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Sample records for access cdma systems

  1. Use of CDMA access technology in mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Ramasastry, Jay; Wiedeman, Bob

    1995-01-01

    Use of Code Division Multiple Access (CDMA) technology in terrestrial wireless systems is fairly well understood. Similarly, design and operation of Power Control in a CDMA-based system in a terrestrial environment is also well established. Terrestrial multipath characteristics, and optimum design of the CDMA receiver to deal with multipath and fading conditions are reliably established. But the satellite environment is different. When the CDMA technology is adopted to the satellite environment, other design features need to be incorporated (for example; interleaving, open-loop and closed-loop power control design, diversity characteristics) to achieve comparable level of system performance. In fact, the GLOBALSTAR LEO/MSS system has incorporated all these features. Contrary to some published reports, CDMA retains the advantages in the satellite environment that are similar to those achieved in the terrestrial environment. This document gives a description of the CDMA waveform and other design features adopted for mobile satellite applications.

  2. A satellite mobile communication system based on Band-Limited Quasi-Synchronous Code Division Multiple Access (BLQS-CDMA)

    NASA Technical Reports Server (NTRS)

    Degaudenzi, R.; Elia, C.; Viola, R.

    1990-01-01

    Discussed here is a new approach to code division multiple access applied to a mobile system for voice (and data) services based on Band Limited Quasi Synchronous Code Division Multiple Access (BLQS-CDMA). The system requires users to be chip synchronized to reduce the contribution of self-interference and to make use of voice activation in order to increase the satellite power efficiency. In order to achieve spectral efficiency, Nyquist chip pulse shaping is used with no detection performance impairment. The synchronization problems are solved in the forward link by distributing a master code, whereas carrier forced activation and closed loop control techniques have been adopted in the return link. System performance sensitivity to nonlinear amplification and timing/frequency synchronization errors are analyzed.

  3. Measurements of Eavesdropping in a Wavelength/Time Optical CDMA (O-CDMA) System, with Data Confidentiality Implications

    SciTech Connect

    Mendez, A J; Hernandez, V J; Bennett, C V; Gagliardi, R M; Lennon, W J

    2005-07-29

    We report measurements on what an eavesdropper ''sees'' when tapping into a wavelength/time O-CDMA system in which 16 of 32 codes are ''lit''. Severe multi-access interference (MAI) provides some data confidentiality.

  4. Overloaded Minimum Total Squared Correlation Signatures Based Pilot Aided System for MC-CDMA and STBC MC-CDMA

    NASA Astrophysics Data System (ADS)

    Arifianto, M. S.; Chekima, A.; Hamid, M. Y.; Barukang, L.; Viswacheda, D. V.

    This paper proposes multiple-access schemes based on Overloaded Minimum Total Squared Correlation (TSC) signatures, namely Pilot Aided Multi-Carrier Code-Division Multiple-Access (MC-CDMA) and Pilot Aided Space Time Block Codes (STBC) MC-CDMA. Since overloaded minimum TSC signatures were used as the spreading codes, a number of sub-channels in the MC-CDMA and STBC MC-CDMA schemes were not utilized for data transmission. These empty sub-channels can be exploited for comb-type pilot signaling. To maintain low system complexity, for the pilot sub-channels Least Square (LS) estimation was employed and for interpolating the characteristics of the data sub-channels linear interpolator was applied. The validity of the schemes is confirmed by comparing them with the original MC-CDMA method using Walsh-Hadamard orthogonal codes and also with Walsh-Hadamard based STBC MC-CDMA with block-type pilot. All systems use Equal Gain Combining (EGC) or Maximum Ratio Combining (MRC) in the MC-CDMA block at the receiver. The simulation result shows that although the spreading codes of interest are not fully orthogonal codes, for a low number of users the systems under investigation performed better than their Walsh-Hadamard based counterpart. This will be valuable for Wireless Personal Area Network (PAN) where the number of users is typically low.

  5. Overview of cellular CDMA

    NASA Astrophysics Data System (ADS)

    Lee, William C. Y.

    1991-05-01

    A general description of code division multiple access (CDMA) is presented. This overview of CDMA highlights the potential of increasing capacity in future cellular communications. The author describes the mobile radio environment and its impact on narrowband and wideband propagation. The advantage of having CDMA in cellular systems is discussed, and the concept of radio capacity in cellular is introduced. The power control schemes in CDMA are analyzed in detail.

  6. System level comparison of FDMA vs. CDMA (under conference guideline constraint)

    NASA Technical Reports Server (NTRS)

    Renshaw, Ken

    1989-01-01

    The margin that is required to mitigate the near-far problem in a Code Division Multiple Access (CDMA) mobile satellite system is determined by the radio-propagation model selected, the distribution of the users in clear and shadowed environments, and implementation techniques. The use of revenue potential as a means of evaluating the relative merits of CDMA and Frequency Division Multiple Access (FDMA) systems is a convenient way to rationalize the performance of systems using high-gain and low-gain antennas. The revenue potential of CDMA is much greater than the revenue potential for FDMA for a particular satellite design considered.

  7. Adaptive beamforming in a CDMA mobile satellite communications system

    NASA Technical Reports Server (NTRS)

    Munoz-Garcia, Samuel G.

    1993-01-01

    Code-Division Multiple-Access (CDMA) stands out as a strong contender for the choice of multiple access scheme in these future mobile communication systems. This is due to a variety of reasons such as the excellent performance in multipath environments, high scope for frequency reuse and graceful degradation near saturation. However, the capacity of CDMA is limited by the self-interference between the transmissions of the different users in the network. Moreover, the disparity between the received power levels gives rise to the near-far problem, this is, weak signals are severely degraded by the transmissions from other users. In this paper, the use of time-reference adaptive digital beamforming on board the satellite is proposed as a means to overcome the problems associated with CDMA. This technique enables a high number of independently steered beams to be generated from a single phased array antenna, which automatically track the desired user signal and null the unwanted interference sources. Since CDMA is interference limited, the interference protection provided by the antenna converts directly and linearly into an increase in capacity. Furthermore, the proposed concept allows the near-far effect to be mitigated without requiring a tight coordination of the users in terms of power control. A payload architecture will be presented that illustrates the practical implementation of this concept. This digital payload architecture shows that with the advent of high performance CMOS digital processing, the on-board implementation of complex DSP techniques -in particular digital beamforming- has become possible, being most attractive for Mobile Satellite Communications.

  8. Secure Communications in High Speed Fiber Optical Networks Using Code Division Multiple Access (CDMA) Transmission

    SciTech Connect

    Han, I; Bond, S; Welty, R; Du, Y; Yoo, S; Reinhardt, C; Behymer, E; Sperry, V; Kobayashi, N

    2004-02-12

    This project is focused on the development of advanced components and system technologies for secure data transmission on high-speed fiber optic data systems. This work capitalizes on (1) a strong relationship with outstanding faculty at the University of California-Davis who are experts in high speed fiber-optic networks, (2) the realization that code division multiple access (CDMA) is emerging as a bandwidth enhancing technique for fiber optic networks, (3) the realization that CDMA of sufficient complexity forms the basis for almost unbreakable one-time key transmissions, (4) our concepts for superior components for implementing CDMA, (5) our expertise in semiconductor device processing and (6) our Center for Nano and Microtechnology, which is where the majority of the experimental work was done. Here we present a novel device concept, which will push the limits of current technology, and will simultaneously solve system implementation issues by investigating new state-of-the-art fiber technologies. This will enable the development of secure communication systems for the transmission and reception of messages on deployed commercial fiber optic networks, through the CDMA phase encoding of broad bandwidth pulses. CDMA technology has been developed as a multiplexing technology, much like wavelength division multiplexing (WDM) or time division multiplexing (TDM), to increase the potential number of users on a given communication link. A novel application of the techniques created for CDMA is to generate secure communication through physical layer encoding. Physical layer encoding devices are developed which utilize semiconductor waveguides with fast carrier response times to phase encode spectral components of a secure signal. Current commercial technology, most commonly a spatial light modulator, allows phase codes to be changed at rates of only 10's of Hertz ({approx}25ms response). The use of fast (picosecond to nanosecond) carrier dynamics of semiconductors, as

  9. Performance enhancement of MC-CDMA system through novel sensitive bit algorithm aided turbo multi user detection.

    PubMed

    Kumaravel, Rasadurai; Narayanaswamy, Kumaratharan

    2015-01-01

    Multi carrier code division multiple access (MC-CDMA) system is a promising multi carrier modulation (MCM) technique for high data rate wireless communication over frequency selective fading channels. MC-CDMA system is a combination of code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM). The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization. Advantages of this technique are its robustness in case of multipath propagation and improve security with the minimize ISI. Nevertheless, due to the loss of orthogonality at the receiver in a mobile environment, the multiple access interference (MAI) appears. The MAI is one of the factors that degrade the bit error rate (BER) performance of MC-CDMA system. The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects. In this paper a low complexity iterative soft sensitive bits algorithm (SBA) aided logarithmic-Maximum a-Posteriori algorithm (Log MAP) based turbo MUD is proposed. Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI. PMID:25714917

  10. Performance enhancement of MC-CDMA system through novel sensitive bit algorithm aided turbo multi user detection.

    PubMed

    Kumaravel, Rasadurai; Narayanaswamy, Kumaratharan

    2015-01-01

    Multi carrier code division multiple access (MC-CDMA) system is a promising multi carrier modulation (MCM) technique for high data rate wireless communication over frequency selective fading channels. MC-CDMA system is a combination of code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM). The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization. Advantages of this technique are its robustness in case of multipath propagation and improve security with the minimize ISI. Nevertheless, due to the loss of orthogonality at the receiver in a mobile environment, the multiple access interference (MAI) appears. The MAI is one of the factors that degrade the bit error rate (BER) performance of MC-CDMA system. The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects. In this paper a low complexity iterative soft sensitive bits algorithm (SBA) aided logarithmic-Maximum a-Posteriori algorithm (Log MAP) based turbo MUD is proposed. Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI.

  11. Performance Enhancement of MC-CDMA System through Novel Sensitive Bit Algorithm Aided Turbo Multi User Detection

    PubMed Central

    Kumaravel, Rasadurai; Narayanaswamy, Kumaratharan

    2015-01-01

    Multi carrier code division multiple access (MC-CDMA) system is a promising multi carrier modulation (MCM) technique for high data rate wireless communication over frequency selective fading channels. MC-CDMA system is a combination of code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM). The OFDM parts reduce multipath fading and inter symbol interference (ISI) and the CDMA part increases spectrum utilization. Advantages of this technique are its robustness in case of multipath propagation and improve security with the minimize ISI. Nevertheless, due to the loss of orthogonality at the receiver in a mobile environment, the multiple access interference (MAI) appears. The MAI is one of the factors that degrade the bit error rate (BER) performance of MC-CDMA system. The multiuser detection (MUD) and turbo coding are the two dominant techniques for enhancing the performance of the MC-CDMA systems in terms of BER as a solution of overcome to MAI effects. In this paper a low complexity iterative soft sensitive bits algorithm (SBA) aided logarithmic-Maximum a-Posteriori algorithm (Log MAP) based turbo MUD is proposed. Simulation results show that the proposed method provides better BER performance with low complexity decoding, by mitigating the detrimental effects of MAI. PMID:25714917

  12. Alternative multiple-access techniques for mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Smith, Patrick O.; Geraniotis, Evaggelos

    1989-01-01

    The use of Code Division Multiple Access (CDMA) to satisfy the diverse requirements of a generic (land, maritime, aeronautical) mobile satellite system (MSS) network design is discussed. Comparisons between CDMA and Frequency Division Multiple Access (FDMA) show that a CDMA network design can support significantly more voice channel allocations than FDMA when relatively simple CDMA correlation receivers are employed, provided that there is sufficient space segment equivalent isotropically radiated power (EIRP). The use of more advanced CDMA receivers can improve the spectral and power efficiency. Although the use of CDMA may not gain immediate and widespread support in the international MSS community, provision for the use of CDMA for a domestic system in the U.S., and possibly for a regional system throughout North America, is likely.

  13. Bit Error Rate Analysis for MC-CDMA Systems in Nakagami-[InlineEquation not available: see fulltext.] Fading Channels

    NASA Astrophysics Data System (ADS)

    Li, Zexian; Latva-aho, Matti

    2004-12-01

    Multicarrier code division multiple access (MC-CDMA) is a promising technique that combines orthogonal frequency division multiplexing (OFDM) with CDMA. In this paper, based on an alternative expression for the[InlineEquation not available: see fulltext.]-function, characteristic function and Gaussian approximation, we present a new practical technique for determining the bit error rate (BER) of multiuser MC-CDMA systems in frequency-selective Nakagami-[InlineEquation not available: see fulltext.] fading channels. The results are applicable to systems employing coherent demodulation with maximal ratio combining (MRC) or equal gain combining (EGC). The analysis assumes that different subcarriers experience independent fading channels, which are not necessarily identically distributed. The final average BER is expressed in the form of a single finite range integral and an integrand composed of tabulated functions which can be easily computed numerically. The accuracy of the proposed approach is demonstrated with computer simulations.

  14. Blind ICA detection based on second-order cone programming for MC-CDMA systems

    NASA Astrophysics Data System (ADS)

    Jen, Chih-Wei; Jou, Shyh-Jye

    2014-12-01

    The multicarrier code division multiple access (MC-CDMA) technique has received considerable interest for its potential application to future wireless communication systems due to its high data rate. A common problem regarding the blind multiuser detectors used in MC-CDMA systems is that they are extremely sensitive to the complex channel environment. Besides, the perturbation of colored noise may negatively affect the performance of the system. In this paper, a new coherent detection method will be proposed, which utilizes the modified fast independent component analysis (FastICA) algorithm, based on approximate negentropy maximization that is subject to the second-order cone programming (SOCP) constraint. The aim of the proposed coherent detection is to provide robustness against small-to-medium channel estimation mismatch (CEM) that may arise from channel frequency response estimation error in the MC-CDMA system, which is modulated by downlink binary phase-shift keying (BPSK) under colored noise. Noncoherent demodulation schemes are preferable to coherent demodulation schemes, as the latter are difficult to implement over time-varying fading channels. Differential phase-shift keying (DPSK) is therefore the natural choice for an alternative modulation scheme. Furthermore, the new blind differential SOCP-based ICA (SOCP-ICA) detection without channel estimation and compensation will be proposed to combat Doppler spread caused by time-varying fading channels in the DPSK-modulated MC-CDMA system under colored noise. In this paper, numerical simulations are used to illustrate the robustness of the proposed blind coherent SOCP-ICA detector against small-to-medium CEM and to emphasize the advantage of the blind differential SOCP-ICA detector in overcoming Doppler spread.

  15. High speed OFDM-CDMA optical access network.

    PubMed

    Guo, X; Wang, Q; Zhou, L; Fang, L; Wonfor, A; Penty, R V; White, I H

    2016-04-15

    We demonstrate the feasibility of a 16 × 3.75 Gb/s (60 Gb/s aggregate) Orthogonal frequency division multiplexing-code division multiple access passive optical network for next-generation access applications. 3.75 Gb/s PON channel transmission over 25 km single-mode fiber shows 0.1 dB dispersion and 0.9 dB crosstalk penalties. Advantages of the system include high capacity, enhanced spectral efficiency, coding gain, and networking functions such as increased security and single-wavelength operation.

  16. RBF multiuser detector with channel estimation capability in a synchronous MC-CDMA system.

    PubMed

    Ko, K; Choi, S; Kang, C; Hong, D

    2001-01-01

    The authors propose a multiuser detector with channel estimation capability using a radial basis function (RBF) network in a synchronous multicarrier-code division multiple access (MC-CDMA) system. The authors propose to connect an RBF network to the frequency domain to effectively utilize the frequency diversity. Simulations were performed over frequency-selective and multi-path fading channels. These simulations confirmed that the proposed receiver can be used both for the channel estimation and as a multi-user receiver, thus permitting an increase in the number of active users. PMID:18249987

  17. Performance of a serial-search synchronizer for fiber-based optical CDMA systems in the presence of multiuser interference

    NASA Astrophysics Data System (ADS)

    Mustapha, Mazlyn M.; Ormondroyd, Richard F.

    1999-11-01

    This paper examines the performance of a serial-search synchronization system in the presence of multiple access interference and receiver noise for a non-coherent fiber- based optical CDMA system using optically orthogonal codes. The synchronization performance of two different optical CDMA system, an on-off keyed system and an M-ary pulse- position modulation system with M equals 2, are compared. The effects of the dwell-time, the total number of users, the code weight, decision threshold and optical hard-limiters on the mean acquisition time of the synchronizer are examined. It is shown that an optimum dwell-time exist which minimizes the mean acquisition time.

  18. Improving performance of DS-CDMA systems using chaotic complex Bernoulli spreading codes

    NASA Astrophysics Data System (ADS)

    Farzan Sabahi, Mohammad; Dehghanfard, Ali

    2014-12-01

    The most important goal of spreading spectrum communication system is to protect communication signals against interference and exploitation of information by unintended listeners. In fact, low probability of detection and low probability of intercept are two important parameters to increase the performance of the system. In Direct Sequence Code Division Multiple Access (DS-CDMA) systems, these properties are achieved by multiplying the data information in spreading sequences. Chaotic sequences, with their particular properties, have numerous applications in constructing spreading codes. Using one-dimensional Bernoulli chaotic sequence as spreading code is proposed in literature previously. The main feature of this sequence is its negative auto-correlation at lag of 1, which with proper design, leads to increase in efficiency of the communication system based on these codes. On the other hand, employing the complex chaotic sequences as spreading sequence also has been discussed in several papers. In this paper, use of two-dimensional Bernoulli chaotic sequences is proposed as spreading codes. The performance of a multi-user synchronous and asynchronous DS-CDMA system will be evaluated by applying these sequences under Additive White Gaussian Noise (AWGN) and fading channel. Simulation results indicate improvement of the performance in comparison with conventional spreading codes like Gold codes as well as similar complex chaotic spreading sequences. Similar to one-dimensional Bernoulli chaotic sequences, the proposed sequences also have negative auto-correlation. Besides, construction of complex sequences with lower average cross-correlation is possible with the proposed method.

  19. A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems.

    PubMed

    Luo, Zhongqiang; Zhu, Lidong

    2015-01-01

    In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low. PMID:26287209

  20. A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems.

    PubMed

    Luo, Zhongqiang; Zhu, Lidong

    2015-08-14

    In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low.

  1. A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems

    PubMed Central

    Luo, Zhongqiang; Zhu, Lidong

    2015-01-01

    In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low. PMID:26287209

  2. Joint Impact of Frequency Synchronization Errors and Intermodulation Distortion on the Performance of Multicarrier DS-CDMA Systems

    NASA Astrophysics Data System (ADS)

    Rugini, Luca; Banelli, Paolo

    2005-12-01

    The performance of multicarrier systems is highly impaired by intercarrier interference (ICI) due to frequency synchronization errors at the receiver and by intermodulation distortion (IMD) introduced by a nonlinear amplifier (NLA) at the transmitter. In this paper, we evaluate the bit-error rate (BER) of multicarrier direct-sequence code-division multiple-access (MC-DS-CDMA) downlink systems subject to these impairments in frequency-selective Rayleigh fading channels, assuming quadrature amplitude modulation (QAM). The analytical findings allow to establish the sensitivity of MC-DS-CDMA systems to carrier frequency offset (CFO) and NLA distortions, to identify the maximum CFO that is tolerable at the receiver side in different scenarios, and to find out the optimum value of the NLA output power backoff for a given CFO. Simulation results show that the approximated analysis is quite accurate in several conditions.

  3. Radio resource management for CDMA systems with interference guard margin (IGM)

    NASA Astrophysics Data System (ADS)

    Chen, Huan; Kumar, Sunil; Kuo, C.-C. Jay

    2001-11-01

    A call admission control (CAC) scheme and a resource reservation estimation (RRE) method suitable for the wide-band code division multiple access (W-CDMA) systems are proposed in this work. The proposed CAC scheme gives preferential treatment to high priority calls, such as handoff calls, by pre-reserving a certain amount of channel margin against the interference effect. It is called the interference guard margin (IGM) scheme. The amount of guard margin is determined by the measurement performed by the RRE module in base stations. Each RRE module dynamically adjusts the level of guard margin by referencing traffic conditions in neighboring cells based upon users' requests. A comprehensive service model is adopted to accommodate the scenario of multiple services supported in the W-CDMA system. The service model of consideration includes not only mobile terminal's service rate (source rate) but also different levels of priorities, mobility and rate adaptivity characteristics. Simulations are conducted with OPNET to study the performance of the proposed scheme in term of the objective function under different traffic conditions.

  4. Handover aspects for a Low Earth Orbit (LEO) CDMA Land Mobile Satellite (LMS) system

    NASA Technical Reports Server (NTRS)

    Carter, P.; Beach, M. A.

    1993-01-01

    This paper addresses the problem of handoff in a land mobile satellite (LMS) system between adjacent satellites in a low earth orbit (LEO) constellation. In particular, emphasis is placed on the application of soft handoff in a direct sequence code division multiple access (DS-CDMA) LMS system. Soft handoff is explained in terms of terrestrial macroscopic diversity, in which signals transmitted via several independent fading paths are combined to enhance the link quality. This concept is then reconsidered in the context of a LEO LMS system. A two-state Markov channel model is used to simulate the effects of shadowing on the communications path from the mobile to each satellite during handoff. The results of the channel simulation form a platform for discussion regarding soft handoff, highlighting the potential merits of the scheme when applied in a LEO LMS environment.

  5. Improved Iterative Parallel Interference Cancellation Receiver for Future Wireless DS-CDMA Systems

    NASA Astrophysics Data System (ADS)

    Morosi, Simone; Fantacci, Romano; Bernacchioni, Andrea

    2005-12-01

    We present a new turbo multiuser detector for turbo-coded direct sequence code division multiple access (DS-CDMA) systems. The proposed detector is based on the utilization of a parallel interference cancellation (PIC) and a bank of turbo decoders. The PIC is broken up in order to perform interference cancellation after each constituent decoder of the turbo decoding scheme. Moreover, in the paper we propose a new enhanced algorithm that provides a more accurate estimation of the signal-to-noise-plus-interference-ratio used in the tentative decision device and in the MAP decoding algorithm. The performance of the proposed receiver is evaluated by means of computer simulations for medium to very high system loads, in AWGN and multipath fading channel, and compared to recently proposed interference cancellation-based iterative MUD, by taking into account the number of iterations and the complexity involved. We will see that the proposed receiver outperforms the others especially for highly loaded systems.

  6. Call admission control for CDMA systems with Interference Guard Margin (IGM)

    NASA Astrophysics Data System (ADS)

    Chen, Huan; Kumar, Sunil; Kuo, C.-C. Jay

    2002-01-01

    A call admission control (CAC) scheme and a resource-reservation estimation (RRE) method suitable for the interference-based wireless system, such as wide-band code division multiple access (W-CDMA), are proposed in this work. The proposed CAC scheme gives preferential treatment to high priority handoff calls by pre-reserving a certain amount of interference margin called the interference guard margin (IGM). The amount of guard margin is determined by the measurement performed by the RRE module in base stations. Each RRE module dynamically adjusts the level of guard margin by considering traffic conditions in neighboring cells based upon handoff requests. A service model is adopted to support multiple services, which includes mobile terminal's data rate, different levels of priorities, mobility and rate adaptivity characteristics. Simulations are conducted with OPNET to study the performance of the proposed scheme in terms of the objective function, blocking probabilities and system utilization under different traffic conditions.

  7. Development of a mobile emergency patient information and imaging communication system based on CDMA-1X EVDO

    NASA Astrophysics Data System (ADS)

    Yang, Keon Ho; Jung, Haijo; Kang, Won-Suk; Jang, Bong Mun; Kim, Joong Il; Han, Dong Hoon; Yoo, Sun-Kook; Yoo, Hyung-Sik; Kim, Hee-Joung

    2006-03-01

    The wireless mobile service with a high bit rate using CDMA-1X EVDO is now widely used in Korea. Mobile devices are also increasingly being used as the conventional communication mechanism. We have developed a web-based mobile system that communicates patient information and images, using CDMA-1X EVDO for emergency diagnosis. It is composed of a Mobile web application system using the Microsoft Windows 2003 server and an internet information service. Also, a mobile web PACS used for a database managing patient information and images was developed by using Microsoft access 2003. A wireless mobile emergency patient information and imaging communication system is developed by using Microsoft Visual Studio.NET, and JPEG 2000 ActiveX control for PDA phone was developed by using the Microsoft Embedded Visual C++. Also, the CDMA-1X EVDO is used for connections between mobile web servers and the PDA phone. This system allows fast access to the patient information database, storing both medical images and patient information anytime and anywhere. Especially, images were compressed into a JPEG2000 format and transmitted from a mobile web PACS inside the hospital to the radiologist using a PDA phone located outside the hospital. Also, this system shows radiological images as well as physiological signal data, including blood pressure, vital signs and so on, in the web browser of the PDA phone so radiologists can diagnose more effectively. Also, we acquired good results using an RW-6100 PDA phone used in the university hospital system of the Sinchon Severance Hospital in Korea.

  8. Intercarrier interference reduction in MC-CDMA system through second order duobinary coded phase rotated conjugate cancellation scheme.

    PubMed

    Chitra, S; Kumaratharan, N

    2015-01-01

    Multi-carrier code division multiple access (MC-CDMA) technique is one of the strong candidates for next generation wireless mobile communication systems. Multi-carrier systems are very much sensitive to carrier frequency offset (CFO) results in intercarrier interference (ICI). To mitigate ICI without any spectral loss, a second order duobinary coded phase rotated conjugate cancellation algorithm is proposed in this paper. In the conventional phase rotated conjugate cancellation (PRCC) technique, one path carries the MC-CDMA signal with a phase spin of ϕ and the other path carries the conjugate of the first path signal with -ϕ phase spin. This artificial phase rotation allows the transmitter to tune the transmitted signals so that the ICI effects could be mutually cancelled at the receiver. Although the PRCC technique reduces the spectral efficiency, the limitation can be overcome by the joint second order duobinary coding scheme with PRCC technique. In the proposed method, the correlative coding between the binary symbols modulated on adjacent subcarriers is used to reduce the ICI without any spectral loss. Simulation results show that the proposed PRCC method provides better carrier to interference ratio (CIR) and bit error rate (BER) performances compared to the conventional conjugate cancellation (CC) technique.

  9. Intercarrier Interference Reduction in MC-CDMA System through Second Order Duobinary Coded Phase Rotated Conjugate Cancellation Scheme

    PubMed Central

    Chitra, S.; Kumaratharan, N.

    2015-01-01

    Multi-carrier code division multiple access (MC-CDMA) technique is one of the strong candidates for next generation wireless mobile communication systems. Multi-carrier systems are very much sensitive to carrier frequency offset (CFO) results in intercarrier interference (ICI). To mitigate ICI without any spectral loss, a second order duobinary coded phase rotated conjugate cancellation algorithm is proposed in this paper. In the conventional phase rotated conjugate cancellation (PRCC) technique, one path carries the MC-CDMA signal with a phase spin of ϕ and the other path carries the conjugate of the first path signal with -ϕ phase spin. This artificial phase rotation allows the transmitter to tune the transmitted signals so that the ICI effects could be mutually cancelled at the receiver. Although the PRCC technique reduces the spectral efficiency, the limitation can be overcome by the joint second order duobinary coding scheme with PRCC technique. In the proposed method, the correlative coding between the binary symbols modulated on adjacent subcarriers is used to reduce the ICI without any spectral loss. Simulation results show that the proposed PRCC method provides better carrier to interference ratio (CIR) and bit error rate (BER) performances compared to the conventional conjugate cancellation (CC) technique. PMID:25790029

  10. Why is CDMA the solution for mobile satellite communication

    NASA Technical Reports Server (NTRS)

    Gilhousen, Klein S.; Jacobs, Irwin M.; Padovani, Roberto; Weaver, Lindsay A.

    1989-01-01

    It is demonstrated that spread spectrum Code Division Multiple Access (CDMA) systems provide an economically superior solution to satellite mobile communications by increasing the system maximum capacity with respect to single channel per carrier Frequency Division Multiple Access (FDMA) systems. Following the comparative analysis of CDMA and FDMA systems, the design of a model that was developed to test the feasibility of the approach and the performance of a spread spectrum system in a mobile environment. Results of extensive computer simulations as well as laboratory and field tests results are presented.

  11. Performance improvement with hybrid WDM and CDMA optical communications

    NASA Astrophysics Data System (ADS)

    Gagliardi, Robert M.; Mendez, Antonio J.

    1996-05-01

    It is well known that either Wavelength Division Multiplexing (WDM) or pulsed Code Division Multiple Accessing (CDMA) can be used as a basic accessing format in structuring an optical communication network or high speed parallel data processor. Each such system has its own inherent advantages and disadvantages when used as the principle format. When the two concepts are combined into a single hybrid WDM/CDMA format, some of the disadvantages of each format can be offset by the presence of the other, producing a more robust networking system with improved communication performance. In this paper these hybrid concepts are presented, and some of their hardware and architecture impacts are developed.

  12. Satellite multiple access systems for mobile communication

    NASA Technical Reports Server (NTRS)

    Lewis, J. L.

    1979-01-01

    This paper considers multiple access techniques for a mobile radio system which incorporates a geosynchronous orbiting satellite repeater through which mobile terminals communicate. The communication capacities of FDMA, TDMA and CDMA systems are examined for a 4 MHz bandwidth system to serve up to 10,000 users. An FDMA system with multibeam coverage is analyzed in detail. The system includes an order-wire network for demand-access control and reassignment of satellite channels. Satellite and terminal configurations are developed to a block diagram level and system costs and implementation requirements are discussed.

  13. Efficiency droop effects of GaN-based light-emitting diodes on the performance of code division multiple access visible-light communication system

    NASA Astrophysics Data System (ADS)

    Lu, Huimin; Yan, Chaowen; Gao, Wei; Yu, Tongjun; Wang, Jianping

    2016-02-01

    The physical mechanism in efficiency droop of GaN-based light-emitting diodes (LEDs) was investigated using a modified rate equation model considering inhomogeneous carrier distribution and was compared with the measured result. On this basis, the efficiency droop effect on the performance of a code division multiple access (CDMA) visible-light communication (VLC) system using GaN-based LEDs was also analyzed. The results reveal that the obvious transmitted signal error under the effect of LED efficiency droop leads to performance deterioration of multiuser CDMA VLC systems. Also, the performance of CDMA VLC systems is reduced with the user number increase due to LED efficiency droop. The bit error rate of a CDMA VLC system was further calculated for different branch signal levels and bias currents. It is demonstrated that the efficiency droop effect on the performance of CDMA VLC systems can be alleviated by adjusting the branch signal level and the bias current.

  14. Design and Evaluation of a Virtual Quadrant Receiver for 4-ary Pulse Position Modulation/Optical Code Division Multiple Access (4-ary PPM/O-CDMA)

    SciTech Connect

    Mendez, A J; Hernandez, V J; Gagliardi, R M; Bennett, C V

    2006-12-29

    M-ary pulse position modulation (M-ary PPM) is an alternative to on-off-keying (OOK) that transmits multiple bits as a single symbol occupying a frame of M slots. PPM does not require thresholding as in OOK signaling, instead performing a comparison test among all slots in a frame to make the slot decision. Combining PPM with optical code division multiple access (PPM/O-CDMA) adds the benefit of supporting multiple concurrent, asynchronous bursty PPM users. While the advantages of PPM/O-CDMA are well known, implementing a receiver that performs comparison test can be difficult. This paper describes the design of a novel array receiver for M-ary PPM/O-CDMA (M = 4) where the received signal is mapped onto an xy-plane whose quadrants define the PPM slot decision by means of an associated control law. The receiver does not require buffering or nonlinear operations. In this paper we describe a planar lightwave circuit (PLCs) implementation of the receiver. We give detailed numerical simulations that test the concept and investigate the effects of multi-access interference (MAI) and optical beat interference (OBI) on the slot decisions. These simulations provide guidelines for subsequent experimental measurements that will be described.

  15. A CDMA synchronisation scheme

    NASA Technical Reports Server (NTRS)

    Soprano, C.

    1993-01-01

    CDMA (Code Division Multiple Access) is known to decrease inter-service interference in Satellite Communication Systems. Its performance is increased by chip quasi-synchronous operation which virtually eliminates the self-noise; however, the theory shows that the time error on the synchronization has to be kept at less than one tenth of a chip which, for 1 Mchip/sec. spreading rate, corresponds to 10(exp -7) sec. This, on the return-link, may only be achieved by means of a closed loop control system which, for mobile communication systems, has to be capable of autonomous operation. Until now some results have been reported on the feasibility of chip quasi-synchronous operation for mobile communication systems only including satellites on GEO (Geostationary Earth Orbit). In what follows, the basic principles are exposed, and results are presented showing how low chip synchronism error may be achieved by means of an autonomous control loop operating through satellites on any Earth orbit.

  16. Space-Time Coded MC-CDMA: Blind Channel Estimation, Identifiability, and Receiver Design

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Li, Hongbin

    2003-12-01

    Integrating the strengths of multicarrier (MC) modulation and code division multiple access (CDMA), MC-CDMA systems are of great interest for future broadband transmissions. This paper considers the problem of channel identification and signal combining/detection schemes for MC-CDMA systems equipped with multiple transmit antennas and space-time (ST) coding. In particular, a subspace based blind channel identification algorithm is presented. Identifiability conditions are examined and specified which guarantee unique and perfect (up to a scalar) channel estimation when knowledge of the noise subspace is available. Several popular single-user based signal combining schemes, namely the maximum ratio combining (MRC) and the equal gain combining (EGC), which are often utilized in conventional single-transmit-antenna based MC-CDMA systems, are extended to the current ST-coded MC-CDMA (STC-MC-CDMA) system to perform joint combining and decoding. In addition, a linear multiuser minimum mean-squared error (MMSE) detection scheme is also presented, which is shown to outperform the MRC and EGC at some increased computational complexity. Numerical examples are presented to evaluate and compare the proposed channel identification and signal detection/combining techniques.

  17. Advanced multiple access concepts in mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Ananasso, Fulvio

    1990-01-01

    Some multiple access strategies for Mobile Satellite Systems (MSS) are discussed. These strategies were investigated in the context of three separate studies conducted for the International Maritime Satellite Organization (INMARSAT) and the European Space Agency (ESA). Satellite-Switched Frequency Division Multiple Access (SS-FDMA), Code Division Multiple Access (CDMA), and Frequency-Addressable Beam architectures are addressed, discussing both system and technology aspects and outlining advantages and drawbacks of either solution with associated relevant hardware issues. An attempt is made to compare the considered option from the standpoint of user terminal/space segment complexity, synchronization requirements, spectral efficiency, and interference rejection.

  18. Comparison of FDMA and CDMA for second generation land-mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Yongacoglu, A.; Lyons, R. G.; Mazur, B. A.

    1990-01-01

    Code Division Multiple Access (CDMA) and Frequency Division Multiple Access (FDMA) (both analog and digital) systems capacities are compared on the basis of identical link availabilities and physical propagation models. Parameters are optimized for a bandwidth limited, multibeam environment. For CDMA, the benefits of voice activated carriers, antenna discrimination, polarization reuse, return link power control and multipath suppression are included in the analysis. For FDMA, the advantages of bandwidth efficient modulation/coding combinations, voice activated carriers, polarization reuse, beam placement, and frequency staggering were taken into account.

  19. A CDMA Spotbeam Architecture for the Next Generation Satellite System (NGSS) for the Aeronautical Telecommunications Network (ATN)

    NASA Technical Reports Server (NTRS)

    Raghavan, Rajesh S.; Shamma, Mohammed A.

    2003-01-01

    This paper will present work being done to model and simulate a CDMA based Mobile Satellite System architecture for providing all or part of the future Air Traffic Management (ATM) services. Such a system, will help in relieving the dependence on ground based networks, if not eliminate it. Additionally such an architecture can be used in parallel or as a supplementary service along with ground based links to help alleviate any capacity bottlenecks, or in areas where such services are difficult to make available such as in oceanic, remote areas outside the jet highways, or in developing countries where ground services are less available.

  20. Performance improvement of FSO/CDMA systems over dispersive turbulence channel using multi-wavelength PPM signaling.

    PubMed

    Dang, Ngoc T; Pham, Anh T

    2012-11-19

    Previous studies show that, compared to on-off keying (OOK) signaling, pulse-position modulation (PPM) is favorable in FSO/CDMA systems thanks to its energy efficiency and simple detection. Nevertheless, when the system bit rate increases and the transmission distance is far, the FSO/CDMA systems using PPM signaling critically suffer from the impact of pulse broadening caused by dispersion, especially when the modulation level is high. In this paper, we therefore propose to use multi-wavelength PPM (MWPPM) signaling to overcome the limitation of PPM. To further improve the system performance, avalanche photodiode (APD) is also used. The performance of the proposed system is theoretically analyzed using a realistic model of Gaussian pulse propagation. To model the impact of intensity fluctuation caused by the atmospheric turbulence, the log-normal channel is used. We find that, by using MWPPM, the effects of both intensity fluctuation and pulse broadening are mitigated, the BER is therefore significantly improved. Additionally, we quantitatively show that the system performance is further improved by using APD, especially when the average APD gain is chosen properly.

  1. Adaptive digital beamforming for a CDMA mobile communications payload

    NASA Technical Reports Server (NTRS)

    Munoz-Garcia, Samuel G.; Ruiz, Javier Benedicto

    1993-01-01

    In recent years, Spread-Spectrum Code Division Multiple Access (CDMA) has become a very popular access scheme for mobile communications due to a variety of reasons: excellent performance in multipath environments, high scope for frequency reuse, graceful degradation near saturation, etc. In this way, a CDMA system can support simultaneous digital communication among a large community of relatively uncoordinated users sharing a given frequency band. Nevertheless, there are also important problems associated with the use of CDMA. First, in a conventional CDMA scheme, the signature sequences of asynchronous users are not orthogonal and, as the number of active users increases, the self-noise generated by the mutual interference between users considerably degrades the performance, particularly in the return link. Furthermore, when there is a large disparity in received powers - due to differences in slant range or atmospheric attenuation - the non-zero cross-correlation between the signals gives rise to the so-called near-far problem. This leads to an inefficient utilization of the satellite resources and, consequently, to a drastic reduction in capacity. Several techniques were proposed to overcome this problem, such as Synchronized CDMA - in which the signature sequences of the different users are quasi-orthogonal - and power control. At the expense of increased network complexity and user coordination, these techniques enable the system capacity to be restored by equitably sharing the satellite resources among the users. An alternative solution is presented based upon the use of time-reference adaptive digital beamforming on board the satellite. This technique enables a high number of independently steered beams to be generated from a single phased array antenna, which automatically track the desired user signal and null the unwanted interference source. In order to use a time-reference adaptive antenna in a communications system, the main challenge is to obtain a

  2. Pilot-aided chip-interleaved DS-CDMA transmission over time-varying channels (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Na, Yanxin; Saquib, Mohammad; Win, Moe Z.

    2005-05-01

    Time-varying multipath fading associated with the wireless link limit the capacity of a wireless system. To adapt to this adverse radio environment efficiently, we investigate the use of a pilot-aided fade-resistant transmission scheme for the uplink of a chip-interleaved code division multiple access (CDMA) system. We analyze the trade-off between the number of diversity branches and the channel estimation error. We derive the optimum ratio of pilot signal power to information signal power. Our numerical study indicates that depending on the transmitter power and channel condition, the proposed system is capable of outperforming the conventional CDMA system.

  3. A Review on Successive Interference Cancellation Scheme Based on Optical CDMA Network

    NASA Astrophysics Data System (ADS)

    Alsowaidi, N.; Eltaif, T.; Mokhtar, M. R.

    2014-12-01

    Due to various desirable features of optical code division multiple access (OCDMA), it is believed this technique once developed and commercially available will be an integral part of optical access networks. Optical CDMA system suffers from a problem called multiple access interference (MAI) which limits the number of active users, it occurs when number of active users share the same carriers. The aim of this paper is to review successive interference cancellation (SIC) scheme based on optical CDMA system. The paper also reviews the system performance in presence of shot noise, thermal noise, and phase-induced intensity noise (PIIN). A comprehensive review on the mathematical model of SIC scheme using direct detection (DS) and spectral amplitude coding (SAC) were presented in this article.

  4. Performance of Reverse-Link Synchronous DS-CDMA System on a Frequency-Selective Multipath Fading Channel with Imperfect Power Control

    NASA Astrophysics Data System (ADS)

    Hwang, Seung-Hoon; Kim, Duk Kyung

    2002-12-01

    We analyze the performance for reverse-link synchronous DS-CDMA system in a frequency-selective Rayleigh fading channel with an imperfect power control scheme. The performance degradation due to power control error (PCE), which is approximated by a log-normally distributed random variable, is estimated as a function of the standard deviation of the PCE. In addition, we investigate the impacts of the multipath intensity profile (MIP) shape and the number of resolvable paths on the performance. Finally, the coded bit error performance is evaluated in order to estimate the system capacity. Comparing with the conventional CDMA system, we show an achievable gain of from 59% to 23% for reverse-link synchronous transmission technique (RLSTT) in the presence of imperfect power control over asynchronous transmission for[InlineEquation not available: see fulltext.]. As well, the effect of tradeoff between orthogonality and diversity can be seen according to the number of multipaths, and the tendency is kept even in the presence of PCE. We conclude that the capacity can be further improved via the RLSTT, because the DS-CDMA system is very sensitive to power control imperfections.

  5. Successive Interference Cancellation for DS-Optical PPM-CDMA Systems

    NASA Astrophysics Data System (ADS)

    Alsowaidi, N.; Eltaif, Tawfig; Mokhtar, M. R.

    2016-06-01

    In this paper we introduce a successive interference cancellation (SIC) scheme for direct sequence optical code division multiple access (DS-OCDMA) systems using pulse position modulation (PPM). Considering double-padded modified prime code (DPMPC) as a signature sequence code, results show that the system has better performance in terms of both capacity and bit error rate (BER) as compared to the one without cancellation scheme, where the system with SIC scheme can support up to 88 users while the system without SIC scheme can support only 38 users at similar BER=10-9. Although the receiver sensitivity is affected by the overlapping between users, which limits the system performance, the theoretical analysis of this issue indicates the influence of the size of M-ary PPM on OCDMA system. Hence, the BER value is still sufficient for good system performance.

  6. A discussion on mobile satellite system and the myths of CDMA and diversity revealed

    NASA Technical Reports Server (NTRS)

    Hart, Nicholas; Goerke, Thomas; Jahn, Axel

    1995-01-01

    The paper explores the myths and facts surrounding: link margins and constellation designs; the use of satellite diversity in a mobile satellite channel; trade-offs in multiple access technique. Different satellite constellations are presented, which are comparable with those used by the big LEO proponents, with the associated trade-offs in the system design. Propagation data and results from various narrowband and wideband measurement campaigns are used to illustrate the expected differences in service performance.

  7. Distributed magnetic field positioning system using code division multiple access

    NASA Technical Reports Server (NTRS)

    Prigge, Eric A. (Inventor)

    2003-01-01

    An apparatus and methods for a magnetic field positioning system use a fundamentally different, and advantageous, signal structure and multiple access method, known as Code Division Multiple Access (CDMA). This signal architecture, when combined with processing methods, leads to advantages over the existing technologies, especially when applied to a system with a large number of magnetic field generators (beacons). Beacons at known positions generate coded magnetic fields, and a magnetic sensor measures a sum field and decomposes it into component fields to determine the sensor position and orientation. The apparatus and methods can have a large `building-sized` coverage area. The system allows for numerous beacons to be distributed throughout an area at a number of different locations. A method to estimate position and attitude, with no prior knowledge, uses dipole fields produced by these beacons in different locations.

  8. Performance Analysis of SAC Optical PPM-CDMA System-Based Interference Rejection Technique

    NASA Astrophysics Data System (ADS)

    Alsowaidi, N.; Eltaif, Tawfig; Mokhtar, M. R.

    2016-03-01

    In this paper, we aim to theoretically analyse optical code division multiple access (OCDMA) system that based on successive interference cancellation (SIC) using pulse position modulation (PPM), considering the interference between the users, imperfection cancellation occurred during the cancellation process and receiver noises. Spectral amplitude coding (SAC) scheme is used to suppress the overlapping between the users and reduce the receiver noises effect. The theoretical analysis of the multiple access interference (MAI)-limited performance of this approach indicates the influence of the size of M-ary PPM on OCDMA system. The OCDMA system performance improves with increasing M-ary PPM. Therefore, it was found that the SIC/SAC-OCDMA system using PPM technique along with modified prime (MPR) codes used as signature sequence code offers significant improvement over the one without cancellation and it can support up to 103 users at the benchmarking value of bit error rate (BER) = 10-9 with prime number p = 11 while the system without cancellation scheme can support only up to 52 users.

  9. Impairments Computation for Routing Purposes in a Transparent-Access Optical Network Based on Optical CDMA and WDM

    NASA Astrophysics Data System (ADS)

    Musa, Ahmed

    2016-06-01

    Optical access networks are becoming more widespread and the use of multiple services might require a transparent optical network (TON). Multiplexing and privacy could benefit from the combination of wavelength division multiplexing (WDM) and optical coding (OC) and wavelength conversion in optical switches. The routing process needs to be cognizant of different resource types and characteristics such as fiber types, fiber linear impairments such as attenuation, dispersion, etc. as well as fiber nonlinear impairments such as four-wave mixing, cross-phase modulation, etc. Other types of impairments, generated by optical nodes or photonic switches, also affect the signal quality (Q) or the optical signal to noise ratio (OSNR), which is related to the bit error rate (BER). Therefore, both link and switch impairments must be addressed and somehow incorporated into the routing algorithm. However, it is not practical to fully integrate all photonic-specific attributes in the routing process. In this study, new routing parameters and constraints are defined that reflect the distinct characteristics of photonic networking. These constraints are applied to the design phase of TON and expressed as a cost or metric form that will be used in the network routing algorithm.

