors as well as proposed definitive surgical timing and indications in comprehensive management of oral and maxillofacial multiple trauma patients associated with injuries in other body parts. We hope that this paper can help stomatological physicians deepen their understanding of modem trauma care theories and improve their capacity and results in the treatment of oral and maxillofacial multiple trauma.

FIR Filter of DS-CDMA UWB Modem Transmitter

NASA Astrophysics Data System (ADS)

Kang, Kyu-Min; Cho, Sang-In; Won, Hui-Chul; Choi, Sang-Sung

This letter presents low-complexity digital pulse shaping filter structures of a direct sequence code division multiple access (DS-CDMA) ultra wide-band (UWB) modem transmitter with a ternary spreading code. The proposed finite impulse response (FIR) filter structures using a look-up table (LUT) have the effect of saving the amount of memory by about 50% to 80% in comparison to the conventional FIR filter structures, and consequently are suitable for a high-speed parallel data process.

Bi-directional communication interface for microprocessor-to-system/370

NASA Technical Reports Server (NTRS)

Fischer, J. P.

1981-01-01

The design and operation of a bi-directional communication interface between a microcomputer and the IBM System/370 is documented. The hardware unit interconnects a modem to interface to the S/370, the microcomputer with an EIA I/O port, and a terminal for sending and receiving data from either the microcomputer or the S/370. Also described is the software necessary for the two-way interface. This interface is designed so that no modifications need to be made to the terminal, modem, or microcomputer.

Study of Potential Standardization of Digital Freeze Frame Video Codecs.

DTIC Science & Technology

1984-01-01

and MAR track an input clock over a very wide range. These are dependent on the modem used in any specific application. Interface connectors are those...terminals, 56K bit digital transmission sets). We have a limited custan capability and are not in the custom unit business. 1.,o .2e e.. , , 4g..2. . j...will) are designed for narrowband operation. We build our own modems which send .’e- pixels at a rate of 1969 pixels/second. Grey scale information is

Performance Evaluation of Data Modems for the Aeronautical Satellite Channel.

DOT National Transportation Integrated Search

1975-09-01

Several modems and satellite subsystems were tested with the aid of an aeronautical channel simulation facility. The modems tested included a high performance DPSK modem, a high performance CPSK modem, two hybird voice/data modems, and a lower perfor...

A measurement-driven approach to assess power line telecommunication (PLT) network quality of service (QoS) performance parameters

NASA Astrophysics Data System (ADS)

Betta, G.; Capriglione, D.; Ferrigno, L.; Laracca, M.

2009-10-01

Power line telecommunication (PLT) technology offers cheap and fast ways for providing in-home broadband services and local area networking. Its main advantage is due to the possibility of using the pre-existing electrical grid as a communication channel. Nevertheless, technical challenges arise from the difficulty of operating on a hostile medium, not designed for communication purposes, characterized by complex channel modeling and by varying time response. These aspects put practical problems for designers and testers in the assessment of network quality of service performance parameters such as the throughput, the latency, the jitter, and the reliability. The measurement of these parameters has not yet been standardized so that there do not exist reference test set-ups and measurement methodologies (i.e. the type of isolation from the ac main, the observation time and the number of experiments, the measurement uncertainty and so on). Consequently, experiments executed by adopting different methods may lead to incompatible measurement results, thus making it also impossible to have reliable comparisons of different PLT modems. Really, the development of standard procedures is a very difficult task because the scenarios in which the PLT modems can work are very wide and then the application of an exhaustive approach (in which all the parameters influencing the PLT performance should be considered) would be very complex and time consuming, thus making the modem characterization very expensive. In this paper, the authors propose a methodological approach to develop an efficient measurement procedure able to reliably assess the performance of PLT modems (in terms of network quality of service parameters) with a minimum number of experiments. It is based on both creating a reconfigurable grid to which real disturbing loads are connected and implementing an original design of the experiment technique based on the effects of the uncertainty of the measurement results. Methods are also provided to analyze measurement results and to estimate the measurement uncertainty.

Diode-laser-based water vapor differential absorption lidar (DIAL) profiler evaluation

NASA Astrophysics Data System (ADS)

Spuler, S.; Weckwerth, T.; Repasky, K. S.; Nehrir, A. R.; Carbone, R.

2012-12-01

We are in the process of evaluating the performance of an eye-safe, low-cost, diode-laser-based, water vapor differential absorption lidar (DIAL) profiler. This class of instrument may be capable of providing continuous water vapor and aerosol backscatter profiles at high vertical resolution in the atmospheric boundary layer (ABL) for periods of months to years. The technology potentially fills a national long term observing facility gap and could greatly benefit micro- and meso-meteorology, water cycle, carbon cycle and, more generally, biosphere-hydrosphere-atmosphere interaction research at both weather and climate variability time scales. For the evaluation, the Montana State University 3rd generation water vapor DIAL was modified to enable unattended operation for a period of several weeks. The performance of this V3.5 version DIAL was tested at MSU and NCAR in June and July of 2012. Further tests are currently in progress with Howard University at Beltsville, Maryland; and with the National Weather Service and Oklahoma University at Dallas/Fort Worth, Texas. The presentation will include a comparison of DIAL profiles against meteorological "truth" at the aforementioned locations including: radiosondes, Raman lidars, microwave and IR radiometers, AERONET and SUOMINET systems. Instrument reliability, uncertainty, systematic biases, detection height statistics, and environmental complications will be evaluated. Performance will be judged in the context of diverse scientific applications that range from operational weather prediction and seasonal climate variability, to more demanding climate system process studies at the land-canopy-ABL interface. Estimating the extent to which such research and operational applications can be satisfied with a low cost autonomous network of similar instruments is our principal objective.

Low-Power Direct-Sequence Spread-Spectrum Modem Architecture for Distributed Wireless Sensor Networks

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

Chien, C; Elgorriaga, I; McConaghy, C

2001-07-03

Emerging CMOS and MEMS technologies enable the implementation of a large number of wireless distributed microsensors that can be easily and rapidly deployed to form highly redundant, self-configuring, and ad hoc sensor networks. To facilitate ease of deployment, these sensors should operate on battery for extended periods of time. A particular challenge in maintaining extended battery lifetime lies in achieving communications with low power. This paper presents a direct-sequence spread-spectrum modem architecture that provides robust communications for wireless sensor networks while dissipating very low power. The modem architecture has been verified in an FPGA implementation that dissipates only 33 mWmore » for both transmission and reception. The implementation can be easily mapped to an ASIC technology, with an estimated power performance of less than 1 mW.« less

Development of differential absorption lidar (DIAL) for detection of CO2, CH4 and PM in Alberta

NASA Astrophysics Data System (ADS)

Wojcik, Michael; Crowther, Blake; Lemon, Robert; Valupadas, Prasad; Fu, Long; Leung, Bonnie; Yang, Zheng; Huda, Quamrul; Chambers, Allan

2005-05-01

Rapid expansion of the oil and gas industry in Alberta, including the oil sands, has challenged the Alberta Government to keep pace in its efforts to monitor and mitigate the environmental impacts of development. The limitations of current monitoring systems has pushed the provincial government to seek out advanced sensing technologies such as satellite imagery and laser based sensors. The Space Dynamics Laboratory (SDL) of Utah State University, in cooperation with Alberta Environmental Monitoring, Evaluation and Reporting Agency (AEMERA), has developed North America's first mobile differential absorption lidar (DIAL) system designed specifically for emissions measurement. This instrument is housed inside a 36' trailer which allows for mobility to travel across Alberta to characterize source emissions and to locate fugitive leaks. DIAL is capable of measuring concentrations for carbon dioxide (CO2) and methane (CH4) at ranges of up to 3 km with a spatial resolution of 10 meters. DIAL can map both CO2 and CH4, as well as particulate matter (PM) in a linear fashion; by scanning the laser beam in both azimuth and elevation DIAL can create images of emissions in two dimensions. DIAL imagery may be used to understand and control production practices, characterize source emissions, determine emission factors, locate fugitive leaks, assess plume dispersion, and confirm air dispersion modeling. A system overview of the DIAL instrument and some representative results will be discussed.

Emerging solid-state laser technology by lidar/DIAL remote sensing

NASA Technical Reports Server (NTRS)

Killinger, Dennis

1992-01-01

Significant progress has been made in recent years in the development of new, solid-state laser sources. This talk will present an overview of some of the new developments in solid-state lasers, and their application toward lidar/DIAL measurements of the atmosphere. Newly emerging lasers such as Ho:YAG, Tm:YAG, OPO, and Ti:Sapphire will be covered, along with the spectroscopic parameters required for differential operational modes of atmospheric remote sensing including Doppler-Windshear lidar, Tunable laser detection of water/CO2, and broad linewidth OPO's for open path detection of pollutant hydrocarbon gases. Additional considerations of emerging laser technology for lidar/DIAL will also be covered.

Airborne water vapor DIAL research: System development and field measurements

NASA Technical Reports Server (NTRS)

Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

1992-01-01

This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

Two-Way Radio Modem Data Transfer for Newborn Hearing Screening Devices.

PubMed

Matulat, Peter; Lepper, Ingo; Böttcher, Peter; Parfitt, Ross; Oswald, Hans; Am Zehnhoff-Dinnesen, Antoinette; Deuster, Dirk

2017-01-01

The success of a newborn hearing screening program depends on successful tracking and follow-up to ensure that children who have had positive screening results in the first few days of life receive appropriate and timely diagnostic and intervention services. The easy availability, through a suitable infrastructure, of the data necessary for the tracking, diagnosis, and care of children concerned is a major key to enhancing the quality and efficiency of newborn hearing screening programs. Two systems for the automated two-way transmission of newborn hearing screening and configuration data, based on mobile communication technology, for the screening devices MADSEN AccuScreen ® and Natus Echo-Screen ® were developed and tested in a field study. Radio modem connections were compared with conventional analogue modem transmissions from Natus Echo-Screen devices for duration, transmission rate, number of lost connections, and frequency of use. The average session duration was significantly lower with the MADSEN AccuScreen (12 s) and Natus Echo-Screen both with radio modem (15 s) than the Natus Echo-Screen with analogue modem (108 s). The transmission rate was significantly higher (898 and 1,758 vs. 181 bytes/s) for the devices with radio modems. Both radio modem devices had significantly lower rates of broken connections after initial connection (2.1 and 0.9 vs. 5.5%). An increase in the frequency of data transmission from the clinics with mobile radio devices was found. The use of mobile communication technology in newborn hearing screening devices offers improvements in the average session duration, transmission rate, and reliability of the connection over analogue solutions. We observed a behavioral change in clinical staff using the new technology: the data exchange with the tracking center is more often used. The requirements for on-site support were reduced. These savings outweigh the small increase in costs for the Internet service provider.

PILOT: A Precision Intercoastal Loran Translocator. Volume 3. Software.

DTIC Science & Technology

1982-03-01

includes a second loran receiver (for cross chain operation), an interface or modem for remotely entering TD bias values, and a printer. b. The nucleus...developing an interface board to connect to the ship’s gyro, and a TD bias modem or box, replacing the large general purpose keyboard with a small predefined...The PILOT program has divided this memory into 8K of RAM and 56K of EPROM. Of the 56K bytes of EPROM, 40K are HP code and 16K are PILOT code (see Fig. 3

Effects of ocean thermocline variability on noncoherent underwater acoustic communications.

PubMed

Siderius, Martin; Porter, Michael B; Hursky, Paul; McDonald, Vincent

2007-04-01

The performance of acoustic modems in the ocean is strongly affected by the ocean environment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by the ocean surface. The combined effects of these and other processes on modem performance are not well understood. The authors have been conducting experiments to study these environmental effects on various modulation schemes. Here the focus is on the role of the thermocline on a widely used modulation scheme (frequency-shift keying). Using data from a recent experiment conducted in 100-m-deep water off the coast of Kauai, HI, frequency-shift-key modulation performance is shown to be strongly affected by diurnal cycles in the thermocline. There is dramatic variation in performance (measured by bit error rates) between receivers in the surface duct and receivers in the thermocline. To interpret the performance variations in a quantitative way, a precise metric is introduced based on a signal-to-interference-noise ratio that encompasses both the ambient noise and intersymbol interference. Further, it will be shown that differences in the fading statistics for receivers in and out of the thermocline explain the differences in modem performance.

Integrating stochastic time-dependent travel speed in solution methods for the dynamic dial-a-ride problem.

PubMed

Schilde, M; Doerner, K F; Hartl, R F

2014-10-01

In urban areas, logistic transportation operations often run into problems because travel speeds change, depending on the current traffic situation. If not accounted for, time-dependent and stochastic travel speeds frequently lead to missed time windows and thus poorer service. Especially in the case of passenger transportation, it often leads to excessive passenger ride times as well. Therefore, time-dependent and stochastic influences on travel speeds are relevant for finding feasible and reliable solutions. This study considers the effect of exploiting statistical information available about historical accidents, using stochastic solution approaches for the dynamic dial-a-ride problem (dynamic DARP). The authors propose two pairs of metaheuristic solution approaches, each consisting of a deterministic method (average time-dependent travel speeds for planning) and its corresponding stochastic version (exploiting stochastic information while planning). The results, using test instances with up to 762 requests based on a real-world road network, show that in certain conditions, exploiting stochastic information about travel speeds leads to significant improvements over deterministic approaches.

Development of the Lidar Atmospheric Sensing Experiment (LASE): An Advanced Airborne DIAL Instrument

NASA Technical Reports Server (NTRS)

Moore, Alvah S., Jr.; Brown, Kevin E.; Hall, William M.; Barnes, James C.; Edwards, William C.; Petway, Larry B.; Little, Alan D.; Luck, William S., Jr.; Jones, Irby W.; Antill, Charles W., Jr.

1997-01-01

The Lidar Atmospheric Sensing Experiment (LASE) Instrument is the first fully-engineered, autonomous Differential Absorption Lidar (DIAL) System for the measurement of water vapor in the troposphere (aerosol and cloud measurements are included). LASE uses a double-pulsed Ti:Sapphire laser for the transmitter with a 30 ns pulse length and 150 mJ/pulse. The laser beam is "seeded" to operate on a selected water vapor absorption line in the 815-nm region using a laser diode and an onboard absorption reference cell. A 40 cm diameter telescope collects the backscattered signals and directs them onto two detectors. LASE collects DIAL data at 5 Hz while onboard a NASA/Ames ER-2 aircraft flying at altitudes from 16-21 km. LASE was designed to operate autonomously within the environment and physical constraints of the ER-2 aircraft and to make water vapor profile measurements across the troposphere to better than 10% accuracy. LASE has flown 19 times during the development of the instrument and the validation of the science data. This paper describes the design, operation, and reliability of the LASE Instrument.

Apparatus for fixing latency

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

Hall, David R; Bartholomew, David B; Moon, Justin

2009-09-08

An apparatus for fixing computational latency within a deterministic region on a network comprises a network interface modem, a high priority module and at least one deterministic peripheral device. The network interface modem is in communication with the network. The high priority module is in communication with the network interface modem. The at least one deterministic peripheral device is connected to the high priority module. The high priority module comprises a packet assembler/disassembler, and hardware for performing at least one operation. Also disclosed is an apparatus for executing at least one instruction on a downhole device within a deterministic region,more » the apparatus comprising a control device, a downhole network, and a downhole device. The control device is near the surface of a downhole tool string. The downhole network is integrated into the tool string. The downhole device is in communication with the downhole network.« less

Real-time Kinematics Base Station and Survey Unit Setup Method for the Synchronous Impulse Reconstruction (SIRE) Radar

DTIC Science & Technology

2012-12-01

GPS receiver, the Ashtech ProMark 500; a 3.4-GHz radio modem, the FreeWave 3400-SMR; a display unit, the Magellan MobileMapper CX; a 12-V battery pack...Figure 8. Bottom view of the ProMark 500. 3.1 Survey Unit RTK GPS Setup The following are the procedures for setting up...the RTK GPS Survey Unit: 1. Connect the radio modem to the ProMark 500 with serial cable #7 and #8. Display Screen Scroll Button Power LED Log

Measurements of CO2 Concentration and Wind Profiles with A Scanning 1.6μm DIAL

NASA Astrophysics Data System (ADS)

Abo, M.; Shibata, Y.; Nagasawa, C.; Nagai, T.; Sakai, T.; Tsukamoto, M.

2012-12-01

Horizontal carbon dioxide (CO2) distribution and wind profiles are important information for understanding of the regional sink and source of CO2. The differential absorption lidar (DIAL) and the Doppler lidar with the range resolution is expected to bring several advantages over passive measurements. We have developed a new scanning 1.6μm DIAL and incoherent Doppler lidar system to perform simultaniously measurements of CO2 concentration and wind speed profiles in the atmosphere. The 1.6μm DIAL and Doppler lidar system consists of the Optical Parametric Generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz). The receiving optics include the near-infrared photomultiplier tube with high quantum efficiency operating at the photon counting mode, a fiber Bragg grating (FBG) filter to detct Doppler shift, and a 25 cm telescope[1][2]. Laser beam is transmitted coaxially and motorized scanning mirror system can scan the laser beam and field of view 0-360deg horizontally and 0-52deg vertically. We report the results of vertical CO2 scanning measurenents and vertical wind profiles. The scanning elevation angles were from 12deg to 24deg with angular step of 4deg and CO2 concentration profiles were obtained up to 1 km altitude with 200 m altitude resolution. We also obtained vertical wind vector profiles by measuring line-of-sight wind profiles at two azimuth angles with a fixed elevation angle 52deg. Vertical wind vector profiles were obtained up to 5 km altitude with 1 km altitude rasolution. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References [1] L. B. Vann, et al., "Narrowband fiber-optic phase-shifted Fabry-Perot Bragg grating filters for atmospheric water vapor lidar measurements", Appl. Opt., 44, pp. 7371-7377 (2005). [2] Y. Shibata, et al., "1.5μm incoherent Doppler lidar using a FBG filter", Proceedings of 25th International Laser Radar Conference (ILRC25), pp. 338-340 (2010)

Infrared transmission of electronic information via LAN in the operating room.

PubMed

Hagihira, S; Takashina, M; Mori, T; Taenaka, N; Mashimo, T; Yoshiya, I

2000-01-01

Recent advances in technology have brought many kinds of monitoring devices into the operating room (OR). The information gathered by monitors can be channeled to the operating ward information system via a local area network (LAN). Connecting patients to monitors and monitors to the LAN, however, requires a large number of cables. This wiring is generally inconvenient and particularly troublesome if the layout of the OR is rearranged. From this point of view, wireless transmission seems ideally suited to clinical settings. Currently, two modes of wireless connectivity are available: radio-frequency (RF) waves or infrared (IR) waves. Some reports suggest that RF transmission is likely to cause electromagnetic interference (EMI) in medical devices such as cardiac pacemakers or infusion pumps. The risk of malfunctioning life-sustaining devices and the catastrophic consequences this would have on seriously ill patients rules out the use of RF. Here, we report an IR system using IR modems for LAN connectivity in the OR. In this study, we focused on the possible detrimental effects of EMI during wireless connectivity. In our trial, we found no evidence of EMI of IR modems with any of the medical devices we tested. Furthermore, IR modems showed similar performance to a wired system even in an electrically noisy environment. We conclude that IR wireless connectivity can be safely and effectively used in ORs.

Remote monitoring of sub ppb levels of vinyl chloride, dichloroethylene and trichloroethylene via modem operated automated GC

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

Linenberg, A.; Lander, N.J.

1994-12-31

The need for remote monitoring of certain compounds in a sparsely populated area with limited user assistance led to the development and manufacture of a self contained, portable gas chromatography with the appropriate software. Part per billion levels of vinyl chloride, cis 1,2 dichloroethylene and trichloroethylene were detected in air using a trap for preconcentration of the compounds. The units were continuously calibrated with certified standards from Scott Specialty Gases, which in one case was 1 part per billion of the aforementioned compounds. The entire operation of the units, including monitoring instrument responses, changing operating parameters, data transfer, data reviewmore » and data reporting was done entirely on a remote basis from approximately 600 miles away using a remote computer with a modem and remote operating software. The entire system concept promises the availability of highly sensitive remote monitoring in sparsely populated areas for long periods of time.« less

A novel high-speed PLC communication modem

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

Abraham, K.C.; Roy, S.

1992-10-01

In this paper an innovative design for power line carrier (PLC) communication using digitally modulated signals is presented. The major contribution consists of a new signal coupler to the power line that achieves a stable transmission bandwidth of 4 KHz on distribution lines over long distances. Preliminary field tests achieved half-duplex operation at 1.2 Kbaud over a distribution power line to the 120V network and back with a symbol error rate of about 2% using less than about 10 W of average transmitted power, which is considerably superior to the present state-of-the-art PLC modems. Full-duplex operation over 120/240V intra-building wiringmore » has also been field tested at 9.6 Kbaud over distances of 3000 ft. using 1W of average transmitted power.« less

Development of an Airborne Micropulse Water Vapor DIAL

NASA Astrophysics Data System (ADS)

Nehrir, A. R.; Ismail, S.

2012-12-01

Water vapor plays a key role in many atmospheric processes affecting both weather and climate. Airborne measurements of tropospheric water vapor profiles have been a longstanding observational need to not only the active remote sensing community but also to the meteorological, weather forecasting, and climate/radiation science communities. Microscale measurements of tropospheric water vapor are important for enhancing near term meteorological forecasting capabilities while mesoscale and synopticscale measurements can lead to an enhanced understanding of the complex coupled feedback mechanisms between water vapor, temperature, aerosols, and clouds. To realize tropospheric measurements of water vapor profiles over the microscale-synopticscale areas of meteorological interest, a compact and cost effective airborne micropulse differential absorption lidar (DIAL) is being investigated using newly emerging semiconductor based laser technology. Ground based micropulse DIAL (MPD) measurements of tropospheric water vapor and aerosol profiles up to 6 km and 15 km, respectively, have been previously demonstrated using an all semiconductor based laser transmitter. The DIAL transmitter utilizes a master oscillator power amplifier (MOPA) configuration where two semiconductor seed lasers are used to seed a single pass traveling wave tapered semiconductor optical amplifier (TSOA), producing up to 7μJ pulse energies over a 1 μs pulse duration at a 10 kHz pulse repetition frequency (PRF). Intercomparisons between the ground based instrument measurements and radiosonde profiles demonstrating the MPD performance under varying atmospheric conditions will be presented. Work is currently ongoing to expand upon the ground based MPD concept and to develop a compact and cost effective system capable of deployment on a mid-low altitude aircraft such as the NASA Langley B200 King Air. Initial lab experiments show that a two-three fold increase in the laser energy compared to the ground based instrument is achievable via overdriven current pulses to the TSOA gain medium while maintaining a 1μs and 10 kHz pulse width and PRF, respectively. The increase in the laser transmitter pulse energy will allow for nighttime and daytime water vapor profile retrievals from an airborne platform operating at an 8 km altitude with 2-5 minute integration periods. Results from a numerical model demonstrating the performance of an airborne DIAL system with the mentioned transmitter enhancements will be presented and compared against the existing ground based instrument performance. Furthermore, results from laboratory experiments demonstrating the laser transmitter performance including maximum extractable energy, energy stability, and spectral purity will also be presented.

Recent lidar technology developments and their influence on measurements of tropospheric water vapor

NASA Technical Reports Server (NTRS)

Ismail, Syed; Browell, Edward V.

1994-01-01

In this paper the influences of recent technology developments in the areas of lasers, detectors, andoptical filters of a differential absorption lidar (DIAL) system on the measurenent of tropospheric water vapor (H2O) profiles are discussed. The lidar parameters selected are based upon a diode-seeded Ti:sapphire laser that is locked to an H2O line in the 820- or 930-nm band of H2O. To assess the influence of the mode of deployment on the measurement of tropospheric H2O, DIAL performance is evaluated for operation from a medium-altitude (12 km) aircraft, the ground, and space-based systems. It is found that incorporation of these developments could greatly enhance DIAL measurement capability.

Optical Access Networks

NASA Astrophysics Data System (ADS)

Zheng, Jun; Ansari, Nirwan

2005-03-01

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to:

Gay and Bisexual men's use of the Internet: Research from the 1990s through 2013

PubMed Central

Grov, Christian; Breslow, Aaron S.; Newcomb, Michael E.; Rosenberger, Joshua G.; Bauermeister, Jose A

2014-01-01

In this review, we document the historical and cultural shifts in how gay and bisexual men have used the Internet for sexuality between the 1990s and 2013. Over that time, gay and bisexual men have rapidly taken to using the Internet for sexual purposes: sexual health information seeking, finding sex partners, dating, cybersex, and pornography. Gay and bisexual men have adapted to the ever-evolving technological advances that have been made in connecting users to the Internet—from logging into the World Wide Web via dial-up modem on a desktop computer to geo-social and sexual networking via a handheld device. In kind, researchers too have adapted to the Internet to study gay and bisexual men, though not at the same rapid pace at which technology (and its users) have advanced. Studies have carefully considered the ethics, feasibility, and acceptability of using the Internet to conduct research and interventions with gay and bisexual men. Much of this work has been grounded in models of disease prevention, largely as a result of the ongoing HIV/AIDS epidemic. The urgent need to reduce HIV in this population has been a driving force to develop innovative research and Internet-based intervention methodologies. Moving forward, a more holistic understanding of gay and bisexual men's sexual behavior might be warranted to address continued HIV and STI disparities. The Internet, and specifically mobile technology, is an environment gay and bisexual men are using for sexual purposes. These innovative technologies represent powerful resources for researchers to study and provide rapidly evolving outreach to gay and bisexual men. PMID:24754360

Results of AEROSAT channel simulation tests Q-M/PSK voice/data modem, TSC ranging modem

DOT National Transportation Integrated Search

1976-07-01

Two modems which are candidates for the Aeronautical Satellite (AEROSAT : Test and Evaluation Program have been tested by the Transportation : Systems Center channel simulation facility. One was a hybrid modem : which can simultaneously transmit and ...

Integrating stochastic time-dependent travel speed in solution methods for the dynamic dial-a-ride problem

PubMed Central

Schilde, M.; Doerner, K.F.; Hartl, R.F.

2014-01-01

In urban areas, logistic transportation operations often run into problems because travel speeds change, depending on the current traffic situation. If not accounted for, time-dependent and stochastic travel speeds frequently lead to missed time windows and thus poorer service. Especially in the case of passenger transportation, it often leads to excessive passenger ride times as well. Therefore, time-dependent and stochastic influences on travel speeds are relevant for finding feasible and reliable solutions. This study considers the effect of exploiting statistical information available about historical accidents, using stochastic solution approaches for the dynamic dial-a-ride problem (dynamic DARP). The authors propose two pairs of metaheuristic solution approaches, each consisting of a deterministic method (average time-dependent travel speeds for planning) and its corresponding stochastic version (exploiting stochastic information while planning). The results, using test instances with up to 762 requests based on a real-world road network, show that in certain conditions, exploiting stochastic information about travel speeds leads to significant improvements over deterministic approaches. PMID:25844013

Diode injection - seeded, 940 nanometer (nm), titanium - sapphire laser for H2O DIAL (differential absorption lidar), measurements

NASA Technical Reports Server (NTRS)

Miller, George E.

1992-01-01

Differential absorption of laser radiation by various molecular species represents both a selective and a sensitive method of measuring specific atmospheric constituents. DIAL measurements can be carried out via two different means. Both involve using two laser pulses with slightly different wavelengths (lambda), (one lambda at a strong absorption line of the molecule of interest, the other detuned into the wing of the line), and comparing the attenuation of the pulses. One approach relies on scattering of the radiation from some conveniently located topographical target. In the other technique elastic scattering from atmospheric aerosols and particulates is used to return the radiation to the lidar receiver system. This case is referred to as the differential absorption and scattering technique, and is the technique we are interested in to measure water vapor at 940 nm. The 940 nm wavelength is extremely desirable to atmospheric scientist interested in accurate DIAL measurements of H2O in the upper and lower troposphere. Simulated measurements using approximately 940 nm and 815 nm lasers at a range of altitudes and experimental conditions are shown. By offering access to larger absorption cross-sections, injected seeded, 940 nm DIAL laser transmitters would allow for more accurate water profile measurements at altitudes from 6 to 16 km than is currently possible with 730 nm and 815 nm DIAL laser transmitters. We have demonstrated the operation of an injected seeded titanium-sapphire (TS) laser operating at approximately 940 nm with an energy of more than 90 mJ per pulse. The TS laser is pumped by a commercial, 600 mJ, 532 nm, 10 Hz Nd:YAG laser. The slope efficiency of the laser using a flat 50 percent R output coupler and a 10 m end-mirror is shown. The laser was injected seeded with a CW, AlGaAs, semiconductor diode laser which had an output of 83 mW. The CW diode seed beam was introduced into the TS laser cavity through a HR end-mirror. When the diode beam is aligned to the TS resonator, it controls the TS laser output wavelength and its spectral line width with the required resolution for DIAL applications. This work supports the need for the development of 940 nm, titanium-sapphire DIAL transmitters.

Development and characterisation of FPGA modems using forward error correction for FSOC

NASA Astrophysics Data System (ADS)

Mudge, Kerry A.; Grant, Kenneth J.; Clare, Bradley A.; Biggs, Colin L.; Cowley, William G.; Manning, Sean; Lechner, Gottfried

2016-05-01

In this paper we report on the performance of a free-space optical communications (FSOC) modem implemented in FPGA, with data rate variable up to 60 Mbps. To combat the effects of atmospheric scintillation, a 7/8 rate low density parity check (LDPC) forward error correction is implemented along with custom bit and frame synchronisation and a variable length interleaver. We report on the systematic performance evaluation of an optical communications link employing the FPGA modems using a laboratory test-bed to simulate the effects of atmospheric turbulence. Log-normal fading is imposed onto the transmitted free-space beam using a custom LabVIEW program and an acoustic-optic modulator. The scintillation index, transmitted optical power and the scintillation bandwidth can all be independently varied allowing testing over a wide range of optical channel conditions. In particular, bit-error-ratio (BER) performance for different interleaver lengths is investigated as a function of the scintillation bandwidth. The laboratory results are compared to field measurements over 1.5km.

Molecular and isotopic composition of lipids in modern and fossil bivalve shells: Records of paleoenvironmental change?

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

CoBabe, E.A.

1995-12-31

Suites of lipids residing in situ in modern and fossil bivalve shells offer new possibilities for the study of paleoecology and paleoclimatology. Distributions of carbon isotopic compositions of modem shell lipids suggests that many of these compounds, including alkanes, sterols, fatty acids, ketones and phytadienes, are derived from the bivalves and not directly from the surrounding environment. The occurrence of fatty acids in modem and fossil shell material opens up the possibility that saturation levels of these compounds may be used as paleothermometers. To date, the utility of fatty acids in paleoclimate studies has been limited because of the swiftmore » breakdown of these compounds in sediment. However, initial results indicate that fatty acids in bivalve shells retain their original structure for at least several million years. Comparison of modem bivalve shell fatty acids from tropical, temperate and polar nearshore marine systems will be presented, along with analogous fossil data.« less

The effect of cell phone use on postural balance and mobility in older compared to young adults.

PubMed

Laatar, Rabeb; Kachouri, Hiba; Borji, Rihab; Rebai, Haithem; Sahli, Sonia

2017-05-01

Cell phone use is considered as an essential part of everyday life saturating all age groups and demographics. This study aimed to explore the effect of various cell phone functions on postural control and mobility in the elderly. Twenty healthy older (mean age 72.5±2.9) and twenty young (26.3±2.8) adults participated in this study. Postural balance was assessed by measuring the center of pressure (CoP) displacement with (talking on a cell phone (CONVERSE), dialing a number (DIAL) and listening to music (MUSIC)) and without cell phone use. Mobility was assessed by the Timed Up and Go Test (TUGT). Results showed that for both groups, the CoP parameters increased significantly during the CONVERSE (p<0.001) and the DIAL (CoP area , CoP X : p<0.05; CoP Y : p<0.01) conditions compared to the control condition. Moreover, the CoP area values were significantly higher during the CONVERSE condition in comparison to the DIAL (p<0.05) one. In older adults, the TUGT scores increased significantly in the DIAL (p<0.01) condition compared to the CONVERSE and the MUSIC conditions. In conclusion, cell phone use impairs similarly standing postural balance of elderly and young adults. Interestingly, in the elderly, all cell phone functions used altered mobility with the dialing function causing the largest mobility deterioration. Copyright © 2017 Elsevier Inc. All rights reserved.

New capability for ozone dial profiling measurements in the troposphere and lower stratosphere from aircraft

NASA Astrophysics Data System (ADS)

Hair, Johnathan; Hostetler, Chris; Cook, Anthony; Harper, David; Notari, Anthony; Fenn, Marta; Newchurch, Mike; Wang, Lihua; Kuang, Shi; Knepp, Travis; Burton, Sharon; Ferrare, Richard; Butler, Carolyn; Collins, Jim; Nehrir, Amin

2018-04-01

Recently, we successfully demonstrated a new compact and robust ozone DIAL lidar for smaller aircraft such as the NASA B200 and the ER-2 high-altitude aircraft. This is the first NASA airborne lidar to incorporate advanced solid-state lasers to produce the required power at the required ultraviolet wavelengths, and is compact and robust enough to operate nearly autonomously on the high-altitude ER-2 aircraft. This technology development resulted in the first new NASA airborne ozone DIAL instrument in more than 15 years. The combined ozone, aerosol, and clouds measurements provide valuable information on the chemistry, radiation, and dynamics of the atmosphere. In particular, from the ER-2 it offers a unique capability to study the upper troposphere and lower stratosphere.

Distributed Sensor Networks

DTIC Science & Technology

1980-09-30

the main Laboratory is provided by 9600-baud short-haul modems with unloaded lines. A new version of the real-time kernel (DAK) has been developed. It...and control computer have been in- vestigated, modems have been procured, and an initial 4-wire line with 9.6 kbits modem has been installed between the...telephone system or leased (unloaded) 4-wire private-line metallic circuits. To this end, two pairs of short-haul modems and a pair of long-haul modems have

MAGTF (Marine Air Ground Task Force) Data Transfer Alternatives (1986-1996).

DTIC Science & Technology

1986-04-01

Devices currently on the market offer circuit conditioning and access control as well as the required dial-up connectivity. A program to provide dial... UGC -74A(V)3 Communication Terminal (Teletype Writer (TTY) CV-3591 Advanced Narrowband Digital Voice Terminal (ANDVT) AN/TGC-46 TTY Central (part of AN...interface directly with both AN/ UGC -74 TTY and ADPE-FMF/EUC equipment over serial circuits. 5.5.2.2 Switching Equipment. Switching equipments perform the

Feasibility Study For A Spaceborne Ozone/Aerosol Lidar System

NASA Technical Reports Server (NTRS)

Campbell, Richard E.; Browell, Edward V.; Ismail, Syed; Dudelzak, Alexander E.; Carswell, Allan I.; Ulitsky, Arkady

1997-01-01

Because ozone provides a shield against harmful ultraviolet radiation, determines the temperature profile in the stratosphere, plays important roles in tropospheric chemistry and climate, and is a health risk near the surface, changes in natural ozone layers at different altitudes and their global impact are being intensively researched. Global ozone coverage is currently provided by passive optical and microwave satellite sensors that cannot deliver high spatial resolution measurements and have particular limitations in the troposphere. Vertical profiling DIfferential Absorption Lidars (DIAL) have shown excellent range-resolved capabilities, but these systems have been large, inefficient, and have required continuous technical attention for long term operations. Recently, successful, autonomous DIAL measurements have been performed from a high-altitude aircraft (LASE - Lidar Atmospheric Sensing Experiment), and a space-qualified aerosol lidar system (LITE - Laser In-space Technology Experiment) has performed well on Shuttle. Based on the above successes, NASA and the Canadian Space Agency are jointly studying the feasibility of developing ORACLE (Ozone Research with Advanced Cooperative Lidar Experiments), an autonomously operated, compact DIAL instrument to be placed in orbit using a Pegasus class launch vehicle.

Remote Synchronization Experiments for Future Quasi-Zenith Satellite System Using Current Geostationary Satellites

DTIC Science & Technology

2008-12-01

Timekeeping,” Application Note 1289 (Hewlett-Packard), p. 60. [5] F. Tappero, A. Dempster, T . Iwata, M. Imae, T . Ikegami , Y. Fukuyama, K. Hagimoto, and A...the timing controller are also received. Modem ( T ): The Modem ( T ) is one of the three TWSTFT modems used in the experiments (“ T ” stands for...PN signal. In the experiments, the modem ( T ) was referenced to the time signal of the TTA and the RESSOX control signal was transmitted to the modem

Experimentation and Evaluation of Advanced Integrated System Concepts.

DTIC Science & Technology

1980-09-26

ART). (b) Selects one of four trunk circuits from each trunk (m) Dual Modem and Loop Interface (DMLI) card. circuit card. (n) Dictation and paging...Arbitrator L Bus - Modems ET _Modems Modems Figure 4-1 Certain Telenet Processor models (see Section 4.3 for details) can be equipped with redundancy to...JMemory Bank B Memory Bank A ArbittrAto Arbitrator A t a i Interface U a Modems $ Figure 4-2 In a system with common logic redundancy all centrally

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

Introducing heterogeneous users and vehicles into models and algorithms for the dial-a-ride problem.

PubMed

Parragh, Sophie N

2011-08-01

Dial-a-ride problems deal with the transportation of people between pickup and delivery locations. Given the fact that people are subject to transportation, constraints related to quality of service are usually present, such as time windows and maximum user ride time limits. In many real world applications, different types of users exist. In the field of patient and disabled people transportation, up to four different transportation modes can be distinguished. In this article we consider staff seats, patient seats, stretchers and wheelchair places. Furthermore, most companies involved in the transportation of the disabled or ill dispose of different types of vehicles. We introduce both aspects into state-of-the-art formulations and branch-and-cut algorithms for the standard dial-a-ride problem. Also a recent metaheuristic method is adapted to this new problem. In addition, a further service quality related issue is analyzed: vehicle waiting time with passengers aboard. Instances with up to 40 requests are solved to optimality. High quality solutions are obtained with the heuristic method.

A new frontier in CO2 flux measurements using a highly portable DIAL laser system

PubMed Central

Queiβer, Manuel; Granieri, Domenico; Burton, Mike

2016-01-01

Volcanic CO2 emissions play a key role in the geological carbon cycle, and monitoring of volcanic CO2 fluxes helps to forecast eruptions. The quantification of CO2 fluxes is challenging due to rapid dilution of magmatic CO2 in CO2-rich ambient air and the diffuse nature of many emissions, leading to large uncertainties in the global magmatic CO2 flux inventory. Here, we report measurements using a new DIAL laser remote sensing system for volcanic CO2 (CO2DIAL). Two sites in the volcanic zone of Campi Flegrei (Italy) were scanned, yielding CO2 path-amount profiles used to compute fluxes. Our results reveal a relatively high CO2 flux from Campi Flegrei, consistent with an increasing trend. Unlike previous methods, the CO2DIAL is able to measure integrated CO2 path-amounts at distances up to 2000 m using virtually any solid surface as a reflector, whilst also being highly portable. This opens a new frontier in quantification of geological and anthropogenic CO2 fluxes. PMID:27652775

Search Hardware: Latest and Greatest.

ERIC Educational Resources Information Center

Alberico, Ralph

1988-01-01

Uses the different search environments of information brokers and institutional searchers to illustrate the factors that should be considered when selecting microcomputers for search operations. The factors discussed include speed, storage capabilities, displays, modems, printing technologies, facsimile transmission, and portability. A directory…

A Ground-Based 2-Micron DIAL System to Profile Tropospheric CO2 and Aerosol Distributions for Atmospheric Studies

NASA Technical Reports Server (NTRS)

Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Davis, Kenneth; Miller, Charles; Singh, Upendra

2006-01-01

System will operate at a temperature insensitive CO2 line (2050.967 nm) with side-line tuning and off-set locking. Demonstrated an order of magnitude improvement in laser line locking needed for high precision measurements, side-line operation, and simultaneously double pulsing and line locking. Detector testing of phototransistor has demonstrated sensitivity to aerosol features over long distances in the atmosphere and resolve features approx. 100m. Optical systems that collect light onto small area detectors work well. Receiver optical designs are being optimized and data acquisition systems developed. CO2 line parameter characterization in progress In situ sensor calibration in progress for validation of DIAL CO2 system.

Investigation of potential of differential absorption Lidar techniques for remote sensing of atmospheric pollutants

NASA Technical Reports Server (NTRS)

Butler, C. F.; Shipley, S. T.; Allen, R. J.

1981-01-01

The NASA multipurpose differential absorption lidar (DIAL) system uses two high conversion efficiency dye lasers which are optically pumped by two frequency-doubled Nd:YAG lasers mounted rigidly on a supporting structure that also contains the transmitter, receiver, and data system. The DIAL system hardware design and data acquisition system are described. Timing diagrams, logic diagrams, and schematics, and the theory of operation of the control electronics are presented. Success in obtaining remote measurements of ozone profiles with an airborne systems is reported and results are analyzed.

A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

NASA Astrophysics Data System (ADS)

Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

2014-12-01

High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to <57Kbps. Free-water optical modems (OMs) offer high data rate, 10Mbps communications over a range of 200 m - a distance for ROVs, AUVs or wire-lowered packages to communicate without the need to directly plug-in or retrieve the instrument. Over the past 4 years, we have demonstrated the functionality and utility of OM technology using a CORK borehole observatory as a test case. A CORK represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor and a standard communication interface. The CORK-OM features a high-bandwidth, low-latency optical system based on LED emitters and PMT receivers and an acoustic command and control system. OM tests established a communication link from 20 to 200 meters range at rates of 1, 5 and 10 Mbps with no bit errors. The seafloor OM was plugged into the CORK's existing underwater wet mateable connector and provided additional power to the CORK to boost the data rate to 1 Hz from the normal 1 minute sample period. To communicate with the seafloor CORK-OM, a number of different modalities were used. One method was an OM mounted to a CTD frame on a lowered wire from a ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next generation OM using a deployed seafloor modem and AUV Sentry. A complete lambertian optical field was quantitatively mapped by Sentry and test data was successfully downloaded from 20 to 150 m slant range. The AUV modality demonstrates the capability of 'data-mule' operations to autonomously recover data from a seafloor observatory with minimal human intervention.

Analog Building Blocks for Communications Modems.

DTIC Science & Technology

1977-01-01

x*—*- A0-A039 82b ELECTRONIC COMMUNICATIONS INC ST PETERSBURG FLA F/6 9/5 ANALOG BUILDING BLOCKS FOR COMMUNICATIONS MODEMS .(U) JAN 77 B BLACK...F33615-7<t-C-1120 UNCLASSIFIED AFAL-TR-76-29 NL ANALOG BUILDING BLOCKS FOR COMMUNICATIONS MODEMS ELECTRONIC COMMUNICATIONS INC. A SUBSIDIARY OF...Idantltr Or Mac* numb*,; Avionics Building-Block modules Frequency Synthesize* Costas Demodulator Amplifier Modem Frequency Multiplier ’ -^ « TRACT

System Design Plan for a DCS (Defense Communications System) Data Transmission Network.

DTIC Science & Technology

1981-07-01

modems , FDO group modems , and Voice Frequency Carrier Telegraph (VFCT) networks. The DTN will be a synchronous network and its implementation must coincide...Frequency (VF) modems and Voice Frequency Carrier Telegraph (VFCT) networks. Further, data circuits can be extended over present analog FDM facilities using...VF or group data modems . In addition to the availability of terrestrial and satellite digital transmission facilities, the implementation of the DTN

Efficient 1.6 Micron Laser Source for Methane DIAL

NASA Technical Reports Server (NTRS)

Shuman, Timothy; Burnham, Ralph; Nehrir, Amin R.; Ismail, Syed; Hair, Johnathan W.

2013-01-01

Methane is a potent greenhouse gas and on a per molecule basis has a warming influence 72 times that of carbon dioxide over a 20 year horizon. Therefore, it is important to look at near term radiative effects due to methane to develop mitigation strategies to counteract global warming trends via ground and airborne based measurements systems. These systems require the development of a time-resolved DIAL capability using a narrow-line laser source allowing observation of atmospheric methane on local, regional and global scales. In this work, a demonstrated and efficient nonlinear conversion scheme meeting the performance requirements of a deployable methane DIAL system is presented. By combining a single frequency 1064 nm pump source and a seeded KTP OPO more than 5 mJ of 1.6 µm pulse energy is generated with conversion efficiencies in excess of 20%. Even without active cavity control instrument limited linewidths (50 pm) were achieved with an estimated spectral purity of 95%. Tunable operation over 400 pm (limited by the tuning range of the seed laser) was also demonstrated. This source demonstrated the critical needs for a methane DIAL system motivating additional development of the technology.

Terminal area automatic navigation, guidance and control research using the Microwave Landing System (MLS). Part 5: Design and development of a Digital Integrated Automatic Landing System (DIALS) for steep final approach using modern control techniques

NASA Technical Reports Server (NTRS)

Halyo, N.

1983-01-01

The design and development of a 3-D Digital Integrated Automatic Landing System (DIALS) for the Terminal Configured Vehicle (TCV) Research Aircraft, a B-737-100 is described. The system was designed using sampled data Linear Quadratic Gaussian (LOG) methods, resulting in a direct digital design with a modern control structure which consists of a Kalman filter followed by a control gain matrix, all operating at 10 Hz. DIALS uses Microwave Landing System (MLS) position, body-mounted accelerometers, as well as on-board sensors usually available on commercial aircraft, but does not use inertial platforms. The phases of the final approach considered are the localizer and glideslope capture which may be performed simultaneously, localizer and steep glideslope track or hold, crab/decrab and flare to touchdown. DIALS captures, tracks and flares from steep glideslopes ranging from 2.5 deg to 5.5 deg, selected prior to glideslope capture. Digital Integrated Automatic Landing System is the first modern control design automatic landing system successfully flight tested. The results of an initial nonlinear simulation are presented here.

The Use of a Microcomputer as an EKG Monitor.

ERIC Educational Resources Information Center

Walters, R. A.; Reynolds, R. F.

1983-01-01

Discusses the design and operation of a microcomputer system which obtains and displays an individual's electrocardiogram (EKG). The EKG information, in digital form, can be stored on a floppy disk and transmitted over telephone lines by use of a modem. (JN)

Exacerbation of demyelinating syndrome after exposure to wireless modem with public hotspot.

