Science.gov

Sample records for multipoint distribution system

  1. A Robust Distributed Multipoint Fiber Optic Gas Sensor System Based on AGC Amplifier Structure.

    PubMed

    Zhu, Cunguang; Wang, Rende; Tao, Xuechen; Wang, Guangwei; Wang, Pengpeng

    2016-01-01

    A harsh environment-oriented distributed multipoint fiber optic gas sensor system realized by automatic gain control (AGC) technology is proposed. To improve the photoelectric signal reliability, the electronic variable gain can be modified in real time by an AGC closed-loop feedback structure to compensate for optical transmission loss which is caused by the fiber bend loss or other reasons. The deviation of the system based on AGC structure is below 4.02% when photoelectric signal decays due to fiber bending loss for bending radius of 5 mm, which is 20 times lower than the ordinary differential system. In addition, the AGC circuit with the same electric parameters can keep the baseline intensity of signals in different channels of the distributed multipoint sensor system at the same level. This avoids repetitive calibrations and streamlines the installation process. PMID:27483267

  2. A Robust Distributed Multipoint Fiber Optic Gas Sensor System Based on AGC Amplifier Structure

    PubMed Central

    Zhu, Cunguang; Wang, Rende; Tao, Xuechen; Wang, Guangwei; Wang, Pengpeng

    2016-01-01

    A harsh environment-oriented distributed multipoint fiber optic gas sensor system realized by automatic gain control (AGC) technology is proposed. To improve the photoelectric signal reliability, the electronic variable gain can be modified in real time by an AGC closed-loop feedback structure to compensate for optical transmission loss which is caused by the fiber bend loss or other reasons. The deviation of the system based on AGC structure is below 4.02% when photoelectric signal decays due to fiber bending loss for bending radius of 5 mm, which is 20 times lower than the ordinary differential system. In addition, the AGC circuit with the same electric parameters can keep the baseline intensity of signals in different channels of the distributed multipoint sensor system at the same level. This avoids repetitive calibrations and streamlines the installation process. PMID:27483267

  3. Local multipoint distribution system (LDMS) versus free-space optical (FSO) networks

    NASA Astrophysics Data System (ADS)

    Willebrand, Heinz A.; Clark, Gerald R.; Willson, Bryan; Andreu von Euw, Christian G.; Roy, Joe; Mayhew, Laurel M.

    2001-11-01

    This paper compares two emerging broadband access methodologies, Free Space Optics (FSO) and Local Multipoint Distribution System (LMDS) and the atmospheric propagation characteristics of each when exposed to a dynamically changing channel. The comparison focuses on bandwidth, availability, and distance requirements for the new broadband market and how LMDS and FSO can be used to meet these requirements. Possible network topologies and their associated costs are examined. This comparison takes into account the total cost of deployment, including equipment costs, installation fees, access fees, and spectrum licensing fees. LMDS and FSO are compared on speed of deployment, scalability, aggregate bandwidth, and bandwidth per customer. Present and projected capabilities of each technology are considered for their suitability in different locations in the network, from the Wide Area Network (WAN), to the Metropolitan Area Network (MAN), all the way to Last Mile Access. There is a discussion on the relative performance of LMDS and FSO, focusing on the different factors that can affect link availability. Since network design is a large factor in assuring overall reliability, the flexibility of each technology with regard to network design is compared. LMDS and FSO are both line of sight, space-propagated technologies, and as such, they are both susceptible to path impediments and atmospheric attenuation, dispersion, scattering, and absorption. LMDS and FSO are affected very differently by different meteorological phenomena. Problematic atmospheric conditions are, specifically scintillation, rainfall, and fog, are examined. In addition to a discussion of these conditions, various techniques for minimizing atmospheric and environmental effects are investigated. The paper concludes with a summary of findings and recommendations for a number of broadband wireless applications.

  4. Lewis Investigates Frequency Sharing Between Future NASA Space Systems and Local Multipoint Distribution Systems in the 27-GHz Band

    NASA Technical Reports Server (NTRS)

    1997-01-01

    At the request of the Federal Communications Commission (FCC), the NASA Lewis Research Center undertook an intensive study to examine the feasibility of frequency sharing between future NASA space services and proposed Local Multipoint Distribution Systems (LMDS) in the 25.25- to 27.5-GHz band. This follows NASA's earlier involvement in the FCC's 1994 Negotiated Rule Making Committee which studied frequency sharing between Ka-band Fixed Satellite Services and LMDS in the 27.5- to 29.5-GHz band. LMDS is a terrestrial, cellular, wireless communication service primarily intended to provide television distribution from hub stations located within relatively small cells to fixed subscriber receivers. Some proposed systems, however, also plan to offer interactive services via subscriber-to-hub transmissions. LMDS providers anticipate that their systems will be a cost-effective alternative to cable television systems, especially in urban areas. LMDS proponents have expressed an interest in using frequencies below 27.5 GHz. NASA, however, plans to operate three types of space systems below 27.5 GHz. The H, I, and J follow-on satellites for the Tracking and Data Relay Satellite System (TDRSS), which are planned for launch beginning in 1999, are designed to receive high-data-rate transmissions (up to 800 Mbps) from low-Earth orbiting "user" spacecraft in the 25.25- to 27.5-GHz band. In this case, the potential interference is the aggregate interference from LMDS transmitters (both hubs and subscribers) into the TDRSS tracking receive beams as they sweep over the Earth's surface while tracking lower altitude user spacecraft.

  5. Distributed strain measurement system in one-dimensional by means of multipoint FBG sensing

    NASA Astrophysics Data System (ADS)

    Yin, Hao; Zhu, Jun; Tang, Haiyu; Wang, Hui; Zhang, Zhao; Shui, Tao; Yu, Benli

    2013-12-01

    In this paper, we described a distributed strain measurement scheme in one-dimensional. The sensing information of FBG is demodulated by a CCD spectrometer, the discrete strain is achieved by fitting and processing discrete signal demodulated utilizing labVIEW virtual instrument technology. Then it could be achieved by Using polynomial fitting method to one-dimensional discrete strain distributed detection. Experimentally, measurement was implemented in Cantilever to prove the system performance. The experimental result shows that the system can reflect the strain distribution in one-dimensional and an order strain modal characteristics of cantilever accurately. The detection system can achieve real-time and dynamic measurements, the response time for 2kHz, the response accuracy for 4μɛ.

  6. Multipoint dynamically reconfigure adaptive distributed fiber optic acoustic emission sensor (FAESense) system for condition based maintenance

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Prohaska, John; Kempen, Connie; Esterkin, Yan; Sun, Sunjian; Krishnaswamy, Sridhar

    2010-09-01

    This paper describes preliminary results obtained under a Navy SBIR contract by Redondo Optics Inc. (ROI), in collaboration with Northwestern University towards the development and demonstration of a next generation, stand-alone and fully integrated, dynamically reconfigurable, adaptive fiber optic acoustic emission sensor (FAESense™) system for the in-situ unattended detection and localization of shock events, impact damage, cracks, voids, and delaminations in new and aging critical infrastructures found in ships, submarines, aircraft, and in next generation weapon systems. ROI's FAESense™ system is based on the integration of proven state-of-the-art technologies: 1) distributed array of in-line fiber Bragg gratings (FBGs) sensors sensitive to strain, vibration, and acoustic emissions, 2) adaptive spectral demodulation of FBG sensor dynamic signals using two-wave mixing interferometry on photorefractive semiconductors, and 3) integration of all the sensor system passive and active optoelectronic components within a 0.5-cm x 1-cm photonic integrated circuit microchip. The adaptive TWM demodulation methodology allows the measurement of dynamic high frequnency acoustic emission events, while compensating for passive quasi-static strain and temperature drifts. It features a compact, low power, environmentally robust 1-inch x 1-inch x 4-inch small form factor (SFF) package with no moving parts. The FAESense™ interrogation system is microprocessor-controlled using high data rate signal processing electronics for the FBG sensors calibration, temperature compensation and the detection and analysis of acoustic emission signals. Its miniaturized package, low power operation, state-of-the-art data communications, and low cost makes it a very attractive solution for a large number of applications in naval and maritime industries, aerospace, civil structures, the oil and chemical industry, and for homeland security applications.

  7. Multi-Point Combustion System: Final Report

    NASA Technical Reports Server (NTRS)

    Goeke, Jerry; Pack, Spencer; Zink, Gregory; Ryon, Jason

    2014-01-01

    A low-NOx emission combustor concept has been developed for NASA's Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 lb thrust engine application. These goals include 75 percent reduction of LTO NOx from CAEP6 standards without increasing CO, UHC, or smoke from that of current state of the art. An additional key factor in this work is to improve lean combustion stability over that of previous work performed on similar technology in the early 2000s. The purpose of this paper is to present the final report for the NASA contract. This work included the design, analysis, and test of a multi-point combustion system. All design work was based on the results of Computational Fluid Dynamics modeling with the end results tested on a medium pressure combustion rig at the UC and a medium pressure combustion rig at GRC. The theories behind the designs, results of analysis, and experimental test data will be discussed in this report. The combustion system consists of five radially staged rows of injectors, where ten small scale injectors are used in place of a single traditional nozzle. Major accomplishments of the current work include the design of a Multipoint Lean Direct Injection (MLDI) array and associated air blast and pilot fuel injectors, which is expected to meet or exceed the goal of a 75 percent reduction in LTO NOx from CAEP6 standards. This design incorporates a reduced number of injectors over previous multipoint designs, simplified and lightweight components, and a very compact combustor section. Additional outcomes of the program are validation that the design of these combustion systems can be aided by the use of Computational Fluid Dynamics to predict and reduce emissions. Furthermore, the staging of fuel through the individually controlled radially staged injector rows successfully demonstrated improved low power operability as well as improvements in emissions over previous multipoint designs. Additional comparison

  8. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    PubMed Central

    Nascimento, Jehan F.; Silva, Marcionilo J.; Coêlho, Isnaldo J. S.; Cipriano, Eliel; Martins-Filho, Joaquim F.

    2012-01-01

    We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations. PMID:22737017

  9. Low-delay center-bridged and distributed combining schemes for multipoint videoconferencing

    NASA Astrophysics Data System (ADS)

    Chen, Ting-Chung; Wang, Wen-deh

    1994-09-01

    Multipoint videoconferencing is a natural evolution of two-point videoconferencing and can increase its value to users. Currently, ITU-T's SG8 and SG15 are working on multipoint control related issues; ANSI's T1A1.5 is also working in this area. The video coding and related communication standards of the upcoming MPEG4 and H.26P will all include multipoint communication capability. This paper investigates transport structures and the associated combining schemes that can be used to support multipoint videoconferencing. Since low delay is a major issue for multipoint interactive communications, a distributed structure which renders the lowest delay with many other system advantages is especially investigated. We first analyze the insertion delay of a QCIF combiner bridge which have been proposing for multipoint videoconferencing. Partial input-output pipelining has been used to reduce the delay. To reduce the insertion delay caused by unevenly distributed inputs, a parallel parsing scheme is proposed. This parallel parsing scheme allows low complexity inputs not to be held up by high complexity inputs and can reduce insertion delay significantly. An efficient delay- reduction algorithm using intraslice coding was also cited in a previous proposal. As a comparison, we describe low delay pel-domain transcoding schemes which have similar delay performance with coded-domain combining but have much higher complexities. We also describe a recent proposal which eliminates most of the insertion delay but which require major changes to existing standards and encoder and decoder implementations. The performance of a distributed transport structure in providing multipoint video services is then investigated. Using the face that bandwidth usage is an important factor in estimating network complexity, it is shown that a distributed transport structure saves 40 to 62.5% bandwidth for a 4-point conferencing and also renders the shortest delay when compared with other center

  10. Alternative licensing arrangements and spectrum economics: The case of multipoint distribution service

    NASA Technical Reports Server (NTRS)

    Agnew, C. E.

    1981-01-01

    At present, the Federal Communications Commission assigns radio licenses following a determination of the public interest. Whenever mutually conflicting license applications are filed, the Commission holds a comparative hearing. This assignment mechanism is criticized as cumbersome and unrealiable, and three alternatives are proposed: increasing the available spectrum, and either auctions or lotteries of radio licenses. An analysis is presented of the present system and these alternative arrangments for assigning rights to the frequency spectrum for the Multipoint Distribution Service (MDS). Although MDS is a relatively minor radio service, it serves as a prototype for message distribution services with a large potential for use in business communications. Moreover, the way in which the initial batch of MDS licenses was assigned provides a unique opportunity for empirical work on the economics of the licensing process.

  11. Multipoint Multimedia Conferencing System with Group Awareness Support and Remote Management

    ERIC Educational Resources Information Center

    Osawa, Noritaka; Asai, Kikuo

    2008-01-01

    A multipoint, multimedia conferencing system called FocusShare is described that uses IPv6/IPv4 multicasting for real-time collaboration, enabling video, audio, and group awareness information to be shared. Multiple telepointers provide group awareness information and make it easy to share attention and intention. In addition to pointing with the…

  12. Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System

    DOE Data Explorer

    Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

    2016-08-12

    This public data set contains openly-documented, machine readable digital research data corresponding to figures published in G.M. Bodner et al., 'Control and Automation of the Pegasus Multi-point Thomson Scattering System,' Rev. Sci. Instrum. 87, 11E523 (2016).

  13. Characterization of Miniature Millimeter-Wave Vivaldi Antenna for Local Multipoint Distribution Service

    NASA Technical Reports Server (NTRS)

    Simon, Rainee N.; Lee, Richard Q.

    1997-01-01

    The paper presents first, an efficient measurement technique to characterize the input impedance of a Vivaldi antenna, second, a simple technique to impedance match a Vivaldi antenna to a 50 Ohm feed line and lastly, a desktop arrangement to determine the directional gain of a Vivaldi antenna. The characterization is done using a microwave wafer probe station, a ground-signal microwave probe, impedance standard substrate and an automatic network analyzer. The Vivaldi antenna with a matching transformer has a VSVIR close to unity and a gain of about 10 dB over the frequency band of 27.5 to 28.35 GHz which is allocated for local multipoint distribution service (LMDS).

  14. Micro-Hole Multi-Point Punching System Using Punch and Die Made by EDM

    NASA Astrophysics Data System (ADS)

    Broomfield, Mark; Mori, Toshihiko; Mikuriya, Teruaki; Tachibana, Kazushi

    In this research a multi-point micro punch and die system was developed. The process of electric discharge machining (EDM) was used to produce both the punch and die. The punches were machined from a 5 mm diameter tungsten and a 10 mm diameter tool steel round rods by wire electric discharge machining (WEDM), using a 200 µm diameter wire electrode. The die holes were made using the punch as the electrode. The EDM process of the holes was carried out on a newly developed desktop EDM machine. The punch and die placed on a micro-die set and then on a micro press were used to produce micro-holes using an automatic control system developed for this process. Experiments to produce 50 µm to 67 µm square micro-holes on 50 µm thick aluminum, 30 µm thick copper and 20 µm thick stainless steel foils were conducted. The capabilities of multi-point punching using the tungsten punch and a tool steel punch were examined and tungsten was chosen as the material of choice for making the punch tool. A scanning electron microscope confirmed that the holes produced are clean, and the sheared surfaces smooth. The punch tool showed no signs of deformation or cracks even after repeated punching.

  15. A synchronized multipoint vision-based system for displacement measurement of civil infrastructures.

    PubMed

    Ho, Hoai-Nam; Lee, Jong-Han; Park, Young-Soo; Lee, Jong-Jae

    2012-01-01

    This study presents an advanced multipoint vision-based system for dynamic displacement measurement of civil infrastructures. The proposed system consists of commercial camcorders, frame grabbers, low-cost PCs, and a wireless LAN access point. The images of target panels attached to a structure are captured by camcorders and streamed into the PC via frame grabbers. Then the displacements of targets are calculated using image processing techniques with premeasured calibration parameters. This system can simultaneously support two camcorders at the subsystem level for dynamic real-time displacement measurement. The data of each subsystem including system time are wirelessly transferred from the subsystem PCs to master PC and vice versa. Furthermore, synchronization process is implemented to ensure the time synchronization between the master PC and subsystem PCs. Several shaking table tests were conducted to verify the effectiveness of the proposed system, and the results showed very good agreement with those from a conventional sensor with an error of less than 2%.

  16. Public Data Set: A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment

    DOE Data Explorer

    Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586)

    2016-08-13

    This public data set contains openly-documented, machine readable digital research data corresponding to figures published in D.J. Schlossberg et. al., 'A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment,' accepted for publication in Review of Scientific Instruments.

  17. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    PubMed

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  18. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts

    NASA Astrophysics Data System (ADS)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  19. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    PubMed

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests. PMID:27475551

  20. Public Data Set: Erratum: "Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment" [Rev. Sci. Instrum. 83, 10D516 (2012)

    DOE Data Explorer

    Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448); Winz, Gregory R. [University of Wisconsin-Madison] (ORCID:0000000177627184)

    2016-07-18

    This data set contains openly-documented, machine readable digital research data corresponding to figures published in M.G. Burke et al., 'Erratum: "Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment" [Rev. Sci. Instrum. 83, 10D516 (2012)],' Rev. Sci. Instrum. 87, 079902 (2016).

  1. Formulation of Multiple Diffraction by Trees and Buildings for Radio Propagation Predictions for Local Multipoint Distribution Service

    PubMed Central

    Zhang, Wei

    1999-01-01

    This paper presents a closed-form expression for multiple forward diffraction by rows of tree canopies and buildings applicable to the propagation predictions at centimeter and millimeter wavelengths for local multipoint distribution service (LMDS). The expression is derived from the uniform geometrical theory of diffraction and physical optics, as well as from some existing models for vegetation and buildings. When the transmitter antennas are sufficiently high, the attenuation of the buildings varies around the value of free space and the building effect is negligible, because a line-of-sight (LOS) propagation path between transmitter and over building-rooftop receiver antennas exists and plays a major role. The tree canopies which extend above the building rooftop heights block the LOS propagation path and cause additional signal attenuation. An existing study of the LMDS radio channel based on measurements came to the same conclusion. The attenuation effect of the buildings is significant if the transmitter antennas are not high enough.

  2. Non-stationary corona around multi-point system in atmospheric electric field: I. Onset electric field and discharge current

    NASA Astrophysics Data System (ADS)

    Bazelyan, E. M.; Raizer, Yu. P.; Aleksandrov, N. L.

    2014-03-01

    The properties of a non-stationary glow corona maintained near the tips of a multi-point ground system in a time-varying thundercloud electric field have been studied numerically and analytically. Computer and analytical models were developed to simulate the corona discharge initiated from a system of identical vertical conductive electrodes distributed uniformly over a grounded plane surface. The simulation was based on a solution of the electrostatic equation for electric field and continuity equations for light and aerosol ions. The development of individual corona space charge layers from different points and the formation of a united plane layer were considered. The effect of system dimensions and that of the distance between electrodes on the external electric field corresponding to corona onset near the rod tips was investigated. The evolution in time of the corona current was calculated for systems with various numbers of coronating rods in time-varying atmospheric electric field. In the limit of infinite number of coronating rods, reasonable agreement was obtained between numerical calculations and analytical theory considering the effect of surrounding rods on the corona discharge from a given rod in a simplified integral way. Conditions were determined under which the corona properties of a multi-point system are similar to the properties of a plane surface emitting ions into the atmosphere. In this case, the corona current density is governed by the time derivative of the thundercloud electric field and is independent of the ion mobility and of the coronating system dimensions. The total corona space charge injected into the atmosphere per unit area by a given instant is controlled by the thundercloud electric field at this instant and depends on the geometrical parameters of the system only indirectly, through the corona onset atmospheric electric field. This simple model could be used to simulate a corona discharge during thunderstorms at the earth

  3. A synchronized multipoint vision-based system for displacement measurement of civil infrastructures.

    PubMed

    Ho, Hoai-Nam; Lee, Jong-Han; Park, Young-Soo; Lee, Jong-Jae

    2012-01-01

    This study presents an advanced multipoint vision-based system for dynamic displacement measurement of civil infrastructures. The proposed system consists of commercial camcorders, frame grabbers, low-cost PCs, and a wireless LAN access point. The images of target panels attached to a structure are captured by camcorders and streamed into the PC via frame grabbers. Then the displacements of targets are calculated using image processing techniques with premeasured calibration parameters. This system can simultaneously support two camcorders at the subsystem level for dynamic real-time displacement measurement. The data of each subsystem including system time are wirelessly transferred from the subsystem PCs to master PC and vice versa. Furthermore, synchronization process is implemented to ensure the time synchronization between the master PC and subsystem PCs. Several shaking table tests were conducted to verify the effectiveness of the proposed system, and the results showed very good agreement with those from a conventional sensor with an error of less than 2%. PMID:23028250

  4. Multi-point laser coherent detection system and its application on vibration measurement

    NASA Astrophysics Data System (ADS)

    Fu, Y.; Yang, C.; Xu, Y. J.; Liu, H.; Yan, K.; Guo, M.

    2015-05-01

    Laser Doppler vibrometry (LDV) is a well-known interferometric technique to measure the motions, vibrations and mode shapes of machine components and structures. The drawback of commercial LDV is that it can only offer a pointwise measurement. In order to build up a vibrometric image, a scanning device is normally adopted to scan the laser point in two spatial axes. These scanning laser Doppler vibrometers (SLDV) assume that the measurement conditions remain invariant while multiple and identical, sequential measurements are performed. This assumption makes SLDVs impractical to do measurement on transient events. In this paper, we introduce a new multiple-point laser coherent detection system based on spatial-encoding technology and fiber configuration. A simultaneous vibration measurement on multiple points is realized using a single photodetector. A prototype16-point laser coherent detection system is built and it is applied to measure the vibration of various objects, such as body of a car or a motorcycle when engine is on and under shock tests. The results show the prospect of multi-point laser coherent detection system in the area of nondestructive test and precise dynamic measurement.

  5. Multi-point contact of the high-speed vehicle-turnout system dynamics

    NASA Astrophysics Data System (ADS)

    Ren, Zunsong

    2013-05-01

    The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn't occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.

  6. Single and multi-point ion energy distributions in a VHF+RF commercial plasma reactor measured by novel in-wafer ion energy analyzer

    NASA Astrophysics Data System (ADS)

    Lane, Barton; Funk, Merritt; Chen, Lee; Sundararajan, Radha; Zhao, Jianping

    2012-10-01

    A novel, all silicon, minimally perturbing, non-contaminating, in-wafer, 2 and 3 layer ion energy analyzer described elsewhere in this conference is used to measure ion energy distributions for a variety of realistic processing conditions in a commercial VHF + 13.56 MHZ RF reactor with no modifications to its basic geometry or RF delivery system. Spectra with energies as high 1 keV are measured with resolution on the order of 1%. We show data and discuss the splitting of the high energy peaks due to finite ion sheath crossing time effects and how this splitting scales with frequency, power and pressure. We discuss the origin of the charge exchange peaks. We use the identification of atomic and molecular oxygen ion peaks to estimate the resolution of the diagnostic. The effect of VHF in narrowing ion energy distributions and yielding moderate ion energies will be highlighted. Spectra using a multi-point, 2 layer variant of the ion energy analyzer design were obtained at 4 radial locations for a variety of conditions in argon and oxygen plasmas. These spectra quantify center to edge variations and reveal unique spectral features due to pre-existing modifications to the test reactor's upper counter electrode surface.

  7. Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment

    SciTech Connect

    Burke, M. G.; Fonck, R. J.; Bongard, M. W.; Schlossberg, D. J.; Winz, G. R.

    2012-10-15

    A passive ion temperature polychromator has been deployed on Pegasus to study power balance and non-thermal ion distributions that arise during point source helicity injection. Spectra are recorded from a 1 m F/8.6 Czerny-Turner polychromator whose output is recorded by an intensified high-speed camera. The use of high orders allows for a dispersion of 0.02 A/mm in 4th order and a bandpass of 0.14 A ({approx}13 km/s) at 3131 A in 4th order with 100 {mu}m entrance slit. The instrument temperature of the spectrometer is 15 eV. Light from the output of an image intensifier in the spectrometer focal plane is coupled to a high-speed CMOS camera. The system can accommodate up to 20 spatial points recorded at 0.5 ms time resolution. During helicity injection, stochastic magnetic fields keep T{sub e} low ({approx}100 eV) and thus low ionization impurities penetrate to the core. Under these conditions, high core ion temperatures are measured (T{sub i} Almost-Equal-To 1.2 keV, T{sub e} Almost-Equal-To 0.1 keV) using spectral lines from carbon III, nitrogen III, and boron IV.

  8. Control-volume distributed multi-point flux approximation coupled with a lower-dimensional fracture model

    NASA Astrophysics Data System (ADS)

    Ahmed, R.; Edwards, M. G.; Lamine, S.; Huisman, B. A. H.; Pal, M.