  10. Effects of electromagnetic fields emitted from W-CDMA-like mobile phones on sleep in humans.

    PubMed

    Nakatani-Enomoto, Setsu; Furubayashi, Toshiaki; Ushiyama, Akira; Groiss, Stefan Jun; Ueshima, Kazumune; Sokejima, Shigeru; Simba, Ally Y; Wake, Kanako; Watanabe, So-ichi; Nishikawa, Masami; Miyawaki, Kaori; Taki, Masao; Ugawa, Yoshikazu

    2013-12-01

    In this study, we investigated subjective and objective effects of mobile phones using a Wideband Code Division Multiple Access (W-CDMA)-like system on human sleep. Subjects were 19 volunteers. Real or sham electromagnetic field (EMF) exposures for 3 h were performed before their usual sleep time on 3 consecutive days. They were exposed to real EMF on the second or third experimental day in a double-blind design. Sleepiness and sleep insufficiency were evaluated the next morning. Polysomnograms were recorded for analyses of the sleep variables and power spectra of electroencephalograms (EEG). No significant differences were observed between the two conditions in subjective feelings. Sleep parameters including sleep stage percentages and EEG power spectra did not differ significantly between real and sham exposures. We conclude that continuous wave EMF exposure for 3 h from a W-CDMA-like system has no detectable effects on human sleep.

  11. PAPR reduction in synchronous CI/MC-CDMA uplink system using genetic algorithms

    NASA Astrophysics Data System (ADS)

    Hati, Sumanta; Maity, Santi P.

    2013-01-01

    Main disadvantage of a multicarrier communication system is high peak to average power ratio (PAPR) of the transmitted signal. The high PAPR causes the performance degradation due to nonlinear distortion in the high power amplifier (HPA). PAPR value is closely depends on transmitted power and correlation properties of the user's spreading code. High peak and low average value of the transmitted power increases the PAPR. On the other side high auto correlation function (ACF) value and low cross correlation function (CCF) value of the spreading code also increases the PAPR. But to eliminate the multiple access interference (MAI) in receiver end, ACF should be peak and CCF should be posses zero for all time shifts. So, there is a conflicting nature of PAPR and bit error rate (BER). That's why an exhaustive effort has been made in this paper for proper distribution of transmitted power within an acceptable range of peak transmitted power and evaluates the new spreading codes using Genetic Algorithms (GA). In general, to obtain optimum PAPR reduction using GA, total searching time to find out the proper amplitude and phase parameters must be accomplished. Simulation results show that PAPR and BER performance using this proposed technique is better than conventional network.

  12. First satellite mobile communication trials using BLQS-CDMA

    NASA Technical Reports Server (NTRS)

    Luzdemateo, Maria; Johns, Simon; Dothey, Michel; Vanhimbeeck, Carl; Deman, Ivan; Wery, Bruno

    1993-01-01

    In this paper, technical results obtained in the first MSBN Land mobile technical trial are reported. MSBN (Mobile Satellite Business Network) is a new program undertaken by the European Space Agency (ESA) to promote mobile satellite communication in Europe, in particular voice capability. The first phase of the MSBN system implementation plan is an experimental phase. Its purpose is to evaluate through field experiments the performance of the MSBN system prior to finalization of its specifications. Particularly, the objective is to verify in the field and possibly improve the performance of the novel satellite access technique BLQS-CDMA (Band Limited Quasi-Synchronous-Code Division Multiple Access), which is proposed as baseline for the MSBN.

  13. Proceedings of the Mobile Satellite System Architectures and Multiple Access Techniques Workshop

    NASA Technical Reports Server (NTRS)

    Dessouky, Khaled

    1989-01-01

    The Mobile Satellite System Architectures and Multiple Access Techniques Workshop served as a forum for the debate of system and network architecture issues. Particular emphasis was on those issues relating to the choice of multiple access technique(s) for the Mobile Satellite Service (MSS). These proceedings contain articles that expand upon the 12 presentations given in the workshop. Contrasting views on Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA)-based architectures are presented, and system issues relating to signaling, spacecraft design, and network management constraints are addressed. An overview article that summarizes the issues raised in the numerous discussion periods of the workshop is also included.

  14. High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

    NASA Astrophysics Data System (ADS)

    Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

    2016-06-01

    Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

  15. Analysis of multiple access techniques in multi-satellite and multi-spot mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Corazza, Giovanni E.; Ferrarelli, Carlo; Vatalaro, Francesco

    1995-01-01

    In this paper the analysis of mobile satellite systems adopting constellations of multi-spot satellites over non-geostationary orbits is addressed. A link design procedure is outlined, taking into account system spectrum efficiency, probability of bit error and outage probability. A semi-analytic approach to the evaluation of outage probability in the presence of fading and imperfect power control is described, and applied to single channel per carrier (SCPC) and code division multiple access (CDMA) techniques. Some results are shown for the Globalstar, Iridium and Odyssey orbital configurations.

  16. Strict optical orthogonal codes for purely asynchronous code-division multiple-access applications.

    PubMed

    Zhang, J G

    1996-12-10

    Strict optical orthogonal codes are presented for purely asynchronous optical code-division multiple-access (CDMA) applications. The proposed code can strictly guarantee the peaks of its cross-correlation functions and the sidelobes of any of its autocorrelation functions to have a value of 1 in purely asynchronous data communications. The basic theory of the proposed codes is given. An experiment on optical CDMA systems is also demonstrated to verify the characteristics of the proposed code.

  17. Ka-band geostationary satellite spacing requirements and access schemes

    NASA Technical Reports Server (NTRS)

    Caron, Mario; Hindson, Daniel J.

    1995-01-01

    Geostationary satellite systems for wideband personal communications applications have been proposed. This paper looks at the geostationary satellite spacing requirement to meet the ITU-R sharing criterion for FDMA and CDMA access schemes. CDMA capacity equation is first developed. Then the basis for the interference analysis between two systems with an overlapping coverage area is developed for the cases of identical and different access schemes and for bandwidth and power limited systems. An example of an interference analysis between two systems is fully carried out. The paper also points out the inherent problems when comparing systems with different access schemes. It is found that under certain scenarios, CDMA can allow a closer spacing between satellites.

  18. Mobile multiple access study

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Multiple access techniques (FDMA, CDMA, TDMA) for the mobile user and attempts to identify the current best technique are discussed. Traffic loading is considered as well as voice and data modulation and spacecraft and system design. Emphasis is placed on developing mobile terminal cost estimates for the selected design. In addition, design examples are presented for the alternative techniques of multiple access in order to compare with the selected technique.

  19. Multiple Access Trade Study

    NASA Technical Reports Server (NTRS)

    Motamedi, Masoud

    1990-01-01

    The Personal Access Satellite System (PASS) strawman design uses a hybrid Time Division Multiple Access (TDMA)/Frequency Division Multiple Access (FDMA) implementation. TDMA is used for the forward direction (from Suppliers to Users), and FDMA for the return direction (from Users to Suppliers). An alternative architecture is proposed that will require minimal real time coordination and yet provide a fast access method by using random access Code Division Multiple Access (CDMA). The CDMA system issues are addressed such as connecting suppliers and users, both of whom may be located anywhere in the CONUS, when the user terminals are constrained in size and weight; and providing efficient traffic routing under highly variable traffic requirements. It is assumed that bandwidth efficiency is not of paramount importance. CDMA or Spread Spectrum Multiple Access (SSMA) communication is a method in which a group of carriers operate at the same nominal center frequency but are separable from each other by the low cross correlation of the spreading codes used. Interference and multipath rejection capability, ease of selective addressing and message screening, low density power spectra for signal hiding and security, and high resolution ranging are among the benefits of spread spectrum communications.

  20. Effects of simultaneous combined exposure to CDMA and WCDMA electromagnetic fields on serum hormone levels in rats.

    PubMed

    Jin, Yeung Bae; Choi, Hyung-Do; Kim, Byung Chan; Pack, Jeong-Ki; Kim, Nam; Lee, Yun-Sil

    2013-05-01

    Despite more than a decade of research on the endocrine system, there have been no published studies about the effects of concurrent exposure of radiofrequency electromagnetic fields (RF-EMF) on this system. The present study investigated the several parameters of the endocrine system including melatonin, thyroid stimulating hormone, stress hormone and sex hormone after code division multiple access (CDMA, 849 MHz) and wideband code division multiple access (WCDMA, 1.95 GHz) signals for simultaneous exposure in rats. Sprague-Dawley rats were exposed to RF-EMF signals for 45 min/day, 5 days/week for up to 8 weeks. The whole-body average specific absorption rate (SAR) of CDMA or WCDMA was 2.0 W/kg (total 4.0 W/kg). At 4 and 8 weeks after the experiment began, each experimental group's 40 rats (male 20, female 20) were autopsied. Exposure for 8 weeks to simultaneous CDMA and WCDMA RF did not affect serum levels in rats of melatonin, thyroid stimulating hormone (TSH), triiodothyronine (T3) and thyroxin (T4), adrenocorticotropic hormone (ACTH) and sex hormones (testosterone and estrogen) as assessed by the ELISA method.

  1. Experimental investigation on the high chip rate of 2D incoherent optical CDMA system

    NASA Astrophysics Data System (ADS)

    Su, Guorui; Wang, Rong; Pu, Tao; Fang, Tao; Zheng, Jilin; Zhu, Huatao; Wu, Weijiang

    2015-08-01

    An innovative approach to realise high chip rate in OCDMA transmission system is proposed and experimentally investigation, the high chip rate is achieved through a 2-D wavelength-hopping time-spreading en/decoder based on the supercontinuum light source. The source used in the experiment is generated by high nonlinear optical fiber (HNLF), Erbium-doped fiber amplifier (EDFA) which output power is 26 dBm, and distributed feed-back laser diode which works in the gain switch state. The span and the flatness of the light source are 20 nm and 3 dB, respectively, after equalization of wavelength selective switch (WSS). The wavelength-hopping time-spreading coder can be changed 20 nm in the wavelength and 400 ps in the time, is consist of WSS and delay lines. Therefore, the experimental results show that the chip rate can achieve 500 Gchip/s, in the case of 2.5 Gbit/s, while keeping a bit error rate below forward error correction limit after 40 km transmission.

  2. Code-division multiple-access multiuser demodulator by using quantum fluctuations.

    PubMed

    Otsubo, Yosuke; Inoue, Jun-Ichi; Nagata, Kenji; Okada, Masato

    2014-07-01

    We examine the average-case performance of a code-division multiple-access (CDMA) multiuser demodulator in which quantum fluctuations are utilized to demodulate the original message within the context of Bayesian inference. The quantum fluctuations are built into the system as a transverse field in the infinite-range Ising spin glass model. We evaluate the performance measurements by using statistical mechanics. We confirm that the CDMA multiuser modulator using quantum fluctuations achieve roughly the same performance as the conventional CDMA multiuser modulator through thermal fluctuations on average. We also find that the relationship between the quality of the original information retrieval and the amplitude of the transverse field is somehow a "universal feature" in typical probabilistic information processing, viz., in image restoration, error-correcting codes, and CDMA multiuser demodulation.

  3. Ultrasonic Array for Obstacle Detection Based on CDMA with Kasami Codes

    PubMed Central

    Diego, Cristina; Hernández, Álvaro; Jiménez, Ana; Álvarez, Fernando J.; Sanz, Rebeca; Aparicio, Joaquín

    2011-01-01

    This paper raises the design of an ultrasonic array for obstacle detection based on Phased Array (PA) techniques, which steers the acoustic beam through the environment by electronics rather than mechanical means. The transmission of every element in the array has been encoded, according to Code Division for Multiple Access (CDMA), which allows multiple beams to be transmitted simultaneously. All these features together enable a parallel scanning system which does not only improve the image rate but also achieves longer inspection distances in comparison with conventional PA techniques. PMID:22247675

  4. A Link-Level Simulator of the cdma2000 Reverse-Link Physical Layer.

    PubMed

    Gharavi, H; Chin, F; Ban, K; Wyatt-Millington, R

    2003-01-01

    The cdma2000 system is an evolutionary enhancement of the IS-95 standards which support 3G services defined by the International Telecommunications Union (ITU). cdma2000 comes in two phases: 1XRTT and 3XRTT (1X and 3X indicates the number of 1.25 MHz wide radio carrier channels used and RTT stands for Radio Transmission Technology). The cdma2000 1XRTT, which operates within a 1.25 MHz bandwidth, can be utilized in existing IS-95 CDMA channels as it uses the same bandwidth, while 3XRTT requires the commitment of 5 MHz bandwidth to support higher data rates. This paper describes a software model implementation of the cdma2000 reverse link and its application for evaluating the effect of rake receiver design parameters on the system performance under various multipath fading conditions. The cdma2000 models were developed at the National Institute of Standards and Technology (NIST), using SPW (Signal Processing Worksystem) commercial software tools. The model has been developed in a generic manner that includes all the reverse link six radio configurations and their corresponding data rates, according to cdma2000 specifications. After briefly reviewing the traffic channel characteristics of the cdma2000 reverse link (subscriber to base station), the paper discusses the rake receiver implementation including an ideal rake receiver. It then evaluates the performance of each receiver for a Spreading Rate 3 (3XRTT) operation, which is considered as a true "3G" cdma2000 technology. These evaluations are based on the vehicular IMT-2000 (International Mobile Telecommunication 2000) channel model using the link budget defined in cdma2000 specifications for the reverse link.

  5. Asynchronous detection of optical code division multiple access signals using a bandwidth-efficient and wavelength-aware receiver.

    PubMed

    Fok, Mable P; Deng, Yanhua; Prucnal, Paul R

    2010-04-01

    We experimentally demonstrate what we believe to be a novel detection scheme for interfacing asynchronous optical code division multiple access (CDMA) signals with an electronic clock and data recovery system that operates only at the baseband bandwidth. This allows using a large optical bandwidth expansion factor in which the optical chip rate is much larger than the bandwidth of the optoelectronic receiver. The received optical CDMA signal is launched into a four-wave-mixing-based wavelength-aware all-optical front end that rejects multiaccess interference, followed by an amplitude-noise suppression stage comprised of a semiconductor optical amplifier. The clean signal is then converted into a non-return-to-zero-like signal by a baseband receiver. Using the proposed detection scheme, asynchronous transmission and detection of optical CDMA signals is implemented. With the novel detection scheme, the classic CDMA near-far problem is mitigated, and error-free detection is easily obtained.

  6. A hybrid path-oriented code assignment CDMA-based MAC protocol for underwater acoustic sensor networks.

    PubMed

    Chen, Huifang; Fan, Guangyu; Xie, Lei; Cui, Jun-Hong

    2013-11-04

    Due to the characteristics of underwater acoustic channel, media access control (MAC) protocols designed for underwater acoustic sensor networks (UWASNs) are quite different from those for terrestrial wireless sensor networks. Moreover, in a sink-oriented network with event information generation in a sensor field and message forwarding to the sink hop-by-hop, the sensors near the sink have to transmit more packets than those far from the sink, and then a funneling effect occurs, which leads to packet congestion, collisions and losses, especially in UWASNs with long propagation delays. An improved CDMA-based MAC protocol, named path-oriented code assignment (POCA) CDMA MAC (POCA-CDMA-MAC), is proposed for UWASNs in this paper. In the proposed MAC protocol, both the round-robin method and CDMA technology are adopted to make the sink receive packets from multiple paths simultaneously. Since the number of paths for information gathering is much less than that of nodes, the length of the spreading code used in the POCA-CDMA-MAC protocol is shorter greatly than that used in the CDMA-based protocols with transmitter-oriented code assignment (TOCA) or receiver-oriented code assignment (ROCA). Simulation results show that the proposed POCA-CDMA-MAC protocol achieves a higher network throughput and a lower end-to-end delay compared to other CDMA-based MAC protocols.

  7. A Hybrid Path-Oriented Code Assignment CDMA-Based MAC Protocol for Underwater Acoustic Sensor Networks

    PubMed Central

    Chen, Huifang; Fan, Guangyu; Xie, Lei; Cui, Jun-Hong

    2013-01-01

    Due to the characteristics of underwater acoustic channel, media access control (MAC) protocols designed for underwater acoustic sensor networks (UWASNs) are quite different from those for terrestrial wireless sensor networks. Moreover, in a sink-oriented network with event information generation in a sensor field and message forwarding to the sink hop-by-hop, the sensors near the sink have to transmit more packets than those far from the sink, and then a funneling effect occurs, which leads to packet congestion, collisions and losses, especially in UWASNs with long propagation delays. An improved CDMA-based MAC protocol, named path-oriented code assignment (POCA) CDMA MAC (POCA-CDMA-MAC), is proposed for UWASNs in this paper. In the proposed MAC protocol, both the round-robin method and CDMA technology are adopted to make the sink receive packets from multiple paths simultaneously. Since the number of paths for information gathering is much less than that of nodes, the length of the spreading code used in the POCA-CDMA-MAC protocol is shorter greatly than that used in the CDMA-based protocols with transmitter-oriented code assignment (TOCA) or receiver-oriented code assignment (ROCA). Simulation results show that the proposed POCA-CDMA-MAC protocol achieves a higher network throughput and a lower end-to-end delay compared to other CDMA-based MAC protocols. PMID:24193100

  8. S-band multiple-access interference study for advanced tracking and data relay satellite systems

    NASA Technical Reports Server (NTRS)

    Peng, Wei-Chung; Yang, Chau-Chin

    1990-01-01

    The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

  9. Diversity reception for advanced multi-satellite networks: A CDMA approach

    NASA Astrophysics Data System (ADS)

    Colzi, E.; Degaudenzi, R.; Elia, C.; Giannetti, F.; Viola, R.

    Diversity reception for Synchronous CDMA (S-CDMA) is introduced and analyzed. A Gaussian co-channel synchronous and asynchronous interference approximation is derived to evaluate the effects on the system bit error rate. Numerical results are provided for a simple mobile communication system where the signals transmitted by two distinct satellites in visibility are coherently combined by a three fingers Rake receiver. A second example showing performance of an integrated ground/satellite single frequency network for digital audio broadcasting is presented. Results show the capacity advantage of utilizing S-CDMA in combination with diversity reception.

  10. Diversity reception for advanced multi-satellite networks: A CDMA approach

    NASA Technical Reports Server (NTRS)

    Colzi, E.; Degaudenzi, R.; Elia, C.; Giannetti, F.; Viola, R.

    1993-01-01

    Diversity reception for Synchronous CDMA (S-CDMA) is introduced and analyzed. A Gaussian co-channel synchronous and asynchronous interference approximation is derived to evaluate the effects on the system bit error rate. Numerical results are provided for a simple mobile communication system where the signals transmitted by two distinct satellites in visibility are coherently combined by a three fingers Rake receiver. A second example showing performance of an integrated ground/satellite single frequency network for digital audio broadcasting is presented. Results show the capacity advantage of utilizing S-CDMA in combination with diversity reception.

  11. MC-CDMA with frequency domain diversity reception for sectored indoor wireless cellular networks

    NASA Astrophysics Data System (ADS)

    Sibanda, Andrew; Dlodlo, Mqhele E.

    2001-07-01

    A Monte Carlo simulation was conducted to assess the performance of Multi-Carrier Code Division Multiple Access (MC-CDMA) in a sectored cell, in an indoor environment. In each sector, terminal schedule packet transmission using slotted p-persistent Inhibit Sense Multiple Access, while the packets themselves are transmitted using MC-CDMA. The simulated bit error rate performance of MC-CDMA with combining strategies maximal ratio combining (MRC) and equal gain combining (EGC) used in the frequency domain are presented. A comparison is made between analytically determined bit error probability for a single user in an additive white Gaussian noise channel using binary phase shift keying (BPSK), and simulated bit error rate for a single user using MC-CDMA with MRC and EGC. The determination of the number of sectors in a cell is also given. MC-CDMA with diversity combining outperforms BPSK in a non-fading AWGN channel. Further, as the user-number increases, EGC performs better than MRC if these combining strategies are used with MC-CDMA. Finally, the results show the basis for determining the number of sectors in a cell. When using slotted p-persistent ISMA, it is envisaged that only a single user will transmit at a time in a sector.

  12. Design of a Virtual Quadrant Receiver for 4-ary Pulse Position Modulation/Optical CDMA (4-ary PPM/O-CDMA)

    SciTech Connect

    Mendez, A J; Gagliardi, R M; Hernandez, V J; Bennett, C V; Lennon, W J

    2006-07-03

    We describe a receiver that performs optical code division multiple access (O-CDMA) decoding followed by pulse position modulation (PPM) symbol detection that behaves like a radar quadrant receiver. Simulations determine the impact of multi-access interference on symbol detection for up to 32 users.

  13. A Novel Scheme of Fast-frequency Hopping Optical CDMA System with No-hit-zone Sequence

    NASA Astrophysics Data System (ADS)

    Ji, Jianhua; liu, Ling; Wang, Ke; Zhang, Zhipeng; Xu, Ming

    2013-09-01

    In traditional fast frequency-hopping OCDMA (FFH-OCDMA) system, beat noise and multiple-access interference are the main performance limitations, and complicated power control must be employed to eliminate the near-far effect. In this paper, a novel scheme of FFH-OCDMA with no-hit-zone sequence is proposed, which is named NHZ FFH-OCDMA. In NHZ FFH-OCDMA, the synchronization among users can be controlled within permissible time delay, and the code cross-correlation for different users equals zero. Therefore, near-far effect can be eliminated. Furthermore, beat noise and multiple-access interference also can be removed. Simulation of eight simultaneous users with dada rate 100 Mbit/s is demonstrated, where the fiber link consists of 50 km single-mode fiber, plus 5 km dispersion compensating fiber. Simulation results show that the near-far problem of NHZ FFH-OCDMA can be eliminated, and complicated power control can be removed. Therefore, this scheme is a good candidate for optical access network.

  14. A WDM/Optical-CDMA (WDM/O-CDMA) Concept for Avionics Integration

    SciTech Connect

    Mendez, A J; Hernandez, V J; Gagliardi, R M; Braun, S W; Bennett, C V; Lennon, W J

    2005-06-02

    We describe a concept where WDM and O-CDMA share a set of discrete wavelengths and components while using similar modulation formats. O-CDMA acts as a channel multiplier. Experiments show the feasibility of >2X channel multiplication.

  15. Downlink power control in multi-code CDMA for mobile medicine.

    PubMed

    Lin, Chin-Feng; Chang, Wen-Thong; Lee, Hsin-Wang; Hung, Shih-Ii

    2006-05-01

    In this paper, we propose a downlink power-control mechanism to be applied in a multi-code code division multiple access (CDMA) mobile medicine system. The mobile medicine system can provide (i) measured blood pressure and body temperature, (ii) medical signals measured by the electrocardiogram (ECG) device, (iii) mobile patient's history, (iv) G.729 audio signals, (v) Joint Photographic Experts Group 2000 Medical images and Moving Picture Experts Group 4 charge-coupled device sensor video signals. By utilizing a multi-code CDMA spread spectrum communication system with downlink power-control strategy, it is possible for this system to meet the quality of service requirements of a mobile medicine network. In addition, such a system can maximize the resource utilization. For different messages to be sent, the power is controlled according to the requisite bit error rate (BER). Higher transmission power is given to the media with lower BER requirement. Numerical analysis shows that the ratios of transmission power for voice, video, and data virtual channels is approximately 1:2:13 when the BERs for voice, video, and data are 10(wedge)(- 3), 10(wedge)(- 4), and 10(wedge)(- 7), respectively. This power ratio is similar to the ratio of signal-to-noise plus interference power ratio for voice, video, and data during transmission. For the purpose of verifying the proposed argument, a simulation has been done and the results match the derivation very well.

  16. Computer Security Systems Enable Access.

    ERIC Educational Resources Information Center

    Riggen, Gary

    1989-01-01

    A good security system enables access and protects information from damage or tampering, but the most important aspects of a security system aren't technical. A security procedures manual addresses the human element of computer security. (MLW)

  17. DS-CDMA satellite diversity reception for personal satellite communication: Downlink performance analysis

    NASA Technical Reports Server (NTRS)

    DeGaudenzi, Riccardo; Giannetti, Filippo

    1995-01-01

    The downlink of a satellite-mobile personal communication system employing power-controlled Direct Sequence Code Division Multiple Access (DS-CDMA) and exploiting satellite-diversity is analyzed and its performance compared with a more traditional communication system utilizing single satellite reception. The analytical model developed has been thoroughly validated by means of extensive Monte Carlo computer simulations. It is shown how the capacity gain provided by diversity reception shrinks considerably in the presence of increasing traffic or in the case of light shadowing conditions. Moreover, the quantitative results tend to indicate that to combat system capacity reduction due to intra-system interference, no more than two satellites shall be active over the same region. To achieve higher system capacity, differently from terrestrial cellular systems, Multi-User Detection (MUD) techniques are likely to be required in the mobile user terminal, thus considerably increasing its complexity.

  18. Blind Adaptive Decorrelating RAKE (DRAKE) Downlink Receiver for Space-Time Block Coded Multipath CDMA

    NASA Astrophysics Data System (ADS)

    Jayaweera, Sudharman K.; Poor, H. Vincent

    2003-12-01

    A downlink receiver is proposed for space-time block coded CDMA systems operating in multipath channels. By combining the powerful RAKE receiver concept for a frequency selective channel with space-time decoding, it is shown that the performance of mobile receivers operating in the presence of channel fading can be improved significantly. The proposed receiver consists of a bank of decorrelating filters designed to suppress the multiple access interference embedded in the received signal before the space-time decoding. The new receiver performs the space-time decoding along each resolvable multipath component and then the outputs are diversity combined to obtain the final decision statistic. The proposed receiver relies on a key constraint imposed on the output of each filter in the bank of decorrelating filters in order to maintain the space-time block code structure embedded in the signal. The proposed receiver can easily be adapted blindly, requiring only the desired user's signature sequence, which is also attractive in the context of wireless mobile communications. Simulation results are provided to confirm the effectiveness of the proposed receiver in multipath CDMA systems.

  19. Effects of 1950 MHz W-CDMA-like signal on human spermatozoa.

    PubMed

    Nakatani-Enomoto, Setsu; Okutsu, Miho; Suzuki, Satoshi; Suganuma, Ryota; Groiss, Stefan Jun; Kadowaki, Suguru; Enomoto, Hiroyuki; Fujimori, Keiya; Ugawa, Yoshikazu

    2016-09-01

    There are growing concerns about how electromagnetic waves (EMW) emitted from mobile phones affect human spermatozoa. Several experiments have suggested harmful effects of EMW on human sperm quality, motility, velocity, or the deoxyribonucleic acid (DNA) of spermatozoa. In this study, we analyzed the effects on human spermatozoa (sperm motility and kinetic variables) induced by 1 h of exposure to 1950 MHz Wideband Code Division Multiple Access (W-CDMA)-like EMW with specific absorption rates of either 2.0 or 6.0 W/kg, using a computer-assisted sperm analyzer system. We also measured the percentage of 8-hydroxy-2'-deoxyguanosine (8-OHdG) positive spermatozoa with flow cytometry to evaluate damage to DNA. No significant differences were observed between the EMW exposure and the sham exposure in sperm motility, kinetic variables, or 8-OHdG levels. We conclude that W-CDMA-like exposure for 1 h under temperature-controlled conditions has no detectable effect on normal human spermatozoa. Differences in exposure conditions, humidity, temperature control, baseline sperm characteristics, and age of donors may explain inconsistency of our results with several previous studies. Bioelectromagnetics. 37:373-381, 2016. © 2016 Wiley Periodicals, Inc.

  20. Effects of 1950 MHz W-CDMA-like signal on human spermatozoa.

    PubMed

    Nakatani-Enomoto, Setsu; Okutsu, Miho; Suzuki, Satoshi; Suganuma, Ryota; Groiss, Stefan Jun; Kadowaki, Suguru; Enomoto, Hiroyuki; Fujimori, Keiya; Ugawa, Yoshikazu

    2016-09-01

    There are growing concerns about how electromagnetic waves (EMW) emitted from mobile phones affect human spermatozoa. Several experiments have suggested harmful effects of EMW on human sperm quality, motility, velocity, or the deoxyribonucleic acid (DNA) of spermatozoa. In this study, we analyzed the effects on human spermatozoa (sperm motility and kinetic variables) induced by 1 h of exposure to 1950 MHz Wideband Code Division Multiple Access (W-CDMA)-like EMW with specific absorption rates of either 2.0 or 6.0 W/kg, using a computer-assisted sperm analyzer system. We also measured the percentage of 8-hydroxy-2'-deoxyguanosine (8-OHdG) positive spermatozoa with flow cytometry to evaluate damage to DNA. No significant differences were observed between the EMW exposure and the sham exposure in sperm motility, kinetic variables, or 8-OHdG levels. We conclude that W-CDMA-like exposure for 1 h under temperature-controlled conditions has no detectable effect on normal human spermatozoa. Differences in exposure conditions, humidity, temperature control, baseline sperm characteristics, and age of donors may explain inconsistency of our results with several previous studies. Bioelectromagnetics. 37:373-381, 2016. © 2016 Wiley Periodicals, Inc. PMID:27288295

  1. Computer access security code system

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr. (Inventor)

    1990-01-01

    A security code system for controlling access to computer and computer-controlled entry situations comprises a plurality of subsets of alpha-numeric characters disposed in random order in matrices of at least two dimensions forming theoretical rectangles, cubes, etc., such that when access is desired, at least one pair of previously unused character subsets not found in the same row or column of the matrix is chosen at random and transmitted by the computer. The proper response to gain access is transmittal of subsets which complete the rectangle, and/or a parallelepiped whose opposite corners were defined by first groups of code. Once used, subsets are not used again to absolutely defeat unauthorized access by eavesdropping, and the like.

  2. Application of neural networks to channel assignment for cellular CDMA networks with multiple services and mobile base stations

    NASA Astrophysics Data System (ADS)

    Hortos, William S.

    1996-03-01

    The use of artificial neural networks to the channel assignment problem for cellular code- division multiple access (CDMA) telecommunications systems is considered. CDMA takes advantage of voice activity and spatial isolation because its capacity is only interference limited, unlike time-division multiple access (TDMA) and frequency-division multiple access (FDMA) where capacities are bandwidth limited. Any reduction in interference in CDMA translates linearly into increased capacity. FDMA and TDMA use a frequency reuse pattern as a method to increase capacity, while CDMA reuses the same frequency for all cells and gains a reuse efficiency by means of orthogonal codes. The latter method can improve system capacity by factors of four to six over digital TDMA or FDMA. Cellular carriers are planning to provide multiple communication services using CDMA in the next generation cellular system infrastructure. The approach of this study is the use of neural network methods for automatic and local network control, based on traffic behavior in specific cell cites and demand history. The goal is to address certain problems associated with the management of mobile and personal communication services in a cellular radio communications environment. In planning a cellular radio network, the operator assigns channels to the radio cells so that the probability of the processed carrier-to-interference ratio, CII, exceeding a predefined value is sufficiently low. The RF propagation, determined from the topography and infrastructure in the operating area, is used in conjunction with the densities of expected communications traffic to formulate interference constraints. These constraints state which radio cells may use the same code (channel) or adjacent channels at a time. The traffic loading and the number of service grades can also be used to calculate the number of required channels (codes) for each cell. The general assignment problem is the task of assigning the required number

  3. Automated Computer Access Request System

    NASA Technical Reports Server (NTRS)

    Snook, Bryan E.

    2010-01-01

    The Automated Computer Access Request (AutoCAR) system is a Web-based account provisioning application that replaces the time-consuming paper-based computer-access request process at Johnson Space Center (JSC). Auto- CAR combines rules-based and role-based functionality in one application to provide a centralized system that is easily and widely accessible. The system features a work-flow engine that facilitates request routing, a user registration directory containing contact information and user metadata, an access request submission and tracking process, and a system administrator account management component. This provides full, end-to-end disposition approval chain accountability from the moment a request is submitted. By blending both rules-based and rolebased functionality, AutoCAR has the flexibility to route requests based on a user s nationality, JSC affiliation status, and other export-control requirements, while ensuring a user s request is addressed by either a primary or backup approver. All user accounts that are tracked in AutoCAR are recorded and mapped to the native operating system schema on the target platform where user accounts reside. This allows for future extensibility for supporting creation, deletion, and account management directly on the target platforms by way of AutoCAR. The system s directory-based lookup and day-today change analysis of directory information determines personnel moves, deletions, and additions, and automatically notifies a user via e-mail to revalidate his/her account access as a result of such changes. AutoCAR is a Microsoft classic active server page (ASP) application hosted on a Microsoft Internet Information Server (IIS).

  4. LANSCE personnel access control system

    SciTech Connect

    Sturrock, J.C.; Gallegos, F.R.; Hall, M.J.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. The Personnel Access Control System (PACS) is a component of the RSS that is designed to prevent personnel access to areas where prompt radiation is a hazard. PACS was designed to replace several older personnel safety systems (PSS) with a single modem unified design. Lessons learned from the operation over the last 20 years were incorporated into a redundant sensor, single-point failure safe, fault tolerant, and tamper-resistant system that prevents access to the beam areas by controlling the access keys and beam stoppers. PACS uses a layered philosophy to the physical and electronic design. The most critical assemblies are battery backed up, relay logic circuits; less critical devices use Programmable Logic Controllers (PLCs) for timing functions and communications. Outside reviewers have reviewed the operational safety of the design. The design philosophy, lessons learned, hardware design, software design, operation, and limitations of the device are described.

  5. Remotely Accessible Management System (RAMS).

    ERIC Educational Resources Information Center

    Wood, Rex

    Oakland Schools, an Intermediate School District for Administration, operates a Remotely Accessible Management System (RAMS). RAMS is composed of over 100 computer programs, each of which performs procedures on the files of the 28 local school districts comprising the constituency of Oakland Schools. This regional service agency covers 900 square…

  6. Impact of ultrawideband on CDMA2000 forward link performance

    NASA Astrophysics Data System (ADS)

    Green, Marilynn P.; Wang, Peter

    2004-04-01

    The future proliferation of UWB-enabled devices raises legitimate concerns for the impact of its use on the performance of incumbent radio systems. In this paper, we present analytical models that quantify the blocking probability and the increase in forward traffic channel power allocation in the presence of noise-like UWB interference. The cdma2000 forward link has a fixed maximum transmit power but can control the fraction of total forward link power allocated to each traffic channel. If a terminal experiences a loss in sensitivity due to the presence of UWB energy, the base station can raise its power allocation to compensate for these conditions, up to a limit. If, however, the conditions at the handset require more power than that which is allowed by the system, then the traffic channel is blocked. In this study, we consider system performance as a function of the UWB power spectral density and its separation from the victim cdma2000 1X terminal. Although further study is pending, our analysis generally shows that protection of the cdma2000 forward link for indoor reception requires the UWB indoor emission limit to at least be below 20 dB below the currently specified emission limit when there is a single radiating UWB source.

  7. Fast Access Data Acquisition System

    SciTech Connect

    Dr. Vladimir Katsman

    1998-03-17

    Our goal in this program is to develop Fast Access Data Acquisition System (FADAS) by combining the flexibility of Multilink's GaAs and InP electronics and electro-optics with an extremely high data rate for the efficient handling and transfer of collider experimental data. This novel solution is based on Multilink's and Los Alamos National Laboratory's (LANL) unique components and technologies for extremely fast data transfer, storage, and processing.

  8. Direct sequence spread spectrum CDMA in shared spectrum applications

    NASA Technical Reports Server (NTRS)

    Schilling, Donald L.; Milstein, Laurence B.; Pickholtz, Raymond L.; Miller, Frank

    1991-01-01

    Personal Communication Network (PCN) is an entirely wireless communication system with the capability of assessing the wired telephone system to reach anyone processing only a wired telephone. It is expected to compete with the existing mobile cellular system which connects directly to the wired telephone system. While many PCN systems employ TDMA technology, the PCN system described here uses Broadband CDMA (BCDMA(sup SM)) which is capable of sharing the spectrum with other users and which is extremely resistant to fading caused by multipath.

  9. Data Access System for Hydrology

    NASA Astrophysics Data System (ADS)

    Whitenack, T.; Zaslavsky, I.; Valentine, D.; Djokic, D.

    2007-12-01

    As part of the CUAHSI HIS (Consortium of Universities for the Advancement of Hydrologic Science, Inc., Hydrologic Information System), the CUAHSI HIS team has developed Data Access System for Hydrology or DASH. DASH is based on commercial off the shelf technology, which has been developed in conjunction with a commercial partner, ESRI. DASH is a web-based user interface, developed in ASP.NET developed using ESRI ArcGIS Server 9.2 that represents a mapping, querying and data retrieval interface over observation and GIS databases, and web services. This is the front end application for the CUAHSI Hydrologic Information System Server. The HIS Server is a software stack that organizes observation databases, geographic data layers, data importing and management tools, and online user interfaces such as the DASH application, into a flexible multi- tier application for serving both national-level and locally-maintained observation data. The user interface of the DASH web application allows online users to query observation networks by location and attributes, selecting stations in a user-specified area where a particular variable was measured during a given time interval. Once one or more stations and variables are selected, the user can retrieve and download the observation data for further off-line analysis. The DASH application is highly configurable. The mapping interface can be configured to display map services from multiple sources in multiple formats, including ArcGIS Server, ArcIMS, and WMS. The observation network data is configured in an XML file where you specify the network's web service location and its corresponding map layer. Upon initial deployment, two national level observation networks (USGS NWIS daily values and USGS NWIS Instantaneous values) are already pre-configured. There is also an optional login page which can be used to restrict access as well as providing a alternative to immediate downloads. For large request, users would be notified via

  10. Hypersensitivity to RF fields emitted from CDMA cellular phones: a provocation study.

    PubMed

    Nam, Ki Chang; Lee, Ju Hyung; Noh, Hyung Wook; Cha, Eun Jong; Kim, Nam Hyun; Kim, Deok Won

    2009-12-01

    With the number of cellular phone users rapidly increasing, there is a considerable amount of public concern regarding the effects that electromagnetic fields (EMFs) from cellular phones have on health. People with self-attributed electromagnetic hypersensitivity (EHS) complain of subjective symptoms such as headaches, insomnia, and memory loss, and attribute these symptoms to radio frequency (RF) radiation from cellular phones and/or base stations. However, EHS is difficult to diagnose because it relies on a person's subjective judgment. Various provocation studies have been conducted on EHS caused by Global System for Mobile Communications (GSM) phones in which heart rate and blood pressure or subjective symptoms were investigated. However, there have been few sham-controlled provocation studies on EHS with Code Division Multiple Access (CDMA) phones where physiological parameters, subjective symptoms, and perception of RF radiation for EHS and non-EHS groups were simultaneously investigated. In this study, two volunteer groups of 18 self-reported EHS and 19 non-EHS persons were tested for both sham and real RF exposure from CDMA cellular phones with a 300 mW maximum exposure that lasted half an hour. We investigated not only the physiological parameters such as heart rate, respiration rate, and heart rate variability (HRV), but also various subjective symptoms and the perception of EMF. In conclusion, RF exposure did not have any effects on physiological parameters or subjective symptoms in either group. As for EMF perception, there was no evidence that the EHS group better perceived EMF than the non-EHS group.

  11. Common Badging and Access Control System (CBACS)

    NASA Technical Reports Server (NTRS)

    Dischinger, Portia

    2005-01-01

    This slide presentation presents NASA's Common Badging and Access Control System. NASA began a Smart Card implementation in January 2004. Following site surveys, it was determined that NASA's badging and access control systems required upgrades to common infrastructure in order to provide flexibly, usability, and return on investment prior to a smart card implantation. Common Badging and Access Control System (CBACS) provides the common infrastructure from which FIPS-201 compliant processes, systems, and credentials can be developed and used.

  12. Distributed Access to Administrative Systems.

    ERIC Educational Resources Information Center

    Carson, Eugene

    1987-01-01

    Administrators, faculty, and staff should have electronic access to records needed to perform their jobs, and students should have access to their own records--course registration and addresses. User-directed analysis and reporting are discussed and the security and audit issues are examined. (Author/MLW)

  13. ACCESS Sub-system Performance

    NASA Astrophysics Data System (ADS)

    Kaiser, Mary Elizabeth; Morris, Matthew J.; Aldoroty, Lauren Nicole; Godon, David; Pelton, Russell; McCandliss, Stephan R.; Kurucz, Robert L.; Kruk, Jeffrey W.; Rauscher, Bernard J.; Kimble, Randy A.; Wright, Edward L.; Benford, Dominic J.; Gardner, Jonathan P.; Feldman, Paul D.; Moos, H. Warren; Riess, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, William Van Dyke; Sahnow, David J.; Lampton, Michael; Perlmutter, Saul

    2016-01-01

    ACCESS: Absolute Color Calibration Experiment for Standard Stars is a series of rocket-borne sub-orbital missions and ground-based experiments designed to leverage significant technological advances in detectors, instruments, and the precision of the fundamental laboratory standards used to calibrate these instruments to enable improvements in the precision of the astrophysical flux scale through the transfer of laboratory absolute detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass.A cross wavelength calibration of the astrophysical flux scale to this level of precision over this broad a bandpass is relevant for the data used to probe fundamental astrophysical problems such as the SNeIa photometry based measurements used to constrain dark energy theories.We will describe the strategy for achieving this level of precision, the payload and calibration configuration, present sub-system test data, and the status and preliminary performance of the integration and test of the spectrograph and telescope. NASA APRA sounding rocket grant NNX14AH48G supports this work.

  14. Easy Access: Auditing the System Network

    ERIC Educational Resources Information Center

    Wiech, Dean

    2013-01-01

    In today's electronic learning environment, access to appropriate systems and data is of the utmost importance to students, faculty, and staff. Without proper access to the school's internal systems, teachers could be prevented from logging on to an online learning system and students might be unable to submit course work to an online…

  15. All-optical code routing in interconnected optical CDMA and WDM ring networks.

    PubMed

    Deng, Yanhua; Fok, Mable P; Prucnal, Paul R; Wang, Ting

    2010-11-01

    We propose an all-optical hybrid network composed of optical code division multiple access (CDMA) rings interconnecting through a reconfigurable wavelength division multiplexing (WDM) metro area ring. This network retains the advantages of both the optical CDMA and WDM techniques, including asynchronous access and differentiated quality of service, while removing the hard limit on the number of subscribers and increasing network flexibility. The all-optical network is enabled by using nonlinear optical loop mirrors in an add/drop router (ADR) that performs code conversion, dropping, and switching asynchronously. We experimentally demonstrate the functionalities of the ADR in the proposed scheme asynchronously and obtain error-free performance. The bit-error rate measurements show acceptable power penalties for different code routes.

  16. A Wideband Satcom Based Avionics Network with CDMA Uplink and TDM Downlink

    NASA Technical Reports Server (NTRS)

    Agrawal, D.; Johnson, B. S.; Madhow, U.; Ramchandran, K.; Chun, K. S.

    2000-01-01

    The purpose of this paper is to describe some key technical ideas behind our vision of a future satcom based digital communication network for avionics applications The key features of our design are as follows: (a) Packetized transmission to permit efficient use of system resources for multimedia traffic; (b) A time division multiplexed (TDM) satellite downlink whose physical layer is designed to operate the satellite link at maximum power efficiency. We show how powerful turbo codes (invented originally for linear modulation) can be used with nonlinear constant envelope modulation, thus permitting the satellite amplifier to operate in a power efficient nonlinear regime; (c) A code division multiple access (CDMA) satellite uplink, which permits efficient access to the satellite from multiple asynchronous users. Closed loop power control is difficult for bursty packetized traffic, especially given the large round trip delay to the satellite. We show how adaptive interference suppression techniques can be used to deal with the ensuing near-far problem; (d) Joint source-channel coding techniques are required both at the physical and the data transport layer to optimize the end-to-end performance. We describe a novel approach to multiple description image encoding at the data transport layer in this paper.

  17. A Space-Time Signal Decomposition Algorithm for Downlink MIMO DS-CDMA Receivers

    NASA Astrophysics Data System (ADS)

    Wang, Yung-Yi; Fang, Wen-Hsien; Chen, Jiunn-Tsair

    We propose a dimension reduction algorithm for the receiver of the downlink of direct-sequence code-division multiple access (DS-CDMA) systems in which both the transmitters and the receivers employ antenna arrays of multiple elements. To estimate the high order channel parameters, we develop a layered architecture using dimension-reduced parameter estimation algorithms to estimate the frequency-selective multipath channels. In the proposed architecture, to exploit the space-time geometric characteristics of multipath channels, spatial beamformers and constrained (or unconstrained) temporal filters are adopted for clustered-multipath grouping and path isolation. In conjunction with the multiple access interference (MAI) suppression techniques, the proposed architecture jointly estimates the direction of arrivals, propagation delays, and fading amplitudes of the downlink fading multipaths. With the outputs of the proposed architecture, the signals of interest can then be naturally detected by using path-wise maximum ratio combining. Compared to the traditional techniques, such as the Joint-Angle-and-Delay-Estimation (JADE) algorithm for DOA-delay joint estimation and the space-time minimum mean square error (ST-MMSE) algorithm for signal detection, computer simulations show that the proposed algorithm substantially mitigate the computational complexity at the expense of only slight performance degradation.

  18. The effects of simultaneous combined exposure to CDMA and WCDMA electromagnetic fields on rat testicular function.

    PubMed

    Lee, Hae-June; Jin, Yeung Bae; Kim, Tae-Hong; Pack, Jeong-Ki; Kim, Nam; Choi, Hyung-Do; Lee, Jae-Seon; Lee, Yun-Sil

    2012-05-01

    Wireless mobile phones and other telecommunication devices are used extensively in daily life. We therefore examined the effects of combined exposure to radiofrequency electromagnetic fields (RF-EMF) on rat testicular function, specifically with respect to sensitive processes such as spermatogenesis. Male rats were exposed to single code division multiple access (CDMA) and wideband code division multiple access (WCDMA) RF signals for 12 weeks. The RF exposure schedule comprised 45 min/day, 5 days/week for a total of 12 weeks. The whole-body average specific absorption rate (SAR) of CDMA and WCDMA was 2.0 W/kg each or 4.0 W/kg in total. We then investigated the correlates of testicular function such as sperm count in the cauda epididymis, testosterone concentration in the blood serum, malondialdehyde concentrations in the testes and epididymis, frequency of spermatogenesis stages, and appearance of apoptotic cells in the testes. We also immunoblotted for p53, bcl2, GADD45, cyclin G, and HSP70 in the testes of sham- and combined RF-exposed animals. Based on the results, we concluded that simultaneous exposure to CDMA and WCDMA RF-EMFs at 4.0 W/kg SAR did not have any observable adverse effects on rat spermatogenesis.