PubMed

Johansson, Olle; Redmayne, Mary

2016-01-01

In August 2003, 48-year-old JS of Colorado, USA, a fitness therapist and sports nutritionist, contracted neuroinvasive West Nile virus which left her with disabilities due to spinal axonal damage.In August 2014, she suddenly developed symptoms very much like her acute West Nile infection 11 years ago, including focal seizures, ataxia, vertigo and headaches. Her blood count looked normal so there was no obvious infection. What struck her as odd was that when she left her apartment for any length of time, the symptoms stopped. She found out that a new type of wireless modem, enabled for both personal use and functioning as a public hotspot designed to reach up to 100 m, had been installed in the flat under hers.Her neighbor replaced the modem with a router without the hotspot feature. After that, the seizures stopped immediately, and the other symptoms faded gradually, after which she was fine and again could sleep well. Later, when another activated hotspot was installed in an adjacent flat, JS once again noticed symptoms.A possible association between electrohypersensitivity, myelin integrity and exposure to low-intensity radiofrequency electromagnetic fields (RF-EMF) typical in the modern world has recently been proposed. Since the West Nile virus attacks both the nerve cells and the glial ones, one explanation to the above observed case effects is that the initial virus attack and the wireless modem's RF-EMF affect the nervous system through the very same, or similar, avenues, and maybe both via the oligodendrocytes.

Performance of Trellis Coded 256 QAM super-multicarrier modem VLSI's for SDH interface outage-free digital microwave radio

NASA Astrophysics Data System (ADS)

Aikawa, Satoru; Nakamura, Yasuhisa; Takanashi, Hitoshi

1994-02-01

This paper describes the performance of an outage free SXH (Synchronous Digital Hierarchy) interface 256 QAM modem. An outage free DMR (Digital Microwave Radio) is achieved by a high coding gain trellis coded SPORT QAM and Super Multicarrier modem. A new frame format and its associated circuits connect the outage free modem to the SDH interface. The newly designed VLSI's are key devices for developing the modem. As an overall modem performance, BER (bit error rate) characteristics and equipment signatures are presented. A coding gain of 4.7 dB (at a BER of 10(exp -4)) is obtained using SPORT 256 QAM and Viterbi decoding. This coding gain is realized by trellis coding as well as by increasing of transmission rate. Roll-off factor is decreased to maintain the same frequency occupation and modulation level as ordinary SDH 256 QAM modern.

Development and Evaluation of a High Sensitivity DIAL System for Profiling Atmospheric CO2

NASA Technical Reports Server (NTRS)

Ismail, Syed; Koch, Grady J.; Refaat, Tamer F.; Abedin, M. N.; Yu, Jirong; Singh, Upendra N.

2008-01-01

A ground-based 2-micron Differential Absorption Lidar (DIAL) CO2 profiling system for atmospheric boundary layer studies and validation of space-based CO2 sensors is being developed and tested at NASA Langley Research Center as part of the NASA Instrument Incubator Program. To capture the variability of CO2 in the lower troposphere a precision of 1-2 ppm of CO2 (less than 0.5%) with 0.5 to 1 km vertical resolution from near surface to free troposphere (4-5 km) is one of the goals of this program. In addition, a 1% (3 ppm) absolute accuracy with a 1 km resolution over 0.5 km to free troposphere (4-5 km) is also a goal of the program. This DIAL system leverages 2-micron laser technology developed under NASA's Laser Risk Reduction Program (LRRP) and other NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements. This presentation describes the capabilities of this system for atmospheric CO2 and aerosol profiling. Examples of atmospheric measurements in the lidar and DIAL mode will be presented.

Using perceptual rules in interactive visualization

NASA Astrophysics Data System (ADS)

Rogowitz, Bernice E.; Treinish, Lloyd A.

1994-05-01

In visualization, data are represented as variations in grayscale, hue, shape, and texture. They can be mapped to lines, surfaces, and glyphs, and can be represented statically or in animation. In modem visualization systems, the choices for representing data seem unlimited. This is both a blessing and a curse, however, since the visual impression created by the visualization depends critically on which dimensions are selected for representing the data (Bertin, 1967; Tufte, 1983; Cleveland, 1991). In modem visualization systems, the user can interactively select many different mapping and representation operations, and can interactively select processing operations (e.g., applying a color map), realization operations (e.g., generating geometric structures such as contours or streamlines), and rendering operations (e.g., shading or ray-tracing). The user can, for example, map data to a color map, then apply contour lines, then shift the viewing angle, then change the color map again, etc. In many systems, the user can vary the choices for each operation, selecting, for example, particular color maps, contour characteristics, and shading techniques. The hope is that this process will eventually converge on a visual representation which expresses the structure of the data and effectively communicates its message in a way that meets the user's goals. Sometimes, however, it results in visual representations which are confusing, misleading, and garish.

Flexible digital modulation and coding synthesis for satellite communications

NASA Technical Reports Server (NTRS)

Vanderaar, Mark; Budinger, James; Hoerig, Craig; Tague, John

1991-01-01

An architecture and a hardware prototype of a flexible trellis modem/codec (FTMC) transmitter are presented. The theory of operation is built upon a pragmatic approach to trellis-coded modulation that emphasizes power and spectral efficiency. The system incorporates programmable modulation formats, variations of trellis-coding, digital baseband pulse-shaping, and digital channel precompensation. The modulation formats examined include (uncoded and coded) binary phase shift keying (BPSK), quatenary phase shift keying (QPSK), octal phase shift keying (8PSK), 16-ary quadrature amplitude modulation (16-QAM), and quadrature quadrature phase shift keying (Q squared PSK) at programmable rates up to 20 megabits per second (Mbps). The FTMC is part of the developing test bed to quantify modulation and coding concepts.

Analysis of Government Facsimile Equipment and Networks

DTIC Science & Technology

1991-05-01

between a STANAG compliant Crt equipment and a Group 3 compliant equipment. Both the modems and the protocols are different. The one-dimensional portion...because Group 3 is neither purely digital nor purely analog. Group 3 uses both: on the PSTN an analog modem provides the carrier for the digital...messages. To use a Group 3 equipment on a digital link at least two approaches can be taken: first, the modem can be bypassed, or second, a second modem

Performance Results of Some Candidate French Modems for the Aeronautical Satellite Communication Channel

DOT National Transportation Integrated Search

1978-05-01

Five candidate data, voice, and ranging modems were evaluated by the AEROSAT channel simulation facility to determine applicability for use in the aeronautical satellite communication channel for air traffic control. The modems were supplied by Telec...

[Remote access to a web-based image distribution system].

PubMed

Bergh, B; Schlaefke, A; Frankenbach, R; Vogl, T J

2004-06-01

To assess different network and security technologies for remote access to a web-based image distribution system of a hospital intranet. Following preparatory testing, the time-to-display (TTD) was measured for three image types (CR, CT, MR). The evaluation included two remote access technologies consisting of direct ISDN-Dial-Up or VPN connection (Virtual Private Network), with three different connection speeds of 64, 128 (ISDN) and 768 Kbit/s (ADSL-Asymmetric Digital Subscriber Line), as well as with lossless and lossy compression. Depending on the image type, the TTD with lossless compression for 64 Kbit/s varied from 1 : 00 to 2 : 40 minutes, for 128 Kbit/s from 0 : 35 to 1 : 15 minutes and for ADSL from 0 : 15 to 0 : 45 minutes. The ISDN-Dial-Up connection was superior to VPN technology at 64 Kbit/s but did not allow higher connection speeds. Lossy compression reduced the TTD by half for all measurements. VPN technology is preferable to direct Dial-Up connections since it offers higher connection speeds and advantages in usage and security. For occasional usage, 128 Kbit/s (ISDN) can be considered sufficient, especially in conjunction with lossy compression. ADSL should be chosen when a more frequent usage is anticipated, whereby lossy compression may be omitted. Due to higher bandwidths and improved usability, the web-based approach appears superior to conventional teleradiology systems.

Quality in the Operational Air Force: A Case of Misplaced Emphasis

DTIC Science & Technology

1994-05-01

other quality advocates of the era. These men included Joseph Juran, Armand Feigenbaum, Kaoru Ishikawa , and Genichi Taguchi. Juran contributed disciplined...planning theories, while Feigenbaum felt that producing quality could actually reduce production costs. In addition, Ishikawa and Taguchi lent...statistically based problem solving techniques, but the more modem approaches of Ishikawa , Taguchi and others. The operative concept of TQM is ’continuous

Development of an Eye-Safe Micro-Pulse Differential Absorption Lidar (DIAL) for Carbon Dioxide Profilings

NASA Astrophysics Data System (ADS)

Johnson, W.; Repasky, K. S.; Nehrir, A. R.; Carlsten, J.

2011-12-01

A differential absorption lidar (DIAL) for monitoring carbon dioxide (CO2) is under development at Montana State University using commercially available parts. Two distributed feedback (DFB) lasers, one at the on-line wavelength and one at the off-line wavelength are used to injection seed a fiber amplifier. The DIAL operates in the 1.57 micron carbon dioxide absorption band at an on-line wavelength of 1.5714060 microns. The laser transmitter produces 40 μJ pulses with a pulse duration of 1 μs and a pulse repetition frequency of 20 kHz. The scattered light from the laser transmitter is collected using a 28 cm diameter Schmidt-Cassegrain telescope. The light collected by the telescope is collimated and then filtered using a 0.8 nm FWHM narrowband interference filter. After the optical filter, the light is coupled into a multimode optical fiber with a 1000 μm core diameter. The output from the optical fiber is coupled into a photomultiplier tube (PMT) used to monitor the return signal. The analog output from the PMT is next incident on a discriminator producing TTL logic pulses for photon counting. The output from the PMT and discriminator is monitored using a multichannel scalar card allowing the counting of the TTL pulses as a function of range. Data from the DIAL instrument is collected in the following manner. The fiber amplifier is injection seeded first with the on-line DFB laser. The return signal as a function of range is integrated using the multichannel scalar for a user defined time, typically set at 6 s. The off-line DFB laser is then used to injection seed the fiber amplifier and the process is repeated. This process is repeated for a user defined period. The CO2 concentration as a function of range is calculated using the on-line and off-line return signals with the DIAL equation. A comparison of the CO2 concentration measured using the DIAL instrument at 1.5 km and a Li-Cor LI-820 in situ sensor located at 1.5 km from the DIAL over a 2.5 hour period indicate that the CO2 DIAL has an accuracy of ±20 parts per million (PPM).

Digital tracking loops for a programmable digital modem

NASA Technical Reports Server (NTRS)

Poklemba, John J.

1992-01-01

In this paper, an analysis and hardware emulation of the tracking loops for a very flexible programmable digital modem (PDM) will be presented. The modem is capable of being programmed for 2, 4, 8, 16-PSK, 16-QAM, MSK, and Offset-QPSK modulation schemes over a range of data rates from 2.34 to 300 Mbps with programmable spectral occupancy from 1.2 to 1.8 times the symbol rate; these operational parameters are executable in burst or continuous mode. All of the critical processing in both the modulator and demodulator is done at baseband with very high-speed digital hardware and memory. Quadrature analog front-ends are used for translation between baseband and the IF center frequency. The modulator is based on a table lookup approach, where precomputed samples are stored in memory and clocked out according to the incoming data pattern. The sample values are predistorted to counteract the effects of the other filtering functions in the link as well as any transmission impairments. The demodulator architecture was adapted from a joint estimator-detector (JED) mathematical analysis. Its structure is applicable to most signalling formats that can be represented in a two-dimensional space. The JED realization uses interdependent, mutually aiding tracking loops with post-detection data feedback. To expedite and provide for more reliable synchronization, initial estimates for these loops are computed in a parallel acquisition processor. The cornerstone of the demodulator realization is the pre-averager received data filter which allows operation over a broad range of data rates without any hardware changes and greatly simplifies the implementation complexity. The emulation results confirmed tracking loop operation over the entire range of operational parameters listed above, as well as the capability of achieving and maintaining synchronization at BER's in excess of 10(exp -1). The emulation results also showed very close agreement with the tracking loop analysis, and validated the resolution apportionment of the various hardware elements in the tracking loops.

Development of a System to Validate Group 3 Facsimile Equipment. Phase I.

DTIC Science & Technology

1981-07-01

such as modem , equalizer, line connection etc.) in hardware is. unavoidable. 3. Unless computer and test equipment are co-resident, hardware will be...network simulator. Most of this hardware/firmware has been developed for data transmission in general (v.27 ter/V.29 modems )or specifically for Group 3...system with the facsimile unit under test. 2. V.27 ter/V.29 modems - to handle facsimile data at the various data rate. 3. Modem control and switching

Metaheuristics for the dynamic stochastic dial-a-ride problem with expected return transports.

PubMed

Schilde, M; Doerner, K F; Hartl, R F

2011-12-01

The problem of transporting patients or elderly people has been widely studied in literature and is usually modeled as a dial-a-ride problem (DARP). In this paper we analyze the corresponding problem arising in the daily operation of the Austrian Red Cross. This nongovernmental organization is the largest organization performing patient transportation in Austria. The aim is to design vehicle routes to serve partially dynamic transportation requests using a fixed vehicle fleet. Each request requires transportation from a patient's home location to a hospital (outbound request) or back home from the hospital (inbound request). Some of these requests are known in advance. Some requests are dynamic in the sense that they appear during the day without any prior information. Finally, some inbound requests are stochastic. More precisely, with a certain probability each outbound request causes a corresponding inbound request on the same day. Some stochastic information about these return transports is available from historical data. The purpose of this study is to investigate, whether using this information in designing the routes has a significant positive effect on the solution quality. The problem is modeled as a dynamic stochastic dial-a-ride problem with expected return transports. We propose four different modifications of metaheuristic solution approaches for this problem. In detail, we test dynamic versions of variable neighborhood search (VNS) and stochastic VNS (S-VNS) as well as modified versions of the multiple plan approach (MPA) and the multiple scenario approach (MSA). Tests are performed using 12 sets of test instances based on a real road network. Various demand scenarios are generated based on the available real data. Results show that using the stochastic information on return transports leads to average improvements of around 15%. Moreover, improvements of up to 41% can be achieved for some test instances.

Peak Satellite-to-Earth Data Rates Derived From Measurements of a 20 Gbps Bread-Board Modem

NASA Technical Reports Server (NTRS)

Landon, David G.; Simons, Rainee N.; Wintucky, Edwin G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen A.; McIntire, William K.; Metz, John L.; Smith, Francis J.

2011-01-01

A prototype data link using a Ka-band space qualified, high efficiency 200 W TWT amplifier and a bread-board modem emulator were created to explore the feasibility of very high speed communications in satellite-to-earth applications. Experiments were conducted using a DVB-S2-like waveform with modifications to support up to 20 Gbps through the addition of 128-Quadrature Amplitude Modulation (QAM). Limited by the bandwidth of the amplifier, a constant peak symbol rate of 3.2 Giga-symbols/sec was selected and the modulation order was varied to explore what peak data rate might be supported by an RF link through this amplifier. Using 128-QAM, an implementation loss of 3 dB was observed at 20 Gbps, and the loss decreased as data rate or bandwidth were reduced. Building on this measured data, realistic link budget calculations were completed. Low-Earth orbit (LEO) missions based on this TWTA with reasonable hardware assumptions and antenna sizing are found to be bandwidth-limited, rather than power-limited, making the spectral efficiency of 9/10-rate encoded 128-QAM very attractive. Assuming a bandwidth allocation of 1 GHz, these computations indicate that low-Earth orbit vehicles could achieve data rates up to 5 Gbps-an order of magnitude beyond the current state-of-practice, yet still within the processing power of a current FPGA-based software-defined modem. The measured performance results and a description of the experimental setup are presented to support these conclusions.

Gage monitors quality of cross-wire resistance welds

NASA Technical Reports Server (NTRS)

Etzel, J.; Piltch, A.

1968-01-01

Gage nondestructively monitors the quality of cross-wire resistance welds during the welding operation. The gage gives a dial indication of the relative embedment of the cross wires during the actual welding operation. A direct relationship exists between the depth of embedment and both weld strength and consistency.

Privately-Contracted Transportation Services for the Elderly and Handicapped in San Diego, California

DOT National Transportation Integrated Search

1985-01-01

The City of San Diego, which operated its own dial-a-ride service from 1975 to 1982, transferred all operations to the private sector in the fall of 1982, and introduced a user-side subsidy mechanism for most of its users. Since October 1984, all ser...

Optical Access Networks

NASA Astrophysics Data System (ADS)

Zheng, Jun; Ansari, Nirwan

2005-06-01

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Optical Access Networks

NASA Astrophysics Data System (ADS)

Zheng, Jun; Ansari, Nirwan; Jersey Inst Ansari, New; Jersey Inst, New

2005-04-01

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Optical Access Networks

NASA Astrophysics Data System (ADS)

Zheng, Jun; Ansari, Nirwan

2005-05-01

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or are now underway this hot area. The purpose of this feature issue is to expose the networking community to the latest research breakthroughs and progresses in the area of optical access networks. This feature issue aims to present a collection of papers that focus on the state-of-the-art research in various networking aspects of optical access networks. Original papers are solicited from all researchers involved in area of optical access networks. Topics of interest include but not limited to: Optical access network architectures and protocols Passive optical networks (BPON, EPON, GPON, etc.) Active optical networks Multiple access control Multiservices and QoS provisioning Network survivability Field trials and standards Performance modeling and analysis

Differential Absorption Lidar Measurements of Fugitive Benzene Emissions

NASA Astrophysics Data System (ADS)

Robinson, R. A.; Innocenti, F.; Helmore, J.; Gardiner, T.; Finlayson, A.; Connor, A.

2016-12-01

The Differential Absorption Lidar (DIAL) technique is based on the optical analogue of radar; lidar (light detection and ranging). It provides the capability to remotely measure the concentration and spatial distribution of compounds in the atmosphere. The ability to scan the optical measurement beam throughout the atmosphere enables pollutant concentrations to be mapped, and emission fluxes to be determined when combined with wind data. The NPL DIAL systems can operate in the UV and infrared spectral, enabling the measurement of a range of air pollutants and GHGs including hazardous air pollutants such as benzene. The mobile ground based DIAL systems developed at NPL for pollution monitoring have been used for over 25 years. They have been deployed for routine monitoring, emission factor studies, research investigations and targeted monitoring campaigns. More recently the NPL DIAL has been used in studies to validate other monitoring techniques. In support of this capability, NPL have developed a portable, configurable controlled release system (CRF) able to simulate emissions from typical sources. This has been developed to enable the validation and assessment of fugitive emission monitoring techniques. Following a brief summary of the technique, we outline recent developments in the use of DIAL for monitoring fugitive and diffuse emissions, including the development of a European Standard Method for fugitive emission monitoring. We will present the results of a number of validation exercises using the CRF presenting an update on the performance of DIAL for emission quantification and discuss the wider validation of novel technologies. We will report on recent measurements of the emissions of benzene from industrial sites including a large scale emissions monitoring study carried out by the South Coast Air Quality Management District (SCAQMD) and will report on the measurement of emissions from petrochemical facilities and examine an example of the identification and quantification of a significant benzene release from a facility in Europe. We will discuss the use of advanced techniques such as DIAL in support of the recently introduced EPA refinery rule (and the long term sampling approach in EPA method 325) and explore the role these techniques can have in providing improved data on emissions.

Knowledge-based operation and management of communications systems

NASA Technical Reports Server (NTRS)

Heggestad, Harold M.

1988-01-01

Expert systems techniques are being applied in operation and control of the Defense Communications System (DCS), which has the mission of providing reliable worldwide voice, data and message services for U.S. forces and commands. Thousands of personnel operate DCS facilities, and many of their functions match the classical expert system scenario: complex, skill-intensive environments with a full spectrum of problems in training and retention, cost containment, modernization, and so on. Two of these functions are: (1) fault isolation and restoral of dedicated circuits at Tech Control Centers, and (2) network management for the Defense Switched Network (the modernized dial-up voice system currently replacing AUTOVON). An expert system for the first of these is deployed for evaluation purposes at Andrews Air Force Base, and plans are being made for procurement of operational systems. In the second area, knowledge obtained with a sophisticated simulator is being embedded in an expert system. The background, design and status of both projects are described.

Knowledge-based operation and management of communications systems

NASA Astrophysics Data System (ADS)

Heggestad, Harold M.

1988-11-01

Expert systems techniques are being applied in operation and control of the Defense Communications System (DCS), which has the mission of providing reliable worldwide voice, data and message services for U.S. forces and commands. Thousands of personnel operate DCS facilities, and many of their functions match the classical expert system scenario: complex, skill-intensive environments with a full spectrum of problems in training and retention, cost containment, modernization, and so on. Two of these functions are: (1) fault isolation and restoral of dedicated circuits at Tech Control Centers, and (2) network management for the Defense Switched Network (the modernized dial-up voice system currently replacing AUTOVON). An expert system for the first of these is deployed for evaluation purposes at Andrews Air Force Base, and plans are being made for procurement of operational systems. In the second area, knowledge obtained with a sophisticated simulator is being embedded in an expert system. The background, design and status of both projects are described.

Impact of Satellite Aeronautical Channel on Modem Specifications : Phase II. Oceanic Multipath Measurements and Modem Concepts

DOT National Transportation Integrated Search

1975-01-01

The report completes the analysis initiated in the Phase I report of the effects of oceanic multipath on ranging and data modems for satellite air traffic control systems. The interaction between multipath antenna and apparent measured multipath is d...

Impact of Satellite Aeronautical Channel on Modem Specifications : Phase II. Oceanic Multipath Measurements and Modem Concepts

DOT National Transportation Integrated Search

1975-01-01

This report completes the analysis inititaed in the Phase I report of the effects of oceanic multipath on ranging and data modems for satellite air traffic control systems. The interaction between multipath antenna and apparent measured multipath is ...

Mobile Phone Terminal

NASA Technical Reports Server (NTRS)

1978-01-01

In the photo, an employee of a real estate firm is contacting his office by means of HICOM, an advanced central terminal for mobile telephones. Developed by the Orlando Division of Martin Marietta Aerospace, Orlando, Florida, and manufactured by Harris Corporation's RF Division, Rochester, N.Y., HICOM upgrades service to users, provides better system management to telephone companies, and makes more efficient use of available mobile telephone channels through a computerized central control terminal. The real estate man, for example, was able to dial his office and he could also have direct-dialed a long distance number. Mobile phones in most areas not yet served by HICOM require an operator's assistance for both local and long distance calls. HICOM improves system management by automatically recording information on all calls for accurate billing, running continual performance checks on its own operation, and reporting any malfunctions to a central office.

Development of a PLC modem for data transmission over a PWM power supply

NASA Astrophysics Data System (ADS)

Batard, Christophe; Ginot, Nicolas; Mannah, Marc Anthony; Millet, Christophe; Poitiers, Frédéric

2014-04-01

In variable-speed electrical drive and online conditioning monitoring, a feedback loop is required in order to transmit the sensor information from the motor to the controller close to the inverter. Additional cabling is used for signalling. This extra cabling has a significant cost and data transmission may not be reliable. Thus, the use of power line communication (PLC) technology to transmit data in motor drive application is quite interesting. The use of a PLC modem dedicated to the home network in a three-phase inverter-fed motor power cable does not work. Therefore, specific coupling interfaces are developed to transmit data through a pulse-width modulated power supply. Laboratory tests have shown that the couplers are operating properly. They ensure reliable data transmission in a motor drive application.

Autonomous Mobile Platform for Research in Cooperative Robotics

NASA Technical Reports Server (NTRS)

Daemi, Ali; Pena, Edward; Ferguson, Paul

1998-01-01

This paper describes the design and development of a platform for research in cooperative mobile robotics. The structure and mechanics of the vehicles are based on R/C cars. The vehicle is rendered mobile by a DC motor and servo motor. The perception of the robot's environment is achieved using IR sensors and a central vision system. A laptop computer processes images from a CCD camera located above the testing area to determine the position of objects in sight. This information is sent to each robot via RF modem. Each robot is operated by a Motorola 68HC11E micro-controller, and all actions of the robots are realized through the connections of IR sensors, modem, and motors. The intelligent behavior of each robot is based on a hierarchical fuzzy-rule based approach.

Performance of convolutionally encoded noncoherent MFSK modem in fading channels

NASA Technical Reports Server (NTRS)

Modestino, J. W.; Mui, S. Y.

1976-01-01

The performance of a convolutionally encoded noncoherent multiple-frequency shift-keyed (MFSK) modem utilizing Viterbi maximum-likelihood decoding and operating on a fading channel is described. Both the lognormal and classical Rician fading channels are considered for both slow and time-varying channel conditions. Primary interest is in the resulting bit error rate as a function of the ratio between the energy per transmitted information bit and noise spectral density, parameterized by both the fading channel and code parameters. Fairly general upper bounds on bit error probability are provided and compared with simulation results in the two extremes of zero and infinite channel memory. The efficacy of simple block interleaving in combatting channel memory effects are thoroughly explored. Both quantized and unquantized receiver outputs are considered.

The NASA Langley High Altitude Lidar Observatory (HALO) - Advancements in Airborne DIAL Measurements of CH4 and H2O

NASA Astrophysics Data System (ADS)

Nehrir, A. R.; Hair, J. W.; Ferrare, R. A.; Hostetler, C. A.; Notari, A.; Collins, J. E., Jr.; Hare, R. J.; Harper, D. B.; Antill, C.; Cook, A. L.; Young, J.; Chuang, T.; Welch, W.

2016-12-01

Atmospheric methane (CH4) has the second largest radiative forcing of the long-lived greenhouse gasses (GHG) after carbon dioxide. However, methane's much shorter atmospheric lifetime and much stronger warming potential make its radiative forcing equivalent to that for CO2 over a 20-year time horizon which makes CH4 a particularly attractive target for mitigation strategies. Similar to CH4, water vapor (H2O) is the most dominant of the short-lived GHG in the atmosphere and plays a key role in many atmospheric processes. Atmospheric H2O concentrations span over four orders of magnitude from the planetary boundary layer where high impact weather initiates to lower levels in the upper troposphere and lower stratosphere where water vapor has significant and long term impacts on the Earth's radiation budget. Active remote sensing employing the differential absorption lidar (DIAL) technique enables scientific assessments of both natural and anthropogenic sources and sinks of CH4 with high accuracy and precision as well as and its impacts on the climate. The DIAL technique also allows for profiling of tropospheric water vapor for weather and climate applications with unprecedented spatial and temporal resolution. NASA Langley is developing the High Altitude Lidar Observatory (HALO) lidar system to address the observational needs of NASA's weather, climate, carbon cycle, and atmospheric composition focus areas. HALO is a multi-function airborne lidar being developed to measure atmospheric H2O and CH4 mixing ratios and aerosol and cloud optical properties using the DIAL and High Spectral Resolution Lidar (HSRL) techniques, respectively. HALO is designed as an airborne simulator for future space based DIAL missions and will serve as test bed for risk reduction of key technologies required of future space based GHG DIAL missions. A system level overview and up-to-date progress of the HALO lidar will be presented. Simulations on the expected accuracy and precision of HALO CH4 and H2O DIAL measurements will also be presented.

COSMOS (County of San Mateo Online System). A Searcher's Manual.

ERIC Educational Resources Information Center

San Mateo County Superintendent of Schools, Redwood City, CA. Educational Resources Center.

Operating procedures are explained for COSMOS (County of San Mateo Online System), a computerized information retrieval system designed for the San Mateo Educational Resources Center (SMERC), which provides interactive access to both ERIC and a local file of fugitive documents. COSMOS hardware and modem compatibility requirements are reviewed,…

The Electronic Classroom.

ERIC Educational Resources Information Center

Mizell, Al P.; Centini, Barry M.

The role of telecommunications in establishing the electronic classroom in distance education is illustrated. Using a computer-based doctoral program and the UNIX operating system as an example, how a personal computer and modem may be combined with a telephone line for instructional delivery is described. A number of issues must be addressed in…

Gyro and Accelerometer Based Navigation System for a Mobile Autonomous Robot.

DTIC Science & Technology

1985-12-02

special thanks goes to our thesis advisor Dr. Matthew Kabrisky for having the confidence to turn us loose on this project. Additionally, we would...Wordmaster Word Processor 1 Wordstar Word Processor 1 Virtual Devices Robo A 6802 Cross Assembler 1 Modem 720 Communication Program 1 CP/M Operating

Recommended Practice for Securing Control System Modems

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

James R. Davidson; Jason L. Wright

2008-01-01

This paper addresses an often overlooked “backdoor” into critical infrastructure control systems created by modem connections. A modem’s connection to the public telephone system is similar to a corporate network connection to the Internet. By tracing typical attack paths into the system, this paper provides the reader with an analysis of the problem and then guides the reader through methods to evaluate existing modem security. Following the analysis, a series of methods for securing modems is provided. These methods are correlated to well-known networking security methods.

Advanced On-the-Job Training System: Transition Plan

DTIC Science & Technology

1990-05-01

992NP. The 992NP is connected to the UDS CSU/DSU 56K modem with standard telephone wire (four wire). The 56K modem is connected to the 56K communications...UDS CSU/DSU 56K modems . One 56K line from Brooks is connected to Building 428 and the other line is connected to Building 1101. Building 1101 acts as...the central communications node at Bergstrom AFB as illustrated in Figure A- 4. The 56K lines from Brooks are connected to the 56K modems which are in

Two way time transfer results at NRL and USNO

NASA Technical Reports Server (NTRS)

Galysh, Ivan J.; Landis, G. Paul

1993-01-01

The Naval Research Laboratory (NRL) has developed a two way time transfer modem system for the United States Naval Observatory (USNO). Two modems in conjunction with a pair of Very Small Aperture Terminal (VSAT) and a communication satellite can achieve sub nanosecond time transfer. This performance is demonstrated by the results of testing at and between NRL and USNO. The modems use Code Division Multiple Access (CDMA) methods to separate their signals through a single path in the satellite. Each modem transmitted a different Pseudo Random Noise (PRN) code and received the others PRN code. High precision time transfer is possible with two way methods because of reciprocity of many of the terms of the path and hardware delay between the two modems. The hardware description was given in a previous paper.

Development of a UAV-based Global Ozone Lidar Demonstrator (GOLD)

NASA Astrophysics Data System (ADS)

Browell, E. V.; Deyoung, R. J.; Hair, J. W.; Ismail, S.; McGee, T.; Hardesty, R. M.; Brewer, W. A.; McDermid, I. S.

2006-12-01

Global ozone measurements are needed across the troposphere with high vertical resolution to enable comprehensive studies of continental and intercontinental atmospheric chemistry and dynamics, which are affected by diverse natural and human-induced processes. The development of a unattended aerial vehicle (UAV) based Global Ozone Lidar Demonstrator (GOLD) is an important step in enabling a space-based ozone and aerosol lidar and for conducting unique UAV-based large-scale atmospheric investigations. The GOLD system will incorporate the most advanced technology developed under the NASA Laser Risk Reduction Program (LRRP) and the Small Business Innovative Research (SBIR) program to produce a compact, autonomously operating ozone and aerosol Differential Absorption Lidar (DIAL) system for a UAV platform. This system will leverage advanced Nd:YAG and optical parametric oscillator (OPO) laser technologies being developed by ITT Industries under the LRRP and the autonomously operating ozone DIAL system being developed by Science and Engineering Services Inc. (SESI) under an SBIR Phase-3 contract. Laser components from ITT will be integrated into the SESI DIAL system, and the resulting GOLD system will be flight tested on a NASA UAV. The development of the GOLD system was initiated as part of the NASA Instrument Incubator Program in December 2005, and great progress has been made towards completing major GOLD subsystems. ITT has begun construction of the high-power Nd:YAG pump laser and the ultraviolet OPO for generating the ozone DIAL wavelengths of 290 and 300 nm and the aerosol visible wavelength at 532 nm. SESI is completing the Phase-3 SBIR contract for the delivery and demonstration of the ozone DIAL receiver and data system, and NOAA is completing detector evaluations for use in the GOLD system. Welch Mechanical is examining system designs for integrating GOLD into the external pod that will be hung under the new IKANA (Predator-B) UAV that NASA Dryden is acquiring. Details of the GOLD system design and development will be presented in this paper, and science applications for a UAV-based and space-based ozone lidar will be discussed.

Raman shifting of KrF laser radiation for tropospheric ozone measurements

NASA Technical Reports Server (NTRS)

Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Ismail, Syed

1991-01-01

The differential absorption lidar (DIAL) measurement of tropospheric ozone requires use of high average power UV lasers operating at two appropriate DIAL wavelengths. Laboratory experiments have demonstrated that a KrF excimer laser can be used to generate several wavelengths with good energy conversion efficiencies by stimulated Raman shifting using hydrogen (H2) and deuterium (D2). Computer simulations for an airborne lidar have shown that these laser emissions can be used for the less than 5 percent random error, high resolution measuremment of ozone across the troposphere using the DIAL technique. In the region of strong ozone absorption, laser wavelengths of 277.0 and 291.7 nm were generated using H2 and D2, respectively. In addition, a laser wavelength at 302.0 nm was generated using two cells in series, with the first containing D2 and the second containing H2. The energy conversion efficiency for each wavelength was between 14 and 27 percent.

Flight tests of a range-resolved airborne dial with two min-tea CO2 lasers

NASA Technical Reports Server (NTRS)

Itabe, T.; Ishizu, M.; Aruga, T.; Igarashi, T.; Asai, K.

1986-01-01

It is important to measure regional distributions of ozone concentrations in a short time for understanding a mechanism of photo-chemical smog development. An airborne Differential Absorption Lidar (DIAL) system with two low-power mini-TEA CO2 lasers was developed for measuring three-dimensional distributions of ozone in the lower troposphere. The CO2 DIAL is a nadir-looking system and is designed to measure ozone profiles between ground and airplane by using atmospheric aerosols as a distributed radar target. First flight test with a single laser were conducted in February 1985 over the Tokyo area. The system was operated at an altitude of 5000 ft. Results of the first flight tests show that the height profiles of the received power in the boundary layer were different between over land and ocean. The received power has to be inverted to an expression of a single optical parameter to see real aerosol distributions. Inversion of the lidar signal to the aerosol extinction was performed by using Klett's solution.

ISDN: The Digital Difference.

ERIC Educational Resources Information Center

Piedmo, Greg

1995-01-01

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

Differential Absorption Lidar (DIAL) Measurements from Air and Space

NASA Technical Reports Server (NTRS)

Browell, E. V.; Ismail, S.; Grant, W. B.

1998-01-01

Differential absorption lidar (DIAL) systems have been used for the measurement of ozone, water vapor, and aerosols from aircraft platforms for over 18 years, yielding new insights into atmospheric chemistry, composition, and dynamics in large-scale field experiments conducted all over the world. The successful deployment of the lidar in-space technology experiment (LITE) in September 1994 demonstrated that space-based lidars can also collect valuable information on the global atmosphere. This paper reviews some of the contributions of the NASA Langley Research Center's airborne ozone and water vapor DIAL systems and space-based LITE system to the understanding of the atmosphere and discusses the feasibility and advantages of putting DIAL systems in space for routine atmospheric measurements of ozone and/or water vapor and aerosols and clouds. The technology and applications of the differential absorption lidar (DIAL) technique have progressed significantly since the first DIAL measurements of Schotland, and airborne DIAL measurements of ozone and water vapor are frequently being made in a wide range of field experiments. In addition, plans are underway to develop DIAL systems for use on satellites for continuous global measurements. This paper will highlight the history of airborne lidar and DIAL systems, summarize the major accomplishments of the NASA Langley DIAL program, and discuss specifications and goals for DIAL systems in space.

76 FR 36154 - In the Matter of Certain Equipment for Communications Networks, Including Switches, Routers...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-21

... Communications Networks, Including Switches, Routers, Gateways, Bridges, Wireless Access Points, Cable Modems, IP... networks, including switches, routers, gateways, bridges, wireless access points, cable modems, IP phones... points, cable modems, IP phones, and products containing same that infringe one or more of claims 1, 5, 9...

The Electronic Flight Bag: A Multi-Function Tool for the Modern Cockpit

DTIC Science & Technology

2002-08-01

56K Modem , Sound Card, Touchscreen USB, PCMCIA, IR, 56K Modem , Sound Card, Touchscreen USB, IrDA, PCMCIA, Wireless LAN, Touchscreen, Integrated...card, internal modem and augmented internal battery. It is designed to complement the PID for use in the classroom at home or on the road.59

Textural and Carbon Isotopic Analyses of Modern Carbonate Microbialites: Possible Ancient and Martian Analogs

NASA Technical Reports Server (NTRS)

Thompson, Joel B.

1998-01-01

Many modem and ancient carbonate deposits around the world have been recognized as microbial buildups or microbialites. Ancient microbialite structures have been divided into two basic categories based on their internal fabric or texture. They include stromatolites which have a predominantly laminated internal fabric and thrombolites which have an open-porous clotted fabric, that lacks laminae. The origin of these two basic microbial fabrics is still being debated in the literature. Understanding the origin and the various microorganisms involved in forming these modem fabrics is the key to the interpretation of similar fabrics in ancient and possibly Martian rocks. Therefore, detailed studies are needed on the microbiological makeup and origin of the fabrics in modem microbialites. Such studies may serve as analogs for ancient and Martian microbialites in the future. The purpose of this study is to examine the textures and carbon isotopic signatures of the following modem microbialites from the Bahamas: 1) a modem subtidal microbialite from Iguana Cay, Bahamas and 2) a modem microbial mat (stromatolite) from a hypersaline pond on Lee Stocking Island, Bahamas.

Dolphin Sounds-Inspired Covert Underwater Acoustic Communication and Micro-Modem

PubMed Central

Qiao, Gang; Liu, Songzuo; Bilal, Muhammad

2017-01-01

A novel portable underwater acoustic modem is proposed in this paper for covert communication between divers or underwater unmanned vehicles (UUVs) and divers at a short distance. For the first time, real dolphin calls are used in the modem to realize biologically inspired Covert Underwater Acoustic Communication (CUAC). A variety of dolphin whistles and clicks stored in an SD card inside the modem helps to realize different biomimetic CUAC algorithms based on the specified covert scenario. In this paper, the information is conveyed during the time interval between dolphin clicks. TMS320C6748 and TLV320AIC3106 are the core processors used in our unique modem for fast digital processing and interconnection with other terminals or sensors. Simulation results show that the bit error rate (BER) of the CUAC algorithm is less than 10−5 when the signal to noise ratio is over ‒5 dB. The modem was tested in an underwater pool, and a data rate of 27.1 bits per second at a distance of 10 m was achieved. PMID:29068363

Pornography and Sexual Aggression

DTIC Science & Technology

1991-01-01

Dial-a- Porn .......................................8a Videocassettes.................................... 9 Pornographic Magazines...well known pornographic film, DeeR Throat, cost only M25,000 to produce, and has earned more than $50 million in profits.10 DIAL-A- PORN Dial-a- Porn has...Estimated costs for establishing a twenty-five dial-a- porn utility, including advertising, is $25,000.1 1 A typical dial-a- porn recording delivers an

New laser design for NIR lidar applications

NASA Astrophysics Data System (ADS)

Vogelmann, H.; Trickl, T.; Perfahl, M.; Biggel, S.

2018-04-01

Recently, we quantified the very high spatio-temporal short term variability of tropospheric water vapor in a three dimensional study [1]. From a technical point of view this also depicted the general requirement of short integration times for recording water-vapor profiles with lidar. For this purpose, the only suitable technique is the differential absorption lidar (DIAL) working in the near-infrared (NIR) spectral region. The laser emission of most water vapor DIAL systems is generated by Ti:sapphire or alexandrite lasers. The water vapor absorption band at 817 nm is predominated for the use of Ti:sapphire. We present a new concept of transversely pumping in a Ti:Sapphire amplification stage as well as a compact laser design for the generation of single mode NIR pulses with two different DIAL wavelengths inside a single resonator. This laser concept allows for high output power due to repetitions rates up to 100Hz or even more. It is, because of its compactness, also suitable for mobile applications.

Current 2-μm dial measurements of atmospheric CO2 and expected results from space using new MCT APDS

NASA Astrophysics Data System (ADS)

Dumas, A.; Gibert, F.; Rothman, J.; Édouart, D.; Le Mounier, F.; Cénac, C.

2017-11-01

In the framework of CO2 monitoring in the Atmospheric Boundary Layer (ABL), a ground-based 2-μm Differential Absorption Lidar (DIAL) has been developed at the Laboratoire de Météorologie Dynamique (LMD) in Palaiseau. In order to derive flux information, this system has been set up with coherent detection, which allows to combine CO2 density measurements with wind velocity measurements. On the other hand, new advances in the field of Mercury Cadmium Tellure (MCT) Avalanche Photodiodes (APDs) open the way for high-precision measurements in direct detection ultimately from space. In this study, we first report on state of the art measurements obtained with the current coherent DIAL system before presenting expected results for a similar laser transmitter equipped with MCT APDs. For this latter part, we use a numerical model which relies on APDs performance data provided by the Laboratoire d'Électronique et de Technologie de l'Information (LETI).

The necessity of clinical application of tibial reduction for detection of underestimated posterolateral rotatory instability in combined posterior cruciate ligament and posterolateral corner deficient knee.

PubMed

Lee, Han-Jun; Park, Yong-Beom; Ko, Young-Bong; Kim, Seong-Hwan; Kwon, Hyeok-Bin; Yu, Dong-Seok; Jung, Young-Bok

2015-10-01

The purpose of this study was to evaluate the usefulness of tibial reduction during dial test for clinical detection of underestimated posterolateral rotatory instability (PLRI) in combined posterior cruciate ligament (PCL)-posterolateral corner (PLC) deficient knee in terms of external rotation laxity and clinical outcomes. Twenty-one patients who classified as grade I PLRI using dial test with subluxated tibia, but classified as grade II with tibial reduction evaluated retrospectively. The mean follow-up was 39.3 months (range 24-61 months). Each patient was evaluated by the following variables: posterior translation and varus laxity on radiograph, KT-1000 arthrometer, dial test (reduced and subluxated position), International Knee Documentation Committee, Orthopädische Arbeitsgruppe Knie scoring system and Tegner activity scale. There were significant improvements in posterior tibial translation (8.6 ± 2.0 to 2.1 ± 1.0 mm; P < 0.001), varus laxity (3.3 ± 1.3 to 1.4 ± 0.5 mm; P < 0.001) and external rotation (13.2° ± 0.8° to 3.6° ± 1.1° at 30°, 13.3° ± 0.9° to 3.6° ± 0.9° at 90°; P < 0.001). The clinical scores were improved significantly at the last follow-up (P < 0.001). The external tibial rotation during dial test with tibial reduction increased from 6.8° ± 0.9 to 13.2° ± 0.8° at 30° of knee flexion, from 7.0° ± 0.8° to 13.3° ± 0.9° at 90° (P < 0.001). The clinical application of reduction of posteriorly subluxated tibia during the dial test was essential for an appropriate treatment of underestimated PLRI in combined PCL-PLC deficient knee. Retrospective case series, Level IV.

Performances of a date dissemination code on telephone lines using commercial modems

NASA Technical Reports Server (NTRS)

Cordara, F.; Pettiti, V.; Quasso, R.; Rubiola, E.

1993-01-01

A coded time/date information dissemination system (CTD), based on telephone lines and commercial modems, is now in its experimental phase in Italy at IEN. This service, born from a cooperation with other metrological laboratories (TUG, Austria, SNT, Sweden, VSL, The Netherlands), represents an attempt towards an European standardization. Some results of an experimental analysis in which a few modems were tested, both in laboratory conditions and connected to the telephone network, in order to evaluate the timing capability of the system are given. When the system is used in a one-way mode, in many practical cases the modems delay turns out to be the main factor which limits the accuracy, even more than the telephone line delays. If the two-way mode is used, the modems asymmetry, i.e., the delay difference between transmission and reception, is almost always the most important source of uncertainty, provided the link is not including a space segment. Comparing the widely used V.22 modems to the old V.21 ones, the latters turn out to be better both in delay time (30-100 ms V.22, and 7-15 ms V.21) and asymmetry (10-50 micro-s V.22, and 10 ms V.22). Time transfer accuracies of 10 micron-s (same turn) to 100 micro-s (long distance calls) were obtained in two-way mode with commercial V.21 modems.

Space Based Communications

NASA Technical Reports Server (NTRS)

Simpson, James; Denson, Erik; Valencia, Lisa; Birr, Richard

2003-01-01

Current space lift launches on the Eastern and Western Range require extensive ground-based real-time tracking, communications and command/control systems. These are expensive to maintain and operate and cover only limited geographical areas. Future spaceports will require new technologies to provide greater launch and landing opportunities, support simultaneous missions, and offer enhanced decision support models and simulation capabilities. These ranges must also have lower costs and reduced complexity while continuing to provide unsurpassed safety to the public, flight crew, personnel, vehicles and facilities. Commercial and government space-based assets for tracking and communications offer many attractive possibilities to help achieve these goals. This paper describes two NASA proof-of-concept projects that seek-to exploit the advantages of a space-based range: Iridium Flight Modem and Space-Based Telemetry and Range Safety (STARS). Iridium Flight Modem uses the commercial satellite system Iridium for extremely low cost, low rate two-way communications and has been successfully tested on four aircraft flights. A sister project at Goddard Space Flight Center's (GSFC) Wallops Flight Facility (WFF) using the Globalstar system has been tested on one rocket. The basic Iridium Flight Modem system consists of a L1 carrier Coarse/Acquisition (C/A)-Code Global Positioning System (GPS) receiver, an on-board computer, and a standard commercial satellite modem and antennas. STARS uses the much higher data rate NASA owned Tracking and Data Relay Satellite System (TDRSS), a C/A-Code GPS receiver, an experimental low-power transceiver, custom built command and data handler processor, and digitized flight termination system (FTS) commands. STARS is scheduled to fly on an F-15 at Dryden Flight Research Center in the spring of 2003, with follow-on tests over the next several years.

CO2 lidar for measurements of trace gases and wind velocities

NASA Technical Reports Server (NTRS)

Hess, R. V.

1982-01-01

CO2 lidar systems technology and signal processing requirements relevant to measurement needs and sensitivity are discussed. Doppler processing is similar to microwave radar, with signal reception controlled by a computer capable of both direct and heterodyne operations. Trace gas concentrations have been obtained with the NASA DIAL system, and trace gas transport has been determined with Doppler lidar measurements for wind velocity and turbulence. High vertical resolution measurement of trace gases, wind velocity, and turbulence are most important in the planetary boundary layer and in regions between the PBL and the lower stratosphere. Shear measurements are critical for airport operational safety. A sensitivity analysis for heterodyne detection with the DIAL system and for short pulses using a Doppler lidar system is presented. The development of transient injection locking techniques, as well as frequency stability by reducing chirp and catalytic control of closed cycle CO2 laser chemistry, is described.