    2015-03-01

    A cell-centered control-volume distributed multi-point flux approximation (CVD-MPFA) finite-volume formulation is presented for discrete fracture-matrix simulations. The grid is aligned with the fractures and barriers which are then modeled as lower-dimensional interfaces located between the matrix cells in the physical domain. The nD pressure equation is solved in the matrix domain coupled with an (n - 1)D pressure equation solved in the fractures. The CVD-MPFA formulation naturally handles fractures with anisotropic permeabilities on unstructured grids. Matrix-fracture fluxes are expressed in terms of matrix and fracture pressures, and must be added to the lower-dimensional flow equation (called the transfer function). An additional transmission condition is used between matrix cells adjacent to low permeable fractures to link the velocity and pressure jump across the fractures. Numerical tests serve to assess the convergence and accuracy of the lower-dimensional fracture model for highly anisotropic fractures having different apertures and permeability tensors. A transport equation for tracer flow is coupled via the Darcy flux for single and intersecting fractures. The lower-dimensional approach for intersecting fractures avoids the more restrictive CFL condition corresponding to the equi-dimensional approximation with explicit time discretization. Lower-dimensional fracture model results are compared with hybrid-grid and equi-dimensional model results. Fractures and barriers are efficiently modeled by lower-dimensional interfaces which yield comparable results to those of the equi-dimensional model. Highly conductive fractures are modeled as lower-dimensional entities without the use of locally refined grids that are required by the equi-dimensional model, while pressure continuity across fractures is built into the model, without depending on the extra degrees of freedom which must be added locally by the hybrid-grid method. The lower-dimensional fracture

  9. A novel, cost-effective, multi-point Thomson scattering system on the Pegasus Toroidal Experiment (invited)

    NASA Astrophysics Data System (ADS)

    Schlossberg, D. J.; Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Reusch, J. A.; Rodriguez Sanchez, C.

    2016-11-01

    A novel, cost-effective, multi-point Thomson scattering system has been designed, implemented, and operated on the Pegasus Toroidal Experiment. Leveraging advances in Nd:YAG lasers, high-efficiency volume phase holographic transmission gratings, and increased quantum-efficiency Generation 3 image-intensified charge coupled device (ICCD) cameras, the system provides Thomson spectra at eight spatial locations for a single grating/camera pair. The on-board digitization of the ICCD camera enables easy modular expansion, evidenced by recent extension from 4 to 12 plasma/background spatial location pairs. Stray light is rejected using time-of-flight methods suited to gated ICCDs, and background light is blocked during detector readout by a fast shutter. This ˜103 reduction in background light enables further expansion to up to 24 spatial locations. The implementation now provides single-shot Te(R) for ne > 5 × 1018 m-3.

  10. Injectors for Multipoint Injection

    NASA Technical Reports Server (NTRS)

    Prociw, Lev Alexander (Inventor); Ryon, Jason (Inventor)

    2015-01-01

    An injector for a multipoint combustor system includes an inner air swirler which defines an interior flow passage and a plurality of swirler inlet ports in an upstream portion thereof. The inlet ports are configured and adapted to impart swirl on flow in the interior flow passage. An outer air cap is mounted outboard of the inner swirler. A fuel passage is defined between the inner air swirler and the outer air cap, and includes a discharge outlet between downstream portions of the inner air swirler and the outer air cap for issuing fuel for combustion. The outer air cap defines an outer air circuit configured for substantially unswirled injection of compressor discharge air outboard of the interior flow passage.

  11. Non-stationary corona around multi-point system in atmospheric electric field: II. Altitude and time variation of electric field

    NASA Astrophysics Data System (ADS)

    Bazelyan, E. M.; Raizer, Yu. P.; Aleksandrov, N. L.

    2014-03-01

    The vertical electric field profile during thunderstorms was studied numerically and analytically above the plane ground surface with irregularities that generated ions when the surface electric field was sufficient for ion emission. The computer model of a plane emitting ions into the atmosphere simulated a limiting case of a non-stationary glow corona occurring near the tips of a multi-point ground system in a time-varying thundercloud electric field. The evolution of electric field profiles for various rates of change of thundercloud electric field was analyzed and the peculiarities of electric field measurements during thunderstorms were considered. A computer model was developed to estimate the temporal evolution of electric field above a multi-point coronating system. Conditions under which the electric field evolution above a multi-electrode system is similar to that above a plane emitting surface were determined. The evolution of the surface electric field below coronating points in a multi-electrode system was calculated. Conditions when the surface electric field tends to the thundercloud electric field necessary for corona onset in a multi-point system were obtained.

  12. Three-dimensional control-volume distributed multi-point flux approximation coupled with a lower-dimensional surface fracture model

    NASA Astrophysics Data System (ADS)

    Ahmed, Raheel; Edwards, Michael G.; Lamine, Sadok; Huisman, Bastiaan A. H.; Pal, Mayur

    2015-12-01

    A novel cell-centred control-volume distributed multi-point flux approximation (CVD-MPFA) finite-volume formulation is presented for discrete fracture-matrix simulations on unstructured grids in three-dimensions (3D). The grid is aligned with fractures and barriers which are then modelled as lower-dimensional surface interfaces located between the matrix cells in the physical domain. The three-dimensional pressure equation is solved in the matrix domain coupled with a two-dimensional (2D) surface pressure equation solved over fracture networks via a novel surface CVD-MPFA formulation. The CVD-MPFA formulation naturally handles fractures with anisotropic permeabilities on unstructured grids. Matrix-fracture fluxes are expressed in terms of matrix and fracture pressures and define the transfer function, which is added to the lower-dimensional flow equation and couples the three-dimensional and surface systems. An additional transmission condition is used between matrix cells adjacent to low permeable fractures to couple the velocity and pressure jump across the fractures. Convergence and accuracy of the lower-dimensional fracture model is assessed for highly anisotropic fractures having a range of apertures and permeability tensors. A transport equation for tracer flow is coupled via the Darcy flux for single and intersecting fractures. The lower-dimensional approximation for intersecting fractures avoids the more restrictive CFL condition corresponding to the equi-dimensional approximation with explicit time discretisation. Lower-dimensional fracture model results are compared with equi-dimensional model results. Fractures and barriers are efficiently modelled by lower-dimensional interfaces which yield comparable results to those of the equi-dimensional model. Pressure continuity is built into the model across highly conductive fractures, leading to reduced local degrees of freedom in the CVD-MPFA approximation. The formulation is applied to geologically complex

  13. Novel implantable imaging system for enabling simultaneous multiplanar and multipoint analysis for fluorescence potentiometry in the visual cortex.

    PubMed

    Kobayashi, Takuma; Motoyama, Mayumi; Masuda, Hiroyuki; Ohta, Yasumi; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Tamura, Hideki; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

    2012-01-01

    Techniques for fast, noninvasive measurement of neuronal excitability within a broad area will be of major importance for analyzing and understanding neuronal networks and animal behavior in neuroscience field. In this research, a novel implantable imaging system for fluorescence potentiometry was developed using a complementary metal-oxide semiconductor (CMOS) technology, and its application to the analysis of cultured brain slices and the brain of a living mouse is described. A CMOS image sensor, small enough to be implanted into the brain, with light-emitting diodes and an absorbing filter was developed to enable real-time fluorescence imaging. The sensor, in conjunction with a voltage-sensitive dye, was certainly able to visualize the potential statuses of neurons and obtain physiological responses in both right and left visual cortex simultaneously by using multiple sensors for the first time. This accomplished multiplanar and multipoint measurement provides multidimensional information from different aspects. The light microsensors do not disturb the animal behavior. This implies that the imaging system can combine functional fluorescence imaging in the brain with behavioral experiments in a freely moving animal.

  14. Multi-point injection: A general purpose delivery system for treatment and containment of hazardous and radiological waste

    SciTech Connect

    Kauschinger, J.L.; Kubarewicz, J.; Van Hoesen, S.D.

    1997-12-31

    The multi-point injection (MPI) technology is a proprietary jetting process for the in situ delivery of various agents to treat radiological and/or chemical wastes. A wide variety of waste forms can be treated, varying from heterogeneous solid waste dumped into shallow burial trenches, bottom sludge (heel material) inside of underground tanks, and contaminated soils with widely varying soil composition (gravel, silts/clays, soft rock). The robustness of the MPI system is linked to the use of high speed mono-directional jets to deliver various types of agents for a variety of applications, such as: pretreatment of waste prior to insitu vitrification, solidification of waste for creating low conductivity monoliths, oxidants for insitu destruction of organic waste, and grouts for creating barriers (vertical, inclined, and bottom seals). The only strict limitation placed upon the MPI process is that the material can be pumped under high pressure. This paper describes the procedures to inject ordinary grout to form solidified monoliths of solid wastes.

  15. Optimal use of buffer volumes for the measurement of atmospheric gas concentration in multi-point systems

    NASA Astrophysics Data System (ADS)

    Cescatti, Alessandro; Marcolla, Barbara; Goded, Ignacio; Gruening, Carsten

    2016-09-01

    Accurate multi-point monitoring systems are required to derive atmospheric measurements of greenhouse gas concentrations both for the calculation of surface fluxes with inversion transport models and for the estimation of non-turbulent components of the mass balance equation (i.e. advection and storage fluxes) at eddy covariance sites. When a single analyser is used to monitor multiple sampling points, the deployment of buffer volumes (BVs) along sampling lines can reduce the uncertainty due to the discrete temporal sampling of the signal. In order to optimize the use of buffer volumes we explored various set-ups by simulating their effect on time series of high-frequency CO2 concentration collected at three Fluxnet sites. Besides, we proposed a novel scheme to calculate half-hourly weighted arithmetic means from discrete point samples, accounting for the probabilistic fraction of the signal generated in the averaging period. Results show that the use of BVs with the new averaging scheme reduces the mean absolute error (MAE) up to 80 % compared to a set-up without BVs and up to 60 % compared to the case with BVs and a standard, non-weighted averaging scheme. The MAE of CO2 concentration measurements was observed to depend on the variability of the concentration field and on the size of BVs, which therefore have to be carefully dimensioned. The optimal volume size depends on two main features of the instrumental set-up: the number of measurement points and the time needed to sample at one point (i.e. line purging plus sampling time). A linear and consistent relationship was observed at all sites between the sampling frequency, which summarizes the two features mentioned above, and the renewal frequency associated with the volume. Ultimately, this empirical relationship can be applied to estimate the optimal volume size according to the technical specifications of the sampling system.

  16. Development of a Multi-Point Pyrometer System (MPPS) for measuring surface temperature and emissivity

    SciTech Connect

    Benton, R.D.; Jang, Ping-Rey

    1993-06-01

    In support of the US DOE MHD research program, the Diagnostic Instrumentation and Analysis Laboratory (DIAL) has been actively engaged in developing and applying advanced optical diagnostic techniques and instrumentation systems to high temperature coal-fired gas streams for over a decade. One of the earliest diagnostic systems developed by DIAL was a two color pyrometer (TCP). In this system, two commercial single-color pyrometers and a microprocessor system were used to form a TCP which can make accurate measurements of surfaces of unknown emissivity and temperature. This system has been used extensively to make measurements in support of the national MHD program. This report describes this system.

  17. Control and automation of the Pegasus multi-point Thomson scattering system

    DOE PAGES

    Bodner, Grant M.; Bongard, Michael W.; Fonck, Raymond J.; Reusch, Joshua A.; Rodriguez Sanchez, C.; Schlossberg, David J.

    2016-08-12

    A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. In addition, the system has been upgraded with a set of fast (~1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

  18. Control and automation of the Pegasus multi-point Thomson scattering system

    NASA Astrophysics Data System (ADS)

    Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Reusch, J. A.; Rodriguez Sanchez, C.; Schlossberg, D. J.

    2016-11-01

    A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. Additionally, the system has been upgraded with a set of fast (˜1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

  19. Dynamics modeling of multibody flexible systems with traveling multi-point joints

    NASA Technical Reports Server (NTRS)

    Messac, Achille; Herman, Deborah

    1991-01-01

    This paper presents a general methodology for modeling the dynamics of a flexible structure which moves on the surface of another flexible structure. The relative motion of the two bodies need not follow a straight line, nor need the contact surfaces be planar in their undeformed state. A model reduction approach is also developed, which makes the methodology applicable to large structural systems. The Space Station Freedom Mobile Transporter represents one such system, when attached to the Shuttle Orbiter. Numerical examples are provided.

  20. Multi-Point Thomson Scattering System Calibration and Measurements on HBT-EP

    NASA Astrophysics Data System (ADS)

    Donald, G. V.; Levesque, J. P.; Stoafer, C. C.; Mauel, M. E.

    2015-11-01

    A Thomson scattering (TS) system has been successfully installed and calibrated for diagnostics of HBT-EP. The TS system provides three spatial point measurements and has significantly improved upon the previous single point system. Analysis of Rayleigh Scattering was performed for an absolute density calibration of the TS system. Energy fluctuations in the output pulse from the Nd:YAG laser are individually recorded and accounted for using an integrating sphere and photodetector. Te and ne profiles have been investigated for varying wall configuration changes, including insertion of ferritic wall elements. We report our results, for the three spatial points, and measurements of the Te and ne evolution through typical HBT-EP discharges. The three fiber bundle system will be upgraded within the next grant period to allow measurement of ten spatial points. The ten point system will enhance our equilibrium reconstruction capability, improve stability analysis of the HBT-EP discharges, and allow for further understanding of the plasma characteristics during resistive wall mode (RWM) activity and active control experiments. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  1. Proceedings of the Workshop on Applications of Distributed System Theory to the Control of Large Space Structures

    NASA Technical Reports Server (NTRS)

    Rodriguez, G. (Editor)

    1983-01-01

    Two general themes in the control of large space structures are addressed: control theory for distributed parameter systems and distributed control for systems requiring spatially-distributed multipoint sensing and actuation. Topics include modeling and control, stabilization, and estimation and identification.

  2. Structure, Stability and Emissions of Lean Direct Injection Combustion, including a Novel Multi-Point LDI System for NOx Reduction

    NASA Astrophysics Data System (ADS)

    Villalva Gomez, Rodrigo

    Experimental research on Lean Direct Injection (LDI) combustors for gas turbine applications is presented. LDI combustion is an alternative to lean premixed combustion which has the potential of equivalent reduction of oxides of nitrogen (NOx) emissions and of peak combustor exit temperatures, but without some drawbacks of premixed combustors, such as flashback and autoignition. Simultaneous observations of the velocity field and reaction zone of an LDI swirl-stabilized combustor with a mixing tube at atmospheric conditions, with the goal of studying the flame stabilization mechanism, are shown. The flame was consistently anchored at the shear layer formed by the high-speed reactants exiting the mixing tube and the low speed recirculation region. Individual image analysis of the location of the tip of the recirculation zone and tip of the reaction region confirmed previously observed trends, but showed that calculation of the distance between these two points for corresponding image pairs yields results no different than when calculated from random image pairs. This most likely indicates a lag in the anchoring of the flame to changes in the recirculation zone, coupled with significant stochastic variation. An alternate LDI approach, multi-point LDI (MLDI), is also tested experimentally. A single large fuel nozzle is replaced by multiple small fuel nozzles to improve atomization and reduce the total volume of the high-temperature, low velocity recirculation zones, reducing NOx formation. The combustor researched employs a novel staged approach to allow good performance across a wide range of conditions by using a combination of nozzle types optimized to various power settings. The combustor has three independent fuel circuits referenced as pilot, intermediate, and outer. Emissions measurements, OH* chemiluminescence imaging, and thermoacoustic instability studies were run in a pressurized combustion facility at pressures from 2.0 to 5.3 bar. Combustor performance

  3. Multipoint observations of the spatial distribution and temporal evolution of the "Nose-like" structures in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Luo, Hao; Du, Aimin; Ge, Yasong; Cao, Xin; Zhang, Ying; Huang, Sheng

    2016-04-01

    The "Nose-like" ion spectral structures are formed by ions in the near-Earth plasma sheet penetrating into the inner magnetosphere. Many studies had shown that the distribution of the Nose structures was controlled by the large-scale convection electric field, gradient-curvature drift and corotation electric field in the inner magnetosphere during geomagnetic quiet condition. However, during geomagnetic active periods, especially during the storms and substorms, the spatial and temporal characteristics and formation mechanism of different ions are still under debate. In this study, joint observations from Van Allen Probes, THEMIS, and Cluster will be used to statistically study the spatial distribution and temporal evolution of the "Nose-like" ion spectral structures in the inner magnetosphere. Backward tracing method based on Weimer 96 electric field and dipole magnetic field model was applied to simulate the ion structures and compared to the observations. The results show some important characteristics of the ion structures and will help us understand the injection mechanism of the ions from the plasma sheet into the inner magnetosphere and the relation between the storm and substorm, and thus provide important information for ring current formation.

  4. Fluid sample collection and distribution system. [qualitative analysis of aqueous samples from several points

    NASA Technical Reports Server (NTRS)

    Brooks, R. L. (Inventor)

    1979-01-01

    A multipoint fluid sample collection and distribution system is provided wherein the sample inputs are made through one or more of a number of sampling valves to a progressive cavity pump which is not susceptible to damage by large unfiltered particles. The pump output is through a filter unit that can provide a filtered multipoint sample. An unfiltered multipoint sample is also provided. An effluent sample can be taken and applied to a second progressive cavity pump for pumping to a filter unit that can provide one or more filtered effluent samples. The second pump can also provide an unfiltered effluent sample. Means are provided to periodically back flush each filter unit without shutting off the whole system.

  5. SLM-based multipoint vibrometry

    NASA Astrophysics Data System (ADS)

    Haist, Tobias; Tarbeyevskaya, Alena; Warber, Michael; Osten, Wolfgang; Rembe, Christian; Ludwig, Mario; Stork, Wilhelm

    2011-05-01

    Heterodyne interferometry is a very accurate and robust technique for measuring vibrations under industrial conditions. Typically, instruments based on this principle measure on a single point and scanning is employed to obtain operational deflection shapes. For the simultaneous measurement of vibrations (e.g. to detect transients) it is possible to use a fixed arrangement of measurement beams. Dynamic steering of multiple beams, however, is not easy to achieve. In this contribution we present a solution for multipoint vibrometry using a high resolution (HDTV) programmable spatial light modulator as the core element. By using a liquid crystal display (LCD) for displaying a dynamic hologram it is possible to independently control multiple measurement spots in three dimensions with high repeatability and accuracy. Mechanical movements that might introduce noise do not oocur. The main challenge in designing such an LCD-based multipoint vibrometer is to avoid problems due to the unwanted spurious diffraction orders that will be present when using commercially available spatial light modulators for reconstructing holograms. We present a system in which the illuminating as well as the detection is programmable. One half of the high resolution LCD is used for illumination and the other half is responsible for the detection. Different possible methods to avoid spurious diffraction orders are shortly discussed. Emphasis will be laid on a method based on complex multiplexing (using hologram optimization) and a spatial multiplexing method based on Golay arrays. We show the optical design as well as first experimental results for a single detector. Hologram computation is based on a joint optimization of the detection and the illumination hologram using a modified Gerchberg-Saxton algorithm together with combinatorial optimization of the spot/detector mapping.

  6. Single-pulse Multi-point Multi-component Interferometric Rayleigh Scattering Velocimeter

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Lee, Joseph W.; Gaffney, Richard L., Jr.; Cutler, Andrew W.

    2006-01-01

    A simultaneous multi-point, multi-component velocimeter using interferometric detection of the Doppler shift of Rayleigh, Mie, and Rayleigh-Brillouin scattered light in supersonic flow is described. The system uses up to three sets of collection optics and one beam combiner for the reference laser light to form a single collimated beam. The planar Fabry-Perot interferometer used in the imaging mode for frequency detection preserves the spatial distribution of the signal reasonably well. Single-pulse multi-points measurements of up to two orthogonal and one non-orthogonal components of velocity in a Mach 2 free jet were performed to demonstrate the technique. The average velocity measurements show a close agreement with the CFD calculations using the VULCAN code.

  7. Scalar discrete nonlinear multipoint boundary value problems

    NASA Astrophysics Data System (ADS)

    Rodriguez, Jesus; Taylor, Padraic

    2007-06-01

    In this paper we provide sufficient conditions for the existence of solutions to scalar discrete nonlinear multipoint boundary value problems. By allowing more general boundary conditions and by imposing less restrictions on the nonlinearities, we obtain results that extend previous work in the area of discrete boundary value problems [Debra L. Etheridge, Jesus Rodriguez, Periodic solutions of nonlinear discrete-time systems, Appl. Anal. 62 (1996) 119-137; Debra L. Etheridge, Jesus Rodriguez, Scalar discrete nonlinear two-point boundary value problems, J. Difference Equ. Appl. 4 (1998) 127-144].

  8. FRIB cryogenic distribution system

    SciTech Connect

    Ganni, Venkatarao; Dixon, Kelly D.; Laverdure, Nathaniel A.; Knudsen, Peter N.; Arenius, Dana M.; Barrios, Matthew N.; Jones, S.; Johnson, M.; Casagrande, Fabio

    2014-01-01

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  9. FRIB cryogenic distribution system

    SciTech Connect

    Ganni, V.; Dixon, K.; Laverdure, N.; Knudsen, P.; Arenius, D.; Barrios, M.; Jones, S.; Johnson, M.; Casagrande, F.

    2014-01-29

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  10. Improved location algorithm for multiple intrusions in distributed Sagnac fiber sensing system.

    PubMed

    Wang, He; Sun, Qizhen; Li, Xiaolei; Wo, Jianghai; Shum, Perry Ping; Liu, Deming

    2014-04-01

    An improved algorithm named "twice-FFT" for multi-point intrusion location in distributed Sagnac sensing system is proposed and demonstrated. To find the null-frequencies more accurately and efficiently, a second FFT is applied to the frequency spectrum of the phase signal caused by intrusion. After Gaussian fitting and searching the peak response frequency in the twice-FFT curve, the intrusion position could be calculated out stably. Meanwhile, the twice-FFT algorithm could solve the problem of multi-point intrusion location. Based on the experiment with twice-FFT algorithm, the location error less than 100m for single intrusion is achieved at any position along the total length of 41km, and the locating ability for two or three intrusions occurring simultaneously is also demonstrated. PMID:24718133

  11. Parametric and nonparametric linkage analysis: A unified multipoint approach

    SciTech Connect

    Kruglyak, L.; Daly, M.J.; Reeve-Daly, M.P.; Lander, E.S.

    1996-06-01

    In complex disease studies, it is crucial to perform multipoint linkage analysis with many markers and to use robust nonparametric methods that take account of all pedigree information. Currently available methods fall short in both regards. In this paper, we describe how to extract complete multipoint inheritance information from general pedigrees of moderate size. This information is captured in the multipoint inheritance distribution, which provides a framework for a unified approach to both parametric and nonparametric methods of linkage analysis. Specifically, the approach includes the following: (1) Rapid exact computation of multipoint LOD scores involving dozens of highly polymorphic markers, even in the presence of loops and missing data. (2) Nonparametric linkage (NPL) analysis, a powerful new approach to pedigree analysis. We show that NPL is robust to uncertainty about mode of inheritance, is much more powerful than commonly used nonparametric methods, and loses little power relative to parametric linkage analysis. NPL thus appears to be the method of choice for pedigree studies of complex traits. (3) Information-content mapping, which measures the fraction of the total inheritance information extracted by the available marker data and points out the regions in which typing additional markers is most useful. (4) Maximum-likelihood reconstruction of many-marker haplotypes, even in pedigrees with missing data. We have implemented NPL analysis, LOD-score computation, information-content mapping, and haplotype reconstruction in a new computer package, GENEHUNTER. The package allows efficient multipoint analysis of pedigree data to be performed rapidly in a single user-friendly environment. 34 refs., 9 figs., 2 tabs.

  12. Smart distribution systems

    DOE PAGES

    Jiang, Yazhou; Liu, Chen -Ching; Xu, Yin

    2016-04-19

    The increasing importance of system reliability and resilience is changing the way distribution systems are planned and operated. To achieve a distribution system self-healing against power outages, emerging technologies and devices, such as remote-controlled switches (RCSs) and smart meters, are being deployed. The higher level of automation is transforming traditional distribution systems into the smart distribution systems (SDSs) of the future. The availability of data and remote control capability in SDSs provides distribution operators with an opportunity to optimize system operation and control. In this paper, the development of SDSs and resulting benefits of enhanced system capabilities are discussed. Amore » comprehensive survey is conducted on the state-of-the-art applications of RCSs and smart meters in SDSs. Specifically, a new method, called Temporal Causal Diagram (TCD), is used to incorporate outage notifications from smart meters for enhanced outage management. To fully utilize the fast operation of RCSs, the spanning tree search algorithm is used to develop service restoration strategies. Optimal placement of RCSs and the resulting enhancement of system reliability are discussed. Distribution system resilience with respect to extreme events is presented. Furthermore, test cases are used to demonstrate the benefit of SDSs. Active management of distributed generators (DGs) is introduced. Future research in a smart distribution environment is proposed.« less

  13. Cooling water distribution system

    DOEpatents

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  14. Distributed generation systems model

    SciTech Connect

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  15. Advanced Distribution Management System

    NASA Astrophysics Data System (ADS)

    Avazov, Artur R.; Sobinova, Liubov A.

    2016-02-01

    This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

  16. Distribution system simulator

    NASA Technical Reports Server (NTRS)

    Bahrami, K. A.; Kirkham, H.; Rahman, S.

    1986-01-01

    In a series of tests performed under the Department of Energy auspices, power line carrier propagation was observed to be anomalous under certain circumstances. To investigate the cause, a distribution system simulator was constructed. The simulator was a physical simulator that accurately represented the distribution system from below power frequency to above 50 kHz. Effects such as phase-to-phase coupling and skin effect were modeled. Construction details of the simulator, and experimental results from its use are presented.