  19. Components of the airport access system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The organizations and agencies which make up or influence the airport access system are examined. These include the airport, the airline industry, the public and private transit agencies which provide ground access to the airport, and the regulatory agencies which affect all of these organizations and their actions. Each component, with the exception of the regulatory agencies is described in terms of its legal status, its sources of funds, and the nature of its relationship with the other components. Conclusions regarding the system components' effects on airport access and recommendations for changes which appear practical are presented.

  20. Performance Analysis of Direct-Sequence Code-Division Multiple-Access Communications with Asymmetric Quadrature Phase-Shift-Keying Modulation

    NASA Technical Reports Server (NTRS)

    Wang, C.-W.; Stark, W.

    2005-01-01

    This article considers a quaternary direct-sequence code-division multiple-access (DS-CDMA) communication system with asymmetric quadrature phase-shift-keying (AQPSK) modulation for unequal error protection (UEP) capability. Both time synchronous and asynchronous cases are investigated. An expression for the probability distribution of the multiple-access interference is derived. The exact bit-error performance and the approximate performance using a Gaussian approximation and random signature sequences are evaluated by extending the techniques used for uniform quadrature phase-shift-keying (QPSK) and binary phase-shift-keying (BPSK) DS-CDMA systems. Finally, a general system model with unequal user power and the near-far problem is considered and analyzed. The results show that, for a system with UEP capability, the less protected data bits are more sensitive to the near-far effect that occurs in a multiple-access environment than are the more protected bits.

  1. Peak power minimization in indoor CDMA communications using clusters of antennas

    NASA Astrophysics Data System (ADS)

    Abolhassani, Bahman

    "Battery life" and "cost" constraints are presenting new challenges for the design of wireless networks. The major focus of past research on transmit power control, diversity, modulation and coding techniques has been limited to maximizing coverage and/or capacity for cellular telephone systems. However, for battery powered wireless handsets connected through indoor wireless links, the optimization objective is shifting from link efficiency to battery efficiency and cost. In this thesis, the battery life of handsets and the cost of network are both addressed for an indoor code division multiple access (CDMA) communications system using time division duplex (TDD). A wireless handset needs a large dynamic range transmitter amplifier in order to overcome channel path loss and fading. This makes the amplifier inefficient such that its power consumption becomes proportional to the peak transmit power. Therefore, the amplifier needs a large, heavy and expensive battery which lasts for only a few hours. Indoor wireless users, however, need small, light, low cost handsets with batteries that last for days rather than for a few hours. To achieve a long battery life for handsets, a system architecture is proposed in which each cell uses a central base station along with several radioports. The radioports placed at optimal or near-optimal locations in order to minimize the maximum path loss experienced by handsets. Each radioport may use more than one antenna to combat Rayleigh fading. The central base station selects the radioport that provides the strongest maximally ratio combined signal. An infra-structure cost model is developed for the proposed system, which depends on the peak transmit power capability of handsets and of other system parameters and performances. The number of parameters affecting the network infra-structure cost is high, which makes the cost minimization problematic. To avoid large computation time, a new network planning approach is proposed: its

  2. CDMA and TDMA based neural nets.

    PubMed

    Herrero, J C

    2001-06-01

    CDMA and TDMA telecommunication techniques were established long time ago, but they have acquired a renewed presence due to the rapidly increasing mobile phones demand. In this paper, we are going to see they are suitable for neural nets, if we leave the concept "connection" between processing units and we adopt the concept "messages" exchanged between them. This may open the door to neural nets with a higher number of processing units and flexible configuration.

  3. Access Control Management for SCADA Systems

    NASA Astrophysics Data System (ADS)

    Hong, Seng-Phil; Ahn, Gail-Joon; Xu, Wenjuan

    The information technology revolution has transformed all aspects of our society including critical infrastructures and led a significant shift from their old and disparate business models based on proprietary and legacy environments to more open and consolidated ones. Supervisory Control and Data Acquisition (SCADA) systems have been widely used not only for industrial processes but also for some experimental facilities. Due to the nature of open environments, managing SCADA systems should meet various security requirements since system administrators need to deal with a large number of entities and functions involved in critical infrastructures. In this paper, we identify necessary access control requirements in SCADA systems and articulate access control policies for the simulated SCADA systems. We also attempt to analyze and realize those requirements and policies in the context of role-based access control that is suitable for simplifying administrative tasks in large scale enterprises.

  4. Distributed Access View Integrated Database (DAVID) system

    NASA Technical Reports Server (NTRS)

    Jacobs, Barry E.

    1991-01-01

    The Distributed Access View Integrated Database (DAVID) System, which was adopted by the Astrophysics Division for their Astrophysics Data System, is a solution to the system heterogeneity problem. The heterogeneous components of the Astrophysics problem is outlined. The Library and Library Consortium levels of the DAVID approach are described. The 'books' and 'kits' level is discussed. The Universal Object Typer Management System level is described. The relation of the DAVID project with the Small Business Innovative Research (SBIR) program is explained.

  5. Multiuser receiver for DS-CDMA signals in multipath channels: an enhanced multisurface method.

    PubMed

    Mahendra, Chetan; Puthusserypady, Sadasivan

    2006-11-01

    This paper deals with the problem of multiuser detection in direct-sequence code-division multiple-access (DS-CDMA) systems in multipath environments. The existing multiuser detectors can be divided into two categories: (1) low-complexity poor-performance linear detectors and (2) high-complexity good-performance nonlinear detectors. In particular, in channels where the orthogonality of the code sequences is destroyed by multipath, detectors with linear complexity perform much worse than the nonlinear detectors. In this paper, we propose an enhanced multisurface method (EMSM) for multiuser detection in multipath channels. EMSM is an intermediate piecewise linear detection scheme with a run-time complexity linear in the number of users. Its bit error rate performance is compared with existing linear detectors, a nonlinear radial basis function detector trained by the new support vector learning algorithm, and Verdu's optimal detector. Simulations in multipath channels, for both synchronous and asynchronous cases, indicate that it always outperforms all other linear detectors, performing nearly as well as nonlinear detectors.

  6. A voice password system for access security

    SciTech Connect

    Birnbaum, M.; Cohen, L.A.; Welsh, F.X.

    1986-09-01

    A voice password system for access security using speaker verification technology has been designed for use over dial-up telephone lines. The voice password system (VPS) can provide secure access to telephone networks, computers, rooms, and buildings. It also has application in office automation systems, electric funds transfer, and ''smart cards'' (interactive computers embedded in credit-card-sized packages). As increasing attention is focused on access security in the public, private, and government sectors, the voice password system can provide a timely solution to the security dilemma. The VPS uses modes of communication available to almost everyone (the human voice and the telephone). A user calls the VPS, enters his or her identification number (ID) by touch-tone telephone, and then speaks a password. This is usually a phrase or a sentence of about seven syllables. On initial calls, the VPS creates a model of the user's voice, called a reference template, and labels it with the caller's unique user ID. To gain access later, the user calls the system, enters the proper user ID, and speaks the password phrase. The VPS compares the user's stored reference template with the spoken password and produces a distance score.

  7. Preservation Film: Platform for Digital Access Systems.

    ERIC Educational Resources Information Center

    Jones, C. Lee

    Preservation efforts for an increasingly digitally oriented future have turned to advanced and improved methods of preservation on microfilm, which has a life expectancy of more than 500 years when properly prepared, stored, and managed, and can support a wide range of digital access systems. Computer controlled cameras can provide significantly…

  8. Cardea: Dynamic Access Control in Distributed Systems

    NASA Technical Reports Server (NTRS)

    Lepro, Rebekah

    2004-01-01

    Modern authorization systems span domains of administration, rely on many different authentication sources, and manage complex attributes as part of the authorization process. This . paper presents Cardea, a distributed system that facilitates dynamic access control, as a valuable piece of an inter-operable authorization framework. First, the authorization model employed in Cardea and its functionality goals are examined. Next, critical features of the system architecture and its handling of the authorization process are then examined. Then the S A M L and XACML standards, as incorporated into the system, are analyzed. Finally, the future directions of this project are outlined and connection points with general components of an authorization system are highlighted.

  9. Performance of asynchronous fiber-optic code division multiple access system based on three-dimensional wavelength/time/space codes and its link analysis.

    PubMed

    Singh, Jaswinder

    2010-03-10

    A novel family of three-dimensional (3-D) wavelength/time/space codes for asynchronous optical code-division-multiple-access (CDMA) systems with "zero" off-peak autocorrelation and "unity" cross correlation is reported. Antipodal signaling and differential detection is employed in the system. A maximum of [(W x T+1) x W] codes are generated for unity cross correlation, where W and T are the number of wavelengths and time chips used in the code and are prime. The conditions for violation of the cross-correlation constraint are discussed. The expressions for number of generated codes are determined for various code dimensions. It is found that the maximum number of codes are generated for S < or = min(W,T), where W and T are prime and S is the number of space channels. The performance of these codes is compared to the earlier reported two-dimensional (2-D)/3-D codes for asynchronous systems. The codes have a code-set-size to code-size ratio greater than W/S. For instance, with a code size of 2065 (59 x 7 x 5), a total of 12,213 users can be supported, and 130 simultaneous users at a bit-error rate (BER) of 10(-9). An arrayed-waveguide-grating-based reconfigurable encoder/decoder design for 2-D implementation for the 3-D codes is presented so that the need for multiple star couplers and fiber ribbons is eliminated. The hardware requirements of the coders used for various modulation/detection schemes are given. The effect of insertion loss in the coders is shown to be significantly reduced with loss compensation by using an amplifier after encoding. An optical CDMA system for four users is simulated and the results presented show the improvement in performance with the use of loss compensation.

  10. Support vector machine multiuser receiver for DS-CDMA signals in multipath channels.

    PubMed

    Chen, S; Samingan, A K; Hanzo, L

    2001-01-01

    The problem of constructing an adaptive multiuser detector (MUD) is considered for direct sequence code division multiple access (DS-CDMA) signals transmitted through multipath channels. The emerging learning technique, called support vector machines (SVM), is proposed as a method of obtaining a nonlinear MUD from a relatively small training data block. Computer simulation is used to study this SVM MUD, and the results show that it can closely match the performance of the optimal Bayesian one-shot detector. Comparisons with an adaptive radial basis function (RBF) MUD trained by an unsupervised clustering algorithm are discussed.

  11. Obstacle Characterization in a Geocrowdsourced Accessibility System

    NASA Astrophysics Data System (ADS)

    Qin, H.; Aburizaiza, A. O.; Rice, R. M.; Paez, F.; Rice, M. T.

    2015-08-01

    Transitory obstacles - random, short-lived and unpredictable objects - are difficult to capture in any traditional mapping system, yet they have significant negative impacts on the accessibility of mobility- and visually-impaired individuals. These transitory obstacles include sidewalk obstructions, construction detours, and poor surface conditions. To identify these obstacles and assist the navigation of mobility- and visually- impaired individuals, crowdsourced mapping applications have been developed to harvest and analyze the volunteered obstacles reports from local students, faculty, staff, and residents. In this paper, we introduce a training program designed and implemented for recruiting and motivating contributors to participate in our geocrowdsourced accessibility system, and explore the quality of geocrowdsourced data with a comparative analysis methodology.

  12. Common Badging and Access Control System (CBACS)

    NASA Technical Reports Server (NTRS)

    Baldridge, Tim

    2005-01-01

    The goals of the project are: Achieve high business value through a common badging and access control system that integrates with smart cards. Provide physical (versus logical) deployment of smart cards initially. Provides a common consistent and reliable environment into which to release the smart card. Gives opportunity to develop agency-wide consistent processes, practices and policies. Enables enterprise data capture and management. Promotes data validation prior to SC issuance.

  13. Performance of random multiple access transmission system

    NASA Technical Reports Server (NTRS)

    Phinainitisart, N.; Wu, W. W.

    1990-01-01

    The performance of the Random Multiple Access (RMA) technique, applied to a direct terminal-to-terminal link with a large number of potential users, is determined. The average signal-to-noise ratio (SNR) is derived. Under Gaussian assumption, the approximation of the probability of error is given. The analysis shows that the system performance is affected by the sequence length, the number of simultaneous users, and the number of cochannel symbols, but is not sensitive to the thermal noise. The performance of using very small aperture antenna for both transmitting and receiving without a hub station is given.

  14. Science information systems: Archive, access, and retrieval

    NASA Technical Reports Server (NTRS)

    Campbell, William J.

    1991-01-01

    The objective of this research is to develop technology for the automated characterization and interactive retrieval and visualization of very large, complex scientific data sets. Technologies will be developed for the following specific areas: (1) rapidly archiving data sets; (2) automatically characterizing and labeling data in near real-time; (3) providing users with the ability to browse contents of databases efficiently and effectively; (4) providing users with the ability to access and retrieve system independent data sets electronically; and (5) automatically alerting scientists to anomalies detected in data.

  15. Decentralized energy systems for clean electricity access

    NASA Astrophysics Data System (ADS)

    Alstone, Peter; Gershenson, Dimitry; Kammen, Daniel M.

    2015-04-01

    Innovative approaches are needed to address the needs of the 1.3 billion people lacking electricity, while simultaneously transitioning to a decarbonized energy system. With particular focus on the energy needs of the underserved, we present an analytic and conceptual framework that clarifies the heterogeneous continuum of centralized on-grid electricity, autonomous mini- or community grids, and distributed, individual energy services. A historical analysis shows that the present day is a unique moment in the history of electrification where decentralized energy networks are rapidly spreading, based on super-efficient end-use appliances and low-cost photovoltaics. We document how this evolution is supported by critical and widely available information technologies, particularly mobile phones and virtual financial services. These disruptive technology systems can rapidly increase access to basic electricity services and directly inform the emerging Sustainable Development Goals for quality of life, while simultaneously driving action towards low-carbon, Earth-sustaining, inclusive energy systems.

  16. Dynamic quality of service differentiation using fixed code weight in optical CDMA networks

    NASA Astrophysics Data System (ADS)

    Kakaee, Majid H.; Essa, Shawnim I.; Abd, Thanaa H.; Seyedzadeh, Saleh

    2015-11-01

    The emergence of network-driven applications, such as internet, video conferencing, and online gaming, brings in the need for a network the environments with capability of providing diverse Quality of Services (QoS). In this paper, a new code family of novel spreading sequences, called a Multi-Service (MS) code, has been constructed to support multiple services in Optical- Code Division Multiple Access (CDMA) system. The proposed method uses fixed weight for all services, however reducing the interfering codewords for the users requiring higher QoS. The performance of the proposed code is demonstrated using mathematical analysis. It shown that the total number of served users with satisfactory BER of 10-9 using NB=2 is 82, while they are only 36 and 10 when NB=3 and 4 respectively. The developed MS code is compared with variable-weight codes such as Variable Weight-Khazani Syed (VW-KS) and Multi-Weight-Random Diagonal (MW-RD). Different numbers of basic users (NB) are used to support triple-play services (audio, data and video) with different QoS requirements. Furthermore, reference to the BER of 10-12, 10-9, and 10-3 for video, data and audio, respectively, the system can support up to 45 total users. Hence, results show that the technique can clearly provide a relative QoS differentiation with lower value of basic users can support larger number of subscribers as well as better performance in terms of acceptable BER of 10-9 at fixed code weight.

  17. Multi-access laser communications transceiver system

    NASA Technical Reports Server (NTRS)

    Ross, Monte (Inventor); Lokerson, Donald C. (Inventor); Fitzmaurice, Michael W. (Inventor); Meyer, Daniel D. (Inventor)

    1993-01-01

    A satellite system for optical communications such as a multi-access laser transceiver system. Up to six low Earth orbiting satellites send satellite data to a geosynchronous satellite. The data is relayed to a ground station at the Earth's surface. The earth pointing geosynchronous satellite terminal has no gimbal but has a separate tracking mechanism for tracking each low Earth orbiting satellite. The tracking mechanism has a ring assembly rotatable about an axis coaxial with the axis of the field of view of the geosynchronous satellite and a pivotable arm mounted for pivotal movement on the ring assembly. An optical pickup mechanism at the end of each arm is positioned for optical communication with one of the orbiting satellites by rotation of the ring.

  18. Replica Analysis of Multiuser Detection for Code Division Multiple Access with M-Ary Phase-Shift Keying

    NASA Astrophysics Data System (ADS)

    Kato, Hiroyuki; Okada, Masato; Miyoshi, Seiji

    2013-07-01

    We analyze the performance of the maximizer of the posterior marginals (MPM) detector for code division multiple access (CDMA) multiuser detection with M-ary phase shift keying (M-ary PSK) in the large system limit by the replica method. The obtained theory agrees with computer simulation reasonably well. We also derive the theory in the case of the large M limit and discuss the dependence of the properties of M-ary PSK CDMA communication on M. We show that the waterfall phenomenon occurs for both the finite and infinite values of M. We also show that a value of M for which the decoded phase information on the original user symbol becomes minimum exists. Furthermore, we discuss the relationship between the theory based on the replica method and that based on self-consistent signal-to-noise analysis (SCSNA).

  19. Digital Autonomous Terminal Access Communication (DATAC) system

    NASA Technical Reports Server (NTRS)

    Novacki, Stanley M., III

    1987-01-01

    In order to accommodate the increasing number of computerized subsystems aboard today's more fuel efficient aircraft, the Boeing Co. has developed the DATAC (Digital Autonomous Terminal Access Control) bus to minimize the need for point-to-point wiring to interconnect these various systems, thereby reducing total aircraft weight and maintaining an economical flight configuration. The DATAC bus is essentially a local area network providing interconnections for any of the flight management and control systems aboard the aircraft. The task of developing a Bus Monitor Unit was broken down into four subtasks: (1) providing a hardware interface between the DATAC bus and the Z8000-based microcomputer system to be used as the bus monitor; (2) establishing a communication link between the Z8000 system and a CP/M-based computer system; (3) generation of data reduction and display software to output data to the console device; and (4) development of a DATAC Terminal Simulator to facilitate testing of the hardware and software which transfer data between the DATAC's bus and the operator's console in a near real time environment. These tasks are briefly discussed.

  20. Adaptive Code Division Multiple Access Protocol for Wireless Network-on-Chip Architectures

    NASA Astrophysics Data System (ADS)

    Vijayakumaran, Vineeth

    Massive levels of integration following Moore's Law ushered in a paradigm shift in the way on-chip interconnections were designed. With higher and higher number of cores on the same die traditional bus based interconnections are no longer a scalable communication infrastructure. On-chip networks were proposed enabled a scalable plug-and-play mechanism for interconnecting hundreds of cores on the same chip. Wired interconnects between the cores in a traditional Network-on-Chip (NoC) system, becomes a bottleneck with increase in the number of cores thereby increasing the latency and energy to transmit signals over them. Hence, there has been many alternative emerging interconnect technologies proposed, namely, 3D, photonic and multi-band RF interconnects. Although they provide better connectivity, higher speed and higher bandwidth compared to wired interconnects; they also face challenges with heat dissipation and manufacturing difficulties. On-chip wireless interconnects is one other alternative proposed which doesn't need physical interconnection layout as data travels over the wireless medium. They are integrated into a hybrid NOC architecture consisting of both wired and wireless links, which provides higher bandwidth, lower latency, lesser area overhead and reduced energy dissipation in communication. However, as the bandwidth of the wireless channels is limited, an efficient media access control (MAC) scheme is required to enhance the utilization of the available bandwidth. This thesis proposes using a multiple access mechanism such as Code Division Multiple Access (CDMA) to enable multiple transmitter-receiver pairs to send data over the wireless channel simultaneously. It will be shown that such a hybrid wireless NoC with an efficient CDMA based MAC protocol can significantly increase the performance of the system while lowering the energy dissipation in data transfer. In this work it is shown that the wireless NoC with the proposed CDMA based MAC protocol

  1. Optical multiple access techniques for on-board routing

    NASA Astrophysics Data System (ADS)

    Mendez, Antonio J.; Park, Eugene; Gagliardi, Robert M.

    1992-03-01

    The purpose of this research contract was to design and analyze an optical multiple access system, based on Code Division Multiple Access (CDMA) techniques, for on board routing applications on a future communication satellite. The optical multiple access system was to effect the functions of a circuit switch under the control of an autonomous network controller and to serve eight (8) concurrent users at a point to point (port to port) data rate of 180 Mb/s. (At the start of this program, the bit error rate requirement (BER) was undefined, so it was treated as a design variable during the contract effort.) CDMA was selected over other multiple access techniques because it lends itself to bursty, asynchronous, concurrent communication and potentially can be implemented with off the shelf, reliable optical transceivers compatible with long term unattended operations. Temporal, temporal/spatial hybrids and single pulse per row (SPR, sometimes termed 'sonar matrices') matrix types of CDMA designs were considered. The design, analysis, and trade offs required by the statement of work selected a temporal/spatial CDMA scheme which has SPR properties as the preferred solution. This selected design can be implemented for feasibility demonstration with off the shelf components (which are identified in the bill of materials of the contract Final Report). The photonic network architecture of the selected design is based on M(8,4,4) matrix codes. The network requires eight multimode laser transmitters with laser pulses of 0.93 ns operating at 180 Mb/s and 9-13 dBm peak power, and 8 PIN diode receivers with sensitivity of -27 dBm for the 0.93 ns pulses. The wavelength is not critical, but 830 nm technology readily meets the requirements. The passive optical components of the photonic network are all multimode and off the shelf. Bit error rate (BER) computations, based on both electronic noise and intercode crosstalk, predict a raw BER of (10 exp -3) when all eight users are

  2. Optical multiple access techniques for on-board routing

    NASA Technical Reports Server (NTRS)

    Mendez, Antonio J.; Park, Eugene; Gagliardi, Robert M.

    1992-01-01

    The purpose of this research contract was to design and analyze an optical multiple access system, based on Code Division Multiple Access (CDMA) techniques, for on board routing applications on a future communication satellite. The optical multiple access system was to effect the functions of a circuit switch under the control of an autonomous network controller and to serve eight (8) concurrent users at a point to point (port to port) data rate of 180 Mb/s. (At the start of this program, the bit error rate requirement (BER) was undefined, so it was treated as a design variable during the contract effort.) CDMA was selected over other multiple access techniques because it lends itself to bursty, asynchronous, concurrent communication and potentially can be implemented with off the shelf, reliable optical transceivers compatible with long term unattended operations. Temporal, temporal/spatial hybrids and single pulse per row (SPR, sometimes termed 'sonar matrices') matrix types of CDMA designs were considered. The design, analysis, and trade offs required by the statement of work selected a temporal/spatial CDMA scheme which has SPR properties as the preferred solution. This selected design can be implemented for feasibility demonstration with off the shelf components (which are identified in the bill of materials of the contract Final Report). The photonic network architecture of the selected design is based on M(8,4,4) matrix codes. The network requires eight multimode laser transmitters with laser pulses of 0.93 ns operating at 180 Mb/s and 9-13 dBm peak power, and 8 PIN diode receivers with sensitivity of -27 dBm for the 0.93 ns pulses. The wavelength is not critical, but 830 nm technology readily meets the requirements. The passive optical components of the photonic network are all multimode and off the shelf. Bit error rate (BER) computations, based on both electronic noise and intercode crosstalk, predict a raw BER of (10 exp -3) when all eight users are

  3. Emergency access for online personally controlled health records system.

    PubMed

    Zhang, Yuan; Dhileepan, Sunethra; Schmidt, Matthew; Zhong, Sheng

    2012-09-01

    A personally controlled health records (PCHR) system allows a patient user to share his/her health records with trusted physicians by manually granting them the access privilege to his/her online records. However, it presents the problem of emergency access in situations where the user is physically unable to grant the access and the access is required by an Emergency Room (ER) physician who does not have the privilege at that moment. To deal with such a problem, we introduce an online polling system to provide the emergency access control to PCHR systems. For each emergency access request, the access privilege is controlled according to the combined opinions of the patient's preset emergency contacts and other online registered physicians. Because our system is based on the demographic number of the physician community nationwide, it provides a stable emergency access control at all times.

  4. What's Hot--and Not--in Card Access Systems.

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2002-01-01

    Describes four uses of newer card access systems on college campuses: stored value, entitlement, access control, and vending. Discusses the continued reluctance of schools to move to cards containing computer chips rather than simply magnetic stripes. (EV)

  5. Embedded systems for supporting computer accessibility.

    PubMed

    Mulfari, Davide; Celesti, Antonio; Fazio, Maria; Villari, Massimo; Puliafito, Antonio

    2015-01-01

    Nowadays, customized AT software solutions allow their users to interact with various kinds of computer systems. Such tools are generally available on personal devices (e.g., smartphones, laptops and so on) commonly used by a person with a disability. In this paper, we investigate a way of using the aforementioned AT equipments in order to access many different devices without assistive preferences. The solution takes advantage of open source hardware and its core component consists of an affordable Linux embedded system: it grabs data coming from the assistive software, which runs on the user's personal device, then, after processing, it generates native keyboard and mouse HID commands for the target computing device controlled by the end user. This process supports any operating system available on the target machine and it requires no specialized software installation; therefore the user with a disability can rely on a single assistive tool to control a wide range of computing platforms, including conventional computers and many kinds of mobile devices, which receive input commands through the USB HID protocol. PMID:26294501

  6. Concept and implementation of the Globalstar mobile satellite system

    NASA Technical Reports Server (NTRS)

    Schindall, Joel

    1995-01-01

    Globalstar is a satellite-based mobile communications system which provides quality wireless communications (voice and/or data) anywhere in the world except the polar regions. The Globalstar system concept is based upon technological advancements in Low Earth Orbit (LEO) satellite technology and in cellular telephone technology, including the commercial application of Code Division Multiple Access (CDMA) technologies. The Globalstar system uses elements of CDMA and Frequency Division Multiple Access (FDMA), combined with satellite Multiple Beam Antenna (MBA) technology and advanced variable-rate vocoder technology to arrive at one of the most efficient modulation and multiple access systems ever proposed for a satellite communications system. The technology used in Globalstar includes the following techniques in obtaining high spectral efficiency and affordable cost per channel: (1) CDMA modulation with efficient power control; (2) high efficiency vocoder with voice activity factor; (3) spot beam antenna for increased gain and frequency reuse; (4) weighted satellite antenna gain for broad geographic coverage; (5) multisatellite user links (diversity) to enhance communications reliability; and (6) soft hand-off between beams and satellites. Initial launch is scheduled in 1997 and the system is scheduled to be operational in 1998. The Globalstar system utilizes frequencies in L-, S- and C-bands which have the potential to offer worldwide availability with authorization by the appropriate regulatory agencies.

  7. Context-Based E-Health System Access Control Mechanism

    NASA Astrophysics Data System (ADS)

    Al-Neyadi, Fahed; Abawajy, Jemal H.

    E-Health systems logically demand a sufficiently fine-grained authorization policy for access control. The access to medical information should not be just role-based but should also include the contextual condition of the role to access data. In this paper, we present a mechanism to extend the standard role-based access control to incorporate contextual information for making access control decisions in e-health application. We present an architecture consisting of authorisation and context infrastructure that work cooperatively to grant access rights based on context-aware authorization policies and context information.

  8. Quantum internet using code division multiple access.

    PubMed

    Zhang, Jing; Liu, Yu-xi; Ozdemir, Sahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

    2013-01-01

    A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels.

  9. Quantum internet using code division multiple access

    PubMed Central

    Zhang, Jing; Liu, Yu-xi; Özdemir, Şahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

    2013-01-01

    A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels. PMID:23860488

  10. Multiple access capacity trade-offs for a Ka-band personal access satellite system

    NASA Technical Reports Server (NTRS)

    Dessouky, Khaled; Motamedi, Masoud

    1990-01-01

    System capability is critical to the economic viability of a personal satellite communication system. Ka band has significant potential to support a high capacity multiple access system because of the availability of bandwidth. System design tradeoffs are performed and multiple access schemes are compared with the design goal of achieving the highest capacity and efficiency. Conclusions regarding the efficiency of the different schemes and the achievable capacities are given.

  11. A study of multiple access schemes in satellite control network

    NASA Astrophysics Data System (ADS)

    Mo, Zijian; Wang, Zhonghai; Xiang, Xingyu; Wang, Gang; Chen, Genshe; Nguyen, Tien; Pham, Khanh; Blasch, Erik

    2016-05-01

    Satellite Control Networks (SCN) have provided launch control for space lift vehicles; tracking, telemetry and commanding (TTC) for on-orbit satellites; and, test support for space experiments since the 1960s. Currently, SCNs encounter a new challenge: how to maintain the high reliability of services when sharing the spectrum with emerging commercial services. To achieve this goal, the capability of multiple satellites reception is deserved as an update/modernization of SCN in the future. In this paper, we conducts an investigation of multiple access techniques in SCN scenario, e.g., frequency division multiple access (FDMA) and coded division multiple access (CDMA). First, we introduce two upgrade options of SCN based on FDMA and CDMA techniques. Correspondingly, we also provide their performance analysis, especially the system improvement in spectrum efficiency and interference mitigation. Finally, to determine the optimum upgrade option, this work uses CRISP, i.e., Cost, Risk, Installation, Supportability and Performance, as the baseline approach for a comprehensive trade study of these two options. Extensive numerical and simulation results are presented to illustrate the theoretical development.

  12. Cancer Data Access System (CDAS) | Division of Cancer Prevention

    Cancer.gov

    The Cancer Data Access System (CDAS) is a web portal that facilitates access to PLCO data. Investigators can register with CDAS and request access to data collected through December 31, 2009 for the first 13 years of participation for each subject in the PLCO trial. Newly diagnosed cancers and deaths continue to be collected and will be available in the future. |

  13. Modeling mandatory access control in role-based security systems

    SciTech Connect

    Nyanchama, M.; Osborn, S.

    1996-12-31

    This paper discusses the realization of mandatory access control in role-based protection systems. Starting from the basic definitions of roles, their application in security and the basics of the concept of mandatory access control, we develop a scheme of role-based protection that realizes mandatory access control. The basis of this formulation develops from the recognition that roles can be seen as facilitating access to some given information context. By handling each of the role contexts as independent security levels of information, we simulate mandatory access by imposing the requirements of mandatory access control. Among the key considerations, we propose a means of taming Trojan horses by imposing acyclic information flow among contexts in role-based protection systems. The acyclic information flows and suitable access rules incorporate secrecy which is an essential component of mandatory access control.

  14. A Digitally Addressable Random-Access Image Selector and Random-Access Audio System.

    ERIC Educational Resources Information Center

    Bitzer, Donald L.; And Others

    The requirements of PLATO IV, a computer based education system at the University of Illinois, have led to the development of an improved, digitally addressable, random access image selector and a digitally addressable, random access audio device. Both devices utilize pneumatically controlled mechanical binary adders to position the mecahnical…

  15. Integrated semiconductor-magnetic random access memory system

    NASA Technical Reports Server (NTRS)

    Katti, Romney R. (Inventor); Blaes, Brent R. (Inventor)

    2001-01-01

    The present disclosure describes a non-volatile magnetic random access memory (RAM) system having a semiconductor control circuit and a magnetic array element. The integrated magnetic RAM system uses CMOS control circuit to read and write data magnetoresistively. The system provides a fast access, non-volatile, radiation hard, high density RAM for high speed computing.

  16. InfoTrac: An Inhouse Computer-Access System.

    ERIC Educational Resources Information Center

    Carney, Richard

    1985-01-01

    InfoTrac is a laserdisc system that provides local computer-access to Information Access Company's periodical databases and offers libraries an extensive, self-contained reference system. The system, which employs an IBM PC microcomputer, a Hewlett-Packard Thinkjet printer, and a Pioneer videodisc player, provides advantages of online searching at…

  17. Health information system access control redesign - rationale and method.

    PubMed

    Moselle, Kenneth A

    2011-01-01

    This paper addresses the question of why a health service system might find it necessary to re-engineer the access control model that mediates the interaction of clinicians with health information systems. Factors that lead to increasingly complexity of the access control models are delineated, and consequences of that complexity are identified. Strategies are presented to address these factors, and a stepwise procedure is suggested to structure the access control model re-engineering process.

  18. 49 CFR 1542.207 - Access control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 9 2014-10-01 2014-10-01 false Access control systems. 1542.207 Section 1542.207..., DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRPORT SECURITY Operations § 1542.207 Access control systems. (a) Secured area. Except as provided in paragraph (b) of this section, the measures...

  19. 49 CFR 1542.207 - Access control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 9 2013-10-01 2013-10-01 false Access control systems. 1542.207 Section 1542.207..., DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRPORT SECURITY Operations § 1542.207 Access control systems. (a) Secured area. Except as provided in paragraph (b) of this section, the measures...

  20. 49 CFR 1542.207 - Access control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 9 2011-10-01 2011-10-01 false Access control systems. 1542.207 Section 1542.207..., DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRPORT SECURITY Operations § 1542.207 Access control systems. (a) Secured area. Except as provided in paragraph (b) of this section, the measures...

  1. 49 CFR 1542.207 - Access control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Access control systems. 1542.207 Section 1542.207..., DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRPORT SECURITY Operations § 1542.207 Access control systems. (a) Secured area. Except as provided in paragraph (b) of this section, the measures...

  2. 49 CFR 1542.207 - Access control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 9 2012-10-01 2012-10-01 false Access control systems. 1542.207 Section 1542.207..., DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRPORT SECURITY Operations § 1542.207 Access control systems. (a) Secured area. Except as provided in paragraph (b) of this section, the measures...

  3. Program Retrieval/Dissemination: A Solid State Random Access System.

    ERIC Educational Resources Information Center

    Weeks, Walter O., Jr.

    The trend toward greater flexibility in educational methods has led to a need for better and more rapid access to a variety of aural and audiovisual resource materials. This in turn has demanded the development of a flexible, reliable system of hardware designed to aid existing distribution methods in providing such access. The system must be…

  4. Analysis of Access Control Policies in Operating Systems

    ERIC Educational Resources Information Center

    Chen, Hong

    2009-01-01

    Operating systems rely heavily on access control mechanisms to achieve security goals and defend against remote and local attacks. The complexities of modern access control mechanisms and the scale of policy configurations are often overwhelming to system administrators and software developers. Therefore, mis-configurations are common, and the…

  5. DOA estimation for local scattered CDMA signals by particle swarm optimization.

    PubMed

    Chang, Jhih-Chung

    2012-01-01

    This paper deals with the direction-of-arrival (DOA) estimation of local scattered code-division multiple access (CDMA) signals based on a particle swarm optimization (PSO) search. For conventional spectral searching estimators with local scattering, the searching complexity and estimating accuracy strictly depend on the number of search grids used during the search. In order to obtain high-resolution and accurate DOA estimation, a smaller grid size is needed. This is time consuming and it is unclear how to determine the required number of search grids. In this paper, a modified PSO is presented to reduce the required search grids for the conventional spectral searching estimator with the effects of local scattering. Finally, several computer simulations are provided for illustration and comparison.

  6. A self-learning call admission control scheme for CDMA cellular networks.

    PubMed

    Liu, Derong; Zhang, Yi; Zhang, Huaguang

    2005-09-01

    In the present paper, a call admission control scheme that can learn from the network environment and user behavior is developed for code division multiple access (CDMA) cellular networks that handle both voice and data services. The idea is built upon a novel learning control architecture with only a single module instead of two or three modules in adaptive critic designs (ACDs). The use of adaptive critic approach for call admission control in wireless cellular networks is new. The call admission controller can perform learning in real-time as well as in offline environments and the controller improves its performance as it gains more experience. Another important contribution in the present work is the choice of utility function for the present self-learning control approach which makes the present learning process much more efficient than existing learning control methods. The performance of our algorithm will be shown through computer simulation and compared with existing algorithms. PMID:16252828

  7. Speed control system for an access gate

    SciTech Connect

    Bzorgi, Fariborz M.

    2012-03-20

    An access control apparatus for an access gate. The access gate typically has a rotator that is configured to rotate around a rotator axis at a first variable speed in a forward direction. The access control apparatus may include a transmission that typically has an input element that is operatively connected to the rotator. The input element is generally configured to rotate at an input speed that is proportional to the first variable speed. The transmission typically also has an output element that has an output speed that is higher than the input speed. The input element and the output element may rotate around a common transmission axis. A retardation mechanism may be employed. The retardation mechanism is typically configured to rotate around a retardation mechanism axis. Generally the retardation mechanism is operatively connected to the output element of the transmission and is configured to retard motion of the access gate in the forward direction when the first variable speed is above a control-limit speed. In many embodiments the transmission axis and the retardation mechanism axis are substantially co-axial. Some embodiments include a freewheel/catch mechanism that has an input connection that is operatively connected to the rotator. The input connection may be configured to engage an output connection when the rotator is rotated at the first variable speed in a forward direction and configured for substantially unrestricted rotation when the rotator is rotated in a reverse direction opposite the forward direction. The input element of the transmission is typically operatively connected to the output connection of the freewheel/catch mechanism.

  8. Doppler compensated underwater acoustic communication system

    NASA Astrophysics Data System (ADS)

    Raj, Anand; George, Binu; Supiya, M. H.; Kurian, James; Pillai, P. R. Saseendran

    2001-05-01

    Spread spectrum methods are used in communication systems to provide a low probability of intercept in hostile environments and multiple access capability in systems shared by many users as well as to provide high processing gain in channels where the transmitted signal is distorted by multipath effects. Such systems serve to be an effective tool for underwater telemetry environments, where multipath propagation effect and Doppler spreading is seen to be more predominant. This paper describes the implementation of a Doppler compensated underwater telemetry system based on CDMA technique. The system consists of multiple CDMA transmitters and a phase locked loop based carrier recoverable CDMA receiver. The effects of the Doppler shift can be compensated by the carrier recovery subsystem in the demodulator, based on PLL technique, which extracts the carrier frequency/phase and simultaneously demodulates the signal. The decision device in the receiver consists of a PN sequence generator as well as a bank of correlators, which are used to determine the data transmitted. The system simulation has been implemented in MATLAB. The advantage of this system is that multiple transmitting stations can transmit simultaneously to a central receiver, thereby increasing the system throughput.

  9. A Brief Survey of Media Access Control, Data Link Layer, and Protocol Technologies for Lunar Surface Communications

    NASA Technical Reports Server (NTRS)

    Wallett, Thomas M.

    2009-01-01

    This paper surveys and describes some of the existing media access control and data link layer technologies for possible application in lunar surface communications and the advanced wideband Direct Sequence Code Division Multiple Access (DSCDMA) conceptual systems utilizing phased-array technology that will evolve in the next decade. Time Domain Multiple Access (TDMA) and Code Division Multiple Access (CDMA) are standard Media Access Control (MAC) techniques that can be incorporated into lunar surface communications architectures. Another novel hybrid technique that is recently being developed for use with smart antenna technology combines the advantages of CDMA with those of TDMA. The relatively new and sundry wireless LAN data link layer protocols that are continually under development offer distinct advantages for lunar surface applications over the legacy protocols which are not wireless. Also several communication transport and routing protocols can be chosen with characteristics commensurate with smart antenna systems to provide spacecraft communications for links exhibiting high capacity on the surface of the Moon. The proper choices depend on the specific communication requirements.

  10. Multi-Sensor Detection with Particle Swarm Optimization for Time-Frequency Coded Cooperative WSNs Based on MC-CDMA for Underground Coal Mines.

    PubMed

    Xu, Jingjing; Yang, Wei; Zhang, Linyuan; Han, Ruisong; Shao, Xiaotao

    2015-08-27

    In this paper, a wireless sensor network (WSN) technology adapted to underground channel conditions is developed, which has important theoretical and practical value for safety monitoring in underground coal mines. According to the characteristics that the space, time and frequency resources of underground tunnel are open, it is proposed to constitute wireless sensor nodes based on multicarrier code division multiple access (MC-CDMA) to make full use of these resources. To improve the wireless transmission performance of source sensor nodes, it is also proposed to utilize cooperative sensors with good channel conditions from the sink node to assist source sensors with poor channel conditions. Moreover, the total power of the source sensor and its cooperative sensors is allocated on the basis of their channel conditions to increase the energy efficiency of the WSN. To solve the problem that multiple access interference (MAI) arises when multiple source sensors transmit monitoring information simultaneously, a kind of multi-sensor detection (MSD) algorithm with particle swarm optimization (PSO), namely D-PSO, is proposed for the time-frequency coded cooperative MC-CDMA WSN. Simulation results show that the average bit error rate (BER) performance of the proposed WSN in an underground coal mine is improved significantly by using wireless sensor nodes based on MC-CDMA, adopting time-frequency coded cooperative transmission and D-PSO algorithm with particle swarm optimization.

  11. Multi-Sensor Detection with Particle Swarm Optimization for Time-Frequency Coded Cooperative WSNs Based on MC-CDMA for Underground Coal Mines

    PubMed Central

    Xu, Jingjing; Yang, Wei; Zhang, Linyuan; Han, Ruisong; Shao, Xiaotao

    2015-01-01

    In this paper, a wireless sensor network (WSN) technology adapted to underground channel conditions is developed, which has important theoretical and practical value for safety monitoring in underground coal mines. According to the characteristics that the space, time and frequency resources of underground tunnel are open, it is proposed to constitute wireless sensor nodes based on multicarrier code division multiple access (MC-CDMA) to make full use of these resources. To improve the wireless transmission performance of source sensor nodes, it is also proposed to utilize cooperative sensors with good channel conditions from the sink node to assist source sensors with poor channel conditions. Moreover, the total power of the source sensor and its cooperative sensors is allocated on the basis of their channel conditions to increase the energy efficiency of the WSN. To solve the problem that multiple access interference (MAI) arises when multiple source sensors transmit monitoring information simultaneously, a kind of multi-sensor detection (MSD) algorithm with particle swarm optimization (PSO), namely D-PSO, is proposed for the time-frequency coded cooperative MC-CDMA WSN. Simulation results show that the average bit error rate (BER) performance of the proposed WSN in an underground coal mine is improved significantly by using wireless sensor nodes based on MC-CDMA, adopting time-frequency coded cooperative transmission and D-PSO algorithm with particle swarm optimization. PMID:26343660

  12. Multi-Sensor Detection with Particle Swarm Optimization for Time-Frequency Coded Cooperative WSNs Based on MC-CDMA for Underground Coal Mines.

    PubMed

    Xu, Jingjing; Yang, Wei; Zhang, Linyuan; Han, Ruisong; Shao, Xiaotao

    2015-01-01

    In this paper, a wireless sensor network (WSN) technology adapted to underground channel conditions is developed, which has important theoretical and practical value for safety monitoring in underground coal mines. According to the characteristics that the space, time and frequency resources of underground tunnel are open, it is proposed to constitute wireless sensor nodes based on multicarrier code division multiple access (MC-CDMA) to make full use of these resources. To improve the wireless transmission performance of source sensor nodes, it is also proposed to utilize cooperative sensors with good channel conditions from the sink node to assist source sensors with poor channel conditions. Moreover, the total power of the source sensor and its cooperative sensors is allocated on the basis of their channel conditions to increase the energy efficiency of the WSN. To solve the problem that multiple access interference (MAI) arises when multiple source sensors transmit monitoring information simultaneously, a kind of multi-sensor detection (MSD) algorithm with particle swarm optimization (PSO), namely D-PSO, is proposed for the time-frequency coded cooperative MC-CDMA WSN. Simulation results show that the average bit error rate (BER) performance of the proposed WSN in an underground coal mine is improved significantly by using wireless sensor nodes based on MC-CDMA, adopting time-frequency coded cooperative transmission and D-PSO algorithm with particle swarm optimization. PMID:26343660

  13. ACCESS: Design and Sub-System Performance

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary Elizabeth; Morris, Matthew J.; McCandliss, Stephan R.; Rasucher, Bernard J.; Kimble, Randy A.; Kruk, Jeffrey W.; Pelton, Russell; Mott, D. Brent; Wen, Hiting; Foltz, Roger; Quijada, Manuel A.; Gum, Jeffery S.; Gardner, Jonathan P.; Kahle, Duncan M.; Benford, Dominic J.; Woodgate, Bruce E.; Wright, Edward L.; Feldman, Paul D.; Hart, Murdock; Moos, H. Warren; Reiss, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, W. V.; Sahnow, David J.

    2012-01-01

    Establishing improved spectrophotometric standards is important for a broad range of missions and is relevant to many astrophysical problems. ACCESS, "Absolute Color Calibration Experiment for Standard Stars", is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 -1.7 micrometer bandpass.

  14. Task Delegation Based Access Control Models for Workflow Systems

    NASA Astrophysics Data System (ADS)

    Gaaloul, Khaled; Charoy, François

    e-Government organisations are facilitated and conducted using workflow management systems. Role-based access control (RBAC) is recognised as an efficient access control model for large organisations. The application of RBAC in workflow systems cannot, however, grant permissions to users dynamically while business processes are being executed. We currently observe a move away from predefined strict workflow modelling towards approaches supporting flexibility on the organisational level. One specific approach is that of task delegation. Task delegation is a mechanism that supports organisational flexibility, and ensures delegation of authority in access control systems. In this paper, we propose a Task-oriented Access Control (TAC) model based on RBAC to address these requirements. We aim to reason about task from organisational perspectives and resources perspectives to analyse and specify authorisation constraints. Moreover, we present a fine grained access control protocol to support delegation based on the TAC model.

  15. A secure network access system for mobile IPv6

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Yuan, Man; He, Rui; Jiang, Luliang; Ma, Jian; Qian, Hualin

    2004-03-01

    With the fast development of Internet and wireless and mobile communication technology, the Mobile Internet Age is upcoming. For those providing Mobile Internet services, especially from the view of ISP (Internet Service Provider), current mobile IP protocol is insufficient. Since the Mobile IPv6 protocol will be popular in near future, how to provide a secure mobile IPv6 service is important. A secure mobile IPv6 network access system is highly needed for mobile IPv6 deployment. Current methods and systems are still inadequate, including EAP, PANA, 802.1X, RADIUS, Diameter, etc. In this paper, we describe main security goals for a secure mobile IPv6 access system, and propose a secure network access system to achieve them. This access system consists of access router, attendant and authentication servers. The access procedure is divided into three phases, which are initial phase, authentication and registration phase and termination phase. This system has many advantages, including layer two independent, flexible and extensible, no need to modify current IPv6 address autoconfiguration protocols, binding update optimization, etc. Finally, the security of the protocol in this system is analyzed and proved with Extended BAN logic method, and a brief introduction of system implementation is given.