Future Integrated Architecture (FIA): A Proposed Space Internetworking Architecture for Future Operations

DTIC Science & Technology

2008-09-01

WiMax “as a ‘last mile’ broadband wireless access (BWA) alternative to cable modem service, telephone company Digital Subscriber Line (DSL) or T1/E1...MUOS at 56k , shows results similar to another simulation with different circuit configurations. Analysis presented in this thesis shows adequate

Modern Amphibious Operations: Why the United States Must Maintain a Joint Amphibious Forcible Entry Capability

DTIC Science & Technology

2012-03-23

be reminded that the aforementioned movies depicted events that happened nearly 70 years ago.48 These films neither represent modem amphibious...contemporary sources. Few are more contemporary than those in this genre . Nothing can substitute a simple Google web search to get ideas about where

Model verifies design of mobile data modem

NASA Technical Reports Server (NTRS)

Davarian, F.; Sumida, J.

1986-01-01

It has been proposed to use differential minimum shift keying (DMSK) modems in spacecraft-based mobile communications systems. For an employment of these modems, it is necessary that the transmitted carrier frequency be known prior to signal detection. In addition, the time needed by the receiver to lock onto the carrier frequency must be minimized. The present article is concerned with a DMSK modem developed for the Mobile Satellite Service. This device demonstrated fast acquisition time and good performance in the presence of fading. However, certain problems arose in initial attempts to study the acquisition behavior of the AFC loop through breadboard techniques. The development of a software model of the AFC loop is discussed, taking into account two cases which were plotted using the model. Attention is given to a demonstration of the viability of the modem by an approach involving modeling and analysis of the frequency synchronizer.

WALES: water vapour lidar experiment in space

NASA Astrophysics Data System (ADS)

Guerin, F.; Pain, Th.; Palmade, J.-L.; Pailharey, E.; Giraud, D.; Jubineau, F.

2017-11-01

The WAter vapour Lidar Experiment in Space (WALES) mission aims at providing water vapour profiles with high accuracy and vertical resolution through the troposphere and the lower stratosphere on a global scale using an instrument based on Differential Absorption Lidar (DIAL) observation technique, and mounted on an Earth orbiting satellite. This active DIAL technique will also provide data on the cloud coverage by means of the signal reflection on the cloud layers. In DIAL operation, backscatter lidar signals at two wavelengths - at least - are detected. One wavelength (λ ON) is highly absorbed by the species of interest, while the other (λ OFF) is backscattered with minimal absorption. This difference in absorption at the two transmitted wavelengths leads to the determination of the concentration of the species of interest. The DIAL is therefore a dual-wavelength lidar in which the signals detected at the two wavelengths are processed to extract the absolute density of water vapour. The Phase A study performed by ALCATEL Space and their partners under contract of the European Space Agency has led to a credible and innovative concept of instrument, based on a mission performance modelling. The challenge is to foster the scientific return while minimising the development risks and costs of instrument development, in particular the laser transmitter. The paper describes the payload design and the implementation on a low Earth orbiting (LEO) satellite.

WALES: WAter vapour Lidar Experiment in Space

NASA Astrophysics Data System (ADS)

Guerin, F.; Pain, Th.; Palmade, J. L.; Pailharey, E.; Giraud, D.; Jubineau, F.

2004-06-01

The WAter vapour Lidar Experiment in Space (WALES) mission aims at providing water vapour profiles with high accuracy and vertical resolution through the troposphere and the lower stratosphere on a global scale using an instrument based on Differential Absorption Lidar (DIAL) observation technique, and mounted on an Earth orbiting satellite. This active DIAL technique will also provide data on the cloud coverage by means of the signal reflection on the cloud layers. In DIAL operation, backscatter lidar signals at two wavelengths - at least - are detected. One wavelength (λ ON) is highly absorbed by the species of interest, while the other (λ OFF) is backscattered with minimal absorption. This difference in absorption at the two transmitted wavelengths leads to the determination of the concentration of the species of interest. The DIAL is therefore a dual-wavelength lidar in which the signals detected at the two wavelengths are processed to extract the absolute density of water vapour. The Phase A study performed by ALCATEL Space and their partners under contract of the European Space Agency has led to a credible and innovative concept of instrument, based on a mission performance modelling. The challenge is to foster the scientific return while minimising the development risks and costs of instrument development, in particular the laser transmitter. The paper describes the payload design and the implementation on a low Earth orbiting (LEO) satellite.

Comparison of Online Costs Using 1200-BPS and 2400-BPS Modems.

ERIC Educational Resources Information Center

MacMillan, Donald

1992-01-01

Compares search time and costs of four online searches, identically replicated except for the speed of the modem used to retrieve and download data. Results are presented for 1200-BPS (bits per second) and 2400-BPS modems which demonstrate that searching at 2400-BPS is more efficient and economical. Issues to be resolved before 9600-BPS modems…

Simple, Affordable and Sustainable Borehole Observatories for Complex Monitoring Objectives

NASA Astrophysics Data System (ADS)

Kopf, A.; Freudenthal, T.; Ratmeyer, V.; Wefer, G.

2014-12-01

Seafloor drill rigs are remotely operated systems that provide a cost effective means to recover sedimentary records of the upper sub-seafloor deposits. Recent increases in their payload included downhole logging tools or autoclave coring systems. We here report on another milestone in using seafloor rigs: The development and installation of shallow borehole observatories. Three different systems have been developed for the MeBo seafloor drill, which is operated by MARUM, Univ. Bremen, Germany. A simple design, the MeBoPLUG, separates the inner borehole from the overlying ocean by using o-ring seals at the conical threads of the drill pipe. The systems are self-contained and include data loggers, batteries, thermistors and a differential pressure sensor. A second design, the so-called MeBoCORK, is more sophisticated and also hosts an acoustic modem for data transfer and, if desired, fluid sampling capability using osmotic pumps. Of these MeBoCORKs, two systems have to be distinguished: The CORK-A (A = autonomous) can be installed by the MeBo alone and monitors pressure and temperature inside and above the borehole (the latter for reference). The CORK-B (B = bottom) has a higher payload and can additionally be equipped with geochemical, biological or other physical components. Owing to its larger size, it is installed by ROV and utilises a hotstab connection in the upper portion of the drill string. Either design relies on a hostab connection from beneath which coiled tubing with a conical drop weight is lowered to couple to the formation. These tubes are fluid-saturated and either serve to transmit pore pressure signals or collect pore water in the osmo-sampler. The third design, the MeBoPUPPI (Pop-Up Pore Pressure Instrument), is similar to the MeBoCORK-A and monitors pore pressure and temperature in a self-contained manner. Instead of transferring data upon command using an acoustic modem, the MeBoPUPPI contains a pop-up telemetry with Iridium link. After a predefined period, the data unit with satellite link is released, ascends to the sea surface, and remains there for up to two weeks while sending the long-term data sets to shore. In 2012, 2 MeBoPLUGs, 1 MeBoCORK-A and 1 MeBoCORK-B were installed with MeBo in the Nankai Trough, Japan, and data were successfully downloaded from the CORKs.

Design and implementation of an omni-directional underwater acoustic micro-modem based on a low-power micro-controller unit.

PubMed

Won, Tae-Hee; Park, Sung-Joon

2012-01-01

For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication.

Design and development of a compact lidar/DIAL system for aerial surveillance of urban areas

NASA Astrophysics Data System (ADS)

Gaudio, P.; Gelfusa, M.; Malizia, A.; Richetta, M.; Antonucci, A.; Ventura, P.; Murari, A.; Vega, J.

2013-10-01

Recently surveying large areas in an automatic way, for early detection of harmful chemical agents, has become a strategic objective of defence and public health organisations. The Lidar-Dial techniques are widely recognized as a cost-effective alternative to monitor large portions of the atmosphere but, up to now, they have been mainly deployed as ground based stations. The design reported in this paper concerns the development of a Lidar-Dial system compact enough to be carried by a small airplane and capable of detecting sudden releases in air of harmful and/or polluting substances. The proposed approach consists of continuous monitoring of the area under surveillance with a Lidar type measurement. Once a significant increase in the density of backscattering substances is revealed, it is intended to switch to the Dial technique to identify the released chemicals and to determine its concentration. In this paper, the design of the proposed system is described and the simulations carried out to determine its performances are reported. For the Lidar measurements, commercially available Nd- YAG laser sources have already been tested and their performances, in combination with avalanche photodiodes, have been experimentally verified to meet the required specifications. With regard to the DIAL measurements, new compact CO2 laser sources are being investigated. The most promising candidate presents an energy per pulse of about 50 mJ typical, sufficient for a range of at least 500m. The laser also provides the so called "agile tuning" option that allows to quickly tune the wavelength. To guarantee continuous, automatic surveying of large areas, innovative solutions are required for the data acquisition, self monitoring of the system and data analysis. The results of the design, the simulations and some preliminary tests illustrate the potential of the chosen, integrated approach.

Pilot Preferences for Information Provided and Its Format for Status, Alerts, and Controls

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.

2004-01-01

With the increased use of cathode ray tubes (CRTs) in flight decks and the computing power available, it is possible to combine status screens, alerts/procedures screens, and control screens onto a single display. This report presents the results of a survey designed to assess the perceived helpfulness and need of various pieces of information that could be included on status and control screens. The results from the survey indicate that operators want parameter ranges that change depending on the current aircraft configuration shown on bow-tie or dial displays. These displays should show the current value, normal range, alert type and range, and predictive information. Respondents wanted to see system relationships to one another for both component control and menu selection. When bringing up these various displays, this information should come up with a single button push. Finally, checklists should sense when a component has changed to the desired state.

47 CFR 51.215 - Dialing parity: Cost recovery.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) INTERCONNECTION Obligations of All Local Exchange Carriers § 51.215 Dialing parity: Cost recovery. (a) A LEC may recover the incremental costs necessary for the implementation of toll dialing parity... 47 Telecommunication 3 2010-10-01 2010-10-01 false Dialing parity: Cost recovery. 51.215 Section...

Chemistry and dynamics of the lower troposphere over North America and the North Atlantic Ocean in fall 1997 observed using an airborne UV DIAL system

NASA Technical Reports Server (NTRS)

Grant, William B.; Butler, Carolyn F.; Fenn, Marta A.; Kooi, Susan A.; Browell, Edward V.; Fuelberg, Henry

1998-01-01

The NASA Langley Research Center's airborne UV Differential Absorption Lidar (DIAL) system participated in the Subsonic Assessment, Ozone and Nitrogen Oxide Experiment (SONEX) mission from October 13 to November 12, 1997. The purpose of the mission was to study the upper troposphere/lower stratosphere in and near the North Atlantic flight corridor to better understand this region of the atmosphere and how civilian air travel in the corridor might be affecting the atmospheric chemistry. Bases of operations included NASA Ames, California (37.4 deg N, 122.1 deg W); Bangor, Maine (44.8 deg N, 68.8 deg W); Shannon, Ireland (52.7 deg N, 8.9 deg W); and Lajes, Terceira Island, Azores (38.8 deg N, 27.1 deg W). Since the UV DIAL system observes in the nadir as well as the zenith, aerosol and ozone data were obtained from near the Earth's surface to the lower stratosphere. A number of interesting features were noted relating to both chemistry and dynamics of the troposphere, which are reported here.

USSR Report, Cybernetics, Computers and Automation Technology

DTIC Science & Technology

1985-08-28

alphanumerical dis- plays SM 7206 and SM 7401, graphics displays SM 7300 and SM 7301, modems SM 8105, SM 8107 and SM 8108, and so on. Today it is...3 are written in assembler and PL-1. They require 56k to 200 k memory for operation. S0RT-7/SM sorting subsystem was developed in conjunction with

A spread-spectrum modem using constant envelope BPSK for a mobile satellite communications terminal

NASA Technical Reports Server (NTRS)

Iizuka, N.; Yamashita, A.; Takenaka, S.; Morikawa, E.; Ikegami, T.

1990-01-01

This paper describes a 5-kilobit/s spread spectrum modem with a 1.275 mega-Hz chip rate for mobile satellite communications. We used a Viterbi decoder with a coding gain of 7.8 dB at a BER of 10(exp -5) to decrease the required receiver power. This reduces the cost of communication services. The spread spectrum technique makes the modem immune to terrestrial radio signals and keeps it from causing interference in terrestrial radio systems. A class C power amplifier reduces the modem's power consumption. To avoid nonlinear distortion caused by the amplifier, the envelope of the input signal is kept constant by adding quadrature channel signal to the BPSK signal. To simulate the worst case, we measured the modem's output spectrum using a limiting amplifier instead of the class C amplifier, and found that 99 percent of the spectral power was confined to the specified 2.55 mega-Hz bandwidth.

Ground-based DIAL and IPDA Systems for Remote Sensing of CO2, CH4, and H2O near 1.6 µm

NASA Astrophysics Data System (ADS)

Wagner, G. A.; Plusquellic, D. F.

2017-12-01

Integrated path differential absorption (IPDA) and differential absorption LIDAR (DIAL) are well established methods to monitor atmospheric constituents. At NIST, IPDA and DIAL systems have been developed as standoff systems and their overall performance has been evaluated through intercomparisons including the traceability to point sensor measurements. The all-fiber IPDA system is based on a low-power (< 13 mW, eye-safe) electro-optic modulated continuous-wave laser to produce 123 frequencies at a scan repetition frequency of 10 kHz.1 The transmitter-receiver system measures backscatter from natural targets and is rastered during the measurements to reduce speckle effects. The receiver consists of a 28 cm telescope, photomultiplier tube, and a streaming data acquisition system for direct photon discrimination and counting. The eye-safe DIAL system is based on an optical parametric oscillator2,3 that operates at a pulse repetition frequency of 100 Hz and alternates between on-line and off-line frequencies with pulse energies of < 10 mJ/pulse. The receivers consist of two telescopes (near field: 28 cm; far field: 40 cm), photomultiplier tubes, and a 2 GS/s hybrid data acquisition system for photon counting and current detection. We demonstrate the performance of the DIAL and IPDA systems and present results of a CO2 IPDA/DIAL/point sensor traceability study performed in Boulder (CO, USA) in summer 2017. 1. G. A. Wagner and D. F. Plusquellic, "Ground-Based, Integrated Path Differential Absorption LIDAR Measurement of CO2, CH4 and H2O near 1.6 µm," Applied Optics, 55(23), 6292-6310 (2016). 2. D. J. Armstrong, and A. V. Smith, "150-mJ 1550-nm KTA OPO with Good Beam Quality and High Efficiency," SPIE, 5337, 71-80 (2004). 3. K. O. Douglass, S. E. Maxwell, D. F. Plusquellic, J. T. Hodges, R. D. van Zee, D. V. Samarov, J. R. Whetstone, "Construction of a High Power OPO Laser System for Differential Absorption LIDAR," SPIE, 8159, 81590D (2011).

Modem design for a MOBILESAT terminal

NASA Technical Reports Server (NTRS)

Rice, M.; Miller, M. J.; Cowley, W. G.; Rowe, D.

1990-01-01

The implementation is described of a programmable digital signal processor based system, designed for use as a test bed in the development of a digital modem, codec, and channel simulator. Code was written to configure the system as a 5600 bps or 6600 bps QPSK modem. The test bed is currently being used in an experiment to evaluate the performance of digital speech over shadowed channels in the Australian mobile satellite (MOBILESAT) project.

47 CFR 51.207 - Local dialing parity.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 3 2013-10-01 2013-10-01 false Local dialing parity. 51.207 Section 51.207... Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit telephone exchange service customers within a local calling area to dial the same number of digits to make a local...

47 CFR 51.207 - Local dialing parity.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Local dialing parity. 51.207 Section 51.207... Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit telephone exchange service customers within a local calling area to dial the same number of digits to make a local...

47 CFR 51.207 - Local dialing parity.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Local dialing parity. 51.207 Section 51.207... Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit telephone exchange service customers within a local calling area to dial the same number of digits to make a local...

47 CFR 51.207 - Local dialing parity.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Local dialing parity. 51.207 Section 51.207... Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit telephone exchange service customers within a local calling area to dial the same number of digits to make a local...

47 CFR 51.207 - Local dialing parity.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 3 2012-10-01 2012-10-01 false Local dialing parity. 51.207 Section 51.207... Obligations of All Local Exchange Carriers § 51.207 Local dialing parity. A LEC shall permit telephone exchange service customers within a local calling area to dial the same number of digits to make a local...

Alternative treatment technology information center computer database system

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

Sullivan, D.

1995-10-01

The Alternative Treatment Technology Information Center (ATTIC) computer database system was developed pursuant to the 1986 Superfund law amendments. It provides up-to-date information on innovative treatment technologies to clean up hazardous waste sites. ATTIC v2.0 provides access to several independent databases as well as a mechanism for retrieving full-text documents of key literature. It can be accessed with a personal computer and modem 24 hours a day, and there are no user fees. ATTIC provides {open_quotes}one-stop shopping{close_quotes} for information on alternative treatment options by accessing several databases: (1) treatment technology database; this contains abstracts from the literature on all typesmore » of treatment technologies, including biological, chemical, physical, and thermal methods. The best literature as viewed by experts is highlighted. (2) treatability study database; this provides performance information on technologies to remove contaminants from wastewaters and soils. It is derived from treatability studies. This database is available through ATTIC or separately as a disk that can be mailed to you. (3) underground storage tank database; this presents information on underground storage tank corrective actions, surface spills, emergency response, and remedial actions. (4) oil/chemical spill database; this provides abstracts on treatment and disposal of spilled oil and chemicals. In addition to these separate databases, ATTIC allows immediate access to other disk-based systems such as the Vendor Information System for Innovative Treatment Technologies (VISITT) and the Bioremediation in the Field Search System (BFSS). The user may download these programs to their own PC via a high-speed modem. Also via modem, users are able to download entire documents through the ATTIC system. Currently, about fifty publications are available, including Superfund Innovative Technology Evaluation (SITE) program documents.« less

Metaheuristics for the dynamic stochastic dial-a-ride problem with expected return transports

PubMed Central

Schilde, M.; Doerner, K.F.; Hartl, R.F.

2011-01-01

The problem of transporting patients or elderly people has been widely studied in literature and is usually modeled as a dial-a-ride problem (DARP). In this paper we analyze the corresponding problem arising in the daily operation of the Austrian Red Cross. This nongovernmental organization is the largest organization performing patient transportation in Austria. The aim is to design vehicle routes to serve partially dynamic transportation requests using a fixed vehicle fleet. Each request requires transportation from a patient's home location to a hospital (outbound request) or back home from the hospital (inbound request). Some of these requests are known in advance. Some requests are dynamic in the sense that they appear during the day without any prior information. Finally, some inbound requests are stochastic. More precisely, with a certain probability each outbound request causes a corresponding inbound request on the same day. Some stochastic information about these return transports is available from historical data. The purpose of this study is to investigate, whether using this information in designing the routes has a significant positive effect on the solution quality. The problem is modeled as a dynamic stochastic dial-a-ride problem with expected return transports. We propose four different modifications of metaheuristic solution approaches for this problem. In detail, we test dynamic versions of variable neighborhood search (VNS) and stochastic VNS (S-VNS) as well as modified versions of the multiple plan approach (MPA) and the multiple scenario approach (MSA). Tests are performed using 12 sets of test instances based on a real road network. Various demand scenarios are generated based on the available real data. Results show that using the stochastic information on return transports leads to average improvements of around 15%. Moreover, improvements of up to 41% can be achieved for some test instances. PMID:23543641

Advanced Military Pay System Concepts. Evaluation of Opportunities through Information Technology.

DTIC Science & Technology

1980-07-01

trans- mdtter (UART) to interface with a modem . The main processor was then responsible for input and output between main memory and the UART...digital, "run-length" encoding scheme which is very effective in reducing the amount of data to be transmitted. Machines of this type include a modem ...Output control as well as data compression will be combined with appropriate modems or interfaces to digital transmission channels and microprocessor

DEFENSE RTD&E ONLINE SYSTEM (DROLS)

EPA Science Inventory

Web Enabled DROLS (WED) is a free subscription service available to registered users that provides online access to DTIC's Technical Reports and Research Summaries Databases. It replaces the former unclassified dial-up access to DROLS, DTIC's Defense RDT&E Online System. The Defe...

Tunable Single-Frequency Near IR Lasers for DIAL Applications

NASA Technical Reports Server (NTRS)

Henderson, Sammy W.; Marquardt, John H.; Carrig, Timothy J.; Gatt, Phil; Smith, Duane D.; Hale, Charley P.

2000-01-01

Tunable single-frequency sources in the 2-4 micron wavelength region are useful for remote DIAL measurements of chemicals and pollutants. We are developing tunable single-frequency transmitters and receivers for both direct and coherent detection lidar measurement applications. We have demonstrated a direct-diode-pumped PPLN-based OPO that operates single frequency, produces greater than 10 mW cw and is tunable over the 2.5 - 3.9 micron wavelength region. This laser has been used to injection seed a pulsed PPLN OPO, pumped by a 1.064 micron Nd:YAG laser, producing 50-100 microJoule single-frequency pulses at 100 Hz PRF near 3.6 micron wavelength. In addition, we have demonstrated a cw Cr:ZnSe laser that is tunable over the 2.1 - 2.8 micron wavelength region. This laser is pumped by a cw diode-pumped Tm:YALO laser and has produced over 1.8 W cw. Tm- and Tm, Ho-doped single-frequency solid-state lasers that produce over 50 mW cw and are tunable over approximately 10 nm in the 2 -2.1 micron band with fast PZT tuning have also been demonstrated. A fast PZT-tunable Tm, Ho:YLF laser was used for a direct-detection column content DIAL measurement of atmospheric CO2. Modeling shows that that all these cw and pulsed sources are useful for column-content coherent DIAL measurements at several km range using topographic targets.

Effects of historical and predictive information on ability of transport pilot to predict an alert

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.

1994-01-01

In the aviation community, the early detection of the development of a possible subsystem problem during a flight is potentially useful for increasing the safety of the flight. Commercial airlines are currently using twin-engine aircraft for extended transport operations over water, and the early detection of a possible problem might increase the flight crew's options for safely landing the aircraft. One method for decreasing the severity of a developing problem is to predict the behavior of the problem so that appropriate corrective actions can be taken. To investigate the pilots' ability to predict long-term events, a computer workstation experiment was conducted in which 18 airline pilots predicted the alert time (the time to an alert) using 3 different dial displays and 3 different parameter behavior complexity levels. The three dial displays were as follows: standard (resembling current aircraft round dial presentations); history (indicating the current value plus the value of the parameter 5 sec in the past); and predictive (indicating the current value plus the value of the parameter 5 sec into the future). The time profiles describing the behavior of the parameter consisted of constant rate-of-change profiles, decelerating profiles, and accelerating-then-decelerating profiles. Although the pilots indicated that they preferred the near term predictive dial, the objective data did not support its use. The objective data did show that the time profiles had the most significant effect on performance in estimating the time to an alert.

CVN’s, is Eleven Too Many or Too Few?

DTIC Science & Technology

2011-03-10

allows for transit and work ups for deployment. The complete cycle has one ship on post, one corning off post and one preparing to take post in each of...developed the Silk Missile, an. anti -ship missile that can sink a smaller vessel with one burst. Many of the defenses used in the modem carrier

An Ozone Differential Absorption Lidar (DIAL) Receiver System for Use on Unpiloted Atmospheric Vehicles

NASA Technical Reports Server (NTRS)

DeYoung, Russell J.; Goldschmidt, Soenke

1999-01-01

Measurements of global atmosphere ozone concentrations call for flexible lidar systems that can be operated from an unpiloted atmospheric vehicle (UAV) to reduce the cost of measurement missions. A lidar receiver system consisting of a fiber-optic-coupled telescope has been designed and tested for this purpose. The system weight is 13 kg and its volume of 0.06 m 3 would fit into the payload compartment of a Perseus B UAV. The optical efficiency of the telescope is 37 percent at 288 nm and 64 percent at 300 nm. Atmospheric measurements with a DIAL laser system have been performed, and the measured ozone density has matched the data from ozonesondes to an altitude of 7 km.

The Effects of 12 Hours of Low-Grade Hypoxia at 10,000 ft at Night in Special Operations Forces Aircraft Operations on Cognition, Night Vision, Goggle Vision and Subjective Symptoms

DTIC Science & Technology

2007-06-28

SUBJECTS 7 DURATION 7 DESCRIPTION OF EXPERIMENT 7 COGNITIVE PERFORMANCE BATTERY 8 WORK LOAD 10 VISUAL...Once During the Experimental Session vi LIST OF...shared performance on several sub tasks under experimenter manipulated workload conditions such as monitoring of dials and displays with dynamic

Introductory Talk: Whole Frog Project

Science.gov Websites

geometric primitives (points, lines, polygons, etc.) that accurately represent the shape of the surface constant value (color). This operation effectively defines the boundary between areas of different color about 10 seconds on a 56K baud modem. The controls can be set to send compressed images of 3 different

Modem Signature Analysis.

DTIC Science & Technology

1982-10-01

AD-A127 993 MODEM SIGNATURE ANALISIS (U) PAR TECHNOLOGY CORP NEW / HARTFORD NY V EDWARDS ET AL. OCT 82 RADC-TR-82-269 F30602-80-C-0264 NCLASSIFIED F/G...as an indication of the class clustering and separation between different classes in the modem data base. It is apparent from the projection that the...that as the clusters disperse, the likelihood of a sample crossing the boundary into an adjacent region and causing a symbol decision error increases. As

Mixed garnet laser for a water vapour DIAL

NASA Astrophysics Data System (ADS)

Treichel, Rainer; Strohmaier, Stephan; Nikolov, Susanne; Eichler, Hans-Joachim; Murphy, Eamonn

2017-11-01

For the water vapour DIAL "WALES" the wavelength regions around 935 nm, 942 nm and 944 nm have been identified as the most suitable wavelength ranges. These wavelengths can be obtained using opticalparametric-oscillators (OPOs), stimulated Raman shifters and the Ti-Sapphire laser but none of these systems could deliver all the needed parameters like beam quality, efficiency, pulse length and energy yet. Also these systems are comparably big and heavy making them less suitable for a satellite based application. A fourth possibility to achieve these wavelength ranges is to shift the quasi-3-level laser lines (938 nm and 946 nm) of the Nd:YAG laser by replacing aluminium and yttrium by other rare earth elements. Changes of the host lattice characteristics lead to a shift of the upper and lower laser levels. These modified crystals are summarized under the name of "Mixed Garnet" crystals. Only the Mixed Garnet lasers can be pumped directly with diode laser and use a direct approach to generate the required laser pulses without frequency conversion. Therefore no additional non-linear crystals or special pump lasers are needed and a higher electric to optical efficiency is expected as well as single frequency operation using spectral tuning elements like etalons. In a first phase such mixed garnet crystals had been grown and characterised. The outcome was the selection of the gadolinium-scandium garnet for the most suitable laser crystal. During a second phase the complete laser system with output energy about 18 mJ in single 20 ns pulses and up to 8 mJ in free running mode with a combined pulse width of 250 μs at 942 nm have been demonstrated. The results of the first laser operation and the achieved performance parameter are reported.

Coding and Modulation for LMDS and Analysis of the LMDS Channel

PubMed Central

Håkegård, Jan Erik

2000-01-01

Local Multipoint Distribution Service (LMDS) has the potential to become a viable alternative to coaxial cable, fiber and other wired and wireless technologies providing “last mile” communication services. A major obstacle, however, is the high equipment cost. While for example cable modems supporting two-way services are available for $200 to $300, LMDS modem providing similar services will cost over $1000. The major cost driver of LMDS equipment is the radio frequency (RF) unit, as Ka-band technology still is quite expensive. The modem design must minimize the overall architecture cost, and low-cost modems requiring an expensive architecture should not be used. The channel characteristics of LMDS systems are very different from those of fiber, coaxial cable, and lower frequency wireless links, major channel impairments being non-linear high power amplifier (HPA), high phase noise and high co-channel interference. Modems should therefore be developed specifically for LMDS systems. This report deals with the choice of coding and modulation schemes, the LMDS channel, and how the channel impairments should be overcome by digital signal processing algorithms. PMID:27551634

DialBetics

PubMed Central

Fujita, Hideo; Uchimura, Yuji; Omae, Koji; Aramaki, Eiji; Kato, Shigeko; Lee, Hanae; Kobayashi, Haruka; Kadowaki, Takashi; Ohe, Kazuhiko

2014-01-01

Numerous diabetes-management systems and programs for improving glycemic control to meet guideline targets have been proposed, using IT technology. But all of them allow only limited—or no—real-time interaction between patients and the system in terms of system response to patient input; few studies have effectively assessed the systems’ usability and feasibility to determine how well patients understand and can adopt the technology involved. DialBetics is composed of 4 modules: (1) data transmission module, (2) evaluation module, (3) communication module, and (4) dietary evaluation module. A 3-month randomized study was designed to assess the safety and usability of a remote health-data monitoring system, and especially its impact on modifying patient lifestyles to improve diabetes self-management and, thus, clinical outcomes. Fifty-four type 2 diabetes patients were randomly divided into 2 groups, 27 in the DialBetics group and 27 in the non-DialBetics control group. HbA1c and fasting blood sugar (FBS) values declined significantly in the DialBetics group: HbA1c decreased an average of 0.4% (from 7.1 ± 1.0% to 6.7 ± 0.7%) compared with an average increase of 0.1% in the non-DialBetics group (from 7.0 ± 0.9% to 7.1 ± 1.1%) (P = .015); The DialBetics group FBS decreased an average of 5.5 mg/dl compared with a non-DialBetics group average increase of 16.9 mg/dl (P = .019). BMI improvement—although not statistically significant because of the small sample size—was greater in the DialBetics group. DialBetics was shown to be a feasible and an effective tool for improving HbA1c by providing patients with real-time support based on their measurements and inputs. PMID:24876569

First open field measurements with a portable CO2 lidar/dial system for early forest fires detection

NASA Astrophysics Data System (ADS)

Gaudio, Pasquale; Gelfusa, Michela; Lupelli, Ivan; Malizia, Andrea; Moretti, Alessandro; Richetta, Maria; Serafini, Camilla; Bellecci, Carlo

2011-11-01

Lidar and dial are well established methods to explore the atmosphere. Different groups have already shown experimentally the possibility to measure the density variation of aerosol and particulate in the atmosphere due to plumes emitted in forest fires with this kind of systems. The aim of the present work is to demonstrate the capabilities of our mobile Lidar system, based on a CO2 laser, to detect forest fires and minimizing false alarms. For this purpose, our system can be operated in both lidar and dial configurations in sequence. The first Lidar measurement is performed to evaluate the variation of the local density into the atmosphere, using a nonabsorption water wavelength 10R18 (10.571 μm). If the returned signal reports a backscattering peak, the presence of a fire is probable. To confirm this hypothesis, a second dial measurement is carried out to reveal a second component emitted during the combustion process. The chosen second component is water vapour, which is, as it is well-known, largely produced during the first combustion stage. Measuring the water concentration peak after the detection of the aerosol density increment (referred to the standard mean atmospheric value) represents a good method to reduce false alarms with a dial system. In order to test this methodology, a first set of measurements has been performed in a field near the Engineering Faculty of the University of Rome "Tor Vergata". A quite small controlled-fire has been lighted into a box at a distance of about one kilometre from the system. The data acquired at the two wavelengths (10R18 and 10R20) have been averaged on 100 elastic backscattered Lidar signals. The first results confirm the effectiveness of the measurement strategy for reducing the number of false alarm preserving the early detection.

Apparatus and Method for Communication over Power Lines

NASA Technical Reports Server (NTRS)

Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor); Greer, III, Lawrence C. (Inventor); Nappier, Jennifer M. (Inventor)

2017-01-01

An apparatus and method are provided for communicating over power lines. The apparatus includes a coupling modem that is situated between a power line and a device. The coupling modem is configured to demodulate a signal received from the power line into a sine signal and a cosine signal. The coupling modem is also configured to modulate a communicated bit stream received from the device into a transmitted signal in order to impose the transmitted signal onto the power line.

An Impact Assessment Model for Distributed Adaptive Security Situation Assessment

DTIC Science & Technology

2005-01-01

the cargo manifest can be either a 56K modem-based TCP/IP connection (the oval labeled internet) or a 40K wireless modem connection ( cell phone ) that...via a UDP connection on the 40K wireless modem ( cell phone ). For each resource, either alternative may be used to achieve the same goal, but some...Manifests Comm-in Comp- power Comm- out JTF Internet (TCP-IP) Cell phone (TCP-IP) Internet (UDP) Cell phone (UDP) Manual Computer 4

Enhancing Network Communication in NPSNET-V Virtual Environments Using XML-Described Dynamic Behavior (DBP) Protocols

DTIC Science & Technology

2001-09-01

testing is performed between two machines connected by either a 100 Mbps Ethernet connection or a 56K modem connection. This testing is performed...and defined as follows: • The available bandwidth is set at two different levels (Ethernet 100 Mbps and 56K modem ). 32 • The packet size is set... modem connection. These two connections represent the target 100 Mbps high end and 56k bps low end of anticipated client connections in web-based

Computer Algorithms and Architectures for Three-Dimensional Eddy-Current Nondestructive Evaluation. Volume 3. Chapters 6-11

DTIC Science & Technology

1989-01-20

addressable memory can be loaded or off- loaded as the number crunching continues. Modem VLSI processors can often process data faster than today’s...Available DSP Chips Texas Instruments was one of the first serious manufacturers of DSP chips. With the Texas Instruments TMS310 DSP chip, modem , voice...Can handle double presicion data types. Texas Instruments TMS32010 T’s first-generation DSP design: a fixed-point DSP that has found its way into modem

Overview of Research Activities on Time and Frequency at the National Institute of Information and Communications Technology

DTIC Science & Technology

2004-12-01

FREQUENCY TRANSFER ( TWSTFT ) TWSTFT network in the Asia-Pacific region has developed by the collaboration of NICT and major T&F institutes in the...region [7]. A multi-channel TWSTFT modem has been developed by NICT. The performance evaluation shows that it is capable of sub-nanosecond time...intercomparison of NICT modem TWSTFT , ATLANTIS modem TWSTFT , and GPS common view (CV) in the case of the NICT-TL link is shown in Figure 4, and the stability

Apparatus and Method for Communication over Power Lines

NASA Technical Reports Server (NTRS)

Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor); Greer, Lawrence C., III (Inventor); Nappier, Jennifer M. (Inventor)

2015-01-01

An apparatus and method are provided for communicating over power lines. The apparatus includes a coupling modem that is situated between a power line and a device. The coupling modem is configured to demodulate a signal received from the power line into a sine signal and a cosine signal. The coupling modem is also configured to modulate a communicated bit stream received from the device into a transmitted signal in order to impose the transmitted signal onto the power line.

Internet Connections: Understanding Your Access Options.

ERIC Educational Resources Information Center

Notess, Greg R.

1994-01-01

Describes levels of Internet connectivity, physical connections, and connection speeds. Compares options for connecting to the Internet, including terminal accounts, dial-up terminal accounts, direct connections through a local area network, and direct connections using SLIP (Serial Line Internet Protocol) or PPP (Point-to-Point Protocol). (eight…

46 CFR 520.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... basic ocean freight rate. BTA means the Commission's Bureau of Trade Analysis or its successor bureau... carriers which provides for the fixing of and adherence to uniform tariff rates, charges, practices and... via dial-up telecommunications or a network link and interacts with the carrier's or publisher's...

46 CFR 520.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... basic ocean freight rate. BTA means the Commission's Bureau of Trade Analysis or its successor bureau... carriers which provides for the fixing of and adherence to uniform tariff rates, charges, practices and... via dial-up telecommunications or a network link and interacts with the carrier's or publisher's...

46 CFR 520.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... basic ocean freight rate. BTA means the Commission's Bureau of Trade Analysis or its successor bureau... carriers which provides for the fixing of and adherence to uniform tariff rates, charges, practices and... via dial-up telecommunications or a network link and interacts with the carrier's or publisher's...

46 CFR 520.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... basic ocean freight rate. BTA means the Commission's Bureau of Trade Analysis or its successor bureau... carriers which provides for the fixing of and adherence to uniform tariff rates, charges, practices and... via dial-up telecommunications or a network link and interacts with the carrier's or publisher's...

46 CFR 520.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... basic ocean freight rate. BTA means the Commission's Bureau of Trade Analysis or its successor bureau... carriers which provides for the fixing of and adherence to uniform tariff rates, charges, practices and... via dial-up telecommunications or a network link and interacts with the carrier's or publisher's...

Islam and Science

NASA Astrophysics Data System (ADS)

Salam, Abdus

The following sections are included: * The Holy Quran and Science * Modem Science, A Greco- Islamic Legacy * The Decline of Sciences in Islam * The Limitations of Science * Faith and Science * The Present Picture of Sciences in the Islamic Countries * Renaissance of Sciences in Islam * Steps Needed for Building up Sciences in the Islamic Countries * Science Education * Science Foundations in Islam * Technology in Our Countries * Concluding Remarks * REFERENCES

Using an Electronic Network To Create a Read Context for High School Writing.

ERIC Educational Resources Information Center

Schwartz, Jeffrey

In an effort to broaden the context for classroom writing by providing an audience other than the teacher and classmates, a study used microcomputers, a modem and an electronic mail service to set up communications with classes in other communities. Two classes (27 students) at Sewickley Academy in Pennsylvania communicated for a semester with two…

Mentoring by Modem. Connect for Kids: Guidance for Grown-Ups.

ERIC Educational Resources Information Center

Newberger, Julee

This article describes the use of an eMentoring program by the Orphan Foundation of America, a nonprofit organization dedicated to helping young people move out of foster care and into adult life. The eMentoring program, which allows youth and their mentors to communicate via e-mail, helps foster youth prepare for work life by matching them with…

The Design of an Interactive Computer Based System for the Training of Signal Corps Officers in Communications Network Management

DTIC Science & Technology

1985-08-01

from the mainframe to the terminals is approximately 56k bits per second (21:3). Score: 8. Expandability. The number of terminals available to the 0...the systems controllers may access any files. For modem link up, a callback system is to be implemented to prevent unauthorized off post access (10:2

Implementation and flight tests for the Digital Integrated Automatic Landing System (DIALS). Part 2: Complete set of flight data

NASA Technical Reports Server (NTRS)

Hueschen, R. M.

1986-01-01

Five flight tests of the Digital Automated Landing System (DIALS) were conducted on the Advanced Transport Operating System (ATOPS) Transportation Research Vehicle (TSRV)--a modified Boeing 737 Aircraft for advanced controls and displays research. These flight tests were conducted at NASA's Wallops Flight Center using the Microwave Landing System (MLS) installation on Runway 22. This report is primarily a collection of data plots of all performance variables recorded for the entire five flight tests. A description and source of the performance variables is included. Performance variables include inertial data, air data, automatic control commands, control servo positions, sensor data, DIALS guidance and control parameters, and Kalman filter data. This data illustrates low overshoot captures of the localizer for intercept angles of 20 deg, 30 deg, 40 deg, and 50 deg intercept angles, and low overshoot captures of the glideslope slope for 3 deg, 4.5 deg, and 5 deg glideslopes. Flare maneuvers were successfully performed from the various glideslope angles and good decrab maneuvers were performed in crosswinds of 6 knots. In 18 to 20 knot crosswind conditions rudder limiting occurred which caused lateral drifting although heading alignment was achieved.

NASA multipurpose airborne DIAL system and measurements of ozone and aerosol profiles. [DIfferential Absorption Lidar

NASA Technical Reports Server (NTRS)

Browell, E. V.; Carter, A. F.; Shipley, S. T.; Siviter, J. H., Jr.; Hall, W. M.; Allen, R. J.; Butler, C. F.; Mayo, M. N.

1983-01-01

The hardware, operational characteristics, data processing system, and applications of the NASA airborne differential absorption lidar (DIAL) system are described. DIAL functions by assessing the average gas concentration over a specified range interval by analyzing the difference in lidar backscatter signals for laser wavelengths tuned on and off of the molecular absorption line of a gas under investigation. The system comprises two frequency-doubled Nd:YAG lasers pumping two high conversion efficiency tunable dye lasers emitting pulses separated by 100 microsec or less. The return signals are digitized and stored on magnetic tape. The signal collector consists of photomultiplier tubes implanted in a cassegrain telescope. Flight tests of the system involved on-measurements at 285.95 nm and off-measurements at 299.40 nm, which yielded a differential cross section of 1.74 x 10 to the -16th sq cm. In situ measurements with another plane at a nominal altitude of 3.2 km for comparison purposes showed accuracy to within 10% in and above the boundary layer. The system is considered as a test apparatus for more developed versions to be flown on the Shuttle

User perceptions of the knowledge underpinning practice orientation dial (KUPOD) as a tool to enhance learning.

PubMed

Borlase, Jeanette; Abelson-Mitchell, Nadine

2008-01-01

The concern of academics and clinicians about the alleged dichotomy between theoretical concepts and the practice of nursing has been the catalyst for the development of a pocket-sized aid for nurses, known as the Knowledge Underpinning Practice Orientation Dial (KUPOD [N]/The Dial). A mixed method approach was used incorporating a questionnaire and a focus group of educators. The Dial was introduced, as part of a module, undertaken by a cohort of second-year Diploma in Nursing (Adult Branch) students. Twenty-eight students returned the questionnaire (response rate=85%). Results revealed that the Dial was easy to use in a variety of situations and locations. Respondents used the Dial within clinical and classroom settings and for self directed study. They reported that it was a practical and effective aid to learning, assisting in correlating theory and practice. It supported reflection and enhanced confidence in the clinical area, indicating that this economically produced tool helps to bridge the theory-practice gap. The Dial is now being introduced as a learning resource to a wider range of students.

Real Time Baseball Database

NASA Astrophysics Data System (ADS)

Fukue, Yasuhiro

The author describes the system outline, features and operations of "Nikkan Sports Realtime Basaball Database" which was developed and operated by Nikkan Sports Shimbun, K. K. The system enables to input numerical data of professional baseball games as they proceed simultaneously, and execute data updating at realtime, just-in-time. Other than serving as supporting tool for prepareing newspapers it is also available for broadcasting media, general users through NTT dial Q2 and others.

Digital Tone Ranging Modem.

DOT National Transportation Integrated Search

1976-05-01

This report describes a digital ranging modem implementation based on side-tone ranging concepts. The ranging technique implemented and tested in the DOT/TSC avionics laboratory has direct application to the AEROSAT surveillance system. The performan...

Detection probability of EBPSK-MODEM system

NASA Astrophysics Data System (ADS)

Yao, Yu; Wu, Lenan

2016-07-01

Since the impacting filter-based receiver is able to transform phase modulation into amplitude peak, a simple threshold decision can detect the Extend-Binary Phase Shift Keying (EBPSK) modulated ranging signal in noise environment. In this paper, an analysis of the EBPSK-MODEM system output gives the probability density function for EBPSK modulated signals plus noise. The equation of detection probability (pd) for fluctuating and non-fluctuating targets has been deduced. Also, a comparison of the pd for the EBPSK-MODEM system and pulse radar receiver is made, and some results are plotted. Moreover, the probability curves of such system with several modulation parameters are analysed. When modulation parameter is not smaller than 6, the detection performance of EBPSK-MODEM system is more excellent than traditional radar system. In addition to theoretical considerations, computer simulations are provided for illustrating the performance.

Real-time mobile phone dialing system based on SSVEP

NASA Astrophysics Data System (ADS)

Wang, Dongsheng; Kobayashi, Toshiki; Cui, Gaochao; Watabe, Daishi; Cao, Jianting

2017-03-01

Brain computer interface (BCI) systems based on the steady state visual evoked potential (SSVEP) provide higher information transfer rates and require shorter training time than BCI systems using other brain signals. It has been widely used in brain science, rehabilitation engineering, biomedical engineering and intelligent information processing. In this paper, we present a real-time mobile phone dialing system based on SSVEP, and it is more portable than other dialing system because the flashing dial interface is set on a small tablet. With this online BCI system, we can take advantage of this system based on SSVEP to identify the specific frequency on behalf of a number using canonical correlation analysis (CCA) method and dialed out successfully without using any physical movements such as finger tapping. This phone dialing system will be promising to help disable patients to improve the quality of lives.

82. VIEW OF AIRCONDITIONING CONTROLS LOCATED IN NORTHEAST CORNER OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

82. VIEW OF AIR-CONDITIONING CONTROLS LOCATED IN NORTHEAST CORNER OF SLC-3E CONTROL ROOM. DIAL ON RIGHT (EAST) PERPENDICULAR WALL IS DIMMER FOR ROOM LIGHTING. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Testing and performance analysis of a 650 Mbps QPPM modem for free-space laser communications

NASA Astrophysics Data System (ADS)

Mortensen, Dale J.

1994-08-01

The testing and performance of a prototype modem developed at NASA Lewis Research Center for high-speed free-space direct detection optical communications is described. The testing was performed under laboratory conditions using computer control with specially developed test equipment that simulates free-space link conditions. The modem employs quaternary pulse position modulation (QPPM) at 325 Megabits per second (Mbps) on two optical channels, which are multiplexed to transmit a single 650 Mbps data stream. The measured results indicate that the receiver's automatic gain control (AGC), phased-locked-loop slot clock recovery, digital symbol clock recovery, matched filtering, and maximum likelihood data recovery circuits were found to have only 1.5 dB combined implementation loss during bit-error-rate (BER) performance measurements. Pseudo random bit sequences and real-time high quality video sources were used to supply 650 Mbps and 325 Mbps data streams to the modem. Additional testing revealed that Doppler frequency shifting can be easily tracked by the receiver, that simulated pointing errors are readily compensated for by the AGC circuits, and that channel timing skew affects the BER performance in an expected manner. Overall, the needed technologies for a high-speed laser communications modem were demonstrated.

75 FR 17943 - Notice of Proposed Information Collection for Public Comment: Section 8 Random Digit Dialing Fair...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-08

... relatively fast and accurate way to estimate and update Section 8 Fair Market Rents (FMRs) in areas where... for surveying. HUD will conduct RDD surveys of up to 20 individual FMR areas in a year to test the...

47 CFR 95.1313 - Interconnection prohibited.

Code of Federal Regulations, 2010 CFR

2010-10-01

... points in the wireline or radio network of a public telephone company and persons served by multi-use... licensees or other authorized persons for transmitter control (including dial-up transmitter control circuits) or as an integral part of an authorized, private, internal system of communication or as an...