  17. ENLIL Global Heliospheric Modeling as a Context For Multipoint Observations

    NASA Astrophysics Data System (ADS)

    Mays, M. Leila; Odstrcil, Dusan; Luhmann, Janet; Bain, Hazel; Li, Yan; Schwadron, Nathan; Gorby, Matt; Thompson, Barbara; Jian, Lan; Möstl, Christian; Rouillard, Alexis; Davies, Jackie; Temmer, Manuela; Rastaetter, Lutz; Taktakishvili, Aleksandre; MacNeice, Peter; Kuznetsova, Maria

    2016-04-01

    We present heliospheric simulation case studies using recent enhancements to WSA--ENLIL+Cone (version 2.8) at the Community Coordinated Modeling Center (CCMC). The global 3D MHD ENLIL model provides a time-dependent description of the background solar wind plasma and magnetic field using a sequence of WSA coronal model maps as input at the inner boundary of 21.5 Rs. A homogeneous, over-pressured hydrodynamic plasma cloud is launched through the inner boundary of the heliospheric computational domain and into the background solar wind. Multipoint observations help constrain simulations and this modeling system provides global context and arrival times of the solar wind streams and CMEs at Earth, planets, and spacecraft. Additionally, one can extract the magnetic topologies of observer-connected magnetic field lines and all plasma and shock properties along those field lines. ENLIL "likelihood/all-clear" forecasting maps provide expected intensity, timing/duration of events at locations throughout the heliosphere with "possible SEP affected areas" color-coded based on shock strength. ENLIL simulations are also useful to drive SEP models such as the Solar Energetic Particle Model (SEPMOD) (Luhmann et al. 2007, 2010) and Energetic Particle Radiation Environment Module (EPREM) (Schwadron et al., 2010). SEPMOD injects protons onto a sequence observer field lines at intensities dependent on the connected shock source strength which are then integrated at the observer to approximate the proton flux. EPREM couples with MHD models such as ENLIL and computes energetic particle distributions based on the focused transport equation along a Lagrangian grid of nodes that propagate out with the solar wind. Studies have shown that accurate descriptions of the heliosphere, and hence modeled CME arrival times and SEPs, are achieved by ENLIL only when the background solar wind is well-reproduced and CME parameters are accurate. It is essential to include all of the relevant CMEs and

  18. Multipoint study of interplanetary shocks

    NASA Astrophysics Data System (ADS)

    Blanco-Cano, Xochitl; Kajdic, Primoz; Russell, Christopher T.; Aguilar-Rodriguez, Ernesto; Jian, Lan K.; Luhmann, Janet G.

    2016-04-01

    Interplanetary (IP) shocks are driven in the heliosphere by Interplanetary Coronal Mass Ejections (ICMEs) and Stream Interaction Regions (SIRs). These shocks perturb the solar wind plasma, and play an active role in the acceleration of ions to suprathermal energies. Shock fronts evolve as they move from the Sun. Their surfaces can be far from uniform and be modulated by changes in the ambient solar wind (magnetic field orientation, flow velocity), shocks rippling, and perturbations upstream and downstream from the shocks, i.e., electromagnetic waves. In this work we use multipoint observations from STEREO, WIND, and MESSENGER missions to study shock characteristics at different helio-longitudes and determine the properties of the waves near them. We also determine shock longitudinal extensions and foreshock sizes. The variations of geometry along the shock surface can result in different extensions of the wave and ion foreshocks ahead of the shocks, and in different wave modes upstream and downtream of the shocks. We find that the ion foreshock can extend up to 0.2 AU ahead of the shock, and that the upstream region with modified solar wind/waves can be very asymmetric.

  19. Integrated Multipoint-Laser Endoscopic Airway Measurements by Transoral Approach

    PubMed Central

    Neitsch, Marie; Horn, Iris-Susanne; Hofer, Mathias; Dietz, Andreas; Fischer, Miloš

    2016-01-01

    Objectives. Optical and technical characteristics usually do not allow objective endoscopic distance measurements. So far no standardized method for endoscopic distance measurement is available. The aim of this study was to evaluate the feasibility and accuracy of transoral airway measurements with a multipoint-laser endoscope. Methods. The semirigid endoscope includes a multipoint laser measurement system that projects 49 laser points (wavelength 639 nm, power < 5 mW) into the optical axis of the endoscopic view. Distances, areas, and depths can be measured in real-time. Transoral endoscopic airway measurements were performed on nine human cadavers, which were correlated with CT measurements. Results. The preliminary experiment showed an optimum distance between the endoscope tip and the object of 5 to 6 cm. There was a mean measurement error of 3.26% ± 2.53%. A Spearman correlation coefficient of 0.95 (p = 0.01) was calculated for the laryngeal measurements and of 0.93 (p < 0.01) for the tracheal measurements compared to the CT. Using the Bland-Altman-Plot, the 95% limits of agreement for the laryngeal measurements were satisfactory: −0.76 and 0.93. Conclusions. Integrated multipoint-laser endoscopic measurement is a promising technical supplement, with potential use in diagnostic endoscopy and transoral endoscopic surgery in daily practice. PMID:27022612

  20. A new system for the analysis of thermal judgments: multipoint measurements of skin temperatures and temperature-related sensations and their joint visualization.

    PubMed

    Nakamura, Mayumi; Esaki, Hidenori; Yoda, Tamae; Yasuhara, Saki; Kobayashi, Akiko; Konishi, Aki; Osawa, Naoki; Nagashima, Kei; Crawshaw, Larry I; Kanosue, Kazuyuki

    2006-12-01

    We report a new system for monitoring sensations of many body parts as well as comprehensively showing the distribution of overall skin temperature (T(sk)) and temperature-related sensations. The system consists of a console with 52 levers to report temperature-related sensations and software that facilitates the visualization of the distribution of T(sk) and temperature-related sensations by displaying them on a model of the human body. The system's utility was demonstrated with a physiological experiment involving three males and three females. They were exposed to step changes of ambient temperature from 23 degrees C to 33 degrees C. We measured T(sk) at 50 points, and the subjects concurrently provided estimates of local temperature sensation and thermal comfort/discomfort at 25 loci. This system greatly facilitates the perception and analysis of spatial relationships and differences in temperature and sensation in various areas of the body.

  1. Distributed Optimization System

    DOEpatents

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2004-11-30

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  2. Distributed Data Management and Distributed File Systems

    NASA Astrophysics Data System (ADS)

    Girone, Maria

    2015-12-01

    The LHC program has been successful in part due to the globally distributed computing resources used for collecting, serving, processing, and analyzing the large LHC datasets. The introduction of distributed computing early in the LHC program spawned the development of new technologies and techniques to synchronize information and data between physically separated computing centers. Two of the most challenges services are the distributed file systems and the distributed data management systems. In this paper I will discuss how we have evolved from local site services to more globally independent services in the areas of distributed file systems and data management and how these capabilities may continue to evolve into the future. I will address the design choices, the motivations, and the future evolution of the computing systems used for High Energy Physics.

  3. Distributed Deliberative Recommender Systems

    NASA Astrophysics Data System (ADS)

    Recio-García, Juan A.; Díaz-Agudo, Belén; González-Sanz, Sergio; Sanchez, Lara Quijano

    Case-Based Reasoning (CBR) is one of most successful applied AI technologies of recent years. Although many CBR systems reason locally on a previous experience base to solve new problems, in this paper we focus on distributed retrieval processes working on a network of collaborating CBR systems. In such systems, each node in a network of CBR agents collaborates, arguments and counterarguments its local results with other nodes to improve the performance of the system's global response. We describe D2ISCO: a framework to design and implement deliberative and collaborative CBR systems that is integrated as a part of jcolibritwo an established framework in the CBR community. We apply D2ISCO to one particular simplified type of CBR systems: recommender systems. We perform a first case study for a collaborative music recommender system and present the results of an experiment of the accuracy of the system results using a fuzzy version of the argumentation system AMAL and a network topology based on a social network. Besides individual recommendation we also discuss how D2ISCO can be used to improve recommendations to groups and we present a second case of study based on the movie recommendation domain with heterogeneous groups according to the group personality composition and a group topology based on a social network.

  4. Distributed computing systems programme

    SciTech Connect

    Duce, D.

    1984-01-01

    Publication of this volume coincides with the completion of the U.K. Science and Engineering Research Council's coordinated programme of research in Distributed Computing Systems (DCS) which ran from 1977 to 1984. The volume is based on presentations made at the programme's final conference. The first chapter explains the origins and history of DCS and gives an overview of the programme and its achievements. The remaining sixteen chapters review particular research themes (including imperative and declarative languages, and performance modelling), and describe particular research projects in technical areas including local area networks, design, development and analysis of concurrent systems, parallel algorithm design, functional programming and non-von Neumann computer architectures.

  5. Distributed System Design Checklist

    NASA Technical Reports Server (NTRS)

    Hall, Brendan; Driscoll, Kevin

    2014-01-01

    This report describes a design checklist targeted to fault-tolerant distributed electronic systems. Many of the questions and discussions in this checklist may be generally applicable to the development of any safety-critical system. However, the primary focus of this report covers the issues relating to distributed electronic system design. The questions that comprise this design checklist were created with the intent to stimulate system designers' thought processes in a way that hopefully helps them to establish a broader perspective from which they can assess the system's dependability and fault-tolerance mechanisms. While best effort was expended to make this checklist as comprehensive as possible, it is not (and cannot be) complete. Instead, we expect that this list of questions and the associated rationale for the questions will continue to evolve as lessons are learned and further knowledge is established. In this regard, it is our intent to post the questions of this checklist on a suitable public web-forum, such as the NASA DASHLink AFCS repository. From there, we hope that it can be updated, extended, and maintained after our initial research has been completed.

  6. Distributed fuzzy system modeling

    SciTech Connect

    Pedrycz, W.; Chi Fung Lam, P.; Rocha, A.F.

    1995-05-01

    The paper introduces and studies an idea of distributed modeling treating it as a new paradigm of fuzzy system modeling and analysis. This form of modeling is oriented towards developing individual (local) fuzzy models for specific modeling landmarks (expressed as fuzzy sets) and determining the essential logical relationships between these local models. The models themselves are implemented in the form of logic processors being regarded as specialized fuzzy neural networks. The interaction between the processors is developed either in an inhibitory or excitatory way. In more descriptive way, the distributed model can be sought as a collection of fuzzy finite state machines with their individual local first or higher order memories. It is also clarified how the concept of distributed modeling narrows down a gap between purely numerical (quantitative) models and the qualitative ones originated within the realm of Artificial Intelligence. The overall architecture of distributed modeling is discussed along with the detailed learning schemes. The results of extensive simulation experiments are provided as well. 17 refs.

  7. Planning Systems for Distributed Operations

    NASA Technical Reports Server (NTRS)

    Maxwell, Theresa G.

    2002-01-01

    This viewgraph representation presents an overview of the mission planning process involving distributed operations (such as the International Space Station (ISS)) and the computer hardware and software systems needed to support such an effort. Topics considered include: evolution of distributed planning systems, ISS distributed planning, the Payload Planning System (PPS), future developments in distributed planning systems, Request Oriented Scheduling Engine (ROSE) and Next Generation distributed planning systems.

  8. Factors affecting distributed system security

    SciTech Connect

    Nessett, D.M.

    1985-11-13

    Recent work examining distributed system security requirements is critiqued. A notion of trust based on distributed system topology and distributed system node evaluation levels proposed in that work is shown to be deficient. The notion fails to make allowances for the distributed system physical security environment, security factors related to the management of distributed systems by more than one jurisdictive authority and interactions that can occur between nodes supporting different mandatory and discretionary security mechanisms.

  9. Automated Gas Distribution System

    NASA Astrophysics Data System (ADS)

    Starke, Allen; Clark, Henry

    2012-10-01

    The cyclotron of Texas A&M University is one of the few and prized cyclotrons in the country. Behind the scenes of the cyclotron is a confusing, and dangerous setup of the ion sources that supplies the cyclotron with particles for acceleration. To use this machine there is a time consuming, and even wasteful step by step process of switching gases, purging, and other important features that must be done manually to keep the system functioning properly, while also trying to maintain the safety of the working environment. Developing a new gas distribution system to the ion source prevents many of the problems generated by the older manually setup process. This developed system can be controlled manually in an easier fashion than before, but like most of the technology and machines in the cyclotron now, is mainly operated based on software programming developed through graphical coding environment Labview. The automated gas distribution system provides multi-ports for a selection of different gases to decrease the amount of gas wasted through switching gases, and a port for the vacuum to decrease the amount of time spent purging the manifold. The Labview software makes the operation of the cyclotron and ion sources easier, and safer for anyone to use.

  10. Distributed road assessment system

    DOEpatents

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

    A system that detects damage on or below the surface of a paved structure or pavement is provided. A distributed road assessment system includes road assessment pods and a road assessment server. Each road assessment pod includes a ground-penetrating radar antenna array and a detection system that detects road damage from the return signals as the vehicle on which the pod is mounted travels down a road. Each road assessment pod transmits to the road assessment server occurrence information describing each occurrence of road damage that is newly detected on a current scan of a road. The road assessment server maintains a road damage database of occurrence information describing the previously detected occurrences of road damage. After the road assessment server receives occurrence information for newly detected occurrences of road damage for a portion of a road, the road assessment server determines which newly detected occurrences correspond to which previously detected occurrences of road damage.

  11. Quality monitored distributed voting system

    DOEpatents

    Skogmo, David

    1997-01-01

    A quality monitoring system can detect certain system faults and fraud attempts in a distributed voting system. The system uses decoy voters to cast predetermined check ballots. Absent check ballots can indicate system faults. Altered check ballots can indicate attempts at counterfeiting votes. The system can also cast check ballots at predetermined times to provide another check on the distributed voting system.

  12. Quality monitored distributed voting system

    DOEpatents

    Skogmo, D.

    1997-03-18

    A quality monitoring system can detect certain system faults and fraud attempts in a distributed voting system. The system uses decoy voters to cast predetermined check ballots. Absent check ballots can indicate system faults. Altered check ballots can indicate attempts at counterfeiting votes. The system can also cast check ballots at predetermined times to provide another check on the distributed voting system. 6 figs.

  13. Process evaluation distributed system

    NASA Technical Reports Server (NTRS)

    Moffatt, Christopher L. (Inventor)

    2006-01-01

    The distributed system includes a database server, an administration module, a process evaluation module, and a data display module. The administration module is in communication with the database server for providing observation criteria information to the database server. The process evaluation module is in communication with the database server for obtaining the observation criteria information from the database server and collecting process data based on the observation criteria information. The process evaluation module utilizes a personal digital assistant (PDA). A data display module in communication with the database server, including a website for viewing collected process data in a desired metrics form, the data display module also for providing desired editing and modification of the collected process data. The connectivity established by the database server to the administration module, the process evaluation module, and the data display module, minimizes the requirement for manual input of the collected process data.

  14. The Saguaro distributed operating system

    NASA Astrophysics Data System (ADS)

    Andrews, Gregory R.; Schlichting, Richard D.

    1989-05-01

    The progress achieved over the final year of the Saguaro distributed operating system project is presented. The primary achievements were in related research, including SR distributed programming language, the MLP system for constructing distributed mixed-language programs, the Psync interprocess communication mechanism, a configurable operating system kernal called the x-kernal, and the development of language mechanisms for performing failure handling in distributed programming languages.

  15. Flow Distribution in Hydraulic Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, S. N.

    1983-01-01

    General Flow Distribution Program analyzes pressure drops and flow distribution in closed and open hydraulic systems. Analyzes system on basis of incompressible flow though system may contain either compressible or incompressible fluid. Program solves fixed or variable flow problems for series, parallel, or series/parallel systems.

  16. ANN - based distribution system reconfiguration

    SciTech Connect

    Momoh, J.A.; Wang, Yanchun; Rizy, D.T.

    1997-08-01

    This paper describes an Artificial Neural Network (ANN) - based distribution system reconfiguration scheme to reduce system loss. The ANN is trained for different load levels and different network topologies. The proposed scheme has been tested using a 38 - bus distribution system. The results are very promising.

  17. Distributed systems status and control

    NASA Technical Reports Server (NTRS)

    Kreidler, David; Vickers, David

    1990-01-01

    Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

  18. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Thomason, Cindy; Anderson, Paul M.; Martin, James A.

    1990-01-01

    Automated power-distribution system monitors and controls electrical power to modules in network. Handles both 208-V, 20-kHz single-phase alternating current and 120- to 150-V direct current. Power distributed to load modules from power-distribution control units (PDCU's) via subsystem distributors. Ring busses carry power to PDCU's from power source. Needs minimal attention. Detects faults and also protects against them. Potential applications include autonomous land vehicles and automated industrial process systems.

  19. Water Treatment Technology - Distribution Systems.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on distribution systems provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pipe for distribution systems, types…

  20. Exploiting replication in distributed systems

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Joseph, T. A.

    1989-01-01

    Techniques are examined for replicating data and execution in directly distributed systems: systems in which multiple processes interact directly with one another while continuously respecting constraints on their joint behavior. Directly distributed systems are often required to solve difficult problems, ranging from management of replicated data to dynamic reconfiguration in response to failures. It is shown that these problems reduce to more primitive, order-based consistency problems, which can be solved using primitives such as the reliable broadcast protocols. Moreover, given a system that implements reliable broadcast primitives, a flexible set of high-level tools can be provided for building a wide variety of directly distributed application programs.

  1. MULTI-POINT RADIATION MONITOR

    SciTech Connect

    Hofstetter, K; Donna Beals, D; Ken Odell, K; Robert Eakle, R; Russell Huffman, R; Larry Harpring, L

    2006-05-12

    A unique radiation monitor has been developed for performing wide-area field surveys for radiation sources. This device integrates the real-time output of multiple radiation detectors into a hand-held personal computer (e.g., a PDA) containing an intuitive graphical user interface. An independent hardware module supplies high voltage to the detectors and contains a rapid sampling system for transferring the detector count rates through an interface to the PDA. The imbedded firmware can be changed for various applications using a programmable memory card. As presently configured, the instrument contains a series of Geiger-Mueller (GM) tubes in a flexible detector string. This linear array of multiple sensors can be used by US Coast Guard and Customs container inspection personnel to measure radiation intensity in stacks of transport containers where physical access is impeded.

  2. Two-wavelength quadrature multipoint detection of partial discharge in power transformers using fiber Fabry-Perot acoustic sensors

    NASA Astrophysics Data System (ADS)

    Dong, Bo; Han, Ming; Wang, Anbo

    2012-06-01

    A reliable and low-cost two-wavelength quadrature interrogating method has been developed to demodulate optical signals from diaphragm-based Fabry-Perot interferometric fiber optic sensors for multipoint partial discharge detection in power transformers. Commercial available fused-silica parts (a wafer, a fiber ferrule, and a mating sleeve) and a cleaved optical single mode fiber were bonded together to form an extrinsic Fabry-Perot acoustic sensor. Two lasers with center wavelengths separated by a quarter of the period of sensor interference fringes were used to probe acousticwave- induced diaphragm vibration. A coarse wavelength-division multiplexing (CWDM) add/drop multiplexer was used to separate the reflected two wavelengths before two photo detectors. Optical couplers were used to distribute mixed laser light to each sensor-detector module for multiplexing purpose. Sensor structure, detection system design and experiment results are presented.

  3. The use of multipoint monitoring as a tool for commissioning buildings for IAQ

    SciTech Connect

    Bearg, D.W.

    1999-07-01

    One basic goal of the commissioning process is to make sure that the HVAC system is functioning as intended. In particular, it is intended that the HVAC system not only provide adequate ventilation for the building occupants but also achieve adequate pressurization of the occupied spaces to prevent the infiltration of unconditioned air. One technique for evaluating the performance of the HVAC system in these areas is to use continual, multipoint monitoring of carbon dioxide, carbon monoxide, and dew point at selected locations in the building and the HVAC system. Specific examples of all of these performance evaluations are presented and discussed in this paper. In addition, these ongoing evaluations of system performance can not only identify the presence of problems but can also evaluate the effectiveness of mitigation efforts to correct and eliminate these problems. The use of continual, multipoint monitoring of these parameters, therefore, can yield improved indoor air quality (IAQ) in buildings from initial occupancy throughout their useful life.

  4. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Ashworth, Barry; Riedesel, Joel; Myers, Chris; Miller, William; Jones, Ellen F.; Freeman, Kenneth; Walsh, Richard; Walls, Bryan K.; Weeks, David J.; Bechtel, Robert T.

    1992-01-01

    Autonomous power-distribution system includes power-control equipment and automation equipment. System automatically schedules connection of power to loads and reconfigures itself when it detects fault. Potential terrestrial applications include optimization of consumption of power in homes, power supplies for autonomous land vehicles and vessels, and power supplies for automated industrial processes.

  5. Distribution System of the Future

    SciTech Connect

    Kueck, JD

    2003-04-23

    The distribution system of the future is going to be as much of a revolution to the electric energy industry as the wireless telephone has been to consumer communications. An electricity market transformation must occur before the changes can take place, but this evolution is already starting to occur in many parts of the country. In this paper, we discuss a vision for a future distribution system, areas that will be key for technology development, and the advantages of the new electricity market. Present day distribution systems are in a sense, unintelligent. Distribution systems respond to faults, or short circuits, by sensing the very high fault current and then opening circuit breakers to isolate the fault. Some newer automated systems determine fault location and then close other circuit breakers to provide an alternate path for power after the fault so that the number of customers left without power is minimized, but the extent of the reconfiguration is limited. Distribution systems also have some methods to regulate voltage, but there is little real time local response to contingencies such as loss of a transmission line or a generator. In present day distribution systems, there is very little control of load, or demand response, and Distributed Energy Resources (DER, distributed generation, storage, and responsive load) located in the distribution system are prohibited from even regulating voltage. In fact, industry standards and utility interconnection agreements typically require that when a contingency occurs on a distribution or transmission system that results in a voltage or frequency excursion, the DER is to disconnect rather than help. There is a pressing need to evolve the distribution system model to one that can respond to contingencies sensed locally, and has the local intelligence and autonomy to deal with contingencies such as unusual loading, transmission congestion, and line outages. Markets must be simple for customers to participate in the

  6. How robust are distributed systems

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1989-01-01

    A distributed system is made up of large numbers of components operating asynchronously from one another and hence with imcomplete and inaccurate views of one another's state. Load fluctuations are common as new tasks arrive and active tasks terminate. Jointly, these aspects make it nearly impossible to arrive at detailed predictions for a system's behavior. It is important to the successful use of distributed systems in situations in which humans cannot provide the sorts of predictable realtime responsiveness of a computer, that the system be robust. The technology of today can too easily be affected by worn programs or by seemingly trivial mechanisms that, for example, can trigger stock market disasters. Inventors of a technology have an obligation to overcome flaws that can exact a human cost. A set of principles for guiding solutions to distributed computing problems is presented.

  7. Maintaining consistency in distributed systems

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1991-01-01

    In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability.

  8. Space Technology 5 Multi-Point Field-Aligned Current Measurements (Invited)

    NASA Astrophysics Data System (ADS)

    Slavin, J. A.; Le, G.; Gjerloev, J. W.

    2013-12-01

    NASA's Space Technology 5 (ST 5) microsatellite constellation technology mission was launched by a Pegasus launch vehicle on March 22, 2006. The three small (48 cm tall, 50 cm diameter, 25 kg mass, spin stabilized at 20 rpm) satellites were placid in a 300 x 4500 km, dawn to dusk, sun synchronous orbit (inclination = 105.6 deg) orbit with a period of 138 min. They were maintained in this 'pearls on a sting' formation with inter-satellite spacings ranging from over 5000 km to under 50 km. Each satellite carried a miniature tri-axial fluxgate magnetometer (MAG) provided by the University of California at Los Angeles. Field aligned currents (FACs) form in response to the stress exerted on the magnetosphere by the solar wind and act as the primary mechanism for dissipating solar wind energy into the ionosphere and upper atmosphere during the solar wind magnetosphere ionosphere coupling process. ST 5 returned the first direct, simultaneous, multipoint measurements of FAC motion, thickness, and temporal variability. Current density was measured using both 1) the 'standard method' based upon s/c velocity, but corrected for FAC current sheet motion, with the assumption of a time-stationary current density profile, and 2) for the first time at low altitudes, the 'gradiometer method' which uses simultaneous magnetic field measurements at two points with known separation. Here we review the ST 5 scientific results concerning FACs and discuss their implications for future investigations of field aligned currents systems using distributed systems of spaceborne magnetometers.

  9. Distributed Virtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1993-01-01

    As outlined in the continuation proposal 92-ISI-50R (revised) on NASA cooperative agreement NCC 2-539, the investigators are developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to develop and execute parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; developing communications routines that support the abstractions implemented; continuing the development of file and information systems based on the Virtual System Model; and incorporating appropriate security measures to allow the mechanisms developed to be used on an open network. The goal throughout the work is to provide a uniform model that can be applied to both parallel and distributed systems. The authors believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. The work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  10. Distributed Virtual System (DIVIRS) Project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1993-01-01

    As outlined in our continuation proposal 92-ISI-50R (revised) on contract NCC 2-539, we are (1) developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to program parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; (2) developing communications routines that support the abstractions implemented in item one; (3) continuing the development of file and information systems based on the virtual system model; and (4) incorporating appropriate security measures to allow the mechanisms developed in items 1 through 3 to be used on an open network. The goal throughout our work is to provide a uniform model that can be applied to both parallel and distributed systems. We believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. Our work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  11. DIstributed VIRtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, Clifford B.