  16. BCH codes for large IC random-access memory systems

    NASA Technical Reports Server (NTRS)

    Lin, S.; Costello, D. J., Jr.

    1983-01-01

    In this report some shortened BCH codes for possible applications to large IC random-access memory systems are presented. These codes are given by their parity-check matrices. Encoding and decoding of these codes are discussed.

  17. Mobile satellite business networks: A part of the European mobile system

    NASA Technical Reports Server (NTRS)

    deMateo, M. L.; Jongejans, A.; Loisy, C.; VanHimbeeck, C.; Marchal, J. P.; Borella, A.; Sartori, M.

    1995-01-01

    The European Space Agency (ESA) is presently procuring an L-band payload EMS, to be embarked on the ITALSAT-2 satellite due for launch in early 1996, in order to promote a regional European mobile system. One of the Land Mobile Communication systems supported by EMS is the MSBN (Mobile Satellite Business Network) voice and data system which will offer the services of a business network on a seamless European coverage. This paper will first recall the characteristics of the MSBN system, which is based on quasi-synchronized CDMA (Code Division Multiple Access) techniques in both directions, and then describe the CDMA receivers implementation. Main validation test results will also be reported confirming predicted performances.

  18. Evaluation of parameters of oxidative stress after in vitro exposure to FMCW- and CDMA-modulated radiofrequency radiation fields.

    PubMed

    Hook, Graham J; Spitz, Douglas R; Sim, Julia E; Higashikubo, Ryuji; Baty, Jack D; Moros, Eduardo G; Roti Roti, Joseph L

    2004-11-01

    The goal of this study was to determine whether radiofrequency (RF) radiation is capable of inducing oxidative stress or affecting the response to oxidative stress in cultured mammalian cells. The two types of RF radiation investigated were frequency-modulated continuous-wave with a carrier frequency of 835.62 MHz (FMCW) and code division multiple access centered on 847.74 MHz (CDMA). To evaluate the effect of RF radiation on oxidative stress, J774.16 mouse macrophage cells were stimulated with gamma-interferon (IFN) and bacterial lipopolysaccharide (LPS) prior to exposure. Cell cultures were exposed for 20-22 h to a specific absorption rate of 0.8 W/kg at a temperature of 37.0 +/- 0.3 degrees C. Oxidative stress was evaluated by measuring oxidant levels, antioxidant levels, oxidative damage and nitric oxide production. Oxidation of thiols was measured by monitoring the accumulation of glutathione disulfide (GSSG). Cellular antioxidant defenses were evaluated by measuring superoxide dismutase activity (CuZnSOD and MnSOD) as well as catalase and glutathione peroxidase activity. The trypan blue dye exclusion assay was used to measure any changes in viability. The results of these studies indicated that FMCW- and CDMA-modulated RF radiation did not alter parameters indicative of oxidative stress in J774.16 cells. FMCW- and CDMA-modulated fields did not alter the level of intracellular oxidants, accumulation of GSSG or induction of antioxidant defenses in IFN/LPS-stimulated cells. Consistent with the lack of an effect on oxidative stress parameters, no change in toxicity was observed in J774.16 cells after either optimal (with or without inhibitors of nitric oxide synthase) or suboptimal stimulation. PMID:15624304

  19. Cancer Data Access System (CDAS) | Division of Cancer Prevention

    Cancer.gov

    The Cancer Data Access System (CDAS) is a submission and tracking system for the use of data from the National Lung Screening Trial (NLST) and the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.Interested investigators can register with CDAS and request access to data from either screening trial. All requests are reviewed by NCI trial leadership. Upon approval, investigators will be granted access to the requested data for a limited period. | Submission and tracking for data from the National Lung Screening Trial (NLST) and the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO).

  20. Healthcare professionals' experiences with EHR-system access control mechanisms.

    PubMed

    Faxvaag, Arild; Johansen, Trond S; Heimly, Vigdis; Melby, Line; Grimsmo, Anders

    2011-01-01

    Access control mechanisms might influence on the information seeking and documentation behavior of clinicians. In this study, we have surveyed healthcare professionals in nursing homes and hospitals on their attitudes to, and experiences with using access control mechanisms. In some situations, the access control mechanisms of the EHR system made clinicians postpone documentation work. Their practice of reading what others have documented was also influenced. Not all clinicians logged out of the system when they left a workstation, and some clinicians reported to do some of their documentation work in the name of others. The reported practices might have implications for the safety of the patient.

  1. The implementation of wireless access in EPON system

    NASA Astrophysics Data System (ADS)

    Chang, Yuguang; Liu, Deming; Wu, Guangsheng

    2008-11-01

    Ethernet Passive Optical Network(EPON) is one of the most promising fibre-based access techniques which has been more and more widely used in today's access networks. In this paper, we proposed to integrate WLAN technology with EPON to provide wireless service in EPON network. First of all, theoretical analysis is given to support the feasibility of integrating WLAN technology into EPON system. Then, the architecture of the integrated system is descried. The key point of the plan is that an integrated ONU and WLAN BS called ONU-WLAN AP is setup in the system instead of a standard ONU. This is also the main difference between proposed system and a normal EPON system. The ONU-WLAN AP can provide both wired access and wireless access to the end users. System design and implementation is discussed in the following paragraph. Transmission experiments and results of the proposed plan are also described in this paper. The experimental results show that the average traffic throughput of the system could reach to approximate 20Mbps. Finally, conclusions are drawn out: The proposed system can work properly. The integrated system could be a costeffective plan for broadband access network.

  2. Personnel Access Control System Evaluation for National Ignition Facility Operations

    SciTech Connect

    Altenbach, T; Brereton, S.; Hermes, G.; Singh, M.

    2001-06-01

    The purpose of this document is to analyze the baseline Access Control System for the National Ignition Facility (NIF), and to assess its effectiveness at controlling access to hazardous locations during full NIF operations. It reviews the various hazards present during a NIF shot sequence, and evaluates the effectiveness of the applicable set of controls at preventing access while the hazards are present. It considers only those hazards that could potentially be lethal. In addition, various types of technologies that might be applicable at NIF are reviewed, as are systems currently in use at other facilities requiring access control for safety reasons. Recommendations on how this system might be modified to reduce risk are made.

  3. Launch system design for access to space

    NASA Technical Reports Server (NTRS)

    Barnes, Corbin

    1994-01-01

    Here, a hybrid launch system is developed. The hybrid launch system combines the lower operating cost advantage of an non-man-rated SSTO (Single Stage to Orbit) MLV (Medium Launch Vehicle) with the crew survivability advantage of a ballistic escape pod. Ultimately, it was found that a non-man-made MLV is configured the same as a man-rated MLV and offers no significant savings in operational cost. However, addition of the proposed escape system would increase the crew survivability rate of the SSTO while incurring only a small cost per pound payload penalty.

  4. Flexible format, computer accessed telemetry system

    NASA Technical Reports Server (NTRS)

    Easton, R. A.; Hilbert, E. E.

    1973-01-01

    With this system, it is possible to sample and generate two or more simultaneous formats; one can be transmitted to ground station in real time, and other is stored for later transmission. Sensor output comparison data, plus information to control format, compression algorithm, and allowable degree of sensor activity, are stored in memory.

  5. Remotely Accessed Vehicle Traffic Management System

    NASA Astrophysics Data System (ADS)

    Al-Alawi, Raida

    2010-06-01

    The ever increasing number of vehicles in most metropolitan cities around the world and the limitation in altering the transportation infrastructure, led to serious traffic congestion and an increase in the travelling time. In this work we exploit the emergence of novel technologies such as the internet, to design an intelligent Traffic Management System (TMS) that can remotely monitor and control a network of traffic light controllers located at different sites. The system is based on utilizing Embedded Web Servers (EWS) technology to design a web-based TMS. The EWS located at each intersection uses IP technology for communicating remotely with a Central Traffic Management Unit (CTMU) located at the traffic department authority. Friendly GUI software installed at the CTMU will be able to monitor the sequence of operation of the traffic lights and the presence of traffic at each intersection as well as remotely controlling the operation of the signals. The system has been validated by constructing a prototype that resembles the real application.

  6. Open Access: How Is Scholarly Information Service System Going?

    NASA Astrophysics Data System (ADS)

    Xia, Nanqiang; Zhang, Yaokun

    Open access movement has resulted in a change of the entire scholarly communication environment. Scholarly information service system (SISS) had a significant change which is represented in the emergency of various open access publishing mode and diversification of integrated value-added service providers. This paper analyzed this change, and discussed how academic library should react to the change; also some possible impacts on scientific communication were discussed.

  7. ISAIA: Interoperable Systems for Archival Information Access

    NASA Technical Reports Server (NTRS)

    Hanisch, Robert J.

    2002-01-01

    The ISAIA project was originally proposed in 1999 as a successor to the informal AstroBrowse project. AstroBrowse, which provided a data location service for astronomical archives and catalogs, was a first step toward data system integration and interoperability. The goals of ISAIA were ambitious: '...To develop an interdisciplinary data location and integration service for space science. Building upon existing data services and communications protocols, this service will allow users to transparently query hundreds or thousands of WWW-based resources (catalogs, data, computational resources, bibliographic references, etc.) from a single interface. The service will collect responses from various resources and integrate them in a seamless fashion for display and manipulation by the user.' Funding was approved only for a one-year pilot study, a decision that in retrospect was wise given the rapid changes in information technology in the past few years and the emergence of the Virtual Observatory initiatives in the US and worldwide. Indeed, the ISAIA pilot study was influential in shaping the science goals, system design, metadata standards, and technology choices for the virtual observatory. The ISAIA pilot project also helped to cement working relationships among the NASA data centers, US ground-based observatories, and international data centers. The ISAIA project was formed as a collaborative effort between thirteen institutions that provided data to astronomers, space physicists, and planetary scientists. Among the fruits we ultimately hoped would come from this project would be a central site on the Web that any space scientist could use to efficiently locate existing data relevant to a particular scientific question. Furthermore, we hoped that the needed technology would be general enough to allow smaller, more-focused community within space science could use the same technologies and standards to provide more specialized services. A major challenge to searching

  8. 40 CFR 35.2110 - Access to individual systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Access to individual systems. 35.2110 Section 35.2110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... the systems at all reasonable times for such purposes as inspection, monitoring, building,...

  9. 40 CFR 35.2110 - Access to individual systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Access to individual systems. 35.2110 Section 35.2110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... the systems at all reasonable times for such purposes as inspection, monitoring, building,...

  10. 40 CFR 35.2110 - Access to individual systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Access to individual systems. 35.2110 Section 35.2110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... the systems at all reasonable times for such purposes as inspection, monitoring, building,...

  11. Open Access: A User Information System. Professional Paper Series, #6.

    ERIC Educational Resources Information Center

    Gleason, Bernard W.

    Focusing on the need for information systems that provide faculty, staff, and students with open access to all necessary information resources, this paper begins by discussing the issues involved in developing such systems. A review of the traditional environment looks at the traditional centralized resources versus the current trend toward…

  12. Accessing the Food Systems in Urban and Rural Minnesotan Communities

    ERIC Educational Resources Information Center

    Smith, Chery; Miller, Hannah

    2011-01-01

    Objective: Explore how urban and rural Minnesotans access the food system and to investigate whether community infrastructure supports a healthful food system. Design: Eight (4 urban and 4 rural) focus groups were conducted. Setting and Participants: Eight counties with urban influence codes of 1, 2, 4, 5, 8, and 10. Fifty-nine (urban, n = 27;…

  13. 61. View of TR spiral access stair system from transmitter ...

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

    61. View of TR spiral access stair system from transmitter building no. 102 mezzanine level; note elevator door on right. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  14. Performance analysis of turbo decoder on the W-CDMA uplink layer

    NASA Astrophysics Data System (ADS)

    Fang, Xin; Gao, Xiqi; You, XiaoHu

    2001-10-01

    Turbo code is widely noticed as a code that can achieve the performance close to Shannon's limit. Turbo code (k=3) and Convolutional code (k=9) are adopted for channel coding units of WCDMA standard. The Turbo code is expected for the system of high rate data transmission in view of performance and hardware complexity. In this paper, the simulation platform of W-CDMA uplink is developed by the EDA tool-COSSAP. Channel model is M.1225 with 6 fingers model estimated by channel estimator on the Base Station using discontinuous pilot channel with different pilot modes. The BER simulation performance of turbo decoder based on Log-MAP algorithm under frequency selective fading channel is presented in comparison with conventional Viterbi decoder. The simulation results show that in the case of enough accurate estimation of channel parameters, Turbo decoder has better BER performance at high Eb/N0 than conventional Viterbi decoder.

  15. Hippo Experiment Data Access and Subseting System

    NASA Astrophysics Data System (ADS)

    Krassovski, M.; Hook, L.; Boden, T.

    2014-12-01

    HIAPER Pole-to-Pole Observations (HIPPO) was an NSF- and NOAA-funded, multi-year global airborne research project to survey the latitudinal and vertical distribution of greenhouse and related gases, and aerosols. Project scientists and support staff flew five month-long missions over the Pacific Basin on the NSF/NCAR Gulfstream V, High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) aircraft between January 2009 and September 2011, spread throughout the annual cycle, from the surface to 14 km in altitude, and from 87°N to 67°S. Data from the HIPPO study of greenhouse gases and aerosols are now available to the atmospheric research community and the public. This comprehensive dataset provides the first high-resolution vertically resolved measurements of over 90 unique atmospheric species from nearly pole-to-pole over the Pacific Ocean across all seasons. The suite of atmospheric trace gases and aerosols is pertinent to understanding the carbon cycle and challenging global climate models. This dataset will provide opportunities for research across a broad spectrum of Earth sciences, including those analyzing the evolution in time and space of the greenhouse gases that affect global climate. The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) provides data management support for the HIPPO experiment including long-term data storage and dissemination. CDIAC has developed a relational database to house HIPPO merged 10-second meteorology, atmospheric chemistry, and aerosol data. This data set provides measurements from all Missions, 1 through 5, that took place from January of 2009 to September 2011. This presentation introduces newly build database and web interface, reflects the present state and functionality of the HIPPO Database and Exploration System as well as future plans for expansion and inclusion of combined discrete flask and GC sample GHG, Halocarbon, and hydrocarbon data.

  16. Access, responsibility, and funding: A systems thinking approach to universal access to oral health.

    PubMed

    Werhane, Patricia H

    2006-11-01

    Universal access to oral health care is a justifiable demand for a number of disparate but morally sound reasons. Nevertheless, that conclusion, however reached, has not solved the problem of the lack of access. Market forces, scarcity of funding, and lack of clarity as to who is responsible for ensuring that oral care is available seem to present insurmountable difficulties. I shall argue that these are not irresolvable problems, but the resolution has to take place through the tool of systems thinking and a systemic approach to moral imagination. Taking the lead from Susan Wolf's and Linda Emanuel's work on systems thinking, and developing ideas from work on mental models and moral imagination, I shall argue that what is often missing in discussions and demands for universal access to oral health care is a morally imaginative systemic approach that takes into account the multi-perspective dynamics involved in health care today. Moral imagination may encourage sound, broad-based, more inclusive moral thinking and moral judgment without ignoring the critical roles and responsibilities each of us has as professionals, providers, payers, or patients, without which change will not take place at all.

  17. Access, responsibility, and funding: A systems thinking approach to universal access to oral health.

    PubMed

    Werhane, Patricia H

    2006-11-01

    Universal access to oral health care is a justifiable demand for a number of disparate but morally sound reasons. Nevertheless, that conclusion, however reached, has not solved the problem of the lack of access. Market forces, scarcity of funding, and lack of clarity as to who is responsible for ensuring that oral care is available seem to present insurmountable difficulties. I shall argue that these are not irresolvable problems, but the resolution has to take place through the tool of systems thinking and a systemic approach to moral imagination. Taking the lead from Susan Wolf's and Linda Emanuel's work on systems thinking, and developing ideas from work on mental models and moral imagination, I shall argue that what is often missing in discussions and demands for universal access to oral health care is a morally imaginative systemic approach that takes into account the multi-perspective dynamics involved in health care today. Moral imagination may encourage sound, broad-based, more inclusive moral thinking and moral judgment without ignoring the critical roles and responsibilities each of us has as professionals, providers, payers, or patients, without which change will not take place at all. PMID:17106032

  18. Access 5 - Step 1: Human Systems Integration Program Plan (HSIPP)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This report describes the Human System Interface (HSI) analysis, design and test activities that will be performed to support the development of requirements and design guidelines to facilitate the incorporation of High Altitude Long Endurance (HALE) Remotely Operated Aircraft (ROA) at or above FL400 in the National Airspace System (NAS). These activities are required to support the design and development of safe, effective and reliable ROA operator and ATC interfaces. This plan focuses on the activities to be completed for Step 1 of the ACCESS 5 program. Updates to this document will be made for each of the four ACCESS 5 program steps.

  19. Access Control for Mobile Assessment Systems Using ID.

    PubMed

    Nakayama, Masaharu; Ishii, Tadashi; Morino, Kazuma

    2015-01-01

    The assessment of shelters during disaster is critical to ensure the health of evacuees and prevent pandemic. In the Ishinomaki area, one of the areas most damaged by the Great East Japan Earthquake, the highly organized assessment helped to successfully manage a total of 328 shelters with a total of 46,480 evacuees. The input and analysis of vast amounts of data was tedious work for staff members. However, a web-based assessment system that utilized mobile devices was thought to decrease workload and standardize the evaluation form. The necessary access of information should be controlled in order to maintain individuals' privacy. We successfully developed an access control system using IDs. By utilizing a unique numerical ID, users can access the input form or assessment table. This avoids unnecessary queries to the server, resulting in a quick response and easy availability, even with poor internet connection. PMID:26262204

  20. Evaluating the effectiveness of biometric access control systems

    NASA Astrophysics Data System (ADS)

    Lively, Valerie M.

    2005-05-01

    This paper describes the contribution by the National Safe Skies Alliance (Safe Skies) in operational testing of biometric access control systems under the guidance of the Transportation Security Administration (TSA). Safe Skies has been conducting operational tests of biometric access control systems on behalf of the TSA for approximately four years. The majority of this testing has occurred at the McGhee Tyson Airport (TYS) in Knoxville, Tennessee. Twelve separate biometric devices - eight fingerprint, facial, iris, hand geometry, and fingerprint and iris, have been tested to date. Tests were conducted at a TYS administrative door and different airports to evaluate the access control device under normal, abnormal, and attempt-to-defeat conditions.

  1. Access to medicines from a health system perspective

    PubMed Central

    Bigdeli, Maryam; Jacobs, Bart; Tomson, Goran; Laing, Richard; Ghaffar, Abdul; Dujardin, Bruno; Van Damme, Wim

    2013-01-01

    Most health system strengthening interventions ignore interconnections between systems components. In particular, complex relationships between medicines and health financing, human resources, health information and service delivery are not given sufficient consideration. As a consequence, populations' access to medicines (ATM) is addressed mainly through fragmented, often vertical approaches usually focusing on supply, unrelated to the wider issue of access to health services and interventions. The objective of this article is to embed ATM in a health system perspective. For this purpose, we perform a structured literature review: we examine existing ATM frameworks, review determinants of ATM and define at which level of the health system they are likely to occur; we analyse to which extent existing ATM frameworks take into account access constraints at different levels of the health system. Our findings suggest that ATM barriers are complex and interconnected as they occur at multiple levels of the health system. Existing ATM frameworks only partially address the full range of ATM barriers. We propose three essential paradigm shifts that take into account complex and dynamic relationships between medicines and other components of the health system. A holistic view of demand-side constraints in tandem with consideration of multiple and dynamic relationships between medicines and other health system resources should be applied; it should be recognized that determinants of ATM are rooted in national, regional and international contexts. These are schematized in a new framework proposing a health system perspective on ATM. PMID:23174879

  2. Inference by replication in densely connected systems

    SciTech Connect

    Neirotti, Juan P.; Saad, David

    2007-10-15

    An efficient Bayesian inference method for problems that can be mapped onto dense graphs is presented. The approach is based on message passing where messages are averaged over a large number of replicated variable systems exposed to the same evidential nodes. An assumption about the symmetry of the solutions is required for carrying out the averages; here we extend the previous derivation based on a replica-symmetric- (RS)-like structure to include a more complex one-step replica-symmetry-breaking-like (1RSB-like) ansatz. To demonstrate the potential of the approach it is employed for studying critical properties of the Ising linear perceptron and for multiuser detection in code division multiple access (CDMA) under different noise models. Results obtained under the RS assumption in the noncritical regime give rise to a highly efficient signal detection algorithm in the context of CDMA; while in the critical regime one observes a first-order transition line that ends in a continuous phase transition point. Finite size effects are also observed. While the 1RSB ansatz is not required for the original problems, it was applied to the CDMA signal detection problem with a more complex noise model that exhibits RSB behavior, resulting in an improvement in performance.

  3. Accessing and Sharing Data Using the CUAHSI Hydrologic Information System

    NASA Astrophysics Data System (ADS)

    Tarboton, D. G.; Horsburgh, J. S.; Whiteaker, T. L.; Maidment, D. R.; Zaslavsky, I.

    2008-12-01

    The Consortium of Universities for the Advancement of Hydrologic Science, Inc (CUAHSI) has a Hydrologic Information System (HIS) project, which is developing infrastructure to support the sharing of hydrologic data through web services and tools for data discovery, access and publication. Centralized data services support access to National Datasets such as the USGS National Water Information System (NWIS) and SNOTEL, in a standard way. Distributed data services allow users to establish their own server and publish their data through CUAHSI HIS web services. Once such a data service is registered within HIS Central, it becomes searchable and accessible through the centralized discovery and data access tools. The HIS is founded upon an information model for observations at stationary points that supports its data services. This is implemented as both XML and relational database schema for transmission and storage of data respectively. WaterML is the XML based data transmission model that underlies the machine to machine communications, while the Observations Data Model (ODM) is a relational database model for persistent data storage. Web services support access to hydrologic data stored in ODM and transmitted using WaterML directly from applications software such as Excel, MATLAB and ArcGIS that have Simple Object Access Protocol (SOAP) capability. A significant value of web services derives from the capability to use them from within a user's preferred analysis environment, rather than requiring a user to learn new software. This allows a user to work with data from national and academic sources, almost as though it was on their local disk. This poster will be computer-based with internet access for demonstration of HIS tools and functionality.

  4. A novel IPTV program multiplex access system to EPON

    NASA Astrophysics Data System (ADS)

    Xu, Xian; Liu, Deming; He, Wei; Lu, Xi

    2007-11-01

    With the rapid development of high speed networks, such as Ethernet Passive Optical Network (EPON), traffic patterns in access networks have evolved from traditional text-oriented service to the mixed text-, voice- and video- based services, leading to so called "Triple Play". For supporting IPTV service in EPON access network infrastructure, in this article we propose a novel IPTV program multiplex access system to EPON, which enables multiple IPTV program source servers to seamlessly access to IPTV service access port of optical line terminal (OLT) in EPON. There are two multiplex schemes, namely static multiplex scheme and dynamic multiplex scheme, in implementing the program multiplexing. Static multiplex scheme is to multiplex all the IPTV programs and forward them to the OLT, regardless of the need of end-users. While dynamic multiplex scheme can dynamically multiplex and forward IPTV programs according to what the end-users actually demand and those watched by no end-user would not be multiplexed. By comparing these two schemes, a reduced traffic of EPON can be achieved by using dynamic multiplex scheme, especially when most end-users are watching the same few IPTV programs. Both schemes are implemented in our system, with their hardware and software designs described.

  5. Public Access Online Library System (OLS) User's Guide.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Information Management and Services Div.

    How to access and search using the Online Library System (OLS) is described. The OLS is a computerized list of bibliographic citations compiled by the library network of the Environmental Protection Agency (EPA). It consists of several related databases and can be used by anyone to search for books, documents, journals, and other materials. In…

  6. 48 CFR 2452.239-70 - Access to HUD systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Fingerprint Check, and obtain a PIV Card prior to being permitted access to any such system in performance of..., “Questionnaire for Non-Sensitive Positions,” FD 258 (Fingerprint Chart), and a partial Optional Form (OF) 306... successfully cleared an FBI National Criminal History Fingerprint Check, and HUD has initiated the...

  7. 45 CFR 95.615 - Access to systems and records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION-GRANT PROGRAMS (PUBLIC ASSISTANCE, MEDICAL ASSISTANCE AND STATE CHILDREN'S HEALTH INSURANCE... (FFP) Specific Conditions for Ffp § 95.615 Access to systems and records. In accordance with 45 CFR..., including design developments, operation, and cost records of contractors and subcontractors at...

  8. Quantum Random Access Codes Using Single d-Level Systems.

    PubMed

    Tavakoli, Armin; Hameedi, Alley; Marques, Breno; Bourennane, Mohamed

    2015-05-01

    Random access codes (RACs) are used by a party to, with limited communication, access an arbitrary subset of information held by another party. Quantum resources are known to enable RACs that break classical limitations. Here, we study quantum and classical RACs with high-level communication. We derive average performances of classical RACs and present families of high-level quantum RACs. Our results show that high-level quantum systems can significantly increase the advantage of quantum RACs over their classical counterparts. We demonstrate our findings in an experimental realization of a quantum RAC with four-level communication.

  9. The ARAC client system: network-based access to ARAC

    SciTech Connect

    Leach, M J; Sumikawa, D; Webster, C

    1999-07-12

    The ARAC Client System allows users (such as emergency managers and first responders) with commonly available desktop and laptop computers to utilize the central ARAC system over the Internet or any other communications link using Internet protocols. Providing cost-effective fast access to the central ARAC system greatly expands the availability of the ARAC capability. The ARAC Client system consists of (1) local client applications running on the remote user's computer, and (2) ''site servers'' that provide secure access to selected central ARAC system capabilities and run on a scalable number of dedicated workstations residing at the central facility. The remote client applications allow users to describe a real or potential them-bio event, electronically sends this information to the central ARAC system which performs model calculations, and quickly receive and visualize the resulting graphical products. The site servers will support simultaneous access to ARAC capabilities by multiple users. The ARAC Client system is based on object-oriented client/server and distributed computing technologies using CORBA and Java, and consists of a large number of interacting components.

  10. Attacking the information access problem with expert systems

    NASA Technical Reports Server (NTRS)

    Ragusa, James M.; Orwig, Gary W.

    1991-01-01

    The results of applications research directed at finding an improved method of storing and accessing information are presented. Twelve microcomputer-based expert systems shells and five laser-optical formats have been studied, and the general and specific methods of interfacing these technologies are being tested in prototype systems. Shell features and interfacing capabilities are discussed, and results from the study of five laser-optical formats are recounted including the video laser, compact, and WORM disks, and laser cards and film. Interfacing, including laser disk device driver interfacing, is discussed and it is pointed out that in order to control the laser device from within the expert systems application, the expert systems shell must be able to access the device driver software. Potential integrated applications are investigated and an initial list is provided including consumer services, travel, law enforcement, human resources, marketing, and education and training.

  11. Does the public deserve free access to climate system science?

    NASA Astrophysics Data System (ADS)

    Grigorov, Ivo

    2010-05-01

    Some time ago it was the lack of public access to medical research data that really stirred the issue and gave inertia for legislation and a new publishing model that puts tax payer-funded medical research in the hands of those who fund it. In today's age global climate change has become the biggest socio-economic challenge, and the same argument resonates: climate affects us all and the publicly-funded science quantifying it should be freely accessible to all stakeholders beyond academic research. Over the last few years the ‘Open Access' movement to remove as much as possible subscription, and other on-campus barriers to academic research has rapidly gathered pace, but despite significant progress, the climate system sciences are not among the leaders in providing full access to their publications and data. Beyond the ethical argument, there are proven and tangible benefits for the next generation of climate researchers to adapt the way their output is published. Through the means provided by ‘open access', both data and ideas can gain more visibility, use and citations for the authors, but also result in a more rapid exchange of knowledge and ideas, and ultimately progress towards a sought solution. The presentation will aim to stimulate discussion and seek progress on the following questions: Should free access to climate research (& data) be mandatory? What are the career benefits of using ‘open access' for young scientists? What means and methods should, or could, be incorporated into current European graduate training programmes in climate research, and possible ways forward?

  12. Integration of access control and ancillary information systems

    SciTech Connect

    Rodriguez, J.R.; Ahrens, J.S.

    1995-07-01

    The DOE has identified the Lawrence Livermore National Laboratory ARGUS system as the standard entry control system for the DOE Complex. ARGUS integrates several key functions, specifically, badging, entry control, and verification of clearance status. Not all sites need or can afford an ARGUS system. Such sites are therefore limited to commercial equipment which provide ARGUS like features. In this project an alternative way to integrate commercial equipment into an integrated system to include badging, access control, property control, and automated verification of clearance status has been investigated. Such a system would provide smaller sites the same functionality as is provided by ARGUS. Further, it would allow sites to fully participate in the DOE`s concept of Complex wide access control. This multi-year task is comprised of three phases. Phase 1, system requirements and definitions, and phase 2, software and hardware development, were completed during fiscal year 1994. This report covers these two phases and the demonstration system which resulted. Phase three would employ the demonstration system to evaluate system performance, identify operational limits and to integrate additional features. The demonstration system includes a badging station, a database server, a managers workstation, an entry control system, and a property protection system. The functions have been integrated through the use of custom interfaces and operator screens which greatly increase ease of use.

  13. NASA Access Mechanism - Graphical user interface information retrieval system

    NASA Technical Reports Server (NTRS)

    Hunter, Judy F.; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited by factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  14. NASA access mechanism: Graphical user interface information retrieval system

    NASA Technical Reports Server (NTRS)

    Hunter, Judy; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited to factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  15. Personal Access Satellite System (PASS) study. Fiscal year 1989 results

    NASA Technical Reports Server (NTRS)

    Sue, Miles K. (Editor)

    1990-01-01

    The Jet Propulsion Laboratory is exploring the potential and feasibility of a personal access satellite system (PASS) that will offer the user greater freedom and mobility than existing or currently planned communications systems. Studies performed in prior years resulted in a strawman design and the identification of technologies that are critical to the successful implementation of PASS. The study efforts in FY-89 were directed towards alternative design options with the objective of either improving the system performance or alleviating the constraints on the user terminal. The various design options and system issues studied this year and the results of the study are presented.

  16. Improved CDMA Performance Using Parallel Interference Cancellation

    NASA Technical Reports Server (NTRS)

    Simon, Marvin; Divsalar, Dariush

    1995-01-01

    This report considers a general parallel interference cancellation scheme that significantly reduces the degradation effect of user interference but with a lesser implementation complexity than the maximum-likelihood technique. The scheme operates on the fact that parallel processing simultaneously removes from each user the interference produced by the remaining users accessing the channel in an amount proportional to their reliability. The parallel processing can be done in multiple stages. The proposed scheme uses tentative decision devices with different optimum thresholds at the multiple stages to produce the most reliably received data for generation and cancellation of user interference. The 1-stage interference cancellation is analyzed for three types of tentative decision devices, namely, hard, null zone, and soft decision, and two types of user power distribution, namely, equal and unequal powers. Simulation results are given for a multitude of different situations, in particular, those cases for which the analysis is too complex.

  17. Access control and privacy in large distributed systems

    NASA Technical Reports Server (NTRS)

    Leiner, B. M.; Bishop, M.

    1986-01-01

    Large scale distributed systems consists of workstations, mainframe computers, supercomputers and other types of servers, all connected by a computer network. These systems are being used in a variety of applications including the support of collaborative scientific research. In such an environment, issues of access control and privacy arise. Access control is required for several reasons, including the protection of sensitive resources and cost control. Privacy is also required for similar reasons, including the protection of a researcher's proprietary results. A possible architecture for integrating available computer and communications security technologies into a system that meet these requirements is described. This architecture is meant as a starting point for discussion, rather that the final answer.

  18. Accessing files in an Internet: The Jade file system

    NASA Technical Reports Server (NTRS)

    Peterson, Larry L.; Rao, Herman C.

    1991-01-01

    Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features.

  19. Accessing files in an internet - The Jade file system

    NASA Technical Reports Server (NTRS)

    Rao, Herman C.; Peterson, Larry L.

    1993-01-01

    Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features.

  20. Web-Accessible Scientific Workflow System for Performance Monitoring

    SciTech Connect

    Roelof Versteeg; Roelof Versteeg; Trevor Rowe

    2006-03-01

    We describe the design and implementation of a web accessible scientific workflow system for environmental monitoring. This workflow environment integrates distributed, automated data acquisition with server side data management and information visualization through flexible browser based data access tools. Component technologies include a rich browser-based client (using dynamic Javascript and HTML/CSS) for data selection, a back-end server which uses PHP for data processing, user management, and result delivery, and third party applications which are invoked by the back-end using webservices. This environment allows for reproducible, transparent result generation by a diverse user base. It has been implemented for several monitoring systems with different degrees of complexity.

  1. Type-Based Access Control in Data-Centric Systems

    NASA Astrophysics Data System (ADS)

    Caires, Luís; Pérez, Jorge A.; Seco, João Costa; Vieira, Hugo Torres; Ferrão, Lúcio

    Data-centric multi-user systems, such as web applications, require flexible yet fine-grained data security mechanisms. Such mechanisms are usually enforced by a specially crafted security layer, which adds extra complexity and often leads to error prone coding, easily causing severe security breaches. In this paper, we introduce a programming language approach for enforcing access control policies to data in data-centric programs by static typing. Our development is based on the general concept of refinement type, but extended so as to address realistic and challenging scenarios of permission-based data security, in which policies dynamically depend on the database state, and flexible combinations of column- and row-level protection of data are necessary. We state and prove soundness and safety of our type system, stating that well-typed programs never break the declared data access control policies.

  2. A semi-automated vascular access system for preclinical models

    NASA Astrophysics Data System (ADS)

    Berry-Pusey, B. N.; Chang, Y. C.; Prince, S. W.; Chu, K.; David, J.; Taschereau, R.; Silverman, R. W.; Williams, D.; Ladno, W.; Stout, D.; Tsao, T. C.; Chatziioannou, A.

    2013-08-01

    Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice.

  3. Interactive water monitoring system accessible by cordless telephone

    NASA Astrophysics Data System (ADS)

    Volpicelli, Richard; Andeweg, Pierre; Hagar, William G.

    1985-12-01

    A battery-operated, microcomputer-controlled monitoring device linked with a cordless telephone has been developed for remote measurements. This environmental sensor is self-contained and collects and processes data according to the information sent to its on-board computer system. An RCA model 1805 microprocessor forms the basic controller with a program encoded in memory for data acquisition and analysis. Signals from analog sensing devices used to monitor the environment are converted into digital signals and stored in random access memory of the microcomputer. This remote sensing system is linked to the laboratory by means of a cordless telephone whose base unit is connected to regular telephone lines. This offshore sensing system is simply accessed by a phone call originating from a computer terminal in the laboratory. Data acquisition is initiated upon request: Information continues to be processed and stored until the computer is reprogrammed by another phone call request. Information obtained may be recalled by a phone call after the desired environmental measurements are finished or while they are in progress. Data sampling parameters may be reset at any time, including in the middle of a measurement cycle. The range of the system is limited only by existing telephone grid systems and by the transmission characteristics of the cordless phone used as a communications link. This use of a cordless telephone, coupled with the on-board computer system, may be applied to other field studies requiring data transfer between an on-site analytical system and the laboratory.

  4. First Experiences Using XACML for Access Control in Distributed Systems

    NASA Technical Reports Server (NTRS)

    Lorch, Marcus; Proctor, Seth; Lepro, Rebekah; Kafura, Dennis; Shah, Sumit

    2003-01-01

    Authorization systems today are increasingly complex. They span domains of administration, rely on many different authentication sources, and manage permissions that can be as complex as the system itself. Worse still, while there are many standards that define authentication mechanisms, the standards that address authorization are less well defined and tend to work only within homogeneous systems. This paper presents XACML, a standard access control language, as one component of a distributed and inter-operable authorization framework. Several emerging systems which incorporate XACML are discussed. These discussions illustrate how authorization can be deployed in distributed, decentralized systems. Finally, some new and future topics are presented to show where this work is heading and how it will help connect the general components of an authorization system.

  5. ACCESS Earth: Promoting Accessibility to Earth System Science for Students with Disabilities

    NASA Astrophysics Data System (ADS)

    Locke, S. M.; Cohen, L.; Lightbody, N.

    2001-05-01

    ACCESS Earth is an intensive summer institute for high school students with disabilities and their teachers that is designed to encourage students with disabilities to consider careers in earth system science. Participants study earth system science concepts at a Maine coastal estuary, using Geographic Information Systems, remote sensing, and field observations to evaluate the impacts of climate change, sea level rise, and development on coastal systems. Teachers, students, and scientists work together to adapt field and laboratory activities for persons with disabilities, including those with mobility and visual impairments. Other sessions include demonstrations of assistive technology, career discussions, and opportunities for students to meet with successful scientists with disabilities from throughout the U.S. The summer institute is one of several programs in development at the University of Southern Maine to address the problem of underrepresentation of people with disabilities in the earth sciences. Other projects include a mentoring program for high school students, a web-based clearinghouse of resources for teaching earth sciences to students with disabilities, and guidebooks for adaptation of popular published earth system science curricula for disabled learners.

  6. Privacy and Access Control for IHE-Based Systems

    NASA Astrophysics Data System (ADS)

    Katt, Basel; Breu, Ruth; Hafner, Micahel; Schabetsberger, Thomas; Mair, Richard; Wozak, Florian

    Electronic Health Record (EHR) is the heart element of any e-health system, which aims at improving the quality and efficiency of healthcare through the use of information and communication technologies. The sensitivity of the data contained in the health record poses a great challenge to security. In this paper we propose a security architecture for EHR systems that are conform with IHE profiles. In this architecture we are tackling the problems of access control and privacy. Furthermore, a prototypical implementation of the proposed model is presented.

  7. Authorisation and access control for electronic health record systems.

    PubMed

    Blobel, Bernd

    2004-03-31

    Enabling the shared care paradigm, centralised or even decentralised electronic health record (EHR) systems increasingly become core applications in hospital information systems and health networks. For realising multipurpose use and reuse as well as inter-operability at knowledge level, EHR have to meet special architectural requirements. The component-oriented and model-based architecture should meet international standards. Especially in extended health networks realising inter-organisational communication and co-operation, authorisation cannot be organised at user level anymore. Therefore, models, methods and tools must be established to allow formal and structured policy definition, policy agreements, role definition, authorisation and access control. Based on the author's international engagement in EHR architecture and security standards referring to the revision of CEN ENV 13606, the GEHR/open EHR approach, HL7 and CORBA, models for health-specific and EHR-related roles, for authorisation management and access control have been developed. The basic concept is the separation of structural roles defining organisational entity-to-entity relationships and enabling specific acts on the one hand, and functional roles bound to specific activities and realising rights and duties on the other hand. Aggregation of organisational, functional, informational and technological components follows specific rules. Using UML and XML, the principles as well as some examples for analysis, design, implementation and maintenance of policy and authorisation management as well as access control have been practically implemented. PMID:15066555

  8. Authorisation and access control for electronic health record systems.

    PubMed

    Blobel, Bernd

    2004-03-31

    Enabling the shared care paradigm, centralised or even decentralised electronic health record (EHR) systems increasingly become core applications in hospital information systems and health networks. For realising multipurpose use and reuse as well as inter-operability at knowledge level, EHR have to meet special architectural requirements. The component-oriented and model-based architecture should meet international standards. Especially in extended health networks realising inter-organisational communication and co-operation, authorisation cannot be organised at user level anymore. Therefore, models, methods and tools must be established to allow formal and structured policy definition, policy agreements, role definition, authorisation and access control. Based on the author's international engagement in EHR architecture and security standards referring to the revision of CEN ENV 13606, the GEHR/open EHR approach, HL7 and CORBA, models for health-specific and EHR-related roles, for authorisation management and access control have been developed. The basic concept is the separation of structural roles defining organisational entity-to-entity relationships and enabling specific acts on the one hand, and functional roles bound to specific activities and realising rights and duties on the other hand. Aggregation of organisational, functional, informational and technological components follows specific rules. Using UML and XML, the principles as well as some examples for analysis, design, implementation and maintenance of policy and authorisation management as well as access control have been practically implemented.

  9. A Rewritable, Random-Access DNA-Based Storage System

    NASA Astrophysics Data System (ADS)

    Tabatabaei Yazdi, S. M. Hossein; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

    2015-09-01

    We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

  10. A Rewritable, Random-Access DNA-Based Storage System.

    PubMed

    Yazdi, S M Hossein Tabatabaei; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

    2015-01-01

    We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications. PMID:26382652

  11. A Rewritable, Random-Access DNA-Based Storage System.

    PubMed

    Yazdi, S M Hossein Tabatabaei; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

    2015-09-18

    We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

  12. Integration between terrestrial-based and satellite-based land mobile communications systems

    NASA Technical Reports Server (NTRS)

    Arcidiancono, Antonio

    1990-01-01

    A survey is given of several approaches to improving the performance and marketability of mobile satellite systems (MSS). The provision of voice/data services in the future regional European Land Mobile Satellite System (LMSS), network integration between the Digital Cellular Mobile System (GSM) and LMSS, the identification of critical areas for the implementation of integrated GSM/LMSS areas, space segment scenarios, LMSS for digital trunked private mobile radio (PMR) services, and code division multiple access (CDMA) techniques for a terrestrial/satellite system are covered.

  13. Patient-centred access to health care: conceptualising access at the interface of health systems and populations

    PubMed Central

    2013-01-01

    Background Access is central to the performance of health care systems around the world. However, access to health care remains a complex notion as exemplified in the variety of interpretations of the concept across authors. The aim of this paper is to suggest a conceptualisation of access to health care describing broad dimensions and determinants that integrate demand and supply-side-factors and enabling the operationalisation of access to health care all along the process of obtaining care and benefiting from the services. Methods A synthesis of the published literature on the conceptualisation of access has been performed. The most cited frameworks served as a basis to develop a revised conceptual framework. Results Here, we view access as the opportunity to identify healthcare needs, to seek healthcare services, to reach, to obtain or use health care services, and to actually have a need for services fulfilled. We conceptualise five dimensions of accessibility: 1) Approachability; 2) Acceptability; 3) Availability and accommodation; 4) Affordability; 5) Appropriateness. In this framework, five corresponding abilities of populations interact with the dimensions of accessibility to generate access. Five corollary dimensions of abilities include: 1) Ability to perceive; 2) Ability to seek; 3) Ability to reach; 4) Ability to pay; and 5) Ability to engage. Conclusions This paper explains the comprehensiveness and dynamic nature of this conceptualisation of access to care and identifies relevant determinants that can have an impact on access from a multilevel perspective where factors related to health systems, institutions, organisations and providers are considered with factors at the individual, household, community, and population levels. PMID:23496984

  14. A new watermarking approach based on combination of reversible watermarking and CDMA in spatial and DWT domain

    NASA Astrophysics Data System (ADS)

    Bekkouche, S.; Chouarfia, A.

    2011-06-01

    Image watermarking can be defined as a technique that allows insertion of imperceptible and indelible digital data into an image. In addition to its initial application which is the copyright, watermarking can be used in other fields, particularly in the medical field in order to contribute to secure images shared on the network for telemedicine applications. In this report we study some watermarking methods and the comparison result of their combination, the first one is based on the CDMA (Code Division Multiple Access) in DWT and spatial domain and its aim is to verify the image authenticity whereas the second one is the reversible watermarking (the least significant bits LSB and cryptography tools) and the reversible contrast mapping RCM its objective is to check the integrity of the image and to keep the Confidentiality of the patient data. A new scheme of watermarking is the combination of the reversible watermarking method based on LSB and cryptography tools and the method of CDMA in spatial and DWT domain to verify the three security properties Integrity, Authenticity and confidentiality of medical data and patient information .In the end ,we made a comparison between these methods within the parameters of quality of medical images. Initially, an in-depth study on the characteristics of medical images would contribute to improve these methods to mitigate their limits and to optimize the results. Tests were done on IRM kind of medical images and the quality measurements have been done on the watermarked image to verify that this technique does not lead to a wrong diagnostic. The robustness of the watermarked images against attacks has been verified on the parameters of PSNR, SNR, MSE and MAE which the experimental result demonstrated that the proposed algorithm is good and robust in DWT than in spatial domain.

  15. Pennsylvania Spatial Data Access and Online Advanced Spatial Information Systems

    NASA Astrophysics Data System (ADS)

    Lin, H.; Petersen, G.; Kelly, M.; Day, R.

    2002-05-01

    The Pennsylvania Spatial Data Access system (PASDA) is Pennsylvania's official geospatial information clearinghouse and the Commonwealth's node on the National Spatial Data Infrastructure. The PASDA clearinghouse provides for the widespread sharing of geospatial data, eliminates the creation of redundant data sets, and serves as a resource for locating data throughout the Commonwealth through its comprehensive standardized data storage, online free download, interactive mapping tools, and metadata/documentation efforts. PASDA also serves as a primary member of the Geography Network, a node of the National Biological Information Infrastructure for fisheries and aquatic resources, and provides several WebGIS applications such as Pennsylvania Explorer and Pennsylvania Interactive Watershed Atlas. With PASDA data delivery and access mechanisms in place, we are further building Online Advanced Spatial Information Systems (OASIS) for 1) geospatial data mining and knowledge discovery and 2) intelligent spatial decision support. The OASIS intends to integrate artificial intelligence, spatial modeling, data mining tools, and expert systems into PASDA so that a mechanism for transforming geospatial data into information, synthesizing geospatial knowledge, and supporting spatial decision-making may be developed.

  16. DS-CDMA with predetection diversity for indoor radio communications

    NASA Astrophysics Data System (ADS)

    Wang, Jiangzhou; Moeneclaey, Marc; Milstein, Laurence B.

    1994-02-01

    This paper investigates the average bit error rate performance of a direct sequence code division multiple access system operating over a multipath Rician fading channel. We consider both phase-shift-keying modulation with coherent demodulation and differential phase-shift-keying modulation with noncoherent demodulation. Predetection multipath diversity (equal gain combining) is considered for improving the BER performance.