Managing Innovation.

ERIC Educational Resources Information Center

Mason, Marilyn Gell

1991-01-01

Describes one library's use of technological innovation to provide Associated Press updates over the library's 24-hour dial-up service during the Persian Gulf War. Suggests five rules for innovation: (1) develop a shared vision; (2) foster frequent, formal, and informal communication; (3) empower employees; (4) take limited risks; and (5) use, but…

National Weather Service Forecast Office Guam Home

Science.gov Websites

National Alerts Text Current Conditions Observations Satellite Hydrology River & Lake AHPS Radar Imagery AAFB (Guam) AAFB (Guam) Dial up CONUS Radar Forecasts Activity Planner Guam Public Marine Aviation ; Weather Topics: Local Alerts, Current Conditions, Radar, Satellite, Climate, W-GUM.Webmaster@noaa.gov

Synchronization techniques for all digital 16-ary QAM receivers operating over land mobile satellite links

NASA Technical Reports Server (NTRS)

Fines, P.; Aghvami, A. H.

1990-01-01

The performance of a low bit rate (64 Kb/s) all digital 16-ary Differentially Encoded Quadrature Amplitude Modulation (16-DEQAM) demodulator operating over a mobile satellite channel, is considered. The synchronization and detection techniques employed to overcome the Rician channel impairments, are described. The acquisition and steady state performance of this modem, are evaluated by computer simulation over AWGN and RICIAN channels. The results verify the suitability of the 16-DEQAM transmission over slowly faded and/or mildly faded channels.

QM/PSK Voice/Data Modem

DOT National Transportation Integrated Search

1976-03-01

Two Quadrature Modulation/Phase Shift Keyed (QM/PSK) Voice/Data Modem systems have been developed as part of the satellite communications hardware for advanced air traffic control systems. These systems consist of a modulator and demodulator unti whi...

Signal Analysis for Aerosat.

DOT National Transportation Integrated Search

1972-08-01

The report addresses signal design for the AEROSAT system. Candidate data and surveillance modems are analyzed for L-Band avionics. Detailed theoretical analyses are presented of the effects of the oceanic satellite-aircraft channel on data modem per...

Benthic microbial fuel cell as direct power source for an acoustic modem and seawater oxygen/temperature sensor system.

PubMed

Gong, Yanming; Radachowsky, Sage E; Wolf, Michael; Nielsen, Mark E; Girguis, Peter R; Reimers, Clare E

2011-06-01

Supported by the natural potential difference between anoxic sediment and oxic seawater, benthic microbial fuel cells (BMFCs) promise to be ideal power sources for certain low-power marine sensors and communication devices. In this study a chambered BMFC with a 0.25 m(2) footprint was used to power an acoustic modem interfaced with an oceanographic sensor that measures dissolved oxygen and temperature. The experiment was conducted in Yaquina Bay, Oregon over 50 days. Several improvements were made in the BMFC design and power management system based on lessons learned from earlier prototypes. The energy was harvested by a dynamic gain charge pump circuit that maintains a desired point on the BMFC's power curve and stores the energy in a 200 F supercapacitor. The system also used an ultralow power microcontroller and quartz clock to read the oxygen/temperature sensor hourly, store data with a time stamp, and perform daily polarizations. Data records were transmitted to the surface by the acoustic modem every 1-5 days after receiving an acoustic prompt from a surface hydrophone. After jump-starting energy production with supplemental macroalgae placed in the BMFC's anode chamber, the average power density of the BMFC adjusted to 44 mW/m(2) of seafloor area which is better than past demonstrations at this site. The highest power density was 158 mW/m(2), and the useful energy produced and stored was ≥ 1.7 times the energy required to operate the system.

Comparison of ozone profiles from DIAL, MLS, and chemical transport model simulations over Río Gallegos, Argentina, during the spring Antarctic vortex breakup, 2009

NASA Astrophysics Data System (ADS)

Sugita, Takafumi; Akiyoshi, Hideharu; Wolfram, Elián; Salvador, Jacobo; Ohyama, Hirofumi; Mizuno, Akira

2017-12-01

This study evaluates the agreement between ozone profiles derived from the ground-based differential absorption lidar (DIAL), satellite-borne Aura Microwave Limb Sounder (MLS), and 3-D chemical transport model (CTM) simulations such as the Model for Interdisciplinary Research on Climate (MIROC-CTM) over the Atmospheric Observatory of Southern Patagonia (Observatorio Atmosférico de la Patagonia Austral, OAPA; 51.6° S, 69.3° W) in Río Gallegos, Argentina, from September to November 2009. In this austral spring, measurements were performed in the vicinity of the polar vortex and inside it on some occasions; they revealed the variability in the potential vorticity (PV) of measured air masses. Comparisons between DIAL and MLS were performed between 6 and 100 hPa with 500 km and 24 h coincidence criteria. The results show a good agreement between DIAL and MLS with mean differences of ±0.1 ppmv (MLS - DIAL, n = 180) between 6 and 56 hPa. MIROC-CTM also agrees with DIAL, with mean differences of ±0.3 ppmv (MIROC-CTM - DIAL, n = 23) between 10 and 56 hPa. Both comparisons provide mean differences of 0.5 ppmv (MLS) to 0.8-0.9 ppmv (MIROC-CTM) at the 83-100 hPa levels. DIAL tends to underestimate ozone values at this lower altitude region. Between 6 and 8 hPa, the MIROC-CTM ozone value is 0.4-0.6 ppmv (5-8 %) smaller than those from DIAL. Applying the scaled PV (sPV) criterion for matching pairs in the DIAL-MLS comparison, the variability in the difference decreases 21-47 % between 10 and 56 hPa. However, the mean differences are small for all pressure levels, except 6 hPa. Because ground measurement sites in the Southern Hemisphere (SH) are very sparse at mid- to high latitudes, i.e., 35-60° S, the OAPA site is important for evaluating the bias and long-term stability of satellite instruments. The good performance of this DIAL system will be useful for such purposes in the future.

Local Area Networking Handbook

DTIC Science & Technology

1990-06-01

Number of dcvices IO’s-lOOO’s 10’s. I00Ys W0"s-10O’s supported Attachment cost S500-S50U) S40k-$ 56k S250-SIOOU C. LOCAL AREA NETWORKS Due to the...broadband cable by substituting RF modems for the conventional modems or line drivers. Then control may be imposed through conventional communications link...Ref. 11:p. 33] In a typical broadband bus configuration using FDM, channels are allocated dynamically, using frequency agile RF modems , rather than

Telemetric system for hydrology and water quality monitoring in watersheds of northern New Mexico, USA.

PubMed

Meyer, Michael L; Huey, Greg M

2006-05-01

This study utilized telemetric systems to sample microbes and pathogens in forest, burned forest, rangeland, and urban watersheds to assess surface water quality in northern New Mexico. Four sites included remote mountainous watersheds, prairie rangelands, and a small urban area. The telemetric system was linked to dataloggers with automated event monitoring equipment to monitor discharge, turbidity, electrical conductivity, water temperature, and rainfall during base flow and storm events. Site data stored in dataloggers was uploaded to one of three types of telemetry: 1) radio in rangeland and urban settings; 2) a conventional phone/modem system with a modem positioned at the urban/forest interface; and 3) a satellite system used in a remote mountainous burned forest watershed. The major variables affecting selection of each system were site access, distance, technology, and cost. The systems were compared based on operation and cost. Utilization of telecommunications systems in this varied geographic area facilitated the gathering of hydrologic and water quality data on a timely basis.

ITC/USA/'82; Proceedings of the International Telemetering Conference, San Diego, CA, September 28-30, 1982

NASA Astrophysics Data System (ADS)

The topics studied are related to customer-designed integrated circuits and silicon foundries, systems applications, recent developments in airborne telemetry hardware, optical communications, theoretical applications, stored data systems, digital communications-satellites and other systems, antenna systems and technology, the AF satellite control network, modems, telemetry standards, NASA Deep Space Network operations, and modems applicable to range telemetry and range data relay. Aspects of communication interoperability and transmission standards are considered along with subjects of magnetic tape rec/rep theory and technology, a satellite command and control panel, a computer automated ground station, STS communications, cryptography, RF systems, sensor unique data recovery techniques, software applications, multiplexer-demuliplexer, microprocessor applications, and communication relays. Attention is given to the U.S. Federal data encryption standard (DES), the impact of channel errors on data compression, the effect of premodulation filters on bit error rate performance, and power efficient optical communications for space applications. For individual items see A84-32402 to A84-32456

Baseband pulse shaping techniques for nonlinearly amplified pi/4-QPSK and QAM systems

NASA Technical Reports Server (NTRS)

Feher, Kamilo

1991-01-01

A new generation of multi-stage pi/4-shifted QPSK and of superposed quadrature-amplitude-modulated (SQAM) modulators-coherent demodulators (modems) and of continuous phase modulated (CPM)-gaussian premodulation filtered minimum-shift-keying (MGMSK) systems is proposed and studied. These modems will lead to bandwidth and power efficient satellite communications systems designs. As an illustrative application, a baseband processing technique pi/4-controlled transition PSK (pi/4-CTPSK) is described. To develop a cost and power efficient design strategy, we assume that nonlinear, fully saturated high power amplifiers (HPA) are utilized in the satellite earth station transmitter and in the satellite transponder. Modem structures which could lead to application specific integrated circuit (ASIC) satellite on-board processing universal modem applications are also considered. Multistate GMSK (i.e., MGMSK) signal generation methods by means of two or more RF combined nonlinearly amplified SQAM modems and by one multistate (in-phase and quadrature-baseband premodulation filtered-superposed) SQAM architecture and one RF nonlinear amplifier are studied. During the SQAM modem development phase we investigate the potential system advantages of the pi/4-shifted logic. The bandwidth efficiency of the proposed multistate GMSK and baseband filtered PAM-FM modulator (a new class in the CPM family) will be significantly higher than that of conventional G-MSK systems. To optimize the practical P(sub e) = f((E sub b)/(N sub o)) performance we consider improved coherent demodulation MGMSK structures such as deviated-frequency locking coherent demodulators. For relative low bit rate SATCOM applications, e.g., bit rates less than 300 kb/s, phase noise tracking cancellation (for fixed site earth station) and phase noise cancellation as well as Doppler compensation (for satellite to mobile earth station) applications may be required. We study digital channel sounding methods which could cancel the phase noise-caused degradations of CPM and GMSK modems.

DialBetics: A Novel Smartphone-based Self-management Support System for Type 2 Diabetes Patients.

PubMed

Waki, Kayo; Fujita, Hideo; Uchimura, Yuji; Omae, Koji; Aramaki, Eiji; Kato, Shigeko; Lee, Hanae; Kobayashi, Haruka; Kadowaki, Takashi; Ohe, Kazuhiko

2014-03-01

Numerous diabetes-management systems and programs for improving glycemic control to meet guideline targets have been proposed, using IT technology. But all of them allow only limited-or no-real-time interaction between patients and the system in terms of system response to patient input; few studies have effectively assessed the systems' usability and feasibility to determine how well patients understand and can adopt the technology involved. DialBetics is composed of 4 modules: (1) data transmission module, (2) evaluation module, (3) communication module, and (4) dietary evaluation module. A 3-month randomized study was designed to assess the safety and usability of a remote health-data monitoring system, and especially its impact on modifying patient lifestyles to improve diabetes self-management and, thus, clinical outcomes. Fifty-four type 2 diabetes patients were randomly divided into 2 groups, 27 in the DialBetics group and 27 in the non-DialBetics control group. HbA1c and fasting blood sugar (FBS) values declined significantly in the DialBetics group: HbA1c decreased an average of 0.4% (from 7.1 ± 1.0% to 6.7 ± 0.7%) compared with an average increase of 0.1% in the non-DialBetics group (from 7.0 ± 0.9% to 7.1 ± 1.1%) (P = .015); The DialBetics group FBS decreased an average of 5.5 mg/dl compared with a non-DialBetics group average increase of 16.9 mg/dl (P = .019). BMI improvement-although not statistically significant because of the small sample size-was greater in the DialBetics group. DialBetics was shown to be a feasible and an effective tool for improving HbA1c by providing patients with real-time support based on their measurements and inputs. © 2014 Diabetes Technology Society.

Analog Ranging Modem Code Processor and Generator

DOT National Transportation Integrated Search

1974-05-01

The report details technical development efforts to implement an analog ranging modem using recently developed linear integrated circuits where possible. The breadboard hardware is capable of acquiring frequency and phase of a weak signal in a high n...

Burst Mode ASIC-Based Modem

NASA Technical Reports Server (NTRS)

1997-01-01

The NASA Lewis Research Center is sponsoring the Advanced Communication Technology Insertion (ACTION) for Commercial Space Applications program. The goal of the program is to expedite the development of new technology with a clear path towards productization and enhancing the competitiveness of U.S. manufacturers. The industry has made significant investment in developing ASIC-based modem technology for continuous-mode applications and has made investigations into East, reliable acquisition of burst-mode digital communication signals. With rapid advances in analog and digital communications ICs, it is expected that more functions will be integrated onto these parts in the near future. In addition custom ASIC's can also be developed to address the areas not covered by the other IC's. Using the commercial chips and custom ASIC's, lower-cost, compact, reliable, and high-performance modems can be built for demanding satellite communication application. This report outlines a frequency-hop burst modem design based on commercially available chips.

Advanced technology satellite demodulator development

NASA Technical Reports Server (NTRS)

Ames, Stephen A.

1989-01-01

Ford Aerospace has developed a proof-of-concept satellite 8 phase shift keying (PSK) modulation and coding system operating in the Time Division Multiple Access (TDMA) mode at a data range of 200 Mbps using rate 5/6 forward error correction coding. The 80 Msps 8 PSK modem was developed in a mostly digital form and is amenable to an ASIC realization in the next phase of development. The codec was developed as a paper design only. The power efficiency goal was to be within 2 dB of theoretical at a bit error rate (BER) of 5x10(exp 7) while the measured implementation loss was 4.5 dB. The bandwidth efficiency goal was 2 bits/sec/Hz while the realized bandwidth efficiency was 1.8 bits/sec/Hz. The burst format used a preamble of only 40 8 PSK symbol times including 32 symbols of all zeros and an eight symbol unique word. The modem and associated special test equipment (STE) were fabricated mostly on a specially designed stitch-weld board although a few of the highest rate circuits were built on printed circuit cards. All the digital circuits were ECL to support the clock rates of from 80 MHz to 360 MHz. The transmitter and receiver matched filters were square-root Nyquist bandpass filters realized at the 3.37 GHz i.f. The modem operated as a coherent system although no analog phase locked (PLL) loop was employed. Within the budgetary constraints of the program, the approach to the demodulator has been proven and is eligible to proceed to the next phase of development of a satellite demodulator engineering model. This would entail the development of an ASIC version of the digital portion of the demodulator, and MMIC version of the quadrature detector, and SAW Nyquist filters to realize the bandwidth efficiency.

76 FR 60820 - North American Electric Reliability Corporation; Notice of Technical Conference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-30

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RD10-8-000] North American Electric Reliability Corporation; Notice of Technical Conference Take notice that the Federal Energy... Conference will explore the risks of leaving dial-up intelligent electronic devices that are part of the Bulk...

Securing TCP/IP and Dial-up Access to Administrative Data.

ERIC Educational Resources Information Center

Conrad, L. Dean

1992-01-01

This article describes Arizona State University's solution to security risk inherent in general access systems such as TCP/IP (Transmission Control Protocol/INTERNET Protocol). Advantages and disadvantages of various options are compared, and the process of selecting a log-on authentication approach involving generation of a different password at…

Fire Effects Information System: New engine, remodeled interior, added options

Treesearch

Jane Kapler Smith

2010-01-01

Some of today's firefighters weren't even born when the Fire Effects Information System (FEIS) (Web site ) "hit the streets" in 1986. Managers might remember using a dial-up connection in the early 1990s to access information on biology, ecology, and fire offered by FEIS.

Interactive Video Program. Final Report and Recommendations.

ERIC Educational Resources Information Center

Midwestern Higher Education Commission, Minneapolis, MN.

This report presents recommendations on interactive video transmission standards, equipment, room designs, and service plans for member institutions of the Midwestern Higher Education Commission (MHEC) and reviews MHEC's efforts to find and contract for such services with vendors. The report describes the MHEC objective of establishing a dial-up,…

78 FR 38227 - Connect America Fund

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-26

... different per- location support amounts based on the existing level of Internet access ($550 for homes with low-speed Internet access and $775, as in the first round, for homes with only dial-up access), and... Internet access. We adopt a process for challenges to the eligibility of specific areas where price cap...

Putting the Medical Library Online: Electronic Bulletin Boards. . . and Beyond.

ERIC Educational Resources Information Center

Kittle, Paul W.

1985-01-01

Describes use of microcomputers with system called "TBBS" ("The Bread Board System") at Loma Linda University Medical Center to allow users enhanced services from home, whether library facilities are open or not. Flexibility and security, dialing into medical library, and suggestions for setting up similar computerized…

The Many Faces of the Economic Bulletin Board.

ERIC Educational Resources Information Center

Boettcher, Jennifer

1996-01-01

The Economic Bulletin Board (EBB), a one-stop site for economic statistics and government-sponsored business information, can be accessed on the World Wide Web, gopher, telnet, file transfer protocol, dial-up, and fax. Each access method has advantages and disadvantages related to connections, pricing, depth of access, retrieval, and system…

Comparison of ozone profiles obtained with NIES DIAL and SAGE II measurements

NASA Technical Reports Server (NTRS)

Nakane, Hideaki; Sasano, Yasuhiro; Hayashida-Amano, Sachiko; Sugimoto, Nobuo; Matsui, Ichiro; Minato, Atsushi; Mccormick, M. P.

1993-01-01

Ozone profiles obtained with the Differential Absorption Lidar (DIAL) system at the National Institute for Environmental Studies (NIES) (Tsukuba, Japan) were compared with data provided by the satellite sensor SAGE II. The SAGE II data were selected based on criteria of spatial and temporal differences between the DIAL and the SAGE II measurements: five degrees in latitude and 15 degrees in longitude, within a latitudinal band from 31 deg to 41 deg N, and within one, three and five days after or before the DIAL measurements. Results show very good agreement for the individual and the zonal-mean profiles. The average mean difference between the DIAL and the SAGE II measurements over the altitudes 15-50 km was about 10 percent.

An update on 'dose calibrator' settings for nuclides used in nuclear medicine.

PubMed

Bergeron, Denis E; Cessna, Jeffrey T

2018-06-01

Most clinical measurements of radioactivity, whether for therapeutic or imaging nuclides, rely on commercial re-entrant ionization chambers ('dose calibrators'). The National Institute of Standards and Technology (NIST) maintains a battery of representative calibrators and works to link calibration settings ('dial settings') to primary radioactivity standards. Here, we provide a summary of NIST-determined dial settings for 22 radionuclides. We collected previously published dial settings and determined some new ones using either the calibration curve method or the dialing-in approach. The dial settings with their uncertainties are collected in a comprehensive table. In general, current manufacturer-provided calibration settings give activities that agree with National Institute of Standards and Technology standards to within a few percent.

Snails, stable iostopes, and southwestern desert paleoclimates

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

Sharpe, S.E.; Whelan, J.F.; Forester, R.M.

1995-09-01

Modern and fossil molluscs (snails) occur in many localities in and semi-arid regions throughout the desert southwest. Live terrestrial snails are found under rocks and in forest litter and aquatic taxa inhabit springs, seeps, and/or wetlands. Molluscs uptake local water during their growing season (spring and summer) and incorporate its delta 180 signature into their shells. Preliminary 180 analysis of modem shells from the southern Great Basin indicates that the shells probably reflect meteoric water 180 values during the growing season. This provides a way to estimate the delta 180 value of precipitation and, thereby, the source of the moisture-bearingmore » air masses. Significant 180 variability in shells analyzed include geographic location, elevation, taxonomy, and habitat (terrestrial, spring, or wetland). We found a rough inverse correlation with elevation in modem shells from the Spring Range in southern Nevada. The delta 180 values of modem and fossil shells are also very different; modem values in this location are much higher than those from nearby late Pleistocene-age molluscs suggesting that the Pleistocene summers were variously colder and wetter than today or less evaporative (more humid). Assuming shell material directly reflects the 180 of the growing-season environment, comparison of modem and fossil shell delta 180 values can potentially identify changes in air-mass moisture sources and can help to define seasonal precipitation change through time. Comprehension and quantification of community and isotopic variability in modem gastropods is required to create probabilistic valid transfer functions with fossil materials. Valid inferences about past environmental conditions can then be established with known confidence limits.« less

Preparing the Plate Boundary Observatory GNSS Network for the Future

NASA Astrophysics Data System (ADS)

Austin, K. E.; Walls, C. P.; Dittman, T.; Mann, D.; Boyce, E. S.; Basset, A.; Woolace, A. C.; Turner, R.; Lawrence, S.; Rhoades, S.; Pyatt, C.; Willoughby, H.; Feaux, K.; Mattioli, G. S.

2017-12-01

The EarthScope Plate Boundary Observatory (PBO) GNSS network, funded by the NSF and operated by UNAVCO, is comprised of 1100 permanent GPS and GNSS stations spanning three principal tectonic regimes and is administered by distinct management. The GPS-only network was initially designed for daily data file downloads primarily for tectonic analysis. This low data volume requirement and circa-2004 IP-based cellular/VSat modems provided significant freedom for station placement and enabled science-targeted installation of stations in some of the most remote and geologically interesting areas. Community requests for high-rate data downloads for GNSS seismology, airborne LiDAR surveys, meteorological/GNSS/seismic real-time data flow and other demands, however, require significantly increased bandwidth beyond the 5-20 kB/s transfer rates that were needed as part of the original design. Since the close of construction in September 2008, PBO enhancements have been implemented through additional funding by the NSF (ARRA/Cascadia), NOAA, and NASA and in collaboration with stakeholders such as Caltrans, ODOT, Scripps, and the USGS. Today, only 18 of the original cell modems remain, with 601 upgraded cell modems providing 3G/4G/LTE data communications that support transfer rates ranging from 80-400 kB/s. Radio network expansion and upgrades continue to harden communications using both 2.4 GHz and 5.8 GHz radios. 78 VSAT and 5 manual download sites remain. PBO-wide the network capabilities for 1 Hz & 5 Hz downloads or low latency 1 Hz streaming are 85%, 80% and 65% of PBO stations, respectively, with 708 active 1 Hz streams. Vaisala meteorological instruments are located at 140 sites most of which stream GPS/Met data in real time. GPS-only receivers are being replaced with GNSS receivers and antennas. Today, there are 279 stations in the PBO network with either GLONASS enabled Trimble NetR9 or full GNSS constellation Septentrio PolaRx5 receivers. Just as the scale and geographical density of the PBO project has opened up new and unexpected avenues for geophysical research across disciplines (e.g. atmosphere, meteorology, snow pack, tides, vegetation growth, drought monitoring, etc.), the coming decade under the NGEO banner will undoubtedly present new opportunities as the network continues to be modernized.

76 FR 30196 - Notice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-24

... Access Points, Cable Modems, IP Phones, and Products Containing Same, DN 2807; the Commission is..., wireless, access points, cable modems, IP phones, and products containing same. The complaint names as...

Implementation and Testing of the JANUS Standard with SSC Pacific’s Software-Defined Acoustic Modem

DTIC Science & Technology

2017-10-01

Communications Outpost (FDECO) Innovative Naval Prototype (INP) Program by the Advanced Photonic Technologies Branch (Code 55360), Space and Naval Warfare...underwater acoustic communication operations with NATO and non-NATO military and civilian maritime assets. iv ACRONYMS SPAWAR Space and Naval Warfare...the center frequency [1]. The ease of implementation and proven robustness in harsh underwater acoustic communication channels paved the way for

Astronaut James Newman works with computers and GPS

NASA Image and Video Library

1993-09-20

STS051-16-028 (12-22 Sept 1993) --- On Discovery's middeck, astronaut James H. Newman, mission specialist, works with an array of computers, including one devoted to Global Positioning System (GPS) operations, a general portable onboard computer displaying a tracking map, a portable audio data modem and another payload and general support computer. Newman was joined by four other NASA astronauts for almost ten full days in space.

New Trends in Two-Way Time and Frequency Transfer via Satellite

DTIC Science & Technology

1999-12-01

Recent developments performed with SATRE two-way time transfer ( TWSTFT ) modems resulted in significant performance upgrades and operational...improvements of the TWSTFT method These are aimed to reduce : manpower effort and to provide reliable, real-time data via a centralized monitoring and...collection have been used throughout the experiment INTRODUCTION Two-Way Time and Frequency Transfer via Satellite ( TWSTFT ) is a well established method to

Delineating Grazing: Observations of Remote Control Use.

ERIC Educational Resources Information Center

Eastman, Susan Tyler; Newton, Gregory D.

1995-01-01

States that contrary to previous reports of "grazing," most viewers only used their remote control devices (RCDs) once or twice every half hour. Claims that the dominant RCD operation was direct channel punching, as opposed to dial turning. Concludes that most RCD activity did not take place during a program, thus voiding industry…

A TMS320-based modem for the aeronautical-satellite core data service

NASA Astrophysics Data System (ADS)

Moher, Michael L.; Lodge, John H.

The International Civil Aviation Organization (ICAO) Future Air Navigation Systems (FANS) committee, the Airlines Electronics Engineering Committee (AEEC), and Inmarsat have been developing standards for an aeronautical satellite communications service. These standards encompass a satellite communications system architecture to provide comprehensive aeronautical communications services. Incorporated into the architecture is a core service capability, providing only low rate data communications, which all service providers and all aircraft earth terminals are required to support. In this paper an implementation of the physical layer of this standard for the low data rate core service is described. This is a completely digital modem (up to a low intermediate frequency). The implementation uses a single TMS320C25 chip for the transmit baseband functions of scrambling, encoding, interleaving, block formatting and modulation. The receiver baseband unit uses a dual processor configuration to implement the functions of demodulation, synchronization, de-interleaving, decoding and de-scrambling. The hardware requirements, the software structure and the algorithms of this implementation are described.

The Internet: How Fast Can You Download?

ERIC Educational Resources Information Center

Shearer, Ron

1997-01-01

Discusses faster modems for downloading information from the Internet that may become available through cable or telephone industries. Topics include ADSL (Asymmetric Digital Subscriber Line) modems; Direct PC--downloading satellite transmissions; Land Multichannel Distribution System (LMDS)--a wireless communication device; and Internet…

Testing and performance analysis of a 650-Mbps quaternary pulse position modulation (QPPM) modem for free-space laser communications

NASA Astrophysics Data System (ADS)

Mortensen, Dale J.

1995-04-01

The testing and performance of a prototype modem developed at NASA Lewis Research Center for high-speed free-space direct detection optical communications is described. The testing was performed under laboratory conditions using computer control with specially developed test equipment that simulates free-space link conditions. The modem employs quaternary pulse position modulation at 325 Megabits per second (Mbps) on two optical channels, which are multiplexed to transmit a single 650 Mbps data stream. The measured results indicate that the receiver's automatic gain control (AGC), phased-locked-loop slot clock recovery, digital symbol clock recovery, matched filtering, and maximum likelihood data recovery circuits were found to have only 1.5 dB combined implementation loss during bit-error-rate (BER) performance measurements. Pseudo random bit sequences and real-time high quality video sources were used to supply 650 Mbps and 325 Mbps data streams to the modem. Additional testing revealed that Doppler frequency shifting can be easily tracked by the receiver, that simulated pointing errors are readily compensated for by the AGC circuits, and that channel timing skew affects the BER performance in an expected manner. Overall, the needed technologies for a high-speed laser communications modem were demonstrated.

Quantitative analysis of Ostracoda and water masses around Japan: Application to Pliocene and Pleistocene paleoceanography

USGS Publications Warehouse

Ikeya, Noriyuki; Cronin, Thomas M.

1993-01-01

An ostracode data base consisting of 273 samples from coretops and comprising 226 species was developed for the seas around the Japanese Islands to determine zoogeographic patterns and for application to Pliocene and Pleistocene paleoceanography in the area. Quantitative analyses of the 59 most common taxa between 0 and 300m water depth indicate that ostracode associations are controlled by the main oceanic water masses around Japan and that bottom water temperature is a key factor influencing species distributions. Ostracodes from the following water masses were studied: warm Kuroshio Current, Tsushima Current (Tsugaru Current and Soya Current), Japan Sea intermediate water, Japan Sea proper water and cold Oyashio Current. In order to apply the modem coretop data base to fossil ostracode assemblages, the modem analog technique (MAT) using a squared chord distance (SCD) measure of dissimilarity was tested as a means of comparing fossil and modem assemblages. SCD values of 0.25 or less adequately identify modem analogs from the coretop data set at the local ecological level (i.e. within the same modern bay), while values of 0.25-0.5 identify modem analogs at the level of the zoogeographic province. The MAT method was tested against 3 Pliocene and 11 Pleistocene formations in Japan to examine the use of the MAT in paleoceanographic reconstruction.

DIAL Measurements of Free-Tropospheric Ozone Profiles in Huntsville, AL

NASA Technical Reports Server (NTRS)

Kuang, Shi; Burris, John; Newchurch, Michael J.; Johnson, Steve

2007-01-01

A tropospheric ozone Differential Absorption Lidar (DIAL) system, developed jointly by NASA and the University of Alabama at Huntsville (UAH), measures free-tropospheric ozone profiles between 4-10 km. Located at 192 meters altitude in the Regional Atmospheric Profiling Laboratory for Discovery (RAPCD) on the UAH campus in Huntsville, AL, USA, this tropospheric ozone lidar operates under both daytime and nighttime conditions. Frequent coincident ozonesonde flights and theoretical calculations provide evidence to indicate the retrieval accuracy ranges from better than 8% at 4km to 40%-60% at 10 kin with 750-m vertical resolution and 30-minute integration. With anticipated improvements to allow retrievals at both higher and lower altitudes, this ozone lidar, along with co-located aerosol and Doppler Wind Lidars, will provide a unique 18 dataset for investigations of PBL and free-tropospheric chemical and dynamic processes.

Advanced Detector and Waveform Digitizer for Water Vapor DIAL Systems

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

1998-01-01

Measurement of atmospheric water vapor has become a major requirement for understanding moist-air processes. Differential absorption lidar (DIAL) is a technique best suited for the measurement of atmospheric water vapor. NASA Langley Research Center is continually developing improved DIAL systems. One aspect of current development is focused on the enhancement of a DIAL receiver by applying state-of-the-art technology in building a new compact detection system that will be placed directly on the DIAL receiver telescope. The newly developed detection system has the capability of being digitally interfaced with a simple personal computer, using a discrete input/output interface. This has the potential of transmitting digital data over relatively long distances instead of analog signals, which greatly reduces measurement noise. In this paper, we discuss some results from the new compact water vapor DIAL detection system which includes a silicon based avalanche photodiode (APD) detector, a 14-bit, 10-MHz waveform digitizer, a microcontroller and other auxiliary electronics. All of which are contained on a small printed-circuit-board. This will significantly reduce the weight and volume over the current CAMAC system and eventually will be used in a water vapor DIAL system on an unpiloted atmospheric vehicle (UAV) aircraft, or alternatively on an orbiting spacecraft.

Detection and monitoring of pollutant sources with Lidar/Dial techniques

NASA Astrophysics Data System (ADS)

Gaudio, P.; Gelfusa, M.; Malizia, A.; Parracino, S.; Richetta, M.; De Leo, L.; Perrimezzi, C.; Bellecci, C.

2015-11-01

It's well known that air pollution due to anthropogenic sources can have adverse effects on humans and the ecosystem. Therefore, in the last years, surveying large regions of the atmosphere in an automatic way has become a strategic objective of various public health organizations for early detection of pollutant sources in urban and industrial areas. The Lidar and Dial techniques have become well established laser based methods for the remote sensing of the atmosphere. They are often implemented to probe almost any level of the atmosphere and to acquire information to validate theoretical models about different topics of atmospheric physics. They can also be used for environment surveying by monitoring particles, aerosols and molecules. The aim of the present work is to demonstrate the potential of these methods to detect pollutants emitted from local sources (such as particulate and/or chemical compounds) and to evaluate their concentration. This is exemplified with the help of experimental data acquired in an industrial area in the south of Italy by mean of experimental campaign by use of pollutants simulated source. For this purpose, two mobile systems Lidar and Dial have been developed by the authors. In this paper there will be presented the operating principles of the system and the results of the experimental campaign.

Development and operation of a real-time data acquisition system for the NASA, Langley Research Center Differential Absorption Lidar

NASA Technical Reports Server (NTRS)

Butler, C.; Kindle, E. C.

1984-01-01

The capabilities of the DIAL data acquisition system (DAS) for the remote measurement of atmospheric trace gas concentrations from ground and aircraft platforms were extended through the purchase and integration of other hardware and the implementation of improved software. An operational manual for the current system is presented. Hardware and peripheral device registers are outlined only as an aid in debugging any DAS problems which may arise.

77 FR 21996 - Certain Equipment for Communications Networks, Including Switches, Routers, Gateways, Bridges...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-12

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-778] Certain Equipment for Communications Networks, Including Switches, Routers, Gateways, Bridges, Wireless Access Points, Cable Modems, IP Phones... networks, including switches, routers, gateways, bridges, wireless access points, cable modems, IP phones...

Impact of satellite aeronautical channel on modem specifications

DOT National Transportation Integrated Search

1974-03-01

The report analyzes the effects of surface-scattered multipath on the performance of ranging and data modems such as might be used on the aircraft-satellite channel of an air-traffic control system. An exact analysis is carried out on the effects of ...

Prototype part task trainer: A remote manipulator system simulator

NASA Technical Reports Server (NTRS)

Shores, David

1989-01-01

The Part Task Trainer program (PTT) is a kinematic simulation of the Remote Manipulator System (RMS) for the orbiter. The purpose of the PTT is to supply a low cost man-in-the-loop simulator, allowing the student to learn operational procedures which then can be used in the more expensive full scale simulators. PTT will allow the crew members to work on their arm operation skills without the need for other people running the simulation. The controlling algorithms for the arm were coded out of the Functional Subsystem Requirements Document to ensure realistic operation of the simulation. Relying on the hardware of the workstation to provide fast refresh rates for full shaded images allows the simulation to be run on small low cost stand alone work stations, removing the need to be tied into a multi-million dollar computer for the simulation. PTT will allow the student to make errors which in full scale mock up simulators might cause failures or damage hardware. On the screen the user is shown a graphical representation of the RMS control panel in the aft cockpit of the orbiter, along with a main view window and up to six trunion and guide windows. The dials drawn on the panel may be turned to select the desired mode of operation. The inputs controlling the arm are read from a chair with a Translational Hand Controller (THC) and a Rotational Hand Controller (RHC) attached to it.

Rater agreement reliability of the dial test in the ACL-deficient knee.

PubMed

Slichter, Malou E; Wolterbeek, Nienke; Auw Yang, K Gie; Zijl, Jacco A C; Piscaer, Tom M

2018-06-14

Posterolateral rotatory instability (PLRI) of the knee can easily be missed, because attention is paid to injury of the cruciate ligaments. If left untreated this clinical instability may persist after reconstruction of the cruciate ligaments and may put the graft at risk of failure. Even though the dial test is widely used to diagnose PLRI, no validity and reliability studies of the manual dial test are yet performed in patients. This study focuses on the reliability of the manual dial test by determining the rater agreement. Two independent examiners performed the dial test in knees of 52 patients after knee distorsion with a suspicion on ACL rupture. The dial test was performed in prone position in 30°, 60° and 90° of flexion of the knees. ≥10° side-to-side difference was considered a positive dial test. For quantification of the amount of rotation in degrees, a measuring device was used with a standardized 6 Nm force, using a digital torque adapter on a booth. The intra-rater, inter-rater and rater-device agreement were determined by calculating kappa (κ) for the dial test. A positive dial test was found in 21.2% and 18.0% of the patients as assessed by a blinded examiner and orthopaedic surgeon respectively. Fair inter-rater agreement was found in 30° of flexion, κ F  = 0.29 (95% CI: 0.01 to 0.56), p = 0.044 and 90° of flexion, κ F  = 0.38 (95% CI: 0.10 to 0.66), p = 0.007. Almost perfect rater-device agreement was found in 30° of flexion, κ C  = 0.84 (95% CI: 0.52 to 1.15), p < 0.001. Moderate rater-device agreement was found in 30° and 90° combined, κ C  = 0.50 (95% CI: 0.13 to 0.86), p = 0.008. No significant intra-rater agreement was found. Rater agreement reliability of the manual dial test is questionable. It has a fair inter-rater agreement in 30° and 90° of flexion.

Meeting the Challenges of Regional Security

DTIC Science & Technology

1994-02-01

targets over time, assessing strike damage, and, of course, developing up-to- date maps of crucial urban and industrial areas. Coupled with modem digital ...of huge diverse data bases is key to dissecting criminal infrastructures, and identifying relevant regional and global linkages. New digital processing...cities). They can aid in reaction force planning and training. One 10-inch optical disc can easily store 25 (and display at any scale with 4- digit

Monitoring fugitive methane and natural gas emissions, validation of measurement techniques.

NASA Astrophysics Data System (ADS)

Robinson, Rod; Innocenti, Fabrizio; Gardiner, Tom; Helmore, Jon; Finlayson, Andrew; Connor, Andy

2017-04-01

The detection and quantification of fugitive and diffuse methane emissions has become an increasing priority in recent years. As the requirements for routine measurement to support industry initiatives increase there is a growing requirement to assess and validate the performance of fugitive emission measurement technologies. For reported emissions traceability and comparability of measurements is important. This talk will present recent work addressing these needs. Differential Absorption Lidar (DIAL) is a laser based remote sensing technology, able to map the concentration of gases in the atmosphere and determine emission fluxes for fugitive emissions. A description of the technique and its application for determining fugitive emissions of methane from oil and gas operations and waste management sites will be given. As DIAL has gained acceptance as a powerful tool for the measurement and quantification of fugitive emissions, and given the rich data it produces, it is being increasingly used to assess and validate other measurement approaches. In addition, to support the validation of technologies, we have developed a portable controlled release facility able to simulate the emissions from area sources. This has been used to assess and validate techniques which are used to monitor emissions. The development and capabilities of the controlled release facility will be described. This talk will report on recent studies using DIAL and the controlled release facility to validate fugitive emission measurement techniques. This includes side by side comparisons of two DIAL systems, the application of both the DIAL technique and the controlled release facility in a major study carried out in 2015 by South Coast Air Quality Management District (SCAQMD) in which a number of optical techniques were assessed and the development of a prototype method validation approach for techniques used to measure methane emissions from shale gas sites. In conclusion the talk will provide an update on the current status in the development of a European Standard for the measurement of fugitive emissions of VOCs and the use of validation data in the standardisation process and discuss the application of this to methane measurement.

46 CFR 520.9 - Access to tariffs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... networks (“PSTN”); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (b) Dial-up...) Internet connection. (1) This connection option requires that systems provide: (i) A universal resource locator (“URL”) Internet address (e.g., http://www.tariffsrus.com or http://1.2.3.4); and/or (ii) A URL...

46 CFR 520.9 - Access to tariffs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... networks (“PSTN”); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (b) Dial-up...) Internet connection. (1) This connection option requires that systems provide: (i) A universal resource locator (“URL”) Internet address (e.g., http://www.tariffsrus.com or http://1.2.3.4); and/or (ii) A URL...

46 CFR 520.9 - Access to tariffs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... networks (“PSTN”); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (b) Dial-up...) Internet connection. (1) This connection option requires that systems provide: (i) A universal resource locator (“URL”) Internet address (e.g., http://www.tariffsrus.com or http://1.2.3.4); and/or (ii) A URL...

46 CFR 520.9 - Access to tariffs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... networks (“PSTN”); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (b) Dial-up...) Internet connection. (1) This connection option requires that systems provide: (i) A universal resource locator (“URL”) Internet address (e.g., http://www.tariffsrus.com or http://1.2.3.4); and/or (ii) A URL...

46 CFR 520.9 - Access to tariffs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... networks (“PSTN”); or (2) The Internet (Web) by: (i) Web browser; or (ii) Telnet session. (b) Dial-up...) Internet connection. (1) This connection option requires that systems provide: (i) A universal resource locator (“URL”) Internet address (e.g., http://www.tariffsrus.com or http://1.2.3.4); and/or (ii) A URL...

Calculus, Radio Dials and the Straight-Line Frequency Variable Capacitor

ERIC Educational Resources Information Center

Boyadzhiev, Khristo N.

2010-01-01

Most often radio dials of analogue radios are not uniformly graded; the frequencies are cramped on the left side or on the right side. This makes tuning more difficult. Why are dials made this way? We shall see here that simple calculus can help understand this problem and solve it. (Contains 7 figures.)

DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2 lasers

NASA Technical Reports Server (NTRS)

Brockman, P.; Hess, R. V.; Staton, L. D.; Bair, C. H.

1980-01-01

Atmospheric trace constituent measurements with higher vertical resolution than attainable with passive radiometers are discussed. Infrared differential absorption lidar (DIAL), which depends on Mie scattering from aerosols, has special advantages for tropospheric and lower stratospheric applications and has great potential importance for measurements from shuttle and aircraft. Differential absorption lidar data reduction involves comparing large amplitude signals which have small differences. The accuracy of the trace constituent concentration inferred from DIAL measurements depends strongly on the errors in determining the amplitude of the signals. Thus, the commonly used SNR expression (signal divided by noise in the absence of signal) is not adequate to describe DIAL measurement accuracy and must be replaced by an expression which includes the random coherent (speckle) noise within the signal. A comprehensive DIAL computer algorithm is modified to include heterodyne detection and speckle noise. Examples for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system are given.

Solid-state Raman frequency converters for CO2-DIAL systems at 1.6 μm

NASA Astrophysics Data System (ADS)

Rhee, Hanjo; Lisinetskii, Victor; Kaminskii, Alexander A.; Eichler, Hans-Joachim

2009-09-01

Measurement of the three-dimensional distribution of atmospheric trace gases, especially CO2, is an important factor to improve the accuracy of climate models and to understand the global effects of the greenhouse effect. This can be achieved by differential absorption Lidar (DIAL). The absorption spectrum of CO2 features several suitable absorption lines for a ground-based or air-borne DIAL system working at wavelengths between 1.57 μm and 1.61 μm. An appropriate laser transmitter must emit laser pulses with pulse energies of more than 10 mJ and pulse duration in the nanosecond range. For high spectral purity the bandwidth is required to be less than 60 MHz. OPOs and Er-doped solid-state lasers emit around 1.6 μm, but we describe here alternatively Nd:YAG and Nd:glass laser systems with Raman converters. The use of stimulated Raman scattering in crystalline and ceramic materials is a possibility to shift the wavelength of existing lasers depending on the size of the Raman shift. After the investigation of a large number of Raman-active materials some of them could be identified as promising candidates for the conversion of typical Nd:YAG emission wavelengths, including LiNH2C6H4SO3•H2O, Ba(NO3)2, Li2SO4•H2O, Y(HCOO)3•2H2O, β-BBO and diamond. Our experiments with Ba(NO3)2 showed that the choice of the material should not be restricted to those with an adequate first order Stokes Raman line position, but also second or third order Raman shift should be considered. Development of Raman frequency converters for high pulse energies concentrates on linear and folded resonator designs and seeded Raman amplifiers using the Raman material as a direct amplifier. With Ba(NO3)2 pulse energy up to 116 mJ and 42 % quantum efficiency at the third Stokes wavelength with 1599 nm has been demonstrated. High power operation at 5 W with compensation of thermal lensing was achieved.

Programmable rate modem utilizing digital signal processing techniques

NASA Technical Reports Server (NTRS)

Bunya, George K.; Wallace, Robert L.

1989-01-01

The engineering development study to follow was written to address the need for a Programmable Rate Digital Satellite Modem capable of supporting both burst and continuous transmission modes with either binary phase shift keying (BPSK) or quadrature phase shift keying (QPSK) modulation. The preferred implementation technique is an all digital one which utilizes as much digital signal processing (DSP) as possible. Here design tradeoffs in each portion of the modulator and demodulator subsystem are outlined, and viable circuit approaches which are easily repeatable, have low implementation losses and have low production costs are identified. The research involved for this study was divided into nine technical papers, each addressing a significant region of concern in a variable rate modem design. Trivial portions and basic support logic designs surrounding the nine major modem blocks were omitted. In brief, the nine topic areas were: (1) Transmit Data Filtering; (2) Transmit Clock Generation; (3) Carrier Synthesizer; (4) Receive AGC; (5) Receive Data Filtering; (6) RF Oscillator Phase Noise; (7) Receive Carrier Selectivity; (8) Carrier Recovery; and (9) Timing Recovery.

Core Community Specifications for Electron Microprobe Operating Systems: Software, Quality Control, and Data Management Issues

NASA Technical Reports Server (NTRS)

Fournelle, John; Carpenter, Paul

2006-01-01

Modem electron microprobe systems have become increasingly sophisticated. These systems utilize either UNIX or PC computer systems for measurement, automation, and data reduction. These systems have undergone major improvements in processing, storage, display, and communications, due to increased capabilities of hardware and software. Instrument specifications are typically utilized at the time of purchase and concentrate on hardware performance. The microanalysis community includes analysts, researchers, software developers, and manufacturers, who could benefit from exchange of ideas and the ultimate development of core community specifications (CCS) for hardware and software components of microprobe instrumentation and operating systems.

Customer Churn Prediction for Broadband Internet Services

NASA Astrophysics Data System (ADS)

Huang, B. Q.; Kechadi, M.-T.; Buckley, B.

Although churn prediction has been an area of research in the voice branch of telecommunications services, more focused studies on the huge growth area of Broadband Internet services are limited. Therefore, this paper presents a new set of features for broadband Internet customer churn prediction, based on Henley segments, the broadband usage, dial types, the spend of dial-up, line-information, bill and payment information, account information. Then the four prediction techniques (Logistic Regressions, Decision Trees, Multilayer Perceptron Neural Networks and Support Vector Machines) are applied in customer churn, based on the new features. Finally, the evaluation of new features and a comparative analysis of the predictors are made for broadband customer churn prediction. The experimental results show that the new features with these four modelling techniques are efficient for customer churn prediction in the broadband service field.