    1995-01-01

    As outlined in our continuation proposal 92-ISI-50R (revised) on NASA cooperative agreement NCC2-539, we are (1) developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to develop and execute parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; (2) developing communications routines that support the abstractions implemented in item one; (3) continuing the development of file and information systems based on the Virtual System Model; and (4) incorporating appropriate security measures to allow the mechanisms developed in items 1 through 3 to be used on an open network. The goal throughout our work is to provide a uniform model that can be applied to both parallel and distributed systems. We believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. Our work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  12. DIstributed VIRtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1994-01-01

    As outlined in our continuation proposal 92-ISI-. OR (revised) on NASA cooperative agreement NCC2-539, we are (1) developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to develop and execute parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; (2) developing communications routines that support the abstractions implemented in item one; (3) continuing the development of file and information systems based on the Virtual System Model; and (4) incorporating appropriate security measures to allow the mechanisms developed in items 1 through 3 to be used on an open network. The goal throughout our work is to provide a uniform model that can be applied to both parallel and distributed systems. We believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. Our work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  13. Enhanced distributed energy resource system

    DOEpatents

    Atcitty, Stanley; Clark, Nancy H.; Boyes, John D.; Ranade, Satishkumar J.

    2007-07-03

    A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

  14. Properly Understanding the Impacts of Distributed Resources on Distribution Systems

    SciTech Connect

    Rizy, D Tom; Li, Fangxing; Li, Huijuan; Adhikari, Sarina; Kueck, John D

    2010-01-01

    The subject paper discusses important impacts of distributed resources on distribution networks and feeders. These include capacity, line losses, voltage regulation, and central system support (such as volt/var via central generators and substation) as the number, placement and penetration levels of distributed resources are varied. Typically, the impacts of distributed resources on the distribution system are studied by using steady-state rather than dynamic analysis tools. However, the response time and transient impacts of both system equipment (such as substation/feeder capacitors) and distributed resources needs to be taken into account and only dynamic analysis will provide the full impact results. ORNL is wrapping up a study of distributed resources interconnected to a large distribution system considering the above variables. A report of the study and its results will be condensed into a paper for this panel session. The impact of distributed resources will vary as the penetration level reaches the capacity of the distribution feeder/system. The question is how high of a penetration of distributed resource can be accommodated on the distribution feeder/system without any major changes to system operation, design and protection. The impacts most surely will vary depending upon load composition, distribution and level. Also, it is expected that various placement of distributed resources will impact the distribution system differently.

  15. Role of the Symmetry of Multipoint Hydrogen Bonding on Chelate Cooperativity in Supramolecular Macrocyclization Processes.

    PubMed

    Montoro-García, Carlos; Camacho-García, Jorge; López-Pérez, Ana M; Mayoral, María J; Bilbao, Nerea; González-Rodríguez, David

    2016-01-01

    Herein, we analyze the intrinsic chelate effect that multipoint H-bonding patterns exert on the overall energy of dinucleoside cyclic systems. Our results indicate that the chelate effect is regulated by the symmetry of the H-bonding pattern, and that the effective molarity is reduced by about three orders of magnitude when going from the unsymmetric ADD-DAA or DDA-AAD patterns to the symmetric DAD-ADA pattern.

  16. Distributed optimization system and method

    DOEpatents

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2003-06-10

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  17. World-wide distribution automation systems

    SciTech Connect

    Devaney, T.M.

    1994-12-31

    A worldwide power distribution automation system is outlined. Distribution automation is defined and the status of utility automation is discussed. Other topics discussed include a distribution management system, substation feeder, and customer functions, potential benefits, automation costs, planning and engineering considerations, automation trends, databases, system operation, computer modeling of system, and distribution management systems.

  18. MLAOS: A Multi-Point Linear Array of Optical Sensors for Coniferous Foliage Clumping Index Measurement

    PubMed Central

    Qu, Yonghua; Fu, Lizhe; Han, Wenchao; Zhu, Yeqing; Wang, Jindi

    2014-01-01

    The canopy foliage clumping effect is primarily caused by the non-random distribution of canopy foliage. Currently, measurements of clumping index (CI) by handheld instruments is typically time- and labor-intensive. We propose a low-cost and low-power automatic measurement system called Multi-point Linear Array of Optical Sensors (MLAOS), which consists of three above-canopy and nine below-canopy optical sensors that capture plant transmittance at different times of the day. Data communication between the MLAOS node is facilitated by using a ZigBee network, and the data are transmitted from the field MLAOS to a remote data server using the Internet. The choice of the electronic element and design of the MLAOS software is aimed at reducing costs and power consumption. A power consumption test showed that, when a 4000 mAH Li-ion battery is used, a maximum of 8–10 months of work can be achieved. A field experiment on a coniferous forest revealed that the CI of MLAOS may reveal a clumping effect that occurs within the canopy. In further work, measurement of the multi-scale clumping effect can be achieved by utilizing a greater number of MLAOS devices to capture the heterogeneity of the plant canopy. PMID:24859029

  19. Hazards Data Distribution System (HDDS)

    USGS Publications Warehouse

    Jones, Brenda; Lamb, Rynn M.

    2015-07-09

    When emergencies occur, first responders and disaster response teams often need rapid access to aerial photography and satellite imagery that is acquired before and after the event. The U.S. Geological Survey (USGS) Hazards Data Distribution System (HDDS) provides quick and easy access to pre- and post-event imagery and geospatial datasets that support emergency response and recovery operations. The HDDS provides a single, consolidated point-of-entry and distribution system for USGS-hosted remotely sensed imagery and other geospatial datasets related to an event response. The data delivery services are provided through an interactive map-based interface that allows emergency response personnel to rapidly select and download pre-event ("baseline") and post-event emergency response imagery.

  20. The data distribution satellite system

    NASA Technical Reports Server (NTRS)

    Bruno, Ronald C.; Weinberg, Aaron

    1991-01-01

    The Data Distributed Satellite (DDS) will be capable of providing the space research community with inexpensive and easy access to space payloads and space data. Furthermore, the DDS is shown to be a natural outgrowth of advances and evolution in both NASA's Space Network and commercial satellite communications. The roadmap and timescale for this evolution is described along with key demonstrations, proof-of-concept models, and required technology development that will support the projected system evolution toward the DDS.

  1. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Electrical Systems and Equipment § 25.1355 Distribution system. (a) The distribution system includes the distribution busses, their associated feeders... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Distribution system. 25.1355 Section...

  2. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Electrical Systems and Equipment § 29.1355 Distribution system. (a) The distribution system includes the distribution busses, their associated feeders... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Distribution system. 29.1355 Section...

  3. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Electrical Systems and Equipment § 29.1355 Distribution system. (a) The distribution system includes the distribution busses, their associated feeders... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Distribution system. 29.1355 Section...

  4. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Electrical Systems and Equipment § 25.1355 Distribution system. (a) The distribution system includes the distribution busses, their associated feeders... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Distribution system. 25.1355 Section...

  5. Reliable Wireless Broadcast with Linear Network Coding for Multipoint-to-Multipoint Real-Time Communications

    NASA Astrophysics Data System (ADS)

    Kondo, Yoshihisa; Yomo, Hiroyuki; Yamaguchi, Shinji; Davis, Peter; Miura, Ryu; Obana, Sadao; Sampei, Seiichi

    This paper proposes multipoint-to-multipoint (MPtoMP) real-time broadcast transmission using network coding for ad-hoc networks like video game networks. We aim to achieve highly reliable MPtoMP broadcasting using IEEE 802.11 media access control (MAC) that does not include a retransmission mechanism. When each node detects packets from the other nodes in a sequence, the correctly detected packets are network-encoded, and the encoded packet is broadcasted in the next sequence as a piggy-back for its native packet. To prevent increase of overhead in each packet due to piggy-back packet transmission, network coding vector for each node is exchanged between all nodes in the negotiation phase. Each user keeps using the same coding vector generated in the negotiation phase, and only coding information that represents which user signal is included in the network coding process is transmitted along with the piggy-back packet. Our simulation results show that the proposed method can provide higher reliability than other schemes using multi point relay (MPR) or redundant transmissions such as forward error correction (FEC). We also implement the proposed method in a wireless testbed, and show that the proposed method achieves high reliability in a real-world environment with a practical degree of complexity when installed on current wireless devices.

  6. Probability distributions for multimeric systems.

    PubMed

    Albert, Jaroslav; Rooman, Marianne

    2016-01-01

    We propose a fast and accurate method of obtaining the equilibrium mono-modal joint probability distributions for multimeric systems. The method necessitates only two assumptions: the copy number of all species of molecule may be treated as continuous; and, the probability density functions (pdf) are well-approximated by multivariate skew normal distributions (MSND). Starting from the master equation, we convert the problem into a set of equations for the statistical moments which are then expressed in terms of the parameters intrinsic to the MSND. Using an optimization package on Mathematica, we minimize a Euclidian distance function comprising of a sum of the squared difference between the left and the right hand sides of these equations. Comparison of results obtained via our method with those rendered by the Gillespie algorithm demonstrates our method to be highly accurate as well as efficient.

  7. Distributed antenna system and method

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W. (Inventor); Dobbins, Justin A. (Inventor)

    2004-01-01

    System and methods are disclosed for employing one or more radiators having non-unique phase centers mounted to a body with respect to a plurality of transmitters to determine location characteristics of the body such as the position and/or attitude of the body. The one or more radiators may consist of a single, continuous element or of two or more discrete radiation elements whose received signals are combined. In a preferred embodiment, the location characteristics are determined using carrier phase measurements whereby phase center information may be determined or estimated. A distributed antenna having a wide angle view may be mounted to a moveable body in accord with the present invention. The distributed antenna may be utilized for maintaining signal contact with multiple spaced apart transmitters, such as a GPS constellation, as the body rotates without the need for RF switches to thereby provide continuous attitude and position determination of the body.

  8. 47 CFR 101.1009 - System operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may...

  9. 47 CFR 101.1009 - System operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may...

  10. 47 CFR 101.1009 - System operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may...

  11. 47 CFR 101.1009 - System operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may...

  12. 47 CFR 101.1009 - System operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may...

  13. Multipoint Thomson scattering diagnostic for DIII-D

    NASA Astrophysics Data System (ADS)

    Hsieh, C. L.; Chase, R.; Deboo, J. C.; Evanko, R. G.; Gohil, P.; Snider, R. T.; Stockdale, R. E.

    1988-02-01

    The multipoint Thomson scattering diagnostic for DIII-D has been in operation since early 1987. Its capability of measuring electron temperatures as low as 50 eV at densities of a few times 10 to the 12th/cu cm and a spatial resolution of 1.4 cm in the plasma edge region has been essential in the study of H-mode plasmas. The major components of the diagnositic system consist of a 10-J ruby laser, many stages of funnel shaped beam baffles, stacks of razor blades for viewing and stray light dumps, two wide-angle lenses for the collection of scattered light through re-entrant window ports with protection shutters, 88 fiber bundles 15 m in length for light transmission to an focal length/1.9 spectrometer, an intensified CCD camera system capable of single photon detection, and a VAX computer for hardware control and data processing. The input end of the fiber bundle is made demountable so the view locations can be reconfigured to optimize the spatial resolution for the plasma region of interest.

  14. Multipoint Thomson scattering diagnostic for DIII-D

    NASA Astrophysics Data System (ADS)

    Hsieh, C. L.; Chase, R.; DeBoo, J. C.; Evanko, R. G.; Gohil, P.; Snider, R. T.; Stockdale, R. E.

    1988-08-01

    The multipoint Thomson scattering diagnostic for DIII-D has been in operation since early 1987. Its capability of measuring electron temperatures as low as 50 eV at densities of a few times 1012 cm-3 and a spatial resolution of 1.4 cm in the plasma edge region has been essential in the study of H-mode plasmas. The major components of the diagnostic system consist of a 10-J ruby laser, many stages of funnel-shaped beam baffles, stacks of razor blades for viewing and stray light dumps, two wide-angle lenses for the collection of scattered light through reentrant window ports with protection shutters, 88 fiber bundles 15 m in length for light transmission to an f/1.9 spectrometer, an intensified CCD camera system capable of single-photon detection, and a VAX computer for hardware control and data processing. The input end of the fiber bundle is made demountable so the view locations can be reconfigured to optimize the spatial resolution for the plasma region of interest.

  15. Video distribution system cost model

    NASA Technical Reports Server (NTRS)

    Gershkoff, I.; Haspert, J. K.; Morgenstern, B.

    1980-01-01

    A cost model that can be used to systematically identify the costs of procuring and operating satellite linked communications systems is described. The user defines a network configuration by specifying the location of each participating site, the interconnection requirements, and the transmission paths available for the uplink (studio to satellite), downlink (satellite to audience), and voice talkback (between audience and studio) segments of the network. The model uses this information to calculate the least expensive signal distribution path for each participating site. Cost estimates are broken downy by capital, installation, lease, operations and maintenance. The design of the model permits flexibility in specifying network and cost structure.

  16. Duplex Direct Data Distribution System

    NASA Technical Reports Server (NTRS)

    Greenfield, Israel (Technical Monitor)

    2001-01-01

    The NASA Glenn Research Center (GRC) is developing and demonstrating communications and network technologies that are helping to enable the near-Earth space Internet. GRC envisions several service categories. The first of these categories is direct data distribution or D3 (pronounced "D-cubed"). Commercially provided D3 will make it possible to download a data set from a spacecraft, like the International Space Station. as easily as one can extract a file from a remote server today, using a file transfer protocol. In a second category, NASA spacecraft will make use of commercial satellite communication (SATCOM) systems. Some of those services will come from purchasing time on unused transponders that cover landmasses. While it is likely there will be gaps in service coverage, Internet services should be available using these systems. This report addresses alternative methods of implementing a full duplex enhancement of the GRC developed experimental Ka-Band Direct Data Distribution (D3) space-to-ground communication link. The resulting duplex version is called the Duplex Direct Data Distribution (D4) system. The D4 system is intended to provide high-data-rate commercial direct or internet-based communications service between the NASA spacecraft in low earth orbit (LEO) and the respective principal investigators associated with these spacecraft. Candidate commercial services were assessed regarding their near-term potential to meet NASA requirements. Candidates included Ka-band and V-band geostationary orbit and non-geostationary orbit satellite relay services and direct downlink ("LEO teleport") services. End-to-end systems concepts were examined and characterized in terms of alternative link layer architectures. Alternatives included a Direct Link, a Relay Link, a Hybrid Link, and a Dual Mode Link. The direct link assessment examined sample ground terminal placements and antenna angle issues. The SATCOM-based alternatives examined existing or proposed commercial

  17. Distribution System Voltage Regulation by Distributed Energy Resources

    SciTech Connect

    Ceylan, Oguzhan; Liu, Guodong; Xu, Yan; Tomsovic, Kevin

    2014-01-01

    This paper proposes a control method to regulate voltages in 3 phase unbalanced electrical distribution systems. A constrained optimization problem to minimize voltage deviations and maximize distributed energy resource (DER) active power output is solved by harmony search algorithm. IEEE 13 Bus Distribution Test System was modified to test three different cases: a) only voltage regulator controlled system b) only DER controlled system and c) both voltage regulator and DER controlled system. The simulation results show that systems with both voltage regulators and DER control provide better voltage profile.

  18. Development of a multi-point polarization-based vibration sensor.

    PubMed

    Linze, Nicolas; Tihon, Pierre; Verlinden, Olivier; Mégret, Patrice; Wuilpart, Marc

    2013-03-11

    In this paper we propose a novel kind of multi-point vibration sensor based on the polarization properties of light. Its principle relies on the combination of mechanical transducers with fiber Bragg gratings. When subject to vibrations, the mechanical transducers induce birefringence variations within the fiber and in turn modify the state of polarization, which appears as a power variation after going through a polarizer. The FBGs reflect light from different positions of the sensing fiber and provide wavelength multiplexing. We show that this sensor can provide the vibration frequencies in a quasi-distributed manner.

  19. Building a generalized distributed system model

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi

    1991-01-01

    A number of topics related to building a generalized distributed system model are discussed. The effects of distributed database modeling on evaluation of transaction rollbacks, the measurement of effects of distributed database models on transaction availability measures, and a performance analysis of static locking in replicated distributed database systems are covered.

  20. The Planetary Data System Distributed Inventory System

    NASA Technical Reports Server (NTRS)

    Hughes, J. Steven; McMahon, Susan K.

    1996-01-01

    The advent of the World Wide Web (Web) and the ability to easily put data repositories on-line has resulted in a proliferation of digital libraries. The heterogeneity of the underlying systems, the autonomy of the individual sites, and distributed nature of the technology has made both interoperability across the sites and the search for resources within a site major research topics. This article will describe a system that addresses both issues using standard Web protocols and meta-data labels to implement an inventory of on-line resources across a group of sites. The success of this system is strongly dependent on the existence of and adherence to a standards architecture that guides the management of meta-data within participating sites.

  1. Convergence of multipoint Pade approximants of piecewise analytic functions

    SciTech Connect

    Buslaev, Viktor I

    2013-02-28

    The behaviour as n{yields}{infinity} of multipoint Pade approximants to a function which is (piecewise) holomorphic on a union of finitely many continua is investigated. The convergence of multipoint Pade approximants is proved for a function which extends holomorphically from these continua to a union of domains whose boundaries have a certain symmetry property. An analogue of Stahl's theorem is established for two-point Pade approximants to a pair of functions, either of which is a multivalued analytic function with finitely many branch points. Bibliography: 11 titles.

  2. A practical distributed Fiber Bragg grating temperature sensor system based on STM32 processor platform

    NASA Astrophysics Data System (ADS)

    Liu, Jinjun; Cheng, Yongxin; Wang, Guangyu; Zhang, Yanjun

    2015-10-01

    A practical distributed FBG temperature sensor system based on STM32 processor platform is presented in this paper and this FBG sensing system can realize single-channel and multi-point temperature measurement. Because the measured area has been divided into several parts, every part has several fiber Bragg gratings with the same wavelength. There is no need to get the temperature of each point, just get the temperature field information of the parts. In other words, if the temperature of points is varied, the largest varied temperature of the points in one part can be obtained as the temperature of this part. So in the system only use one light source, but more FBGs can be implanted in a fiber, which can effectively reduce costs and complexity. In signal processing system, the FFP-TF control circuit cans precise control without distortion of FFP-TF; high precision photoelectric detection circuit can achieve nW level optical power detection; wavelength demodulation algorithm can achieve system synchronization. The PC monitoring software based on VC++ is used to display the monitoring interface. The experiment results indicated that temperature precision is 1°C and the linearity is over 99.6%. All experiments can be reproducible. It has been seen in experiments that the system has the characteristics of the high measured stable, good reliability, low cost and can meet the needs of the engineering measurements.

  3. A distributed program composition system

    NASA Technical Reports Server (NTRS)

    Brown, Robert L.

    1989-01-01

    A graphical technique for creating distributed computer programs is investigated and a prototype implementation is described which serves as a testbed for the concepts. The type of programs under examination is restricted to those comprising relatively heavyweight parts that intercommunicate by passing messages of typed objects. Such programs are often presented visually as a directed graph with computer program parts as the nodes and communication channels as the edges. This class of programs, called parts-based programs, is not well supported by existing computer systems; much manual work is required to describe the program to the system, establish the communication paths, accommodate the heterogeneity of data types, and to locate the parts of the program on the various systems involved. The work described solves most of these problems by providing an interface for describing parts-based programs in this class in a way that closely models the way programmers think about them: using sketches of diagraphs. Program parts, the computational modes of the larger program system are categorized in libraries and are accessed with browsers. The process of programming has the programmer draw the program graph interactively. Heterogeneity is automatically accommodated by the insertion of type translators where necessary between the parts. Many decisions are necessary in the creation of a comprehensive tool for interactive creation of programs in this class. Possibilities are explored and the issues behind such decisions are presented. An approach to program composition is described, not a carefully implemented programming environment. However, a prototype implementation is described that can demonstrate the ideas presented.

  4. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Electrical Systems and Equipment § 29.1355 Distribution system. (a) The distribution system includes the distribution busses, their associated feeders, and each control and protective device. (b) If two independent sources of electrical power...

  5. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Electrical Systems and Equipment § 25.1355 Distribution system. (a) The distribution system includes the distribution busses, their associated feeders, and each control and protective device. (b) (c) If two independent sources of electrical power...

  6. Interoperability of heterogeneous distributed systems

    NASA Astrophysics Data System (ADS)

    Zaschke, C.; Essendorfer, B.; Kerth, C.

    2016-05-01

    To achieve knowledge superiority in today's operations interoperability is the key. Budget restrictions as well as the complexity and multiplicity of threats combined with the fact that not single nations but whole areas are subject to attacks force nations to collaborate and share information as appropriate. Multiple data and information sources produce different kinds of data, real time and non-real time, in different formats that are disseminated to the respective command and control level for further distribution. The data is most of the time highly sensitive and restricted in terms of sharing. The question is how to make this data available to the right people at the right time with the right granularity. The Coalition Shared Data concept aims to provide a solution to these questions. It has been developed within several multinational projects and evolved over time. A continuous improvement process was established and resulted in the adaptation of the architecture as well as the technical solution and the processes it supports. Coming from the idea of making use of existing standards and basing the concept on sharing of data through standardized interfaces and formats and enabling metadata based query the concept merged with a more sophisticated service based approach. The paper addresses concepts for information sharing to facilitate interoperability between heterogeneous distributed systems. It introduces the methods that were used and the challenges that had to be overcome. Furthermore, the paper gives a perspective how the concept could be used in the future and what measures have to be taken to successfully bring it into operations.

  7. Analysis and Multipoint Design of the TCA Concept

    NASA Technical Reports Server (NTRS)

    Krist, Steven E.; Bauer, Steven X. S.; Buning, Pieter G.

    1999-01-01

    The goal in this effort is to analyze the baseline TCA concept at transonic and supersonic cruise, then apply the natural flow wing design concept to obtain multipoint performance improvements. Analyses are conducted with OVERFLOW, a Navier-Stokes code for overset grids, using PEGSUS to compute the interpolations between the overset grids.

  8. Fabrication of multipoint light emitting optical fibers for optogenetics

    NASA Astrophysics Data System (ADS)

    Sileo, Leonardo; Pisanello, Marco; De Vittorio, Massimo; Pisanello, Ferruccio

    2015-03-01

    Multipoint Light Emitting Optical Fibers (MPF) has been recently demonstrated as a versatile tool for spatially addressable optogenetics experiments. Their fabrication has been possible thanks to a number of key microfabrication technologies, in particular the unique nanofabrication capabilities of a Focused Ion Beam. This work provides the complete description of MPF fabrication, detailing the optimization process for each fabrication step.

  9. Low jitter RF distribution system

    DOEpatents

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

    A timing signal distribution system includes an optical frequency stabilized laser signal amplitude modulated at an rf frequency. A transmitter box transmits a first portion of the laser signal and receive a modified optical signal, and outputs a second portion of the laser signal and a portion of the modified optical signal. A first optical fiber carries the first laser signal portion and the modified optical signal, and a second optical fiber carries the second portion of the laser signal and the returned modified optical signal. A receiver box receives the first laser signal portion, shifts the frequency of the first laser signal portion outputs the modified optical signal, and outputs an electrical signal on the basis of the laser signal. A detector at the end of the second optical fiber outputs a signal based on the modified optical signal. An optical delay sensing circuit outputs a data signal based on the detected modified optical signal. An rf phase detect and correct signal circuit outputs a signal corresponding to a phase stabilized rf signal based on the data signal and the frequency received from the receiver box.

  10. Strategies for Building Distributed Information Retrieval Systems.

    ERIC Educational Resources Information Center

    Macleod, Ian A.; And Others

    1987-01-01

    Discussion of the need for distributed information retrieval systems focuses on a model system, Fulcrum FUL/Text. Differences from distributed database management systems are described; system design is discussed; implementation requirements are explained including remote operation calls (ROC's); and a prototype simulation model based on FUL/Text…

  11. Computer security in DOE distributed computing systems

    SciTech Connect

    Hunteman, W.J.

    1990-01-01

    The modernization of DOE facilities amid limited funding is creating pressure on DOE facilities to find innovative approaches to their daily activities. Distributed computing systems are becoming cost-effective solutions to improved productivity. This paper defines and describes typical distributed computing systems in the DOE. The special computer security problems present in distributed computing systems are identified and compared with traditional computer systems. The existing DOE computer security policy supports only basic networks and traditional computer systems and does not address distributed computing systems. A review of the existing policy requirements is followed by an analysis of the policy as it applies to distributed computing systems. Suggested changes in the DOE computer security policy are identified and discussed. The long lead time in updating DOE policy will require guidelines for applying the existing policy to distributed systems. Some possible interim approaches are identified and discussed. 2 refs.