  17. Electrical impedance tomography system: an open access circuit design

    PubMed Central

    Soleimani, Manuchehr

    2006-01-01

    Background This paper reports a simple 2-D system for electrical impedance tomography EIT, which works efficiently and is low cost. The system has been developed in the Sharif University of Technology Tehran-Iran (for the author's MSc Project). Methods The EIT system consists of a PC in which an I/O card is installed with an external current generator, a multiplexer, a power supply and a phantom with an array of electrodes. The measurement system provides 12-bit accuracy and hence, suitable data acquisition software has been prepared accordingly. The synchronous phase detection method has been implemented for voltage measurement. Different methods of image reconstruction have been used with this instrument to generate electrical conductivity images. Results The results of simulation and real measurement of the system are presented. The reconstruction programs were written in MATLAB and the data acquisition software in C++. The system has been tested with both static and dynamic mode in a 2-D domain. Better results have been produced in the dynamic mode of operation, due to the cancellation of errors. Conclusion In the spirit of open access publication the design details of this simple EIT system are made available here. PMID:16672061

  18. Computer network access to scientific information systems for minority universities

    NASA Astrophysics Data System (ADS)

    Thomas, Valerie L.; Wakim, Nagi T.

    1993-08-01

    The evolution of computer networking technology has lead to the establishment of a massive networking infrastructure which interconnects various types of computing resources at many government, academic, and corporate institutions. A large segment of this infrastructure has been developed to facilitate information exchange and resource sharing within the scientific community. The National Aeronautics and Space Administration (NASA) supports both the development and the application of computer networks which provide its community with access to many valuable multi-disciplinary scientific information systems and on-line databases. Recognizing the need to extend the benefits of this advanced networking technology to the under-represented community, the National Space Science Data Center (NSSDC) in the Space Data and Computing Division at the Goddard Space Flight Center has developed the Minority University-Space Interdisciplinary Network (MU-SPIN) Program: a major networking and education initiative for Historically Black Colleges and Universities (HBCUs) and Minority Universities (MUs). In this paper, we will briefly explain the various components of the MU-SPIN Program while highlighting how, by providing access to scientific information systems and on-line data, it promotes a higher level of collaboration among faculty and students and NASA scientists.

  19. 76 FR 60398 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... Prohibition on Circumvention of Copyright Protection Systems for Access Control Technologies, 68 FR 62011... Circumvention of Copyright Protection Systems for Access Control Technologies, 71 FR 68472, 68480, published in... Protection Systems for Access Control Technologies, 65 FR 64556, 64564, published in the Federal...

  20. Introduction to the Personal Access Satellite System Study

    NASA Technical Reports Server (NTRS)

    Sue, Miles K.

    1990-01-01

    A recent study by the National Telecommunications and Information Administration (NTIA) has concluded that the 21st century will be the age of information in which the telecommunication infrastructure will be vital to the social and economic well being of society. To meet the challenge of the coming age, JPL has been performing studies on a personal access satellite system (PASS) for the 21st century. The PASS study can be traced back to a study in which the technical feasibility and potential applications of a high frequency, low data rate satellite system were identified using small fixed terminals. Herein, the PASS concept is described along with the strawman design. Then the key challenges are identified along with possible solutions. Finally, the plan for the future is summarized from the key results.

  1. Spacelab system analysis: The modified free access protocol: An access protocol for communication systems with periodic and Poisson traffic

    NASA Technical Reports Server (NTRS)

    Ingels, Frank; Owens, John; Daniel, Steven

    1989-01-01

    The protocol definition and terminal hardware for the modified free access protocol, a communications protocol similar to Ethernet, are developed. A MFA protocol simulator and a CSMA/CD math model are also developed. The protocol is tailored to communication systems where the total traffic may be divided into scheduled traffic and Poisson traffic. The scheduled traffic should occur on a periodic basis but may occur after a given event such as a request for data from a large number of stations. The Poisson traffic will include alarms and other random traffic. The purpose of the protocol is to guarantee that scheduled packets will be delivered without collision. This is required in many control and data collection systems. The protocol uses standard Ethernet hardware and software requiring minimum modifications to an existing system. The modification to the protocol only affects the Ethernet transmission privileges and does not effect the Ethernet receiver.

  2. Safety systems and access control in the National Ignition Facility.

    PubMed

    Reed, Robert K; Bell, Jayce C

    2013-06-01

    The National Ignition Facility (NIF) is the world's largest and most energetic laser system. The facility has the potential to generate ionizing radiation due to the interaction between the laser beams and target material, with neutrons and gamma rays being produced during deuterium-tritium fusion reactions. To perform these experiments, several types of hazards must be mitigated and controlled to ensure personnel safety. NIF uses a real-time safety system to monitor and mitigate the hazards presented by the facility. The NIF facility Safety Interlock System (SIS) monitors for oxygen deficiency and controls access to the facility preventing exposure to laser light and radiation from the Radiation Generating Devices. It also interfaces to radiation monitoring and other radiological monitoring and alarm systems. The SIS controls permissives to the hazard-generating equipment and annunciates hazard levels in the facility. To do this reliably and safely, the SIS has been designed as a fail-safe system with a proven performance record now spanning over 10 y. This paper discusses the SIS, its design, implementation, operator interfaces, validation/verification, and the hazard mitigation approaches employed in the NIF. A brief discussion of the Failure Modes and Effect Analysis supporting the SIS will also be presented. The paper ends with a general discussion of SIS do's and don'ts and common design flaws that should be avoided in SIS design. PMID:23629061

  3. Bureau of Prisons access control system: functional and operational requirements

    NASA Astrophysics Data System (ADS)

    Janus, Michael; Carlson, Peter M.; Kane, Thomas

    1997-01-01

    The Federal Bureau of Prisons (BOP) operates 86 correctional institutions nationwide. The BOP has grown dramatically, the size of its inmate population growing from just over 41,000 inmates in 1987 to over 100,000 today. The number of BOP staff managing these facilities has grown correspondingly, more than doubling in number in the same ten year period. Technology has paid a major role in keeping up with this growth while maintaining high standards of security in BOP institutions. In an attempt to further enhance security in its institutions, the BOP has recently begun pilot testing an access control and entry system (ACES). ACES is intended to provide an automated record of very entry and exit to a correctional institution. ACES takes advantage of several methods of identifying an individual (inmate, staff or visitor) to assure that the individual exiting the institution is the same as the individual entering. The pilot test has raised a number of questions regarding the implementation of a technologically sophisticated system in a correctional institution. Questions of training, support, 'ownership,' cost effectiveness, and future potential all influence the deployment of this system. Preliminary results indicate that an adequate training and support system is essential to the performance of any sophisticated system and that other organizational issues need to be addressed before the decision to implement is made.

  4. Title III Evaluation for the Access Road System

    SciTech Connect

    H.R. Montalv

    1998-07-28

    The objective of this evaluation is to provide recommendations to ensure consistency between the technical baseline requirements, baseline design, and the as-constructed Access Roads. Recommendations for resolving discrepancies between the as-constructed system, the technical baseline requirements, and the baseline design are included in this report. Cost and Schedule estimates are provided for all recommended modifications. This report does not address items which do not meet current safety or code requirements. These items are identified to the CMO and immediate action is taken to correct the situation. The report does identify safety and code items for which the A/E is recommending improvements. The recommended improvements will exceed the minimum requirements of applicable code and safety guide lines. These recommendations are intended to improve and enhance the operation and maintenance of the facility.

  5. The Nimbus F Random Access Measurement System /RAMS/

    NASA Technical Reports Server (NTRS)

    Coates, J. L.

    1975-01-01

    In 1974, the Random Access Measurement System (RAMS) will be launched aboard the Nimbus F satellite as part of the Tropical Wind, Energy Conversion, and Reference Level Experiment (TWERLE). This paper describes operation and performance of the RAMS instrument, which will provide a means of tracking and collecting data from a large number of instrumented platforms. In operation, the RAMS will perform satellite onboard processing of up to eight simultaneous platform transmissions, following search and detection of the randomly received platform transmissions in a compressed-time expanded-frequency domain. The processed data is stored aboard the satellite for readout every 108 minutes (orbital period), and platform locational coordinates and/or velocity components are determined in a central ground data processing facility.

  6. LAPAROSCOPIC SALPINGECTOMY IN TWO CAPTIVE LEOPARDS (PANTHERA PARDUS) USING A SINGLE PORTAL ACCESS SYSTEM.

    PubMed

    Hartman, Marthinus J; Monnet, Eric; Kirberger, Robert M; Schoeman, Johan P

    2015-12-01

    Laparoscopic salpingectomy was performed in two adult leopards (Panthera pardus) using a single portal access system, with a multicannulated single-incision laparoscopic surgery port, without any complications. The poorly developed ovarian bursa provided easy access to the uterine tube for salpingectomy. Laparoscopic salpingectomy can be safely performed in the leopard using a single portal access system.

  7. LAPAROSCOPIC SALPINGECTOMY IN TWO CAPTIVE LEOPARDS (PANTHERA PARDUS) USING A SINGLE PORTAL ACCESS SYSTEM.

    PubMed

    Hartman, Marthinus J; Monnet, Eric; Kirberger, Robert M; Schoeman, Johan P

    2015-12-01

    Laparoscopic salpingectomy was performed in two adult leopards (Panthera pardus) using a single portal access system, with a multicannulated single-incision laparoscopic surgery port, without any complications. The poorly developed ovarian bursa provided easy access to the uterine tube for salpingectomy. Laparoscopic salpingectomy can be safely performed in the leopard using a single portal access system. PMID:26667558

  8. 77 FR 64838 - Sixteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-23

    ... Federal Aviation Administration Sixteenth Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held November 15,...

  9. 78 FR 16757 - Twentieth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-18

    ... Federal Aviation Administration Twentieth Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held April 4, 2013 from...

  10. 77 FR 55894 - Fifteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... Federal Aviation Administration Fifteenth Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held September 27-28,...

  11. 77 FR 15448 - Twelfth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Notice of meeting RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... 224, Airport Security Access Control Systems DATES: The meeting will be held April 5, 2012, from 10...

  12. 78 FR 22025 - Twenty First Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... Federal Aviation Administration Twenty First Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held April 9-10,...

  13. 78 FR 43963 - Twenty-Third Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... Federal Aviation Administration Twenty-Third Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on June 20,...

  14. 77 FR 71474 - Seventeenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-30

    ... Federal Aviation Administration Seventeenth Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held December 13,...

  15. 77 FR 2343 - Eleventh Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... Federal Aviation Administration Eleventh Meeting: RTCA Special Committee 224, Airport Security Access...). ACTION: Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY: The FAA..., Airport Security Access Control Systems. DATES: The meeting will be held February 9, 2012, from 10...

  16. A New Aloha Anti-Collision Algorithm Based on CDMA

    NASA Astrophysics Data System (ADS)

    Bai, Enjian; Feng, Zhu

    The tags' collision is a common problem in RFID (radio frequency identification) system. The problem has affected the integrity of the data transmission during the process of communication in the RFID system. Based on analysis of the existing anti-collision algorithm, a novel anti-collision algorithm is presented. The new algorithm combines the group dynamic frame slotted Aloha algorithm with code division multiple access technology. The algorithm can effectively reduce the collision probability between tags. Under the same number of tags, the algorithm is effective in reducing the reader recognition time and improve overall system throughput rate.

  17. McIDAS III - A modern interactive data access and analysis system. [Man computer Interactive Data Access System

    NASA Technical Reports Server (NTRS)

    Suomi, V. E.; Fox, R.; Limaye, S. S.; Smith, W. L.

    1983-01-01

    A powerful facility for meteorological analysis called the Man Computer Interactive Data Access System (McIDAS) was designed and implemented in the early 1970's at the Space Science and Engineering Center of the University of Wisconsin-Madison. Hardware and software experience gained via extensive use of that facility and its derivatives have led to a newer implementation of McIDAS on a larger computer with significant enhancements to the supporting McIDAS software. McIDAS allows remote and local access to a wide range of data from satellites and conventional observations, time lapse displays of imagery data, overlaid graphics, and current and past meteorological data. Available software allows one to perform analysis of a wide range of digital images as well as temperature and moisture sounding data obtained from satellites. McIDAS can generate multicolor composites of conventional and satellite weather data, radar and forecast data in a wide variety of two- and three-dimensional displays as well as time lapse movies of these analyses. These and other capabilities are described in this paper.

  18. "An On-Line Access System for TRMM Data"

    NASA Technical Reports Server (NTRS)

    Rui, Hualan

    1999-01-01

    The Tropical Rainfall Measuring Mission (TRMM), jointly sponsored by the National Aeronautics and Space Administration (NASA) of United States and the National Space Development Agency (NASDA) of Japan, provides visible, infrared, and microwave observations of tropical and subtropical rain system. The satellite observations are complemented by ground radar and rain gauge measurements to validate satellite rain estimation techniques. TRMM satellite was launched on November 27, 1997(EST). Data from TRMM are being archived, processed, and disseminated by DAAC at the Goddard Space Flight Center (GSFC) of NASA. The Goddard DAAC has been archiving Tropical Rainfall Measuring Mission (TRMM) data since the launch. The TRMM level 1 and level 2 products first have been released to public on June 15, 1998. Now, most of TRMM products, including some ground validation products are released to public. TRMM data are useful for forecast model research, disaster mitigation, climatological studies, agricultural predictions, and many other applications. An online system or user interface is designed for easy, friendly, and quick display, access, and ordering of the TRMM data. Components, features, and limitations of the system will be discussed and demonstrated. The TRMM standard products and variety of the subsets and ancillary data will be shown, and their availability will be discussed.

  19. Power System Trade Studies for the Lunar Surface Access Module

    NASA Technical Reports Server (NTRS)

    Kohout, Lisa, L.

    2008-01-01

    A Lunar Lander Preparatory Study (LLPS) was undertaken for NASA's Lunar Lander Pre-Project in 2006 to explore a wide breadth of conceptual lunar lander designs. Civil servant teams from nearly every NASA center responded with dozens of innovative designs that addressed one or more specific lander technical challenges. Although none of the conceptual lander designs sought to solve every technical design issue, each added significantly to the technical database available to the Lunar Lander Project Office as it began operations in 2007. As part of the LLPS, a first order analysis was performed to identify candidate power systems for the ascent and descent stages of the Lunar Surface Access Module (LSAM). A power profile by mission phase was established based on LSAM subsystem power requirements. Using this power profile, battery and fuel cell systems were modeled to determine overall mass and volume. Fuel cell systems were chosen for both the descent and ascent stages due to their low mass. While fuel cells looked promising based on these initial results, several areas have been identified for further investigation in subsequent studies, including the identification and incorporation of peak power requirements into the analysis, refinement of the fuel cell models to improve fidelity and incorporate ongoing technology developments, and broadening the study to include solar power.

  20. Advanced Propulsion Systems for Low-Cost Access to Space

    NASA Technical Reports Server (NTRS)

    Whitlow, Woodrow, Jr.

    2004-01-01

    NASA's Space Access Goal Ensure the provision of space access and improve it by increasing safety, reliability, and affordability. (1) The launch phase continues to be the highest risk period of any space mission. (2) Launch costs remain an obstacle to the complete utilization of space for research, exploration, and commercial purposes (3) Improving the Nation's access to space through the application of new technology is one of NASA's primary roles.

  1. "What Page, Miss?" Enhancing Text Accessibility with DAISY (Digital Accessible Information SYstem)

    ERIC Educational Resources Information Center

    Spooner, Sue

    2014-01-01

    Introduction: The provision of specially formatted materials is a complex and increasingly difficult task, given the extensive and burgeoning range of texts and resources available for classroom use. The need to extend the provision of accessible formats to include digital resources (in addition to braille, audio, and large print) led to a study…

  2. NuDat system for access to nuclear data

    SciTech Connect

    Dunford, C.L.; Kinsey, R.R.

    1998-07-07

    The NuDat program provides a user with access to nuclear properties and to some nuclear reaction data. The program operates on DEC VMS operating systems and on PC`s with Microsoft operating systems. The program has four user interfaces, all having the same content and functionality. These interfaces are Web, Video and Sequential for VMS. The PC interface is identical to the VMS Video interface. Forms are used to supply the type of data the user desires, the retrieval parameters, the output format, and the sort order of the data. The program and associated database is used in basic research, particularly for the systematic study of nuclear properties. It is also a useful tool for applied research to identify radiations from radionuclides contained in environmental samples, or from those produced by neutron or charged particle activation. The NuDat database is derived from several databases maintained by the National Nuclear Data Center. The databases are the Adopted Levels and Gammas data sets from ENSDF, the Nuclear Wallet Cards, Decay Radiations derived from ENSDF decay data sets processed by RADLIST, and Thermal Neutron Cross Sections.

  3. Access to Sign Language Interpreters in the Criminal Justice System.

    ERIC Educational Resources Information Center

    Miller, Katrina R.

    2001-01-01

    This study surveyed 46 professional sign language interpreters working in criminal justice settings and evaluated 22 cases to evaluate access issues for individuals with hearing impairments. Recommendations to increase the accessibility of interpreting services included providing ongoing awareness training to criminal justice personnel and…

  4. Single port access surgery with a novel Port Camera system.

    PubMed

    Terry, Benjamin S; Schoen, Jonathan; Mills, Zachary; Rentschler, Mark E

    2012-06-01

    In this work, the authors designed, built, and tested a novel port camera system for single port access (SPA) laparoscopic surgery. This SPA Port Camera device integrates the monitor, laparoscopic camera, and light source into an inexpensive, portable cannula port. The device uses a 2-channel SPA port inserted through an umbilical incision, similar to traditional SPA. After insertion into a channel, the device deploys a small camera module and LED lamp in vivo. An integrated, on-patient LCD provides the view of the surgical site. The design intent of the port camera is to enhance SPA by (a) reducing the size of the SPA port through the elimination of the dedicated laparoscope channel; (b) reducing equipment cost by integrating an inexpensive CMOS sensor and LED lamp at the port tip; (c) eliminating the need for an assistant who operates the laparoscope; and (d) mechanically coupling the camera, tool port, and on-patient LCD screen. The effectiveness of the device was evaluated by comparing the video performance with a leading industry laparoscope and by performing a user evaluation study and live porcine surgery with the device. Effectiveness of the device was mixed. Overall video system performance of the device is better than an industry standard high-definition laparoscope, implying that significant cost savings over a traditional system are possible. Participant study results suggest that simulated laparoscopic tasks are as efficient with the SPA Port Camera as they are with a typical SPA configuration. However, live surgery revealed several shortcomings of the SPA Port Camera.

  5. 75 FR 61819 - First Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ... Federal Aviation Administration First Meeting: RTCA Special Committee 224: Airport Security Access Control... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access...

  6. 76 FR 59481 - Ninth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... TRANSPORTATION Federal Aviation Administration Ninth Meeting: RTCA Special Committee 224: Airport Security Access... Committee 224 meeting: Airport Security Access Control Systems. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control...

  7. 76 FR 9632 - Fifth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ... Federal Aviation Administration Fifth Meeting: RTCA Special Committee 224: Airport Security Access Control... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access...

  8. 75 FR 80886 - Third Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... Federal Aviation Administration Third Meeting: RTCA Special Committee 224: Airport Security Access Control... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access...

  9. 76 FR 16470 - Sixth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... Federal Aviation Administration Sixth Meeting: RTCA Special Committee 224: Airport Security Access Control... meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access...

  10. A Framework for Context Sensitive Risk-Based Access Control in Medical Information Systems.

    PubMed

    Choi, Donghee; Kim, Dohoon; Park, Seog

    2015-01-01

    Since the access control environment has changed and the threat of insider information leakage has come to the fore, studies on risk-based access control models that decide access permissions dynamically have been conducted vigorously. Medical information systems should protect sensitive data such as medical information from insider threat and enable dynamic access control depending on the context such as life-threatening emergencies. In this paper, we suggest an approach and framework for context sensitive risk-based access control suitable for medical information systems. This approach categorizes context information, estimating and applying risk through context- and treatment-based permission profiling and specifications by expanding the eXtensible Access Control Markup Language (XACML) to apply risk. The proposed framework supports quick responses to medical situations and prevents unnecessary insider data access through dynamic access authorization decisions in accordance with the severity of the context and treatment. PMID:26075013

  11. A Framework for Context Sensitive Risk-Based Access Control in Medical Information Systems

    PubMed Central

    Choi, Donghee; Kim, Dohoon; Park, Seog

    2015-01-01

    Since the access control environment has changed and the threat of insider information leakage has come to the fore, studies on risk-based access control models that decide access permissions dynamically have been conducted vigorously. Medical information systems should protect sensitive data such as medical information from insider threat and enable dynamic access control depending on the context such as life-threatening emergencies. In this paper, we suggest an approach and framework for context sensitive risk-based access control suitable for medical information systems. This approach categorizes context information, estimating and applying risk through context- and treatment-based permission profiling and specifications by expanding the eXtensible Access Control Markup Language (XACML) to apply risk. The proposed framework supports quick responses to medical situations and prevents unnecessary insider data access through dynamic access authorization decisions in accordance with the severity of the context and treatment. PMID:26075013

  12. A selection system for identifying accessible sites in target RNAs.

    PubMed Central

    Pan, W H; Devlin, H F; Kelley, C; Isom, H C; Clawson, G A

    2001-01-01

    Although ribozymes offer tremendous potential for posttranscriptionally controlling expression of targeted genes, their utility is often limited by the accessibility of the targeted regions within the RNA transcripts. Here we describe a method that identifies RNA regions that are accessible to oligonucleotides. Based on this selection protocol, we show that construction of hammerhead ribozymes targeted to the identified regions results in catalytic activities that are consistently and substantially greater than those of ribozymes designed on the basis of computer modeling. Identification of accessible sites should also be widely applicable to design of antisense oligonucleotides and DNAzymes. PMID:11345439

  13. Electromagnetic Sensor-Guided Enteral Access Systems: A Literature Review.

    PubMed

    Smithard, David; Barrett, Nicholas A; Hargroves, David; Elliot, Stuart

    2015-06-01

    Enteral feeding is the nutritional support of choice for acutely ill patients with functional gastrointestinal tracts who are unable to swallow. Several benefits including reduced mortality and length of hospital stay have been associated with early initiation of enteral feeding. However, misplacement of conventional nasoenteric tubes is relatively common and can result in complications including pneumothorax. In addition, the need to confirm the position by X-ray can delay the start of using the tube. Eliminating these delays can help patients start feeding, and minimise the adverse impact on initiating hydration and medication. The purpose of this review was to critically examine whether electromagnetic sensor-guided enteral access systems (EMS-EAS) can help overcome the challenges of conventional nasoenteric feeding tube placement and confirmation. The Royal Society of Medicine's library performed two searches on Medline (1946-March 2014) and Embase (1947-March 2014) covering all papers on Cortrak or electromagnetic or magnetic guidance systems for feeding tubes in adults. Results from the literature search found an agreement between the radiographic and EMS-EAS confirmation of placement. EMS-EAS virtually eliminated the risk of misplacement and pneumothorax was not reported. In addition, studies showed a small decrease in the number of X-rays with EMS-EAS and a reduced average time to start feeding compared with blind placement. This review suggests that EMS-EAS reduces several complications associated with the misplacement of nasoenteric feeding tubes, and that there could be considerable improvements in mortality, morbidity, patient experience and cost if EMS-EAS is used instead of conventional methods.

  14. MIAPS: a web-based system for remotely accessing and presenting medical images.

    PubMed

    Shen, Hualei; Ma, Dianfu; Zhao, Yongwang; Sun, Hailong; Sun, Sujun; Ye, Rongwei; Huang, Lei; Lang, Bo; Sun, Yan

    2014-01-01

    MIAPS (medical image access and presentation system) is a web-based system designed for remotely accessing and presenting DICOM image. MIAPS is accessed with web browser through the Internet. MIAPS provides four features: DICOM image retrieval, maintenance, presentation and output. MIAPS does not intent to replace sophisticated commercial and open source packages, but it provides a web-based solution for teleradiology and medical image sharing. The system has been evaluated by 39 hospitals in China for 10 months.

  15. Demonstration of end-to-end cloud-DSL with a PON-based fronthaul supporting 5.76-Gb/s throughput with 48 eCDMA-encoded 1024-QAM discrete multi-tone signals.

    PubMed

    Fang, Liming; Zhou, Lei; Liu, Xiang; Zhang, Xiaofeng; Sui, Meng; Effenberger, Frank; Zhou, Jun

    2015-05-18

    We experimentally demonstrate an end-to-end ultra-broadband cloud-DSL network using passive optical network (PON) based fronthaul with electronic code-division-multiple-access (eCDMA) encoding and decoding. Forty-eight signals that are compliant with the very-high-bit-rate digital subscriber line 2 (VDSL2) standard are transmitted with a record throughput of 5.76 Gb/s over a hybrid link consisting of a 20-km standard single-mode fiber and a 100-m twisted pair.

  16. Computer Interfaces for User Access to Heterogeneous Information-Retrieval Systems.

    ERIC Educational Resources Information Center

    Marcus, Richard S.; Reintjes, J. Francis

    A translating-computer-interface approach to providing a common, or virtual-system, mode of access to a network of heterogeneous online bibliographic retrieval systems has been investigated. Enhanced access to such systems by end users has been demonstrated through test usage of an experimental interface. A table-driven, rule-based message…

  17. 42 CFR 431.834 - Access to records: Claims processing assessment systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION Quality Control Medicaid Quality Control (mqc) Claims Processing Assessment System § 431.834 Access to records: Claims processing assessment systems. The agency, upon written request, must provide HHS staff with access to all records pertaining to its MQC claims processing assessment system...

  18. 78 FR 31627 - Twenty-Second Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on June 20,...

  19. 78 FR 7850 - Nineteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY... Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held February 21,...

  20. 42 CFR 431.834 - Access to records: Claims processing assessment systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION Quality Control Medicaid Quality Control (mqc) Claims Processing Assessment System § 431.834 Access to records: Claims processing assessment systems. The agency, upon written request, must provide HHS staff with access to all records pertaining to its MQC claims processing assessment system...

  1. 42 CFR 431.834 - Access to records: Claims processing assessment systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION Quality Control Medicaid Quality Control (mqc) Claims Processing Assessment System § 431.834 Access to records: Claims processing assessment systems. The agency, upon written request, must provide HHS staff with access to all records pertaining to its MQC claims processing assessment system...

  2. Access, Retention and Progression of Black Students Through the Two-Tier Florida Higher Education System.

    ERIC Educational Resources Information Center

    Grigg, Charles M.

    This study addresses the question of whether a State system of higher education based on different tiers (a community college system and a State university system) provides equal access and opportunity for minority students. Specifically, the study investigates access distribution, retention, and progression of minority students using Florida…

  3. From System Expansion to System Contraction: Access to Higher Education in Poland

    ERIC Educational Resources Information Center

    Kwiek, Marek

    2013-01-01

    Access to higher education in Poland is changing due to the demography of smaller cohorts of potential students. Following a demand-driven educational expansion after the collapse of communism in 1989, the higher education system is now contracting. Such expansion/contraction and growth/decline in European higher education has rarely been…

  4. 40 CFR 264.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Access to communications or alarm system. 264.34 Section 264.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  5. 40 CFR 264.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Access to communications or alarm system. 264.34 Section 264.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  6. 40 CFR 264.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Access to communications or alarm system. 264.34 Section 264.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  7. 40 CFR 264.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Access to communications or alarm system. 264.34 Section 264.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  8. 40 CFR 264.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Access to communications or alarm system. 264.34 Section 264.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)...

  9. Extending Virtual Access: Promoting Engagement and Retention through Integrated Support Systems

    ERIC Educational Resources Information Center

    McCracken, Holly

    2004-01-01

    "Extending Virtual Access: Promoting Engagement and Retention through Integrated Support Systems" focuses upon expanding the scope of on-line instructional delivery to include academic support systems critical to ensuring that virtual learning environments are inclusive, accessible, instructive, and responsive to changing student needs.…

  10. 28 CFR 16.88 - Exemption of Antitrust Division Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Antitrust Division Systems-limited access. 16.88 Section 16.88 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... Antitrust Division Systems—limited access. (a) The following system of records is exempt from 5 U.S.C....

  11. 28 CFR 16.74 - Exemption of National Security Division Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of National Security Division Systems-limited access. 16.74 Section 16.74 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR... National Security Division Systems—limited access. (a) The following system of records is exempted...

  12. 5 CFR 293.504 - Composition of, and access to, the Employee Medical File System.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Composition of, and access to, the Employee Medical File System. 293.504 Section 293.504 Administrative Personnel OFFICE OF PERSONNEL... Composition of, and access to, the Employee Medical File System. (a) All employee occupational medical...

  13. 5 CFR 293.504 - Composition of, and access to, the Employee Medical File System.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Composition of, and access to, the Employee Medical File System. 293.504 Section 293.504 Administrative Personnel OFFICE OF PERSONNEL... Composition of, and access to, the Employee Medical File System. (a) All employee occupational medical...

  14. 5 CFR 293.504 - Composition of, and access to, the Employee Medical File System.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Composition of, and access to, the Employee Medical File System. 293.504 Section 293.504 Administrative Personnel OFFICE OF PERSONNEL... Composition of, and access to, the Employee Medical File System. (a) All employee occupational medical...

  15. 21 CFR 21.65 - Access to records in exempt systems.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Access to records in exempt systems. 21.65 Section 21.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROTECTION OF PRIVACY Exemptions § 21.65 Access to records in exempt systems. (a) Where a Privacy Act...

  16. 21 CFR 21.65 - Access to records in exempt systems.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Access to records in exempt systems. 21.65 Section 21.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROTECTION OF PRIVACY Exemptions § 21.65 Access to records in exempt systems. (a) Where a Privacy Act...

  17. 21 CFR 21.65 - Access to records in exempt systems.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Access to records in exempt systems. 21.65 Section 21.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROTECTION OF PRIVACY Exemptions § 21.65 Access to records in exempt systems. (a) Where a Privacy Act...

  18. 21 CFR 21.65 - Access to records in exempt systems.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Access to records in exempt systems. 21.65 Section 21.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROTECTION OF PRIVACY Exemptions § 21.65 Access to records in exempt systems. (a) Where a Privacy Act...

  19. 21 CFR 21.65 - Access to records in exempt systems.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Access to records in exempt systems. 21.65 Section 21.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROTECTION OF PRIVACY Exemptions § 21.65 Access to records in exempt systems. (a) Where a Privacy Act...

  20. 77 FR 25525 - Thirteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... TRANSPORTATION Federal Aviation Administration Thirteenth Meeting: RTCA Special Committee 224, Airport Security... (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held May 30, 2012, from...

  1. Fine-Grained Access Control for Electronic Health Record Systems

    NASA Astrophysics Data System (ADS)

    Hue, Pham Thi Bach; Wohlgemuth, Sven; Echizen, Isao; Thuy, Dong Thi Bich; Thuc, Nguyen Dinh

    There needs to be a strategy for securing the privacy of patients when exchanging health records between various entities over the Internet. Despite the fact that health care providers such as Google Health and Microsoft Corp.'s Health Vault comply with the U.S Health Insurance Portability and Accountability Act (HIPAA), the privacy of patients is still at risk. Several encryption schemes and access control mechanisms have been suggested to protect the disclosure of a patient's health record especially from unauthorized entities. However, by implementing these approaches, data owners are not capable of controlling and protecting the disclosure of the individual sensitive attributes of their health records. This raises the need to adopt a secure mechanism to protect personal information against unauthorized disclosure. Therefore, we propose a new Fine-grained Access Control (FGAC) mechanism that is based on subkeys, which would allow a data owner to further control the access to his data at the column-level. We also propose a new mechanism to efficiently reduce the number of keys maintained by a data owner in cases when the users have different access privileges to different columns of the data being shared.

  2. Method and device for maximizing memory system bandwidth by accessing data in a dynamically determined order

    NASA Technical Reports Server (NTRS)

    Wulf, William A. (Inventor); McKee, Sally A. (Inventor); Klenke, Robert (Inventor); Schwab, Andrew J. (Inventor); Moyer, Stephen A. (Inventor); Aylor, James (Inventor); Hitchcock, Charles Young (Inventor)

    2000-01-01

    A data processing system is disclosed which comprises a data processor and memory control device for controlling the access of information from the memory. The memory control device includes temporary storage and decision ability for determining what order to execute the memory accesses. The compiler detects the requirements of the data processor and selects the data to stream to the memory control device which determines a memory access order. The order in which to access said information is selected based on the location of information stored in the memory. The information is repeatedly accessed from memory and stored in the temporary storage until all streamed information is accessed. The information is stored until required by the data processor. The selection of the order in which to access information maximizes bandwidth and decreases the retrieval time.

  3. On board processing for future satellite communications systems: Comparison of FDM, TDM and hybrid accessing schemes

    NASA Technical Reports Server (NTRS)

    Berk, G.; Jean, P. N.; Rotholz, E.

    1982-01-01

    Several satellite uplink and downlink accessing schemes for customer premises service are compared. Four conceptual system designs are presented: satellite-routed frequency division multiple access (FDMA), satellite-switched time division multiple access (TDMA), processor-routed TDMA, and frequency-routed TDMA, operating in the 30/20 GHz band. The designs are compared on the basis of estimated satellite weight, system capacity, power consumption, and cost. The systems are analyzed for fixed multibeam coverage of the continental United States. Analysis shows that the system capacity is limited by the available satellite resources and by the terminal size and cost.

  4. All-optical multiplexing schemes for multiple access networks based on wavelet packet filter banks

    NASA Astrophysics Data System (ADS)

    Cincotti, Gabriella; Svaluto Moreolo, Michela; Neri, Alessandro

    2004-08-01

    All optical architectures for Wavelet Packet Division Multiplexing (WPDM) are presented, that can be used in multiple access networks to increase the number of simultaneous users. Wavelet waveform coding spreads data signals both in time and frequency domains, with a large capacity improvement with respect to standard Optical-Code Division Multiple Access (O-CDMA) systems. In addition, the orthogonal property of the wavelet atoms ensures low InterSymbol Interference (ISI) and Multiple Access Interference (MAI) noises. To exploit the large bandwidth capacity of optical fibres, the Optical-Electrical-Optical (O-E-O) conversion is completely avoided, and we designed an all optical system that realizes the WPDM fully in the optical domain. A single Planar Lightwave Circuit (PLC) device multiplies/demultiplies N different users and a diffractive or an integrated optical device performs the waveform coding/decoding. The Wavelet Packet (WP) encoder/decoder is realized as a tree of lattice-form delay-line filters, and can be integrated on a single device along with the optical waveform modulator, resulting in a compact planar optical system. In addition, we show that different choices of WP encoders/decoders are possible to further enhance the system performances.

  5. Improving vascular access outcomes: a systems approach to eliminating structural barriers.

    PubMed

    Sands, Jeffrey J; Perry, Michael A

    2003-01-01

    Maximizing AV fistula creation, regular access monitoring, prompt outpatient interventions and minimizing catheter use are well-accepted approaches for vascular access management. Systemic barriers impede the application of these strategies. A misaligned reimbursement system coupled with educational deficits and a lack of accountability has contributed to the institutionalization of substandard vascular access care. The hallmark of performance management is to create systems in which incentives are aligned to produce desired behaviors. Realigning reimbursement through a combination of pre-ESRD funding, enhancements to the composite rate to reward outcomes and cover vascular access monitoring and updated reimbursement for outpatient vascular access procedures would improve care and decrease unnecessary hospitalizations. This should be coupled with clearly defined outcome standards and accountability incorporated into hospital accreditation and credentialing. Capitation may provide alternative solutions. A two-phased approach including reimbursement reform while exploring capitation represents a prudent course with the best likelihood of success. PMID:12596756

  6. 40 CFR 265.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Access to communications or alarm system. 265.34 Section 265.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or...

  7. 40 CFR 265.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Access to communications or alarm system. 265.34 Section 265.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or...

  8. 40 CFR 265.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Access to communications or alarm system. 265.34 Section 265.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or...

  9. 40 CFR 265.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Access to communications or alarm system. 265.34 Section 265.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or...

  10. 40 CFR 265.34 - Access to communications or alarm system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Access to communications or alarm system. 265.34 Section 265.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or...

  11. Providing Internet Access to the Ohio Career Information System for All Residents: A Feasibility Study.

    ERIC Educational Resources Information Center

    Lewis, Morgan V.

    Expanded Internet access to the Ohio Career Information System (OCIS) would provide adults in Ohio who need to or wish to make career changes with the best available information about occupations, education and training programs, and financial aid. In order to determine the feasibility of improving access without cost to users, an advisory group,…

  12. 28 CFR 16.97 - Exemption of Bureau of Prisons Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.97 Exemption of... Bureau of Prisons facilities; to protect the privacy of third parties; and to protect access to relevant... prevent access of information by record subjects that may invade third party privacy; frustrate...

  13. 28 CFR 16.97 - Exemption of Bureau of Prisons Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.97 Exemption of... Bureau of Prisons facilities; to protect the privacy of third parties; and to protect access to relevant... prevent access of information by record subjects that may invade third party privacy; frustrate...

  14. 28 CFR 16.97 - Exemption of Bureau of Prisons Systems-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.97 Exemption of... Bureau of Prisons facilities; to protect the privacy of third parties; and to protect access to relevant... prevent access of information by record subjects that may invade third party privacy; frustrate...

  15. 28 CFR 16.97 - Exemption of Bureau of Prisons Systems-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.97 Exemption of... Bureau of Prisons facilities; to protect the privacy of third parties; and to protect access to relevant... prevent access of information by record subjects that may invade third party privacy; frustrate...

  16. Evaluation on the Occupational Information Access System as Used at Churchill High School. A Project Report.

    ERIC Educational Resources Information Center

    McKinlay, Bruce; Adams, Daniel

    The Occupational Information Access System (OIAS) improves the accessibility of occupational labor market information for career planning. Its operation at Churchill High School is evaluated from several angels: the likes and dislikes of users; the effect of OIAS on users' knowledge of occupational information and on their career plans; why other…

  17. 75 FR 71790 - Second Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-24

    ... Federal Aviation Administration Second Meeting: RTCA Special Committee 224: Airport Security Access... Committee 224 meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport...

  18. 76 FR 50811 - Eighth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-16

    ... TRANSPORTATION Federal Aviation Administration Eighth Meeting: RTCA Special Committee 224: Airport Security... Committee 224 meeting: Airport Security Access Control Systems. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport Security Access Control...

  19. 78 FR 51810 - Twenty-Fourth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control... RTCA Special Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held on... TRANSPORTATION Federal Aviation Administration Twenty-Fourth Meeting: RTCA Special Committee 224,...

  20. 76 FR 38742 - Seventh Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... Federal Aviation Administration Seventh Meeting: RTCA Special Committee 224: Airport Security Access... Committee 224 meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport...

  1. 76 FR 3931 - Fourth Meeting: RTCA Special Committee 224: Airport Security Access Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... Federal Aviation Administration Fourth Meeting: RTCA Special Committee 224: Airport Security Access... Committee 224 Meeting: Airport Security Access Control Systems (Update to DO-230B). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 224: Airport...

  2. Access Requirement Analysis of E-Governance Systems

    NASA Astrophysics Data System (ADS)

    Kim, Tai-Hoon

    The strategic and contemporary importance of e-governance has been recognized across the world. In India too, various ministries of Govt. of India and State Governments have taken e-governance initiatives to provide e-services to citizens and the business they serve. To achieve the mission objectives, and make such e-governance initiatives successful it would be necessary to improve the trust and confidence of the stakeholders. It is assumed that the delivery of government services will share the same public network information that is being used in the community at large. In particular, the Internet will be the principal means by which public access to government and government services will be achieved. To provide the security measures main aim is to identify user's access requirement for the stakeholders and then according to the models of Nath's approach. Based on this analysis, the Govt. can also make standards of security based on the e-governance models. Thus there will be less human errors and bias. This analysis leads to the security architecture of the specific G2C application.

  3. Electromagnetic Interference Assessment of CDMA and GSM Wireless Phones to Aircraft Navigation Radios

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Nguyen, Truong X.; Koppen, Sandra V.; Salud, M. Theresa

    2002-01-01

    To address the concern for cellular phone electromagnetic interference (EMI) to aircraft radios, a radiated emission measurement process for CDMA (IS-95) and GSM (ETSI GSM 11.22) wireless handsets was developed. Spurious radiated emissions were efficiently characterized from devices tested in either a semi-anechoic or reverberation chamber, in terms of effective isotropic radiated power. Eight representative handsets (4 GSM, 4 CDMA) were commanded to operate while varying their radio transmitter parameters (power, modulation, etc.). This report provides a detailed description of the measurement process and resulting data, which may subsequently be used by others as a basis of consistent evaluation for cellular/PCS phones, Bluetooth, IEEE802.11b, IEEE802.11a, FRS/GMRS radios, and other portable transmitters. Aircraft interference path loss (IPL) and navigation radio interference threshold data from numerous reference documents, standards, and NASA partnerships were compiled. Using this data, a preliminary risk assessment is provided for CDMA and GSM wireless phone interference to aircraft localizer, Glideslope, VOR, and GPS radio receivers on typical transport airplanes. The report identifies where existing data for device emissions, IPL, and navigation radio interference thresholds needs to be extended for an accurate risk assessment for wireless transmitters in aircraft.

  4. SMAC: A soft MAC to reduce control overhead and latency in CDMA-based AMI networks

    SciTech Connect

    Garlapati, Shravan; Kuruganti, Teja; Buehrer, Michael R.; Reed, Jeffrey H.

    2015-10-26

    The utilization of state-of-the-art 3G cellular CDMA technologies in a utility owned AMI network results in a large amount of control traffic relative to data traffic, increases the average packet delay and hence are not an appropriate choice for smart grid distribution applications. Like the CDG, we consider a utility owned cellular like CDMA network for smart grid distribution applications and classify the distribution smart grid data as scheduled data and random data. Also, we propose SMAC protocol, which changes its mode of operation based on the type of the data being collected to reduce the data collection latency and control overhead when compared to 3G cellular CDMA2000 MAC. The reduction in the data collection latency and control overhead aids in increasing the number of smart meters served by a base station within the periodic data collection interval, which further reduces the number of base stations needed by a utility or reduces the bandwidth needed to collect data from all the smart meters. The reduction in the number of base stations and/or the reduction in the data transmission bandwidth reduces the CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX) of the AMI network. Finally, the proposed SMAC protocol is analyzed using markov chain, analytical expressions for average throughput and average packet delay are derived, and simulation results are also provided to verify the analysis.

  5. SMAC: A soft MAC to reduce control overhead and latency in CDMA-based AMI networks

    DOE PAGES

    Garlapati, Shravan; Kuruganti, Teja; Buehrer, Michael R.; Reed, Jeffrey H.

    2015-10-26

    The utilization of state-of-the-art 3G cellular CDMA technologies in a utility owned AMI network results in a large amount of control traffic relative to data traffic, increases the average packet delay and hence are not an appropriate choice for smart grid distribution applications. Like the CDG, we consider a utility owned cellular like CDMA network for smart grid distribution applications and classify the distribution smart grid data as scheduled data and random data. Also, we propose SMAC protocol, which changes its mode of operation based on the type of the data being collected to reduce the data collection latency andmore » control overhead when compared to 3G cellular CDMA2000 MAC. The reduction in the data collection latency and control overhead aids in increasing the number of smart meters served by a base station within the periodic data collection interval, which further reduces the number of base stations needed by a utility or reduces the bandwidth needed to collect data from all the smart meters. The reduction in the number of base stations and/or the reduction in the data transmission bandwidth reduces the CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX) of the AMI network. Finally, the proposed SMAC protocol is analyzed using markov chain, analytical expressions for average throughput and average packet delay are derived, and simulation results are also provided to verify the analysis.« less

  6. Multigenerational effects of whole body exposure to 2.14 GHz W-CDMA cellular phone signals on brain function in rats.

    PubMed

    Shirai, Tomoyuki; Imai, Norio; Wang, Jianqing; Takahashi, Satoru; Kawabe, Mayumi; Wake, Kanako; Kawai, Hiroki; Watanabe, So-Ichi; Furukawa, Fumio; Fujiwara, Osamu

    2014-10-01

    The present experimental study was carried out with rats to evaluate the effects of whole body exposure to 2.14 GHz band code division multiple access (W-CDMA) signals for 20 h a day, over three generations. The average specific absorption rate (SAR, in unit of W/kg) for dams was designed at three levels: high (<0.24 W/kg), low (<0.08 W/kg), and 0 (sham exposure). Pregnant mothers (4 rats/group) were exposed from gestational day (GD) 7 to weaning and then their offspring (F1 generation, 4 males and 4 females/dam, respectively) were continuously exposed until 6 weeks of age. The F1 females were mated with F1 males at 11 weeks old, and then starting from GD 7, they were exposed continuously to the electromagnetic field (EMF; one half of the F1 offspring was used for mating, that is, two of each sex per dam and 8 males and 8 females/group, except for all offspring for the functional development tests). This protocol was repeated in the same manner on pregnant F2 females and F3 pups; the latter were killed at 10 weeks of age. No abnormalities were observed in the mother rats (F0 , F1 , and F2 ) and in the offspring (F1 , F2 , and F3 ) in any biological parameters, including neurobehavioral function. Thus, it was concluded that under the experimental conditions applied, multigenerational whole body exposure to 2.14 GHz W-CDMA signals for 20 h/day did not cause any adverse effects on the F1 , F2 , and F3 offspring.

  7. REVIEW: Widespread access to predictive models in the motor system: a short review

    NASA Astrophysics Data System (ADS)

    Davidson, Paul R.; Wolpert, Daniel M.

    2005-09-01

    Recent behavioural and computational studies suggest that access to internal predictive models of arm and object dynamics is widespread in the sensorimotor system. Several systems, including those responsible for oculomotor and skeletomotor control, perceptual processing, postural control and mental imagery, are able to access predictions of the motion of the arm. A capacity to make and use predictions of object dynamics is similarly widespread. Here, we review recent studies looking at the predictive capacity of the central nervous system which reveal pervasive access to forward models of the environment.