Ozone Measurements with the US EPA UV-DIAL: Preliminary Results

NASA Technical Reports Server (NTRS)

Moosmueller, H.; Diebel, D.; Bundy, D. H.; Bristow, M. P.; Alvarez, R. J., II; Kovalev, V. A.; Edmonds, C. M.; Turner, R. M.; Mcelroy, J. L.

1992-01-01

A compact airborne down-looking lidar system was developed at the Environmental Protection Agency in Las Vegas. This differential absorption lidar (DIAL) was designed to simultaneously measure range-resolved concentrations of ozone (O3) and sulfur dioxide (SO2) in the lower troposphere, together with an indication of the aerosol distribution. The five laser wavelengths (i.e., lambda(sub 1) = 277 nm, lambda(sub 2) = 292 nm, lambda(sub 3) = 313 nm, lambda(sub4) = 319 nm, lambda(sub 5) = 369 nm) were generated via Raman conversion of a focused KrF excimer laser. The system is currently installed in a truck-based mobile laboratory. For the ground testing, an opening in the truck floor together with a folding mirror under the truck makes a horizontal, or upwardly inclined direction of measurement possible. Initial ground testing has been performed in the vicinity of a Desert Research Institute (DRI) ambient air monitoring site, located at Cottonwood Cove approximately 85 km south east of Las Vegas, Nevada. At this site O3 and SO2 concentrations are continuously monitored with an average accuracy better than +/- 10 percent. A temporary ozone measurement station with identical accuracy was set up at a distance to get a second point of comparison for the range-resolved DIAL measurements.

Effects of electromagnetic waves emitted from 3G+wi-fi modems on human semen analysis.

PubMed

Kamali, Koosha; Atarod, Mohammadmehdi; Sarhadi, Saeedeh; Nikbakht, Javad; Emami, Maryam; Maghsoudi, Robab; Salimi, Hormoz; Fallahpour, Bita; Kamali, Negar; Momtazan, Abdolreza; Ameli, Mojtaba

2017-10-25

The purpose of this study was to evaluate the effects of 3G+wifi modems on human sperm quality.A total of 40 semen specimens were gathered between March and September 2015, from healthy adult men. The sperm samples were divided into two groups - 3G+wi-fi exposed and unexposed groups. In the unexposed group, the specimens were shielded by aluminum foil in three layers and put into an incubator at a temperature of 37°C for 50 minutes. The exposed group was positioned in another room in an incubator at a temperature of 37°C for 50 minutes. A 3G+wi-fi modem was put into the same incubator and a laptop computer was connected to the modem and was downloading for the entire 50 minutes.Semen analysis was done for each specimen and comparisons between parameters of the two groups were done by using Kolmogorov-Smirnov study and a paired t-test. Mean percentage of sperm with class A and B motility were not significantly different in two groups (p = 0.22 and 0.54, respectively). In class C, it was significantly lower in the exposed group (p = 0.046), while in class D it was significantly higher (p = 0.022).Velocity curvilinear, velocity straight line, velocity average path, mean angular displacement, lateral displacement and beat cross frequency were significantly higher in the unexposed group. The limitation was the in vitro design. Electromagnetic waves (EMWs) emitted from 3G+wi-fi modems cause a significant decrease in sperm motility and velocity, especially in non-progressive motile sperms. Other parameters of semen analysis did not change significantly.EMWs, which are used in communications worldwide, are a suspected cause of male infertility. Many studies evaluated the effects of cell phones and wi-fi on fertility. To our knowledge, no study has yet been done to show the effects of EMWs emitted from 3G+wi-fi modems on fertility.Our study revealed a significant decrease in the quality of human semen after exposure to EMWs emitted from 3G+wi-fi modems.

[Japanese who affected modern medicine in Taiwan: obstetrics and gynecology].

PubMed

Wang, Ming-Tung

2009-12-01

This text describes the leaders who established the modem obstetrics and gynecology for Taiwan. during the Japan-colonizing period (1895-1945). These leaders are Mr. Kawasoye, M., Mr. Mukae K., and Mr. Magara M. The lives of these leaders were different, but they all strongly contributed to the development of modem obstetrics and gynecology in Taiwan. With regard to the passage of time, Mr. Kawasoye contributed the initial efforts, Mr. Mukae worked during the flourishing period of the clinic; and Mr. Magara worked during the mature period, emphasizing research. These three periods are closely correlated with the course of the development of modem obstetrics and gynecology in Taiwan.

Response Rates in Random-Digit-Dialed Telephone Surveys: Estimation vs. Measurement.

ERIC Educational Resources Information Center

Franz, Jennifer D.

The efficacy of the random digit dialing method in telephone surveys was examined. Random digit dialing (RDD) generates a pure random sample and provides the advantage of including unlisted phone numbers, as well as numbers which are too new to be listed. Its disadvantage is that it generates a major proportion of nonworking and business…

The effect of three culture methods on intensive culture system of pacific white shrimp ( Litopenaeus vannamei)

NASA Astrophysics Data System (ADS)

Ma, Zhen; Wan, Rong; Song, Xiefa; Gao, Lei

2013-09-01

Different culture methods may affect the intensive culture system of Pacific white shrimp ( Litopenaeus vannamei) regarding water quality and growth and economic performance. This study evaluated the potential effects of three culture methods through cultivation of juvenile shrimps under consistent tank management conditions for 84 d. The three methods involved shrimp cultivation in different tanks, i.e., outdoor tanks with cement bottom (mode-C), greenhouse tanks with cement bottom (mode-G) and outdoor tanks with mud-substrate (mode-M). Results showed that water temperature was significantly higher in mode-G than that in mode-C ( P < 0.05). In contrast to the other two treatments, mode-M had stable pH after 50 d cultivation of shrimps. In the mid-late period, the average concentrations of TAN, NO2-N, DIP and COD were significantly lower in mode-M and mode-G compared with those in mode-C ( P < 0.05). Despite lack of differences in the final shrimp weight among different treatments ( P > 0.05), mode-M had significantly higher shrimp yield, survival rate and feed conversion rate ( P < 0.05) than other modes. There were significant differences in revenue and net return among different treatments ( P < 0.05). These demonstrated that the treatments of mode-G and mode-M were conductive to the intensive culture system of L. vannamei.

39. View of bridge operators controls in the control house ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

39. View of bridge operators controls in the control house facing south. Controls on the right are for the south span and on the left for the north span. The large dial indicator towards the top of the picture is a position indicator for the south span. Also present is a marine radio for talking to marine traffic and control ropes for the horn and siren. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

Remote Sensing of Turbine Engine Gases.

DTIC Science & Technology

1981-09-30

Institute by lasers operating in the infrared compared to the visible and of Technology. Lexington, M A 0217 3. UV region. 00l8.9197/81/0900-1917S00.75 0...mini-TEA lasers used in both single- and dual- laser consists of a UV -preionized discharge between Rogowski laser DIAL systems, and a study has been...described previously [10]. The discharge is thyratron system. This research has led to a better understanding of triggered and may operate at a pulse

Simple, affordable, and sustainable borehole observatories for complex monitoring objectives

NASA Astrophysics Data System (ADS)

Kopf, A.; Freudenthal, T.; Ratmeyer, V.; Bergenthal, M.; Lange, M.; Fleischmann, T.; Hammerschmidt, S.; Seiter, C.; Wefer, G.

2015-05-01

Seafloor drill rigs are remotely operated systems that provide a cost-effective means to recover sedimentary records of the upper sub-seafloor deposits. Recent increases in their payload included downhole logging tools or autoclave coring systems. Here we report on another milestone in using seafloor rigs: the development and installation of shallow borehole observatories. Three different systems have been developed for the MARUM-MeBo (Meeresboden-Bohrgerat) seafloor drill, which is operated by MARUM, University of Bremen, Germany. A simple design, the MeBoPLUG, separates the inner borehole from the overlying ocean by using o-ring seals at the conical threads of the drill pipe. The systems are self-contained and include data loggers, batteries, thermistors and a differential pressure sensor. A second design, the so-called MeBoCORK (Circulation Obviation Retrofit Kit), is more sophisticated and also hosts an acoustic modem for data transfer and, if desired, fluid sampling capability using osmotic pumps. In these MeBoCORKs, two systems have to be distinguished: the CORK-A (A stands for autonomous) can be installed by the MeBo alone and monitors pressure and temperature inside and above the borehole (the latter for reference); the CORK-B (B stands for bottom) has a higher payload and can additionally be equipped with geochemical, biological or other physical components. Owing to its larger size, it is installed by a remotely operated underwater vehicle (ROV) and utilises a hot-stab connection in the upper portion of the drill string. Either design relies on a hot-stab connection from beneath in which coiled tubing with a conical drop weight is lowered to couple to the formation. These tubes are fluid-saturated and either serve to transmit pore pressure signals or collect porewater in the osmo-sampler. The third design, the MeBoPUPPI (Pop-Up Pore Pressure Instrument), is similar to the MeBoCORK-A and monitors pore pressure and temperature in a self-contained manner. Instead of transferring data on command using an acoustic modem, the MeBoPUPPI contains a pop-up telemetry with iridium link. After a predefined period, the data unit with satellite link is released, ascends to the sea surface, and remains there for up to 2 weeks while sending the long-term data sets to shore. In summer 2012, two MeBoPLUGs, one MeBoCORK-A and one MeBoCORK-B were installed with MeBo on RV Sonne, Germany, in the Nankai Trough area, Japan. We have successfully downloaded data from the CORKs, attesting that coupling to the formation worked, and pressure records were elevated relative to the seafloor reference. In the near future, we will further deploy the first two MeBoPUPPIs. Recovery of all monitoring systems by a ROV is planned for 2016.

Development and application of a Controlled Release Facility (CRF) to validate flux quantifying methodologies.

NASA Astrophysics Data System (ADS)

Helmore, Jonathan

2017-04-01

The National Physical Laboratory, the UK's National Measurement Institute, has developed a novel facility capable of replicating the gaseous emission flux characteristics of a variety of real-word scenarios as may be found in small to medium scale industry and agriculture. The Controlled Release Facility (CRF) can be used to challenge conventional remote sensing techniques, as well as validate new Unmanned Aerial Vehicle (UAV) and distributed sensor network based methods, for source identification and flux calculation. The CRF method will be described and the results from three case studies will be discussed: The replication of an operational on-shore shale gas well using emissions of natural gas to atmosphere and measurements using Differential Absorption LIDAR (DIAL); the replication of fugitive volatile organic compounds emissions from a petrochemical unit and measurements using DIAL; and the replication of methane and carbon dioxide emissions from landfill and measurements using both fixed wing and multi-rotor UAVs.

Solid-State 2-Micron Laser Transmitter Advancement for Wind and Carbon Dioxide Measurements From Ground, Airborne, and Space-Based Lidar Systems

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Kavaya, Michael J.; Koch, Grady; Yu, Jirong; Ismail, Syed

2008-01-01

NASA Langley Research Center has been developing 2-micron lidar technologies over a decade for wind measurements, utilizing coherent Doppler wind lidar technique and carbon dioxide measurements, utilizing Differential Absorption Lidar (DIAL) technique. Significant advancements have been made towards developing state-of-the-art technologies towards laser transmitters, detectors, and receiver systems. These efforts have led to the development of solid-state lasers with high pulse energy, tunablility, wavelength-stability, and double-pulsed operation. This paper will present a review of these technological developments along with examples of high resolution wind and high precision CO2 DIAL measurements in the atmosphere. Plans for the development of compact high power lasers for applications in airborne and future space platforms for wind and regional to global scale measurement of atmospheric CO2 will also be discussed.

ILLUMA-T (Integrated LCRD LEO User Modem and Amplifier Terminal) Payload

NASA Technical Reports Server (NTRS)

Seas, Antonios; Gonnsen, Zachary; Yarnall, Timothy

2018-01-01

Presentation on ILLUMA-T (Integrated LCRD LEO User Modem and Amplifier Terminal) Payload at the Japanese Experiment Module (JEM) External Payload Interface Coordination Meeting on May 9, 2018 at the Japan Aerospace Exploration Agency (JAXA) in Tsukuba, Japan. Meeting to discuss details of installing payload on JEM.

A Study of Computer-Modem Students: A Call for Action.

ERIC Educational Resources Information Center

Richards, Irving; And Others

Offering participation in courses via modem can benefit both colleges, which are often coping with downsizing or insufficient classroom space, and students, who may face prohibitive work schedules, a need to remain at home, physical handicaps, or incarceration. This study assembles demographic information on higher education students who…

Office Automation and the Navy Finance Center.

DTIC Science & Technology

1984-09-01

inexpensive premise-distribution cable. - r wide range o protocols and transmission speeds. - Modem -pooling. Modems can be accessed on an as-needeo...the IBM System Nerworr Architecture (SNA and is composed of four 56K baud ii ne [Ref. IT]. 4. Protocop L ers NFC has Kodak and Royal copiers

Army Communicator. Volume 33, Number 3, Summer 2008. WIN-T: Increasing the Power of Battlefield Communications

DTIC Science & Technology

2008-01-01

Increment 2 will provide unprecedented network connectivity for Brigade Combat Teams while they quickly traverse the battlefield during fast moving... fast . As you know, just working with the Directorate of Information Management with your computer, you need constant patches, up- grades, updates...designed for fast acquisition and requisition. The modem will reacquire bursts within a second for short duration or intermittent blockages. Should the user

General Aviation Light Aircraft Propulsion: From the 1940's to the Next Century

NASA Technical Reports Server (NTRS)

Burkardt, Leo A.

1998-01-01

Current general aviation light aircraft are powered by engines that were originally designed in the 1940's. This paper gives a brief history of light aircraft engine development, explaining why the air-cooled, horizontally opposed piston engine became the dominant engine for this class of aircraft. Current engines are fairly efficient, and their designs have been updated through the years, but their basic design and operational characteristics are archaic in comparison to modem engine designs, such as those used in the automotive industry. There have been some innovative engine developments, but in general they have not been commercially successful. This paper gives some insight into the reasons for this lack of success. There is now renewed interest in developing modem propulsion systems for light aircraft, in the fore-front of which is NASA's General Aviation Propulsion (GAP) program. This paper gives an overview of the engines being developed in the GAP program, what they will mean to the general aviation community, and why NASA and its industry partners believe that these new engine developments will bring about a new era in general aviation light aircraft.

802.16e System Profile for NASA Extra-Vehicular Activities

NASA Technical Reports Server (NTRS)

Foore, Lawrence R.; Chelmins, David T.; Nguyen, Hung D.; Downey, Joseph A.; Finn, Gregory G.; Cagley, Richard E.; Bakula, Casey J.

2009-01-01

This report identifies an 802.16e system profile that is applicable to a lunar surface wireless network, and specifically for meeting extra-vehicular activity (EVA) data flow requirements. EVA suit communication needs are addressed. Design-driving operational scenarios are considered. These scenarios are then used to identify a configuration of the 802.16e system (system profile) that meets EVA requirements, but also aim to make the radio realizable within EVA constraints. Limitations of this system configuration are highlighted. An overview and development status is presented by Toyon Research Corporation concerning the development of an 802.16e compatible modem under NASA s Small Business Innovative Research (SBIR) Program. This modem is based on the recommended system profile developed as part of this report. Last, a path forward is outlined that presents an evolvable solution for the EVA radio system and lunar surface radio networks. This solution is based on a custom link layer, and 802.16e compliant physical layer compliant to the identified system profile, and a later progression to a fully interoperable 802.16e system.

A Model-based Framework for Risk Assessment in Human-Computer Controlled Systems

NASA Technical Reports Server (NTRS)

Hatanaka, Iwao

2000-01-01

The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems. This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions. Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

[The place and the role of topographic and clinical anatomy in the modern system of higher medical education].

PubMed

Bol'shakov, O P

2008-01-01

Modern data on studying and teaching topographic and clinical anatomy in Russia and in the foreign countries at the boundary between the XX and the XXI centuries are analyzed. Definitions of some concepts are given; methodological and organizational bases of studying topographic and clinical anatomy are examined in historical aspect. Various approaches to the teaching and studying of these disciplines in different countries, are demonstrated. Special attention is given to the use of new technologies in teaching; the experience of virtual mode of studying of applied anatomy and surgical techniques is critically evaluated. Article presents author's own opinion and analyzes the conceptions of the foreign authors on the necessity of rational combination of computer and other modem technologies with traditional methods of work using biological materials and experiments on laboratory animals. The longstanding experience of the departments of operative surgery and clinical anatomy is summarized and the benefits of the national system of teaching of applied (topographic and clinical) anatomy are shown. Modem tendencies and priorities in the development of topographic and clinical anatomy are demonstrated.

Safety Metrics for Human-Computer Controlled Systems

NASA Technical Reports Server (NTRS)

Leveson, Nancy G; Hatanaka, Iwao

2000-01-01

The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems.This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

Putting a Medical Library Online: Phase III--Remote Access to CD-ROMs.

ERIC Educational Resources Information Center

Kittle, Paul

1989-01-01

Describes the implementation of a project that provides dial-up access to MEDLINE on remote optical data disk (CD-ROM) using software that enables callers to use programs like Wordstar, Lotus, and dBase. Highlights include networking CD-ROM databases, hardware considerations, advantages and disadvantages of remote access, and future plans. A…

Homework or Not? That Is the Research Question

ERIC Educational Resources Information Center

DeNisco, Alison

2013-01-01

Woe unto the administrator who ventures forth into the homework wars. Scale it back, and parents will be at your door complaining about a lack of academic rigor. Dial it up, and you will get an earful from other parents about interference with after-school activities and family time. If you are looking to bolster your particular position with…

Dialing Up an Embryo: Are Olfactory Receptors Digits in a Developmental Code?

ERIC Educational Resources Information Center

Travis, John

1998-01-01

Scientist William J. Dreyer has hypothesized that the cell surface proteins in the nose that detect odors also help assemble embryos. These olfactory receptors and related proteins act as identifiers, much like the last few digits of a telephone number, that help cells to find their intended neighbors in a developing embryo. Discusses the research…

How cocrystals of weakly basic drugs and acidic coformers might modulate solubility and stability.

PubMed

Kuminek, G; Rodríguez-Hornedo, N; Siedler, S; Rocha, H V A; Cuffini, S L; Cardoso, S G

2016-04-30

Cocrystals of a weakly basic drug (nevirapine) with acidic coformers are shown to alter the solubility dependence on pH, and to exhibit a pHmax above which a less soluble cocrystal becomes more soluble than the drug. The cocrystal solubility advantage can be dialed up or down by solution pH.

Approaching the Affective Factors of Information Seeking: The Viewpoint of the Information Search Process Model

ERIC Educational Resources Information Center

Savolainen, Reijo

2015-01-01

Introduction: The article contributes to the conceptual studies of affective factors in information seeking by examining Kuhlthau's information search process model. Method: This random-digit dial telephone survey of 253 people (75% female) living in a rural, medically under-serviced area of Ontario, Canada, follows-up a previous interview study…

Microwave Tube Reliability

DTIC Science & Technology

1976-06-01

t’ibes discussed demonstrate a 2000-hour life in the laboratory but exhibit only a 200- hour i’fc in systems. The tubes reported on were broadband , helix ...control. Two such critical operations are helix winding and pyrolytic deposition. The ,slow-wave structureof .he modem TWT -is rarely a simple uniform...Il No customer complaint (2) 1I Open helix (1) 1 High harmonics, low power<l) The group A and B -symptoms indicated by the failure report data weL

Department of the Navy Justification of Estimates for Fiscal Year 1987 Submitted to Congress February 1986. Operation & Maintenance, Navy. Book 2. Budget Activity 7: Central Supply and Maintenance.

DTIC Science & Technology

1986-02-01

supported and trained. 242 294 250 .W - Telecommunications lines/ modems / multiplexes/controller 55 62 55 ,. .. CPU/time-sharing usage cycles (MIL) 132 160...46K BBLS 56K BBLS 56K B. Ship Energy 100 82 65 Conservation Savinqs 19K P.BLS 19 K BBLS 19K BBLS *BBLS = Barrels of oil saved n. SHIP SYSTEMS 1. Ship

Multi-channel Auto-dilution System for Remote Continuous Monitoring of High Soil-CO2 Fluxes

NASA Astrophysics Data System (ADS)

Barr, J. L.; Amonette, J. E.

2008-12-01

We describe a novel field instrument that takes input from up to 27 soil flux chambers and measures flux using the steady-state method. CO2 concentrations are determined with an infrared gas analyzer (IRGA, 0- 3000 ppmv range) with corrections for temperature, barometric pressure, and moisture content. The concentrations are monitored during data collection and, if they exceed the range of the IRGA, a stepped dilution program is automatically implemented that allows up to 50-fold dilution of the incoming gas stream with N2 supplied by boil-off from a large dewar. The upper concentration limit of the system with dilution is extended to at least 150,000 ppmv CO2. The data are stored on a datalogger having a cellular modem connection that allows remote control of the system as well as transmittal of data. The system is designed to operate for six weeks with no on-site maintenance required. Longer periods are possible with modifications to allow on-site generation of N2 from air. Example data from a recent CO2 test injection at the Zero- Emission Research and Technology (ZERT) field site in Bozeman, MT are presented.

Design and development aspects of flexure mechanism for high precision application

NASA Astrophysics Data System (ADS)

Sollapur, Shrishail B.; Patil, M. S.; Deshmukh, S. P.

2018-04-01

Planer XY Flexurel Mechanisms has various applications in precision motion mechanisms. A flexural mechanism generates relative motion between fixed support and motion stage using flexibility of material. This mechanism offers zero backlash, frictionless motion and high order repeatability. It is relatively compact in design as compared to rigid link mechanism. The merits of using flexure is complete mechanism can be from single monolith. Modelling of flexural mechanism to provide accurate scanning of comparatively larger range at a higher speed. Static Analysis of mechanism is carried out on FEA tool to determine static deflection of motion stage. Further Mechanism is actuated with the help of weight pan and weights. The resultant displacement is measured on Dial Gauge Indicator. Experimental set-up consists of Flexural mechanism, Dial Gauge, Weight Pan and Weights, Pulley, String, Small metal strip, Optical Bread Board etc. Further experimental Results and Analytical Results are compared and minimum deviation is found.

Setting up a mobile Lidar (DIAL) system for detecting chemical warfare agents

NASA Astrophysics Data System (ADS)

Kavosh Tehrani, M.; Mohammad, M. Malek; Jaafari, E.; Mobashery, A.

2015-03-01

The mobile light detection and ranging DIAL system of Malek Ashtar University of Technology has been developed for the detection of chemical warfare agents whose absorption wavelengths are in the range of 9.2-10.8 μm tunable CO2 lasers of the system. In this paper, this system is first described and then ammonia detection is analyzed experimentally. Also, experimental results of detecting a sarin agent simulant, dimethyl-methyl phosphonate (DMMP), are presented. The power levels received from different ranges to detect specific concentrations of NH3 and DMMP have been measured and debated. The primary test results with a 150 ns clipped pulse width by passive pinhole plasma shutter indicate that the system is capable of monitoring several species of pollutants in the range of about 1 km, with a 20 m spatial and 2 min temporal resolution.

A Compact Ti:Sapphire Laser With its Third Harmonic Generation (THG) for an Airborne Ozone Differential Absorption Lidar (DIAL) Transmitter

NASA Technical Reports Server (NTRS)

Chen, Songsheng; Storm, Mark E.; Marsh, Waverly D.; Petway, Larry B.; Edwards, William C.; Barnes, James C.

2000-01-01

A compact and high-pulse-energy Ti:Sapphire laser with its Third Harmonic Generation (THG) has been developed for an airborne ozone differential absorption lidar (DIAL) to study the distributions and concentrations of the ozone throughout the troposphere. The Ti:Sapphire laser, pumped by a frequency-doubled Nd:YAG laser and seeded by a single mode diode laser, is operated either at 867 nm or at 900 nm with a pulse repetition frequency of 20 Hz. High energy laser pulses (more than 110 mJ/pulse) at 867 nm or 900 nm with a desired beam quality have been achieved and utilized to generate its third harmonic at 289nm or 300nm, which are on-line and off-line wavelengths of an airborne ozone DIAL. After being experimentally compared with Beta-Barium Borate (beta - BaB2O4 or BBO) nonlinear crystals, two Lithium Triborate (LBO) crystals (5 x 5 x 20 cu mm) are selected for the Third Harmonic Generation (THG). In this paper, we report the Ti:Sapphire laser at 900 nm and its third harmonic at 300 nm. The desired high ultraviolet (UV) output pulse energy is more than 30 mJ at 300 nm and the energy conversion efficiency from 900 nm to 300 nm is 30%.

The Iowa Flood Center's River Stage Sensors—Technical Details

NASA Astrophysics Data System (ADS)

Niemeier, J. J.; Kruger, A.; Ceynar, D.; Fahim Rezaei, H.

2012-12-01

The Iowa Flood Center (IFC), along with support from the Iowa Department of Transportation (DOT) and the Iowa Department of Natural Resources (DNR) have developed a bridge-mounted river stage sensor. Each sensor consists of an ultrasonic distance measuring module, cellular modem, a GPS unit that provides accurate time and an embedded controller that orchestrates the sensors' operation. A sensor is powered by a battery and solar panel along with a solar charge controller. All the components are housed in/on a sturdy metal box that is then mounted on the side of a bridge. Additionally, each sensor incorporates a water-intrusion sensor and an internal temperature sensor. In operation, the microcontroller wakes, and turns on the electronics every 15 minutes and then measures the distance between the ultrasonic sensor and the water surface. Several measurements are averaged and transmitted along with system health information (battery voltage, state of water intrusion sensor, and internal temperature) via cellular modem to remote servers on the internet. The microcontroller then powers the electronics down and enters a sleep/power savings mode. The sensor's firmware allows the remote server to adjust the measurement rate to 5, 15, and 60 minutes. Further, sensors maintain a 24-day buffer of previous measurements. If a sensor could not successfully transmit its data because of cellular network connection problems, it will transmit the backlog on subsequent transmissions. We paid meticulous attention to all engineering aspects and sensors are very robust and have operated essentially continuously through two Iowa winters and summers, including the 2012 record-breaking warm summer.

Simple, affordable and sustainable borehole observatories for complex monitoring objectives

NASA Astrophysics Data System (ADS)

Kopf, A.; Freudenthal, T.; Ratmeyer, V.; Bergenthal, M.; Lange, M.; Fleischmann, T.; Hammerschmidt, S.; Seiter, C.; Wefer, G.

2014-12-01

Seafloor drill rigs are remotely operated systems that provide a cost effective means to recover sedimentary records of the upper sub-seafloor deposits. Recent increases in their payload included downhole logging tools or autoclave coring systems. We here report on another milestone in using seafloor rigs: the development and installation of shallow borehole observatories. Three different systems have been developed for the MARUM-MeBo seafloor drill, which is operated by MARUM, University of Bremen, Germany. A simple design, the MeBoPLUG, separates the inner borehole from the overlying ocean by using o-ring seals at the conical threads of the drill pipe. The systems are self-contained and include data loggers, batteries, thermistors and a differential pressure sensor. A second design, the so-called MeBoCORK, is more sophisticated and also hosts an acoustic modem for data transfer and, if desired, fluid sampling capability using osmotic pumps. Of these MeBoCORKs, two systems have to be distinguished: the CORK-A (A = autonomous) can be installed by the MeBo alone and monitors pressure and temperature inside and above the borehole (the latter for reference). The CORK-B (B = bottom) has a higher payload and can additionally be equipped with geochemical, biological or other physical components. Owing to its larger size, it is installed by ROV and utilises a hotstab connection in the upper portion of the drill string. Either design relies on a hotstab connection from beneath which coiled tubing with a conical drop weight is lowered to couple to the formation. These tubes are fluid-saturated and either serve to transmit pore pressure signals or collect pore water in the osmo-sampler. The third design, the MeBoPUPPI (Pop-Up Pore Pressure Instrument), is similar to the MeBoCORK-A and monitors pore pressure and temperature in a self-contained manner. Instead of transferring data upon command using an acoustic modem, the MeBoPUPPI contains a pop-up telemetry with Iridium link. After a predefined period, the data unit with satellite link is released, ascends to the sea surface, and remains there for up to two weeks while sending the long-term data sets to shore. In summer 2012, two MeBoPLUGs, one MeBoCORK-A and one MeBoCORK-B were installed with MeBo on German RV Sonne in the Nankai Trough area, Japan. We have successfully downloaded data from the CORKs, attesting that coupling to the formation worked and pressure records were elevated relative to the seafloor reference. In the near future, we will further deploy the first two MeBoPUPPIs. Recovery of all monitoring systems by ROV is planned for 2016.

Reconnecting with urban youth enrolled in a randomized controlled trial and overdue for a 12-month follow-up survey

PubMed Central

Ezell, Jerel M.; Saltzgaber, Jacquelyn; Peterson, Edward; Joseph, Christine LM

2013-01-01

Background Retention of study participants in randomized controlled trials (RCTs) is crucial to study validity. Purpose We analyzed the result of four retention strategies used to reconnect with urban teens enrolled in a school-based randomized controlled trial (RCT) and overdue for a 12-month follow-up survey. Methods Traditional retention strategies used to reconnect with teens categorized as “unable to contact” were weekly re-dials of non-working telephone numbers and mailings to the student’s home. Non-traditional retention strategies were obtaining assistance from school administration and communication through Facebook. Results Of the 422 students enrolled, 125 (29.5%) were overdue for a 12-month follow-up survey, but had no working telephone number (unable to contact). We made 196 attempts to contact these 125 students, of which 82 attempts (41.8%) were successful in “reconnecting,” defined as (1) a student contacting research staff as a result of a mailed notice; (2) a research staff member leaving a voicemail at a previously disconnected telephone number; (3) a student responding to Facebook outreach; or (4) research staff obtaining a new telephone number and talking to a person at the new telephone number. We used “ mailed reminder letters” as the referent category, in our analysis. Odds ratios (95% confidence intervals) for the association between the strategy used and success (“reconnecting”) for telephone number re-dials, Facebook, and school administration assistance were 4.60 (1.8–11.8), 1.94 (1.01–3.73), and 2.91 (0.58–14.50), respectively. Limitations Retention strategies were not applied hierarchically or systematically across students, and we were unable to ascertain student preference for a particular strategy. In addition, our findings may be applicable only to study populations with characteristics similar to those of students included in this study. Conclusion Overall, of the 422 students who enrolled in the study, 380 (90%), ultimately completed the 12-month follow-up survey. A mix of traditional retention strategies, such as telephone number re-dials, and more contemporary methods, such as use of Facebook, were effective in reconnecting with urban teenagers enrolled in a school-based RCT, and controlling attrition during the 12-month follow-up survey period. PMID:23983157

A Water Vapor Differential Absorption LIDAR Design for Unpiloted Aerial Vehicles

NASA Technical Reports Server (NTRS)

DeYoung, Russell J.; Mead, Patricia F.

2004-01-01

This system study proposes the deployment of a water vapor Differential Absorption LIDAR (DIAL) system on an Altair unmanned aerial vehicle (UAV) platform. The Altair offers improved payload weight and volume performance, and longer total flight time as compared to other commercial UAV's. This study has generated a preliminary design for an Altair based water vapor DIAL system. The design includes a proposed DIAL schematic, a review of mechanical challenges such as temperature and humidity stresses on UAV deployed DIAL systems, an assessment of the available capacity for additional instrumentation (based on the proposed design), and an overview of possible weight and volume improvements associated with the use of customized electronic and computer hardware, and through the integration of advanced fiber-optic and laser products. The results of the study show that less than 17% of the available weight, less than 19% of the volume capacity, and approximately 11% of the electrical capacity is utilized by the proposed water vapor DIAL system on the Altair UAV.

I 5683 you: dialing phone numbers on cell phones activates key-concordant concepts.

PubMed

Topolinski, Sascha

2011-03-01

When people perform actions, effects associated with the actions are activated mentally, even if those effects are not apparent. This study tested whether sequences of simulations of virtual action effects can be integrated into a meaning of their own. Cell phones were used to test this hypothesis because pressing a key on a phone is habitually associated with both digits (dialing numbers) and letters (typing text messages). In Experiment 1, dialing digit sequences induced the meaning of words that share the same key sequence (e.g., 5683, LOVE). This occurred even though the letters were not labeled on the keypad, and participants were not aware of the digit-letter correspondences. In Experiment 2, subjects preferred dialing numbers implying positive words (e.g., 37326, DREAM) over dialing numbers implying negative words (e.g., 75463, SLIME). In Experiment 3, subjects preferred companies with phone numbers implying a company-related word (e.g., LOVE for a dating agency, CORPSE for a mortician) compared with companies with phone numbers implying a company-unrelated word.

Inexpensive E-mail Systems for LANs and Dial-up.

ERIC Educational Resources Information Center

Pfaffman, Jay

Internet e-mail is becoming more accessible to K-12 teachers. Many colleges and universities will give accounts to teachers for the price of asking. Unfortunately, many of these university systems are hard to use and are usually not offered to K-12 students. Also, most schools do not have phone lines in classrooms. This paper discusses two systems…

How cocrystals of weakly basic drugs and acidic coformers might modulate solubility and stability

PubMed Central

Kuminek, G.; Rodríguez-Hornedo, N.; Siedler, S.; Rocha, H. V. A.; Cuffini, S. L.; Cardoso, S. G.

2016-01-01

Cocrystals of a weakly basic drug (nevirapine) with acidic coformers are shown to alter the solubility dependence on pH, and to exhibit a pHmax above which a less soluble cocrystal becomes more soluble than the drug. The cocrystal solubility advantage can be dialed up or down by solution pH. PMID:27042997

University Student's Perspectives on Using Cell Phones in Classrooms--Are They Dialing up Disaster?

ERIC Educational Resources Information Center

Fernandez, Simon

2018-01-01

Mobile phones are one of the fastest growing technologies in this century all over the world and these devices are extremely influencing the adolescents. The present study was sought to establish students' views on cell phones usage in university classrooms in an educational district in the Eastern Cape Province of South Africa. The study employed…

Cell Phones in the Classroom: Are We Dialing up Disaster?

ERIC Educational Resources Information Center

Engel, George; Green, Tim

2011-01-01

Over the last decade there has been a rapid diffusion of cellular technology. Though cell phone use began as a business tool, it has now become part of popular culture. Because of the near ubiquitous presence of cell phone technology among teens in the United States, schools are beginning to explore the use of cell phones as a learning tool. This…

E-Rate Program Seen as Too Lean for a Digital Era

ERIC Educational Resources Information Center

Klein, Alyson

2013-01-01

As school districts strive to put more technology into schools to support 1-to-1 computing initiatives and prepare for the common-core online assessments, the federal E-rate program is in danger of becoming as outdated and insufficient as a sputtering dial-up connection in a Wi-Fi world. While the program can boast great success since its…

Practical performance evaluation of the Wave Glider in geophysical observations

NASA Astrophysics Data System (ADS)

Sugioka, Hiroko; Hamano, Yozo

2016-04-01

The Wave Glider (WG), manufactured by Liquid Robotics Inc. of California, USA, is the first wave and solar powered autonomous sea surface vehicle. It has led the way to make ocean data collection and communications easier and safer, lower risk and cost, and real-time. By analyzing data from a long-term deployment of the WG in the sea to investigate the feasibility, an assessment of operating characteristics informs the potential utility of the WG to identify the parameters for a seafloor experiment designed the WG as a station-keeping gateway. We apply the WG in the following two observation systems that we have been developing. First, after the 2011 Tohoku earthquake tsunami, we have developed a real-time offshore tsunami monitoring system using a new type of seafloor tsunami sensor called Vector TsunaMeter (VTM) able to directly estimate the tsunami propagation vector based on the electromagnetic induction theory to provide early and reliable information at the coastal area. The WG equipped with both an acoustic modem and a satellite communication modem is used in the system as a relay platform for data transfer and communications between the sea bottom observatory and the land station. We had some experiments beginning with newly developing of the VTM in November 2012 to complete as a real-time monitoring system using the WG in March 2014. During the last experiment, we succeeded in detecting the micro-tsunami associated with the 2014 Iquique, Chile earthquake with Mw 8.2 on April 1 to confirm the practical utility of the WG. Second, since the Nishinoshima volcano of the Bonin Islands erupted in November 2013, we have been developing an isolated volcanic activity monitoring system using the unmanned WG vehicle. In this system the WG plays roles not only in a relay station with a satellite communication modem but also in a multi-purpose observatory platform with microphone for detecting acoustic waves in the air due to eruptions, with hydrophones for detecting acoustic and seismic waves in the ocean, and with wave gauges for detecting heave displacements due to volcano collapse tsunami. A brand new island was born by the first eruption on November 20, 2013. Over the past two years with continued volcanic activity, it has grown up to 12 times the size of the original, which is offering us a rare opportunity to study how volcanic island forms and grows. We will install the monitoring system as soon as possible.

Walk Softly and Carry a Big Stick: An Analysis of the Impact of Colonialism/Imperialism on the Operational Art for Campaign Planners Assigned to AFRICOM Using the Darfur Crisis as a Case Study

DTIC Science & Technology

2009-04-01

ineffectual, and irresponsive to their nation’s demands. Even today, free of colonial rule, the modem African nation state remains disadvantaged from...and Africa Security: The Globalisation of Security or the Militarisation of Globalisation ?," The Brenthurst Foundation. April 2007...Lorenzo and Matthew Utley. "AFRICOM and Africa Security: The Globalisation of Security or the Militarisation of Globalisation ?," The Brenthurst

Evaluation and Selection of a Telecommunication System at the Naval Postgraduate School BOQ

DTIC Science & Technology

1991-03-01

software, and operating system software as a part of a complete package. An internal modem must be included for remote diagnostic and programming...2 service delivery will follow the CCITT V.35 recommendation for physical, functional and electrical interfaces. Type 1 & 2 will transfer data at 56K ...by a dedicated access line at 4.8 kbs and 9.6 Kbps and 56k /64Kbps. PSS will follow the CCITT X.25 recommendations. E-mail service may be provided on

The Costs and Benefits of Pre-Planned Product Improvements for the Consolidated Automated Support System (CASS)

DTIC Science & Technology

1993-11-01

ground missions and must operate effectively in both domains . Figure A-3 shows a block diagram of a modem fighter radar3 system . Technologies that are...I AUTOMATED SUPPORT SYSTEM (CASS) I i Daniel B. Levine Waynard C. Devers, Project Leader Bernard L. Retterer Howard S. Savage Clayton V. Stewart...Improvements for theI Consolidated Automated Support System (CASS) MDA 903 89C 0003 6. AUThiOR( T-B7-1095 Daniel B. Levine, Waynard C. Devers

Refining, revising, augmenting, compiling and developing computer assisted instruction K-12 aerospace materials for implementation in NASA spacelink electronic information system

NASA Technical Reports Server (NTRS)

Blake, Jean A.

1988-01-01

The NASA Spacelink is an electronic information service operated by the Marshall Space Flight Center. The Spacelink contains extensive NASA news and educational resources that can be accessed by a computer and modem. Updates and information are provided on: current NASA news; aeronautics; space exploration: before the Shuttle; space exploration: the Shuttle and beyond; NASA installations; NASA educational services; materials for classroom use; and space program spinoffs.

A Direct Detection 1.6μm DIAL with Three Wavelengths for Measurements of Vertical CO2 Concentration and Temperature Profiles in the Atmosphere

NASA Astrophysics Data System (ADS)

Nagasawa, C.; Abo, M.; Shibata, Y.; Nagai, T.; Tsukamoto, M.

2012-12-01

We report the new 1.6 μm DIAL system that can measure the temperature profiles with the CO2 concentration profiles in the atmosphere because of improvement of measurement accuracy of the CO2 density and mixing ratio (ppm). We have developed a direct detection 1.6 μm differential absorption lidar (DIAL) technique to perform range-resolved measurements of vertical CO2 concentration profiles in the atmosphere [Sakaizawa et al. 2009]. Our 1.6 μm DIAL system consists of the Optical Parametric Generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz) and the receiving optics that included the near-infrared photomultiplier tube with high quantum efficiency operating at the photon counting mode and the telescope with larger aperture than that of the coherent detection method. Laser beams of three wavelengths around a CO2 absorption line is transmitted alternately to the atmosphere for measurements of CO2 concentration and temperature profiles. Moreover, a few retrieval algorithms of CO2-DIAL are also performed for improvement of measurement accuracy. The accurate vertical CO2 profiles in the troposphere are highly desirable in the inverse techniques to improve quantification and understanding of the global budget of CO2 and also global climate changes [Stephens et al. 2007]. In comparison with the ground-based monitoring network, CO2 measurements for vertical profiles in the troposphere have been limited to campaign-style aircraft and commercial airline observations with the limited spatial and temporal coverage. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References Sakaizawa, D., C. Nagasawa, T. Nagai, M. Abo, Y. Shibata, H. Nagai, M. Nakazato, and T. Sakai, Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric oscillator and photon-counting detector for the vertical CO2 profile, Applied Optics, Vol.48, No.4, pp.748-757, 2009. Stephens, B. B. et al., Weak Northern and Strong Tropical Land Carbon Uptake from Vertical Profiles of Atmospheric CO2, Science 316, pp.1732-1735, 2007.

Everything You Need To Know about American History Homework. A Desk Reference for Students and Parents. Scholastic Homework Reference Series.

ERIC Educational Resources Information Center

Zeman, Anne; Kelly, Kate

A volume in the Scholastic Homework Reference Series, this document provides fourth to sixth grade students and their parents with the information they need to complete U.S. history assignments. With the help of Dial-A-Teacher, which has operated a telephone helpline since 1979, this American history reference guide presents easy-to-understand…

A Heuristic Approach to the Theater Distribution Problem

DTIC Science & Technology

2014-03-27

outstanding guidance on this thesis research as well as the introduction to joint mobility modeling in OPER 674 which sparked my interest in this area of...32 xi List of Acronyms Acronym Definition AMP Analysis of Mobility Platform DARP Dial-A-Ride problem...tabu SMM Strategic Mobility Modeling TDD time definite delivery TDM Theater Distribution Model TDP Theater Distribution Problem TPFDD Time Phased Force

Digital Troposcatter Performance Model. Users Manual.

DTIC Science & Technology

1983-11-01

and Information Systems - .,- - - UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) S REPORT DOCUIAENTATION PAGE READ...Diffraction Multipath Prediction MD-918 Modem Error Rate Prediction AN/TRC-170 Link Analysis 20. ABSTRACT (Continue en reverse esie If neceseay end...configurations used in the Defense Communications System (DCS), and prediction of the performance of both the MD-918 and AN/TRC-170 digital troposcatter modems

DialBetics With a Multimedia Food Recording Tool, FoodLog: Smartphone-Based Self-Management for Type 2 Diabetes.

PubMed

Waki, Kayo; Aizawa, Kiyoharu; Kato, Shigeko; Fujita, Hideo; Lee, Hanae; Kobayashi, Haruka; Ogawa, Makoto; Mouri, Keisuke; Kadowaki, Takashi; Ohe, Kazuhiko

2015-05-01

Diabetes self-management education is an essential element of diabetes care. Systems based on information and communication technology (ICT) for supporting lifestyle modification and self-management of diabetes are promising tools for helping patients better cope with diabetes. An earlier study had determined that diet improved and HbA1c declined for the patients who had used DialBetics during a 3-month randomized clinical trial. The objective of the current study was to test a more patient-friendly version of DialBetics, whose development was based on the original participants' feedback about the previous version of DialBetics. DialBetics comprises 4 modules: data transmission, evaluation, exercise input, and food recording and dietary evaluation. Food recording uses a multimedia food record, FoodLog. A 1-week pilot study was designed to determine if usability and compliance improved over the previous version, especially with the new meal-input function. In the earlier 3-month, diet-evaluation study, HbA1c had declined a significant 0.4% among those who used DialBetics compared with the control group. In the current 1-week study, input of meal photos was higher than with the previous version (84.8 ± 13.2% vs 77.1% ± 35.1% in the first 2 weeks of the 3-month trial). Interviews after the 1-week study showed that 4 of the 5 participants thought the meal-input function improved; the fifth found input easier, but did not consider the result an improvement. DialBetics with FoodLog was shown to be an effective and convenient tool, its new meal-photo input function helping provide patients with real-time support for diet modification. © 2015 Diabetes Technology Society.

DialBetics With a Multimedia Food Recording Tool, FoodLog

PubMed Central

Waki, Kayo; Aizawa, Kiyoharu; Kato, Shigeko; Fujita, Hideo; Lee, Hanae; Kobayashi, Haruka; Ogawa, Makoto; Mouri, Keisuke; Kadowaki, Takashi; Ohe, Kazuhiko

2015-01-01

Background: Diabetes self-management education is an essential element of diabetes care. Systems based on information and communication technology (ICT) for supporting lifestyle modification and self-management of diabetes are promising tools for helping patients better cope with diabetes. An earlier study had determined that diet improved and HbA1c declined for the patients who had used DialBetics during a 3-month randomized clinical trial. The objective of the current study was to test a more patient-friendly version of DialBetics, whose development was based on the original participants’ feedback about the previous version of DialBetics. Method: DialBetics comprises 4 modules: data transmission, evaluation, exercise input, and food recording and dietary evaluation. Food recording uses a multimedia food record, FoodLog. A 1-week pilot study was designed to determine if usability and compliance improved over the previous version, especially with the new meal-input function. Results: In the earlier 3-month, diet-evaluation study, HbA1c had declined a significant 0.4% among those who used DialBetics compared with the control group. In the current 1-week study, input of meal photos was higher than with the previous version (84.8 ± 13.2% vs 77.1% ± 35.1% in the first 2 weeks of the 3-month trial). Interviews after the 1-week study showed that 4 of the 5 participants thought the meal-input function improved; the fifth found input easier, but did not consider the result an improvement. Conclusions: DialBetics with FoodLog was shown to be an effective and convenient tool, its new meal-photo input function helping provide patients with real-time support for diet modification. PMID:25883164

Mechanisms of breathing instability in patients with obstructive sleep apnea.