  12. The network and transmission of based on the principle of laser multipoint communication

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Liu, Xianzhu; Jiang, Huilin; Hu, Yuan; Jiang, Lun

    2014-11-01

    Space laser communication is the perfectly choose to the earth integrated information backbone network in the future. This paper introduces the structure of the earth integrated information network that is a large capacity integrated high-speed broadband information network, a variety of communications platforms were densely interconnected together, such as the land, sea, air and deep air users or aircraft, the technologies of the intelligent high-speed processing, switching and routing were adopt. According to the principle of maximum effective comprehensive utilization of information resources, get accurately information, fast processing and efficient transmission through inter-satellite, satellite earth, sky and ground station and other links. Namely it will be a space-based, air-based and ground-based integrated information network. It will be started from the trends of laser communication. The current situation of laser multi-point communications were expounded, the transmission scheme of the dynamic multi-point between wireless laser communication n network has been carefully studied, a variety of laser communication network transmission schemes the corresponding characteristics and scope described in detail , described the optical multiplexer machine that based on the multiport form of communication is applied to relay backbone link; the optical multiplexer-based on the form of the segmentation receiver field of view is applied to small angle link, the optical multiplexer-based form of three concentric spheres structure is applied to short distances, motorized occasions, and the multi-point stitching structure based on the rotation paraboloid is applied to inter-satellite communications in detail. The multi-point laser communication terminal apparatus consist of the transmitting and receiving antenna, a relay optical system, the spectroscopic system, communication system and communication receiver transmitter system. The communication forms of optical

  13. Water sample-collection and distribution system

    NASA Technical Reports Server (NTRS)

    Brooks, R. R.

    1978-01-01

    Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

  14. Research in Distributed Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  15. Performance related issues in distributed database systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi

    1991-01-01

    The key elements of research performed during the year long effort of this project are: Investigate the effects of heterogeneity in distributed real time systems; Study the requirements to TRAC towards building a heterogeneous database system; Study the effects of performance modeling on distributed database performance; and Experiment with an ORACLE based heterogeneous system.

  16. Intelligent Systems for Power Management and Distribution

    NASA Technical Reports Server (NTRS)

    Button, Robert M.

    2002-01-01

    The motivation behind an advanced technology program to develop intelligent power management and distribution (PMAD) systems is described. The program concentrates on developing digital control and distributed processing algorithms for PMAD components and systems to improve their size, weight, efficiency, and reliability. Specific areas of research in developing intelligent DC-DC converters and distributed switchgear are described. Results from recent development efforts are presented along with expected future benefits to the overall PMAD system performance.

  17. Multipoint and multilevel injection technique of botulinum toxin A in facial aesthetics.

    PubMed

    Iozzo, Ivano; Tengattini, Vera; Antonucci, Valentina A

    2014-06-01

    Botulinum toxin represents one of the most frequently requested cosmetic procedures. We treated 223 patients with facial wrinkles using a new technique of injection of botulinum toxin A (BTA) called multipoint and multilevel injection technique (MMIT). The aim of MMIT was to relax the muscle and not paralyze it. Patient satisfaction was evaluated by Facial Line Treatment Satisfaction Questionnaire (FTSQ). Treatment with botulinum toxin determined a good response in all patients. Facial rhytids were completely resolved in case of young skin and well reduced in case of aged skin, leaving a natural aspect both in static and dynamic wrinkles. Patient mean overall satisfaction evaluated with FTSQ was 6.4 ± 1.1. In our experience, the use of botulin toxin by MMIT consents a better calibration of action with a soft and natural result. This can be achieved by distributing the BTA dose through various injection points for each area ("multipoint injections"). Furthermore, injections can be performed at different levels ("multilevel injections"). The level of injections regulates the potency of effect on the muscle: if the level is deep (intramuscular), the effect will be strong while if it is medium or superficial (subcutaneous and intradermal), the effect will be soft. This consents a fine calibration of action on muscle activity with a personal aesthetic result.

  18. Simultaneous multipoint acoustic emission sensing using fibre acoustic wave grating sensors with identical spectrum

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ryul; Lee, Seung-Seok; Yoon, Dong-Jin

    2008-08-01

    This paper introduces the development of a simultaneous multipoint acoustic emission (AE) sensing system using a narrowband tuneable laser with high power and fibre acoustic wave grating sensors (FAWGSs). The demodulation technique is the same as that used in existing methods where the narrowband laser peak is tuned to one mid-reflection point in the main lobe of a fibre Bragg grating (FBG) spectrum. However, the sensor head is changed to an FAWGS for which a FBG is installed in a strain-free configuration so that it can detect AE waves in a structure not directly but in the form of a fibre-guided acoustic wave. Therefore since the structural strain cannot make the Bragg wavelength change, multiple FBGs with identical spectrum can be connected with multiple optical paths realized by equal light intensity dividers. The possible temperature difference between the multiple FAWGSs is passively resolved by using short FBGs which provide a wider operating temperature region. Consequently, we can resolve the problem that the FBG spectrum is easily deviated from the lasing wavelength because of the strain. In addition, the simultaneous multipoint sensing capability based on a single laser improves the cost-performance ratio of the optical system as well as reducing the structural inspection time, and enabling in situ health monitoring of real structures exposed to large and dynamic strains. The feasibility of the system is demonstrated in typical applications of in situ structural health monitoring based on AE techniques.

  19. A distributed array antenna system

    NASA Technical Reports Server (NTRS)

    Shaw, R.; Kovitz, J.

    1986-01-01

    The Space Station communication system will use microwave frequency radio links to carry digitized information from sender to receiver. The ability of the antenna system to meet stringent requirements on coverage zones, multiple users, and reliability will play an important part in the overall multiple access communication system. This paper will describe the configuration of a multibeam conformal phased array antenna and the individual microwave integrated components incoporated into this antenna system.

  20. Strategy Guideline. Compact Air Distribution Systems

    SciTech Connect

    Burdick, Arlan

    2013-06-01

    This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  1. Multipoint Observations of Magnetospheric Processes Relevant to the Substorm Events

    NASA Astrophysics Data System (ADS)

    Sibeck, D. G.; Gutynska, O.; Fok, M. C. H.

    2015-12-01

    We present several case studies of simultaneous multipoint observations of hot ion (~30-2200 keV) injections that occur during substorms in the day- and night-side of magnetosphere from THEMIS, RBSP and MMS probes. We complement them with observations of magnetic field signatures to estimate time delays of earthward plasma flows at multiple probes. We discuss the mechanisms that trigger substorm onset comparing the observations with inner plasma sheet simulations.

  2. Multipoint mapping calculations for sperm-typing data

    SciTech Connect

    Lazzeroni, L.C.; Lange, K.; Arnheim, N.; Schmitt, K.

    1994-09-01

    This paper explains how multipoint likelihoods can be computed for sperm-typing data. Experimental errors such as multiple sperm per tube, inadequate amplification, and contamination by exogenous DNA are explicitly taken into account. By limiting the number of sperm theoretically possible per tube to a predetermined maximum and by assuming no chiasma interference, maximum-likelihood estimation can be carried out rapidly using the theory of hidden Markov chains. 14 refs., 2 tabs.

  3. Lighting system with heat distribution face plate

    DOEpatents

    Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Li, Ri

    2013-09-10

    Lighting systems having a light source and a thermal management system are provided. The thermal management system includes synthetic jet devices, a heat sink and a heat distribution face plate. The synthetic jet devices are arranged in parallel to one and other and are configured to actively cool the lighting system. The heat distribution face plate is configured to radially transfer heat from the light source into the ambient air.

  4. THE LIQUID AND GASEOUS FUEL DISTRIBUTION SYSTEM

    EPA Science Inventory

    The report describes the national liquid and gaseous fuel distribution system. he study leading to the report was performed as part of an effort to better understand emissions of volatile organic compounds from the fuel distribution system. he primary, secondary, and tertiary seg...

  5. Silver disinfection in water distribution systems

    NASA Astrophysics Data System (ADS)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  6. Hybrid solar lighting distribution systems and components

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2011-07-05

    A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

  7. BIOFILMS IN DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Virtually anywhere a surface comes into contact with the water in a distribution system, one can find biofilms. Biofilms are formed in distribution system pipelines when microbial cells attach to pipe surfaces and multiply to form a film or slime layer on the pipe. Probably withi...

  8. A multi-point laser Doppler vibrometer with fiber-based configuration

    SciTech Connect

    Yang, C.; Guo, M.; Liu, H.; Yan, K.; Xu, Y. J.; Fu, Y.; Miao, H.

    2013-12-15

    Laser Doppler vibrometer (LDV) is a non-contact optical interferometric system to measure vibrations of structures and machines with a high precision. Normal LDV can only offer a single-point measurement. Scanning LDV is usually impractical to do measurement on transient events. In this paper, a fiber-based self-synchronized multi-point LDV is proposed. The multiple laser beams with different frequency shifts are generated from one laser source. The beams are projected onto a vibrating object, reflected and interfered with a common reference beam. The signal including vibration information of multiple spatial points is captured by one single-pixel photodetector. The optical system is mainly integrated by fiber components for flexibility in measurement. Two experiments are conducted to measure a steady-state simple harmonic vibration of a cantilever beam and a transient vibration of a beam clamped at both ends. In the first measurement, a numerical interpolation is applied to reconstruct the mode shape with increased number of data points. The vibration mode obtained is compared with that from FEM simulation. In transient vibration measurement, the first five resonant frequencies are obtained. The results show the new-reported fiber-based multipoint LDV can offer a vibration measurement on various spatial points simultaneously. With the flexibility of fiber configuration, it becomes more practical for dynamic structural evaluation in industrial areas.

  9. A multi-point laser Doppler vibrometer with fiber-based configuration.

    PubMed

    Yang, C; Guo, M; Liu, H; Yan, K; Xu, Y J; Miao, H; Fu, Y

    2013-12-01

    Laser Doppler vibrometer (LDV) is a non-contact optical interferometric system to measure vibrations of structures and machines with a high precision. Normal LDV can only offer a single-point measurement. Scanning LDV is usually impractical to do measurement on transient events. In this paper, a fiber-based self-synchronized multi-point LDV is proposed. The multiple laser beams with different frequency shifts are generated from one laser source. The beams are projected onto a vibrating object, reflected and interfered with a common reference beam. The signal including vibration information of multiple spatial points is captured by one single-pixel photodetector. The optical system is mainly integrated by fiber components for flexibility in measurement. Two experiments are conducted to measure a steady-state simple harmonic vibration of a cantilever beam and a transient vibration of a beam clamped at both ends. In the first measurement, a numerical interpolation is applied to reconstruct the mode shape with increased number of data points. The vibration mode obtained is compared with that from FEM simulation. In transient vibration measurement, the first five resonant frequencies are obtained. The results show the new-reported fiber-based multipoint LDV can offer a vibration measurement on various spatial points simultaneously. With the flexibility of fiber configuration, it becomes more practical for dynamic structural evaluation in industrial areas.

  10. Grid-connected distributed solar power systems

    NASA Astrophysics Data System (ADS)

    Moyle, R.; Chernoff, H.; Schweizer, T.

    This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

  11. Differences Between Distributed and Parallel Systems

    SciTech Connect

    Brightwell, R.; Maccabe, A.B.; Rissen, R.

    1998-10-01

    Distributed systems have been studied for twenty years and are now coming into wider use as fast networks and powerful workstations become more readily available. In many respects a massively parallel computer resembles a network of workstations and it is tempting to port a distributed operating system to such a machine. However, there are significant differences between these two environments and a parallel operating system is needed to get the best performance out of a massively parallel system. This report characterizes the differences between distributed systems, networks of workstations, and massively parallel systems and analyzes the impact of these differences on operating system design. In the second part of the report, we introduce Puma, an operating system specifically developed for massively parallel systems. We describe Puma portals, the basic building blocks for message passing paradigms implemented on top of Puma, and show how the differences observed in the first part of the report have influenced the design and implementation of Puma.

  12. Detecting data anomalies methods in distributed systems

    NASA Astrophysics Data System (ADS)

    Mosiej, Lukasz

    2009-06-01

    Distributed systems became most popular systems in big companies. Nowadays many telecommunications companies want to hold large volumes of data about all customers. Obviously, those data cannot be stored in single database because of many technical difficulties, such as data access efficiency, security reasons, etc. On the other hand there is no need to hold all data in one place, because companies already have dedicated systems to perform specific tasks. In the distributed systems there is a redundancy of data and each system holds only interesting data in appropriate form. Data updated in one system should be also updated in the rest of systems, which hold that data. There are technical problems to update those data in all systems in transactional way. This article is about data anomalies in distributed systems. Avail data anomalies detection methods are shown. Furthermore, a new initial concept of new data anomalies detection methods is described on the last section.

  13. Avoiding Distribution System Upgrade Costs Using Distributed Generation

    SciTech Connect

    Schienbein, Lawrence A.; Balducci, Patrick J.; Nguyen, Tony B.; Brown, Daryl R.; DeSteese, John G.; Speer, Gregory A.

    2004-01-20

    PNNL, in cooperation with three utilities, developed a database and methodology to analyze and characterize the avoided costs of Distributed Generation (DG) deployment as an alternative to traditional distribution system investment. After applying a number of screening criteria to the initial set of 307 cases, eighteen were selected for detailed analysis. Alternative DG investment scenarios were developed for these cases to permit capital, operation, maintenance, and fuel costs to be identified and incorporated into the analysis. The “customer-owned” backup power generator option was also investigated. The results of the analysis of the 18 cases show that none yielded cost savings under the alternative DG scenarios. However, the DG alternative systems were configured using very restrictive assumptions concerning reliability, peak rating, engine types and acceptable fuel. In particular it was assumed that the DG alternative in each case must meet the reliability required of conventional distribution systems (99.91% reliability). The analysis was further constrained by a requirement that each substation meet the demands placed upon it by a one in three weather occurrence. To determine if, by relaxing these requirements, the DG alternative might be more viable, one project was re-examined. The 99.91% reliability factor was still assumed for normal operating conditions but redundancy required to maintain reliability was relaxed for the relatively few hours every three years where extreme weather caused load to exceed present substation capacity. This resulted in the deferment of capital investment until later years and reduced the number of engines required for the project. The cost of both the conventional and DG alternative also dropped because the centralized power generation, variable O&M, and DG fuels costs were calculated based on present load requirements in combination with long-term forecasts of load growth, as opposed to load requirements plus a buffer

  14. Local network interconnection through a satellite point-to-multipoint link. Ph.D. Thesis - Ecole Nationale Superieure des Telecommunications, 6 Jul. 1985

    NASA Technical Reports Server (NTRS)

    Duarte, O. Muniz Bandeira

    1986-01-01

    Four architectures to implement a point to multipoint satellite link protocol for communication services offered by the Telecom 1 satellite network are presented. A safe communication service with error correction and flow control facilities is described. It is shown that a time transparent communication system combines simplicity and cost advantages.

  15. Multi-point objective-oriented sequential sampling strategy for constrained robust design

    NASA Astrophysics Data System (ADS)

    Zhu, Ping; Zhang, Siliang; Chen, Wei

    2015-03-01

    Metamodelling techniques are widely used to approximate system responses of expensive simulation models. In association with the use of metamodels, objective-oriented sequential sampling methods have been demonstrated to be effective in balancing the need for searching an optimal solution versus reducing the metamodelling uncertainty. However, existing infilling criteria are developed for deterministic problems and restricted to one sampling point in one iteration. To exploit the use of multiple samples and identify the true robust solution in fewer iterations, a multi-point objective-oriented sequential sampling strategy is proposed for constrained robust design problems. In this article, earlier development of objective-oriented sequential sampling strategy for unconstrained robust design is first extended to constrained problems. Next, a double-loop multi-point sequential sampling strategy is developed. The proposed methods are validated using two mathematical examples followed by a highly nonlinear automotive crashworthiness design example. The results show that the proposed method can mitigate the effect of both metamodelling uncertainty and design uncertainty, and identify the robust design solution more efficiently than the single-point sequential sampling approach.

  16. Visual processing of informative multipoint correlations arises primarily in V2.

    PubMed

    Yu, Yunguo; Schmid, Anita M; Victor, Jonathan D

    2015-04-27

    Using the visual system as a model, we recently showed that the efficient coding principle accounted for the allocation of computational resources in central sensory processing: when sampling an image is the main limitation, resources are devoted to compute the statistical features that are the most variable, and therefore the most informative (eLife 2014;3:e03722. DOI: 10.7554/eLife.03722 Hermundstad et al., 2014). Building on these results, we use single-unit recordings in the macaque monkey to determine where these computations--sensitivity to specific multipoint correlations--occur. We find that these computations take place in visual area V2, primarily in its supragranular layers. The demonstration that V2 neurons are sensitive to the multipoint correlations that are informative about natural images provides a common computational underpinning for diverse but well-recognized aspects of neural processing in V2, including its sensitivity to corners, junctions, illusory contours, figure/ground, and 'naturalness.'

  17. Energy optimization of water distribution systems

    SciTech Connect

    1994-09-01

    Energy costs associated with pumping treated water into the distribution system and boosting water pressures where necessary is one of the largest expenditures in the operating budget of a municipality. Due to the size and complexity of Detroit`s water transmission system, an energy optimization project has been developed to better manage the flow of water in the distribution system in an attempt to reduce these costs.

  18. Measuring advances in HVAC distribution system designs

    SciTech Connect

    Franconi, Ellen

    1998-07-01

    Substantial commercial building energy savings have been achieved by improving the performance of the HVAC distribution system. The energy savings result from distribution system design improvements, advanced control capabilities, and use of variable-speed motors. Yet, much of the commercial building stock remains equipped with inefficient systems. Contributing to this is the absence of a definition for distribution system efficiency as well as the analysis methods for quantifying performance. This research investigates the application of performance indices to assess design advancements in commercial building thermal distribution systems. The index definitions are based on a first and second law of thermodynamics analysis of the system. The second law or availability analysis enables the determination of the true efficiency of the system. Availability analysis is a convenient way to make system efficiency comparisons since performance is evaluated relative to an ideal process. A TRNSYS simulation model is developed to analyze the performance of two distribution system types, a constant air volume system and a variable air volume system, that serve one floor of a large office building. Performance indices are calculated using the simulation results to compare the performance of the two systems types in several locations. Changes in index values are compared to changes in plant energy, costs, and carbon emissions to explore the ability of the indices to estimate these quantities.

  19. Measuring Advances in HVAC Distribution System Design

    SciTech Connect

    Franconi, E.

    1998-05-01

    Substantial commercial building energy savings have been achieved by improving the performance of the HV AC distribution system. The energy savings result from distribution system design improvements, advanced control capabilities, and use of variable-speed motors. Yet, much of the commercial building stock remains equipped with inefficient systems. Contributing to this is the absence of a definition for distribution system efficiency as well as the analysis methods for quantifying performance. This research investigates the application of performance indices to assess design advancements in commercial building thermal distribution systems. The index definitions are based on a first and second law of thermodynamics analysis of the system. The second law or availability analysis enables the determination of the true efficiency of the system. Availability analysis is a convenient way to make system efficiency comparisons since performance is evaluated relative to an ideal process. A TRNSYS simulation model is developed to analyze the performance of two distribution system types, a constant air volume system and a variable air volume system, that serve one floor of a large office building. Performance indices are calculated using the simulation results to compare the performance of the two systems types in several locations. Changes in index values are compared to changes in plant energy, costs, and carbon emissions to explore the ability of the indices to estimate these quantities.

  20. Reliability improvement of distribution systems using SSVR.

    PubMed

    Hosseini, Mehdi; Shayanfar, Heidar Ali; Fotuhi-Firuzabad, Mahmoud

    2009-01-01

    This paper presents a reliability assessment algorithm for distribution systems using a Static Series Voltage Regulator (SSVR). Furthermore, this algorithm considers the effects of Distributed Generation (DG) units, alternative sources, system reconfiguration, load shedding and load adding on distribution system reliability indices. In this algorithm, load points are classified into 8 types and separated restoration times are considered for each class. Comparative studies are conducted to investigate the impacts of DG and alternative source unavailability on the distribution system reliability. For reliability assessment, the customer-oriented reliability indices such as SAIFI, SAIDI, CAIDI ASUI and also load- and energy-oriented indices such as ENS and AENS are evaluated. The effectiveness of the proposed algorithm is examined on the two standard distribution systems consisting of 33 and 69 nodes. The best location of the SSVR in distribution systems is determined based on different reliability indices, separately. Results show that the proposed algorithm is efficient for large-scale radial distribution systems and can accommodate the effects of fault isolation and load restoration. PMID:19006802

  1. Reliability mechanisms in distributed data base systems

    SciTech Connect

    Son, S.H.

    1986-01-01

    Distributed database systems operate in computer networking environments where component failures are inevitable during normal operation. Failures not only threaten normal operation of the system, but they may destroy the correctness of the data base by direct damage to the storage subsystem. In order to cope with these failures, distributed data base systems must provide reliability mechanisms that maintain the system consistency. There are two major parts in this dissertation. In the first part, mechanisms are presented for recovery management in distributed data base system. The recovery management of a distributed data bases system consists of two parts: the preparation for the recovery by saving necessary information during normal operation of the data base system, and the coordination of the actual recovery in order to avoid the possible inconsistency after the recovery. The preparation for the recovery is done through the checkpointing and logging. A new scheme is proposed for reconstruction of the data base in distributed environments. In the second part, a token-based resiliency control scheme for replicated distributed data base systems. The proposed control scheme increases the reliability as well as the degree of concurrency while maintaining the consistency of the system.

  2. Distributed-data imaging system

    SciTech Connect

    Tolmie, D.E.; Dornhoff, A.G.; DuBois, A.J.; Hodson, S.W.; Maestas, F.A.; Winkler, K.H.

    1996-05-01

    A group of eight Digital Equipment Corporation Alpha workstations is interconnected with ATM to form a cluster with supercomputer power. For output, each workstation drives a single tile on an 8-tile high- resolution frame buffer. A special purpose adapter is used to convert the workstation`s ATM format to the frame buffer`s HIPPI format. This paper discusses the rationale behind the workstation farm, and then describes the visualization output path in detail. To provide the system quickly, special emphasis was placed on making the design as simple as possible and using standard software protocols to drive and synchronize the display. The design choices are examined, and the resultant system is described.. Previously, a display could connect to a single computer; or a group of computers could drive a fragmented display, e.g., a video wall. Our system is unique in that it provides a high-quality desktop visualization display driven collectively by a group of workstations. A short video will be shown during the presentation to demonstrate the system capabilities.

  3. Development of an Integrated Distribution Management System

    SciTech Connect

    Schatz, Joe E.

    2010-10-20

    This final report details the components, functionality, costs, schedule and benefits of developing an Integrated Distribution Management System (IDMS) for power distribution system operation. The Distribution Automation (DA) and Supervisory Control and Data Acquisition (SCADA) systems used by electric power companies to manage the distribution of electric power to retail energy consumers are vital components of the Nation’s critical infrastructure. Providing electricity is an essential public service and a disruption in that service, if not quickly restored, could threaten the public safety and the Nation’s economic security. Our Nation’s economic prosperity and quality of life have long depended on the essential services that utilities provide; therefore, it is necessary to ensure that electric utilities are able to conduct their operations safely and efficiently. A fully integrated technology of applications is needed to link various remote sensing, communications and control devices with other information tools that help guide Power Distribution Operations personnel. A fully implemented IDMS will provide this, a seamlessly integrated set of applications to raise electric system operating intelligence. IDMS will enhance DA and SCADA through integration of applications such as Geographic Information Systems, Outage Management Systems, Switching Management and Analysis, Operator Training Simulator, and other Advanced Applications, including unbalanced load flow and fault isolation/service restoration. These apps are capable of utilizing and obtaining information from appropriately installed DER, and by integrating disparate systems, the Distribution Operators will benefit from advanced capabilities when analyzing, controlling and operating the electric system.

  4. BIOFILM IN DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Throughout the world there are millions of miles of water distribution pipe lines which provide potable water for use by individuals and industry. Some of these water distribution systems have been in service well over one hundred years. Treated water moving through a distributio...

  5. Distributing Executive Information Systems through Networks.

    ERIC Educational Resources Information Center

    Penrod, James I.; And Others

    1993-01-01

    Many colleges and universities will soon adopt distributed systems for executive information and decision support. Distribution of shared information through computer networks will improve decision-making processes dramatically on campuses. Critical success factors include administrative support, favorable organizational climate, ease of use,…

  6. DIstributed VIRtual System (DIVIRS) Project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford; Gaines, Stockton R.; Mizell, David

    1996-01-01

    The development of Prospero moved from the University of Washington to ISI and several new versions of the software were released from ISI during the contract period. Changes in the first release from ISI included bug fixes and extensions to support the needs of specific users. Among these changes was a new option to directory queries that allows attributes to be returned for all files in a directory together with the directory listing. This change greatly improves the performance of their server and reduces the number of packets sent across their trans-pacific connection to the rest of the internet. Several new access method were added to the Prospero file method. The Prospero Data Access Protocol was designed, to support secure retrieval of data from systems running Prospero.

  7. Distributed operating system for NASA ground stations

    NASA Technical Reports Server (NTRS)

    Doyle, John F.

    1987-01-01

    NASA ground stations are characterized by ever changing support requirements, so application software is developed and modified on a continuing basis. A distributed operating system was designed to optimize the generation and maintenance of those applications. Unusual features include automatic program generation from detailed design graphs, on-line software modification in the testing phase, and the incorporation of a relational database within a real-time, distributed system.

  8. DCLOS. Distributed Common Lisp Object System

    SciTech Connect

    Spires, S.

    1997-05-01

    DCLOS provides distributed object capabilities to CLOS. An open implementation distributed object system based upon the Common LISP Object System (CLOS) that supports proxies, copies, replicants, remote method invocation, global object identity, class coercion, object brokering, and other capabilities. Network agents use DCLOS services to exchange messages, to register in a foreign domain, and to provide automatic coercion of objects into proxies, replicants or copies.