  8. Effects on rat testis of 1.95-GHz W-CDMA for IMT-2000 cellular phones.

    PubMed

    Imai, Norio; Kawabe, Mayumi; Hikage, Takashi; Nojima, Toshio; Takahashi, Satoru; Shirai, Tomoyuki

    2011-08-01

    In recent years concern has arisen whether carrying a cellular phone near the reproductive organs such as the testes may cause dysfunction and particularly decrease in sperm development and production, and thus fertility in men. The present study was performed to investigate the effects of a 1.95 GHz electromagnetic field on testicular function in male Sprague-Dawley rats. Five week old animals were divided into 3 groups of 24 each and a 1.95-GHz wide-band code division multiple access (W-CDMA) signal, which is used for the freedom of mobile multimedia access (FOMA), was employed for whole body exposure for 5 hours per day, 7 days a week for 5 weeks (the period from the age of 5 to 10 weeks, corresponding to reproductive maturation in the rat). Whole-body average specific absorption rates (SAR) for individuals were designed to be 0.4 and 0.08 W/kg respectively. The control group received sham exposure. There were no differences in body weight gain or weights of the testis, epididymis, seminal vesicles, and prostate among the groups. The number of sperm in the testis and epididymis were not decreased in the electromagnetic field (EMF) exposed groups, and, in fact, the testicular sperm count was significantly increased with the 0.4 SAR. Abnormalities of sperm motility or morphology and the histological appearance of seminiferous tubules, including the stage of the spermatogenic cycle, were not observed. Thus, under the present exposure conditions, no testicular toxicity was evident.

  9. ACCESS computer program for the synthesis of large structural systems

    NASA Technical Reports Server (NTRS)

    Fleury, C.; Ramanathan, R. K.; Salama, M.; Schmit, L. A., Jr.

    1982-01-01

    The structural-synthesis computer code ACCESS-3, originally limited to the optimization of relatively simple problems involving truss, membrane, and shear panel elements, has been restructured to make it applicable to structures with a larger number of degrees-of-freedom, design variables, and constraints. The modifications made allow the use of six degrees-of-freedom per node and permit the out-of-core solution of large matrix equations encountered at the analysis stage. Also, finite elements which permit pure bending as well as combined bending and membrane (axial) behavior have been added to satisfy the need for a more comprehensive set of elements. Like its predecessor, the new version of the program combines the approximation concepts with primal or dual formulations to provide an efficient optimization tool.

  10. Circulation Systems Interface via Dial-Up Access.

    ERIC Educational Resources Information Center

    Gosier, L. James; Crisco, Mary E.

    1982-01-01

    Describes the development of telephone communications links between automated circulation systems in six public library systems in the state of Maryland, and discusses the implications of such links for interlibrary loan programs. (JL)

  11. Accessing PCS Remotely across a Rural County Library System

    ERIC Educational Resources Information Center

    McGeehon, Carol; Millar, Don

    2004-01-01

    The Douglas County Library System (DCLS) is a rural system in Southern Oregon. It's headquarters library is centrally located in Roseburg. DCLS serves a population of 100,000 with the largest concentration of people within 15 miles from the Pacific ocean. Because the library system supports around 150 machines scattered across 11 sites, it needs a…

  12. Systemic barriers accessing HIV treatment among people who inject drugs in Russia: a qualitative study

    PubMed Central

    Sarang, Anya; Rhodes, Tim; Sheon, Nicolas

    2013-01-01

    Achieving ‘universal access’ to antiretroviral HIV treatment (ART) in lower income and transitional settings is a global target. Yet, access to ART is shaped by local social condition and is by no means universal. Qualitative studies are ideally suited to describing how access to ART is socially situated. We explored systemic barriers to accessing ART among people who inject drugs (PWID) in a Russian city (Ekaterinburg) with a large burden of HIV treatment demand. We undertook 42 in-depth qualitative interviews with people living with HIV with current or recent experience of injecting drug use. Accounts were analysed thematically, and supplemented here with an illustrative case study. Three core themes were identified: ‘labyrinthine bureaucracy’ governing access to ART; a ‘system Catch 22’ created by an expectation that access to ART was conditional upon treated drug use in a setting of limited drug treatment opportunity; and ‘system verticalization’, where a lack of integration across HIV, tuberculosis (TB) and drug treatment compromised access to ART. Taken together, we find that systemic factors play a key role in shaping access to ART with the potential adverse effects of reproducing treatment initiation delay and disengagement from treatment. We argue that meso-level systemic factors affecting access to ART for PWID interact with wider macro-level structural forces, including those related to drug treatment policy and the social marginalization of PWID. We note the urgent need for systemic and structural changes to improve access to ART for PWID in this setting, including to simplify bureaucratic procedures, foster integrated HIV, TB and drug treatment services, and advocate for drug treatment policy reform. PMID:23197431

  13. 75 FR 4101 - Enterprise Income Verification (EIV) System User Access Authorization Form and Rules of Behavior...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... the Chief Information Officer. BILLING CODE 4210-67-P ... URBAN DEVELOPMENT Enterprise Income Verification (EIV) System User Access Authorization Form and Rules of Behavior and User Agreement AGENCY: Office of the Chief Information Officer, HUD. ACTION:...

  14. Utility-Interconnected Photovoltaic Systems: Evaluating the Rationale for the Utility-Accessible External Disconnect Switch

    SciTech Connect

    Coddington, M.; Margolis, R.M.; Aabakken, J.

    2008-01-01

    The utility-accessible alternating current (AC) external disconnect switch (EDS) for distributed generators, including photovoltaic (PV) systems, is a hardware feature that allows a utility?s employees to manually disconnect a customer-owned generator from the electricity grid. This paper examines the utility-accessible EDS debate in the context of utility-interactive PV systems for residential and small commercial installations. It also evaluates the rationale for EDS requirements.

  15. Improving patient access and streamlining processes through enterprise intelligence systems.

    PubMed

    Dunn, Ronald L

    2014-01-01

    This article demonstrates how enterprise intelligence systems can be used to improve operational efficiency in hospitals. Enterprise intelligence systems mine raw data from disparate systems and transform the data into actionable information, which when used appropriately, support streamlined processes, optimize resources, and positively affect staff efficiency and the quality of patient care. Case studies on the implementation of McKesson Performance Visibility and Capacity Planner enterprise intelligence solutions at the Southlake Regional Health Centre and Lions Gate and Richmond Hospitals are provided.

  16. Thermodynamic Entropy and the Accessible States of Some Simple Systems

    ERIC Educational Resources Information Center

    Sands, David

    2008-01-01

    Comparison of the thermodynamic entropy with Boltzmann's principle shows that under conditions of constant volume the total number of arrangements in a simple thermodynamic system with temperature-independent constant-volume heat capacity, C, is T[superscript C/k]. A physical interpretation of this function is given for three such systems: an…

  17. Ask Systems: Interrogative Access to Multiple Ways of Thinking

    ERIC Educational Resources Information Center

    Jonassen, David H.

    2011-01-01

    The purpose of this paper is to familiarize instructional designers and researchers with a useful design and research paradigm known as "Ask Systems." Ask Systems are interrogative interfaces to information and learning environments that model conversations with a skilled, reflective practitioner (Schon, The reflective practitioner, "1983") or…

  18. Difficulties experienced by trans people in accessing the Unified Health System.

    PubMed

    Rocon, Pablo Cardozo; Rodrigues, Alexsandro; Zamboni, Jésio; Pedrini, Mateus Dias

    2016-08-01

    The objective of this study was to discuss the difficulties of trans people living in the metropolitan region of Greater Vitória, Espírito Santo, Brazil, in accessing the health services of the Unified Health System (Sistema Único de Saúde - SUS). We used a qualitative approach through semi-structured interviews with 15 trans people. The results point to disrespect toward the adopted name, discrimination, and the diagnosis required for the gender reassignment process as major limitations to accessing the healthcare system. The diagnosis helps hide the responsibility of heteronormativity and gender binarism in the social marginalization of trans people. It is concluded that it is necessary to review the issue of diagnosis, given that the existence of a prior pathology is not required to access the SUS. It is important to develop educational programmes and permanent campaigns concerning the right to access the healthcare system free from discrimination and to use the adopted name.

  19. Access to care for Chagas disease in the United States: a health systems analysis.

    PubMed

    Manne-Goehler, Jennifer; Reich, Michael R; Wirtz, Veronika J

    2015-07-01

    There are 300,000 estimated cases of Chagas disease in the United States but limited data on access to care. This study analyzed trends in access to care for Chagas disease in the United States and assessed the national and state barriers to access. Data on cases in blood donors and drug releases were obtained from the AABB (formerly American Association of Blood Banks) and U.S. Centers for Disease Control and Prevention (CDC), respectively. Semi-structured in-depth interviews were conducted with 30 key informants at the national level and in five states where treatment had been released. Interview responses were analyzed according to the health systems dimensions of regulation, financing, payment, organization, and persuasion. Data indicate that 1,908 cases were identified in the blood donation system from 2007 to 2013 and that CDC released 422 courses of benznidazole or nifurtimox during this period. The barriers to access at the national level include limited diagnostic and institutionalized referral and care processes, lack of financing for patient-care activities, and limited awareness and training among providers. This study demonstrates that access to treatment of Chagas disease in the United States is limited. The lack of licensing is only one of several barriers to access, highlighting the need for a health systems perspective when scaling up access to these essential medicines.

  20. Prospective evaluation of an internet-linked handheld computer critical care knowledge access system

    PubMed Central

    Lapinsky, Stephen E; Wax, Randy; Showalter, Randy; Martinez-Motta, J Carlos; Hallett, David; Mehta, Sangeeta; Burry, Lisa; Stewart, Thomas E

    2004-01-01

    Introduction Critical care physicians may benefit from immediate access to medical reference material. We evaluated the feasibility and potential benefits of a handheld computer based knowledge access system linking a central academic intensive care unit (ICU) to multiple community-based ICUs. Methods Four community hospital ICUs with 17 physicians participated in this prospective interventional study. Following training in the use of an internet-linked, updateable handheld computer knowledge access system, the physicians used the handheld devices in their clinical environment for a 12-month intervention period. Feasibility of the system was evaluated by tracking use of the handheld computer and by conducting surveys and focus group discussions. Before and after the intervention period, participants underwent simulated patient care scenarios designed to evaluate the information sources they accessed, as well as the speed and quality of their decision making. Participants generated admission orders during each scenario, which were scored by blinded evaluators. Results Ten physicians (59%) used the system regularly, predominantly for nonmedical applications (median 32.8/month, interquartile range [IQR] 28.3–126.8), with medical software accessed less often (median 9/month, IQR 3.7–13.7). Eight out of 13 physicians (62%) who completed the final scenarios chose to use the handheld computer for information access. The median time to access information on the handheld handheld computer was 19 s (IQR 15–40 s). This group exhibited a significant improvement in admission order score as compared with those who used other resources (P = 0.018). Benefits and barriers to use of this technology were identified. Conclusion An updateable handheld computer system is feasible as a means of point-of-care access to medical reference material and may improve clinical decision making. However, during the study, acceptance of the system was variable. Improved training and new

  1. Signal restoration in intensity-modulated optical OFDM access systems.

    PubMed

    Vanin, Evgeny

    2011-11-15

    It is well known that deliberate signal clipping in an intensity-modulated (IM) laser transmitter helps to overcome the optical orthogonal frequency division multiplexing (OFDM) system performance limitation that is related to the signal high peak-to-average power ratio. The amplitude of a clipped OFDM signal has to be optimized in order to minimize the optical power that is required to achieve a specified system performance. However, the signal clipping introduces nonlinear distortion (so-called clipping noise) and leads to a system performance penalty. In this Letter, the performance of the IM optical OFDM system with digital baseband clipping distortion in the transmitter and clipping noise compensation by means of signal restoration in the digital signal processing unit of the system receiver is analytically evaluated. It is demonstrated that the system bit-error ratio can be reduced by more than an order of magnitude, from 10(-3) to 3.5×10(-5), by applying only the first iteration of the signal restoration algorithm proposed in this Letter. The results of the analytical analysis are verified with brute-force numerical simulations based on direct error counting. PMID:22089556

  2. 28 CFR 16.73 - Exemption of Office of Legal Policy System-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... System-limited access. 16.73 Section 16.73 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR....S.C. 552a(d)(1) and (e)(1): (1) U.S. Judges Records System (JUSTICE/OLP-002). These exemptions apply...): (1) Declassification Review System (JUSTICE/OLP-004). These exemptions apply only to the extent...

  3. 28 CFR 16.89 - Exemption of Civil Division Systems-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Division Case File System, JUSTICE/CIV-001. (2) Freedom of Information/Privacy Acts File System, JUSTICE...)(2) from subsections (c)(3), (d), and (e)(1). Consumer Inquiry/Investigatory System, JUSTICE/CIV-006...-limited access. 16.89 Section 16.89 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR...

  4. 28 CFR 16.89 - Exemption of Civil Division Systems-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Division Case File System, JUSTICE/CIV-001. (2) Freedom of Information/Privacy Acts File System, JUSTICE...)(2) from subsections (c)(3), (d), and (e)(1). Consumer Inquiry/Investigatory System, JUSTICE/CIV-006...-limited access. 16.89 Section 16.89 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR...

  5. 28 CFR 16.73 - Exemption of Office of Legal Policy System-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... System-limited access. 16.73 Section 16.73 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR....S.C. 552a(d)(1) and (e)(1): (1) U.S. Judges Records System (JUSTICE/OLP-002). These exemptions apply...): (1) Declassification Review System (JUSTICE/OLP-004). These exemptions apply only to the extent...

  6. 28 CFR 16.89 - Exemption of Civil Division Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Division Case File System, JUSTICE/CIV-001. (2) Freedom of Information/Privacy Acts File System, JUSTICE...)(2) from subsections (c)(3), (d), and (e)(1). Consumer Inquiry/Investigatory System, JUSTICE/CIV-006...-limited access. 16.89 Section 16.89 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR...

  7. 28 CFR 16.73 - Exemption of Office of Legal Policy System-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... System-limited access. 16.73 Section 16.73 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR....S.C. 552a(d)(1) and (e)(1): (1) U.S. Judges Records System (JUSTICE/OLP-002). These exemptions apply...): (1) Declassification Review System (JUSTICE/OLP-004). These exemptions apply only to the extent...

  8. 28 CFR 16.97 - Exemption of Bureau of Prisons Systems-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Exemption of Bureau of Prisons Systems... OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.97 Exemption of Bureau of Prisons Systems—limited access. (a) The following systems of records are exempt from 5...

  9. 28 CFR 16.73 - Exemption of Office of Legal Policy System-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) and (4); (d); (e)(1), (2) and (3), (e)(4)(G) and (H) (e)(5); and (g): (1) General Files System of the... System-limited access. 16.73 Section 16.73 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.73 Exemption...

  10. 5 CFR 293.504 - Composition of, and access to, the Employee Medical File System.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Employee Medical File System. 293.504 Section 293.504 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Employee Medical File System Records § 293.504 Composition of, and access to, the Employee Medical File System. (a) All employee occupational medical...

  11. Man-computer Inactive Data Access System (McIDAS). [design, development, fabrication, and testing

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A technical description is given of the effort to design, develop, fabricate, and test the two dimensional data processing system, McIDAS. The system has three basic sections: an access and data archive section, a control section, and a display section. Areas reported include hardware, system software, and applications software.

  12. Internal crankcase ventilation system with easily accessible PCV valve

    SciTech Connect

    Balsley, R.L.

    1986-07-29

    A crankcase ventilation system is described having a flow limiting PCV valve and means defining and internal passage between a crankcase and a cylinder charge induction means of an engine, the system comprising an engine valve cover forming a part of the internal passage defining means and having an exterior wall, a cavity in the cover wall and forming a portion of the internal passage, the wall further including valve mounting means surrounding the passage and receiving the valve and a valve body seal in position to control flow through the mounting means and passage and an opening through the wall to the housing exterior and generally opposite the mounting means for removing and replacing a valve on the mounting means, and closure means normally closing the opening and preventing air leakage therethrough into the induction system, the closure means engaging the valve to maintain its installed position within the wall cavity and being openable to permit removal of the PCV valve.

  13. Accessibility of blood glucose monitoring systems for blind and visually impaired people.

    PubMed

    Uslan, Mark M; Eghtesadi, Khosrow; Burton, Darren

    2003-01-01

    Blindness and visual impairment are prevalent among people with diabetes. Blood glucose monitoring systems (BGMSs) have revolutionized diabetes care, but none of the 30 or so commercially available monitoring systems was designed to be fully accessible to blind and visually impaired persons. Seventeen BGMSs were evaluated for accessible use by people who are blind or visually impaired. Features and functionalities (e.g., operating procedures, user interface design, device specifications, and computer interface capabilities) were examined and tabulated, as was usability and accessibility. A subset of these systems with the highest degree of accessibility was selected and thoroughly examined and tested. Additionally, 12 people who are blind or visually impaired and who were issued BGMSs by their physician or diabetes educator were interviewed and videotaped using their meters. Of the 17 BGMSs, only four had voice output capability, an essential component of accessibility for blind and visually impaired persons. The six BGMSs without voice output that had the largest display fonts were found to have few accessibility features for visually impaired persons. Users indicated that voice output and portability were desired attributes of an accessible BGMS. None of the BGMSs evaluated had all of the required accessibility attributes, including the four systems that had voice output capability. The four systems with voice output were much bulkier and heavier than those that did not have this capability. Recommendations are made for design and development of BGMSs that would increase effective usage by blind and visually impaired persons, including integrating text to speech and streamlining the blood glucose monitoring process. PMID:12828828

  14. Access to Biomedical Information: The Unified Medical Language System.

    ERIC Educational Resources Information Center

    Squires, Steven J.

    1993-01-01

    Describes the development of a Unified Medical Language System (UMLS) by the National Library of Medicine that will retrieve and integrate information from a variety of information resources. Highlights include the metathesaurus; the UMLS semantic network; semantic locality; information sources map; evaluation of the metathesaurus; future…

  15. Finding a Target with an Accessible Global Positioning System

    ERIC Educational Resources Information Center

    Ponchillia, Paul E.; MacKenzie, Nancy; Long, Richard G.; Denton-Smith, Pamela; Hicks, Thomas L.; Miley, Priscilla

    2007-01-01

    This article presents two target-location experiments. In the first experiment, 19 participants located a 25-foot chalk circle 93% of the time with a Global Positioning System (GPS) compared to 12% of the time without it. In a single-subject follow-up experiment, the participant came within 1 foot of the target on all GPS trials. Target-location…

  16. Program partitioning for NUMA multiprocessor computer systems. [Nonuniform memory access

    SciTech Connect

    Wolski, R.M.; Feo, J.T. )

    1993-11-01

    Program partitioning and scheduling are essential steps in programming non-shared-memory computer systems. Partitioning is the separation of program operations into sequential tasks, and scheduling is the assignment of tasks to processors. To be effective, automatic methods require an accurate representation of the model of computation and the target architecture. Current partitioning methods assume today's most prevalent models -- macro dataflow and a homogeneous/two-level multicomputer system. Based on communication channels, neither model represents well the emerging class of NUMA multiprocessor computer systems consisting of hierarchical read/write memories. Consequently, the partitions generated by extant methods do not execute well on these systems. In this paper, the authors extend the conventional graph representation of the macro-dataflow model to enable mapping heuristics to consider the complex communication options supported by NUMA architectures. They describe two such heuristics. Simulated execution times of program graphs show that the model and heuristics generate higher quality program mappings than current methods for NUMA architectures.

  17. Grievance and Redress: Chicano Access to the Criminal Justice System.

    ERIC Educational Resources Information Center

    Geilhufe, Nancy L.

    Focusing on the processes involved in making formal bureaucracies responsive, the study examined: the structure of formal grievance and redress procedures within the criminal justice system in San Jose, California; and the informal strategies used by politically active members of the Chicano community to extend and strengthen these channels. The…

  18. Engaging a Systemic Partnership to Increase College Access and Success

    ERIC Educational Resources Information Center

    Benson, Gwen; McClendon, Susan Crim

    2008-01-01

    Systemic, university-school-community partnerships characterize efforts by Georgia State University to enhance preparation of urban teachers and urban student success. A partnership with the Atlanta Housing Authority focuses on family education in mixed-income communities. Work with the National Parks Service's Martin Luther King, Jr., Center…

  19. Labeling and Rating Systems: Greater Access or Censorship?

    ERIC Educational Resources Information Center

    Martin, Ann M.

    2015-01-01

    This article asks the question: How well versed are school librarians on issues related to labeling and rating systems? As school librarians continue to design and implement resource location schemes to assist patrons, they must recognize the difference between using labels to create interest in books or implementing labeling and rating systems…

  20. Generation-based memory synchronization in a multiprocessor system with weakly consistent memory accesses

    SciTech Connect

    Ohmacht, Martin

    2014-09-09

    In a multiprocessor system, a central memory synchronization module coordinates memory synchronization requests responsive to memory access requests in flight, a generation counter, and a reclaim pointer. The central module communicates via point-to-point communication. The module includes a global OR reduce tree for each memory access requesting device, for detecting memory access requests in flight. An interface unit is implemented associated with each processor requesting synchronization. The interface unit includes multiple generation completion detectors. The generation count and reclaim pointer do not pass one another.

  1. Mercury- Distributed Metadata Management, Data Discovery and Access System

    NASA Astrophysics Data System (ADS)

    Palanisamy, Giri; Wilson, Bruce E.; Devarakonda, Ranjeet; Green, James M.

    2007-12-01

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source and ORNL- developed software. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. Mercury supports various metadata standards including XML, Z39.50, FGDC, Dublin-Core, Darwin-Core, EML, and ISO-19115 (under development). Mercury provides a single portal to information contained in disparate data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow the users to perform simple, fielded, spatial and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury supports various projects including: ORNL DAAC, NBII, DADDI, LBA, NARSTO, CDIAC, OCEAN, I3N, IAI, ESIP and ARM. The new Mercury system is based on a Service Oriented Architecture and supports various services such as Thesaurus Service, Gazetteer Web Service and UDDI Directory Services. This system also provides various search services including: RSS, Geo-RSS, OpenSearch, Web Services and Portlets. Other features include: Filtering and dynamic sorting of search results, book-markable search results, save, retrieve, and modify search criteria.

  2. RAPID: A random access picture digitizer, display, and memory system

    NASA Technical Reports Server (NTRS)

    Yakimovsky, Y.; Rayfield, M.; Eskenazi, R.

    1976-01-01

    RAPID is a system capable of providing convenient digital analysis of video data in real-time. It has two modes of operation. The first allows for continuous digitization of an EIA RS-170 video signal. Each frame in the video signal is digitized and written in 1/30 of a second into RAPID's internal memory. The second mode leaves the content of the internal memory independent of the current input video. In both modes of operation the image contained in the memory is used to generate an EIA RS-170 composite video output signal representing the digitized image in the memory so that it can be displayed on a monitor.

  3. Design of pulse waveform for waveform division multiple access UWB wireless communication system.

    PubMed

    Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

    2014-01-01

    A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study.

  4. Rules and access rights of the Estonian integrated e-Health system.

    PubMed

    Tiik, Madis

    2010-01-01

    There should be a clear understanding that when implementing an electronic health record system (EHR), one of the hardest problems we have to solve is the access rights. In Estonia this process lasted for three years and involved all stakeholders of the healthcare sector. Special ethical committee was established to advise the decision makers and doctors to help them understand the ethical dilemmas from the patient's and society's point of view. In this article you will find a short overview of the access rights of the system, roles of the healthcare systems' employees. Descriptions of some specific situations like underage patients and representation of patient with restricted active legal capacity.

  5. An Information System to Access Status Information of the LHCb Online

    NASA Astrophysics Data System (ADS)

    Frank, M.; Gaspar, C.

    2012-12-01

    The LHCb collaboration consists of roughly 700 physicists from 52 institutes and universities. Most of the collaborating physicists - including subdetector experts - are not permanently based at CERN. This paper describes the architecture used to publish data internal to the LHCb experiment control- and data acquisition system to the World Wide Web. Collaborators can access the online (sub-) system status and the system performance directly from the institute abroad, from home or from a smart phone without the need of direct access to the online computing infrastructure.

  6. A novel wireless local positioning system for airport (indoor) security

    NASA Astrophysics Data System (ADS)

    Zekavat, Seyed A.; Tong, Hui; Tan, Jindong

    2004-09-01

    A novel wireless local positioning system (WLPS) for airport (or indoor) security is introduced. This system is used by airport (indoor) security guards to locate all of, or a group of airport employees or passengers within the airport area. WLPS consists of two main parts: (1) a base station that is carried by security personnel; hence, introducing dynamic base station (DBS), and (2) a transponder (TRX) that is mounted on all people (including security personnel) present at the airport; thus, introducing them as active targets. In this paper, we (a) draw a futuristic view of the airport security systems, and the flow of information at the airports, (b) investigate the techniques of extending WLPS coverage area beyond the line-of-sight (LoS), and (c) study the performance of this system via standard transceivers, and direct sequence code division multiple access (DS-CDMA) systems with and without antenna arrays and conventional beamforming (BF).

  7. Access to Essential Medicines in Pakistan: Policy and Health Systems Research Concerns

    PubMed Central

    Zaidi, Shehla; Bigdeli, Maryam; Aleem, Noureen; Rashidian, Arash

    2013-01-01

    Introduction Inadequate access to essential medicines is a common issue within developing countries. Policy response is constrained, amongst other factors, by a dearth of in-depth country level evidence. We share here i) gaps related to access to essential medicine in Pakistan; and ii) prioritization of emerging policy and research concerns. Methods An exploratory research was carried out using a health systems perspective and applying the WHO Framework for Equitable Access to Essential Medicine. Methods involved key informant interviews with policy makers, providers, industry, NGOs, experts and development partners, review of published and grey literature, and consultative prioritization in stakeholder’s Roundtable. Findings A synthesis of evidence found major gaps in essential medicine access in Pakistan driven by weaknesses in the health care system as well as weak pharmaceutical regulation. 7 major policy concerns and 11 emerging research concerns were identified through consultative Roundtable. These related to weaknesses in medicine registration and quality assurance systems, unclear and counterproductive pricing policies, irrational prescribing and sub-optimal drug availability. Available research, both locally and globally, fails to target most of the identified policy concerns, tending to concentrate on irrational prescriptions. It overlooks trans-disciplinary areas of policy effectiveness surveillance, consumer behavior, operational pilots and pricing interventions review. Conclusion Experience from Pakistan shows that policy concerns related to essential medicine access need integrated responses across various components of the health systems, are poorly addressed by existing evidence, and require an expanded health systems research agenda. PMID:23717442

  8. Using geographic information systems to simulate patient access areas.

    PubMed

    Doi, Shunsuke; Inoue, Takashi; Ide, Hiroo; Nakamura, Toshihito; Fujita, Shinsuke; Suzuki, Takahiro; Takabayashi, Katsuhiko

    2014-01-01

    We constructed a simulation model with a geographic information system (GIS) to predict the future shortage of beds in the Tokyo Metropolitan Area. With a grid square method, we calculated patient numbers for every 500 square meters of the Tokyo Metropolitan Area until 2040 and estimated whether those in need could be admitted to hospitals within an hour's drive from their homes. The simulation demonstrates that after 2025 many patients may not be able to find hospitals within this time framework. The situation will be especially serious in the center of Tokyo and along the railway lines, where many senior citizens reside. We can now apply this innovative GIS method in many fields and especially for the precise estimation of future demands for and supply of medical assistance.

  9. Analysis of the TDRS multiple access system for possible use as an attitude control system sensor

    NASA Technical Reports Server (NTRS)

    Blevins, Bruce Allyn; Sank, Victor J.

    1993-01-01

    A member of the constellation of TDR satellites (TDRS) has experienced a failure of its prime earth sensor. Failure of the remaining earth sensor could result in the inability of the satellite to control its attitude and provide user services. Loss of the satellite would be a serious event. The multiple access (MA) antenna array on the TDRS has been proposed for use as a backup sensor for the attitude control system. This paper describes our analysis of the performance of the MA array as an interferometer used for accurate attitude determination. A least squares fit of a plane to the MA phase information appears to represent the TDRS body roll and pitch within about 0.1 deg. This is sufficient for SGL pointing and MA and SSA user services. Analytic improvements that include ionospheric correction may yield sufficient accuracy for KSA user services.

  10. The Public-Access Computer Systems Forum: A Computer Conference on BITNET.

    ERIC Educational Resources Information Center

    Bailey, Charles W., Jr.

    1990-01-01

    Describes the Public Access Computer Systems Forum (PACS), a computer conference that deals with all computer systems that libraries make available to patrons. Areas discussed include how to subscribe to PACS, message distribution and retrieval capabilities, subscriber lists, documentation, generic list server capabilities, and other…

  11. 28 CFR 16.96 - Exemption of Federal Bureau of Investigation Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... to correct inaccuracies in it. Although an alternate system of access has been provided in 28 CFR 16.30 to 34 and 28 CFR 20.34, the vast majority of records in this system concern local arrests which it... criminal history records in the National Crime Information Center is available to the individual who is...

  12. 28 CFR 16.96 - Exemption of Federal Bureau of Investigation Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... to correct inaccuracies in it. Although an alternate system of access has been provided in 28 CFR 16.30 to 34 and 28 CFR 20.34, the vast majority of records in this system concern local arrests which it... criminal history records in the National Crime Information Center is available to the individual who is...

  13. 28 CFR 16.96 - Exemption of Federal Bureau of Investigation Systems-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to correct inaccuracies in it. Although an alternate system of access has been provided in 28 CFR 16.30 to 34 and 28 CFR 20.34, the vast majority of records in this system concern local arrests which it... criminal history records in the National Crime Information Center is available to the individual who is...

  14. 28 CFR 16.96 - Exemption of Federal Bureau of Investigation Systems-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... to correct inaccuracies in it. Although an alternate system of access has been provided in 28 CFR 16.30 to 34 and 28 CFR 20.34, the vast majority of records in this system concern local arrests which it... criminal history records in the National Crime Information Center is available to the individual who is...

  15. 28 CFR 16.96 - Exemption of Federal Bureau of Investigation Systems-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... to correct inaccuracies in it. Although an alternate system of access has been provided in 28 CFR 16.30 to 34 and 28 CFR 20.34, the vast majority of records in this system concern local arrests which it... provided in 28 CFR, part 25, subpart A. (4) From subsection (e)(1) because it is impossible to state...

  16. HEDS - EPA DATABASE SYSTEM FOR PUBLIC ACCESS TO HUMAN EXPOSURE DATA

    EPA Science Inventory

    Human Exposure Database System (HEDS) is an Internet-based system developed to provide public access to human-exposure-related data from studies conducted by EPA's National Exposure Research Laboratory (NERL). HEDS was designed to work with the EPA Office of Research and Devel...

  17. 28 CFR 16.99 - Exemption of the Immigration and Naturalization Service Systems-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Exemption of the Immigration and....99 Exemption of the Immigration and Naturalization Service Systems-limited access. (a) The following systems of records of the Immigration and Naturalization Service are exempt from 5 U.S.C. 552a (c) (3)...

  18. 28 CFR 16.99 - Exemption of the Immigration and Naturalization Service Systems-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Exemption of the Immigration and....99 Exemption of the Immigration and Naturalization Service Systems-limited access. (a) The following systems of records of the Immigration and Naturalization Service are exempt from 5 U.S.C. 552a (c) (3)...

  19. 28 CFR 16.99 - Exemption of the Immigration and Naturalization Service Systems-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Exemption of the Immigration and....99 Exemption of the Immigration and Naturalization Service Systems-limited access. (a) The following systems of records of the Immigration and Naturalization Service are exempt from 5 U.S.C. 552a (c) (3)...

  20. 28 CFR 16.99 - Exemption of the Immigration and Naturalization Service Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Exemption of the Immigration and....99 Exemption of the Immigration and Naturalization Service Systems-limited access. (a) The following systems of records of the Immigration and Naturalization Service are exempt from 5 U.S.C. 552a (c) (3)...

  1. 28 CFR 16.99 - Exemption of the Immigration and Naturalization Service Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of the Immigration and....99 Exemption of the Immigration and Naturalization Service Systems-limited access. (a) The following systems of records of the Immigration and Naturalization Service are exempt from 5 U.S.C. 552a (c) (3)...

  2. 28 CFR 16.93 - Exemption of Tax Division Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Tax Division Systems-limited... Division Systems—limited access. (a) The following systems of records are exempted pursuant to the...) Tax Division Central Classification Cards, Index Docket Cards, and Associated Records—Criminal...

  3. Functional requirements with survey results for integrated intrusion detection and access control annunciator systems

    SciTech Connect

    Arakaki, L.H.; Monaco, F.M.

    1995-09-01

    This report contains the guidance Functional Requirements for an Integrated Intrusion Detection and Access Control Annunciator System, and survey results of selected commercial systems. The survey questions were based upon the functional requirements; therefore, the results reflect which and sometimes how the guidance recommendations were met.

  4. Access to the Albanian VET System: Social, Individual and School-Based Barriers

    ERIC Educational Resources Information Center

    Xhumari, Merita; Dibra, Sidita

    2016-01-01

    This article analyses the determinants of access to the VET system in Albania and its impact on the inclusion of young people and vulnerable groups. The VET system often attracts students who have completed the compulsory levels of education with weak academic results. Many come from families with a low level of income and a low education level.…

  5. Environmental Information Management For Data Discovery and Access System

    NASA Astrophysics Data System (ADS)

    Giriprakash, P.

    2011-01-01

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source software and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. A major new version of Mercury was developed during 2007 and released in early 2008. This new version provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, support for RSS delivery of search results, and ready customization to meet the needs of the multiple projects which use Mercury. For the end users, Mercury provides a single portal to very quickly search for data and information contained in disparate data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow ! the users to perform simple, fielded, spatial and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data.

  6. Waste Isolation Pilot Plant (WIPP) Waste Information System (Public Access)

    DOE Data Explorer

    The Waste Isolation Pilot Plant (WIPP) is a DOE facility located in the desert outside Carlsbad, New Mexico. Its mission is to safely dispose of defense-related transuranic radioactive waste. Disposal ôroomsö are carved out of the Permian Salt Formation deep below the desertÆs surface. The WIPP Waste Information Service (WWIS) was established in accordance with an Agreement between the United States Department of Energy and the New Mexico Environment Department, dated February 11, 2005, Docket Number HWB 04-07 (CO). The service provides information the containers emplaced at WIPP and the waste products they hold. The public may query by shipment number, location of waste stream or location of the container after it is placed at WIPP, date placed, and Haz Codes or other information about the waste stream profiles. For example, choosing the waste stream identified as ID-SDA-SLUDGE reveals that it may contain more than 20 chemical waste products, including arsenic, spent halogenated solvents, potassium cyanide, and chloroform. The system then tells you each numbered container that has this kind of sludge. Container data is available within 14 days after the containerÆs emplacement in the WIPP Repository.

  7. Utilizing Fission Technology to Enable Rapid and Affordable Access to any Point in the Solar System

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Bonometti, Joe; Morton, Jeff; Hrbud, Ivana; Bitteker, Leo; VanDyke, Melissa; Godfroy, T.; Pedersen, K.; Dobson, C.; Patton, B.; Martin, J.; Chakrabarti, S.

    2000-01-01

    Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include bimodal nuclear thermal rockets, high specific energy propulsion systems, and pulsed fission propulsion systems. In-space propellant re-supply enhances the effective performance of all systems, but requires significant infrastructure development. Safe, timely, affordable utilization of first-generation space fission propulsion systems will enable the development of more advanced systems. First generation systems can build on over 45 years of US and international space fission system technology development to minimize cost.

  8. A High Speed Mobile Courier Data Access System That Processes Database Queries in Real-Time

    NASA Astrophysics Data System (ADS)

    Gatsheni, Barnabas Ndlovu; Mabizela, Zwelakhe

    A secure high-speed query processing mobile courier data access (MCDA) system for a Courier Company has been developed. This system uses the wireless networks in combination with wired networks for updating a live database at the courier centre in real-time by an offsite worker (the Courier). The system is protected by VPN based on IPsec. There is no system that we know of to date that performs the task for the courier as proposed in this paper.

  9. Fast Transit Access to the Outer Solar System

    NASA Astrophysics Data System (ADS)

    Squire, Jared; Bering, Edgar; Giambusso, Matthew; Carter, Mark; Ilin, Andrew; Diaz, Franklin R. Chang

    2015-11-01

    We explore the capability of a VASIMR® reusable probe “catapult” concept to send a 4000-5000 kg spacecraft to Jupiter on a Hohmann-like transfer orbit, arriving in just 36 months elapsed time. The VASIMR® performs a slingshot pass close to the Sun and uses the high level of available solar energy to produce a sustained burst of high thrust. Enough kinetic energy is provided to the probe to reach Jupiter orbit within 0.7-1.4 AU. The Catapult release the probe with enough speed to reach Jupiter in three years, and returns to Earth for another mission. This study identifies the important parameters in the probe ejector operation (power level, propellant mass, payload release point, distance of closest approach to the Sun), and scan these parameters to understand and optimize the capabilities of the proposed system. We assume that the Catapult and its payload begin at the Earth’s sphere of influence (SOI), and are coasting in the Earth’s orbit about the Sun. The VASIMR® engine’s power rating must match the peak power available when the spacecraft is closest to the Sun. The solar array is assumed to be a planar array rather than a concentrator since it will have to operate near the Sun, where a concentrator would overheat photovoltaic cells. The feasibility of not releasing the payload and using the VASIMR® to provide thrust for the duration of the transfer orbit will also be examined. In this scenario, the VASIMR® RF generators could serve double duty as radar RF sources.

  10. L-band and SHF multiple access schemes for the MSAT system

    NASA Technical Reports Server (NTRS)

    Razi, Michael; Shoamanesh, Alireza; Azarbar, Bahman

    1988-01-01

    The first generation of the Canadian Mobile Satellite (MSAT) system, planned to be operational in the early 1990s, will provide voice and data services to land, aeronautical, and maritime mobile terminals within the Canadian land mass and its territorial waters. The system will be managed by a centralized Demand Assignment Multiple Access (DAMA) control system. Users will request a communication channel by communicating with the DAMA Control System (DCS) via the appropriate signalling channels. Several access techniques for both L-band and SHF signalling channels have been investigated. For the L-band, Slotted Aloha (SA) and Reservation Aloha (RA), combined with a token scheme, are discussed here. The results of Telesat studies to date indicate that SA, when combined with token scheme, provides the most efficient access and resource management tool in a mobile propagation environment. For SHF signalling channels, slim time division multiple access (TDMA) and SA have been considered as the most suitable candidate schemes. In view of the operational environment of the SHF links, provision of a very short channel access delay and a relatively high packet success rate are highly desirable. Studies carried out generally favor slim-TDMA as the most suitable approach for SHF signalling channels.

  11. Performance Evaluation of Virtualization Techniques for Control and Access of Storage Systems in Data Center Applications

    NASA Astrophysics Data System (ADS)

    Ahmadi, Mohammad Reza

    2013-09-01

    Virtualization is a new technology that creates virtual environments based on the existing physical resources. This article evaluates effect of virtualization techniques on control servers and access method in storage systems [1, 2]. In control server virtualization, we have presented a tile based evaluation based on heterogeneous workloads to compare several key parameters and demonstrate effectiveness of virtualization techniques. Moreover, we have evaluated the virtualized model using VMotion techniques and maximum consolidation. In access method, we have prepared three different scenarios using direct, semi-virtual, and virtual attachment models. We have evaluated the proposed models with several workloads including OLTP database, data streaming, file server, web server, etc. Results of evaluation for different criteria confirm that server virtualization technique has high throughput and CPU usage as well as good performance with noticeable agility. Also virtual technique is a successful alternative for accessing to the storage systems especially in large capacity systems. This technique can therefore be an effective solution for expansion of storage area and reduction of access time. Results of different evaluation and measurements demonstrate that the virtualization in control server and full virtual access provide better performance and more agility as well as more utilization in the systems and improve business continuity plan.

  12. Event-Driven Random-Access-Windowing CCD Imaging System

    NASA Technical Reports Server (NTRS)

    Monacos, Steve; Portillo, Angel; Ortiz, Gerardo; Alexander, James; Lam, Raymond; Liu, William

    2004-01-01

    A charge-coupled-device (CCD) based high-speed imaging system, called a realtime, event-driven (RARE) camera, is undergoing development. This camera is capable of readout from multiple subwindows [also known as regions of interest (ROIs)] within the CCD field of view. Both the sizes and the locations of the ROIs can be controlled in real time and can be changed at the camera frame rate. The predecessor of this camera was described in High-Frame-Rate CCD Camera Having Subwindow Capability (NPO- 30564) NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 26. The architecture of the prior camera requires tight coupling between camera control logic and an external host computer that provides commands for camera operation and processes pixels from the camera. This tight coupling limits the attainable frame rate and functionality of the camera. The design of the present camera loosens this coupling to increase the achievable frame rate and functionality. From a host computer perspective, the readout operation in the prior camera was defined on a per-line basis; in this camera, it is defined on a per-ROI basis. In addition, the camera includes internal timing circuitry. This combination of features enables real-time, event-driven operation for adaptive control of the camera. Hence, this camera is well suited for applications requiring autonomous control of multiple ROIs to track multiple targets moving throughout the CCD field of view. Additionally, by eliminating the need for control intervention by the host computer during the pixel readout, the present design reduces ROI-readout times to attain higher frame rates. This camera (see figure) includes an imager card consisting of a commercial CCD imager and two signal-processor chips. The imager card converts transistor/ transistor-logic (TTL)-level signals from a field programmable gate array (FPGA) controller card. These signals are transmitted to the imager card via a low-voltage differential signaling (LVDS) cable

  13. Vascular Access System for Continuous Arterial Infusion of a Protease Inhibitor in Acute Necrotizing Pancreatitis

    SciTech Connect

    Ganaha, Fumikiyo; Yamada, Tetsuhisa; Yorozu, Naoya; Ujita, Masuo; Irie, Takeo; Fukuda, Yasushi; Fukuda, Kunihiko; Tada, Shimpei

    1999-09-15

    We used a vascular access system (VAS) for continuous arterial infusion (CAI) of a protease inhibitor in two patients with acute necrotizing pancreatitis. The infusion catheter was placed into the dorsal pancreatic artery in the first patient and into the gastroduodenal artery in the second, via a femoral artery approach. An implantable port was then connected to the catheter and was secured in a subcutaneous pocket prepared in the right lower abdomen. No complications related to the VAS were encountered. This system provided safe and uncontaminated vascular access for successful CAI for acute pancreatitis.

  14. An efficient key-management scheme for hierarchical access control in e-medicine system.

    PubMed

    Wu, Shuhua; Chen, Kefei

    2012-08-01

    In e-medicine system, the sharing of patients' medical histories scattered among medical institutions through the Internet is highly desirable. The most immediate cryptographic need certainly is an efficient key management method to solve dynamic access problems in a user hierarchy. In this paper, we propose a practical solution for dynamic access problem in a user hierarchy based on hybrid cryptosystems. When compared with Nikooghadam et al.'s scheme proposed most recently, the time complexity and the required storage space is reduced significantly. Moreover, it provides provable security, and is easy to implement. Therefore, our scheme is more suitable for e-medicine system.

  15. Improving Access to EOSDIS Data and Services by a User Registration System

    NASA Astrophysics Data System (ADS)

    Smith, P.; Mitchell, A.; Farley, J. D.; Murphy, K. J.; Nakamura, E.

    2011-12-01

    As NASA's Earth Observing System Data and Information System (EOSDIS) systems have evolved over the years, most of the EOSDIS data are now available to users via anonymous on-line access. Although the changes have improved the dissemination efficiency of earth science data, the anonymous access has made it difficult to characterize users, capture metrics on the value of EOSDIS and provide customized services that benefit users. As the number of web-based applications continues to grow, data centers and application providers have implemented their own user registration systems and provided new tools and interfaces for their registered users. This has led to the creation of independent registration systems for accessing data and interacting with online tools and services. The user profile information maintained at each of these registration systems is not consistent and the registration enforcement varies by system as well. This problem is in no way unique to EOSDIS and represents a general challenge to the distributed computing community. In a study done in 2007*, the average user has approximately 7 passwords for about 25 accounts and enters a password 8 times a day. These numbers have only increased in the last three years. A consolidation of registration systems into an EOSDIS wide User Registration System (URS) presents an opportunity to improve the user experience through simplification of user registration and profile management. Users will be able to register once at a central location and gain basic access to publicly available EOSDIS data or services hosted at each of the data centers, including accessing tools & data that cannot fully interoperate without user identification. This single source of user profile information is simple for the user to update, and allows Data Center staff to seamlessly continue to provide account services. The Data Centers will offer new services such as providing targeted notifications of changes to data and service

  16. An Intelligent System Proposal for Improving the Safety and Accessibility of Public Transit by Highway.

    PubMed

    García, Carmelo R; Quesada-Arencibia, Alexis; Cristóbal, Teresa; Padrón, Gabino; Pérez, Ricardo; Alayón, Francisco

    2015-08-18

    The development of public transit systems that are accessible and safe for everyone, including people with special needs, is an objective that is justified from the civic and economic points of view. Unfortunately, public transit services are conceived for people who do not have reduced physical or cognitive abilities. In this paper, we present an intelligent public transit system by highway with the goal of facilitating access and improving the safety of public transit for persons with special needs. The system is deployed using components that are commonly available in transport infrastructure, e.g., sensors, mobile communications systems, and positioning systems. In addition, the system can operate in non-urban transport contexts, e.g., isolated rural areas, where the availability of basic infrastructure, such as electricity and communications infrastructures, is not always guaranteed. To construct the system, the principles and techniques of Ubiquitous Computing and Ambient Intelligence have been employed. To illustrate the utility of the system, two cases of services rendered by the system are described: the first case involves a surveillance system to guarantee accessibility at bus stops; the second case involves a route assistant for blind people.