PubMed

Younes, Magdy; Ostrowski, Michele; Atkar, Raj; Laprairie, John; Siemens, Andrea; Hanly, Patrick

2007-12-01

The response to chemical stimuli (chemical responsiveness) and the increases in respiratory drive required for arousal (arousal threshold) and for opening the airway without arousal (effective recruitment threshold) are important determinants of ventilatory instability and, hence, severity of obstructive apnea. We measured these variables in 21 obstructive apnea patients (apnea-hypopnea index 91 +/- 24 h(-1)) while on continuous-positive-airway pressure. During sleep, pressure was intermittently reduced (dial down) to induce severe hypopneas. Dial downs were done on room air and following approximately 30 s of breathing hypercapneic and/or hypoxic mixtures, which induced a range of ventilatory stimulation before dial down. Ventilation just before dial down and flow during dial down were measured. Chemical responsiveness, estimated as the percent increase in ventilation during the 5(th) breath following administration of 6% CO(2) combined with approximately 4% desaturation, was large (187 +/- 117%). Arousal threshold, estimated as the percent increase in ventilation associated with a 50% probability of arousal, ranged from 40% to >268% and was <120% in 12/21 patients, indicating that in many patients arousal occurs with modest changes in chemical drive. Effective recruitment threshold, estimated as percent increase in pre-dial-down ventilation associated with a significant increase in dial-down flow, ranged from zero to >174% and was <110% in 12/21 patients, indicating that in many patients reflex dilatation occurs with modest increases in drive. The two thresholds were not correlated. In most OSA patients, airway patency may be maintained with only modest increases in chemical drive, but instability results because of a low arousal threshold and a brisk increase in drive following brief reduction in alveolar ventilation.

Measuring the Effectiveness of the Apparel Advanced Manufacturing Demonstration Program. Appendices B-E

DTIC Science & Technology

1990-12-30

DAVID were around cleaning up or counting A inventory. One whole floor of CHATHAM modem, automated equipment was __ draped with protective coverings...58 5060 N. Pire Street 11201 Armour Drive hazietor DA i8201 - ;Z Paso 7X 799:5 Mr. Sylvano aonarli Mr. Larry Price -resident Executive Vice...GA880493 Ncrti Ina.ustrl.a ark 440 Armour -:ace. . Rioley TN 38063 - Atlanta GA 30324 r. Riclarc Rin. Mr. Samuel S. Scnowls (y Er, ineerno ana.er

The Social and Behavioral Impacts of Information Systems in the Automated Office: A Literature Review

DTIC Science & Technology

1991-12-01

as in the home, in satellite offices, or any place where a portable computer can be hooked up to a modem. Concepts such as telecommuting and...and not being able to separate the work environment from the home environment. Kroll (1984) discusses the advantages of telecommuting as well as...management considerations in implementing a telecommuting program. She states that in 1984 less than one percent of the labor force was telecommuting but it

Design of an anti-Rician-fading modem for mobile satellite communication systems

NASA Technical Reports Server (NTRS)

Kojima, Toshiharu; Ishizu, Fumio; Miyake, Makoto; Murakami, Keishi; Fujino, Tadashi

1995-01-01

To design a demodulator applicable to mobile satellite communication systems using differential phase shift keying modulation, we have developed key technologies including an anti-Rician-fading demodulation scheme, an initial acquisition scheme, automatic gain control (AGC), automatic frequency control (AFC), and bit timing recovery (BTR). Using these technologies, we have developed one-chip digital signal processor (DSP) modem for mobile terminal, which is compact, of light weight, and of low power consumption. Results of performance test show that the developed DSP modem achieves good performance in terms of bit error ratio in mobile satellite communication environment, i.e., Rician fading channel. It is also shown that the initial acquisition scheme acquires received signal rapidly even if the carrier-to-noise power ratio (CNR) of the received signal is considerably low.

High data rate modem simulation for the space station multiple-access communications system

NASA Technical Reports Server (NTRS)

Horan, Stephen

1987-01-01

The communications system for the space station will require a space based multiple access component to provide communications between the space based program elements and the station. A study was undertaken to investigate two of the concerns of this multiple access system, namely, the issues related to the frequency spectrum utilization and the possibilities for higher order (than QPSK) modulation schemes for use in possible modulators and demodulators (modems). As a result of the investigation, many key questions about the frequency spectrum utilization were raised. At this point, frequency spectrum utilization is seen as an area requiring further work. Simulations were conducted using a computer aided communications system design package to provide a straw man modem structure to be used for both QPSK and 8-PSK channels.

Advanced Atmospheric Water Vapor DIAL Detection System

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

2000-01-01

Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

Calling for Help? Considering Function and Meaning when Patients Drunk-Dial Psychotherapists

PubMed Central

Serafini, Kelly; LaPaglia, Donna; Steinfeld, Matthew

2013-01-01

Drunk-dialing is a term documented in both popular culture and academic literatures to describe a behavior in which a person contacts another individual by phone while intoxicated. In our collective clinical experience we have found that clients drunk-dial their clinicians too, particularly while in substance use treatment, and yet there is a noticeable absence of research on the topic to guide clinical decision-making within a process-based understanding of these events. As the parameters within which psychotherapy takes place become increasingly technologized, a literature base to document clients’ idiosyncratic use of technology will become increasingly necessary and useful. We provide a brief review of the existing research on drunk-dialing and conclude with specific questions to guide future research and practice. PMID:24023519

Opo lidar sounding of trace atmospheric gases in the 3 - 4 μm spectral range

NASA Astrophysics Data System (ADS)

Romanovskii, Oleg A.; Sadovnikov, Sergey A.; Kharchenko, Olga V.; Yakovlev, Semen V.

2018-04-01

The applicability of a KTA crystal-based laser system with optical parametric oscillators (OPO) generation to lidar sounding of the atmosphere in the spectral range 3-4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases (TAG) is based on differential absorption lidar (DIAL) method and differential optical absorption spectroscopy (DOAS). The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases. The numerical simulation performed shows that a KTA-based OPO laser is a promising source of radiation for remote DIAL-DOAS sounding of the TAGs under study along surface tropospheric paths. A possibility of using a PD38-03-PR photodiode for the DIAL gas analysis of the atmosphere is shown.

Airborne lidar mapping of vertical ozone distributions in support of the 1990 Clean Air Act Amendments

NASA Technical Reports Server (NTRS)

Uthe, Edward E.; Nielsen, Norman B.; Livingston, John M.

1992-01-01

The 1990 Clean Air Act Amendments mandated attainment of the ozone standard established by the U.S. Environmental Protection Agency. Improved photochemical models validated by experimental data are needed to develop strategies for reducing near surface ozone concentrations downwind of urban and industrial centers. For more than 10 years, lidar has been used on large aircraft to provide unique information on ozone distributions in the atmosphere. However, compact airborne lidar systems are needed for operation on small aircraft of the type typically used on regional air quality investigations to collect data with which to develop and validate air quality models. Data presented in this paper will consist of a comparison between airborne differential absorption lidar (DIAL) and airborne in-situ ozone measurements. Also discussed are future plans to improve the airborne ultraviolet-DIAL for ozone and other gas observations and addition of a Fourier Transform Infrared (FTIR) emission spectrometer to investigate the effects of other gas species on vertical ozone distribution.

Development of Laser, Detector, and Receiver Systems for an Atmospheric CO2 Lidar Profiling System

NASA Technical Reports Server (NTRS)

Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Singh, Upendra

2008-01-01

A ground-based Differential Absorption Lidar (DIAL) is being developed with the capability to measure range-resolved and column amounts of atmospheric CO2. This system is also capable of providing high-resolution aerosol profiles and cloud distributions. It is being developed as part of the NASA Earth Science Technology Office s Instrument Incubator Program. This three year program involves the design, development, evaluation, and fielding of a ground-based CO2 profiling system. At the end of a three-year development this instrument is expected to be capable of making measurements in the lower troposphere and boundary layer where the sources and sinks of CO2 are located. It will be a valuable tool in the validation of NASA Orbiting Carbon Observatory (OCO) measurements of column CO2 and suitable for deployment in the North American Carbon Program (NACP) regional intensive field campaigns. The system can also be used as a test-bed for the evaluation of lidar technologies for space-application. This DIAL system leverages 2-micron laser technology developed under a number of NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements.

Implementation and flight tests for the Digital Integrated Automatic Landing System (DIALS). Part 1: Flight software equations, flight test description and selected flight test data

NASA Technical Reports Server (NTRS)

Hueschen, R. M.

1986-01-01

Five flight tests of the Digital Automated Landing System (DIALS) were conducted on the Advanced Transport Operating Systems (ATOPS) Transportation Research Vehicle (TSRV) -- a modified Boeing 737 aircraft for advanced controls and displays research. These flight tests were conducted at NASA's Wallops Flight Center using the microwave landing system (MLS) installation on runway 22. This report describes the flight software equations of the DIALS which was designed using modern control theory direct-digital design methods and employed a constant gain Kalman filter. Selected flight test performance data is presented for localizer (runway centerline) capture and track at various intercept angles, for glideslope capture and track of 3, 4.5, and 5 degree glideslopes, for the decrab maneuver, and for the flare maneuver. Data is also presented to illustrate the system performance in the presence of cross, gust, and shear winds. The mean and standard deviation of the peak position errors for localizer capture were, respectively, 24 feet and 26 feet. For mild wind conditions, glideslope and localizer tracking position errors did not exceed, respectively, 5 and 20 feet. For gusty wind conditions (8 to 10 knots), these errors were, respectively, 10 and 30 feet. Ten hands off automatic lands were performed. The standard deviation of the touchdown position and velocity errors from the mean values were, respectively, 244 feet and 0.7 feet/sec.

Mobile SO2 and NO2 DIAL Lidar system for enforcement use

NASA Astrophysics Data System (ADS)

Cunningham, David L.; Pence, William H.; Moody, Stephen E.

1994-06-01

A self-contained mobile differential absorption lidar (DIAL) system intended for measuring SO2 and NO2 concentrations from stationary combustion sources has been completed for enforcement use. The system uses tunable Ti:sapphire laser technology, with nonlinear conversion to the blue and UV absorption wavelengths. Separate tunable laser oscillators at slightly offset wavelengths are pumped on alternate pulses of a 20 Hz doubled Nd:YAG pump laser; the outputs are amplified in a common amplifier, doubled or tripled, and transmitted toward a target region via a two-mirror beam director. Scattered atmospheric returns are collected in a 0.27-m-diameter telescope, detected with a filtered photomultiplier, and digitized and stored for analysis. Extensive software-based control and display windows are provided for operator interaction with the system. The DIAL system is built into a small motor coach. Gasoline- powered electrical generation, laser cooling, and air conditioning services are present. Separate computers are provided for simultaneous data collection and data analysis activities, with shared data base access. A laser printer supplies hardcopy output. The system includes the capability for automatic data collection at a series of scanner angles, and computer processing to present results in a variety of formats. Plumes from coal-fired and mixed-fuel-fired combusters have been examined for NO2 and SO2 content. Noise levels of a few parts per million are reached with averaging times of less than one minute.

An introduction to testing techniques in the Intelsat TDMA/DSI system. II - Satellite system operations guide (SSOG) tests

NASA Astrophysics Data System (ADS)

Colby, R. J.; Parthasarathy, R.; Stimson, A. L.

1983-12-01

The test methods and procedures of the Intelsat TDMA/DSI SSOG are summarized. The overall structure of the SSOG is outlined, and the operational procedures to be followed for joining a new terminal to the system and for normal operations are reviewed, with an emphasis on the roles of the IOC and the TDMA reference and monitoring stations. The testing philosophy (based on minimal interruptions) and the star-test method are explained and illustrated with diagrams, and the test procedures are examined, including modem tests, electrical-path-length equalization, RF/IF downchain tests, protocol tests, nontransmitting protocol tests, IF/RF upchain tests, transmitting protocol tests, baseband tests, and orderwire lineups. The fundamental access discipline of the TDMA system is presented in an appendix.

Optimal Power Allocation for Downstream xDSL With Per-Modem Total Power Constraints: Broadcast Channel Optimal Spectrum Balancing (BC-OSB)

NASA Astrophysics Data System (ADS)

Le Nir, Vincent; Moonen, Marc; Verlinden, Jan; Guenach, Mamoun

2009-02-01

Recently, the duality between Multiple Input Multiple Output (MIMO) Multiple Access Channels (MAC) and MIMO Broadcast Channels (BC) has been established under a total power constraint. The same set of rates for MAC can be achieved in BC exploiting the MAC-BC duality formulas while preserving the total power constraint. In this paper, we describe the BC optimal power allo- cation applying this duality in a downstream x-Digital Subscriber Lines (xDSL) context under a total power constraint for all modems over all tones. Then, a new algorithm called BC-Optimal Spectrum Balancing (BC-OSB) is devised for a more realistic power allocation under per-modem total power constraints. The capacity region of the primal BC problem under per-modem total power constraints is found by the dual optimization problem for the BC under per-modem total power constraints which can be rewritten as a dual optimization problem in the MAC by means of a precoder matrix based on the Lagrange multipliers. We show that the duality gap between the two problems is zero. The multi-user power allocation problem has been solved for interference channels and MAC using the OSB algorithm. In this paper we solve the problem of multi-user power allocation for the BC case using the OSB algorithm as well and we derive a computational efficient algorithm that will be referred to as BC-OSB. Simulation results are provided for two VDSL2 scenarios: the first one with Differential-Mode (DM) transmission only and the second one with both DM and Phantom- Mode (PM) transmissions.

PV-Diesel Hybrid SCADA Experiment Network Design

NASA Technical Reports Server (NTRS)

Kalu, Alex; Durand, S.; Emrich, Carol; Ventre, G.; Wilson, W.; Acosta, R.

1999-01-01

The essential features of an experimental network for renewable power system satellite based supervisory, control and data acquisition (SCADA) are communication links, controllers, diagnostic equipment and a hybrid power system. Required components for implementing the network consist of two satellite ground stations, to satellite modems, two 486 PCs, two telephone receivers, two telephone modems, two analog telephone lines, one digital telephone line, a hybrid-power system equipped with controller and a satellite spacecraft. In the technology verification experiment (TVE) conducted by Savannah State University and Florida Solar Energy Center, the renewable energy hybrid system is the Apex-1000 Mini-Hybrid which is equipped with NGC3188 for user interface and remote control and the NGC2010 for monitoring and basic control tasks. This power system is connected to a satellite modem via a smart interface, RS232. Commands are sent to the power system control unit through a control PC designed as PC1. PC1 is thus connected to a satellite model through RS232. A second PC, designated PC2, the diagnostic PC is connected to both satellite modems via separate analog telephone lines for checking modems'health. PC2 is also connected to PC1 via a telephone line. Due to the unavailability of a second ground station for the ACTS, one ground station is used to serve both the sending and receiving functions in this experiment. Signal is sent from the control PC to the Hybrid system at a frequency f(sub 1), different from f(sub 2), the signal from the hybrid system to the control PC. f(sub l) and f(sub 2) are sufficiently separated to avoid interference.

[Analysis of supplying situation in pharmacies. I. Supply with medicaments and health appliances from the viewpoint of pharmacies and distributors].

PubMed

Macesková, B; Vyhnalíková, J

2007-01-01

The paper describes the contemporary methods of ordering, their demands for time, and positive and negative aspects. The results of the analysis of the data from pharmacies were compared with the data found by analyzing the data provided by the distributor. The methodology of the paper includes: a questionnaire survey, the method of the autopicture, and an analysis of archival data from pharmacies and distributors. The most frequent response to the question concerning the number of supplying wholesale distributors is two (38.1% of pharmacies) and three (33.3 % of pharmacies); pharmacies receive supplies from them most frequently three times a day (28.1% of pharmacies). 61.9 % of pharmacies compile the orders intuitively, 38.1% of them use the possibilities of the automatic proposal of the order using a PC system. 66.6% of pharmacies utilize modem ordering whose advantages are rapidity (493%), time availability (41.2%), a list of confirmed preparations (28.5 %), and financial advantageousness (23.8 %). The average time of ordering amounts to 21 min a day for telephone orders and 4 min a day for modem orders, the average proportion in the use of the individual methods of ordering is 59.1% to 40.9% of items to the benefit of modem orders. A concrete pharmacy was selected to demonstrate the effect of changes resulting from the transition from exclusively telephonic ordering to prevalently modem ordering; saved time period amounted to 62.5 % (from 14.4 s to 5.4 s per 1 ordered item). The analysis of distributors' data reveals an increase in the share of the items and packages ordered via modem (from 22.2%, and 20.6%, respectively, in the year 2000, to 54.5% and 49.8%, respectively, in the year 2004).

NASA. Lewis Research Center Advanced Modulation and Coding Project: Introduction and overview

NASA Technical Reports Server (NTRS)

Budinger, James M.

1992-01-01

The Advanced Modulation and Coding Project at LeRC is sponsored by the Office of Space Science and Applications, Communications Division, Code EC, at NASA Headquarters and conducted by the Digital Systems Technology Branch of the Space Electronics Division. Advanced Modulation and Coding is one of three focused technology development projects within the branch's overall Processing and Switching Program. The program consists of industry contracts for developing proof-of-concept (POC) and demonstration model hardware, university grants for analyzing advanced techniques, and in-house integration and testing of performance verification and systems evaluation. The Advanced Modulation and Coding Project is broken into five elements: (1) bandwidth- and power-efficient modems; (2) high-speed codecs; (3) digital modems; (4) multichannel demodulators; and (5) very high-data-rate modems. At least one contract and one grant were awarded for each element.

Remote sensing of tropospheric gases and aerosols with airborne DIAL system

NASA Technical Reports Server (NTRS)

Browell, E. V.

1983-01-01

The multipurpose airborne DIAL system developed at NASA Langley Research Center is characterized, and the published results of tropospheric O3, H2O, and aerosol-backscatter remote-sensing experiments performed in 1980 and 1981 are summarized. The system comprises two tunable dye lasers pumped by frequency-doubled Nd:YAG lasers, dielectric-coated steering optics, a 36-cm-diameter Cassegrain receiver telescope, gateable photomultiplier tubes, and a minicomputer data-processing unit for real-time calculation of gas concentrations and backscattering profiles. The transmitted energy of the 100-microsec-separated dye-laser pulses is 40, 80, or 50 mJ/pulse at around 300, 600, or 720-nm wavelength, respectively. Good agreement was found between DIAL-remote-sensed and in-situ H2O and O3 profiles of the lower troposphere and O3 profiles of the tropopause region, and the usefulness of DIAL backscattering measurements in the study of boundary-layer and tropospheric dynamics is demonstrated. The feasibility of DIAL sensing of power-plant or urban plume SO2, of urban-area (or rural-area column-content) NO2, and of temperature and H2O (simultaneously using a third laser) has been suggested by simulation studies.

FY05 FM Dial Summary Report

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

Harper, Warren W.; Strasburg, Jana D.; Golovich, Elizabeth C.

2005-12-01

Pacific Northwest National Laboratory's Infrared Sensors team is focused on developing methods for standoff detection of nuclear proliferation. In FY05, PNNL continued the development of the FM DIAL (frequency-modulated differential absorption LIDAR) experiment. Additional improvements to the FM DIAL trailer provided greater stability during field campaigns which made it easier to explore new locations for field campaigns. In addition to the Hanford Townsite, successful experiments were conducted at the Marine Science Laboratory in Sequim, WA and the Nevada Test Site located outside Las Vegas, NV. The range of chemicals that can be detected by FM DIAL has also increased. Priormore » to FY05, distributed feedback quantum cascade lasers (DFB-QCL) were used in the FM DIAL experiments. With these lasers, only simple chemicals with narrow (1-2 cm-1) absorption spectra, such as CO2 and N2O, could be detected. Fabry-Perot (FP) QC lasers have much broader spectra (20-40 cm-1) which allows for the detection of larger chemicals and a wider array of chemicals that can be detected. A FP-QCL has been characterized and used during initial studies detecting DMMP (dimethyl methylphosphonate).« less

The United States Army 1995 Modernization Plan. Force 21

DTIC Science & Technology

1995-04-06

being modified to support the requirements and new dangers of our changing times. It is often said that we study history so as not to repeat thu...intuitive sense of battle gained from study and expertise. Training remains the key to modem, combat-ready Light Forces. Effective modemization and...Devices, Simulators and Simulations (TADSS) Light Forces training is supported by the Combined Arms Training Strategy (CATS). CATS is a descriptive

Programmable rate modem utilizing digital signal processing techniques

NASA Technical Reports Server (NTRS)

Naveh, Arad

1992-01-01

The need for a Programmable Rate Digital Satellite Modem capable of supporting both burst and continuous transmission modes with either Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK) modulation is discussed. The preferred implementation technique is an all digital one which utilizes as much digital signal processing (DSP) as possible. The design trade-offs in each portion of the modulator and demodulator subsystem are outlined.

Automated Air Information Production System - Phase II.

DTIC Science & Technology

1980-10-01

Alphanumeric CRT terminals, 2 Gandalf Data Inc. Model LDS 250/3 56 Kbps synchronous short haul modems , 2 General Data Comm Industries TDM-1205 time...supplied encrypt/decrypt devices which would interface to the communications multiplexers supplied by Synectics. Synectics also supplied short haul modems ...During the development effort and throughput of the T&E period the high speed ( 56K bps) link would intermittently go out of synchronization. The problem

Demonstration of Multi-Gbps Data Rates at Ka-Band Using Software-Defined Modem and Broadband High Power Amplifier for Space Communications

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Wintucky, Edwin G.; Landon, David G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen; McIntire, William K.; Metz, John L.; Smith, Francis J.

2011-01-01

The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 W and efficiency greater than 60 percent. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10(exp -9). The presented results include a plot of the received waveform constellation, BER vs. E(sub b)/N(sub 0) and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA s payload data rate can be increased by at least an order of magnitude (greater than 10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.

High-Performance CCSDS AOS Protocol Implementation in FPGA

NASA Technical Reports Server (NTRS)

Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

2010-01-01

The Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) space data link protocol provides a framing layer between channel coding such as LDPC (low-density parity-check) and higher-layer link multiplexing protocols such as CCSDS Encapsulation Service, which is described in the following article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS AOS protocol implementation needs to be optimized to both reduce energy consumption and operate at a high rate.

Analysis of Requirements of On-Line Network Cataloging Services for Small, Academic, Public, School and Other Libraries: A Demonstration Project using the OCLC System. Final Report.

ERIC Educational Resources Information Center

Markuson, Barbara Evans

This report results from a project using the OCLC system to provide catalog services to small libraries. Alternatives described include: centralized cataloging, centralized book processing, sharing of OCLC terminals, and use of dial-up terminals. The OCLC data base was found useful for all types of small libraries. It is recommended that network…

Introduction to the concepts of TELEDEMO and TELEDIMS

NASA Technical Reports Server (NTRS)

Rice, R. F.; Schlutsmeyer, A. P.

1982-01-01

An introduction to the system concepts: TELEDEMO and TELEDIMS is provided. TELEDEMO is derived primarily from computer graphics and, via incorporation of sophisticated image data compression, enables effective low cost teleconferencing at data rates as low as 1K bit/second using dial-up phone lines. Combining TELEDEMO's powerful capabilities for the development of presentation material with microprocessor-based Information Management Systems (IMS) yields a truly all electronic IMS called TELEDIMS.

Computer Simulation of Global Profiles of Carbon Dioxide Using a Pulsed, 2-Micron, Coherent-Detection, Column-Content DIAL System

NASA Technical Reports Server (NTRS)

Kavaya, Michael J.; Singh, Upendra N.; Koch, Grady J.; Yu, Jirong; Frehlich, Rod G.

2009-01-01

We present preliminary results of computer simulations of the error in measuring carbon dioxide mixing ratio profiles from earth orbit. The simulated sensor is a pulsed, 2-micron, coherent-detection lidar alternately operating on at least two wavelengths. The simulated geometry is a nadir viewing lidar measuring the column content signal. Atmospheric absorption is modeled using FASCODE3P software with the HITRAN 2004 absorption line data base. Lidar shot accumulation is employed up to the horizontal resolution limit. Horizontal resolutions of 50, 100, and 200 km are shown. Assuming a 400 km spacecraft orbit, the horizontal resolutions correspond to measurement times of about 7, 14, and 28 s. We simulate laser pulse-pair repetition frequencies from 1 Hz to 100 kHz. The range of shot accumulation is 7 to 2.8 million pulse-pairs. The resultant error is shown as a function of horizontal resolution, laser pulse-pair repetition frequency, and laser pulse energy. The effect of different on and off pulse energies is explored. The results are compared to simulation results of others and to demonstrated 2-micron operating points at NASA Langley.

Practices, attitudes and perceptions toward road safety in yerevan, republic of armenia.

PubMed

Chekijian, Sharon Anoush; Truzyan, Nune

2012-01-01

: To determine knowledge and attitudes regarding traffic safety devices, measures, and legislation in the general population in Yerevan, Republic of Armenia. : We conducted a baseline random digit dial fixed line telephone verbal survey of Yerevan households in April 2009 with a follow-up survey in May 2010. Survey domains included restraint use, motor vehicle crash experiences, and attitudes regarding traffic safety. : In the initial survey, of 2137 numbers dialed, 436 persons were reached and 390 (90%) agreed to participate. Of survey respondents, 90% percent of household cars had seatbelts, while 47% had airbags. Twenty-four percent always or usually wore a seatbelt when driving, 21% wore a belt as a passenger. 39% were unaware of child restraints. Of the 61% who were aware of child restraints, only 32% had ever used one. A follow-up survey was conducted one year later after enforcement efforts were increased. In the follow-up survey, 81% percent always or usually wore a seatbelt when driving, and 69% wore a belt as a passenger. There was no significant increase of awareness or use of child restraints in the follow-up survey. : Although cars in Yerevan have seat belts, the majority of drivers and passengers prior to the intervention did not use them. Knowledge and use of child restraints was poor. The follow-up survey conducted after an enforcement campaign was underway in Yerevan showed that improved enforcement greatly increased awareness and compliance with current legislation. This study provides vital baseline information for the formulation of future policy. It also highlights the need for a multi-dimensional road traffic safety initiative through public educational campaigns, enforcement of current laws, and development of novel prevention policies and regulations.

Testing in Support of Space Fission System Development and Qualification

NASA Technical Reports Server (NTRS)

Houts, Mike; Bragg-Sitton, Shannon; Garber, Anne; Godfrey, Tom; Martin, Jim; Pearson, Boise; Webster, Kenny

2007-01-01

Extensive data would be required for the qualification of a fission surface power (FSP) system. The strategy for qualifying a FSP system could have a significant programmatic impact. This paper explores potential options that could be used for qualifying FSP systems, including cost-effective means for obtaining required data. three methods for obtaining qualification data are analysis, non-nuclear testing, and nuclear testing. It has been over 40 years since the US qualified a space reactor for launch. During that time, advances have been made related to all three methods. Perhaps the greatest advancement has occurred in the area of computational tools for design and analysis. Tools that have been developed, coupled with modem computers, would have a significant impact on a FSP qualification. This would be especially true for systems with materials and fuels operating well within temperature, irradiation damage, and burnup limits. The ability to perform highly realistic non-nuclear testing has also advanced throughout the past four decades. Instrumented thermal simulators were developed during the 1970s and 1980s to assist in the development, operation, and assessment of terrestrial fission systems. Instrumented thermal simulators optimized for assisting in the development, operation, and assessment of modem FSP systems have been under development (and utilized) since 1998. These thermal simulators enable heat from fission to be closely mimicked (axial power profile, radial power profile, temperature, heat flux, etc.} and extensive data to be taken from the core region. Both steady-state and transient operation can be tested. For transient testing, reactivity feedback is calculated (or measured in cold/warm criticals) based on reactor temperature and/or dimensional changes. Pin power during a transient is then calculated based on the reactivity feedback that would occur given measured values of temperature and/or dimensional change. In this way nonnuclear testing can be used to provide very realistic information related to nuclear operation. Non-nuclear testing can be used at all levels, including component, subsystem, and integrated system testing. Realistic non-nuclear testing is most useful for systems operating within known temperature, irradiation damage, and burnup capabilities.

16 CFR 1500.43a - Method of test for flashpoint of volatile flammable materials.

Code of Federal Regulations, 2012 CFR

2012-01-01

... between the temperature control dial and the thermometer readings at each major (numbered) dial division... block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a...

16 CFR 1500.43a - Method of test for flashpoint of volatile flammable materials.

Code of Federal Regulations, 2011 CFR

2011-01-01

... between the temperature control dial and the thermometer readings at each major (numbered) dial division... block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a...

16 CFR 1500.43a - Method of test for flashpoint of volatile flammable materials.

Code of Federal Regulations, 2014 CFR

2014-01-01

... between the temperature control dial and the thermometer readings at each major (numbered) dial division... block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a...

Decade of War, Volume 1. Enduring Lessons from the Past Decade of Operations

DTIC Science & Technology

2012-06-15

the incident took on political dimensions or was highlighted in the international news media .14 Conventional war features a hierarchical top-down...half of the decade. The proliferation of the internet, social media , and personal electronic devices caused the paradigm of communication to shift...unconstrained by the truth: for example, they could feed false information to the media through the use of news stringers on fast-dial from an

Atmospheric CO2 measurements with a 2-μm DIAL instrument

NASA Astrophysics Data System (ADS)

Cadiou, Erwan; Dherbecourt*, Jean-Baptiste; Gorju, Guillaume; Melkonian, Jean-Michel; Godard, Antoine; Pelon, Jacques; Raybaut, Myriam

2018-04-01

We report on ground-based atmospheric concentration measurements of carbon dioxide, using a pulsed direct detection differential absorption lidar operating at 2051 nm. The transmitter is based on a tunable parametric source emitting 10-mJ energy, 10-ns duration Fourier-limited pulses. Range resolved concentration measurements have been carried out on the aerosol back-scattered signal. Cloud signals have been used to get long range integrated-path measurements.

Design and Testing of Space Telemetry SCA Waveform

NASA Technical Reports Server (NTRS)

Mortensen, Dale J.; Handler, Louis M.; Quinn, Todd M.

2006-01-01

A Software Communications Architecture (SCA) Waveform for space telemetry is being developed at the NASA Glenn Research Center (GRC). The space telemetry waveform is implemented in a laboratory testbed consisting of general purpose processors, field programmable gate arrays (FPGAs), analog-to-digital converters (ADCs), and digital-to-analog converters (DACs). The radio hardware is integrated with an SCA Core Framework and other software development tools. The waveform design is described from both the bottom-up signal processing and top-down software component perspectives. Simulations and model-based design techniques used for signal processing subsystems are presented. Testing with legacy hardware-based modems verifies proper design implementation and dynamic waveform operations. The waveform development is part of an effort by NASA to define an open architecture for space based reconfigurable transceivers. Use of the SCA as a reference has increased understanding of software defined radio architectures. However, since space requirements put a premium on size, mass, and power, the SCA may be impractical for today s space ready technology. Specific requirements for an SCA waveform and other lessons learned from this development are discussed.

New technological developments provide deep-sea sediment density flow insights: the Monterey Coordinated Canyon Experiment

NASA Astrophysics Data System (ADS)

O'Reilly, T. C.; Kieft, B.; Chaffey, M. R.; Wolfson-Schwehr, M.; Herlien, R.; Bird, L.; Klimov, D.; Paull, C. K.; Gwiazda, R.; Lundsten, E. M.; Anderson, K.; Caress, D. W.; Sumner, E. J.; Simmons, S.; Parsons, D. R.; Talling, P.; Rosenberger, K. J.; Xu, J.; Maier, K. L.; Gales, J. A.

2017-12-01

The Monterey Coordinated Canyon Experiment (CCE) deployed an array of instruments along the Monterey Canyon floor to characterize the structure, velocity and frequency of sediment flows. CCE utilized novel technologies developed at MBARI to capture sediment flow data in unprecedented detail. 1. The Seafloor Instrument Node (SIN) at 1850 meters depth housed 3 ADCPs at 3 different frequencies, CTD, current meter, oxygen optode, fluorometer/backscatter sensor, and logged data at 10 second intervals or faster. The SIN included an acoustic modem for communication with shore through a Wave Glider relay, and provided high-resolution measurements of three flow events during three successive deployments over 1.5 years. 2. Beachball-sized Benthic Event Detectors (BEDs) were deployed on or under the seafloor to measure the characteristics of sediment density flows. Each BED recorded data from a pressure sensor and a 3-axis accelerometer and gyro to characterize motions during transport events (e.g. tumble vs rotation). An acoustic modem capable of operating through more than a meter of sediment enabled communications with a ship or autonomous surface vehicle. Multiple BEDs were deployed at various depths in the canyon during CCE, detecting and measuring many transport events; one BED moved 9 km down canyon in 50 minutes during one event. 3. Wave Glider Hot Spot (HS), equipped with acoustic and RF modems, acted as data relay between SIN, BEDs and shore, and acoustically located BEDs after sediment density flows.. In some cases HS relayed BED motion data to shore within a few hours of the event. HS provided an acoustic console to the SIN, allowing shore-based users to check SIN health and status, perform maintenance, etc. 4. Mapping operations were conducted 4 times at the SIN site to quantify depositional and erosional patterns, utilizing a prototype ultra-high-resolution mapping system on the ROV Doc Ricketts. The system consists of a 400-kHz Reson 7125 multibeam sonar, a 3DatDepth SL1 subsea LiIDAR, two stereo color cameras, and a Kearfott SeaDevil INS. At a survey altitude of 3 m above the bed, the mapping system provides 5-cm resolution multibeam bathymetry, 1-cm resolution lidar bathymetry, and 2-mm resolution photomosaics. We will describe the design and full capabilities of these novel systems.

Blue Flag Distributed Wargaming System

DTIC Science & Technology

1992-07-01

combat simulation , and multi- site video teleconferencing (VTC). The Warrior Flag 90 feasibility demonstration was sponsored by the 4441st Tactical...provide RS-422 cross patching, loop -back and test points. At the hub six CSUs and two fiber optic modems were cabled in the normal-thru configuration...spare crypto or the fiber optic modem may be placed on-line via a patch. Loop plugs were provided for testing. Clock switches were provided to switch

Coherent Path Beamformer Front End for High Performance Acoustic Modems

DTIC Science & Technology

1999-09-30

transmission underwater. This knowledge will be used to develop a test model for evaluating under water acoustic modem and other shallow water sonar ...rates can be achieved, as shown in the following two sections. WORK COMPLETED Two systems have been developed in the Sonar Laboratory of Ocean...2) More performant variable gain preamplifiers have been installed and the software updated for a better control of the dynamic range. 3) An

DDN (Defense Data Network) Protocol Implementations and Vendors Guide,

DTIC Science & Technology

1988-02-01

TELNET) TCP/IP on an ethernet network. The program simulates a Hayes modem through the serial port. BWFTP is a thorough implementation of the FTP...25 IMP interface at VV from 19.2 Kbps to 56K bps. The IP, ICMP, TCP, Telnet. FFP and SMTP protocols are implemented along with R-Utxities...WANs. microcomputers, dataswitches. minicomputers. "black boxes" and modems . DOCUMENTATION: Software System Overview, Generic X.25 Porting Guide

Performance evaluation of a mobile satellite system modem using an ALE method

NASA Technical Reports Server (NTRS)

Ohsawa, Tomoki; Iwasaki, Motoya

1990-01-01

Experimental performance of a newly designed demodulation concept is presented. This concept applies an Adaptive Line Enhancer (ALE) to a carrier recovery circuit, which makes pull-in time significantly shorter in noisy and large carrier offset conditions. This new demodulation concept was actually developed as an INMARSAT standard-C modem, and was evaluated. On a performance evaluation, 50 symbol pull-in time is confirmed under 4 dB Eb/No condition.

Age of ground water in basalt aquifers near Spring Creek National Fish Hatchery, Skamania County, Washington

USGS Publications Warehouse

Hinkle, Stephen R.

1996-01-01

A comparison of CFC data with both adjusted and unadjusted 14C data suggests that water discharging at the hatchery springs contains a mixture of modem and old water, where old water is defined as water recharged prior to 1944. The CFC data support a component of modem water, whereas the 14C data suggest a component of old water. Similar results were obtained from a comparison of CFC data with adjusted and unadjusted 14C data for water collected from Well 3. Well 3 is north of the hatchery springs, on a flow path that appears to be parallel to and similar in length to the flow path leading to the hatchery springs. Water from the Hatchery Well, however, may be devoid of modem water and appears to have an overall age on the order of thousands of years.

A Powerful Antidote, a Strange Camel and Turkish Pepper: Iberian Science, the Discovery of the New World and the Early Modem Czech Lands.

PubMed

Cerna, Jana

2016-08-01

This article analyses the reception of knowledge about new world nature, and, more specifically, the reception of Iberian scientific knowledge of nature in the Americas, in the early modem Czech lands. It shows how the process of the reception of information about nature in the new world differed among the urban classes, intellectuals and the nobility; particular attention is paid to herbals, cosmographical works and travel reports. On the one hand, the study reveals that the efforts of Central European intellectuals to interpret new world nature were limited by the lack of necessary data and experience, which led to some misinterpretations and simplifications. On the other hand, it shows these Central European scholars to be fully-fledged members of an information network, whose works share many of the same characteristics as Iberian and, in general, early modem European science.

A Compact Mobile Ozone Lidar for Atmospheric Ozone and Aerosol Profiling

NASA Technical Reports Server (NTRS)

De Young, Russell; Carrion, William; Pliutau, Denis

2014-01-01

A compact mobile differential absorption lidar (DIAL) system has been developed at NASA Langley Research Center to provide ozone, aerosol and cloud atmospheric measurements in a mobile trailer for ground-based atmospheric ozone air quality campaigns. This lidar is integrated into the Tropospheric Ozone Lidar Network (TOLNet) currently made up of four other ozone lidars across the country. The lidar system consists of a UV and green laser transmitter, a telescope and an optical signal receiver with associated Licel photon counting and analog channels. The laser transmitter consist of a Q-switched Nd:YLF inter-cavity doubled laser pumping a Ce:LiCAF tunable UV laser with all the associated power and lidar control support units on a single system rack. The system has been configured to enable mobile operation from a trailer and was deployed to Denver, CO July 15-August 15, 2014 supporting the DISCOVER-AQ campaign. Ozone curtain plots and the resulting science are presented.

16 CFR § 1500.43a - Method of test for flashpoint of volatile flammable materials.

Code of Federal Regulations, 2013 CFR

2013-01-01

... between the temperature control dial and the thermometer readings at each major (numbered) dial division... block of suitable conductivity with a cylindrical depression, or sample cup, over which is fitted a...

Tunable lasers for water vapor measurements and other lidar applications

NASA Technical Reports Server (NTRS)

Gammon, R. W.; Mcilrath, T. J.; Wilkerson, T. D.

1977-01-01

A tunable dye laser suitable for differential absorption (DIAL) measurements of water vapor in the troposphere was constructed. A multi-pass absorption cell for calibration was also constructed for use in atmospheric DIAL measurements of water vapor.

Tropospheric ozone profiles by DIAL at Maïdo Observatory (Reunion Island): system description, instrumental performance and result comparison with ozone external data set

NASA Astrophysics Data System (ADS)

Duflot, Valentin; Baray, Jean-Luc; Payen, Guillaume; Marquestaut, Nicolas; Posny, Francoise; Metzger, Jean-Marc; Langerock, Bavo; Vigouroux, Corinne; Hadji-Lazaro, Juliette; Portafaix, Thierry; De Mazière, Martine; Coheur, Pierre-Francois; Clerbaux, Cathy; Cammas, Jean-Pierre

2017-09-01

In order to recognize the importance of ozone (O3) in the troposphere and lower stratosphere in the tropics, a DIAL (differential absorption lidar) tropospheric O3 lidar system (LIO3TUR) was developed and installed at the Université de la Réunion campus site (close to the sea) on Reunion Island (southern tropics) in 1998. From 1998 to 2010, it acquired 427 O3 profiles from the low to the upper troposphere and has been central to several studies. In 2012, the system was moved up to the new Maïdo Observatory facility (2160 m a.m.s.l. - metres above mean sea level) where it started operation in February 2013. The current system (LIO3T) configuration generates a 266 nm beam obtained with the fourth harmonic of a Nd:YAG laser sent into a Raman cell filled up with deuterium (using helium as buffer gas), generating the 289 and 316 nm beams to enable the use of the DIAL method for O3 profile measurements. The optimal range for the actual system is 6-19 km a.m.s.l., depending on the instrumental and atmospheric conditions. For a 1 h integration time, vertical resolution varies from 0.7 km at 6 km a.m.s.l. to 1.3 km at 19 km a.m.s.l., and mean uncertainty within the 6-19 km range is between 6 and 13 %. Comparisons with eight electrochemical concentration cell (ECC) sondes simultaneously launched from the Maïdo Observatory show good agreement between data sets with a 6.8 % mean absolute relative difference (D) between 6 and 17 km a.m.s.l. (LIO3T lower than ECC). Comparisons with 37 ECC sondes launched from the nearby Gillot site during the daytime in a ±24 h window around lidar shooting result in a 9.4 % D between 6 and 19 km a.m.s.l. (LIO3T lower than ECC). Comparisons with 11 ground-based Network for Detection of Atmospheric Composition Change (NDACC) Fourier transform infrared (FTIR) spectrometer measurements acquired during the daytime in a ±24 h window around lidar shooting show good agreement between data sets with a D of 11.8 % for the 8.5-16 km partial column (LIO3T higher than FTIR), and comparisons with 39 simultaneous Infrared Atmospheric Sounding Interferometer (IASI) observations over Reunion Island show good agreement between data sets with a D of 11.3 % for the 6-16 km partial column (LIO3T higher than IASI). ECC, LIO3TUR and LIO3T O3 monthly climatologies all exhibit the same range of values and patterns. In particular, the Southern Hemisphere biomass burning seasonal enhancement and the ozonopause altitude decrease in late austral winter-spring, as well as the sign of deep convection bringing boundary layer O3-poor air masses up to the middle-upper troposphere in late austral summer, are clearly visible in all data sets.

Improvement of the matching speed of AIMS for development of an automatic totally tuning system for hyperthermia treatment using a resonant cavity applicator.

PubMed

Shindo, Y; Kato, K; Tsuchiya, K; Hirashima, T; Suzuki, M

2009-01-01

In this paper, we discuss the improvement of the speed of AIMS (Automatic Impedance Matching System) to automatically make impedance matching for a re-entrant resonant cavity applicator for non-invasive deep brain tumors hyperthermia treatments. We have already discussed the effectiveness of the heating method using the AIMS, with experiments of heating agar phantoms. However, the operating time of AIMS was about 30 minutes. To develop the ATT System (Automatic Totally Tuning System) including the automatic frequency tuning system, we must improve this problem. Because, when using the ATTS, the AIMS is used repeatedly to find the resonant frequency. In order to improve the speed of impedance matching, we developed the new automatic impedance matching system program (AIMS2). In AIMS, the stepping motors were connected to the impedance matching unit's dials. These dials were turned to reduce the reflected power. AIMS consists of two phases: all range searching and detailed searching. We focused on the three factors affecting the operating speed and improved them. The first factor is the interval put between the turning of the motors and AD converter. The second factor is how the steps of the motor when operating all range searching. The third factor is the starting position of the motor when detail searching. We developed the simple ATT System (ATT-beta) based on the AIMS2. To evaluate the developed AIMS2 and ATT- beta, experiments with an agar phantom were performed. From these results, we found that the operating time of the AIMS2 is about 4 minutes, which was approximately 12% of AIMS. From ATT-beta results, it was shown that it is possible to tune frequency and automatically match impedance with the program based on the AIMS2.

Autonomous dial-a-ride transit. Part 1, technical overview

DOT National Transportation Integrated Search

1998-11-01

Is autonomous-dial-a-ride (ADART) and idea whose time has come with the advent of technologies. This report describes the essential features of an experimental ADART service and establishes a context for ADART implementation based on urban transit in...

Plate Boundary Observatory GPS Network Status in California

NASA Astrophysics Data System (ADS)

Walls, C. P.; Austin, K. E.; Dittman, T.; Mann, D.; Basset, A.; Turner, R.; Lawrence, S.; Woolace, A. C.; Kasmer, D.; Hodgkinson, K. M.; Feaux, K.; Mattioli, G. S.

2015-12-01

The EarthScope PBO GPS network, funded by the NSF and operated by UNAVCO, is comprised of 599 permanent GPS stations spanning three principal tectonic regimes and is administered by separate management regions (Subduction - Pacific Northwest [91 sites], Extension - East [41 sites], Transform - Southwest [467 sites]). Since the close of construction in September 2008 various enhancements have been implemented through additional funding by the NSF, NOAA, and NASA and in collaboration with stakeholders such as Caltrans, Scripps, and the USGS. Initially, the majority of stations used first generation IP based cellular modems and radios capable of ~10KB/s data rates. The bandwidth limitation was a challenge for regional high-rate data downloads for GPS-seismology and airborne LiDAR surveys, and real-time data flow. Today, only 13 of the original cell modems remain with 297 upgraded cell modems providing 3G/4G/LTE data communications with transfer rates ranging from 80-400 KB/s. Ongoing radio network expansion and upgrades continue to harden communications. 32 VSAT and one manual download site remain. In CA, the network capabilities for 1Hz and 5Hz downloads or real-time streaming are ~95%, ~80% and ~65%, respectively. During the past year, uptime ranged from 94-99% with data return for 15 s data exceeding 99%. Real-time (1 Hz) data from 204 sites are distributed in BINEX and RTCM 2.3/3.1 formats with an average latency of 0.5 s and completion of 86%. A variety of geophysical sensors are co-located with the GPS stations and include: 21 MEMS accelerometers, 31 strong motion and broadband seismometers, 9 borehole strainmeters and 1 long baseline strainmeter. Vaisala meteorological instruments are located at 60 sites of which 38 stream GPS/Met data. In an effort to modernize the network, Trimble NetRS receivers are gradually being replaced with GNSS-capable/enabled receivers and antennas. Today, 11 stations are GLONASS enabled and 84 are GNSS capable.

Use of the 'real-ear to dial difference' to derive real-ear SPL from hearing level obtained with insert earphones.

PubMed

Munro, K J; Lazenby, A

2001-10-01

The electroacoustic characteristics of a hearing instrument are normally selected for individuals using data obtained during audiological assessment. The precise inter-relationship between the electroacoustic and audiometric variables is most readily appreciated when they have been measured at the same reference point, such as the tympanic membrane. However, it is not always possible to obtain the real-ear sound pressure level (SPL) directly if this is below the noise floor of the probe-tube microphone system or if the subject is unco-operative. The real-ear SPL may be derived by adding the subject's real-ear to dial difference (REDD) acoustic transform to the audiometer dial setting. The aim of the present study was to confirm the validity of the Audioscan RM500 to measure the REDD with the ER-3A insert earphone. A probe-tube microphone was used to measure the real-ear SPL and REDD from the right ears of 16 adult subjects ranging in age from 22 to 41 years (mean age 27 years). Measurements were made from 0.25 kHz to 6 kHz at a dial setting of 70 dB with an ER-3A insert earphone and two earmould configurations: the EAR-LINK foam ear-tip and the subjects' customized skeleton earmoulds. Mean REDD varied as a function of frequency but was typically approximately 12 dB with a standard deviation (SD) of +/- 1.7 dB and +/- 2.7 dB for the foam ear-tip and customized earmould, respectively. The mean test-retest difference of the REDD varied with frequency but was typically 0.5 dB (SD 1 dB). Over the frequency range 0.5-4 kHz, the derived values were found to be within 5 dB of the measured values in 95% of subjects when using the EAR-LINK foam ear-tip and within 4 dB when using the skeleton earmould. The individually measured REDD transform can be used in clinical practice to derive a valid estimate of real-ear SPL when it has not been possible to measure this directly.