  9. Performance TTradeoffs in Distributed Control Systems

    NASA Astrophysics Data System (ADS)

    Borowski, Holly

    Large scale systems consisting of many interacting subsystems are often controlled in a distributed fashion due to inherent limitations in computation, communication, or sensing. Here, individual agents must make decisions based on local, often incomplete information. This dissertation focuses on understanding performance tradeoffs in distributed control systems, specifically focusing on using a game theoretic framework to assign agent control laws. Performance of a distributed control law is determined by (1) the degree with which it meets a stated objective, (2) the amount of time it takes to converge, (3) agents' informational requirements, and (4) vulnerability to adversarial manipulation. The three main research questions addressed in this work are: • When is fast convergence to near-optimal behavior possible in a distributed system? We design a distributed control law which converges to a near-optimal configuration in a time that is near-linear in the number of agents. This worst case convergence time is an improvement over existing algorithms whose worst-case convergence times are exponential in the number of agents. • Can agents in a distributed system learn near-optimal correlated behavior despite severely limited information about one another's behavior? We design a distributed control law that imposes limited informational requirements for individual agents and converges to near-optimal correlated behavior. • How does the structure of agent interaction impact a distributed control system's vulnerability to adversarial manipulation? We derive a graph theoretical condition that ensures resilience to adversarial manipulation, and we examine the conditions under which an adversary can manipulate collective behavior in a distributed control system, simply by influencing small subsets of agents.

  10. Examination and characterization of distribution system biofilms.

    PubMed Central

    LeChevallier, M W; Babcock, T M; Lee, R G

    1987-01-01

    Investigations concerning the role of distribution system biofilms on water quality were conducted at a drinking water utility in New Jersey. The utility experienced long-term bacteriological problems in the distribution system, while treatment plant effluents were uniformly negative for coliform bacteria. Results of a monitoring program showed increased coliform levels as the water moved from the treatment plant through the distribution system. Increased coliform densities could not be accounted for by growth of the cells in the water column alone. Identification of coliform bacteria showed that species diversity increased as water flowed through the study area. All materials in the distribution system had high densities of heterotrophic plate count bacteria, while high levels of coliforms were detected only in iron tubercles. Coliform bacteria with the same biochemical profile were found both in distribution system biofilms and in the water column. Assimilable organic carbon determinations showed that carbon levels declined as water flowed through the study area. Maintenance of a 1.0-mg/liter free chlorine residual was insufficient to control coliform occurrences. Flushing and pigging the study area was not an effective control for coliform occurrences in that section. Because coliform bacteria growing in distribution system biofilms may mask the presence of indicator organisms resulting from a true breakdown of treatment barriers, the report recommends that efforts continue to find methods to control growth of coliform bacteria in pipeline biofilms. Images PMID:3435140

  11. Strategy Guideline: Compact Air Distribution Systems

    SciTech Connect

    Burdick, A.

    2013-06-01

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  12. DASH---Distributed Analysis System Hierarchy

    NASA Astrophysics Data System (ADS)

    Yagi, M.; Mizumoto, Y.; Yoshida, M.; Kosugi, G.; Takata, T.; Ogasawara, R.; Ishihara, Y.; Morita, Y.; Nakamoto, H.; Watanabe, N.

    We developed the Distributed Analysis Software Hierarchy (DASH), an object-oriented data reduction and data analysis system for efficient processing of data from the SUBARU telescope. DASH consists of many objects (data management objects, reduction engines, GUIs, etc.) distributed on CORBA. We have also developed SASH, a stand-alone system which has the same interface as DASH, but which does not use some of the distributed services such as DA/DB; visiting astronomers can detach PROCube out of DASH and continue the analysis with SASH at their home institute. SASH will be used as a quick reduction tool at the summit.

  13. Support for User Interfaces for Distributed Systems

    NASA Technical Reports Server (NTRS)

    Eychaner, Glenn; Niessner, Albert

    2005-01-01

    An extensible Java(TradeMark) software framework supports the construction and operation of graphical user interfaces (GUIs) for distributed computing systems typified by ground control systems that send commands to, and receive telemetric data from, spacecraft. Heretofore, such GUIs have been custom built for each new system at considerable expense. In contrast, the present framework affords generic capabilities that can be shared by different distributed systems. Dynamic class loading, reflection, and other run-time capabilities of the Java language and JavaBeans component architecture enable the creation of a GUI for each new distributed computing system with a minimum of custom effort. By use of this framework, GUI components in control panels and menus can send commands to a particular distributed system with a minimum of system-specific code. The framework receives, decodes, processes, and displays telemetry data; custom telemetry data handling can be added for a particular system. The framework supports saving and later restoration of users configurations of control panels and telemetry displays with a minimum of effort in writing system-specific code. GUIs constructed within this framework can be deployed in any operating system with a Java run-time environment, without recompilation or code changes.

  14. Multipoint NIR spectroscopy for gross composition analysis of powdered infant formula under various motion conditions.

    PubMed

    Cama-Moncunill, Raquel; Markiewicz-Keszycka, Maria; Dixit, Yash; Cama-Moncunill, Xavier; Casado-Gavalda, Maria P; Cullen, Patrick J; Sullivan, Carl

    2016-07-01

    Powdered infant formula (PIF) is a worldwide, industrially produced, human milk substitute. Manufacture of PIF faces strict quality controls in order to ensure that the product meets all compositional requirements. Near-infrared (NIR) spectroscopy is a rapid, non-destructive and well-qualified technique for food quality assessments. The use of fibre-optic NIR sensors allows measuring in-line and at real-time, and can record spectra from different stages of the process. The non-contact character of fibre-optic sensors can be enhanced by fitting collimators, which allow operation at various distances. The system, based on a Fabry-Perot interferometer, records four spectra concurrently, rather than consecutively as in the "quasi-simultaneous" multipoint NIR systems. In the present study, a novel multipoint NIR spectroscopy system equipped with four fibre-optic probes with collimators was assessed to determine carbohydrate and protein contents of PIF samples under static and motion conditions (0.02, 0.15 and 0.30m/s) to simulate possible industrial scenarios. Best results were obtained under static conditions providing a R(2) of calibration of 0.95 and RMSEP values of 1.89%. Yet, considerably low values of RMSEP, for instance 2.70% at 0.15m/s, were provided with the in-motion predictions, demonstrating the system's potential for in/on-line applications at various levels of speed. The current work also evaluated the viability of using general off-line calibrations developed under static conditions for on/in-line applications subject to motion. To this end, calibrations in both modes were developed and compared. Best results were obtained with specific calibrations; however, reasonably accurate models were obtained with the general calibration. Furthermore, this work illustrated independency of the collimator-probe setup by characterizing PIF samples simultaneously recorded according to their carbohydrate content, even when measured under different conditions. Therefore

  15. Building a generalized distributed system model

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1992-01-01

    The key elements in the second year (1991-92) of our project are: (1) implementation of the distributed system prototype; (2) successful passing of the candidacy examination and a PhD proposal acceptance by the funded student; (3) design of storage efficient schemes for replicated distributed systems; and (4) modeling of gracefully degrading reliable computing systems. In the third year of the project (1992-93), we propose to: (1) complete the testing of the prototype; (2) enhance the functionality of the modules by enabling the experimentation with more complex protocols; (3) use the prototype to verify the theoretically predicted performance of locking protocols, etc.; and (4) work on issues related to real-time distributed systems. This should result in efficient protocols for these systems.

  16. Integrating CLIPS applications into heterogeneous distributed systems

    NASA Technical Reports Server (NTRS)

    Adler, Richard M.

    1991-01-01

    SOCIAL is an advanced, object-oriented development tool for integrating intelligent and conventional applications across heterogeneous hardware and software platforms. SOCIAL defines a family of 'wrapper' objects called agents, which incorporate predefined capabilities for distributed communication and control. Developers embed applications within agents and establish interactions between distributed agents via non-intrusive message-based interfaces. This paper describes a predefined SOCIAL agent that is specialized for integrating C Language Integrated Production System (CLIPS)-based applications. The agent's high-level Application Programming Interface supports bidirectional flow of data, knowledge, and commands to other agents, enabling CLIPS applications to initiate interactions autonomously, and respond to requests and results from heterogeneous remote systems. The design and operation of CLIPS agents are illustrated with two distributed applications that integrate CLIPS-based expert systems with other intelligent systems for isolating and mapping problems in the Space Shuttle Launch Processing System at the NASA Kennedy Space Center.

  17. 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.

  18. Ionospheric Cubeswarm Concept Study: using low-resource instrumentation for truly multipoint in situ ionospheric observations

    NASA Astrophysics Data System (ADS)

    Hampton, D.; Lynch, K. A.; Earle, G. D.; Mannucci, A. J.; Clayton, R.; Fisher, L. E.; Fernandes, P. A.; Roberts, M.; Zettergren, M. D.

    2015-12-01

    Magnetosphere-ionosphere coupling currents close in the nightside lower ionosphere. These spatially inhomogeneous and time varying volume currents are difficult to capture with in situ observations. Our understanding of M-I coupling systems is limited by our understanding of the actual structure of ionospheric current closure. A path forward includes assimilation of a variety of data sets into increasingly capable ionospheric models. While each data set provides only a piece of the picture, the assimilation process allows optimal use of each piece.An important development for the necessary in situ observations involves making them truly multi-point, and therefore, low-resource. For thermal particle observations, the high densities of the lower ionosphere allow the use of low-gain (current-sensing rather than particle-counting) particle sensors. One observational goal is the definition of the actual structure of ionospheric closure currents. This can be approached with a number of different measurement techniques, in tandem with an ionospheric model, since the closure currents need to follow the rules of electrodynamics and current continuity. Low resource thermal plasma sensors such as retarding potential analyzers and drift meters can provide valuable measurements of plasma parameters, including density and plasma flow, without the need for high voltages or deployable boom systems. These low-resource measurements, which can be reproduced on arrays of in situ observation platforms, used in tandem with proper plasma physics interpretation of their signatures in the disturbed observing environment, and as part of an assimilated data set into an ionospheric model, can allow us to progress in our understanding of ionospheric structuring and its effects on auroral coupling. Now, with increasingly capable multipoint arrays of spacecraft, and quantitative 2D-with-time context from cameras and imagery, we are moving toward truly multipoint studies of the system

  19. Cost and Performance of Distributed Photovoltaic Systems

    NASA Technical Reports Server (NTRS)

    Borden, C. S.; Davisson, M. C.

    1985-01-01

    Lifetime Cost and Performance (LCP) model assists in design of Photovoltaic (PV) systems. LCP simulation of performance, cost and revenue streams associated with distributed PV power systems. Provides user with substantial flexibility in specifying technical and economic environment of PV application.

  20. Expert System Detects Power-Distribution Faults

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

    Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

  1. Data Integration in Computer Distributed Systems

    NASA Astrophysics Data System (ADS)

    Kwiecień, Błażej

    In this article the author analyze a problem of data integration in a computer distributed systems. Exchange of information between different levels in integrated pyramid of enterprise process is fundamental with regard to efficient enterprise work. Communication and data exchange between levels are not always the same cause of necessity of different network protocols usage, communication medium, system response time, etc.

  2. Distilled Water Distribution Systems. Laboratory Design Notes.

    ERIC Educational Resources Information Center

    Sell, J.C.

    Factors concerning water distribution systems, including an evaluation of materials and a recommendation of materials best suited for service in typical facilities are discussed. Several installations are discussed in an effort to bring out typical features in selected applications. The following system types are included--(1) industrial…

  3. Performance Monitoring of Distributed Data Processing Systems

    NASA Technical Reports Server (NTRS)

    Ojha, Anand K.

    2000-01-01

    Test and checkout systems are essential components in ensuring safety and reliability of aircraft and related systems for space missions. A variety of systems, developed over several years, are in use at the NASA/KSC. Many of these systems are configured as distributed data processing systems with the functionality spread over several multiprocessor nodes interconnected through networks. To be cost-effective, a system should take the least amount of resource and perform a given testing task in the least amount of time. There are two aspects of performance evaluation: monitoring and benchmarking. While monitoring is valuable to system administrators in operating and maintaining, benchmarking is important in designing and upgrading computer-based systems. These two aspects of performance evaluation are the foci of this project. This paper first discusses various issues related to software, hardware, and hybrid performance monitoring as applicable to distributed systems, and specifically to the TCMS (Test Control and Monitoring System). Next, a comparison of several probing instructions are made to show that the hybrid monitoring technique developed by the NIST (National Institutes for Standards and Technology) is the least intrusive and takes only one-fourth of the time taken by software monitoring probes. In the rest of the paper, issues related to benchmarking a distributed system have been discussed and finally a prescription for developing a micro-benchmark for the TCMS has been provided.

  4. The NATO III 5 MHz Distribution System

    NASA Technical Reports Server (NTRS)

    Vulcan, A.; Bloch, M.

    1981-01-01

    A high performance 5 MHz distribution system is described which has extremely low phase noise and jitter characteristics and provides multiple buffered outputs. The system is completely redundant with automatic switchover and is self-testing. Since the 5 MHz reference signals distributed by the NATO III distribution system are used for up-conversion and multiplicative functions, a high degree of phase stability and isolation between outputs is necessary. Unique circuit design and packaging concepts insure that the isolation between outputs is sufficient to quarantee a phase perturbation of less than 0.0016 deg when other outputs are open circuited, short circuited or terminated in 50 ohms. Circuit design techniques include high isolation cascode amplifiers. Negative feedback stabilizes system gain and minimizes circuit phase noise contributions. Balanced lines, in lieu of single ended coaxial transmission media, minimize pickup.

  5. Optical Characterization of a Multipoint Lean Direct Injector for Gas Turbine Combustors: Velocity and Fuel Drop Size Measurements

    NASA Technical Reports Server (NTRS)

    Heath, Christopher M.; Anderson, Robert C.; Locke, Randy J.; Hicks, Yolanda R.

    2010-01-01

    Performance of a multipoint, lean direct injection (MP-LDI) strategy for low emission aero-propulsion systems has been tested in a Jet-A fueled, lean flame tube combustion rig. Operating conditions for the series of tests included inlet air temperatures between 672 and 828 K, pressures between 1034 and 1379 kPa and total equivalence ratios between 0.41 and 0.45, resulting in equilibrium flame temperatures approaching 1800 K. Ranges of operation were selected to represent the spectrum of subsonic and supersonic flight conditions projected for the next-generation of commercial aircraft. This document reports laser-based measurements of in situ fuel velocities and fuel drop sizes for the NASA 9-point LDI hardware arranged in a 3 3 square grid configuration. Data obtained represent a region of the flame tube combustor with optical access that extends 38.1-mm downstream of the fuel injection site. All data were obtained within reacting flows, without particle seeding. Two diagnostic methods were employed to evaluate the resulting flow path. Three-component velocity fields have been captured using phase Doppler interferometry (PDI), and two-component velocity distributions using planar particle image velocimetry (PIV). Data from these techniques have also offered insight into fuel drop size and distribution, fuel injector spray angle and pattern, turbulence intensity, degree of vaporization and extent of reaction. This research serves to characterize operation of the baseline NASA 9- point LDI strategy for potential use in future gas-turbine combustor applications. An additional motive is the compilation of a comprehensive database to facilitate understanding of combustor fuel injector aerodynamics and fuel vaporization processes, which in turn may be used to validate computational fluid dynamics codes, such as the National Combustor Code (NCC), among others.

  6. Work distribution in a photonic system

    NASA Astrophysics Data System (ADS)

    Talarico, M. A. A.; Monteiro, P. B.; Mattei, E. C.; Duzzioni, E. I.; Souto Ribeiro, P. H.; Céleri, L. C.

    2016-10-01

    We present a proposal of a setup to measure the work distribution of a process acting on a quantum system emulated by the transverse degrees of freedom of classical light. Hermite-Gaussian optical modes are used to represent the energy eigenstates of a quantum harmonic oscillator prepared in a thermal state. The Fourier transform of the work distribution, or the characteristic function, can be obtained by measuring the light intensity at the output of a properly designed interferometer. The usefulness of the approach is illustrated by calculating the work distribution for a unitary operation that displaces the linear momentum of the oscillator. Other types of processes and quantum systems can be implemented with the same scheme. We also show that the setup can be used to investigate the energy distribution for open dynamics described by completely positive maps. We discuss the feasibility of the experiment, which can be realized with simple linear optical components.

  7. Exploiting virtual synchrony in distributed systems

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Joseph, Thomas A.

    1987-01-01

    Applications of a virtually synchronous environment are described for distributed programming, which underlies a collection of distributed programming tools in the ISIS2 system. A virtually synchronous environment allows processes to be structured into process groups, and makes events like broadcasts to the group as an entity, group membership changes, and even migration of an activity from one place to another appear to occur instantaneously, in other words, synchronously. A major advantage to this approach is that many aspects of a distributed application can be treated independently without compromising correctness. Moreover, user code that is designed as if the system were synchronous can often be executed concurrently. It is argued that this approach to building distributed and fault tolerant software is more straightforward, more flexible, and more likely to yield correct solutions than alternative approaches.

  8. Distributed Storage Systems for Data Intensive Computing

    SciTech Connect

    Vazhkudai, Sudharshan S; Butt, Ali R; Ma, Xiaosong

    2012-01-01

    In this chapter, the authors present an overview of the utility of distributed storage systems in supporting modern applications that are increasingly becoming data intensive. Their coverage of distributed storage systems is based on the requirements imposed by data intensive computing and not a mere summary of storage systems. To this end, they delve into several aspects of supporting data-intensive analysis, such as data staging, offloading, checkpointing, and end-user access to terabytes of data, and illustrate the use of novel techniques and methodologies for realizing distributed storage systems therein. The data deluge from scientific experiments, observations, and simulations is affecting all of the aforementioned day-to-day operations in data-intensive computing. Modern distributed storage systems employ techniques that can help improve application performance, alleviate I/O bandwidth bottleneck, mask failures, and improve data availability. They present key guiding principles involved in the construction of such storage systems, associated tradeoffs, design, and architecture, all with an eye toward addressing challenges of data-intensive scientific applications. They highlight the concepts involved using several case studies of state-of-the-art storage systems that are currently available in the data-intensive computing landscape.

  9. Energy optimization of water distribution system

    SciTech Connect

    Not Available

    1993-02-01

    In order to analyze pump operating scenarios for the system with the computer model, information on existing pumping equipment and the distribution system was collected. The information includes the following: component description and design criteria for line booster stations, booster stations with reservoirs, and high lift pumps at the water treatment plants; daily operations data for 1988; annual reports from fiscal year 1987/1988 to fiscal year 1991/1992; and a 1985 calibrated KYPIPE computer model of DWSD`s water distribution system which included input data for the maximum hour and average day demands on the system for that year. This information has been used to produce the inventory database of the system and will be used to develop the computer program to analyze the system.

  10. Updating multipoint simulations using the ensemble Kalman filter

    NASA Astrophysics Data System (ADS)

    Hu, L. Y.; Zhao, Y.; Liu, Y.; Scheepens, C.; Bouchard, A.

    2013-02-01

    In the last two decades, the multipoint simulation (MPS) method has been developed and increasingly used for building complex geological facies models that are conditioned to geological and geophysical data. In the meantime, the ensemble Kalman filter (EnKF) approach has been developed and recognized as a promising way for assimilating dynamic production data into reservoir models. So far, the EnKF approach is proven efficient for updating continuous model parameters that have a linear statistical relation with the flow responses. It remains challenging to extend the EnKF approach to updating complex geological facies models generated by MPS, while preserving their geological and statistical consistency. In this paper, we introduce a new method for parameterizing geostatistical reservoir models generated by MPS. It is mathematically proven that updating these parameters during a history matching process does not compromise the hard data conditioning and the geological and statistical consistency of the reservoir model defined by the training image and other information including global facies proportions, trend maps etc. This method is an alternative to the gradual deformation method but has an enlarged search space for covering possible solutions. Based on the above parameterization, we present two algorithms of using EnKF approach to update multipoint simulations to dynamic data. We also present results of using the above methodology to condition a sector model of a fluvial reservoir to dynamic data.

  11. Microbial ecology of drinking water distribution systems.

    PubMed

    Berry, David; Xi, Chuanwu; Raskin, Lutgarde

    2006-06-01

    The supply of clean drinking water is a major, and relatively recent, public health milestone. Control of microbial growth in drinking water distribution systems, often achieved through the addition of disinfectants, is essential to limiting waterborne illness, particularly in immunocompromised subpopulations. Recent inquiries into the microbial ecology of distribution systems have found that pathogen resistance to chlorination is affected by microbial community diversity and interspecies relationships. Research indicates that multispecies biofilms are generally more resistant to disinfection than single-species biofilms. Other recent findings are the increased survival of the bacterial pathogen Legionella pneumophila when present inside its protozoan host Hartmannella vermiformis and the depletion of chloramine disinfectant residuals by nitrifying bacteria, leading to increased overall microbial growth. Interactions such as these are unaccounted for in current disinfection models. An understanding of the microbial ecology of distribution systems is necessary to design innovative and effective control strategies that will ensure safe and high-quality drinking water. PMID:16701992

  12. Standard Data Exchanges for Distribution System Management

    SciTech Connect

    Thomas E. McDermott

    2007-10-05

    Databases and software tools for electric power distribution systems have not been integrated, and this leads to extra costs and restrictions imposed on utilities and other stakeholders. For example, distributed resource integration studies and modern grid technology assessments are more difficult and costly. New vendors face high market entry barriers, because it’s necessary to interface with large and customized data systems at each potential utility customer. This project promotes data and software tool integration, through a set of data translators based on a common object model. The data translators are delivered as open-source software, using appropriate Web software technologies. The parties who benefit include electric utilities (and their ratepayers), researchers at government laboratories and universities, small software companies wishing to enter the electric utility market, and parties wishing to interconnect distributed generation to a utility system.

  13. 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.

  14. Distributed Object Oriented Geographic Information System

    1997-02-01

    This interactive, object-oriented, distributed Geographic Information System (GIS) uses the World Wibe Web (WWW) as application medium and distribution mechanism. The software provides distributed access to multiple geo-spatial databases and presents them as if they came from a single coherent database. DOOGIS distributed access comes not only in the form of multiple geo-spatial servers but can break down a single logical server into the constituent physical servers actually storing the data. The program provides formore » dynamic protocol resolution and content handling allowing unknown objects from a particular server to download their handling code. Security and access privileges are negotiated dynamically with each server contacted and each access attempt.« less

  15. Deceit: A flexible distributed file system

    NASA Technical Reports Server (NTRS)

    Siegel, Alex; Birman, Kenneth; Marzullo, Keith

    1989-01-01

    Deceit, a distributed file system (DFS) being developed at Cornell, focuses on flexible file semantics in relation to efficiency, scalability, and reliability. Deceit servers are interchangeable and collectively provide the illusion of a single, large server machine to any clients of the Deceit service. Non-volatile replicas of each file are stored on a subset of the file servers. The user is able to set parameters on a file to achieve different levels of availability, performance, and one-copy serializability. Deceit also supports a file version control mechanism. In contrast with many recent DFS efforts, Deceit can behave like a plain Sun Network File System (NFS) server and can be used by any NFS client without modifying any client software. The current Deceit prototype uses the ISIS Distributed Programming Environment for all communication and process group management, an approach that reduces system complexity and increases system robustness.

  16. Interfaces for Distributed Systems of Information Servers.

    ERIC Educational Resources Information Center

    Kahle, Brewster M.; And Others

    1993-01-01

    Describes five interfaces to remote, full-text databases accessed through distributed systems of servers. These are WAIStation for the Macintosh, XWAIS for X-Windows, GWAIS for Gnu-Emacs; SWAIS for dumb terminals, and Rosebud for the Macintosh. Sixteen illustrations provide examples of display screens. Problems and needed improvements are…

  17. Ray tracing on distributed memory parallel systems

    NASA Technical Reports Server (NTRS)

    Jensen, David W.; Reed, Daniel A.

    1990-01-01

    Among the many techniques in computer graphics, ray tracing is prized because it can render realistic images, albeit at great computational expense. In this note, the performance of several approaches to ray tracing on a distributed memory parallel system is evaluated. A set of performance instrumentation tools and their associated visualization software are used to identify the underlying causes of performance differences.

  18. Harmonic analysis of electrical distribution systems

    SciTech Connect

    1996-03-01

    This report presents data pertaining to research on harmonics of electric power distribution systems. Harmonic data is presented on RMS and average measurements for determination of harmonics in buildings; fluorescent ballast; variable frequency drive; georator geosine harmonic data; uninterruptible power supply; delta-wye transformer; westinghouse suresine; liebert datawave; and active injection mode filter data.

  19. COST FOR WATER SUPPLY DISTRIBUTION SYSTEM REHABILITATION

    EPA Science Inventory

    A major challenge for the society in the twenty-first century will be design, rehabilitation, replacement, and optimal management of drinking water distribution systems. A recent survey conducted by the USEPA found that $138B will be needed to maintain and replace existing drinki...

  20. Laser spark distribution and ignition system

    DOEpatents

    Woodruff, Steven; McIntyre, Dustin L.

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  1. Distribution of Quantum Coherence in Multipartite Systems.