  17. An Intelligent System Proposal for Improving the Safety and Accessibility of Public Transit by Highway

    PubMed Central

    García, Carmelo R.; Quesada-Arencibia, Alexis; Cristóbal, Teresa; Padrón, Gabino; Pérez, Ricardo; Alayón, Francisco

    2015-01-01

    The development of public transit systems that are accessible and safe for everyone, including people with special needs, is an objective that is justified from the civic and economic points of view. Unfortunately, public transit services are conceived for people who do not have reduced physical or cognitive abilities. In this paper, we present an intelligent public transit system by highway with the goal of facilitating access and improving the safety of public transit for persons with special needs. The system is deployed using components that are commonly available in transport infrastructure, e.g., sensors, mobile communications systems, and positioning systems. In addition, the system can operate in non-urban transport contexts, e.g., isolated rural areas, where the availability of basic infrastructure, such as electricity and communications infrastructures, is not always guaranteed. To construct the system, the principles and techniques of Ubiquitous Computing and Ambient Intelligence have been employed. To illustrate the utility of the system, two cases of services rendered by the system are described: the first case involves a surveillance system to guarantee accessibility at bus stops; the second case involves a route assistant for blind people. PMID:26295234

  18. Using geographic information system tools to improve access to MS specialty care in Veterans Health Administration.

    PubMed

    Culpepper, William J; Cowper-Ripley, Diane; Litt, Eric R; McDowell, Tzu-Yun; Hoffman, Paul M

    2010-01-01

    Access to appropriate and timely healthcare is critical to the overall health and well-being of patients with chronic diseases. In this study, we used geographic information system (GIS) tools to map Veterans Health Administration (VHA) patients with multiple sclerosis (MS) and their access to MS specialty care. We created six travel-time bands around VHA facilities with MS specialty care and calculated the number of VHA patients with MS who resided in each time band and the number of patients who lived more than 2 hours from the nearest specialty clinic in fiscal year 2007. We demonstrate the utility of using GIS tools in decision-making by providing three examples of how patients' access to care is affected when additional specialty clinics are added. The mapping technique used in this study provides a powerful and valuable tool for policy and planning personnel who are evaluating how to address underserved populations and areas within the VHA healthcare system. PMID:20848371

  19. Using geographic information system tools to improve access to MS specialty care in Veterans Health Administration.

    PubMed

    Culpepper, William J; Cowper-Ripley, Diane; Litt, Eric R; McDowell, Tzu-Yun; Hoffman, Paul M

    2010-01-01

    Access to appropriate and timely healthcare is critical to the overall health and well-being of patients with chronic diseases. In this study, we used geographic information system (GIS) tools to map Veterans Health Administration (VHA) patients with multiple sclerosis (MS) and their access to MS specialty care. We created six travel-time bands around VHA facilities with MS specialty care and calculated the number of VHA patients with MS who resided in each time band and the number of patients who lived more than 2 hours from the nearest specialty clinic in fiscal year 2007. We demonstrate the utility of using GIS tools in decision-making by providing three examples of how patients' access to care is affected when additional specialty clinics are added. The mapping technique used in this study provides a powerful and valuable tool for policy and planning personnel who are evaluating how to address underserved populations and areas within the VHA healthcare system.

  20. Systemic fibrinolysis through intraosseous vascular access in ST-segment elevation myocardial infarction.

    PubMed

    Ruiz-Hornillos, Pedro José; Martínez-Cámara, Fernando; Elizondo, Mercedes; Jiménez-Fraile, José Antonio; Del Mar Alonso-Sánchez, Maria; Galán, Dolores; García-Rubira, Juan Carlos; Macaya, Carlos; Ibanez, Borja

    2011-06-01

    In emergency situations, intraosseous cannulation represents an alternative route of vascular access when peripheral vein insertion is difficult. We present the first documented case of intraosseous systemic fibrinolysis in a patient with ST-segment elevation myocardial infarction. In this case, repetitive episodes of ventricular fibrillation occurred soon after first contact with emergency care providers. Given that the patient had difficult peripheral venous access, an intraosseous catheter was inserted. Fibrinolytics and antiarrhythmic drugs were administered though this line, resulting in resolution of coronary ischemia and electrical instability, without complications. Intraosseous cannulation represents a novel route for administration of systemic fibrinolysis in cases of difficult peripheral venous access in the out-of-hospital setting. PMID:20947209

  1. Propagation Characteristics in an Underground Shopping Area for 5GHz-band Wireless Access Systems

    NASA Astrophysics Data System (ADS)

    Itokawa, Kiyohiko; Kita, Naoki; Sato, Akio; Matsue, Hideaki; Mori, Daisuke; Watanabe, Hironobu

    5-GHz band wireless access systems, such as the RLAN (Radio Local Area Network) system of IEEE802.11a, HiperLAN/2, HiSWANa and AWA, are developed and provide transmission rates over 20 Mbps for indoor use. Those 5-GHz access systems are expected to extend service areas from the office to the so-called “hot-spot" in public areas. Underground shopping malls are one of the anticipated service areas for such a nomadic wireless access service. Broadband propagation characteristics are required for radio zone design in an underground mall environment despite previous results obtained by narrow band measurements. This paper presents results of an experimental study on the propagation characteristics for broadband wireless access systems in an underground mall environment. First, broadband propagation path loss is measured and formulated considering human body shadowing. A ray trace simulation is used to clarify the basic propagation mechanism in such a closed environment. Next, a distance dependency of the delay spread during a crowded time period, rush hour, is found to be at most 65 nsec, which is under the permitted maximum value of the present 5-GHz systems. Finally, above propagation characteristics support the result of transmission test carried out by using AWA equipment.

  2. OASIS: A Data Fusion System Optimized for Access to Distributed Archives

    NASA Astrophysics Data System (ADS)

    Berriman, G. B.; Kong, M.; Good, J. C.

    2002-05-01

    The On-Line Archive Science Information Services (OASIS) is accessible as a java applet through the NASA/IPAC Infrared Science Archive home page. It uses Geographical Information System (GIS) technology to provide data fusion and interaction services for astronomers. These services include the ability to process and display arbitrarily large image files, and user-controlled contouring, overlay regeneration and multi-table/image interactions. OASIS has been optimized for access to distributed archives and data sets. Its second release (June 2002) provides a mechanism that enables access to OASIS from "third-party" services and data providers. That is, any data provider who creates a query form to an archive containing a collection of data (images, catalogs, spectra) can direct the result files from the query into OASIS. Similarly, data providers who serve links to datasets or remote services on a web page can access all of these data with one instance of OASIS. In this was any data or service provider is given access to the full suite of capabilites of OASIS. We illustrate the "third-party" access feature with two examples: queries to the high-energy image datasets accessible from GSFC SkyView, and links to data that are returned from a target-based query to the NASA Extragalactic Database (NED). The second release of OASIS also includes a file-transfer manager that reports the status of multiple data downloads from remote sources to the client machine. It is a prototype for a request management system that will ultimately control and manage compute-intensive jobs submitted through OASIS to computing grids, such as request for large scale image mosaics and bulk statistical analysis.

  3. Ver-i-Fus: an integrated access control and information monitoring and management system

    NASA Astrophysics Data System (ADS)

    Thomopoulos, Stelios C.; Reisman, James G.; Papelis, Yiannis E.

    1997-01-01

    This paper describes the Ver-i-Fus Integrated Access Control and Information Monitoring and Management (IAC-I2M) system that INTELNET Inc. has developed. The Ver-i-Fus IAC-I2M system has been designed to meet the most stringent security and information monitoring requirements while allowing two- way communication between the user and the system. The systems offers a flexible interface that permits to integrate practically any sensing device, or combination of sensing devices, including a live-scan fingerprint reader, thus providing biometrics verification for enhanced security. Different configurations of the system provide solutions to different sets of access control problems. The re-configurable hardware interface, tied together with biometrics verification and a flexible interface that allows to integrate Ver-i-Fus with an MIS, provide an integrated solution to security, time and attendance, labor monitoring, production monitoring, and payroll applications.

  4. Interactive distance education service (IDES) using the Centralized Access Node System (CANS)

    NASA Astrophysics Data System (ADS)

    Moon, Phil J.; Choi, Mun K.; Jun, Mun S.; Lee, Chul H.

    1995-02-01

    The successes of B-ISDN project depend on attractive application services. Thus, it is very important to analyze application services which users desire, and to study the customer access network for applications. Especially, because the cost of the constructions for the customer access network need high, it is very important to configure this network economically and effectively. We recognize the importance how to provide B-ISDN application services and to configure the customer access network. This paper describes the Interactive Distance Education Service (IDES) requirements in the user and network aspects. The requirements include the service definition, reference configuration, procedure and Quality Of Service. And also this paper proposes the configuration of customer access network for providing IDES using the Centralized Access Node system which is a kind of the B-NT system. There are many applications area in IDES, we describe the three scenarios--for rural area, between the major and minor campus and for joint education including the university, research institute and enterprise.

  5. Improving Higher Education Access and Persistence: New Directions from a "Systems" Perspective.

    ERIC Educational Resources Information Center

    Stampen, Jacob O.; Hansen, W. Lee

    1999-01-01

    Illustrates a "systems approach," based on the quality deployment function, for examining the direct and interaction effects of multiple solutions aimed at improving access to college and student persistence. The high leverage solutions emerging from this study call for the improvement of academic achievement and schools for grades K-12. (SLD)

  6. Design mobile satellite system architecture as an integral part of the cellular access digital network

    NASA Technical Reports Server (NTRS)

    Chien, E. S. K.; Marinho, J. A.; Russell, J. E., Sr.

    1988-01-01

    The Cellular Access Digital Network (CADN) is the access vehicle through which cellular technology is brought into the mainstream of the evolving integrated telecommunications network. Beyond the integrated end-to-end digital access and per call network services provisioning of the Integrated Services Digital Network (ISDN), the CADN engenders the added capability of mobility freedom via wireless access. One key element of the CADN network architecture is the standard user to network interface that is independent of RF transmission technology. Since the Mobile Satellite System (MSS) is envisioned to not only complement but also enhance the capabilities of the terrestrial cellular telecommunications network, compatibility and interoperability between terrestrial cellular and mobile satellite systems are vitally important to provide an integrated moving telecommunications network of the future. From a network standpoint, there exist very strong commonalities between the terrestrial cellular system and the mobile satellite system. Therefore, the MSS architecture should be designed as an integral part of the CADN. This paper describes the concept of the CADN, the functional architecture of the MSS, and the user-network interface signaling protocols.

  7. Computer-Based Systems for Increasing Information Access to School Media Center Materials. Final Report.

    ERIC Educational Resources Information Center

    Hines, Theodore C.; And Others

    The project presented here explored the possibility of using computer-based systems to increase information access to non-text children's materials at the pre-school through elementary (6th grade) school levels. This final report includes an indicative summary as well as ten separate papers that describe a range of applications of proven computer…

  8. Health Service Access across Racial/Ethnic Groups of Children in the Child Welfare System

    ERIC Educational Resources Information Center

    Wells, Rebecca; Hillemeier, Marianne M.; Bai, Yu; Belue, Rhonda

    2009-01-01

    Objective: This study examined health service access among children of different racial/ethnic groups in the child welfare system in an attempt to identify and explain disparities. Methods: Data were from the National Survey of Child and Adolescent Well-Being (NSCAW). N for descriptive statistics = 2,505. N for multiple regression model = 537.…

  9. 48 CFR 504.602-71 - Federal Procurement Data System-Public access to data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Procurement Data System—Public access to data. (a) The FPDS database. The General Services Administration awarded a contract for creation and operation of the Federal Procurement Data System (FPDS) database. That database includes information reported by departments and agencies as required by Federal...

  10. 48 CFR 504.605-70 - Federal Procurement Data System-Public access to data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Procurement Data System—Public access to data. (a) The FPDS database. The General Services Administration awarded a contract for creation and operation of the Federal Procurement Data System (FPDS) database. That database includes information reported by departments and agencies as required by FAR subpart 4.6. One...

  11. 48 CFR 504.602-71 - Federal Procurement Data System-Public access to data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Procurement Data System—Public access to data. (a) The FPDS database. The General Services Administration awarded a contract for creation and operation of the Federal Procurement Data System (FPDS) database. That database includes information reported by departments and agencies as required by Federal...

  12. 48 CFR 504.605-70 - Federal Procurement Data System-Public access to data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Procurement Data System—Public access to data. (a) The FPDS database. The General Services Administration awarded a contract for creation and operation of the Federal Procurement Data System (FPDS) database. That database includes information reported by departments and agencies as required by FAR subpart 4.6. One...

  13. 48 CFR 504.605-70 - Federal Procurement Data System-Public access to data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Procurement Data System—Public access to data. (a) The FPDS database. The General Services Administration awarded a contract for creation and operation of the Federal Procurement Data System (FPDS) database. That database includes information reported by departments and agencies as required by FAR subpart 4.6. One...

  14. 5 CFR 293.504 - Composition of, and access to, the Employee Medical File System.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., are part of the EMFS. The records maintained in the EMFS are part of a Governmentwide Privacy Act... employee are not required to be included as a record within the EMFS, under certain conditions to be..., may be included in the system. (b) Agencies must provide employees access to their own EMFS...

  15. Accessibility Evaluation of Online Learning Management System for Persons with Visual Impairment

    ERIC Educational Resources Information Center

    Suwannawut, Nantanoot

    2014-01-01

    Many academic institutions around the world are utilizing and investing in online learning management systems (LMS). While several research studies have examined the functionality of this type of technology, little attention has been paid to accessibility issues, in particular to the complex web-based interfaces for learners with disabilities,…

  16. 28 CFR 16.92 - Exemption of Environment and Natural Resources Division Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Exemption of Environment and Natural....92 Exemption of Environment and Natural Resources Division Systems—limited access. (a)(1) The...) Environment and Natural Resources Division Case and Related Files System, JUSTICE/ENRD-003. (ii) (2)...

  17. 28 CFR 16.92 - Exemption of Environment and Natural Resources Division Systems-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Exemption of Environment and Natural....92 Exemption of Environment and Natural Resources Division Systems—limited access. (a)(1) The...) Environment and Natural Resources Division Case and Related Files System, JUSTICE/ENRD-003. (ii) (2)...

  18. 28 CFR 16.77 - Exemption of U.S. Trustee Program System-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) U.S. Trustee Program Case Referral System, JUSTICE/UST-004. These exemptions apply to the extent...-limited access. 16.77 Section 16.77 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... involved in a certain investigation. Amendment of the records would interfere with ongoing criminal...

  19. 28 CFR 16.81 - Exemption of United States Attorneys Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Consumer Complaints (JUSTICE/USA-006). (4) Criminal Case Files (JUSTICE/USA-007). (5) Kline-District of..., Criminal Files (JUSTICE/USA-013). (9) Pre-trial Diversion Program Files (JUSTICE/USA-014). These exemptions... Systems-limited access. 16.81 Section 16.81 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION...

  20. 28 CFR 16.77 - Exemption of U.S. Trustee Program System-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) U.S. Trustee Program Case Referral System, JUSTICE/UST-004. These exemptions apply to the extent...-limited access. 16.77 Section 16.77 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... involved in a certain investigation. Amendment of the records would interfere with ongoing criminal...

  1. 28 CFR 16.80 - Exemption of Office of Professional Responsibility System-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Responsibility System-limited access. 16.80 Section 16.80 Judicial Administration DEPARTMENT OF JUSTICE...), (e)(5) and (8), (f) and (g): (1) Office of Professional Responsibility Record Index (JUSTICE/OPR-001... from 5 U.S.C. 552a(d). (1) Freedom of Information/Privacy Act (FOI/PA) Records (JUSTICE/OPR-002)....

  2. 28 CFR 16.80 - Exemption of Office of Professional Responsibility System-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Responsibility System-limited access. 16.80 Section 16.80 Judicial Administration DEPARTMENT OF JUSTICE...), (e)(5) and (8), (f) and (g): (1) Office of Professional Responsibility Record Index (JUSTICE/OPR-001... from 5 U.S.C. 552a(d). (1) Freedom of Information/Privacy Act (FOI/PA) Records (JUSTICE/OPR-002)....

  3. 28 CFR 16.81 - Exemption of United States Attorneys Systems-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Consumer Complaints (JUSTICE/USA-006). (4) Criminal Case Files (JUSTICE/USA-007). (5) Kline-District of..., Criminal Files (JUSTICE/USA-013). (9) Pre-trial Diversion Program Files (JUSTICE/USA-014). These exemptions... Systems-limited access. 16.81 Section 16.81 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION...

  4. 28 CFR 16.77 - Exemption of U.S. Trustee Program System-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) U.S. Trustee Program Case Referral System, JUSTICE/UST-004. These exemptions apply to the extent...-limited access. 16.77 Section 16.77 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... involved in a certain investigation. Amendment of the records would interfere with ongoing criminal...

  5. 28 CFR 16.81 - Exemption of United States Attorneys Systems-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Consumer Complaints (JUSTICE/USA-006). (4) Criminal Case Files (JUSTICE/USA-007). (5) Kline-District of..., Criminal Files (JUSTICE/USA-013). (9) Pre-trial Diversion Program Files (JUSTICE/USA-014). These exemptions... Systems-limited access. 16.81 Section 16.81 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION...

  6. 28 CFR 16.77 - Exemption of U.S. Trustee Program System-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) U.S. Trustee Program Case Referral System, JUSTICE/UST-004. These exemptions apply to the extent...-limited access. 16.77 Section 16.77 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... involved in a certain investigation. Amendment of the records would interfere with ongoing criminal...

  7. 28 CFR 16.80 - Exemption of Office of Professional Responsibility System-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Responsibility System-limited access. 16.80 Section 16.80 Judicial Administration DEPARTMENT OF JUSTICE...), (e)(5) and (8), (f) and (g): (1) Office of Professional Responsibility Record Index (JUSTICE/OPR-001... from 5 U.S.C. 552a(d). (1) Freedom of Information/Privacy Act (FOI/PA) Records (JUSTICE/OPR-002)....

  8. 28 CFR 16.80 - Exemption of Office of Professional Responsibility System-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Responsibility System-limited access. 16.80 Section 16.80 Judicial Administration DEPARTMENT OF JUSTICE...), (e)(5) and (8), (f) and (g): (1) Office of Professional Responsibility Record Index (JUSTICE/OPR-001... from 5 U.S.C. 552a(d). (1) Freedom of Information/Privacy Act (FOI/PA) Records (JUSTICE/OPR-002)....

  9. 28 CFR 16.80 - Exemption of Office of Professional Responsibility System-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Responsibility System-limited access. 16.80 Section 16.80 Judicial Administration DEPARTMENT OF JUSTICE...), (e)(5) and (8), (f) and (g): (1) Office of Professional Responsibility Record Index (JUSTICE/OPR-001... from 5 U.S.C. 552a(d). (1) Freedom of Information/Privacy Act (FOI/PA) Records (JUSTICE/OPR-002)....

  10. 28 CFR 16.77 - Exemption of U.S. Trustee Program System-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) U.S. Trustee Program Case Referral System, JUSTICE/UST-004. These exemptions apply to the extent...-limited access. 16.77 Section 16.77 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE... involved in a certain investigation. Amendment of the records would interfere with ongoing criminal...

  11. An Annotated and Cross-Referenced Bibliography on Computer Security and Access Control in Computer Systems.

    ERIC Educational Resources Information Center

    Bergart, Jeffrey G.; And Others

    This paper represents a careful study of published works on computer security and access control in computer systems. The study includes a selective annotated bibliography of some eighty-five important published results in the field and, based on these papers, analyzes the state of the art. In annotating these works, the authors try to be…

  12. 75 FR 47464 - Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... Copyright Office 37 CFR Part 201 Exemption to Prohibition on Circumvention of Copyright Protection Systems for Access Control Technologies AGENCY: Copyright Office, Library of Congress. ACTION: Final Rule; correction. SUMMARY: The Copyright Office makes a nonsubstantial correction to its regulation announcing...

  13. The Hardware Helper II: Finding the Right System for Accessing the Web.

    ERIC Educational Resources Information Center

    Jacso, Peter

    1997-01-01

    Examines the primary considerations in choosing a computer for Web access in a school setting: (1) Internet connection; (2) operating system; (3) processor and memory; (4) video subsystem; (5) audio; and (6) hard disk. Suggests having both a budget and a high-end personal computer. (AEF)

  14. Hacking Blackboard: Customizing Access to Library Resources through the Blackboard Course Management System

    ERIC Educational Resources Information Center

    Kellam, Lynda M.; Cox, Richard; Winkler, Hannah

    2009-01-01

    Academic libraries have long been trying to gain access to users through their favorite online spaces, such as social networking sites. In this article a project of the University of North Carolina at Greensboro's University Libraries, which integrated library resources with the campus course management system, Blackboard, is detailed. The main…

  15. 32 CFR 323.5 - Access to systems of records information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... processed in accordance with 32 CFR 310.18 and 310.19. (c) If an individual disagrees with the initial... (CONTINUED) PRIVACY PROGRAM DEFENSE LOGISTICS AGENCY PRIVACY PROGRAM § 323.5 Access to systems of records... Logistics Agency, ATTN: DGA, 8725 John J. Kingman Road, Suite 1644, Fort Belvoir, VA 22060-6221. Any...

  16. 32 CFR 323.5 - Access to systems of records information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... processed in accordance with 32 CFR 310.18 and 310.19. (c) If an individual disagrees with the initial... (CONTINUED) PRIVACY PROGRAM DEFENSE LOGISTICS AGENCY PRIVACY PROGRAM § 323.5 Access to systems of records... Logistics Agency, ATTN: DGA, 8725 John J. Kingman Road, Suite 1644, Fort Belvoir, VA 22060-6221. Any...

  17. 50 CFR 622.371 - Limited access system for commercial vessel permits for king mackerel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... vessel permits for king mackerel. 622.371 Section 622.371 Wildlife and Fisheries FISHERY CONSERVATION AND... Atlantic) § 622.371 Limited access system for commercial vessel permits for king mackerel. (a) No applications for additional commercial vessel permits for king mackerel will be accepted. Existing...

  18. 50 CFR 622.371 - Limited access system for commercial vessel permits for king mackerel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... vessel permits for king mackerel. 622.371 Section 622.371 Wildlife and Fisheries FISHERY CONSERVATION AND... Atlantic) § 622.371 Limited access system for commercial vessel permits for king mackerel. (a) No applications for additional commercial vessel permits for king mackerel will be accepted. Existing...

  19. 28 CFR 16.92 - Exemption of Environment and Natural Resources Division Systems-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Exemption of Environment and Natural....92 Exemption of Environment and Natural Resources Division Systems—limited access. (a)(1) The...) Environment and Natural Resources Division Case and Related Files System, JUSTICE/ENRD-003. (ii) (2)...

  20. 28 CFR 16.92 - Exemption of Environment and Natural Resources Division Systems-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Exemption of Environment and Natural....92 Exemption of Environment and Natural Resources Division Systems—limited access. (a)(1) The...) Environment and Natural Resources Division Case and Related Files System, JUSTICE/ENRD-003. (ii) (2)...

  1. 28 CFR 16.98 - Exemption of the Drug Enforcement Administration (DEA) Systems-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Exemption of the Drug Enforcement... PRODUCTION OR DISCLOSURE OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.98 Exemption of the Drug Enforcement Administration (DEA) Systems—limited access. (a) The...

  2. 28 CFR 16.98 - Exemption of the Drug Enforcement Administration (DEA) Systems-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Exemption of the Drug Enforcement... PRODUCTION OR DISCLOSURE OF MATERIAL OR INFORMATION Exemption of Records Systems Under the Privacy Act § 16.98 Exemption of the Drug Enforcement Administration (DEA) Systems—limited access. (a) The...

  3. Accessing the Health Care Financing System: A Resource Guide for Local Education Agencies. Bulletin No. 91298.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Public Instruction, Madison.

    This guide is intended to assist Wisconsin school districts in accessing the health care financing system as a means of supporting specialized services. Topics covered include: determination of a local education agency's potential for third-party covered services; the need to become a certified provider dependent upon the funding source;…

  4. Access to Corporate Information Systems: Datafiles, Classified Documents, and Information Resources.

    ERIC Educational Resources Information Center

    Baumgartner, Kurt O.; And Others

    1988-01-01

    Three articles discuss aspects of corporate information systems: (1) "Packet Switching Networks: Worldwide Access to Corporate Datafiles" (Kurt O. Baumgartner); "Classified Documents in the Corporate Library" (Patricia M. Shores); and "From Library to Information Center: Case Studies in the Evolution of Corporate Information Resources" (Eva M.…

  5. A Needs Assessment of the Accessibility of Distance Education in the California Community College System. Part II: Costs and Promising Practices Associated with Making Distance Education Courses Accessible

    ERIC Educational Resources Information Center

    Farr, Beverly; Studier, Carol; Sipes, Laurel; Coombs, Norman

    2009-01-01

    As the number of online distance education (DE) courses mushrooms in the California community college system, the need to address the accessibility of these courses becomes more and more urgent. With this in mind, the California Community College System Office (CCCSO) retained MPR Associates, Inc. to complete a needs assessment to help determine…

  6. Automated biometric access control system for two-man-rule enforcement

    SciTech Connect

    Holmes, J.P.; Maxwell, R.L. ); Henderson, R.W. )

    1991-01-01

    This paper describes a limited access control system for nuclear facilities which makes use of the eye retinal identity verifier to control the passage of personnel into and out of one or a group of security controlled working areas. This access control system requires no keys, cards or credentials. The user simply enters his Personal Identification Number (PIN) and takes an eye reading to request passage. The PIN does not have to be kept secret. The system then relies on biometric identity verification of the user, along with other system information, to make the decision of whether or not to unlock the door. It also enforces multiple zones control with personnel tracking and the two-man-rule.

  7. Necessary security mechanisms in a PACS DICOM access system with web technology.

    PubMed

    Vázquez-Naya, José; Loureiro, Javier; Calle, Julián; Vidal, Jorge; Sierra, Alejandro

    2002-01-01

    The evolution in information and telecommunication technologies has allowed the development of systems that use the Internet infrastructure and Web technology to remotely access a hospital's picture archiving and communication system (PACS). However, one of the main problems in the construction of this type of system is the development of mechanisms that guarantee the security of the medical data that are being consulted. Most countries have specific norms for the protection of such medical data. This work describes security mechanisms that are developed in an access system to PACS DICOM with Web technology and comply with the Spanish legislation concerning the protection of medical data. The proposed security mechanisms are flexible, they leave room for the definition of security policies adjusted to the needs of each particular organization and they can be adapted to comply with new or foreign norms.

  8. A simple, effective media access protocol system for integrated, high data rate networks

    NASA Technical Reports Server (NTRS)

    Foudriat, E. C.; Maly, K.; Overstreet, C. M.; Khanna, S.; Zhang, L.

    1992-01-01

    The operation and performance of a dual media access protocol for integrated, gigabit networks are described. Unlike other dual protocols, each protocol supports a different class of traffic. The Carrier Sensed Multiple Access-Ring Network (CSMA/RN) protocol and the Circulating Reservation Packet (CRP) protocol support asynchronous and synchronous traffic, respectively. The two protocols operate with minimal impact upon each other. Performance information demonstrates that they support a complete range of integrated traffic loads, do not require call setup/termination or a special node for synchronous traffic control, and provide effective pre-use and recovery. The CRP also provides guaranteed access and fairness control for the asynchronous system. The paper demonstrates that the CSMA-CRP system fulfills many of the requirements for gigabit LAN-MAN networks most effectively and simply. To accomplish this, CSMA-CRP features are compared against similar ring and bus systems, such as Cambridge Fast Ring, Metaring, Cyclic Reservation Multiple Access, and Distributed Dual Queue Data Bus (DQDB).

  9. Difficulties experienced by trans people in accessing the Unified Health System.

    PubMed

    Rocon, Pablo Cardozo; Rodrigues, Alexsandro; Zamboni, Jésio; Pedrini, Mateus Dias

    2016-08-01

    The objective of this study was to discuss the difficulties of trans people living in the metropolitan region of Greater Vitória, Espírito Santo, Brazil, in accessing the health services of the Unified Health System (Sistema Único de Saúde - SUS). We used a qualitative approach through semi-structured interviews with 15 trans people. The results point to disrespect toward the adopted name, discrimination, and the diagnosis required for the gender reassignment process as major limitations to accessing the healthcare system. The diagnosis helps hide the responsibility of heteronormativity and gender binarism in the social marginalization of trans people. It is concluded that it is necessary to review the issue of diagnosis, given that the existence of a prior pathology is not required to access the SUS. It is important to develop educational programmes and permanent campaigns concerning the right to access the healthcare system free from discrimination and to use the adopted name. PMID:27557024

  10. Universal filtered multi-carrier system for asynchronous uplink transmission in optical access network

    NASA Astrophysics Data System (ADS)

    Kang, Soo-Min; Kim, Chang-Hun; Han, Sang-Kook

    2016-02-01

    In passive optical network (PON), orthogonal frequency division multiplexing (OFDM) has been studied actively due to its advantages such as high spectra efficiency (SE), dynamic resource allocation in time or frequency domain, and dispersion robustness. However, orthogonal frequency division multiple access (OFDMA)-PON requires tight synchronization among multiple access signals. If not, frequency orthogonality could not be maintained. Also its sidelobe causes inter-channel interference (ICI) to adjacent channel. To prevent ICI caused by high sidelobes, guard band (GB) is usually used which degrades SE. Thus, OFDMA-PON is not suitable for asynchronous uplink transmission in optical access network. In this paper, we propose intensity modulation/direct detection (IM/DD) based universal filtered multi-carrier (UFMC) PON for asynchronous multiple access. The UFMC uses subband filtering to subsets of subcarriers. Since it reduces sidelobe of each subband by applying subband filtering, it could achieve better performance compared to OFDM. For the experimental demonstration, different sample delay was applied to subbands to implement asynchronous transmission condition. As a result, time synchronization robustness of UFMC was verified in asynchronous multiple access system.

  11. Catheter Securement Systems for Peripherally Inserted and Nontunneled Central Vascular Access Devices

    PubMed Central

    Krenik, Karen M.; Smith, Graham E.

    2016-01-01

    Sutureless catheter securement systems are intended to eliminate risks associated with sutures. The clinical acceptability of a novel system was investigated compared with the current method of securement for peripherally inserted central catheters (19 facilities using StatLock or sutures) or nontunneled central vascular access devices (3 facilities using StatLock or sutures or HubGuard + Sorbaview Shield). More than 94% of respondents rated the novel system as same, better, or much better than their current product. More than 82% of respondents were willing to replace their current system with the new one. PMID:27379679

  12. Multiple-access phased array antenna simulator for a digital beam forming system investigation

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Yu, John; Walton, Joanne C.; Perl, Thomas D.; Andro, Monty; Alexovich, Robert E.

    1992-01-01

    Future versions of data relay satellite systems are currently being planned by NASA. Being given consideration for implementation are on-board digital beamforming techniques which will allow multiple users to simultaneously access a single S-band phased array antenna system. To investigate the potential performance of such a system, a laboratory simulator has been developed at NASA's Lewis Research Center. This paper describes the system simulator, and in particular, the requirements, design, and performance of a key subsystem, the phased array antenna simulator, which provides realistic inputs to the digital processor including multiple signals, noise, and nonlinearities.

  13. Convergence study of various non-quadratic adaptive algorithms in the equalization of impulsive DS-CDMA channel

    NASA Astrophysics Data System (ADS)

    Jimaa, Shihab A.; Jadah, Mohamed E.

    2005-10-01

    This paper investigates the performance of using various non-quadratic adaptive algorithms in the adaptation of a non-linear receiver, coupled with a second-order phase tracking subsystem, for asynchronous DS-CDMA communication system impaired by double-spread multipath channel and Gaussian mixture impulsive noise. These algorithms are the lower order (where the power of the cost function is lower than 2), the least-mean mixed norm (where a mixed-norm function is introduced, which combines the LMS and the LMF functions), and the least mean square-fourth switching (where this algorithm switches between LMS and LMF depending on the value of the error). The non-linear receiver comprises feed-forward filter (FFF), feedback filter (FBF), and an equalizer/second order phase locked loop (PLL). The investigations study the effect of using the proposed algorithms on the performance of the non-linear receiver in terms of the mean-square error (MSE) and bit-error-rate (BER). Computer simulation results indicate that the least-mean mixed proposed receiver's algorithm gives the fastest convergence rate and similar BER performance, in comparison with the NLMS adaptive receiver. Furthermore, extensive computer simulation tests have been carried out to determine the optimum values of the step-size, the power of the cost function, and the adaptation parameter of the proposed algorithms. Results show that the optimum values of the step-size for the lower-order, least-mean square fourth, least-mean mixed norm, and the NLMS algorithms are 5x10 -4, 10 -6, 5x10 -4, and 0.01, respectively. The optimum value of the power of the lower-order algorithm is 1.9 and the optimum value of the adaptation parameter of the least-mean mixed algorithm is 0.9.

  14. Interoperable Access to Near Real Time Ocean Observations with the Observing System Monitoring Center

    NASA Astrophysics Data System (ADS)

    O'Brien, K.; Hankin, S.; Mendelssohn, R.; Simons, R.; Smith, B.; Kern, K. J.

    2013-12-01

    The Observing System Monitoring Center (OSMC), a project funded by the National Oceanic and Atmospheric Administration's Climate Observations Division (COD), exists to join the discrete 'networks' of In Situ ocean observing platforms -- ships, surface floats, profiling floats, tide gauges, etc. - into a single, integrated system. The OSMC is addressing this goal through capabilities in three areas focusing on the needs of specific user groups: 1) it provides real time monitoring of the integrated observing system assets to assist management in optimizing the cost-effectiveness of the system for the assessment of climate variables; 2) it makes the stream of real time data coming from the observing system available to scientific end users into an easy-to-use form; and 3) in the future, it will unify the delayed-mode data from platform-focused data assembly centers into a standards- based distributed system that is readily accessible to interested users from the science and education communities. In this presentation, we will be focusing on the efforts of the OSMC to provide interoperable access to the near real time data stream that is available via the Global Telecommunications System (GTS). This is a very rich data source, and includes data from nearly all of the oceanographic platforms that are actively observing. We will discuss how the data is being served out using a number of widely used 'web services' (including OPeNDAP and SOS) and downloadable file formats (KML, csv, xls, netCDF), so that it can be accessed in web browsers and popular desktop analysis tools. We will also be discussing our use of the Environmental Research Division's Data Access Program (ERDDAP), available from NOAA/NMFS, which has allowed us to achieve our goals of serving the near real time data. From an interoperability perspective, it's important to note that access to the this stream of data is not just for humans, but also for machine-to-machine requests. We'll also delve into how we

  15. Discovery of abundant, accessible hydrocarbons nearly everywhere in the solar system

    SciTech Connect

    Zuppero, A.

    1996-05-01

    analysis of the data gathered during the Comet Halley encounter during 1987 resulted in a body of literature asserting that all comets contain substantial percentages of hydrocarbon solids. These solids appear to have a strong similarity to petrochemicals. Arguments are made that the amount of hydrocarbon material in the accessible comets of the inner Solar system can substantially exceed the known reserves of hydrocarbons on Earth. An example is given of at least one conceptually simple method to use comet material as feedstock for space transportation schemes that can move masses through the solar system comparable to the mass carried by oil supertankers. The presentation concludes we need to send prospecting and assay probes to a sampling of the accessible comets to determine the amount of hydrocarbons and the form and location of materials needed for space transportation systems.

  16. Multiple Access Schemes for Lunar Missions

    NASA Technical Reports Server (NTRS)

    Deutsch, Leslie; Hamkins, Jon; Stocklin, Frank J.

    2010-01-01

    Two years ago, the NASA Coding, Modulation, and Link Protocol (CMLP) study was completed. The study, led by the authors of this paper, recommended codes, modulation schemes, and desired attributes of link protocols for all space communication links in NASA's future space architecture. Portions of the NASA CMLP team were reassembled to resolve one open issue: the use of multiple access (MA) communication from the lunar surface. The CMLP-MA team analyzed and simulated two candidate multiple access schemes that were identified in the original CMLP study: Code Division MA (CDMA) and Frequency Division MA (FDMA) based on a bandwidth-efficient Continuous Phase Modulation (CPM) with a superimposed Pseudo-Noise (PN) ranging signal (CPM/PN). This paper summarizes the results of the analysis and simulation of the CMLP-MA study and describes the final recommendations.

  17. Study of spread spectrum multiple access systems for satellite communications with overlay on current services

    NASA Technical Reports Server (NTRS)

    Ha, Tri T.; Pratt, Timothy

    1989-01-01

    The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel.

  18. Study of spread spectrum multiple access systems for satellite communications with overlay on current services

    NASA Astrophysics Data System (ADS)

    Ha, Tri T.; Pratt, Timothy

    1989-05-01

    The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel.

  19. Return Migrants’ Experience of Access to Care in Corrupt Healthcare Systems: The Bosnian Example

    PubMed Central

    Neerup Handlos, Line; Fog Olwig, Karen; Bygbjerg, Ib Christian; Norredam, Marie

    2016-01-01

    Equal and universal access to healthcare services is a core priority for a just health system. A key societal determinant seen to create inequality in access to healthcare is corruption in the healthcare system. How return migrants’ access to healthcare is affected by corruption is largely unstudied, even though return migrants may be particularly vulnerable to problems related to corruption due to their period of absence from their country of origin. This article investigates how corruption in the healthcare sector affects access to healthcare for refugees who repatriated to Bosnia, a country with a high level of corruption, from Denmark, a country with a low level of corruption. The study is based on 18 semi-structured interviews with 33 refugees who returned after long-term residence in Denmark. We found that the returned refugees faced greater problems with corruption than was the case for those who had not left the country, as doctors considered them to be better endowed financially and therefore demanded larger bribes from them than they did from those who had remained in Bosnia. Moreover, during their stay abroad the returnees had lost the connections that could have helped them sidestep the corruption. Returned refugees are thus particularly vulnerable to the effects of corruption. PMID:27657096

  20. Systems implications of L-band fade data statistics for LEO mobile systems

    NASA Technical Reports Server (NTRS)

    Devieux, Carrie L.

    1993-01-01

    This paper examines and analyzes research data on the role of foliage attenuation in signal fading between a satellite transmitter and a terrestrial vehicle-mounted receiver. The frequency band of measurement, called L-Band, includes the region 1610.0 to 1626.5 MHz. Data from tests involving various combinations of foliage and vehicle movement conditions clearly show evidence of fast fading (in excess of 0.5 dB per millisecond) and fade depths as great or greater than 16 dB. As a result, the design of a communications link power control that provides the level of accuracy necessary for power sensitive systems could be significantly impacted. Specific examples of this include the communications links that employ Code Division Multiple Access (CDMA) as a modulation technique.

  1. Multiple Coaxial Catheter System for Reliable Access in Interventional Stroke Therapy

    SciTech Connect

    Kulcsar, Zsolt Yilmaz, Hasan; Bonvin, Christophe; Lovblad, Karl O.; Ruefenacht, Daniel A.

    2010-12-15

    In some patients with acute cerebral vessel occlusion, navigating mechanical thrombectomy systems is difficult due to tortuous anatomy of the aortic arch, carotid arteries, or vertebral arteries. Our purpose was to describe a multiple coaxial catheter system used for mechanical revascularization that helps navigation and manipulations in tortuous vessels. A triple or quadruple coaxial catheter system was built in 28 consecutive cases presenting with acute ischemic stroke. All cases were treated by mechanical thrombectomy with the Penumbra System. In cases of unsuccessful thrombo-aspiration, additional thrombolysis or angioplasty with stent placement was used for improving recanalization. The catheter system consisted of an outermost 8-Fr and an intermediate 6-Fr guiding catheter, containing the inner Penumbra reperfusion catheters. The largest, 4.1-Fr, reperfusion catheter was navigated over a Prowler Select Plus microcatheter. The catheter system provided access to reach the cerebral lesions and provided stability for the mechanically demanding manipulations of thromboaspiration and stent navigation in all cases. Apart from their mechanical role, the specific parts of the system could also provide access to different types of interventions, like carotid stenting through the 8-Fr guiding catheter and intracranial stenting and thrombolysis through the Prowler Select Plus microcatheter. In this series, there were no complications related to the catheter system. In conclusion, building up a triple or quadruple coaxial system proved to be safe and efficient in our experience for the mechanical thrombectomy treatment of acute ischemic stroke.

  2. Percutaneous inner-ear access via an image-guided industrial robot system.

    PubMed

    Baron, S; Eilers, H; Munske, B; Toennies, J L; Balachandran, R; Labadie, R F; Ortmaier, T; Webster, R J

    2010-01-01

    Image-guided robots have been widely used for bone shaping and percutaneous access to interventional sites. However, due to high-accuracy requirements and proximity to sensitive nerves and brain tissues, the adoption of robots in inner-ear surgery has been slower. In this paper the authors present their recent work towards developing two image-guided industrial robot systems for accessing challenging inner-ear targets. Features of the systems include optical tracking of the robot base and tool relative to the patient and Kalman filter-based data fusion of redundant sensory information (from encoders and optical tracking systems) for enhanced patient safety. The approach enables control of differential robot positions rather than absolute positions, permitting simplified calibration procedures and reducing the reliance of the system on robot calibration in order to ensure overall accuracy. Lastly, the authors present the results of two phantom validation experiments simulating the use of image-guided robots in inner-ear surgeries such as cochlear implantation and petrous apex access.

  3. Percutaneous inner-ear access via an image-guided industrial robot system

    PubMed Central

    Baron, S; Eilers, H; Munske, B; Toennies, JL; Balachandran, R; Labadie, RF; Ortmaier, T; Webster, RJ

    2014-01-01

    Image-guided robots have been widely used for bone shaping and percutaneous access to interventional sites. However, due to high-accuracy requirements and proximity to sensitive nerves and brain tissues, the adoption of robots in inner-ear surgery has been slower. In this paper the authors present their recent work towards developing two image-guided industrial robot systems for accessing challenging inner-ear targets. Features of the systems include optical tracking of the robot base and tool relative to the patient and Kalman filter-based data fusion of redundant sensory information (from encoders and optical tracking systems) for enhanced patient safety. The approach enables control of differential robot positions rather than absolute positions, permitting simplified calibration procedures and reducing the reliance of the system on robot calibration in order to ensure overall accuracy. Lastly, the authors present the results of two phantom validation experiments simulating the use of image-guided robots in inner-ear surgeries such as cochlear implantation and petrous apex access. PMID:20718268

  4. Access to the UW System for Wisconsin High School Graduates. Occasional Research Brief, Volume 00, No. 2.

    ERIC Educational Resources Information Center

    Wisconsin Univ. System, Madison.

    This paper examines trends in access rates to the University of Wisconsin (UW) system from the mid 1970s to the late 1990s with particular emphasis on how enrollment management planning for the mid to late 1990s affected the overall UW system access rate for resident undergraduates and how the application and admission patterns of these high…

  5. 28 CFR 16.83 - Exemption of the Executive Office for Immigration Review System-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Immigration Review System-limited access. 16.83 Section 16.83 Judicial Administration DEPARTMENT OF JUSTICE....83 Exemption of the Executive Office for Immigration Review System—limited access. (a) The following system of records is exempt from 5 U.S.C. 552a(d): (1) The Executive Office for Immigration...

  6. 28 CFR 16.83 - Exemption of the Executive Office for Immigration Review System-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Immigration Review System-limited access. 16.83 Section 16.83 Judicial Administration DEPARTMENT OF JUSTICE....83 Exemption of the Executive Office for Immigration Review System—limited access. (a) The following system of records is exempt from 5 U.S.C. 552a(d): (1) The Executive Office for Immigration...

  7. 28 CFR 16.83 - Exemption of the Executive Office for Immigration Review System-limited access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Immigration Review System-limited access. 16.83 Section 16.83 Judicial Administration DEPARTMENT OF JUSTICE....83 Exemption of the Executive Office for Immigration Review System—limited access. (a) The following system of records is exempt from 5 U.S.C. 552a(d): (1) The Executive Office for Immigration...

  8. 28 CFR 16.83 - Exemption of the Executive Office for Immigration Review System-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Immigration Review System-limited access. 16.83 Section 16.83 Judicial Administration DEPARTMENT OF JUSTICE....83 Exemption of the Executive Office for Immigration Review System—limited access. (a) The following system of records is exempt from 5 U.S.C. 552a(d): (1) The Executive Office for Immigration...

  9. 28 CFR 16.83 - Exemption of the Executive Office for Immigration Review System-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Immigration Review System-limited access. 16.83 Section 16.83 Judicial Administration DEPARTMENT OF JUSTICE....83 Exemption of the Executive Office for Immigration Review System—limited access. (a) The following system of records is exempt from 5 U.S.C. 552a(d): (1) The Executive Office for Immigration...

  10. 50 CFR 622.372 - Limited access system for king mackerel gillnet permits applicable in the southern Florida west...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Limited access system for king mackerel... Pelagic Resources (Gulf of Mexico and South Atlantic) § 622.372 Limited access system for king mackerel... renewals of king mackerel gillnet permits, no applications for king mackerel gillnet permits will...

  11. 50 CFR 622.372 - Limited access system for king mackerel gillnet permits applicable in the southern Florida west...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Limited access system for king mackerel... Pelagic Resources (Gulf of Mexico and South Atlantic) § 622.372 Limited access system for king mackerel... renewals of king mackerel gillnet permits, no applications for king mackerel gillnet permits will...

  12. Access to care provided by better safety net systems for the uninsured: measuring and conceptualizing adequacy.

    PubMed

    Hall, Mark A

    2011-08-01

    This descriptive study assesses the access to care provided by five model and diverse safety net programs that enroll uninsured adults in a coordinated system offering primary care, hospital care, prescription drugs, and most specialist services. Physician use by safety net program members was similar to insured groups. However, there was less use of hospitals in the two programs that relied on uncompensated charity care. Considering access measures commonly used in population-based surveys, the uninsured in these five communities fared no better than uninsured elsewhere. However, respondents may consider enrollment in a well-structured safety net program to be equivalent to insurance. If so, population surveys may be least accurate in identifying uninsured people in the very communities that have the best safety net programs. On balance the five safety net systems profiled here meet the needs of low-income uninsured residents at a level that is roughly similar to that for people with insurance.

  13. Climate Change and Global Food Security: Food Access, Utilization, and the US Food System

    NASA Astrophysics Data System (ADS)

    Brown, M. E.; Antle, J. M.; Backlund, P. W.; Carr, E. R.; Easterling, W. E.; Walsh, M.; Ammann, C. M.; Attavanich, W.; Barrett, C. B.; Bellemare, M. F.; Dancheck, V.; Funk, C.; Grace, K.; Ingram, J. S. I.; Jiang, H.; Maletta, H.; Mata, T.; Murray, A.; Ngugi, M.; Ojima, D. S.; O'Neill, B. C.; Tebaldi, C.

    2015-12-01

    This paper will summarize results from the USDA report entitled 'Climate change, Global Food Security and the U.S. Food system'. The report focuses on the impact of climate change on global food security, defined as "when all people at all times have physical, social, and economic access to sufficient, safe, and nutritious food to meet their dietary needs and food preferences for an active and healthy life". The assessment brought together authors and contributors from twenty federal, academic, nongovernmental, intergovernmental, and private organizations in four countries to identify climate change effects on food security through 2100, and analyze the U.S.'s likely connections with that world. This talk will describe how climate change will likely affect food access and food utilization, and summarize how the U.S. food system contributes to global food security, and will be affected by climate change.