Advanced Water Vapor Lidar Detection System

NASA Technical Reports Server (NTRS)

Elsayed-Ali, Hani

1998-01-01

In the present water vapor lidar system, the detected signal is sent over long cables to a waveform digitizer in a CAMAC crate. This has the disadvantage of transmitting analog signals for a relatively long distance, which is subjected to pickup noise, leading to a decrease in the signal to noise ratio. Generally, errors in the measurement of water vapor with the DIAL method arise from both random and systematic sources. Systematic errors in DIAL measurements are caused by both atmospheric and instrumentation effects. The selection of the on-line alexandrite laser with a narrow linewidth, suitable intensity and high spectral purity, and its operation at the center of the water vapor lines, ensures minimum influence in the DIAL measurement that are caused by the laser spectral distribution and avoid system overloads. Random errors are caused by noise in the detected signal. Variability of the photon statistics in the lidar return signal, noise resulting from detector dark current, and noise in the background signal are the main sources of random error. This type of error can be minimized by maximizing the signal to noise ratio. The increase in the signal to noise ratio can be achieved by several ways. One way is to increase the laser pulse energy, by increasing its amplitude or the pulse repetition rate. Another way, is to use a detector system with higher quantum efficiency and lower noise, on the other hand, the selection of a narrow band optical filter that rejects most of the day background light and retains high optical efficiency is an important issue. Following acquisition of the lidar data, we minimize random errors in the DIAL measurement by averaging the data, but this will result in the reduction of the vertical and horizontal resolutions. Thus, a trade off is necessary to achieve a balance between the spatial resolution and the measurement precision. Therefore, the main goal of this research effort is to increase the signal to noise ratio by a factor of 10 over the current system, using a newly evaluated, very low noise avalanche photo diode detector and constructing a 10 MHz waveform digitizer which will replace the current CAMAC system.

Initial Development of a Metric to Describe the Level of Safety Associated with Piloting an Aircraft with Synthetic Vision Systems (SVS) Displays

NASA Technical Reports Server (NTRS)

Bartolone, Anthony P.; Glabb, Louis J.; Hughes, Monica F.; Parrish, Russell V.

2005-01-01

Synthetic Vision Systems (SVS) displays provide pilots with a continuous view of terrain combined with integrated guidance symbology in an effort to increase situation awareness (SA) and decrease workload during operations in Instrument Meteorological Conditions (IMC). It is hypothesized that SVS displays can replicate the safety and operational flexibility of flight in Visual Meteorological Conditions (VMC), regardless of actual out-the-window (OTW) visibility or time of day. Significant progress has been made towards evolving SVS displays as well as demonstrating their ability to increase SA compared to conventional avionics in a variety of conditions. While a substantial amount of data has been accumulated demonstrating the capabilities of SVS displays, the ability of SVS to replicate the safety and operational flexibility of VMC flight performance in all visibility conditions is unknown to any specific degree. In order to more fully quantify the relationship of flight operations in IMC with SVS displays to conventional operations conducted in VMC, a fundamental comparison to current day general aviation (GA) flight instruments was warranted. Such a comparison could begin to establish the extent to which SVS display concepts are capable of maintaining an "equivalent level of safety" with the round dials they could one day replace, for both current and future operations. A combination of subjective and objective data measures were used to quantify the relationship between selected components of safety that are associated with flying an approach. Four information display methods ranging from a "round dials" baseline through a fully integrated SVS package that includes terrain, pathway based guidance, and a strategic navigation display, were investigated in this high fidelity simulation experiment. In addition, a broad spectrum of pilots, representative of the GA population, were employed for testing in an attempt to enable greater application of the results and determine if "equivalent levels of safety" are achievable through the incorporation of SVS technology regardless of a pilot's flight experience.

Atmospheric remote sensing of water vapor, HCl and CH4 using a continuously tunable Co:MgF2 laser

NASA Technical Reports Server (NTRS)

Menyuk, Norman; Killinger, Dennis K.

1987-01-01

A differential-absorption lidar system has been developed which uses a continuously tunable (1.5-2.3 micron) cobalt-doped magnesium fluoride laser as the radiation source. Preliminary atmospheric measurements of water vapor, HCl, and CH4 have been made with this system, including both path-averaged and ranged-resolved DIAL measurements at ranges up to 6 and 3 km, respectively.

Iridium: Global OTH data communications for high altitude scientific ballooning

NASA Astrophysics Data System (ADS)

Denney, A.

While the scientific community is no stranger to embracing commercially available technologies, the growth and availability of truly affordable cutting edge technologies is opening the door to an entirely new means of global communications. For many years high altitude ballooning has provided science an alternative to costly satellite based experimental platforms. As with any project, evolution becomes an integral part of development. Specifically in the NSBF ballooning program, where flight durations have evolved from the earlier days of hours to several weeks and plans are underway to provide missions up to 100 days. Addressing increased flight durations, the harsh operational environment, along with cumbersome and outdated systems used on existing systems, such as the balloon vehicles Support Instrumentation Package (SIP) and ground-based systems, a new Over-The-Horizon (OTH) communications medium is sought. Current OTH equipment planning to be phased-out include: HF commanding systems, ARGOS PTT telemetry downlinks and INMARSAT data terminals. Other aspects up for review in addition to the SIP to utilize this communications medium include pathfinder balloon platforms - thereby, adding commanding abilities and increased data rates, plus providing a package for ultra-small experiments to ride aloft. Existing communication systems employed by the National Scientific Balloon Facility ballooning program have been limited not only by increased cost, slow data rates and "special government use only" services such as TDRSS (Tracking and Data Relay Satellite System), but have had to make special provisions to geographical flight location. Development of the Support Instrumentation Packages whether LDB (Long Duration Balloon), ULDB (Ultra Long Duration Balloon) or conventional ballooning have been plagued by non-standard systems configurations requiring additional support equipment for different regions and missions along with a myriad of backup for redundancy. Several beneficial points provided by the Iridium platform include pure global accessibility (as well as polar), cost effectiveness because it is available as a COTS (Commercially Off The Shelf) technology, reliability in that the equipment must operate in extreme conditions (near space), integration and development time into current systems must be minimized. As a bonus Motorola and NAL Research Corporation are developing SBD (Short Burst Data) into the Iridium network. This may lead the way to a global IP (Internet Protocol) node based ballooning platform. The Iridium satellite data modems employ the Iridium Low-Earth Orbit (LEO) satellite network. The scope of this paper is to introduce an OTH communications alternative, albeit not necessarily a primary one, to existing ballooning platforms using COTS based emerging technologies. Design aspects, characteristics, actual flight testing statistics, principles of the Iridium modems and communication paths are described including payload and support instrumentation interfacing. Not limited to high altitude ballooning, the Iridium communications platform opens a new era in remote commanding and data retrieval.

Technical Issues in Evolving to Integrated Services Digital Network (ISDN)

DTIC Science & Technology

1991-06-01

channel through some Page 13 Technical Issues in Evolving to ISDN Final Report separate interface (such as the AT command set of the Hayes modems or the...errors experienced over standard modem provided connectivity. But, in this project connectivity has been established only over a single CO. Those...examined to some extent and are discussed below. Existing equipment was of two types: that which treats ISDN as just another leased line providing 56k or

47 CFR 68.318 - Additional limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Conditions for Terminal Equipment Approval § 68.318 Additional... incorporate the specified features. (b) Registered terminal equipment with automatic dialing capability. (1... proceeding to dial another number. (6) Network addressing signals shall be transmitted no earlier than: (i...

47 CFR 68.318 - Additional limitations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Conditions for Terminal Equipment Approval § 68.318 Additional... incorporate the specified features. (b) Registered terminal equipment with automatic dialing capability. (1... proceeding to dial another number. (6) Network addressing signals shall be transmitted no earlier than: (i...

47 CFR 68.318 - Additional limitations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Conditions for Terminal Equipment Approval § 68.318 Additional... incorporate the specified features. (b) Registered terminal equipment with automatic dialing capability. (1... proceeding to dial another number. (6) Network addressing signals shall be transmitted no earlier than: (i...

47 CFR 68.318 - Additional limitations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Conditions for Terminal Equipment Approval § 68.318 Additional... incorporate the specified features. (b) Registered terminal equipment with automatic dialing capability. (1... proceeding to dial another number. (6) Network addressing signals shall be transmitted no earlier than: (i...

47 CFR 68.318 - Additional limitations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Conditions for Terminal Equipment Approval § 68.318 Additional... incorporate the specified features. (b) Registered terminal equipment with automatic dialing capability. (1... proceeding to dial another number. (6) Network addressing signals shall be transmitted no earlier than: (i...

Swords & Plowshares: Modifications to the MLRS Family of Munitions

DTIC Science & Technology

2013-04-01

of Dynamic Security (Washington, DC: Infantry Journal Press, 1949), 3. 23 Possony, x. 24 Richard G. Davis, The 31 Initiatives: A Study in Air...York: Dial Press / James Wade, 1979), 40. 28 Andrew G.B. Vallance , The Air Weapon: Doctrines of Air Power Strategy and Operational Art (New York, NY...AL: Air University Press, 1989), 479. 31 Ibid., 480. 32 Richard H. Van Atta and Michael J. Lippitz, Transformation and Transition: DARPA’s Role

Does Talking on a Cell Phone, With a Passenger, or Dialing Affect Driving Performance? An Updated Systematic Review and Meta-Analysis of Experimental Studies.

PubMed

Caird, Jeff K; Simmons, Sarah M; Wiley, Katelyn; Johnston, Kate A; Horrey, William J

2018-02-01

Objective An up-to-date meta-analysis of experimental research on talking and driving is needed to provide a comprehensive, empirical, and credible basis for policy, legislation, countermeasures, and future research. Background The effects of cell, mobile, and smart phone use on driving safety continues to be a contentious societal issue. Method All available studies that measured the effects of cell phone use on driving were identified through a variety of search methods and databases. A total of 93 studies containing 106 experiments met the inclusion criteria. Coded independent variables included conversation target (handheld, hands-free, and passenger), setting (laboratory, simulation, or on road), and conversation type (natural, cognitive task, and dialing). Coded dependent variables included reaction time, stimulus detection, lane positioning, speed, headway, eye movements, and collisions. Results The overall sample had 4,382 participants, with driver ages ranging from 14 to 84 years ( M = 25.5, SD = 5.2). Conversation on a handheld or hands-free phone resulted in performance costs when compared with baseline driving for reaction time, stimulus detection, and collisions. Passenger conversation had a similar pattern of effect sizes. Dialing while driving had large performance costs for many variables. Conclusion This meta-analysis found that cell phone and passenger conversation produced moderate performance costs. Drivers minimally compensated while conversing on a cell phone by increasing headway or reducing speed. A number of additional meta-analytic questions are discussed. Application The results can be used to guide legislation, policy, countermeasures, and future research.

A report of work activities on the NASA Spacelink public electronic library

NASA Technical Reports Server (NTRS)

Smith, Willard A.

1994-01-01

NASA Spacelink is a comprehensive electronic data base of NASA and other source educational and informational materials. This service originates at Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This is an education service of NASA Headquarters, through the MSFC Education Office, that first began in February of 1988. The new NASA Spacelink Public Electronic Library was the result of a study conducted to investigate an upgrade or redesign of the original NASA Spacelink. The UNIX Operating System was chosen to be the host operating system for the new NASA Spacelink Public Electronic Library. The UNIX system was selected for this project because of the strengths built into the embedded communication system and for its simple and direct file handling capabilities. The host hardware of the new system is a Sun Microsystems SPARCserver 1000 computer system. The configuration has four 50-MHz SuperSPARC processors with 128 megabytes of shared memory; three SB800 serial ports allowing 24 cable links for phone communications; 4.1 gigabytes of on-line disk storage; and ten (10) CD-ROM drives. Communications devices on the system are sufficient to support the expected number of users through the Internet, the local dial services, long distance dial services; the MSFC PABX, and the NPSS (NASA Packet Switching System) and 1-800 access service for the registered teachers.

Simultaneous Measurements of CO2 Concentration and Temperature profiles using 1.6 μm DIAL in the Lower-Atmosphere

NASA Astrophysics Data System (ADS)

Shibata, Y.; Nagasawa, C.; Abo, M.

2016-12-01

High-accurate vertical carbon dioxide (CO2) profiles are highly desirable in the inverse method to improve quantification and understanding of the global sink and source of CO2, and also global climate change. We have developed a ground based 1.6μm differential absorption lidar (DIAL) to achieve measurements of vertical CO2 profiles in the atmosphere. As the spectra of absorption lines of any molecules are influenced basically by the temperature and pressure in the atmosphere, it is important to measure them simultaneously so that the better accuracy of the DIAL measurement is realized. The barometric formula can derive atmospheric pressure of each altitude using atmospheric pressure of ground level at the lidar site. Comparison of atmospheric pressure prlofiles calculated from this equation and those obtained from radiosonde observations at Tateno, Japan are consisted within 0.2 % below 3 km altitude. So, we have developed a 1.6 μm CO2 DIAL system for simultaneous measurements of the CO2 concentration and temperature profiles in the lower-atmosphere. Laser beams of three wavelengths around a CO2 absorption spectrum is transmitted alternately to the atmosphere. Moreover, the value of the retrieved CO2 concentration will be improved remarkably by processing the iteration assignment of CO2 concentration and temperature, which measured by these DIAL techniques. We have acheived vertical CO2 concentration and temperature profile from 0.5 to 2.0 km altitude by this DIAL system. In the next step, we will use this high accuracy CO2 concentration profile and back-trajectory analysis for the behavior analysis of the CO2 mass. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency.

Precision gimballed mirror control in remote sensing LIDAR for environmental monitoring

NASA Astrophysics Data System (ADS)

Singh, Ravindra; Mudgil, Ashwani; Prakash, Chandra; Pal, Suranjan

2006-12-01

Differential Absorption Lidar (DIAL) Systems are advantageously used to detect and measure very small concentrations of trace gases in the atmosphere. There is a requirement to interrogate and search for the presence of one or more of toxic agents out of a large number (about 20 or so) of possible agents at distances up to several kilometers with the help of a ground-based multi-wavelength DIAL system employing pulsed, tunable laser sources in the wavelength bands of 2-5 micron and 9.2-10.8 micron. The Laser beams from the two sources are directed in the atmosphere with a predefined divergence to scan the atmosphere. Two methodologies can be implemented to provide the beam steering, one is to mount the entire telescope of transmitting and receiving channel on to a motorized gimbal platform and second is to keep the optical telescope stationary and use a slewing mirror to steer the beam in required direction. The first scheme is named as mass control and second scheme is called mirror control. Both the schemes have relative advantages and disadvantages and in the present DIAL application second scheme is being adopted. The present opto-mechanical configuration of DIAL system employs a 700 x 500 mm 2 (Elliptical) steering mirror for transmitting the collimated beams in a required direction and receiving the reflected beam as well. In the receiving channel a Telescope is used which collects the return beam and focuses the same on to a detector. The slewing mirror is housed in a gimbal mount having a sufficient FOR (Field of Regard) in Azimuth and elevation plane. The paper describes the modeling and simulation of Opto-mechanical and servo-mechanical subsystems of precision gimbaled mirror and also discusses the issues related to design of control system. The requirement specifications in regard to field of regard, slew rates 5°/s, scanning rates 1°/s are to be met with stringent beam pointing and scanning accuracies. The design of this system is categorized as multidisciplinary problem. The design parameters obtained from opto-mechanical analysis forms the input for control system design. The design of control system is carried out using conventional design methodologies.

UV Lidar Receiver Analysis for Tropospheric Sensing of Ozone

NASA Technical Reports Server (NTRS)

Pliutau, Denis; DeYoung, Russell J.

2013-01-01

A simulation of a ground based Ultra-Violet Differential Absorption Lidar (UV-DIAL) receiver system was performed under realistic daytime conditions to understand how range and lidar performance can be improved for a given UV pulse laser energy. Calculations were also performed for an aerosol channel transmitting at 3 W. The lidar receiver simulation studies were optimized for the purpose of tropospheric ozone measurements. The transmitted lidar UV measurements were from 285 to 295 nm and the aerosol channel was 527-nm. The calculations are based on atmospheric transmission given by the HITRAN database and the Modern Era Retrospective Analysis for Research and Applications (MERRA) meteorological data. The aerosol attenuation is estimated using both the BACKSCAT 4.0 code as well as data collected during the CALIPSO mission. The lidar performance is estimated for both diffuseirradiance free cases corresponding to nighttime operation as well as the daytime diffuse scattered radiation component based on previously reported experimental data. This analysis presets calculations of the UV-DIAL receiver ozone and aerosol measurement range as a function of sky irradiance, filter bandwidth and laser transmitted UV and 527-nm energy

Dial Measurements of Free-Tropospheric Ozone Profiles in Huntsville, AL

NASA Technical Reports Server (NTRS)

Newchurch, Mike; Kuang, Shi; Burris, John; Johnson, Steve; Long, Stephanie

2008-01-01

A tropospheric ozone DIfferential Absorption Lidar (DIAL) system has been developed jointly by NASA and the University of Alabama at Huntsville (UAH). Two separated Nd:YAG pumped dye laser systems produce the laser pulses with wavelengths of 285 and 291 nm at 20 Hz frequency. The receiver is a Newtonian telescope with a 40 cm primary and a two-channel aft optics unit. The detection system currently uses photon counting to facilitate operations at the maximum achievable altitude. This lidar measures free-tropospheric ozone profiles between 4-10 km at Regional Atmospheric Profiling Laboratory for Discovery (RAPCD) in UAH campus (ASL 206 m) under both daytime and nighttime conditions. Frequent coincident ozonesonde flights and theoretical calculations provide evidence to indicate the retrieval accuracy ranges from approx.5% at 4 km to approx.60% at 10 km with 750-m vertical resolution and 30-minute integration. Three Hamamatsu 7400 PMTs and analog detection technique will be added on the current system to extend the measurement to approx.100 m above ground to monitor the PBL and lower tropospheric ozone variations.

Information Retrieval Systems Retrieved? An Alternative to Present Dial Access Systems

ERIC Educational Resources Information Center

Hofmann, Norbert

1976-01-01

The expense of a dial access information retrieval system (DIARS) is weighed against its benefits. Problems of usage and efficacy for the student are outlined. A fully automated system is proposed instead, and its cost-saving features are pointed out. (MS)

Lidar/DIAL detection of bomb factories

NASA Astrophysics Data System (ADS)

Fiorani, Luca; Puiu, Adriana; Rosa, Olga; Palucci, Antonio

2013-10-01

One of the aims of the project BONAS (BOmb factory detection by Networks of Advanced Sensors) is to develop a lidar/DIAL (differential absorption lidar) to detect precursors employed in the manufacturing of improvised explosive devices (IEDs). At first, a spectroscopic study has been carried out: the infrared (IR) gas phase spectrum of acetone, one of the more important IED precursors, has been procured from available databases and checked with cell measurements. Then, the feasibility of a lidar/DIAL for the detection of acetone vapors has been shown in laboratory, simulating the experimental conditions of a field campaign. Eventually, having in mind measurements in a real scenario, an interferent study has been performed, looking for all known compounds that share with acetone IR absorption in the spectral band selected for its detection. Possible interfering species were investigated, simulating both urban and industrial atmospheres and limits of acetone detection in both environments were identified. This study confirmed that a lidar/DIAL can detect low concentration of acetone at considerable distances.

TWSTFT Network Status in the Pacific Rim Region and Development of a New Time Transfer Modem for TWSTFT

DTIC Science & Technology

2000-01-01

32nd Annual Precise T ime and Time Interval ( P T T I ) Meeting TWSTFT NETWORK STATUS IN THE PACIFIC RIM REGION AND DEVELOPMENT OF A NEW TIME...TRANSFER MODEM FOR TWSTFT M. Imael, M. Hosokawal, Y . Hanadol, 2. Li2, P. Fisk3, Y . Nakadan4, and C. S. Liao5 ’Communications Research Laboratory...Metrology (NRLM), Japan 5Telecommunication Laboratories (TL) , Taipei, Taiwan Abstract Iko-Way Satellite Time and Frequency Transfer ( TWSTFT ) is one

Lower-free tropospheric ozone dial measurements over Athens, Greece

NASA Astrophysics Data System (ADS)

Mytilinaios, Michail; Papayannis, Alexandros; Tsaknakis, Georgios

2018-04-01

A compact ozone differential absorption lidar (DIAL) was implemented at the Laboratory of Laser Remote Sensing of the National Technical University of Athens (NTUA), in Athens, Greece. The DIAL system is based on a Nd:YAG laser emitting at 266 nm. A high-pressure Raman cell, filled with D2, was used to generate the λON and λOFF laser wavelength pairs (i.e., 266-289 nm and 289-316 nm, respectively) based on the Stimulated Raman Scattering (SRS) effect. The system was run during daytime and nighttime conditions to obtain the vertical profile of tropospheric ozone in the Planetary Boundary Layer (PBL) and the adjacent free troposphere.

Correlation of DIAL Ozone Observations with Lightning

NASA Technical Reports Server (NTRS)

Peterson, Harold; Kuang, Shi; Koshak, William; Newchurch, Michael

2014-01-01

The purpose of this project is to see whether ozone maxima measured by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, AL may be traced back to lightning events occurring 24-48 hours beforehand. The methodology is to start with lidar measurements of ozone from DIAL. The HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is then used to determine the origin of these ozone maxima 24-48 hours prior. Data from the National Lightning Detection Network (NLDN) are used to examine the presence/absence of lightning along the trajectory. This type of analysis suggests that lightning-produced NOx may be responsible for some of the ozone maxima over Huntsville.

[Photodynamic therapy of urinary bladder cancer using a chlorin based photosensitizer].

PubMed

Iagudaev, D M; Martov, A G; Sorokatyĭ, A E; Geĭnits, A V

2006-01-01

Photodynamic therapy (PDT) is a modem, low-invasive method of urinary bladder (UB) cancer treatment. PDT can induce complete or partial destruction of the tumor, reduce recurrence rate, provide assistance to elderly patients with compromised somatic status who are not radically operable. A combined technique improves the results of photodynamic therapy in patients with surface and invasive UB cancer of stage T2 because photodynamic impact affects not only the tumor but also all UB mucosa by light fiber with cylindric diffusor introduced in a silicon balloon with water. This leads to tumor destruction and a recurrence rate decrease.

10 CFR 30.15 - Certain items containing byproduct material.

Code of Federal Regulations, 2010 CFR

2010-01-01

... electrical currents. (9) Ionizing radiation measuring instruments containing, for purposes of internal... material and not exceeding the following specified levels of radiation: (i) 25 millicuries of tritium per... considered as part of the dial), (vii) The levels of radiation from hands and dials containing promethium 147...

Audiovisual signal compression: the 64/P codecs

NASA Astrophysics Data System (ADS)

Jayant, Nikil S.

1996-02-01

Video codecs operating at integral multiples of 64 kbps are well-known in visual communications technology as p * 64 systems (p equals 1 to 24). Originally developed as a class of ITU standards, these codecs have served as core technology for videoconferencing, and they have also influenced the MPEG standards for addressable video. Video compression in the above systems is provided by motion compensation followed by discrete cosine transform -- quantization of the residual signal. Notwithstanding the promise of higher bit rates in emerging generations of networks and storage devices, there is a continuing need for facile audiovisual communications over voice band and wireless modems. Consequently, video compression at bit rates lower than 64 kbps is a widely-sought capability. In particular, video codecs operating at rates in the neighborhood of 64, 32, 16, and 8 kbps seem to have great practical value, being matched respectively to the transmission capacities of basic rate ISDN (64 kbps), and voiceband modems that represent high (32 kbps), medium (16 kbps) and low- end (8 kbps) grades in current modem technology. The purpose of this talk is to describe the state of video technology at these transmission rates, without getting too literal about the specific speeds mentioned above. In other words, we expect codecs designed for non- submultiples of 64 kbps, such as 56 kbps or 19.2 kbps, as well as for sub-multiples of 64 kbps, depending on varying constraints on modem rate and the transmission rate needed for the voice-coding part of the audiovisual communications link. The MPEG-4 video standards process is a natural platform on which to examine current capabilities in sub-ISDN rate video coding, and we shall draw appropriately from this process in describing video codec performance. Inherent in this summary is a reinforcement of motion compensation and DCT as viable building blocks of video compression systems, although there is a need for improving signal quality even in the very best of these systems. In a related part of our talk, we discuss the role of preprocessing and postprocessing subsystems which serve to enhance the performance of an otherwise standard codec. Examples of these (sometimes proprietary) subsystems are automatic face-tracking prior to the coding of a head-and-shoulders scene, and adaptive postfiltering after conventional decoding, to reduce generic classes of artifacts in low bit rate video. The talk concludes with a summary of technology targets and research directions. We discuss targets in terms of four fundamental parameters of coder performance: quality, bit rate, delay and complexity; and we emphasize the need for measuring and maximizing the composite quality of the audiovisual signal. In discussing research directions, we examine progress and opportunities in two fundamental approaches for bit rate reduction: removal of statistical redundancy and reduction of perceptual irrelevancy; we speculate on the value of techniques such as analysis-by-synthesis that have proved to be quite valuable in speech coding, and we examine the prospect of integrating speech and image processing for developing next-generation technology for audiovisual communications.

Two-way satellite time transfer: Overview and recent developments

NASA Technical Reports Server (NTRS)

Dejong, Gerrit

1994-01-01

The experiment using small earth stations for transatlantic two-way satellite time transfer between the USA and Germany has had its 10th anniversary this year. Pseudo-random noise coded time signals were phase modulated and demodulated at each station using a modem. Recently, during the last two weeks of Aug. 1993, six European time laboratories have used the INTELSAT 307E satellite for line-up tests and preliminary time transfer sessions using the same type of MITREX modem. The need for a uniform format for the exchange of data was felt heavily after these sessions. This problem was foreseen and addressed in international working parties. During Apr. 1993, in Task Group 7/2 of the ITU Radiocommunication Sector, a very intense discussion has taken place about what procedure should be recommended for TWSTFT and what items the header and data lines of the resulting data fields should contain. A difficulty is that two different methods of calibration of the earth station delays exist which result in different sets of delay data to be exchanged. Further study and discussions are necessary. Also, a meeting of the CCDS Working Group on TWSTFT addressed this in Oct. 1993. The outcome of the discussions and the prospect for future developments are presented.

Ultra Small Aperture Terminal for Ka-Band SATCOM

NASA Technical Reports Server (NTRS)

Acosta, Roberto; Reinhart, Richard; Lee, Richard; Simons, Rainee

1997-01-01

An ultra small aperture terminal (USAT) at Ka-band frequency has been developed by Lewis Research Center (LeRC) for data rates up to 1.5 Mbps in the transmit mode and 40 Mbps in receive mode. The terminal consists of a 35 cm diameter offset-fed parabolic antenna which is attached to a solid state power amplifier and low noise amplifier. A single down converter is used to convert the Ka-band frequency to 70 MHz intermediate frequency (IF). A variable rate (9.6 Kbps to 10 Mbps) commercial modem with a standard RS-449/RS-232 interface is used to provide point-to-point digital services. The terminal has been demonstrated numerous times using the Advanced Communications Technology Satellite (ACTS) and the 4.5 in Link Evaluation Terminal (LET) in Cleveland. A conceptual design for an advanced terminal has also been developed. This advanced USAT utilizes Microwave Monolithic Integrated Circuit (MMIC) and flat plate array technologies. This terminal will be self contained in a single package which will include a 1 watt solid state amplifier (SSPA), low noise amplifier (LNA) and a modem card located behind the aperture of the array. The advanced USAT will be light weight, transportable, low cost and easy to point to the satellite. This paper will introduce designs for the reflector based and array based USAT's.

Accuracy and consistency of weights provided by home bathroom scales.

PubMed

Yorkin, Meredith; Spaccarotella, Kim; Martin-Biggers, Jennifer; Quick, Virginia; Byrd-Bredbenner, Carol

2013-12-17

Self-reported body weight is often used for calculation of Body Mass Index because it is easy to collect. Little is known about sources of error introduced by using bathroom scales to measure weight at home. The objective of this study was to evaluate the accuracy and consistency of digital versus dial-type bathroom scales commonly used for self-reported weight. Participants brought functioning bathroom scales (n=18 dial-type, n=43 digital-type) to a central location. Trained researchers assessed accuracy and consistency using certified calibration weights at 10 kg, 25 kg, 50 kg, 75 kg, 100 kg, and 110 kg. Data also were collected on frequency of calibration, age and floor surface beneath the scale. All participants reported using their scale on hard surface flooring. Before calibration, all digital scales displayed 0, but dial scales displayed a mean absolute initial weight of 0.95 (1.9 SD) kg. Digital scales accurately weighed test loads whereas dial-type scale weights differed significantly (p<0.05). Imprecision of dial scales was significantly greater than that of digital scales at all weights (p<0.05). Accuracy and precision did not vary by scale age. Digital home bathroom scales provide sufficiently accurate and consistent weights for public health research. Reminders to zero scales before each use may further improve accuracy of self-reported weight.

Airborne water vapor DIAL system and measurements of water and aerosol profiles

NASA Technical Reports Server (NTRS)

Higdon, Noah S.; Browell, Edward V.

1991-01-01

The Lidar Applications Group at NASA Langley Research Center has developed a differential absorption lidar (DIAL) system for the remote measurement of atmospheric water vapor (H2O) and aerosols from an aircraft. The airborne H2O DIAL system is designed for extended flights to perform mesoscale investigations of H2O and aerosol distributions. This DIAL system utilizes a Nd:YAG-laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. The dye laser has an oscillator/amplifier configuration which incorporates a grating and prism in the oscillator cavity to narrow the output linewidth to approximately 15 pm. This linewidth can be maintained over the wavelength range of 725 to 730 nm, and it is sufficiently narrow to satisfy the off-line spectral requirements. In the Alexandrite laser, three intracavity tuning elements combine to produce an output linewidth of 1.1 pm. These spectral devices include a five-plate birefringent tuner, a 1-mm thick solid etalon and a 1-cm air-spaced etalon. A wavelength stability of +/- 0.35 pm is achieved by active feedback control of the two Fabry-Perot etalons using a frequency stabilized He-Ne laser as a wavelength reference. The three tuning elements can be synchronously scanned over a 150 pm range with microprocessor-based scanning electronics. Other aspects of the DIAL system are discussed.

Remote telescope control of site testing with ASCOM

NASA Astrophysics Data System (ADS)

Ji, Kaifan; Liang, Bo; Peng, Yajie; Wang, Feng

2012-04-01

Remote telescope control is significant important for the astronomical site testing. Basing on ASCOM standard, a prototype of remote telescope control system has been implemented. In this paper, the details of the system design, both server end and client end, are introduced. We tested the prototype on a narrow-band dial-up networking and controlled a real remote telescope successfully. The result indicates that it is effective to control remote telescope and other devices with ASCOM.

Airborne 2-Micron Double-Pulsed Integrated Path Differential Absorption Lidar for Column CO2 Measurement

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Remus, Ruben G.; Fay, James J.; Reithmaier, Karl

2014-01-01

Double-pulse 2-micron lasers have been demonstrated with energy as high as 600 millijouls and up to 10 Hz repetition rate. The two laser pulses are separated by 200 microseconds and can be tuned and locked separately. Applying double-pulse laser in DIAL system enhances the CO2 measurement capability by increasing the overlap of the sampled volume between the on-line and off-line. To avoid detection complicity, integrated path differential absorption (IPDA) lidar provides higher signal-to-noise ratio measurement compared to conventional range-resolved DIAL. Rather than weak atmospheric scattering returns, IPDA rely on the much stronger hard target returns that is best suited for airborne platforms. In addition, the IPDA technique measures the total integrated column content from the instrument to the hard target but with weighting that can be tuned by the transmitter. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. Currently, NASA LaRC is developing and integrating a double-Pulsed 2-micron direct detection IPDA lidar for CO2 column measurement from an airborne platform. The presentation will describe the development of the 2-micron IPDA lidar system and present the airborne measurement of column CO2 and will compare to in-situ measurement for various ground target of different reflectivity.

Results of an Internet survey determining the most frequently used ankle scores by AOFAS members.

PubMed

Lau, Johnny T C; Mahomed, Nizar M; Schon, Lew C

2005-06-01

With technological advances in ankle arthroplasty, there has been parallel development in the outcome instruments used to assess the results of surgery. The literature recommends the use of valid, reliable, and responsive ankle scores, but the ankle scores commonly used in clinical practice remain undefined. An internet survey of members of the American Orthopaedic Foot and Ankle Society (AOFAS) was conducted to determine which three ankle scores they perceived as most commonly used in the literature, which ones they believe are validated, which ones they prefer, and which they use in practice. According to respondents, the three most commonly used scores were the AOFAS Ankle score, the Foot Function Index (FFI), and the Musculoskeletal Outcomes Data Evaluation and Management System (MODEMS). The respondents believed that the AOFAS Ankle score, FFI, and MODEMS were validated. The FFI and MODEMS are validated, but the AOFAS ankle score is not validated. Most respondents preferred using the AOFAS Ankle score. The use of the empirical AOFAS Ankle score continues among AOFAS members.

Reengineering legacy software to object-oriented systems

NASA Technical Reports Server (NTRS)

Pitman, C.; Braley, D.; Fridge, E.; Plumb, A.; Izygon, M.; Mears, B.

1994-01-01

NASA has a legacy of complex software systems that are becoming increasingly expensive to maintain. Reengineering is one approach to modemizing these systems. Object-oriented technology, other modem software engineering principles, and automated tools can be used to reengineer the systems and will help to keep maintenance costs of the modemized systems down. The Software Technology Branch at the NASA/Johnson Space Center has been developing and testing reengineering methods and tools for several years. The Software Technology Branch is currently providing training and consulting support to several large reengineering projects at JSC, including the Reusable Objects Software Environment (ROSE) project, which is reengineering the flight analysis and design system (over 2 million lines of FORTRAN code) into object-oriented C++. Many important lessons have been learned during the past years; one of these is that the design must never be allowed to diverge from the code during maintenance and enhancement. Future work on open, integrated environments to support reengineering is being actively planned.

NOAA TELEPHONE RECORDINGS

Science.gov Websites

! Boating Safety Beach Hazards Rip Currents Hypothermia Hurricanes Thunderstorms Lightning Coastal Flooding . Mariners can now hear the latest coastal and offshore weather observations using Dial-A-Buoy. Dial-A-Buoy wind and wave measurements taken within the last hour at 65 buoy and 54 Coastal-Marine Automated

[Pathogenesis of adhesions formation after intraabdominal operations].

PubMed

Voskanian, S É; Kyzlasov, P S

2011-01-01

The article describes the pathogenesis of adhesions formation after intraabdominal operations. Described predisposing factors leading of which is mechanical trauma, resulting from the use of surgical instruments, rough manipulations during surgery, damage to the mesothelium by dry gauze etc, which cause the adhesions. The pathogenesis of adhesions formation after intraabdominal surgery is presented in outline form, which described the changes occurring in the body starting with combination of predisposing factors and ending with the development of adhesions with blood vessels by 7-12 days after surgery. At the genetic level predisposition to adhesions formation and development of adhesive disease is treated as a manifestation of rapid acetylation phenotype, in which the intensity of fibrin formation exceeds normal rate of its catabolism. Thus, according to modem concepts, adhesive disease is a separate nosologic unit that dictates the necessity of its detailed study, development and introduction new universal methods of preventing the adhesions formation after intraabdominal operations.

ICC '86; Proceedings of the International Conference on Communications, Toronto, Canada, June 22-25, 1986, Conference Record. Volumes 1, 2, & 3

NASA Astrophysics Data System (ADS)

Papers are presented on ISDN, mobile radio systems and techniques for digital connectivity, centralized and distributed algorithms in computer networks, communications networks, quality assurance and impact on cost, adaptive filters in communications, the spread spectrum, signal processing, video communication techniques, and digital satellite services. Topics discussed include performance evaluation issues for integrated protocols, packet network operations, the computer network theory and multiple-access, microwave single sideband systems, switching architectures, fiber optic systems, wireless local communications, modulation, coding, and synchronization, remote switching, software quality, transmission, and expert systems in network operations. Consideration is given to wide area networks, image and speech processing, office communications application protocols, multimedia systems, customer-controlled network operations, digital radio systems, channel modeling and signal processing in digital communications, earth station/on-board modems, computer communications system performance evaluation, source encoding, compression, and quantization, and adaptive communications systems.

Secure Remote Access Issues in a Control Center Environment

NASA Technical Reports Server (NTRS)

Pitts, Lee; McNair, Ann R. (Technical Monitor)

2002-01-01

The ISS finally reached an operational state and exists for local and remote users. Onboard payload systems are managed by the Huntsville Operations Support Center (HOSC). Users access HOSC systems by internet protocols in support of daily operations, preflight simulation, and test. In support of this diverse user community, a modem security architecture has been implemented. The architecture has evolved over time from an isolated but open system to a system which supports local and remote access to the ISS over broad geographic regions. This has been accomplished through the use of an evolved security strategy, PKI, and custom design. Through this paper, descriptions of the migration process and the lessons learned are presented. This will include product decision criteria, rationale, and the use of commodity products in the end architecture. This paper will also stress the need for interoperability of various products and the effects of seemingly insignificant details.

Secure Payload Access to the International Space Station

NASA Technical Reports Server (NTRS)

Pitts, R. Lee; Reid, Chris

2002-01-01

The ISS finally reached an operational state and exists for local and remote users. Onboard payload systems are managed by the Huntsville Operations Support Center (HOSC). Users access HOSC systems by internet protocols in support of daily operations, preflight simulation, and test. In support of this diverse user community, a modem security architecture has been implemented. The architecture has evolved over time from an isolated but open system to a system which supports local and remote access to the ISS over broad geographic regions. This has been accomplished through the use of an evolved security strategy, PKI, and custom design. Through this paper, descriptions of the migration process and the lessons learned are presented. This will include product decision criteria, rationale, and the use of commodity products in the end architecture. This paper will also stress the need for interoperability of various products and the effects of seemingly insignificant details.

Airborne differential absorption lidar system for water vapor investigations

NASA Technical Reports Server (NTRS)

Browell, E. V.; Carter, A. F.; Wilkerson, T. D.

1981-01-01

Range-resolved water vapor measurements using the differential-absorption lidar (DIAL) technique is described in detail. The system uses two independently tunable optically pumped lasers operating in the near infrared with laser pulses of less than 100 microseconds separation, to minimize concentration errors caused by atmospheric scattering. Water vapor concentration profiles are calculated for each measurement by a minicomputer, in real time. The work is needed in the study of atmospheric motion and thermodynamics as well as in forestry and agriculture problems.

Micro-pulse, differential absorption lidar (dial) network for measuring the spatial and temporal distribution of water vapor in the lower atmosphere

NASA Astrophysics Data System (ADS)

Spuler, Scott; Repasky, Kevin; Hayman, Matt; Nehrir, Amin

2018-04-01

The National Center for Atmospheric Research (NCAR) and Montana State Univeristy (MSU) are developing a test network of five micro-pulse differential absorption lidars to continuously measure high-vertical-resolution water vapor in the lower atmosphere. The instruments are accurate, yet low-cost; operate unattended, and eye-safe - all key features to enable the larger network needed to characterize atmospheric moisture variability which influences important processes related to weather and climate.

MODEM: A comprehensive approach to modelling outcome and costs impacts of interventions for dementia. Protocol paper.

PubMed

Comas-Herrera, Adelina; Knapp, Martin; Wittenberg, Raphael; Banerjee, Sube; Bowling, Ann; Grundy, Emily; Jagger, Carol; Farina, Nicolas; Lombard, Daniel; Lorenz, Klara; McDaid, David

2017-01-11

The MODEM project (A comprehensive approach to MODelling outcome and costs impacts of interventions for DEMentia) explores how changes in arrangements for the future treatment and care of people living with dementia, and support for family and other unpaid carers, could result in better outcomes and more efficient use of resources. MODEM starts with a systematic mapping of the literature on effective and (potentially) cost-effective interventions in dementia care. Those findings, as well as data from a cohort, will then be used to model the quality of life and cost impacts of making these evidence-based interventions more widely available in England over the period from now to 2040. Modelling will use a suite of models, combining microsimulation and macrosimulation methods, modelling the costs and outcomes of care, both for an individual over the life-course from the point of dementia diagnosis, and for individuals and England as a whole in a particular year. Project outputs will include an online Dementia Evidence Toolkit, making evidence summaries and a literature database available free to anyone, papers in academic journals and other written outputs, and a MODEM Legacy Model, which will enable local commissioners of services to apply the model to their own populations. Modelling the effects of evidence-based cost-effective interventions and making this information widely available has the potential to improve the health and quality of life both of people with dementia and their carers, while ensuring that resources are used efficiently.

Early Operations Flight Correlation of the Lunar Laser Communications Demonstration (LLCD) on the Lunar Atmosphere and Dust Environment Explorer (LADEE)

NASA Technical Reports Server (NTRS)

Peabody, Hume; Yang, Kan; Nguyen, Daniel; Cornwell, Donald

2015-01-01

The Lunar Atmosphere and Dust Environment Explorer (LADEE) mission launched on September 7, 2013 with a one month cruise before lunar insertion. The LADEE spacecraft is a power limited, octagonal, composite bus structure with solar panels on all eight sides with four vertical segments per side and 2 panels dedicated to instruments. One of these panels has the Lunar Laser Communications Demonstration (LLCD), which represents a furthering of the laser communications technology demonstration proved out by the Lunar Reconnaissance Orbiter (LRO). LLCD increases the bandwidth of communication to and from the moon with less mass and power than LROs technology demonstrator. The LLCD Modem and Controller boxes are mounted to an internal cruciform composite panel and have no dedicated radiator. The thermal design relies on power cycling of the boxes and radiation of waste heat to the inside of the panels, which then reject the heat when facing cold space. The LADEE mission includes a slow roll and numerous attitudes to accommodate the challenging thermal requirements for all the instruments on board. During the cruise phase, the internal Modem and Controller avionics for LLCD were warmer than predicted by more than modeling uncertainty would suggest. This caused concern that if the boxes were considerably warmer than expected while off, they would also be warmer when operating and could limit the operational time when in lunar orbit. The thermal group at Goddard Space Flight Center evaluated the models and design for these critical avionics for LLCD. Upon receipt of the spacecraft models and audit was performed and data was collected from the flight telemetry to perform a sanity check of the models and to correlate to flight where possible. This paper describes the efforts to correlate the model to flight data and to predict the thermal performance when in lunar orbit and presents some lessons learned.

[Consequences learned from the use of chemical weapons during the First World War for the modern military medicine].

PubMed

Belskikh, A N; Basharin, V A; Chepur, S V; Khalimov, Yu Sh; Markizova, N F

2015-08-01

The article describes the way medical service dealed with problems resulted from the use of chemical weapons during the First World War (1914-1918). It was revealed that many of the abovementioned problems remain unsolved up to the present moment. It is stated the existence of the threat of use of chemical weapons in modem military conflicts, which expands the area of responsibility for medical chemical protection. The authors proved necessity and algorithm of the training system, considered as a part of medical protection in case of adverse factors of chemical nature.

Correlation of DIAL Ozone Observations with Lightning

NASA Technical Reports Server (NTRS)

Peterson, Harold; Kuang, Shi; Koshak, William; Newchurch, Michael

2013-01-01

The purpose of this project is to see whether ozone maxima measured by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, AL may be traced back to lightning events occurring 24- 48 hours beforehand. The methodology is to start with lidar measurements of ozone from DIAL as well as ozonesonde measurements. The HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is then used to determine the origin of these ozone maxima 24-48 hours prior. Data from the National Lightning Detection Network (NLDN) are used to examine the presence/absence of lightning along the trajectory. This type of analysis suggests that lightning-produced NOx may be responsible for some of the ozone maxima over Huntsville.

Characterization of a 16-Bit Digitizer for Lidar Data Acquisition

NASA Technical Reports Server (NTRS)

Williamson, Cynthia K.; DeYoung, Russell J.

2000-01-01

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

Design of Instrument Dials for Maximum Legibility: 1. Development of Methodology and Some Preliminary Results

DTIC Science & Technology

1947-10-20

Peyohology Lehlgh University Bothlehea, mnnsylvania Attni nr. Adalbert Ford nepmrtmnnt of Psychology University of Maryland College Park, Maryland...light sources consi-itcd of Mazda lamps In cans* The sample dial was so illuminated that the w’.iii.e markings were 5 foot lamberta on • background

Lidar and Dial application for detection and identification: a proposal to improve safety and security

NASA Astrophysics Data System (ADS)

Gaudio, P.; Malizia, A.; Gelfusa, M.; Murari, A.; Parracino, S.; Poggi, L. A.; Lungaroni, M.; Ciparisse, J. F.; Di Giovanni, D.; Cenciarelli, O.; Carestia, M.; Peluso, E.; Gabbarini, V.; Talebzadeh, S.; Bellecci, C.

2017-01-01

Nowadays the intentional diffusion in air (both in open and confined environments) of chemical contaminants is a dramatic source of risk for the public health worldwide. The needs of a high-tech networks composed by software, diagnostics, decision support systems and cyber security tools are urging all the stakeholders (military, public, research & academic entities) to create innovative solutions to face this problem and improve both safety and security. The Quantum Electronics and Plasma Physics (QEP) Research Group of the University of Rome Tor Vergata is working since the 1960s on the development of laser-based technologies for the stand-off detection of contaminants in the air. Up to now, four demonstrators have been developed (two LIDAR-based and two DIAL-based) and have been used in experimental campaigns during all 2015. These systems and technologies can be used together to create an innovative solution to the problem of public safety and security: the creation of a network composed by detection systems: A low cost LIDAR based system has been tested in an urban area to detect pollutants coming from urban traffic, in this paper the authors show the results obtained in the city of Crotone (south of Italy). This system can be used as a first alarm and can be coupled with an identification system to investigate the nature of the threat. A laboratory dial based system has been used in order to create a database of absorption spectra of chemical substances that could be release in atmosphere, these spectra can be considered as the fingerprints of the substances that have to be identified. In order to create the database absorption measurements in cell, at different conditions, are in progress and the first results are presented in this paper.