    PubMed

    Radhakrishnan, Chandrashekar; Parthasarathy, Manikandan; Jambulingam, Segar; Byrnes, Tim

    2016-04-15

    The distribution of coherence in multipartite systems is examined. We use a new coherence measure with entropic nature and metric properties, based on the quantum Jensen-Shannon divergence. The metric property allows for the coherence to be decomposed into various contributions, which arise from local and intrinsic coherences. We find that there are trade-off relations between the various contributions of coherence, as a function of parameters of the quantum state. In bipartite systems the coherence resides on individual sites or is distributed among the sites, which contribute in a complementary way. In more complex systems, the characteristics of the coherence can display more subtle changes with respect to the parameters of the quantum state. In the case of the XXZ Heisenberg model, the coherence changes from a monogamous to a polygamous nature. This allows us to define the shareability of coherence, leading to monogamy relations for coherence. PMID:27127948

  2. Data distribution satellite system architecture concept

    NASA Technical Reports Server (NTRS)

    Price, Kent M.; Jorasch, Ronald E.

    1990-01-01

    This paper describes a future communications satellite system architecture concept called the Data Distribution Satellite (DDS). The DDS is envisioned as a new system to be used as an adjunct to TDRS/TDAS for distributing new NASA science data throughout the U.S. as well as internationally. The DDS would also provide networking capability for interchange of science database files among science users and NASA archive depositories. Experimenters would be able to access and control their experimental packages remotely, relieving astronaut workload. This paper gives a conceptual system design based on year 1995 technology. Features of the design include use of Ku and Ka-bands, use of fixed spot beams, 2 Gb/s throughput, and on-board demodulation and switching. The satellite dry mass is 1,300 kg and end-of-life power is 4 kW.

  3. Data reprocessing on worldwide distributed systems

    SciTech Connect

    Diesburg, Mike; Wicke, Daniel; /Fermilab

    2004-12-01

    The D0 experiment faces many challenges enabling access to large datasets for physicists on 4 continents. The strategy followed is to make use of worldwide distributed computing clusters. Since the begin of Tevatron Run-II (March 2001) all Monte-Carlo simulations are produced outside of Fermilab on remote systems. For analyses a system of regional analysis centres (RACs) was established which supply the associated institutes with the data. This structure which is similar to the Tier structure foreseen for LHC was used in autumn 2003 to reprocess all D0-data with the up-to-date and much improved reconstruction software. With these achievements D0 is the first high energy physics experiment to have implemented and operated all essential computing tasks on non-dedicated, worldwide distributed systems. The experiences gained in D0 can be applied to evaluate the LHC computing model.

  4. Data reprocessing on worldwide distributed systems

    SciTech Connect

    Wicke, Daniel; /Fermilab

    2004-12-01

    The D0 experiment faces many challenges in terms of enabling access to large datasets for physicists on four continents. The strategy for solving these problems on worldwide distributed computing clusters is presented. Since the beginning of Run II of the Tevatron (March 2001) all Monte-Carlo simulations for the experiment have been produced at remote systems. For data analysis, a system of regional analysis centers (RACs) was established which supply the associated institutes with the data. This structure, which is similar to the tiered structure foreseen for the LHC was used in Fall 2003 to reprocess all D0 data with a much improved version of the reconstruction software. This makes D0 the first running experiment that has implemented and operated all important computing tasks of a high energy physics experiment on systems distributed worldwide.

  5. Distributed parallel messaging for multiprocessor systems

    SciTech Connect

    Chen, Dong; Heidelberger, Philip; Salapura, Valentina; Senger, Robert M; Steinmacher-Burrow, Burhard; Sugawara, Yutaka

    2013-06-04

    A method and apparatus for distributed parallel messaging in a parallel computing system. The apparatus includes, at each node of a multiprocessor network, multiple injection messaging engine units and reception messaging engine units, each implementing a DMA engine and each supporting both multiple packet injection into and multiple reception from a network, in parallel. The reception side of the messaging unit (MU) includes a switch interface enabling writing of data of a packet received from the network to the memory system. The transmission side of the messaging unit, includes switch interface for reading from the memory system when injecting packets into the network.

  6. The message processing and distribution system development

    NASA Astrophysics Data System (ADS)

    Whitten, K. L.

    1981-06-01

    A historical approach is used in presenting the life cycle development of the Navy's message processing and distribution system beginning with the planning phase and ending with the integrated logistic support phase. Several maintenance problems which occurred after the system was accepted for fleet use were examined to determine if they resulted from errors in the acquisition process. The critical decision points of the acquisition process are examined and constructive recommendations are made for avoiding the problems which hindered the successful development of this system.

  7. Distributed control system for active mirrors

    NASA Astrophysics Data System (ADS)

    Rodriguez-Ramos, Luis F.; Williams, Mark R.; Castro, Javier; Cruz, A.; Gonzalez, Juan C.; Mack, Brian; Martin, Carlos; Pescador, German; Sanchez, Vicente; Sosa, Nicolas A.

    1994-06-01

    This paper presents the IAC (Instituto de Astrofisica de Canaries, Spain) proposal of a distributed control system intended for the active support of a 8 m mirror. The system incorporates a large number of compact `smart' force actuators, six force definers, and a mirror support computer (MSC) for interfacing with the telescope control system and for general housekeeping. We propose the use of a network for the interconnection of the actuators, definers and the MSC, which will minimize the physical complexity of the interface between the mirror support system and the MSC. The force actuator control electronics are described in detail, as is the system software architecture of the actuator and the MSC. As the network is a key point for the system, we also detail the evaluation of three candidates, before electing the CAN bus.

  8. Multipoint Observations of Oval-aligned Transpolar Arc Formation

    NASA Astrophysics Data System (ADS)

    Cumnock, J. A.; Le, G.; Zhang, Y.; Slavin, J. A.

    2013-12-01

    We analyze changes in field-aligned currents associated with auroral oval-aligned transpolar arc formation during quiet times on time scales of a few minutes. This is accomplished using observations from the highly accurate multipoint magnetic field measurements provided by the Space Technology 5 mission which consists of three micro-satellites in low Earth orbit. Simultaneous measurements of precipitating particles are provided by three DMSP satellites. We analyze field-aligned currents associated with the dusk oval. For the first time we observe the field-aligned currents associated with the formation of an oval-aligned transpolar arc poleward of the auroral oval which in one case are large compared with the field-aligned currents associated with the auroral oval measured 10 minutes earlier. These events clearly illustrate the dynamic nature of oval-aligned arc formation.

  9. Multipoint measurements of energetic particles in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Baker, D. N.

    1988-01-01

    The benefits of energetic-particle measurements in the study of magnetospheric physics are reviewed, including the particles' relative ease of detection, their high rectilinear speed, their range of gyroradii, and their immunity to large-scale electric fields. With such particles, it is possible to observationally separate distinctive plasma regions, uniquely assess field-line topologies, examine connectivity from the magnetospheric equator to the ionosphere, and sense global changes in magnetospheric configuration. Multipoint measurements of energetic particles have contributed substantially to the understanding of the earth magnetopause, the leakage of particles into the upstream region, the effect of sudden storm compressions, the global nature of substorm dynamics, and the location and character of high-energy acceleration processes.

  10. Representation of chromatic distribution for lighting system

    NASA Astrophysics Data System (ADS)

    Rossi, Maurizio; Musante, Fulvio

    2015-01-01

    For the luminaire manufacturer, the measurement of the lighting intensity distribution (LID) emitted by lighting fixture is based on photometry. So light is measured as an achromatic value of intensity and there is no the possibility to discriminate the measurement of white vs. colored light. At the Laboratorio Luce of Politecnico di Milano a new instrument for the measurement of spectral radiant intensities distribution for lighting system has been built: the goniospectra- radiometer. This new measuring tool is based on a traditional mirror gonio-photometer with a CCD spectraradiometer controlled by a PC. Beside the traditional representation of photometric distribution we have introduced a new representation where, in addition to the information about the distribution of luminous intensity in space, new details about the chromaticity characteristic of the light sources have been implemented. Some of the results of this research have been applied in developing and testing a new line of lighting system "My White Light" (the research project "Light, Environment and Humans" funded in the Italian Lombardy region Metadistretti Design Research Program involving Politecnico di Milano, Artemide, Danese, and some other SME of the Lighting Design district), giving scientific notions and applicative in order to support the assumption that colored light sources can be used for the realization of interior luminaries that, other than just have low power consumption and long life, may positively affect the mood of people.

  11. A system for distributed intrusion detection

    SciTech Connect

    Snapp, S.R.; Brentano, J.; Dias, G.V.; Goan, T.L.; Heberlein, L.T.; Ho, Che-Lin; Levitt, K.N.; Mukherjee, B. . Div. of Computer Science); Grance, T. ); Mansur, D.L.; Pon, K.L. ); Smaha, S.E. )

    1991-01-01

    The study of providing security in computer networks is a rapidly growing area of interest because the network is the medium over which most attacks or intrusions on computer systems are launched. One approach to solving this problem is the intrusion-detection concept, whose basic premise is that not only abandoning the existing and huge infrastructure of possibly-insecure computer and network systems is impossible, but also replacing them by totally-secure systems may not be feasible or cost effective. Previous work on intrusion-detection systems were performed on stand-alone hosts and on a broadcast local area network (LAN) environment. The focus of our present research is to extend our network intrusion-detection concept from the LAN environment to arbitarily wider areas with the network topology being arbitrary as well. The generalized distributed environment is heterogeneous, i.e., the network nodes can be hosts or servers from different vendors, or some of them could be LAN managers, like our previous work, a network security monitor (NSM), as well. The proposed architecture for this distributed intrusion-detection system consists of the following components: a host manager in each host; a LAN manager for monitoring each LAN in the system; and a central manager which is placed at a single secure location and which receives reports from various host and LAN managers to process these reports, correlate them, and detect intrusions. 11 refs., 2 figs.

  12. 47 CFR 73.6023 - Distributed transmission systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Distributed transmission systems. 73.6023... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission... distributed transmission system....

  13. 47 CFR 73.6023 - Distributed transmission systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Distributed transmission systems. 73.6023... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission... distributed transmission system....

  14. 47 CFR 73.6023 - Distributed transmission systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Distributed transmission systems. 73.6023... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission... distributed transmission system....

  15. 47 CFR 73.6023 - Distributed transmission systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Distributed transmission systems. 73.6023... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission... distributed transmission system....

  16. Electric power distribution and load transfer system

    NASA Technical Reports Server (NTRS)

    Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

    1989-01-01

    A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

  17. Electric power distribution and load transfer system

    NASA Technical Reports Server (NTRS)

    Bradford, Michael P. (Inventor); Parkinson, Gerald W. (Inventor); Grant, Ross M. (Inventor)

    1987-01-01

    A power distribution system includes a plurality of power sources and load transfer units including transistors and diodes connected in series and leading to a common power output, each of the transistors being controller switchable subject to voltage levels of the respective input and output sides of said transistors, and the voltage and current level of said common power output. The system is part of an interconnection scheme in which all but one of the power sources is connected to a single load transfer unit, enabling the survival of at least a single power source with the failure of one of the load transfer units.

  18. Neutron chain length distributions in subcritical systems

    SciTech Connect

    Nolen, S.D.; Spriggs, G.

    1999-09-27

    In this paper, the authors present the results of the chain-length distribution as a function of k in subcritical systems. These results were obtained from a point Monte Carlo code and a three-dimensional Monte Carlo code, MC++. Based on these results, they then attempt to explain why several of the common neutron noise techniques, such as the Rossi-{alpha} and Feynman's variance-to-mean techniques, are difficult to perform in highly subcritical systems using low-efficiency detectors.

  19. Distributed Power Electronics for PV Systems (Presentation)

    SciTech Connect

    Deline, C.

    2011-12-01

    An overview of the benefits and applications of microinverters and DC power optimizers in residential systems. Some conclusions from this report are: (1) The impact of shade is greater than just the area of shade; (2) Additional mismatch losses include panel orientation, panel distribution, inverter voltage window, soiling; (3) Per-module devices can help increase performance, 4-12% or more depending on the system; (4) Value-added benefits (safety, monitoring, reduced design constraints) are helping their adoption; and (5) The residential market is growing rapidly. Efficiency increases, cost reductions are improving market acceptance. Panel integration will further reduce price and installation cost. Reliability remains an unknown.

  20. Petri net controllers for distributed robotic systems

    NASA Technical Reports Server (NTRS)

    Lefebvre, D. R.; Saridis, George N.

    1992-01-01

    Petri nets are a well established modelling technique for analyzing parallel systems. When coupled with an event-driven operating system, Petri nets can provide an effective means for integrating and controlling the functions of distributed robotic applications. Recent work has shown that Petri net graphs can also serve as remarkably intuitive operator interfaces. In this paper, the advantages of using Petri nets as high-level controllers to coordinate robotic functions are outlined, the considerations for designing Petri net controllers are discussed, and simple Petri net structures for implementing an interface for operator supervision are presented. A detailed example is presented which illustrates these concepts for a sensor-based assembly application.

  1. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems (Neutral grounded). (a) If a grounded distribution system is provided, there must be only one connection to... 46 Shipping 4 2013-10-01 2013-10-01 false Grounded distribution systems (Neutral grounded)....

  2. Disinfection of water distribution systems for Legionella.

    PubMed

    Lin, Y S; Stout, J E; Yu, V L; Vidic, R D

    1998-06-01

    Hospital-acquired legionnaires' disease arises from the presence of Legionella in hospital water systems. Legionella not only persists in hot water tanks but is also found in the biofilm throughout the entire water distribution system. Conditions within water systems that promote Legionella colonization include water temperature, configuration and age of the hot water tank, physicochemical constituents of the water, plumbing materials, and commensal microflora. Hospital-acquired legionnaires' disease has been prevented by instituting control measures directed at the water distribution system. These include superheat-and-flush, copper/silver ionization, ultraviolet light, instantaneous heating systems, and hyperchlorination. Each of the above disinfection methods has been proven to be effective in the short-term, but long-term efficacy has been difficult due to limitations associated with each method. The complexities of Legionella disinfection, including advantages and disadvantages of each method, are reviewed. A successful Legionella prevention program requires cooperation and communication among hospital administrative personnel, engineers, and infection control staff. Routine environmental surveillance cultures for Legionella are the critical component for successful long-term disinfection. Culture results document the efficacy of the disinfection method and alert the hospital staff to consider Legionella in hospitalized patients with pneumonia. PMID:9643393

  3. DASH--distributed analysis system hierarchy

    NASA Astrophysics Data System (ADS)

    Yagi, Masafumi; Yoshihiko, Mizumoto; Ogasawara, Ryusuke; Kosugi, George; Takata, Tadafumi; Ishihara, Yasuhide; Yokono, Yasunori; Morita, Yasuhiro; Nakamoto, Hiroyuki; Watanabe, Noboru; Ukawa, Kentaro

    2002-12-01

    We have developed and are operating an object-oriented data reduction and data analysis system, DASH ( Distributed Analysis Software Hierarchy ), for efficient data processing for SUBARU telescope. In DASH, all information for reducing a set of data is packed into an abstracted object, named as ``Hierarchy''. It contains rules how to search calibration data, reduction procedure to the final result, and also the reduction log. With Hierarchy, DASH works as an automated reduction pipeline platform cooperated with STARS (Subaru Telescope ARchive System). DASH is implemented on CORBA and Java technology. The portability of these technology enables us to make a subset of the system for a small stand-alone system, SASH. SASH is compatible with DASH and one can continuously reduce and analyze data between DASH and SASH.

  4. Smart Operations in Distributed Energy Resources System

    NASA Astrophysics Data System (ADS)

    Wei, Li; Jie, Shu; Zhang-XianYong; Qing, Zhou

    Smart grid capabilities are being proposed to help solve the challenges concerning system operations due to that the trade-offs between energy and environmental needs will be constantly negotiated while a reliable supply of electricity needs even greater assurance in case of that threats of disruption have risen. This paper mainly explores models for distributed energy resources system (DG, storage, and load),and also reviews the evolving nature of electricity markets to deal with this complexity and a change of emphasis on signals from these markets to affect power system control. Smart grid capabilities will also impact reliable operations, while cyber security issues must be solved as a culture change that influences all system design, implementation, and maintenance. Lastly, the paper explores significant questions for further research and the need for a simulation environment that supports such investigation and informs deployments to mitigate operational issues as they arise.

  5. Rapid multipoint linkage analysis of recessive traits in nuclear families, including homozygosity mapping

    SciTech Connect

    Kruglyak, L.; Daly, M.J.; Lander, E.S. |

    1995-02-01

    Homozygosity mapping is a powerful strategy for mapping rare recessive traits in children of consanguineous marriages. Practical applications of this strategy are currently limited by the inability of conventional linkage analysis software to compute, in reasonable time, multipoint LOD scores for pedigrees with inbreeding loops. We have developed a new algorithm for rapid multipoint likelihood calculations in small pedigrees, including those with inbreeding loops. The running time of the algorithm grows, at most, linearly with the number of loci considered simultaneously. The running time is not sensitive to the presence of inbreeding loops, missing genotype information, and highly polymorphic loci. We have incorporated this algorithm into a software package, MAPMAKER/HOMOZ, that allows very rapid multipoint mapping of disease genes in nuclear families, including homozygosity mapping. Multipoint analysis with dozens of markers can be carried out in minutes on a personal workstation. 23 refs., 4 figs., 1 tab.

  6. Automated distribution system management for multichannel space power systems

    NASA Technical Reports Server (NTRS)

    Fleck, G. W.; Decker, D. K.; Graves, J.

    1983-01-01

    A NASA sponsored study of space power distribution system technology is in progress to develop an autonomously managed power system (AMPS) for large space power platforms. The multichannel, multikilowatt, utility-type power subsystem proposed presents new survivability requirements and increased subsystem complexity. The computer controls under development for the power management system must optimize the power subsystem performance and minimize the life cycle cost of the platform. A distribution system management philosophy has been formulated which incorporates these constraints. Its implementation using a TI9900 microprocessor and FORTH as the programming language is presented. The approach offers a novel solution to the perplexing problem of determining the optimal combination of loads which should be connected to each power channel for a versatile electrical distribution concept.

  7. High-resolution wave number spectrum using multi-point measurements in space - the Multi-point Signal Resonator (MSR) technique

    NASA Astrophysics Data System (ADS)

    Narita, Y.; Glassmeier, K.-H.; Motschmann, U.

    2011-02-01

    A new analysis method is presented that provides a high-resolution power spectrum in a broad wave number domain based on multi-point measurements. The analysis technique is referred to as the Multi-point Signal Resonator (MSR) and it benefits from Capon's minimum variance method for obtaining the proper power spectral density of the signal as well as the MUSIC algorithm (Multiple Signal Classification) for considerably reducing the noise part in the spectrum. The mathematical foundation of the analysis method is presented and it is applied to synthetic data as well as Cluster observations of the interplanetary magnetic field. Using the MSR technique for Cluster data we find a wave in the solar wind propagating parallel to the mean magnetic field with relatively small amplitude, which is not identified by the Capon spectrum. The Cluster data analysis shows the potential of the MSR technique for studying waves and turbulence using multi-point measurements.

  8. Evaluation of a multi-point method for determining acoustic impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Parrott, Tony L.

    1988-01-01

    An investigation was conducted to explore potential improvements provided by a Multi-Point Method (MPM) over the Standing Wave Method (SWM) and Two-Microphone Method (TMM) for determining acoustic impedance. A wave propagation model was developed to model the standing wave pattern in an impedance tube. The acoustic impedance of a test specimen was calculated from a best fit of this standing wave pattern to pressure measurements obtained along the impedance tube centerline. Three measurement spacing distributions were examined: uniform, random, and selective. Calculated standing wave patterns match the point pressure measurement distributions with good agreement for a reflection factor magnitude range of 0.004 to 0.999. Comparisons of results using 2, 3, 6, and 18 measurement points showed that the most consistent results are obtained when using at least 6 evenly spaced pressure measurements per half-wavelength. Also, data were acquired with broadband noise added to the discrete frequency noise and impedances were calculated using the MPM and TMM algorithms. The results indicate that the MPM will be superior to the TMM in the presence of significant broadband noise levels associated with mean flow.

  9. FRIB Cryogenic Distribution System and Status

    NASA Astrophysics Data System (ADS)

    Ganni, V.; Dixon, K.; Laverdure, N.; Yang, S.; Nellis, T.; Jones, S.; Casagrande, F.

    2015-12-01

    The MSU-FRIB cryogenic distribution system supports the 2 K primary, 4 K primary, and 35 - 55 K shield operation of more than 70 loads in the accelerator and the experimental areas. It is based on JLab and SNS experience with bayonet-type disconnects between the loads and the distribution system for phased commissioning and maintenance. The linac transfer line, which features three separate transfer line segments for additional independence during phased commissioning at 4 K and 2 K, connects the folded arrangement of 49 cryomodules and 4 superconducting dipole magnets and a fourth transfer line supports the separator area cryo loads. The pressure reliefs for the transfer line process lines, located in the refrigeration room outside the tunnel/accelerator area, are piped to be vented outdoors. The transfer line designs integrate supply and return flow paths into a combined vacuum space. The main linac distribution segments are produced in a small number of standard configurations; a prototype of one such configuration has been fabricated at Jefferson Lab and has been installed at MSU to support testing of a prototype FRIB cryomodule.

  10. Velocity distribution in active particles systems

    PubMed Central

    Marconi, Umberto Marini Bettolo; Gnan, Nicoletta; Paoluzzi, Matteo; Maggi, Claudio; Di Leonardo, Roberto

    2016-01-01

    We derive an analytic expression for the distribution of velocities of multiple interacting active particles which we test by numerical simulations. In clear contrast with equilibrium we find that the velocities are coupled to positions. Our model shows that, even for two particles only, the individual velocities display a variance depending on the interparticle separation and the emergence of correlations between the velocities of the particles. When considering systems composed of many particles we find an analytic expression connecting the overall velocity variance to density, at the mean-field level, and to the pair distribution function valid in the limit of small noise correlation times. Finally we discuss the intriguing analogies and main differences between our effective free energy functional and the theoretical scenario proposed so far for phase-separating active particles. PMID:27001289

  11. Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors.

    PubMed

    Chiuchiolo, Antonella; Palmieri, Luca; Consales, Marco; Giordano, Michele; Borriello, Anna; Bajas, Hugues; Galtarossa, Andrea; Bajko, Marta; Cusano, Andrea

    2015-10-01

    This contribution presents distributed and multipoint fiber-optic monitoring of cryogenic temperatures along a superconducting power transmission line down to 30 K and over 20 m distance. Multipoint measurements were conducted using fiber Bragg gratings sensors coated with two different functional overlays (epoxy and poly methyl methacrylate (PMMA)) demonstrating cryogenic operation in the range 300-4.2 K. Distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimide). The integrated system has been placed along the 20 m long cryostat of a superconducting power transmission line, which is currently being tested at the European Organization for Nuclear Research (CERN). Cool-down events from 300-30 K have been successfully measured in space and time, confirming the viability of these approaches to the monitoring of cryogenic temperatures along a superconducting transmission line. PMID:26421547

  12. System approach to distributed sensor management

    NASA Astrophysics Data System (ADS)

    Mayott, Gregory; Miller, Gordon; Harrell, John; Hepp, Jared; Self, Mid

    2010-04-01

    Since 2003, the US Army's RDECOM CERDEC Night Vision Electronic Sensor Directorate (NVESD) has been developing a distributed Sensor Management System (SMS) that utilizes a framework which demonstrates application layer, net-centric sensor management. The core principles of the design support distributed and dynamic discovery of sensing devices and processes through a multi-layered implementation. This results in a sensor management layer that acts as a System with defined interfaces for which the characteristics, parameters, and behaviors can be described. Within the framework, the definition of a protocol is required to establish the rules for how distributed sensors should operate. The protocol defines the behaviors, capabilities, and message structures needed to operate within the functional design boundaries. The protocol definition addresses the requirements for a device (sensors or processes) to dynamically join or leave a sensor network, dynamically describe device control and data capabilities, and allow dynamic addressing of publish and subscribe functionality. The message structure is a multi-tiered definition that identifies standard, extended, and payload representations that are specifically designed to accommodate the need for standard representations of common functions, while supporting the need for feature-based functions that are typically vendor specific. The dynamic qualities of the protocol enable a User GUI application the flexibility of mapping widget-level controls to each device based on reported capabilities in real-time. The SMS approach is designed to accommodate scalability and flexibility within a defined architecture. The distributed sensor management framework and its application to a tactical sensor network will be described in this paper.

  13. Next Generation Multimedia Distributed Data Base Systems

    NASA Technical Reports Server (NTRS)

    Pendleton, Stuart E.

    1997-01-01

    The paradigm of client/server computing is changing. The model of a server running a monolithic application and supporting clients at the desktop is giving way to a different model that blurs the line between client and server. We are on the verge of plunging into the next generation of computing technology--distributed object-oriented computing. This is not only a change in requirements but a change in opportunities, and requires a new way of thinking for Information System (IS) developers. The information system demands caused by global competition are requiring even more access to decision making tools. Simply, object-oriented technology has been developed to supersede the current design process of information systems which is not capable of handling next generation multimedia.

  14. Building a generalized distributed system model

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1993-01-01

    The key elements in the 1992-93 period of the project are the following: (1) extensive use of the simulator to implement and test - concurrency control algorithms, interactive user interface, and replica control algorithms; and (2) investigations into the applicability of data and process replication in real-time systems. In the 1993-94 period of the project, we intend to accomplish the following: (1) concentrate on efforts to investigate the effects of data and process replication on hard and soft real-time systems - especially we will concentrate on the impact of semantic-based consistency control schemes on a distributed real-time system in terms of improved reliability, improved availability, better resource utilization, and reduced missed task deadlines; and (2) use the prototype to verify the theoretically predicted performance of locking protocols, etc.