  14. Access to Vocational Education. A Planning System for Local Secondary and Post-Secondary Program and Facility Accessibility. Step 5: Removing Barriers.

    ERIC Educational Resources Information Center

    Rice, Eric; And Others

    This guidebook focuses on the final step included in a five-step planning system for improving local secondary and postsecondary programs and facilities accessibility: removing barriers. The guidebook is comprised of self-instructional discussions of three techniques that can be used in planning for implementation of barrier-removal strategies:…

  15. Creating a front porch in systems of care: improving access to behavioral health services for diverse children and families.

    PubMed

    Callejas, Linda M; Hernandez, Mario; Nesman, Teresa; Mowery, Debra

    2010-02-01

    Despite recognition of the central role that service accessibility (and availability) should assume within a system of care, the definition proposed in the feature article of this special issue does not identify specific factors that systems of care must take into account in order to serve diverse children with serious emotional disturbance and their families in a culturally competent manner. This paper provides support for inclusion of the concepts of access and availability in the system of care definition and presents important factors that systems of care must take into account in order to increase access in a culturally competent manner, a core system of care value.

  16. Exploring the drivers of health and healthcare access in Zambian prisons: a health systems approach

    PubMed Central

    Topp, Stephanie M.; Moonga, Clement N.; Luo, Nkandu; Kaingu, Michael; Chileshe, Chisela; Magwende, George; Heymann, S. Jody; Henostroza, German

    2016-01-01

    Background Prison populations in sub-Saharan Africa (SSA) experience a high burden of disease and poor access to health care. Although it is generally understood that environmental conditions are dire and contribute to disease spread, evidence of how environmental conditions interact with facility-level social and institutional factors is lacking. This study aimed to unpack the nature of interactions and their influence on health and healthcare access in the Zambian prison setting. Methods We conducted in-depth interviews of a clustered random sample of 79 male prisoners across four prisons, as well as 32 prison officers, policy makers and health care workers. Largely inductive thematic analysis was guided by the concepts of dynamic interaction and emergent behaviour, drawn from the theory of complex adaptive systems. Results A majority of inmates, as well as facility-based officers reported anxiety linked to overcrowding, sanitation, infectious disease transmission, nutrition and coercion. Due in part to differential wealth of inmates and their support networks on entering prison, and in part to the accumulation of authority and material wealth within prison, we found enormous inequity in the standard of living among prisoners at each site. In the context of such inequities, failure of the Zambian prison system to provide basic necessities (including adequate and appropriate forms of nutrition, or access to quality health care) contributed to high rates of inmate-led and officer-led coercion with direct implications for health and access to healthcare. Conclusions This systems-oriented analysis provides a more comprehensive picture of the way resource shortages and human interactions within Zambian prisons interact and affect inmate and officer health. While not a panacea, our findings highlight some strategic entry-points for important upstream and downstream reforms including urgent improvement in the availability of human resources for health; strengthening of

  17. Web-Based Geographic Information System Tool for Accessing Hanford Site Environmental Data

    SciTech Connect

    Triplett, Mark B.; Seiple, Timothy E.; Watson, David J.; Charboneau, Briant L.; Morse, John G.

    2014-11-15

    Data volume, complexity, and access issues pose severe challenges for analysts, regulators and stakeholders attempting to efficiently use legacy data to support decision making at the U.S. Department of Energy’s (DOE) Hanford Site. DOE has partnered with the Pacific Northwest National Laboratory (PNNL) on the PHOENIX (PNNL-Hanford Online Environmental Information System) project, which seeks to address data access, transparency, and integration challenges at Hanford to provide effective decision support. PHOENIX is a family of spatially-enabled web applications providing quick access to decades of valuable scientific data and insight through intuitive query, visualization, and analysis tools. PHOENIX realizes broad, public accessibility by relying only on ubiquitous web-browsers, eliminating the need for specialized software. It accommodates a wide range of users with intuitive user interfaces that require little or no training to quickly obtain and visualize data. Currently, PHOENIX is actively hosting three applications focused on groundwater monitoring, groundwater clean-up performance reporting, and in-tank monitoring. PHOENIX-based applications are being used to streamline investigative and analytical processes at Hanford, saving time and money. But more importantly, by integrating previously isolated datasets and developing relevant visualization and analysis tools, PHOENIX applications are enabling DOE to discover new correlations hidden in legacy data, allowing them to more effectively address complex issues at Hanford.

  18. Frequency-selective design of wireless power transfer systems for controlled access applications

    NASA Astrophysics Data System (ADS)

    Maschino, Tyler Stephen

    Wireless power transfer (WPT) has become a common way to charge or power many types of devices, ranging from cell phones to electric toothbrushes. WPT became popular through the introduction of a transmission mode known as strongly coupled magnetic resonance (SCMR). This means of transmission is non-radiative and enables mid-range WPT. Shortly after the development of WPT via SCMR, a group of researchers introduced the concept of resonant repeaters, which allows power to hop from the source to the device. These repeaters are in resonance with the WPT system, which enables them to propagate the power wirelessly with minimal losses to the environment. Resonant repeaters have rekindled the dream of ubiquitous wireless power. Inherent risks come with the realization of such a dream. One of the most prominent risks, which we set out in this thesis to address, is that of accessibility to the WPT system. We propose the incorporation of a controlled access schema within a WPT system to prevent unwarranted use of wireless power. Our thesis discusses the history of electromagnetism, examines the inception of WPT via SCMR, evaluates recent developments in WPT, and further elaborates on the controlled access schema we wish to contribute to the field.

  19. Access Denied

    ERIC Educational Resources Information Center

    Villano, Matt

    2008-01-01

    Building access control (BAC)--a catchall phrase to describe the systems that control access to facilities across campus--has traditionally been handled with remarkably low-tech solutions: (1) manual locks; (2) electronic locks; and (3) ID cards with magnetic strips. Recent improvements have included smart cards and keyless solutions that make use…

  20. Orthogonal frequency-division multiplexing access (OFDMA) based wireless visible light communication (VLC) system

    NASA Astrophysics Data System (ADS)

    Sung, Jiun-Yu; Yeh, Chien-Hung; Chow, Chi-Wai; Lin, Wan-Feng; Liu, Yang

    2015-11-01

    An orthogonal frequency-division multiplexing access (OFDMA) based visible light communication (VLC) system is proposed in this paper. The architecture of the proposed system is divided into several VLC cells, which is defined in this paper. The deployment and upgrade of the system involve only simple combination of the VLC cells. Hence it is economically advantageous. To guarantee smooth communication, nearly equal data rate is provided at every location within the system with no concern on the system scale. The user location monitor strategy is also discussed to solve the region division issues. The characteristics of the proposed system are analyzed in detail in this paper. A one-dimensional experiment was demonstrated with 13.6 Mb/s data rate.

  1. Global system data bus using the Digital Autonomous Terminal Access Communication protocol

    NASA Technical Reports Server (NTRS)

    Holmes, David C. E.

    1986-01-01

    Modern digital avionic systems with distributed processing require networking to connect the many elements. Digital Autonomous Terminal Access Communication (DATAC) is one of many such networks. DATAC has been implemented on the Transport Systems Research Vehicle (TSRV), a Boeing 737 aircraft operated by the National Aeronautics and Space Administration's Advanced Transport Operating Systems Program Office (ATOPS). This paper presents the TSRV implementation of the DATAC bus, a description of the DATAC system, a synchronization mechanism, details of data flow throughout the system, and a discussion of the modes available with DATAC. Numerous flight tests have been conducted using DATAC as the only means of communication between systems with outstanding results. DATAC is now an integral part of the TSRV and is expected to satisfy near term as well as future requirements for growth and flexibility.

  2. Vibroacoustic payload environment prediction system (VAPEPS): Data base management center remote access guide

    NASA Technical Reports Server (NTRS)

    Thomas, V. C.

    1986-01-01

    A Vibroacoustic Data Base Management Center has been established at the Jet Propulsion Laboratory (JPL). The center utilizes the Vibroacoustic Payload Environment Prediction System (VAPEPS) software package to manage a data base of shuttle and expendable launch vehicle flight and ground test data. Remote terminal access over telephone lines to a dedicated VAPEPS computer system has been established to provide the payload community a convenient means of querying the global VAPEPS data base. This guide describes the functions of the JPL Data Base Management Center and contains instructions for utilizing the resources of the center.

  3. An Automated Mouse Tail Vascular Access System by Vision and Pressure Feedback

    PubMed Central

    Chang, Yen-Chi; Berry-Pusey, Brittany; Yasin, Rashid; Vu, Nam; Maraglia, Brandon; Chatziioannou, Arion X.; Tsao, Tsu-Chin

    2015-01-01

    This paper develops an automated vascular access system (A-VAS) with novel vision-based vein and needle detection methods and real-time pressure feedback for murine drug delivery. Mouse tail vein injection is a routine but critical step for preclinical imaging applications. Due to the small vein diameter and external disturbances such as tail hair, pigmentation, and scales, identifying vein location is difficult and manual injections usually result in poor repeatability. To improve the injection accuracy, consistency, safety, and processing time, A-VAS was developed to overcome difficulties in vein detection noise rejection, robustness in needle tracking, and visual servoing integration with the mechatronics system. PMID:26478693

  4. Multiple fiber Bragg grating sensor system using code-division multiple access.

    PubMed

    Lee, Hojoon

    2002-09-01

    We propose and demonstrate experimentally a multiple fiber Bragg grating sensor system that uses a LED as a light source and adapts the code-division multiple access method to separate individual sensor signals. We measured static and dynamic strains and cross-talk levels among sensor signals. With our proposed scheme, a low-cost sensor system can be designed with a fast response speed. Cross-talk levels between sensor signals are found to be below the -30-dB level.

  5. Vibroacoustic Payload Environment Prediction System (VAPEPS): VAPEPS management center remote access guide

    NASA Technical Reports Server (NTRS)

    Fernandez, J. P.; Mills, D.

    1991-01-01

    A Vibroacoustic Payload Environment Prediction System (VAPEPS) Management Center was established at the JPL. The center utilizes the VAPEPS software package to manage a data base of Space Shuttle and expendable launch vehicle payload flight and ground test data. Remote terminal access over telephone lines to the computer system, where the program resides, was established to provide the payload community a convenient means of querying the global VAPEPS data base. This guide describes the functions of the VAPEPS Management Center and contains instructions for utilizing the resources of the center.

  6. The equipment access software for a distributed UNIX-based accelerator control system

    NASA Astrophysics Data System (ADS)

    Trofimov, Nikolai; Zelepoukine, Serguei; Zharkov, Eugeny; Charrue, Pierre; Gareyte, Claire; Poirier, Hervé

    1994-12-01

    This paper presents a generic equipment access software package for a distributed control system using computers with UNIX or UNIX-like operating systems. The package consists of three main components, an application Equipment Access Library, Message Handler and Equipment Data Base. An application task, which may run in any computer in the network, sends requests to access equipment through Equipment Library calls. The basic request is in the form Equipment-Action-Data and is routed via a remote procedure call to the computer to which the given equipment is connected. In this computer the request is received by the Message Handler. According to the type of the equipment connection, the Message Handler either passes the request to the specific process software in the same computer or forwards it to a lower level network of equipment controllers using MIL1553B, GPIB, RS232 or BITBUS communication. The answer is then returned to the calling application. Descriptive information required for request routing and processing is stored in the real-time Equipment Data Base. The package has been written to be portable and is currently available on DEC Ultrix, LynxOS, HPUX, XENIX, OS-9 and Apollo domain.

  7. [From library to clinical decision support systems: access of general practitioner to quality information].

    PubMed

    Fauquert, B

    2012-09-01

    Since 2003, the following tools have been implemented in Belgium for improving the access of general practioners to the EBM literature: the Digital Library for Health and the evidence-linker of the CEBAM, the portal EBMPracticeNet.be and the multidimensional electronic clinical decision support EBMeDS. The aim of this article is to show the progress achieved in the information dissemination toward the belgian general practioners, particularly the access from the electronic health record. From the literature published these last years, the opportunities cited by the users are for using EBM and the strong willingness for using these literature access in the future; the limits are the medical data coding, the irrelevance of the search results, the alerts fatigue induced by EBMeDS. The achievements done and planned for the new EBMPracticeNet guidelines portal and the EBMeDS system are explained in the aim of informing belgian healthcare professionals. These projects are claiming for lauching a participatory process in the production and dissemination of EBM information. The discussion is focused on the belgian healthcare system advantages, the solutions for a reasonable implementation of these projects and for increasing the place of an evidence-based information in the healthcare decision process. Finally the input of these projects to the continuing medical education and to the healthcare quality are discussed, in a context of multifactorial interaction healthcare design (complexity design).

  8. Using Speech Recognition to Enhance the Tongue Drive System Functionality in Computer Access

    PubMed Central

    Huo, Xueliang; Ghovanloo, Maysam

    2013-01-01

    Tongue Drive System (TDS) is a wireless tongue operated assistive technology (AT), which can enable people with severe physical disabilities to access computers and drive powered wheelchairs using their volitional tongue movements. TDS offers six discrete commands, simultaneously available to the users, for pointing and typing as a substitute for mouse and keyboard in computer access, respectively. To enhance the TDS performance in typing, we have added a microphone, an audio codec, and a wireless audio link to its readily available 3-axial magnetic sensor array, and combined it with a commercially available speech recognition software, the Dragon Naturally Speaking, which is regarded as one of the most efficient ways for text entry. Our preliminary evaluations indicate that the combined TDS and speech recognition technologies can provide end users with significantly higher performance than using each technology alone, particularly in completing tasks that require both pointing and text entry, such as web surfing. PMID:22255801

  9. Improving Access to Essential Medicines: How Health Concerns can be Prioritised in the Global Governance System

    PubMed Central

    Sridhar, Devi

    2008-01-01

    This paper discusses the politics of access to essential medicines and identifies ‘space’ in the current system where health concerns can be strengthened relative to trade. This issue is addressed from a global governance perspective focusing on the main actors who can have the greatest impact. These include developing country coalitions and citizens in developed countries though participation in civil society organisations. These actors have combined forces to tackle this issue successfully, resulting in the 2001 Doha Declaration on Public Health. The collaboration has been so powerful due to the assistance of the media as well as the decision to compromise with pharmaceutical companies and their host countries. To improve access to essential medicines, six C's are needed: coalitions, civil society, citizenship, compromise, communication and collaboration. PMID:19461853

  10. Elevated waterproof access floor system and method of making the same

    NASA Technical Reports Server (NTRS)

    Cohen, Marc M. (Inventor)

    1987-01-01

    An elevated waterproof access floor system having subfloor channels or compartments for power lines, gas lines or the like is adapted such that it can be opened and subsequently resealed without destroying the waterproofing and without destroying its aesthetic appearance. A multiplicity of tiles are supported on a support grid, and a flooring sheet is supported on the tiles. Attachment means are provided to prevent lateral but not vertical movement of the flooring sheet with respect to the tiles so that the flooring sheet can be lifted off the tiles, but when the flooring sheet is supported on the tiles, no lateral slipping will occur. The flooring sheet is made of a heat resealable material, so that it can be cut away in sections, and the tiles therebelow lifted off, to provide access to subfloor compartments.

  11. Health care access and use among handicapped students in five public school systems.

    PubMed

    Singer, J D; Butler, J A; Palfrey, J S

    1986-01-01

    The authors studied the health care access and utilization patterns for a stratified random sample of 1,726 special education students in five large metropolitan school systems. Overall, 7% of the special education students had no regular source of care, 26% had no regular physician, and 38% had not visited a physician in the previous year; 13% had no health insurance. Each of these measures was worse for nonwhite and poorer children as well as for those whose mothers who had less formal education. Insurance coverage was associated with physician visits, with 45% of the uninsured children visiting a physician compared with 63% of those with public insurance and 66% of those with private insurance. Odds ratios for all health care access and use measures showed striking geographic variations. Thus, even for children identified as handicapped by their communities, barriers to health care are evident and are significantly greater for groups traditionally at risk.

  12. Open-Access, Low-Magnetic-Field MRI System for Lung Research

    NASA Technical Reports Server (NTRS)

    Mair, Ross W.; Rosen, Matthew S.; Tsai, Leo L.; Walsworth, Ronald L.; Hrovat, Mirko I.; Patz, Samuel; Ruset, Iullian C.; Hersman, F. William

    2009-01-01

    An open-access magnetic resonance imaging (MRI) system is being developed for use in research on orientational/gravitational effects on lung physiology and function. The open-access geometry enables study of human subjects in diverse orientations. This system operates at a magnetic flux density, considerably smaller than the flux densities of typical other MRI systems, that can be generated by resistive electromagnet coils (instead of the more-expensive superconducting coils of the other systems). The human subject inhales air containing He-3 or Xe-129 atoms, the nuclear spins of which have been polarized by use of a laser beam to obtain a magnetic resonance that enables high-resolution gas space imaging at the low applied magnetic field. The system includes a bi-planar, constant-current, four-coil electromagnet assembly and associated electronic circuitry to apply a static magnetic field of 6.5 mT throughout the lung volume; planar coils and associated circuitry to apply a pulsed magnetic-field-gradient for each spatial dimension; a single, detachable radio-frequency coil and associated circuitry for inducing and detecting MRI signals; a table for supporting a horizontal subject; and electromagnetic shielding surrounding the electromagnet coils.

  13. National Geothermal Data System: Open Access to Geoscience Data, Maps, and Documents

    NASA Astrophysics Data System (ADS)

    Caudill, C. M.; Richard, S. M.; Musil, L.; Sonnenschein, A.; Good, J.

    2014-12-01

    The U.S. National Geothermal Data System (NGDS) provides free open access to millions of geoscience data records, publications, maps, and reports via distributed web services to propel geothermal research, development, and production. NGDS is built on the US Geoscience Information Network (USGIN) data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG), and is compliant with international standards and protocols. NGDS currently serves geoscience information from 60+ data providers in all 50 states. Free and open source software is used in this federated system where data owners maintain control of their data. This interactive online system makes geoscience data easily discoverable, accessible, and interoperable at no cost to users. The dynamic project site http://geothermaldata.org serves as the information source and gateway to the system, allowing data and applications discovery and availability of the system's data feed. It also provides access to NGDS specifications and the free and open source code base (on GitHub), a map-centric and library style search interface, other software applications utilizing NGDS services, NGDS tutorials (via YouTube and USGIN site), and user-created tools and scripts. The user-friendly map-centric web-based application has been created to support finding, visualizing, mapping, and acquisition of data based on topic, location, time, provider, or key words. Geographic datasets visualized through the map interface also allow users to inspect the details of individual GIS data points (e.g. wells, geologic units, etc.). In addition, the interface provides the information necessary for users to access the GIS data from third party software applications such as GoogleEarth, UDig, and ArcGIS. A redistributable, free and open source software package called GINstack (USGIN software stack) was also created to give data providers a simple way to release data using

  14. Germplasm Conservation and Access to Genetic Resources: National Plant Germplasm System and the National Clonal Germplasm Repository

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US National Plant Germplasm System (NPGS) conserves more than 550,000 accessions of genetic resources of crop wild relatives and cultivated, economically important crops. These accessions represent more than 20,000 plant species and are stored at about 25 locations throughout the United States. ...

  15. Access to Academic Curriculum in Australian Secondary Schools: A Case Study of a Highly Marketised Education System

    ERIC Educational Resources Information Center

    Perry, Laura B.; Southwell, Leonie

    2014-01-01

    This study examines how access to academic curriculum differs between secondary schools in Australia, a country whose education system is marked by high levels of choice, privatisation and competition. Equitable access to academic curriculum is important for both individual students and their families as well as the larger society. Previous…

  16. Architecture and implementation for a system enabling smartphones to access smart card based healthcare records.

    PubMed

    Karampelas, Vasilios; Pallikarakis, Nicholas; Mantas, John

    2013-01-01

    The healthcare researchers', academics' and practitioners' interest concerning the development of Healthcare Information Systems has been on a steady rise for the last decades. Fueling this steady rise has been the healthcare professional need of quality information, in every healthcare provision incident, whenever and wherever this incident may take place. In order to address this need a truly mobile health care system is required, one that will be able to provide a healthcare provider with accurate patient-related information regardless of the time and place that healthcare is provided. In order to fulfill this role the present study proposes the architecture for a Healthcare Smartcard system, which provides authenticated healthcare professionals with remote mobile access to a Patient's Healthcare Record, through their Smartphone. Furthermore the research proceeds to develop a working prototype system.

  17. Architecture and implementation for a system enabling smartphones to access smart card based healthcare records.

    PubMed

    Karampelas, Vasilios; Pallikarakis, Nicholas; Mantas, John

    2013-01-01

    The healthcare researchers', academics' and practitioners' interest concerning the development of Healthcare Information Systems has been on a steady rise for the last decades. Fueling this steady rise has been the healthcare professional need of quality information, in every healthcare provision incident, whenever and wherever this incident may take place. In order to address this need a truly mobile health care system is required, one that will be able to provide a healthcare provider with accurate patient-related information regardless of the time and place that healthcare is provided. In order to fulfill this role the present study proposes the architecture for a Healthcare Smartcard system, which provides authenticated healthcare professionals with remote mobile access to a Patient's Healthcare Record, through their Smartphone. Furthermore the research proceeds to develop a working prototype system. PMID:23823404

  18. Remote access to an interferometric fringes stabilization active system via RENATA

    NASA Astrophysics Data System (ADS)

    Espitia-Gómez, Javier; Ángel-Toro, Luciano

    2013-11-01

    The Advanced Technology National Network (RENATA, for its acronym in Spanish) is a Colombian, collaborative work tool, linked to other networks worldwide, in which take participation researchers, teachers and students, by sharing laboratory resources located in different universities, institutes and research centers throughout the country. In the Universidad EAFIT (Medellín, Colombia) it has been designed an interferometric fringes stabilization active system, which can be accessed remotely via the RENATA network. A Mach-Zehnder interferometer was implemented, with independent piezoelectric actuators in each arm, with which the lengths of optical path of light that goes over in each of them can be modified. Using these actuators, one can simultaneously perturb the system and compensate the phase differences caused by that perturbation. This allows us to experiment with different disturbs, and analyze the system response to each one of them. This can be made from any location worldwide, and especially from those regions in which optical and optoelectronic components required for the implementation of the interferometer or for the stabilization system are not available. The device can also be used as a platform in order to conduct diverse experiments, involving optical and controlling aspects, constituting with this in a pedagogic tool. For the future, it can be predicted that remote access to available applications would be possible, as well as modifications of the implemented code in labVIEW™, so that researchers and teachers can adapt and improve their functionalities or develop new applications, based on the collaborative work.

  19. Motion Planning for a Three-Stage Multilumen Transoral Lung Access System

    PubMed Central

    Kuntz, Alan; Torres, Luis G.; Feins, Richard H.; Webster, Robert J.; Alterovitz, Ron

    2015-01-01

    Lung cancer is the leading cause of cancer-related death, and early-stage diagnosis is critical to survival. Biopsy is typically required for a definitive diagnosis, but current low-risk clinical options for lung biopsy cannot access all biopsy sites. We introduce a motion planner for a multilumen transoral lung access system, a new system that has the potential to perform safe biopsies anywhere in the lung, which could enable more effective early-stage diagnosis of lung cancer. The system consists of three stages in which a bronchoscope is deployed transorally to the lung, a concentric tube robot pierces through the bronchial tubes into the lung parenchyma, and a steerable needle deploys through a properly oriented concentric tube and steers through the lung parenchyma to the target site while avoiding anatomical obstacles such as significant blood vessels. A sampling-based motion planner computes actions for each stage of the system and considers the coupling of the stages in an efficient manner. We demonstrate the motion planner's fast performance and ability to compute plans with high clearance from obstacles in simulated anatomical scenarios. PMID:26942041

  20. A replacement strategy for a distributed caching system based on the spatiotemporal access pattern of geospatial data

    NASA Astrophysics Data System (ADS)

    Li, R.; Wang, X.; Shi, X.

    2014-04-01

    Cache replacement strategy is the core for a distributed high-speed caching system, and effects the cache hit rate and utilization of a limited cache space directly. Many reports show that there are temporal and spatial local changes in access patterns of geospatial data, and there are popular hot spots which change over time. Therefore, the key issue for cache replacement strategy for geospatial data is to get a combination method which considers both temporal local changes and spatial local changes in access patterns, and balance the relationship between the changes. And the cache replacement strategy should fit the distribution and changes of hotspot. This paper proposes a cache replacement strategy based on access pattern which have access spatiotemporal localities. Firstly, the strategy builds a method to express the access frequency and the time interval for geospatial data access based on a least-recently-used replacement (LRU) algorithm and its data structure; secondly, considering both the spatial correlation between geospatial data access and the caching location for geospatial data, it builds access sequences based on a LRU stack, which reflect the spatiotemporal locality changes in access pattern. Finally, for achieving the aim of balancing the temporal locality and spatial locality changes in access patterns, the strategy chooses the replacement objects based on the length of access sequences and the cost of caching resource consumption. Experimental results reveal that the proposed cache replacement strategy is able to improve the cache hit rate while achieving a good response performance and higher system throughput. Therefore, it can be applied to handle the intensity of networked GISs data access requests in a cloud-based environment.

  1. Accessibility patterns and community integration among previously homeless adults: a Geographic Information Systems (GIS) approach.

    PubMed

    Chan, Dara V; Gopal, Sucharita; Helfrich, Christine A

    2014-11-01

    Although a desired rehabilitation goal, research continues to document that community integration significantly lags behind housing stability success rates for people of a variety of ages who used to be homeless. While accessibility to resources is an environmental factor that may promote or impede integration activity, there has been little empirical investigation into the impact of proximity of community features on resource use and integration. Using a Geographic Information Systems (GIS) approach, the current study examines how accessibility or proximity to community features in Boston, United States related to the types of locations used and the size of an individual's "activity space," or spatial presence in the community. Significant findings include an inverse relationship between activity space size and proximity to the number and type of community features in one's immediate area. Specifically, larger activity spaces were associated with neighborhoods with less community features, and smaller activity spaces corresponded with greater availability of resources within one's immediate area. Activity space size also varied, however, based on proximity to different types of resources, namely transportation and health care. Greater community function, or the ability to navigate and use community resources, was associated with better accessibility and feeling part of the community. Finally, proximity to a greater number of individual identified preferred community features was associated with better social integration. The current study suggests the ongoing challenges of successful integration may vary not just based on accessibility to, but relative importance of, specific community features and affinity with one's surroundings. Community integration researchers and housing providers may need to attend to the meaning attached to resources, not just presence or use in the community.

  2. National Geothermal Data System (USA): an Exemplar of Open Access to Data

    NASA Astrophysics Data System (ADS)

    Allison, M. Lee; Richard, Stephen; Blackman, Harold; Anderson, Arlene; Patten, Kim

    2014-05-01

    The National Geothermal Data System's (NGDS - www.geothermaldata.org) formal launch in April, 2014 will provide open access to millions of data records, sharing -relevant geoscience and longer term to land use data to propel geothermal development and production. NGDS serves information from all of the U.S. Department of Energy's sponsored development and research projects and geologic data from all 50 states, using free and open source software. This interactive online system is opening new exploration opportunities and potentially shortening project development by making data easily discoverable, accessible, and interoperable. We continue to populate our prototype functional data system with multiple data nodes and nationwide data online and available to the public. Data from state geological surveys and partners includes more than 6 million records online, including 1.72 million well headers (oil and gas, water, geothermal), 670,000 well logs, and 497,000 borehole temperatures and is growing rapidly. There are over 312 interoperable Web services and another 106 WMS (Web Map Services) registered in the system as of January, 2014. Companion projects run by Southern Methodist University and U.S. Geological Survey (USGS) are adding millions of additional data records. The DOE Geothermal Data Repository, currently hosted on OpenEI, is a system node and clearinghouse for data from hundreds of U.S. DOE-funded geothermal projects. NGDS is built on the US Geoscience Information Network (USGIN) data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG). NGDS complies with the White House Executive Order of May 2013, requiring all federal agencies to make their data holdings publicly accessible online in open source, interoperable formats with common core and extensible metadata. The National Geothermal Data System is being designed, built, deployed, and populated primarily with support from the US

  3. Measuring access to primary medical care: some examples of the use of geographical information systems.

    PubMed

    Parker, E B; Campbell, J L

    1998-06-01

    This paper explores the potential for geographical information system technology in defining some variables influencing the use of primary care medical services. Eighteen general practices in Scotland contributed to a study examining the accessibility of their services and their patients' use of the local Accident and Emergency Department. Geo-referencing of information was carried out through analysis of postcode data relating to practices and patients. This information was analyzed using ARC/INFO GIS software in conjunction with the ORACLE relational database and 1991 census information. The results demonstrate that GIS technology has an important role in defining and analyzing the use of health services by the population. PMID:10671022

  4. Sub-THz photonic frequency conversion using optoelectronic transistors for future fully coherent access network systems

    NASA Astrophysics Data System (ADS)

    Otsuji, Taiichi; Sugawara, Kenta; Tamamushi, Gen; Dobroiu, Adrian; Suemitsu, Tetsuya; Ryzhii, Victor; Iwatsuki, Katsumi; Kuwano, Shigeru; Kani, Jun-ichi; Terada, Jun

    2016-02-01

    This paper reviews advances in sub-THz photonic frequency conversion using optoelectronic transistors for future fully coherent access network systems. Graphene-channel field effect transistors (G-FETs) and InP-based high electron mobility transistors (inP-HEMT) are experimentally examined as photonic frequency converters. Optoelectronic properties and three-terminal functionalities of the G-FETs and InP-HEMTs are exploited to perform single-chip photonic double-mixing operation over the 120 GHz wireless communication band. A single transistor can photomix the optical subcarriers to generate LO and mix down the RF data on the sub-THz carrier to the IF band.

  5. Ultrasonic Multiple-Access Ranging System Using Spread Spectrum and MEMS Technology for Indoor Localization

    PubMed Central

    Segers, Laurent; Tiete, Jelmer; Braeken, An; Touhafi, Abdellah

    2014-01-01

    Indoor localization of persons and objects poses a great engineering challenge. Previously developed localization systems demonstrate the use of wideband techniques in ultrasound ranging systems. Direct sequence and frequency hopping spread spectrum ultrasound signals have been proven to achieve a high level of accuracy. A novel ranging method using the frequency hopping spread spectrum with finite impulse response filtering will be investigated and compared against the direct sequence spread spectrum. In the first setup, distances are estimated in a single-access environment, while in the second setup, two senders and one receiver are used. During the experiments, the micro-electromechanical systems are used as ultrasonic sensors, while the senders were implemented using field programmable gate arrays. Results show that in a single-access environment, the direct sequence spread spectrum method offers slightly better accuracy and precision performance compared to the frequency hopping spread spectrum. When two senders are used, measurements point out that the frequency hopping spread spectrum is more robust to near-far effects than the direct sequence spread spectrum. PMID:24553084

  6. Ready access and utilization of data: Essential ingredients for global observation systems

    NASA Astrophysics Data System (ADS)

    Barton, C.; Baker, D. N.; Peterson, W. K.; Cobabe-Ammann, E.

    2007-12-01

    The anniversary years of 2007-2008 are widely known as the "IGY+50" period. There are several "International Years" that commemorate the IGY and build upon the IGY legacies. Two of the finest of these legacies are the foundation of a global information commons for Earth and space science, and the establishment of the system of World Data Centers. The first legacy finds expression today in the endeavor by the multi-national Group on Earth Observation (GEO) to build an open access Global Earth Observing System of Systems (GEOSS), and efforts such as the "Global Information Commons for Science Initiative" of ICSU's Committee on Data for Science and Technology (CODATA). Ready access to data and data preservation continues to be an essential ingredient for efficient science. There is also the realization that data and information from discipline specific data stores are very useful to investigators who do not work in the narrow discipline areas served by these particular data stores. Evolving data centers are then challenged to provide data and information to non-traditional users, creating new, flexible interfaces to meet their expanding audiences. In the present day, views differ about the future role of the World Data Centers established during IGY and who pays for them. This talk addresses the importance of good data management practices in global observation programs. From the viewpoint of the Electronic Geophysical Year (eGY), the presentation provides the international context for developing interoperability, data sharing capability, and the future of the WDCs.

  7. [Accession to the PIC/S and pharmaceutical quality system in Japan].

    PubMed

    Katori, Noriko

    2014-01-01

    In March, 2012, Japan made the application for membership of the Pharmaceutical Inspection convention and Pharmaceutical Inspection Co-operation scheme (PIC/S) which is an international body of a GMP inspection. The globalization of pharmaceutical manufacturing and sales has been a driving force behind the decision to become a PIC/S member. For the application for membership, Japan's GMP inspectorate needs to fulfill PIC/S requirements, for example, the inspection organization has to have a quality system as a global standard. One of the other requirements is that the GMP inspectorate can access Official Medicines Control Laboratories (OMCL) having high analytical skills and also have a quality system based on ISO 17025. I would like to describe the process to make up a quality system in the National Institute of Health Sciences and also the circumstances around the PIC/S application in Japan.

  8. [Accession to the PIC/S and pharmaceutical quality system in Japan].

    PubMed

    Katori, Noriko

    2014-01-01

    In March, 2012, Japan made the application for membership of the Pharmaceutical Inspection convention and Pharmaceutical Inspection Co-operation scheme (PIC/S) which is an international body of a GMP inspection. The globalization of pharmaceutical manufacturing and sales has been a driving force behind the decision to become a PIC/S member. For the application for membership, Japan's GMP inspectorate needs to fulfill PIC/S requirements, for example, the inspection organization has to have a quality system as a global standard. One of the other requirements is that the GMP inspectorate can access Official Medicines Control Laboratories (OMCL) having high analytical skills and also have a quality system based on ISO 17025. I would like to describe the process to make up a quality system in the National Institute of Health Sciences and also the circumstances around the PIC/S application in Japan. PMID:25707200

  9. NATIONAL GEOTHERMAL DATA SYSTEM: AN EXEMPLAR OF OPEN ACCESS TO DATA

    SciTech Connect

    Blackman, Harold; Blackman, Harold M.; Blackman, Harold M.; Blackman, Harold; Blackman, Harold; Blackman, Harold

    2013-10-01

    The formal launch of National Geothermal Data System (NGDS – www.geothermaldata.org) in 2014 will provide open access to technical geothermal-relevant data from all of the Department of Energy- sponsored geothermal development and research projects and geologic data from all 50 states. By making data easily discoverable and accessible this system will open new exploration opportunities and shorten project development. The prototype data system currently includes multiple data nodes, and nationwide data online and available to the public, indexed through a single catalog under construction at http://search.geothermaldata.org. Data from state geological surveys and partners includes more than 5 million records online, including 1.48 million well headers (oil and gas, water, geothermal), 732,000 well logs, and 314,000 borehole temperatures and is growing rapidly. There are over 250 Web services and another 138 WMS (Web Map Services) registered in the system as of August, 2013. Additional data record is being added by companion projects run by Boise State University, Southern Methodist University, and the USGS. The National Renewable Energy Laboratory is managing the Geothermal Data Repository, an NGDS node that will be a clearinghouse for data from hundreds of DOE-funded geothermal projects. NGDS is built on the US Geoscience Information Network (USGIN) data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG). NGDS is fully compliant with the White House Executive Order of May 2013, requiring all federal agencies to make their data holdings publicly accessible online in open source, interoperable formats with common core and extensible metadata. The National Geothermal Data System is being designed, built, deployed, and populated primarily with grants from the US Department of Energy, Geothermal Technologies Office. To keep this operational system sustainable after the original implementation will

  10. National Geothermal Data System: an Exemplar of Open Access to Data

    NASA Astrophysics Data System (ADS)

    Allison, M. L.; Richard, S. M.; Blackman, H.; Anderson, A.

    2013-12-01

    The National Geothermal Data System's (NGDS - www.geothermaldata.org) formal launch in 2014 will provide open access to millions of datasets, sharing technical geothermal-relevant data across the geosciences to propel geothermal development and production. With information from all of the Department of Energy's sponsored development and research projects and geologic data from all 50 states, this free, interactive tool is opening new exploration opportunities and shortening project development by making data easily discoverable and accessible. We continue to populate our prototype functional data system with multiple data nodes and nationwide data online and available to the public. Data from state geological surveys and partners includes more than 5 million records online, including 1.48 million well headers (oil and gas, water, geothermal), 732,000 well logs, and 314,000 borehole temperatures and is growing rapidly. There are over 250 Web services and another 138 WMS (Web Map Services) registered in the system as of August, 2013. Companion projects run by Boise State University, Southern Methodist University, and USGS are adding millions of additional data records. The National Renewable Energy Laboratory is managing the Geothermal Data Repository which will serve as a system node and clearinghouse for data from hundreds of DOE-funded geothermal projects. NGDS is built on the US Geoscience Information Network data integration framework, which is a joint undertaking of the USGS and the Association of American State Geologists (AASG). NGDS is fully compliant with the White House Executive Order of May 2013, requiring all federal agencies to make their data holdings publicly accessible online in open source, interoperable formats with common core and extensible metadata. The National Geothermal Data System is being designed, built, deployed, and populated primarily with grants from the US Department of Energy, Geothermal Technologies Office. To keep this operational

  11. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Attorney General System-limited access. 16.71 Section 16.71 Judicial Administration DEPARTMENT OF JUSTICE... Records System (JUSTICE/DAG-006). (2) Presidential Appointee Records System (JUSTICE/DAG-007). (3) Special Candidates for Presidential Appointments Records System (JUSTICE/DAG-008). (4) Miscellaneous...

  12. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Attorney General System-limited access. 16.71 Section 16.71 Judicial Administration DEPARTMENT OF JUSTICE... Records System (JUSTICE/DAG-006). (2) Presidential Appointee Records System (JUSTICE/DAG-007). (3) Special Candidates for Presidential Appointments Records System (JUSTICE/DAG-008). (4) Miscellaneous...

  13. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Attorney General System-limited access. 16.71 Section 16.71 Judicial Administration DEPARTMENT OF JUSTICE... Records System (JUSTICE/DAG-006). (2) Presidential Appointee Records System (JUSTICE/DAG-007). (3) Special Candidates for Presidential Appointments Records System (JUSTICE/DAG-008). (4) Miscellaneous...

  14. 28 CFR 16.71 - Exemption of the Office of the Deputy Attorney General System-limited access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Attorney General System-limited access. 16.71 Section 16.71 Judicial Administration DEPARTMENT OF JUSTICE... Records System (JUSTICE/DAG-006). (2) Presidential Appointee Records System (JUSTICE/DAG-007). (3) Special Candidates for Presidential Appointments Records System (JUSTICE/DAG-008). (4) Miscellaneous...

  15. Smartphone-based system to improve transportation access for the cognitively impaired.

    PubMed

    Anderson, Shane M; Riehle, Timothy H; Lichter, Patrick A; Brown, Allen W; Panescu, Dorin

    2015-08-01

    This project developed and evaluated a smartphone-based system to improve mobility and transportation access for the cognitively impaired. The proposed system is intended to allow the cognitively impaired to use public transportation systems, community transportation and dedicated transportation services for the disabled with greater ease and safety. Individuals with cognitive disabilities are often unable to operate an automobile, or may require a prolonged recovery period before resuming driving. Public transportation systems represent a significant means to allow these individuals to maintain independence. Yet public transportation systems can pose significant challenges to individuals with cognitive impairment. The goal of this project is to develop a system to reduce these barriers via a technological solution consisting of components developed both for the cognitively impaired user and their caregiver or family member. The first component consists of a cognitive prosthetic device featuring traditional memory cueing and reminders as well as custom location-based transportation specific functions. This cognitive mobility assistant will leverage the computing power and GPS location determination capabilities of inexpensive, powerful smart phones. The second component consists of a management application which offers caregivers the ability to configure and program the reminder and transit functions remotely via the Internet. Following completion of the prototype system a pilot human test was performed with cognitively disabled individuals and family members or caregivers to assess the usability and acceptability of both system components. PMID:26738091

  16. Smartphone-based system to improve transportation access for the cognitively impaired.

    PubMed

    Anderson, Shane M; Riehle, Timothy H; Lichter, Patrick A; Brown, Allen W; Panescu, Dorin

    2015-01-01

    This project developed and evaluated a smartphone-based system to improve mobility and transportation access for the cognitively impaired. The proposed system is intended to allow the cognitively impaired to use public transportation systems, community transportation and dedicated transportation services for the disabled with greater ease and safety. Individuals with cognitive disabilities are often unable to operate an automobile, or may require a prolonged recovery period before resuming driving. Public transportation systems represent a significant means to allow these individuals to maintain independence. Yet public transportation systems can pose significant challenges to individuals with cognitive impairment. The goal of this project is to develop a system to reduce these barriers via a technological solution consisting of components developed both for the cognitively impaired user and their caregiver or family member. The first component consists of a cognitive prosthetic device featuring traditional memory cueing and reminders as well as custom location-based transportation specific functions. This cognitive mobility assistant will leverage the computing power and GPS location determination capabilities of inexpensive, powerful smart phones. The second component consists of a management application which offers caregivers the ability to configure and program the reminder and transit functions remotely via the Internet. Following completion of the prototype system a pilot human test was performed with cognitively disabled individuals and family members or caregivers to assess the usability and acceptability of both system components.

  17. Interface of the transport systems research vehicle monochrome display system to the digital autonomous terminal access communication data bus

    NASA Technical Reports Server (NTRS)

    Easley, W. C.; Tanguy, J. S.

    1986-01-01

    An upgrade of the transport systems research vehicle (TSRV) experimental flight system retained the original monochrome display system. The original host computer was replaced with a Norden 11/70, a new digital autonomous terminal access communication (DATAC) data bus was installed for data transfer between display system and host, while a new data interface method was required. The new display data interface uses four split phase bipolar (SPBP) serial busses. The DATAC bus uses a shared interface ram (SIR) for intermediate storage of its data transfer. A display interface unit (DIU) was designed and configured to read from and write to the SIR to properly convert the data from parallel to SPBP serial and vice versa. It is found that separation of data for use by each SPBP bus and synchronization of data tranfer throughout the entire experimental flight system are major problems which require solution in DIU design. The techniques used to accomplish these new data interface requirements are described.

  18. FLOSYS--a web-accessible workflow system for protocol-driven biomolecular sequence analysis.

    PubMed

    Badidi, E; Lang, B F; Burger, G

    2004-11-01

    FLOSYS is an interactive web-accessible bioinformatics workflow system designed to assist biologists in multi-step data analyses. FLOSYS allows the user to create complex analysis pathways (protocols) graphically, similar to drawing a flowchart: icons representing particular bioinformatics tools are dragged and dropped onto a canvas and lines connecting those icons are drawn to specify the relationships between the tools. In addition, FLOSYS permits to select input-data, execute the protocol and store the results in a personal workspace. The three-tier architecture of FLOSYS has been implemented in Java and uses a relational database system together with new technologies for distributed and web computing such as CORBA, RMI, JSP and JDBC. The prototype of FLOSYS, which is part of the bioinformatics workbench AnaBench, is accessible on-line at http://malawimonas.bcm.umontreal.ca: 8091/anabench. The entire package is available on request to academic groups who wish to have a customized local analysis environment for research or teaching.

  19. Handheld access to radiology teaching files: an automated system for format conversion and content creation

    NASA Astrophysics Data System (ADS)

    Raman, Raghav; Raman, Lalithakala; Raman, Bhargav; Gold, Garry; Beaulieu, Christopher F.

    2002-05-01

    Current handheld Personal Digital Assistants (PDAs) can be used to view radiology teaching files. We have developed a toolkit that allows rapid creation of radiology teaching files in handheld formats from existing repositories. Our toolkit incorporated a desktop converter, a web conversion server and an application programming interface (API). Our API was integrated with an existing pilot teaching file database. We evaluated our system by obtaining test DICOM and JPEG images from our PACS system, our pilot database and from personal collections and converting them on a Windows workstation (Microsoft, Redmond, CA) and on other platforms using the web server. Our toolkit anonymized, annotated and categorized images using DICOM header information and data entered by the authors. Image processing was automatically customized for the target handheld device. We used freeware handheld image viewers as well as our custom applications that allowed window/level manipulation and viewing of additional textual information. Our toolkit provides desktop and web access to image conversion tools to produce organized handheld teaching file packages for most handheld devices and our API allows existing teaching file databases to incorporate handheld compatibility. The distribution of radiology teaching files on PDAs can increase the accessibility to radiology teaching.

  20. Enhancing Access to NASA Data via Seamless Integration Into Decision Support Systems: two Examples

    NASA Astrophysics Data System (ADS)

    Teng, W.; Rui, H.; Rishe, N.; Tetrault, R.

    2005-12-01

    The amount and variety of information that can be extracted from NASA satellite data form a rich resource that is largely untapped by the applications user community. In part, this is because of the complexity and cost of using such data. Many approaches, such as subsetting, have been taken to ameliorate this situation. Mostly, however, they have not sufficiently addressed the core needs of the applications community. The latter is generally not interested in the data per se (e.g., how they are processed), but rather in the specific measurements (e.g., surface rain) from the data, which can be infused in some decision support system. These measurements should ideally be seamlessly accessible. To rapidly bridge the gap between NASA information systems and services and the practical needs of the applications (and research) community, the Goddard Earth Sciences Data and Information Services Center (GES DISC) has collaborated with the Florida International University High Performance Database Research Center (FIU HPDRC) and the U.S. Department of Agriculture Foreign Agricultural Service (USDA FAS) to demonstrate the feasibility of making NASA data more easily and seamlessly accessible via the Web, from within the FIU's TerraFly and the FAS' Crop Explorer environments, respectively. TerraFly currently serves a broad segment of the research and applications community (some 10,000 unique users per day), by facilitating the access to various textual, remotely sensed, and vector data. Crop Explorer is the primary decision support tool used by the FAS analysts to monitor the production, supply, and demand of agricultural commodities worldwide. The key NASA information system providing the data integrated into TerraFly and Crop Explorer is the GES DISC Interactive Online Visualization and Analysis Infrastructure (Giovanni), which enables users to easily and quickly obtain science information from the data, without having to download and handle large amounts of data. The