Simulation study of communication link for Pioneer Saturn/Uranus atmospheric entry probe. [signal acquisition by candidate modem for radio link

NASA Technical Reports Server (NTRS)

Hinrichs, C. A.

1974-01-01

A digital simulation is presented for a candidate modem in a modeled atmospheric scintillation environment with Doppler, Doppler rate, and signal attenuation typical of the radio link conditions for an outer planets atmospheric entry probe. The results indicate that the signal acquisition characteristics and the channel error rate are acceptable for the system requirements of the radio link. The simulation also outputs data for calculating other error statistics and a quantized symbol stream from which error correction decoding can be analyzed.

National Program for Inspection of Non-Federal Dams. Prym Manufacturing Co. Dam (CT 00169), Thames River Basin, Killingly, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1979-06-01

Service (DDS), which offers speeds of 19.2K bps and 56K bps. Instead of modems , DDS service requires a Channel Service Unit (CSU), to terminate each...Bell 103 modem that automatically calls for help if the DDS link goes down. DDS users can also use their own schemes to protect their transmissions...Switched 56 service provides 700 numbers for 56K transmission in some 60 odd cities, including areas such as Orlando, San Diego, and the Washington

Real-Time Acquisition and Processing System (RTAPS) Version 1.1 Installation and User’s Manual.

DTIC Science & Technology

1986-08-01

The language is incrementally compiled and procedure-oriented. It is run on an 8088 processor with 56K of available user RAM. The master board features...RTAPS/PC computers. The wiring configuration is shown in figure 10. Switch Modem Port MAC P5 or P6* 2, B4 3 B8 1%7 1 B10 *P6 recommended Figure 10. $MAC...activated switch. The AXAC output port is physically connected to the modem input on the switch. The subchannels are the labeled terminal connections

Accuracy and consistency of weights provided by home bathroom scales

PubMed Central

2013-01-01

Background Self-reported body weight is often used for calculation of Body Mass Index because it is easy to collect. Little is known about sources of error introduced by using bathroom scales to measure weight at home. The objective of this study was to evaluate the accuracy and consistency of digital versus dial-type bathroom scales commonly used for self-reported weight. Methods Participants brought functioning bathroom scales (n = 18 dial-type, n = 43 digital-type) to a central location. Trained researchers assessed accuracy and consistency using certified calibration weights at 10 kg, 25 kg, 50 kg, 75 kg, 100 kg, and 110 kg. Data also were collected on frequency of calibration, age and floor surface beneath the scale. Results All participants reported using their scale on hard surface flooring. Before calibration, all digital scales displayed 0, but dial scales displayed a mean absolute initial weight of 0.95 (1.9 SD) kg. Digital scales accurately weighed test loads whereas dial-type scale weights differed significantly (p < 0.05). Imprecision of dial scales was significantly greater than that of digital scales at all weights (p < 0.05). Accuracy and precision did not vary by scale age. Conclusions Digital home bathroom scales provide sufficiently accurate and consistent weights for public health research. Reminders to zero scales before each use may further improve accuracy of self-reported weight. PMID:24341761

Lidars as an operational tool for meteorology and advanced atmospheric research

NASA Astrophysics Data System (ADS)

Simeonov, Valentin; Dinoev, Todor; Serikov, Ilya; Froidevaux, Martin; Bartlome, Marcel; Calpini, Bertrand; Bobrovnikov, Sergei; Ristori, Pablo; van den Bergh, Hubert; Parlange, Marc; Archinov, Yury

2010-05-01

The talk will present the concept and observation results of three advanced lidar systems developed recently at the Swiss federal Institute of Technology- Lausanne (EPFL) Switzerland. Two of the systems are Raman lidars for simultaneous water vapor, temperature and aerosol observations and the third one is an ozone UV DIAL system. The Ranan lidars use vibrational water vapor and nitrogen signals to derive water vapor mixing ratio and temperature, aerosol extinction and backscatter are measured using pure-rotational Raman and elastic signals. The first Raman lidar (RALMO) is a fully automated, water vapor /temperature/aerosol lidar developed for operational use by the Swiss meteorological office (MeteoSiss). The lidar supplies water vapor mixing ratio and temperature plus aerosol extinction and backscatter coefficients at 355 nm. The operational range of the lidar is 100-7000 m (night time) and 100- 5000 m (daytime) with time resolution of 30 min. The spatial resolution varies with height from 25 to 300 m in order to maintain the maximum measurement error of 10%. The system is designed to provide long-term database with minimal instrument-induced variations in time of the measured parameters. The lidar has been in regular operation in the main aerological station of Meteoswiss- Payerne since September 2008. The second Raman lidar is a new generation, solar-blind system with an operational range 10-500 m and high spatial (1.5 m) and temporal (1 s) resolutions designed for simultaneous humidity, temperature, and aerosol measurements in the lower atmosphere. To maintain the measurement accuracy while operating with fixed spatial and temporal resolution, the receiver is designed to provide lower than ten dynamic range of the signals within the distance range of the lidar. The lidar has 360° azimuth and 240°elevation scanning ability. The lidar was used in two field campaigns aiming to study the structure of the lower atmosphere over complex terrains and, in particular, to advance our understanding of turbulent blending mechanisms in the unstable atmosphere. The third lidar is an ozone UV DIAL system designed for studies of the upper troposphere, lower stratosphere ozone exchange processes. The lidar is based on a commercial fourth harmonic Nd:YAG laser. The DIAL wavelengths (284 and 304 nm) are produced by stimulated Raman conversion in high pressure nitrogen. A 76 cm in diameter Cassegrein telescope is used in the receiver and the spectral separation of the signals is carried out by an imaging-grating based polychromator. The operational distance of the lidar is 6000 -12000 m ASL with a statistical error lower than 10%. The lidar is deployed at the High Altitude Research Station Jungfraujoch at 3600 m altitude in the Swiss Alps. The lidar accuracy was verified by comparison to profiles taken by ECC balloon-borne sondes launched by Meteoswiss from Payerne. The lidar has been in use from September 2008 and since that time several stratospheric intrusions and cases of intercontinental transport and transport from the atmospheric boundary layer have been observed.

Monitoring Tropospheric Ozone Enhancement in the Front Range Using the Gsfc Tropoz DIAL during Discover - AQ 2014

NASA Astrophysics Data System (ADS)

Sullivan, J. T.; McGee, T. J.; Hoff, R. M.; Twigg, L.; Sumnicht, G. K.

2014-12-01

Tropospheric ozone profiles have been retrieved from the new ground based National Aeronautics and Space Administration (NASA) Goddard Space Flight Center TROPospheric OZone DIfferential Absorption Lidar (GSFC TROPOZ DIAL) in Fort Collins, CO from 200 m to 16 km AGL. These measurements were taken as part of NASA's DISCOVER-AQ campaign in July/August 2014. Measurements were made during simultaneous aircraft spirals over the lidar site as well as collocated ozonesonde launches. Ozone enhancement from local sources typically occurred in the mid-afternoon convection period, especially when there was light winds and low cloud cover. Interesting ozone profiles and time series data will be shown. Current atmospheric satellite instruments cannot peer through the optically thick stratospheric ozone layer to remotely sense boundary layer tropospheric ozone. In order to monitor this lower ozone more effectively, the Tropospheric Ozone Lidar Network (TOLNet) has been developed, which currently consists of five stations across the US. Three of these lidars, including the GSFC TROPOZ DIAL, recorded measurements during the DISCOVER-AQ campaign. The GSFC TROPOZ DIAL is based on the Differential Absorption Lidar (DIAL) technique, which currently detects two wavelengths, 289 and 299 nm. Ozone is absorbed more strongly at 289 nm than at 299 nm. The DIAL technique exploits this difference between the returned backscatter signals to obtain the ozone number density as a function of altitude. The transmitted wavelengths are generated by focusing the output of a quadrupled Nd:YAG laser beam (266 nm) into a pair of Raman cells, filled with high pressure hydrogen and deuterium. Stimulated Raman Scattering (SRS) within the focus generates a significant fraction of the pump energy at the first Stokes shift. With the knowledge of the ozone absorption coefficient at these two wavelengths, the range resolved number density can be derived.

Inexpensive automated paging system for use at remote research sites

USGS Publications Warehouse

Sargent, S.L.; Dey, W.S.; Keefer, D.A.

1998-01-01

The use of a flow-activated automatic sampler at a remote research site required personnel to periodically visit the site to collect samples and reset the automatic sampler. To reduce site visits, a cellular telephone was modified for activation by a datalogger. The purpose of this study was to demonstrate the use and benefit of the modified telephone. Both the power switch and the speed-dial button on the telephone were bypassed and wired to a relay driver. The datalogger was programmed to compare values of a monitored environmental parameter with a target value. When the target value was reached or exceeded, the datalogger pulsed a relay driver, activating power to the telephone. A separate relay activated the speed dial, dialing the number of a tone-only pager. The use of this system has saved time and reduced travel costs by reducing the number of trips to the site, without the loss of any data.The use of a flow-activated automatic sampler at a remote research site required personnel to periodically visit the site to collect samples and reset the automatic sampler. To reduce site visits, a cellular telephone was modified for activation by a datalogger. The purpose of this study was to demonstrate the use and benefit of the modified telephone. Both the power switch and the speed-dial button on the telephone were bypassed and wired to a relay driver. The datalogger was programmed to compare values of a monitored environmental parameter with a target value. When the target value was reached or exceeded, the datalogger pulsed a relay driver, activating power to the telephone. A separate relay activated the speed dial, dialing the number of a tone-only pager. The use of this system has saved time and reduced travel costs by reducing the number of trips to the site, without the loss of any data.

General Aviation Flight Test of Advanced Operations Enabled by Synthetic Vision

NASA Technical Reports Server (NTRS)

Glaab, Louis J.; Hughhes, Monica F.; Parrish, Russell V.; Takallu, Mohammad A.

2014-01-01

A flight test was performed to compare the use of three advanced primary flight and navigation display concepts to a baseline, round-dial concept to assess the potential for advanced operations. The displays were evaluated during visual and instrument approach procedures including an advanced instrument approach resembling a visual airport traffic pattern. Nineteen pilots from three pilot groups, reflecting the diverse piloting skills of the General Aviation pilot population, served as evaluation subjects. The experiment had two thrusts: 1) an examination of the capabilities of low-time (i.e., <400 hours), non-instrument-rated pilots to perform nominal instrument approaches, and 2) an exploration of potential advanced Visual Meteorological Conditions (VMC)-like approaches in Instrument Meteorological Conditions (IMC). Within this context, advanced display concepts are considered to include integrated navigation and primary flight displays with either aircraft attitude flight directors or Highway In The Sky (HITS) guidance with and without a synthetic depiction of the external visuals (i.e., synthetic vision). Relative to the first thrust, the results indicate that using an advanced display concept, as tested herein, low-time, non-instrument-rated pilots can exhibit flight-technical performance, subjective workload and situation awareness ratings as good as or better than high-time Instrument Flight Rules (IFR)-rated pilots using Baseline Round Dials for a nominal IMC approach. For the second thrust, the results indicate advanced VMC-like approaches are feasible in IMC, for all pilot groups tested for only the Synthetic Vision System (SVS) advanced display concept.

Mixed garnet laser crystals for water vapour DIAL transmitter

NASA Astrophysics Data System (ADS)

Treichel, Rainer; Czeranowsky, Christoph; Ileri, Bilge; Petermann, Klaus; Huber, Günter

2017-11-01

There are more or less well established technologies such as the optical-parametric-oscillator (OPO), the Raman-laser, and the Ti-Sapphire laser, which are able to emit laser light in the region of the water vapour absorption lines. For WALES the regions of about 935 nm, 942 nm, and 944 nm have been identified as the most suitable wavelength ranges. However, each of these laser designs is highly sophisticated. Current baseline for WALES is the Ti-Sapphire laser. A fourth possibility to achieve these wavelength ranges is to shift the groundstate laser lines (938 nm and 946 nm) of the Nd:YAG laser by replacing Aluminium and Yttrium by other rare earth elements. Changes of the host lattice characteristics lead to a shift of the upper and lower laser levels. These modified crystals are summarized under the name of "Mixed Garnet" crystals. Only the Mixed Garnet lasers can be pumped directly with diode laser and use a direct approach to generate the required laser pulses without frequency conversion. Therefore no additional non-linear crystals are needed and a higher electric to optical efficiency is expected as well as single frequency operation using spectral tuning elements like etalons. Such lasers have the great potential to fulfil the requirements and to become the preferred transmitter concept for WALES as well as for follow up missions. Within a ESA study several crystal compositions have been grown, spectrally characterised and analysed. Absorbed space radiation energy in the crystal lattice causes colour centres, which can reabsorb the pump and laser wavelength and consequently reduce the laser gain considerably. Co-dopants such as Chromium and Cerium are able to suppress the colour centres and are candidates for effective radiation hardening. The results of the crystal tuning, the co-doping with different radiation hardeners and the radiation tests will be presented. There applicability for a space based water vapour DIAL transmitter will be discussed.

Design of Laser Based Monitoring Systems for Compliance Management of Odorous and Hazardous Air Pollutants in Selected Chemical Industrial Estates at Hyderabad, India

NASA Astrophysics Data System (ADS)

Sudhakar, P.; Kalavathi, P.; Ramakrishna Rao, D.; Satyanarayna, M.

2014-12-01

Industrialization can no longer sustain without internalization of the concerns of the receiving environment and land-use. Increased awareness and public pressure, coupled with regulatory instruments and bodies exert constant pressure on industries to control their emissions to a level acceptable to the receiving environment. However, when a group of industries come-up together as an industrial estate, the cumulative impacts of all the industries together often challenges the expected/desired quality of receiving environment, requiring stringent pollution control and monitoring measures. Laser remote sensing techniques provide powerful tools for environmental monitoring. These methods provide range resolved measurements of concentrations of various gaseous pollutants and suspended particulate matter (SPM) not only in the path of the beam but over the entire area. A three dimensional mapping of the pollutants and their dispersal can be estimated using the laser remote sensing methods on a continuous basis. Laser Radar (Lidar) systems are the measurements technology used in the laser remote sensing methods. Differential absorption lidar (DIAL) and Raman Lidar technologies have proved to be very useful for remote sensing of air pollutants. DIAL and Raman lidar systems can be applied for range resolved measurements of molecules like SO2, NO2, O3 Hg, CO, C2H4, H2O, CH4, hydrocarbons etc. in real time on a continuous basis. This paper describes the design details of the DAIL and Raman lidar techniques for measurement of various hazardous air pollutants which are being released into the atmosphere by the chemical industries operating in the Bachupally industrial Estate area at Hyderabad, India. The relative merits of the two techniques have been studied and the minimum concentration of pollutants that can be measured using these systems are presented. A dispersion model of the air pollutants in the selected chemical industrial estates at Hyderabad has been developed.

The McCarron-Dial System--An Approach to Clinical, Vocational, and Educational Evaluation.

ERIC Educational Resources Information Center

Dial, Jack G.; And Others

The McCarron-Dial System is useful for both vocational and clinical evaluation of neuropsychologically disabled adults. Five factors (verbal-cognitive, sensory, motor, emotional, and integration coping) are used to predict vocational competency, which is measured by work samples and behavior scales, during the first twelve months of a client's…

Airborne Dial Remote Sensing of the Arctic Ozone Layer

NASA Technical Reports Server (NTRS)

Wirth, Martin; Renger, Wolfgang; Ehret, Gerhard

1992-01-01

A combined ozone and aerosol LIDAR was developed at the Institute of Physics of the Atmosphere at the DLR in Oberpfaffenhofen. It is an airborne version, that, based on the DIAL-principle, permits the recording of two-dimensional ozone profiles. This presentation will focus on the ozone-part; the aerosol subsection will be treated later.

Cellular Telephone Dialing Influences Kinematic and Spatiotemporal Gait Parameters in Healthy Adults.

PubMed

Seymour, Kelly M; Higginson, Christopher I; DeGoede, Kurt M; Bifano, Morgan K; Orr, Rachel; Higginson, Jill S

2016-01-01

Gait speed is typically reduced when individuals simultaneously perform other tasks. However, the impact of dual tasking on kinetic and kinematic gait parameters is unclear because these vary with gait speed. The objective of this study was to identify whether dual tasking impacts gait in healthy adults when speed is constant. Twenty-two healthy adults dialed a cell phone during treadmill walking at a self-selected speed while kinetic, kinematic, and spatial parameters were recorded. Results indicated that dual tasking did not impact phone dialing speed, but increased stride width, peak knee flexion during stance, and peak plantarflexion, and decreased knee and ankle range of motion. Dual tasking appears to influence kinematic gait variables in a manner consistent with promotion of stability.

Rapid instrument prototyping with open source hardware and software: Application to water quality in hypersaline estuaries.

NASA Astrophysics Data System (ADS)

Loose, B.; O'Shea, R.

2016-02-01

We describe the design and deployment of a water quality sonde that utilizes mobile phone networks for near-real time data telemetry. The REOL or Realtime Estuary Ocean Logger has the unique and valuable capability of logging data internally and simultaneously relaying the information to a webserver using a cellular modem. The internal circuitry consists of a GSM cellular modem, a microcontroller, and an SD card for data storage - these components are low cost, and backed up with circuit diagrams and programming libraries that are published under open source license. This configuration is versatile and is capable of reading instrument output from a broad spectrum of devices, including serial, TTL, analog voltage (0 - 5V), and analog current (typically 4-20 mA). We find the greatest challenges lie in development of smart software that is capable of handling the conditions brought on by this harsh environment. We have programmed the sonde to first determine whether it is submerged by water, and record the temperature on the electronics before deciding whether to telemeter measurements over the cellular network. The Google App EngineTM provides an interactive visualization platform. We have tested the REOL with a variety of water quality sensors. In the configuration described here, we use a thermistor, depth gauge and torroidal conductivity sensor to measure water temperature, water level and conductivity up to 200 mS/cm. The latter is necessary for studies in hypersaline estuaries, where porewater salinity can exceed 100 g/kg. We present data from two estuaries in West Africa and from a longer-term deployment in the Narragansett Bay, Rhode Island.

Transmission of chirality through space and across length scales

NASA Astrophysics Data System (ADS)

Morrow, Sarah M.; Bissette, Andrew J.; Fletcher, Stephen P.

2017-05-01

Chirality is a fundamental property and vital to chemistry, biology, physics and materials science. The ability to use asymmetry to operate molecular-level machines or macroscopically functional devices, or to give novel properties to materials, may address key challenges at the heart of the physical sciences. However, how chirality at one length scale can be translated to asymmetry at a different scale is largely not well understood. In this Review, we discuss systems where chiral information is translated across length scales and through space. A variety of synthetic systems involve the transmission of chiral information between the molecular-, meso- and macroscales. We show how fundamental stereochemical principles may be used to design and understand nanoscale chiral phenomena and highlight important recent advances relevant to nanotechnology. The survey reveals that while the study of stereochemistry on the nanoscale is a rich and dynamic area, our understanding of how to control and harness it and dial-up specific properties is still in its infancy. The long-term goal of controlling nanoscale chirality promises to be an exciting journey, revealing insight into biological mechanisms and providing new technologies based on dynamic physical properties.

Fieldable Fourier transform spectrometer

NASA Astrophysics Data System (ADS)

Hatchell, Brian K.; Harper, Warren W.; Schultz, John F.

2004-10-01

The infrared sensors group at the Pacific Northwest National Laboratory (PNNL) is focused on the science and technology of remote and in-situ chemical sensors for detecting proliferation and countering terrorism. To support these vital missions, PNNL is developing frequency-modulation techniques for remote probing over long optical paths by means of differential-absorption light detecting and ranging (LIDAR). This technique can easily monitor large areas, or volumes, that could only be accomplished with a large network of point sensors. Recently, PNNL began development of a rugged frequency-modulation differential-abosrption LIDAR (FM-DIAL) system to conduct field experiments. To provide environmentla protection for the system and facilitate field deployments and operations, a large, well insulated, temperature controlled trailer was specified and acquired. The trailer was outfitted with a shock-mounted optical bench, an electronics rack, a liquid nitrogen Dewar, and a power generator. A computer-controlled gimbal-mounted mirror was added to allow the telescope beam to be accurately pointed in both the vertical and horizontal plane. This turned out to be the most complicated addition, and is described in detail. This paper provides an overview of the FM-DIAL system and illustrates innovative solutions developed to overcome several alignment and stability issues encountered in the field.

Development of an Intelligent Monitoring System for Geological Carbon Sequestration (GCS) Systems

NASA Astrophysics Data System (ADS)

Sun, A. Y.; Jeong, H.; Xu, W.; Hovorka, S. D.; Zhu, T.; Templeton, T.; Arctur, D. K.

2016-12-01

To provide stakeholders timely evidence that GCS repositories are operating safely and efficiently requires integrated monitoring to assess the performance of the storage reservoir as the CO2 plume moves within it. As a result, GCS projects can be data intensive, as a result of proliferation of digital instrumentation and smart-sensing technologies. GCS projects are also resource intensive, often requiring multidisciplinary teams performing different monitoring, verification, and accounting (MVA) tasks throughout the lifecycle of a project to ensure secure containment of injected CO2. How to correlate anomaly detected by a certain sensor to events observed by other devices to verify leakage incidents? How to optimally allocate resources for task-oriented monitoring if reservoir integrity is in question? These are issues that warrant further investigation before real integration can take place. In this work, we are building a web-based, data integration, assimilation, and learning framework for geologic carbon sequestration projects (DIAL-GCS). DIAL-GCS will be an intelligent monitoring system (IMS) for automating GCS closed-loop management by leveraging recent developments in high-throughput database, complex event processing, data assimilation, and machine learning technologies. Results will be demonstrated using realistic data and model derived from a GCS site.

Evaluation of CDMA system capacity for mobile satellite system applications

NASA Technical Reports Server (NTRS)

Smith, Partrick O.; Geraniotis, Evaggelos A.

1988-01-01

A specific Direct-Sequence/Pseudo-Noise (DS/PN) Code-Division Multiple-Access (CDMA) mobile satellite system (MSAT) architecture is discussed. The performance of this system is evaluated in terms of the maximum number of active MSAT subscribers that can be supported at a given uncoded bit-error probability. The evaluation decouples the analysis of the multiple-access capability (i.e., the number of instantaneous user signals) from the analysis of the multiple-access mutliplier effect allowed by the use of CDMA with burst-modem operation. We combine the results of these two analyses and present numerical results for scenarios of interest to the mobile satellite system community.

Two Nights on a Flying Observatory: A KAO Journal

NASA Technical Reports Server (NTRS)

Stryker, Pam; Willis, Marsha

1994-01-01

We are the first participants in the "Science in the Stratosphere" program, sponsored by NASA and the University of Texas at Austin. The purpose of the program is to bring the techniques and excitement of modem astronomy into the classroom. Our job is to become familiar with the normal KAO operations, and learn from the staff and scientists during an actual observing flight. We are going to fly on missions to observe galactic and extragalactic star-forming regions in the far infrared region of the spectrum. All of our expectations spring from this simple working description. Little do we know, however, what really lies ahead for us!

A new modem for microwave time synchronisation via geosynchronous telecommunication satellites

NASA Astrophysics Data System (ADS)

Dienert, Michael

1992-06-01

A study illustrating the two way time transfer technique and describing the use of this technique with the MITREX (Microwave Time and Range Experiment) SATRE (Satellite Time and Range Experiment) modems is presented. The two way time transfer technique via geosynchronous telecom satellites is one of the most accurate methods for synchronization and comparison of remote clocks. Most of the unknown propagation delays can be eliminated by the two way principle. The use of a coherent spread spectrum technique with a truncated pseudonoise code offers a resolution better than 30 ps of the measured time interval. The receiver is built around a Delay Locked Loop (DLL), which correlates the received signal with the known PN sequence to derive the control signal of the loop. In the locked state both PN sequences are synchronous and tracking errors of less than 30 ps are possible. Results showing the accuracy of the modem depending on signal to noise ratio and variation of total input power levels are presented and show that the expected improvement of the jitter of the internal delay by an increase of the chip rate is possible.

A Robotic Communications Gateway for Ocean Observations

NASA Astrophysics Data System (ADS)

Orcutt, J. A.; Berger, J.; Laske, G.; Babcock, J.

2015-12-01

We describe a new technology that can provide real-time telemetry of sensor data from the ocean bottom. The breakthrough technology that makes this system possible is an autonomous surface vehicle called the Wave Glider developed by Liquid Robotics, Inc. of Sunnyvale, CA., which harvests wave and solar energy for motive and electrical power. The free-floating surface communications gateway uses a Liquid Robotics wave glider comprising a surfboard-sized float towed by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave glider is equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land are provided by the Iridium satellite constellation. Wave gliders have demonstrated trans-oceanic range and long-term station keeping capabilities. The topside acoustics communications package is mounted in a shallow tow body, which uses a WHOI micro modem and a Benthos low frequency, directional transducer. A matching bottom side modem and transducer are mounted on the ocean bottom package. Tests of the surface gateway in 4000 m of water demonstrated an acoustic efficiency of approximately 256 bits/J. For example, it has the ability to send four channels of compressed, one sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.36 W and a latency of about three minutes. This gateway is used to send near-real-time data from a broadband ocean bottom seismic observatory; we are presently designing and constructing a seafloor package with a two-year operational life. We have found that for frequencies f where f<10mHz, 35mHz < f < 120mHz and f>~3Hz, the vertical component, seafloor system noise characteristics are generally superior to similar observatories on land. Increasing the density of these stations over the majority of the surface of Earth; that is, the oceans will greatly enhance the resolution of deep Earth structure and serve civil needs including tsunami warning. The robotic technology is readily applicable for other ocean observations.

ADDOSS: Autonomously Deployed Deep-ocean Seismic System - Communications Gateway for Ocean Observatories

NASA Astrophysics Data System (ADS)

Laske, Gabi; Berger, Jon; Orcutt, John; Babcock, Jeff

2014-05-01

We describe an autonomously deployable, communications gateway designed to provide long-term and near real-time data from ocean observatories. The key features of this new system are its abilities to telemeter sensor data from the seafloor to shore without cables or moorings, and to be deployed without a ship, thereby greatly reducing life-cycle costs. The free-floating surface communications gateway utilizes a Liquid Robotics wave glider comprising a surfboard-sized float towed by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave glider is equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land are provided by the Iridium satellite constellation. Wave gliders have demonstrated trans-oceanic range and long-term station keeping capabilities. The acoustics communications package is mounted in a shallow tow body which utilizes a WHOI micro modem and a Benthos low frequency, directional transducer. A matching modem and transducer is mounted on the ocean bottom package. Tests of the surface gateway in 4350 m of water demonstrated an acoustic efficiency of approximately 396 bits/J. For example, it has the ability to send 4 channels of compressed, 1 sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.15 W and a latency of less than 3 minutes. This gateway is used to send near real-time data from a broadband ocean bottom seismic observatory, first during short week-to-months long test deployments but will ultimately be designed for a two-year operational life. Such data from presently unobserved oceanic areas are critical for both national and international agencies in monitoring and characterizing earthquakes, tsunamis, and nuclear explosions. We present initial results from a two short-term OBS test deployments off-shore La Jolla, at water depths of 1000 m and of nearly 4000 m.

The changing nature of spacecraft operations: From the Vikings of the 1970's to the great observatories of the 1990's and beyond

NASA Technical Reports Server (NTRS)

Ledbetter, Kenneth W.

1992-01-01

Four trends in spacecraft flight operations are discussed which will reduce overall program costs. These trends are the use of high-speed, highly reliable data communications systems for distributing operations functions to more convenient and cost-effective sites; the improved capability for remote operation of sensors; a continued rapid increase in memory and processing speed of flight qualified computer chips; and increasingly capable ground-based hardware and software systems, notably those augmented by artificial intelligence functions. Changes reflected by these trends are reviewed starting from the NASA Viking missions of the early 70s, when mission control was conducted at one location using expensive and cumbersome mainframe computers and communications equipment. In the 1980s, powerful desktop computers and modems enabled the Magellan project team to operate the spacecraft remotely. In the 1990s, the Hubble Space Telescope project uses multiple color screens and automated sequencing software on small computers. Given a projection of current capabilities, future control centers will be even more cost-effective.

Western blot analysis of sera from dogs with suspected food allergy.

PubMed

Favrot, Claude; Linek, Monika; Fontaine, Jacques; Beco, Luc; Rostaher, Ana; Fischer, Nina; Couturier, Nicolas; Jacquenet, Sandrine; Bihain, Bernard E

2017-04-01

Food allergy is often suspected in dogs with clinical signs of atopic dermatitis. This diagnosis is confirmed with an elimination diet and a subsequent challenge with regular food. Laboratory tests for the diagnosis of food allergy in dogs are unreliable and/or technically difficult. Cyno-DIAL ® is a Western blot method that might assist with the selection of an appropriate elimination diet. To evaluate the performance of Cyno-DIAL ® for the selection of an elimination diet and diagnosis of food allergy. Thirty eight dogs with atopic dermatitis completed an elimination diet. Combining the results of the diet trials and the challenges, 14 dogs were classified as food allergic (FA), 22 as nonfood-allergic and two as ambiguous cases. Amongst all dogs and amongst dogs with a clinical diagnosis of FA, 3% and 7% (respectively) were positive to Royal Canin Anallergenic ® , Vet-Concept Kanguru ® or Vet-Concept Dog Sana ® ; 8% and 7% to Hill's d/d Duck and Rice ® ; 8% and 21% to Hill's z/d Ultra Allergen Free ® ; 53% and 64% to Eukanuba Dermatosis FP ® ; and 32% and 43% to a home-cooked diet of horse meat, potatoes and zucchini. The specificity and sensitivity of Cyno-DIAL ® for diagnosing food allergy were 73% and 71%, respectively. Although Cyno-DIAL ® was considered potentially useful for identifying appropriate foods for elimination diet trials, it cannot be recommended for the diagnosis of food allergy. The Cyno-DIAL ® test performed better than some previously evaluated ELISA-based tests. © 2017 ESVD and ACVD.

Optical Access Networks

NASA Astrophysics Data System (ADS)

Zheng, Jun; Ansari, Nirwan

2005-01-01

Call for Papers: Optical Access Networks

Guest Editors Jun Zheng, University of Ottawa Nirwan Ansari, New Jersey Institute of Technology

Submission Deadline: 1 June 2005

Background

Scope of Contributions

• Optical access network architectures and protocols
• Passive optical networks (BPON, EPON, GPON, etc.)
• Active optical networks
• Multiple access control
• Multiservices and QoS provisioning
• Network survivability
• Field trials and standards
• Performance modeling and analysis

Manuscript Submission

"Dial-R,""Motor-Free Visual Perception Test", and "Peabody Picture Vocabulary Test": Interpretation from a Kindergarten Screening.

ERIC Educational Resources Information Center

Carmichael, Karla Delle

The Developmental Indicators for the Assessment of Learning-Revised (Dial-R) Test, the Peabody Picture Vocabulary Test (PPVT), and the Motor-Free Visual Perception Test (MFVPT) were used for kindergarten screening in three rural schools in Texas. Teachers in the schools requested a handbook that would help them interpret test scores and plan…

Dialing in single-site reactivity of a supported calixarene-protected tetrairidium cluster catalyst

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

Palermo, Andrew; Solovyov, Andrew; Ertler, Daniel

2017-05-04

A closed Ir 4carbonyl cluster,1, comprising a tetrahedral metal frame and threetert-butyl-calix[4]arene(OPr) 3(OCH 2PPh 2) (Ph = phenyl; Pr = propyl) ligands at the basal plane, was silica supported and consists of “*” and “S” sites, which could be dialed in selectively for controlling ethylene hydrogenation catalysis.

The accuracy of mean-growth estimates made with dial-gage dendrometers

Treesearch

Barton M. Blum; Dale S. Solomon

1966-01-01

In recent years a great deal of interest has been focused on tree growth as measured with relatively precise instruments over short periods of time. These growth measurements are usually made with vernier-band dendrometers similar to those described by Hall (1944) and Liming (1957), or dial-gage dendrometers similar to those described by Reineke (1932) and Daubenmire (...

Novel self-powered pH indicator using ionic polymeric gel muscles

NASA Astrophysics Data System (ADS)

Shahinpoor, Mohsen

1994-05-01

A novel design for a torsional spring-loaded pH indicator using ionic polymeric gel fibrous muscles is presented. The essential parts of the proposed self-powered pH indicator are a pair of co-axial and concentric cylinders, an assembly of fibrous polyacrylonitrile (PAN) muscles, a torsional spring, and a dial indicator. The two co-axial cylinders are such that the inner cylinder may pivotally rotate about the central rotation axis that is fixed to the inner bottom or side of the outer cylinder. The outer cylinder also serves as a reservoir for any liquid whose pH is to be determined either statically or dynamically. The internal cylindrical drum is further equipped with a dial indicator on one of its outer end caps such that when a pH environment is present the contraction or expansion of the PAN fibers cause the inner drum to rotate and thus give a reading of the dial indicator. The motion of the dial indicator may also be converted to an electrical signal (voltage) for digital electronics display and computer control. A mathematical model is also presented for the dynamic response of the self-powered pH indicator made with contractile PAN fiber bundle assemblies.

Airborne UV DIAL Measurements of Ozone and Aerosols

NASA Technical Reports Server (NTRS)

Grant, William B.; Browell, Edward V.

2000-01-01

The NASA Langley Research Center's airborne UV Differential Absorption Lidar (DIAL) system measures vertical profiles of ozone and aerosols above and below the aircraft along its flight track. This system has been used in over 20 airborne field missions designed to study the troposphere and stratosphere since 1980. Four of these missions involved tropospheric measurement programs in the Pacific Ocean with two in the western North Pacific and two in the South Pacific. The UV DIAL system has been used in these missions to study such things as pollution outflow, long-range transport, and stratospheric intrusions; categorize the air masses encountered; and to guide the aircraft to altitudes where interesting features can be studied using the in situ instruments. This paper will highlight the findings with the UV DIAL system in the Pacific Ocean field programs and introduce the mission planned for the western North Pacific for February-April 2001. This will be an excellent opportunity for collaboration between the NASA airborne mission and those with ground-based War systems in Asia Pacific Rim countries to make a more complete determination of the transport of air from Asia to the western Pacific.

Bringing the medical library to the office desktop.

PubMed

Brown, S R; Decker, G; Pletzke, C J

1991-01-01

This demonstration illustrates LRC Remote Computer Services- a dual operating system, multi-protocol system for delivering medical library services to the medical professional's desktop. A working model draws resources from CD-ROM and magnetic media file services, Novell and AppleTalk network protocol suites and gating, LAN and asynchronous (dial-in) access strategies, commercial applications for MS-DOS and Macintosh workstations and custom user interfaces. The demonstration includes a discussion of issues relevant to the delivery of said services, particularly with respect to maintenance, security, training/support, staffing, software licensing and costs.

Complementarity of UV and IR differential absorption lidar for global measurements of atmospheric species

NASA Technical Reports Server (NTRS)

Megie, G.; Menzies, R. T.

1980-01-01

An analysis of the potential capabilities of a spectrally diversified DIAL technique for monitoring atmospheric species is presented assuming operation from an earth-orbiting platform. Emphasis is given to the measurement accuracies and spatial and temporal resolutions required to meet present atmospheric science objectives. The discussion points out advantages of spectral diversity to perform comprehensive studies of the atmosphere; in general it is shown that IR systems have an advantage in lower atmospheric measurements, while UV systems are superior for middle and upper atmospheric measurements.

Optimization of the GSFC TROPOZ DIAL retrieval using synthetic lidar returns and ozonesondes - Part 1: Algorithm validation

NASA Astrophysics Data System (ADS)

Sullivan, J. T.; McGee, T. J.; Leblanc, T.; Sumnicht, G. K.; Twigg, L. W.

2015-04-01

The main purpose of the NASA Goddard Space Flight Center TROPospheric OZone DIfferential Absorption Lidar (GSFC TROPOZ DIAL) is to measure the vertical distribution of tropospheric ozone for science investigations. Because of the important health and climate impacts of tropospheric ozone, it is imperative to quantify background photochemical and aloft ozone concentrations, especially during air quality episodes. To better characterize tropospheric ozone, the Tropospheric Ozone Lidar Network (TOLNet) has recently been developed, which currently consists of five different ozone DIAL instruments, including the TROPOZ. This paper addresses the necessary procedures to validate the TROPOZ retrieval algorithm and develops a primary standard for retrieval consistency and optimization within TOLNet. This paper is focused on ensuring the TROPOZ and future TOLNet algorithms are properly quantifying ozone concentrations and the following paper will focus on defining a systematic uncertainty analysis standard for all TOLNet instruments. Although this paper is used to optimize the TROPOZ retrieval, the methodology presented may be extended and applied to most other DIAL instruments, even if the atmospheric product of interest is not tropospheric ozone (e.g. temperature or water vapor). The analysis begins by computing synthetic lidar returns from actual TROPOZ lidar return signals in combination with a known ozone profile. From these synthetic signals, it is possible to explicitly determine retrieval algorithm biases from the known profile, thereby identifying any areas that may need refinement for a new operational version of the TROPOZ retrieval algorithm. A new vertical resolution scheme is presented, which was upgraded from a constant vertical resolution to a variable vertical resolution, in order to yield a statistical uncertainty of <10%. The optimized vertical resolution scheme retains the ability to resolve fluctuations in the known ozone profile and now allows near field signals to be more appropriately smoothed. With these revisions, the optimized TROPOZ retrieval algorithm (TROPOZopt) has been effective in retrieving nearly 200 m lower to the surface. Also, as compared to the previous version of the retrieval, the TROPOZopt has reduced the mean profile bias by 3.5% and large reductions in bias (near 15 %) were apparent above 4.5 km. Finally, to ensure the TROPOZopt retrieval algorithm is robust enough to handle actual lidar return signals, a comparison is shown between four nearby ozonesonde measurements. The ozonesondes agree well with the retrieval and are mostly within the TROPOZopt retrieval uncertainty bars (which implies that this exercise was quite successful). A final mean percent difference plot is shown between the TROPOZopt and ozonesondes, which indicates that the new operational retrieval is mostly within 10% of the ozonesonde measurement and no systematic biases are present. The authors believe that this analysis has significantly added to the confidence in the TROPOZ instrument and provides a standard for current and future TOLNet algorithms.

Airborne Lidar measurements of aerosols, mixed layer heights, and ozone during the 1980 PEPE/NEROS summer field experiment

NASA Technical Reports Server (NTRS)

Browell, E. V.; Shipley, S. T.; Butler, C. F.; Ismail, S.

1985-01-01

A detailed summary of the NASA Ultraviolet Differential Absorption Lidar (UV DIAL) data archive obtained during the EPA Persistent Elevated Pollution Episode/Northeast Regional Oxidant Study (PEPE/NEROS) Summer Field Experiment Program (July through August 1980) is presented. The UV dial data set consists of remote measurements of mixed layer heights, aerosol backscatter cross sections, and sequential ozone profiles taken during 14 long-range flights onboard the NASA Wallops Flight Center Electra aircraft. These data are presented in graphic and tabular form, and they have been submitted to the PEPE/NEROS data archive on digital magnetic tape. The derivation of mixing heights and ozone profiles from UV Dial signals is discussed, and detailed intercomparisons with measurements obtained by in situ sensors are presented.

A Proposal for Modeling Real Hardware, Weather and Marine Conditions for Underwater Sensor Networks

PubMed Central

Climent, Salvador; Capella, Juan Vicente; Blanc, Sara; Perles, Angel; Serrano, Juan José

2013-01-01

Network simulators are useful for researching protocol performance, appraising new hardware capabilities and evaluating real application scenarios. However, these tasks can only be achieved when using accurate models and real parameters that enable the extraction of trustworthy results and conclusions. This paper presents an underwater wireless sensor network ecosystem for the ns-3 simulator. This ecosystem is composed of a new energy-harvesting model and a low-cost, low-power underwater wake-up modem model that, alongside existing models, enables the performance of accurate simulations by providing real weather and marine conditions from the location where the real application is to be deployed. PMID:23748171

Advanced information society(5)

NASA Astrophysics Data System (ADS)

Tanizawa, Ippei

Based on the advancement of information network technology information communication forms informationalized society giving significant impact on business activities and life style in it. The information network has been backed up technologically by development of computer technology and has got great contribution by enhanced computer technology and communication equipments. Information is transferred by digital and analog methods. Technical development which has brought out multifunctioned modems of communication equipments in analog mode, and construction of advanced information communication network which has come out by joint work of computer and communication under digital technique, are described. The trend in institutional matter and standardization of electrical communication is also described showing some examples of value-added network (VAN).

Measurements of CO2 Column Abundance in the Low Atmosphere Using Ground Based 1.6 μm CO2 DIAL

NASA Astrophysics Data System (ADS)

Abo, M.; Shibata, Y.; Nagasawa, C.

2017-12-01

Changes in atmospheric carbon dioxide (CO2) concentration are believed to produce the largest radiative forcing for the current climate system. Accurate predictions of atmospheric CO2 concentration rely on the knowledge of its sinks and sources, transports, and its variability with time. Although this knowledge is currently unsatisfactory, numerical models use it as a way in simulating CO2 fluxes. Validating and improving the global atmospheric transport model, therefore, requires precise measurement of the CO2 concentration profile. There are two further variations on Lidar: the differential absorption Lidar (DIAL) and the integrated path differential absorption (IPDA) Lidar. DIAL/IPDA are basically for profile/total column measurement, respectively. IPDA is a special case of DIAL and can measure the total column-averaged mixing ratio of trace gases using return signals from the Earth's surface or from thick clouds based on an airborne or a satellite. We have developed a ground based 1.6 μm DIAL to measure vertical CO2 mixing ratio profiles from 0.4 to 2.5 km altitude. The goals of the CO2 DIAL are to produce atmospheric CO2 mixing ratio measurements with much smaller seasonal and diurnal biases from the ground surface. But, in the ground based lidar, return signals from around ground surface are usually suppressed in order to handle the large dynamic range. To receive the return signals as near as possible from ground surface, namely, the field of view (FOV) of the telescope must be wide enough to reduce the blind range of the lidar. While the return signals from the far distance are very weak, to enhance the sensitivity and heighten the detecting distance, the FOV must be narrow enough to suppress the sky background light, especially during the daytime measurements. To solve this problem, we propose a total column measurement method from the ground surface to 0.4 km altitude. Instead of strong signals from thick clouds such as the IPDA, the proposed method uses atmospheric return signals from 0.4 km altitude. Although laser outputs of two wavelengths, which are the system parameter of DIAL, are canceled, the proposed method needs to constantly monitor laser outputs. When the laser output ratio with two wavelengths is 1.0 ± 0.01, the error simulation result of the CO2 mixing ratio is 420.0 ± 3.9 ppm.

TT and C - First TDRSS, Then Commercial GEO and Big LEO and Now through LEO

NASA Technical Reports Server (NTRS)

Morgan, Dwayne; Bull, Barton; Grant, Charles; Streich, Ronald; Powers, Edward I. (Technical Monitor)

2001-01-01

The advent of low earth orbit (LEO) commercial communications satellites provides an opportunity to dramatically reduce Telemetry Tracking and Control (TT&C) costs of launch vehicles and Unpiloted Aerial Vehicles (UAVs) by reducing or eliminating ground infrastructure. Personnel from the Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF) in Virginia have successfully used commercial GEO & Big LEO communications satellites for Long Duration Balloon flight TT&C. In addition, TDRSS capability for these balloons has been developed by WFF for the Ultra Long Duration Balloons with the first test flight launch in January 2001 for one global circumnavigation at 120,000 feet altitude launched from Alice Springs. Australia. Numerous other low cost applications can new utilize the commercial LEO satellites for TT&C. The Flight Modern became a GSFC/WFF Advanced Range Technology Initiative (ARTI) in an effort to streamline TT&C capability to the user community at low cost. Phase I ground tests of The Flight Modem verified downlink communications quality of service and measured transmission latencies. These tests were completed last year, Phase II consisting of aircraft flight tests provide much of the data presented in this paper. Phase III of the Flight Modern baseline test program is a demonstration of the ruggedized version of the WFF Flight Modem flown on one sounding rocket launched from Sweden. Flights of opportunity have been and are being actively pursued with other centers, ranges and users at universities. The WFF goal is to reduce TT&C costs by providing a low cost COTS Flight Modem with a User Handbook containing system capability and limitation descriptions. Additionally, since data transmission is by packetized Internet Protocol (IP), data can be received and commands initialed from practically any location with no infrastructure. The WFF, like most ranges, has been using GPS receivers on sounding rockets and long duration balloons for several years, The WFF Flight Modem contains a GPS receiver to provide vehicle position for tracking and vehicle recovery. The system architecture which integrates antennas, GPS receiver, commercial satellite packet data modem. and a single board computer with custom software is described and a number of technical challenges are discussed along with the plan for their resolution. These include antenna development, high Doppler rates, reliability, environmental ruggedness, hand over between satellites and data security. An aggressive test plan is included which in addition to environmental Testing measures bit error rate latency and antenna patterns. Additional flight tests are planned far the near future on aircraft, long duration balloons and sounding rockets and these results as well as the current status of the project arc reported. Use of the WFF Flight Modem on small satellites is also being pursued. The LEO satellite constellation altitude above 1400 km is not an obstacle because most spacecraft do not require continuous Communications. The challenge is scheduling where store and forward techniques for command are required and downlink when the communications link allows connection (above 60 percent of the time depending on the satellite altitude). Sophisticated scheduling techniques utilizing 2-line orbital element sets available on the NASA/NORAD Internet site could be implemented for rare special cases. The current 9600 baud rate of the LEO communications link may be increased With special techniques that are planned for development in the WFF Flight Modem project.

Design and implementation of telephone dialer based on Arduino

NASA Astrophysics Data System (ADS)

Ma, Zilong; Lei, Ying

2017-03-01

Introduces a system design scheme of the telephone dialer based on Arduino, including the design principle, hardware and software design and the experimental results in this paper. The scheme is based on the dual tone multi frequency (DTMF) dialing mode, using the Arduino UNO as the main controller, the serial port send out the telephone number to be dialed, speaker synthesize the voice.