  15. Distributed-aperture infrared sensor systems

    NASA Astrophysics Data System (ADS)

    Brusgard, Thomas C.

    1999-07-01

    The on-going maturation of electro-optic technology in which the advent of third generation focal plane array is being combined with the capabilities of increasingly powerful signal processing algorithm now points to a new direction in design of electro-optic sensor system for both military and non-military applications. Taking advantage of those advances. Distributed Aperture IR Sensor systems (DAIRS) are currently in development within the Defense Department for installation in a variety of platforms for utilization in a wide variety of tactical scenarios. DAIRS employs multiple fixed identical sensor to obtain the functionality that was previously obtained using specialized sensors for each function. In its role in tactical scenarios. DAIRS employs multiple fixed identical sensor to obtain the functionality that was previously obtained using specialized sensor for each function. In its role in tactical aircraft, DAIRS uses an array of six strategically located sensors which provide 4(pi) steradian sensor coverage, i.e., full sphere situational awareness (SA), to the aircrew. That awareness provides: missile threat warning, IR Search and Track, battle damage assessment, targeting assistance, and pilotage. DAIRS has applicability in providing expanded SA for surface ships, armored land vehicles and unmanned air combat vehicles. A typical sensor design has less than twenty-five percent of the weight, volume, and electrical power demand of current federated airborne IR sensor system and can become operational with a significant reduction in lifetime system cost. DAIRS, when combined with autocueing, may have a significant role in technological advancement of aircraft proximity warning system for in-flight collision avoidance. DAIRS is currently founded in part by the Office of Naval Research which will result in the IR Distributed Aperture System (MIDAS), which is funded as a Navy Advanced Technology Demonstration, the DAIRS will undergo airborne testing using four

  16. Epidemiology of urban water distribution systems

    NASA Astrophysics Data System (ADS)

    Bardet, Jean-Pierre; Little, Richard

    2014-08-01

    Urban water distribution systems worldwide contain numerous old and fragile pipes that inevitably break, flood streets and damage property, and disrupt economic and social activities. Such breaks often present dramatically in temporal clusters as occurred in Los Angeles during 2009. These clustered pipe breaks share many characteristics with human mortality observed during extreme climatological events such as heat waves or air pollution. Drawing from research and empirical studies in human epidemiology, a framework is introduced to analyze the time variations of disruptive pipe breaks that can help water agencies better understand clustered pipe failures and institute measures to minimize the disruptions caused by them. It is posited that at any time, a cohort of the pipes comprising the water distribution system will be in a weakened state due to fatigue and corrosion. This frail cohort becomes vulnerable during normal operations and ultimately breaks due to rapid increase in crack lengths induced by abnormal stressors. The epidemiological harvesting model developed in this paper simulates an observed time series of monthly pipe breaks and has both explanatory and predictive power. It also demonstrates that models from nonengineering disciplines such as medicine can provide improved insights into the performance of infrastructure systems.

  17. Galileo spacecraft power management and distribution system

    NASA Technical Reports Server (NTRS)

    Detwiler, R. C.; Smith, R. L.

    1990-01-01

    The Galileo PMAD (power management and distribution system) is described, and the design drivers that established the final as-built hardware are discussed. The spacecraft is powered by two general-purpose heat-source-radioisotope thermoelectric generators. Power bus regulation is provided by a shunt regulator. Galileo PMAD distributes a 570-W beginning of mission (BOM) power source to a user complement of some 137 load elements. Extensive use of pyrotechnics requires two pyro switching subassemblies. They initiate 148 squibs which operate the 47 pyro devices on the spacecraft. Detection and correction of faults in the Galileo PMAD is an autonomous feature dictated by requirements for long life and reliability in the absence of ground-based support. Volatile computer memories in the spacecraft command and data system and attitude control system require a continuous source of backup power during all anticipated power bus fault scenarios. Power for the Jupiter Probe is conditioned, isolated, and controlled by a Probe interface subassembly. Flight performance of the spacecraft and the PMAD has been successful to date, with no major anomalies.

  18. 47 CFR 73.6023 - Distributed transmission systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... systems. Station licensees may operate a commonly owned group of digital Class A stations with contiguous... 47 Telecommunication 4 2010-10-01 2010-10-01 false Distributed transmission systems. 73.6023... distributed transmission system....

  19. Test report light duty utility arm power distribution system (PDS)

    SciTech Connect

    Clark, D.A.

    1996-03-04

    The Light Duty Utility Arm (LDUA) Power Distribution System has completed vendor and post-delivery acceptance testing. The Power Distribution System has been found to be acceptable and is now ready for integration with the overall LDUA system.

  20. Distributed Online Learning in Social Recommender Systems

    NASA Astrophysics Data System (ADS)

    Tekin, Cem; Zhang, Simpson; van der Schaar, Mihaela

    2014-08-01

    In this paper, we consider decentralized sequential decision making in distributed online recommender systems, where items are recommended to users based on their search query as well as their specific background including history of bought items, gender and age, all of which comprise the context information of the user. In contrast to centralized recommender systems, in which there is a single centralized seller who has access to the complete inventory of items as well as the complete record of sales and user information, in decentralized recommender systems each seller/learner only has access to the inventory of items and user information for its own products and not the products and user information of other sellers, but can get commission if it sells an item of another seller. Therefore the sellers must distributedly find out for an incoming user which items to recommend (from the set of own items or items of another seller), in order to maximize the revenue from own sales and commissions. We formulate this problem as a cooperative contextual bandit problem, analytically bound the performance of the sellers compared to the best recommendation strategy given the complete realization of user arrivals and the inventory of items, as well as the context-dependent purchase probabilities of each item, and verify our results via numerical examples on a distributed data set adapted based on Amazon data. We evaluate the dependence of the performance of a seller on the inventory of items the seller has, the number of connections it has with the other sellers, and the commissions which the seller gets by selling items of other sellers to its users.

  1. Distributed, cooperating knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt

    1991-01-01

    Some current research in the development and application of distributed, cooperating knowledge-based systems technology is addressed. The focus of the current research is the spacecraft ground operations environment. The underlying hypothesis is that, because of the increasing size, complexity, and cost of planned systems, conventional procedural approaches to the architecture of automated systems will give way to a more comprehensive knowledge-based approach. A hallmark of these future systems will be the integration of multiple knowledge-based agents which understand the operational goals of the system and cooperate with each other and the humans in the loop to attain the goals. The current work includes the development of a reference model for knowledge-base management, the development of a formal model of cooperating knowledge-based agents, the use of testbed for prototyping and evaluating various knowledge-based concepts, and beginning work on the establishment of an object-oriented model of an intelligent end-to-end (spacecraft to user) system. An introductory discussion of these activities is presented, the major concepts and principles being investigated are highlighted, and their potential use in other application domains is indicated.

  2. Hot Water Distribution System Model Enhancements

    SciTech Connect

    Hoeschele, M.; Weitzel, E.

    2012-11-01

    This project involves enhancement of the HWSIM distribution system model to more accurately model pipe heat transfer. Recent laboratory testing efforts have indicated that the modeling of radiant heat transfer effects is needed to accurately characterize piping heat loss. An analytical methodology for integrating radiant heat transfer was implemented with HWSIM. Laboratory test data collected in another project was then used to validate the model for a variety of uninsulated and insulated pipe cases (copper, PEX, and CPVC). Results appear favorable, with typical deviations from lab results less than 8%.

  3. Databases in parallel and distributed systems

    SciTech Connect

    Agrawal, R. ); Bell, D. )

    1990-01-01

    The existence of this Symposium, and the success of the First Symposium acknowledge the growing recognition of the importance of two related challenges for database systems as we enter the 1990s. One is to exploit the potential for flexibility of access to dispersed data which may preexist at nodes of a computer network, or are distributed for some other reason. The other is to meet the often stringent performance requirements for some database queries by invoking the support of parallel architectures based on recent hardware and software developments.

  4. Storage and distribution system for multimedia information

    NASA Astrophysics Data System (ADS)

    Murakami, Tokumichi

    1994-06-01

    Recent advances in technologies such as digital signal processing, LSI devices and storage media have led to an explosive growth in multimedia environment. Multimedia information services are expected to provide an information-oriented infrastructure which will integrate visual communication, broadcasting and computer services. International standardizations in video/audio coding accelerate permeation of these services into society. In this paper, from trends of R & D and international standardization in video coding techniques, an outline is given of a storage and distribution system for multimedia information, and a summary of the requirements of digital storage media.

  5. Analysis and control of distributed cooperative systems.

    SciTech Connect

    Feddema, John Todd; Parker, Eric Paul; Wagner, John S.; Schoenwald, David Alan

    2004-09-01

    As part of DARPA Information Processing Technology Office (IPTO) Software for Distributed Robotics (SDR) Program, Sandia National Laboratories has developed analysis and control software for coordinating tens to thousands of autonomous cooperative robotic agents (primarily unmanned ground vehicles) performing military operations such as reconnaissance, surveillance and target acquisition; countermine and explosive ordnance disposal; force protection and physical security; and logistics support. Due to the nature of these applications, the control techniques must be distributed, and they must not rely on high bandwidth communication between agents. At the same time, a single soldier must easily direct these large-scale systems. Finally, the control techniques must be provably convergent so as not to cause undo harm to civilians. In this project, provably convergent, moderate communication bandwidth, distributed control algorithms have been developed that can be regulated by a single soldier. We have simulated in great detail the control of low numbers of vehicles (up to 20) navigating throughout a building, and we have simulated in lesser detail the control of larger numbers of vehicles (up to 1000) trying to locate several targets in a large outdoor facility. Finally, we have experimentally validated the resulting control algorithms on smaller numbers of autonomous vehicles.

  6. Multipoint Grout Injection System. Innovative Technology Summary Report

    SciTech Connect

    2001-09-01

    At the Oak Ridge Reservation (ORR), radioactive waste contained in the 16 cylindrical Gunite and Associated Tanks (GAATs) must retrieved so the tanks can be closed. In many cases, removing the small amounts of sludge that remain in the tank after the bulk of the waste is retrieved is extremely costly and provides little benefit from site health and environmental standpoints. The Tanks Focus Area is working with ORR's M and I contractor (Bechtel-Jacobs), Oak Ridge National Laboratory, and Ground Environmental Services to demonstrate the application of multi-point-injection (MPI) grout emplacement technology for horizontal cylindrical tanks during a cold demonstration in FY99. GAAT TH-4 has been identified as the tank to be used for the hot demonstration in FY00. Evaluation efforts continue on the effect of slag on strength performance of the grout to be used in TH-4 tank closure. The site must find out what level of slag can be accommodated in the grout while maintaining strength performance requirements. Other efforts in support of the utilization of MPI TM technology in large-scale waste tanks will continue. Also, ORR is collaborating with SRS to evaluate the use this technology to support grouting of the Old Burial Ground tanks at SRS.

  7. Distributed fiber optic moisture intrusion sensing system

    DOEpatents

    Weiss, Jonathan D.

    2003-06-24

    Method and system for monitoring and identifying moisture intrusion in soil such as is contained in landfills housing radioactive and/or hazardous waste. The invention utilizes the principle that moist or wet soil has a higher thermal conductance than dry soil. The invention employs optical time delay reflectometry in connection with a distributed temperature sensing system together with heating means in order to identify discrete areas within a volume of soil wherein temperature is lower. According to the invention an optical element and, optionally, a heating element may be included in a cable or other similar structure and arranged in a serpentine fashion within a volume of soil to achieve efficient temperature detection across a large area or three dimensional volume of soil. Remediation, moisture countermeasures, or other responsive action may then be coordinated based on the assumption that cooler regions within a soil volume may signal moisture intrusion where those regions are located.

  8. Remote procedure execution software for distributed systems

    SciTech Connect

    Petravick, D.L.; Berman, E.F.; Sergey, G.P.

    1989-05-01

    Remote Procedure Execution facilitates the construction of distributed software systems, spanning computers of various types. Programmers who use the RPX package specify subroutine calls which are to be executed on a remote computer. RPX is used to generate code for dummy routines which transmit input parameters and receive output parameters, as well as a main program which receives procedure call requests, calls the requested procedure, and returns the result. The package automatically performs datatype conversions and uses an appropriate connection oriented protocol. Supported operating systems/processors are VMS(VAX), UNIX(MIPS R2000, R3000) and Software Components Group's pSOS (680x0). Connection oriented protocols are supported over Ethernet (TCP/IP) and RS232 (a package of our own design). 2 refs., 2 figs.

  9. Distributed health care imaging information systems

    NASA Astrophysics Data System (ADS)

    Thompson, Mary R.; Johnston, William E.; Guojun, Jin; Lee, Jason; Tierney, Brian; Terdiman, Joseph F.

    1997-05-01

    We have developed an ATM network-based system to collect and catalogue cardio-angiogram videos from the source at a Kaiser central facility and make them available for viewing by doctors at primary care Kaiser facilities. This an example of the general problem of diagnostic data being generated at tertiary facilities, while the images, or other large data objects they produce, need to be used from a variety of other locations such as doctor's offices or local hospitals. We describe the use of a highly distributed computing and storage architecture to provide all aspects of collecting, storing, analyzing, and accessing such large data-objects in a metropolitan area ATM network. Our large data-object management system provides network interface between the object sources, the data management system and the user of the data. As the data is being stored, a cataloguing system automatically creates and stores condensed versions of the data, textural metadata and pointers to the original data. The catalogue system provides a Web-based graphical interface to the data. The user is able the view the low-resolution data with a standard Internet connection and Web browser. If high-resolution is required, a high-speed connection and special application programs can be used to view the high-resolution original data.

  10. CODA: A scalable, distributed data acquisition system

    SciTech Connect

    Watson, W.A. III; Chen, J.; Heyes, G.; Jastrzembski, E.; Quarrie, D. )

    1994-02-01

    A new data acquisition system has been designed for physics experiments scheduled to run at CEBAF starting in the summer of 1994. This system runs on Unix workstations connected via ethernet, FDDI, or other network hardware to multiple intelligent front end crates -- VME, CAMAC or FASTBUS. CAMAC crates may either contain intelligent processors, or may be interfaced to VME. The system is modular and scalable, from a single front end crate and one workstation linked by ethernet, to as may as 32 clusters of front end crates ultimately connected via a high speed network to a set of analysis workstations. The system includes an extensible, device independent slow controls package with drivers for CAMAC, VME, and high voltage crates, as well as a link to CEBAF accelerator controls. All distributed processes are managed by standard remote procedure calls propagating change-of-state requests, or reading and writing program variables. Custom components may be easily integrated. The system is portable to any front end processor running the VxWorks real-time kernel, and to most workstations supplying a few standard facilities such as rsh and X-windows, and Motif and socket libraries. Sample implementations exist for 2 Unix workstation families connected via ethernet or FDDI to VME (with interfaces to FASTBUS or CAMAC), and via ethernet to FASTBUS or CAMAC.

  11. CODA: a scalable, distributed data acquisition system

    SciTech Connect

    David Quarrie; Edward Jastrzembski; William Heyes; Jie Chen; William Watson

    1994-02-01

    A new data acquisition system has been designed for physics experiments scheduled to run at CEBAF starting in the summer of 1994. This system runs on Unix workstations connected via ethernet, FDDI, or other network hardware to multiple intelligent front end crates-VME, CAMAC or FASTBUS. CAMAC crates may either contain intelligent processors, or may be interfaced to VME. The system is modular and scalable, from a single front end crate and one workstation linked by ethernet, to as many as 32 clusters of front end crates ultimately connected via a high speed network to a set of analysis workstations. The system includes an extensible, device independent slow controls package with drivers for CAMAC, VME, and high voltage crates, as well as a link to CEBAF accelerator controls. All distributed processes are managed by standard remote procedure calls propagating change-of-state requests, or reading and writing program variables. Custom components may be easily integrated. The system is portable to any front end processor running the VxWorks real-time kernel, and to most workstations supplying a few standard facilities such as rsh and X-windows, and Motif and socket libraries. Sample implementations exist for 2 Unix workstation families connected via ethernet or FDDI to VME (with interfaces to FASTBUS or CAMAC), and via ethernet to FASTBUS or CAMAC

  12. Distributed intelligence for ground/space systems

    NASA Technical Reports Server (NTRS)

    Aarup, Mads; Munch, Klaus Heje; Fuchs, Joachim; Hartmann, Ralf; Baud, Tim

    1994-01-01

    DI is short for Distributed Intelligence for Ground/Space Systems and the DI Study is one in a series of ESA projects concerned with the development of new concepts and architectures for future autonomous spacecraft systems. The kick-off of DI was in January 1994 and the planned duration is three years. The background of DI is the desire to design future ground/space systems with a higher degree of autonomy than seen in today's missions. The aim of introducing autonomy in spacecraft systems is to: (1) lift the role of the spacecraft operators from routine work and basic troubleshooting to supervision; (2) ease access to and increase availability of spacecraft resources; (3) carry out basic mission planning for users; (4) enable missions which have not yet been feasible due to eg. propagation delays, insufficient ground station coverage etc.; and (5) possibly reduce mission cost. The study serves to identify the feasibility of using state-of-the-art technologies in the area of planning, scheduling, fault detection using model-based diagnosis and knowledge processing to obtain a higher level of autonomy in ground/space systems.

  13. Broadcasting Systems: An Advanced CATV System with Wireless Distribution

    NASA Astrophysics Data System (ADS)

    Tsuzuku, Aiichiro

    2001-12-01

    CATV(Community Antenna TV) has been started as a measure intended to improve the poor reception area since 1955 at the spa of lkaho in Gunma prefecture. Recently CATV has come into the limelight as a multi program distributor and a new transmission media of the broadband Internet. The percentage of household CATV sets is 22% in 2000 in Japan. The wireless distributed CATV system is able to complement the wired system. It is serviceable in where the cable cannot lay, such as the area studded with houses or isolated island. In this paper, an advanced CATV system with wireless distribution is mentioned. The frequency band is the millimeter-wave band, because it has the characteristic of allowing broadband transmission and miniaturization of devices. The link budget of the test system using 60-GHz band is also described.

  14. Simulation of Soil Macropore Networks Using Multi-Point Geostatistics

    NASA Astrophysics Data System (ADS)

    Luo, L.; Lin, H.; Singha, K.

    2006-12-01

    Two-point correlation functions have been used to quantitatively evaluate the spatial variability of soil structure but cannot characterize its specific geometry. Multi-point (MP) geostatistics can be used to consider both spatial correlation and the specific shape of objects. The algorithm, SNESIM, developed by Strebelle (2002) was used to simulate complex geological patterns, reflecting different scales of variability and types of heterogeneity. Soil macropores, especially earthworm burrows and root channels, are critical to preferential flow and transport in soils. Accurate simulation of soil macropore network can allow us better simulate soil hydraulic properties and address scaling issues of structured soils. However, little work has been done to simulate soil macropore network using MP geostatistics. 3D soil macropore network of an agricultural soil in Pennsylvania, Hagerstown silt loam, was extracted from the spatially exhaustive data collected with Micro Computing Tomography. 3D training image was scanned by 3D template to obtain the 3D patterns. Permeability of the simulated macropore network was calculated using Lattice-Boltzmann method. SNESIM was able to simulate different types of macropores, the earthworm burrows and inter-aggregate pores. However, SNESIM requires that training images must have a stationary character, which may limit its ability to simulate soil macropore network. SNESIM is still very computationally consuming for the 3D structure simulation. While computationally expensive, MP geostatistics has great potential for simulating 3D soil macropore network, which is useful to understand and predict the hydraulic behavior of structured soils.

  15. Dynamic Loads Generation for Multi-Point Vibration Excitation Problems

    NASA Technical Reports Server (NTRS)

    Shen, Lawrence

    2011-01-01

    A random-force method has been developed to predict dynamic loads produced by rocket-engine random vibrations for new rocket-engine designs. The method develops random forces at multiple excitation points based on random vibration environments scaled from accelerometer data obtained during hot-fire tests of existing rocket engines. This random-force method applies random forces to the model and creates expected dynamic response in a manner that simulates the way the operating engine applies self-generated random vibration forces (random pressure acting on an area) with the resulting responses that we measure with accelerometers. This innovation includes the methodology (implementation sequence), the computer code, two methods to generate the random-force vibration spectra, and two methods to reduce some of the inherent conservatism in the dynamic loads. This methodology would be implemented to generate the random-force spectra at excitation nodes without requiring the use of artificial boundary conditions in a finite element model. More accurate random dynamic loads than those predicted by current industry methods can then be generated using the random force spectra. The scaling method used to develop the initial power spectral density (PSD) environments for deriving the random forces for the rocket engine case is based on the Barrett Criteria developed at Marshall Space Flight Center in 1963. This invention approach can be applied in the aerospace, automotive, and other industries to obtain reliable dynamic loads and responses from a finite element model for any structure subject to multipoint random vibration excitations.

  16. Multipoint observations of Ionospheric Alfvén Resonance

    NASA Astrophysics Data System (ADS)

    Baru, N. A.; Koloskov, A. V.; Yampolsky, Y. M.; Rakhmatulin, R. A.

    2016-09-01

    Among the processes that form properties of the geospace in the circumterrestrial plasma the electromagnetic resonances of the Earth, such as Schummann Resonance (SR) and Ionospheric Alfvén Resonance (IAR) are of great importance. IAR is more localized in space than SR and its properties largely depend on the characteristics of the propagation medium. In contrast to the SR, which has global nature and which is continuously observable at any time of the day, IAR signals are registered mostly during the nighttime and demonstrate more variability of the parameters than SR signals. At the Earth surface IAR is registered as Spectral Resonance Structure of the natural electromagnetic noise at frequency range 0.1-40 Hz. In this work we studied an influence of the environment characteristics on IAR parameters by the means of multipoint observations. Annual data series recorded at Ukrainian Antarctic Station "Akademik Vernadsky", Low Frequency Observatory of the Institute of Radio Astronomy near Kharkov (Ukraine) and magnetic station of Sayan Solar Observatory Mondy near Irkutsk (Russia) were used for the analysis. We investigated the behaviour of IAR parameters, such as probability of resonance lines registration and frequency spacing Δ F, for annual and diurnal intervals. These parameters were compared with characteristics of the ionosphere above all of the observation points and geomagnetic activity.

  17. Development of a Multi-Point Microwave Interferometry (MPMI) Method

    SciTech Connect

    Specht, Paul Elliott; Cooper, Marcia A.; Jilek, Brook Anton

    2015-09-01

    A multi-point microwave interferometer (MPMI) concept was developed for non-invasively tracking a shock, reaction, or detonation front in energetic media. Initially, a single-point, heterodyne microwave interferometry capability was established. The design, construction, and verification of the single-point interferometer provided a knowledge base for the creation of the MPMI concept. The MPMI concept uses an electro-optic (EO) crystal to impart a time-varying phase lag onto a laser at the microwave frequency. Polarization optics converts this phase lag into an amplitude modulation, which is analyzed in a heterodyne interfer- ometer to detect Doppler shifts in the microwave frequency. A version of the MPMI was constructed to experimentally measure the frequency of a microwave source through the EO modulation of a laser. The successful extraction of the microwave frequency proved the underlying physical concept of the MPMI design, and highlighted the challenges associated with the longer microwave wavelength. The frequency measurements made with the current equipment contained too much uncertainty for an accurate velocity measurement. Potential alterations to the current construction are presented to improve the quality of the measured signal and enable multiple accurate velocity measurements.

  18. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must...

  19. A Parallel Framework for Multipoint Spiral Search in ab Initio Protein Structure Prediction

    PubMed Central

    Rashid, Mahmood A.; Newton, M. A. Hakim; Hoque, Md Tamjidul; Sattar, Abdul

    2014-01-01

    Protein structure prediction is computationally a very challenging problem. A large number of existing search algorithms attempt to solve the problem by exploring possible structures and finding the one with the minimum free energy. However, these algorithms perform poorly on large sized proteins due to an astronomically wide search space. In this paper, we present a multipoint spiral search framework that uses parallel processing techniques to expedite exploration by starting from different points. In our approach, a set of random initial solutions are generated and distributed to different threads. We allow each thread to run for a predefined period of time. The improved solutions are stored threadwise. When the threads finish, the solutions are merged together and the duplicates are removed. A selected distinct set of solutions are then split to different threads again. In our ab initio protein structure prediction method, we use the three-dimensional face-centred-cubic lattice for structure-backbone mapping. We use both the low resolution hydrophobic-polar energy model and the high-resolution 20 × 20 energy model for search guiding. The experimental results show that our new parallel framework significantly improves the results obtained by the state-of-the-art single-point search approaches for both energy models on three-dimensional face-centred-cubic lattice. We also experimentally show the effectiveness of mixing energy models within parallel threads. PMID:24744779

  20. Multi-Point Themis Observations of Multiple Transient Ion Foreshock Phenomena

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Turner, D. L.; Angelopoulos, V.; Omidi, N.

    2014-12-01

    Recent simulations and observations have shown that when solar wind rotational discontinuities (RDs) approaching Earth's bow shock interact with ions backstreaming in the foreshock they can result in a new phenomenon, foreshock bubbles (FBs). FBs result in very intense pressure perturbations upstream of and inside Earth's magnetosphere and are therefore important for solar wind-magnetosphere coupling. To examine the time evolution of FBs and compare FBs with hot flow anomalies (HFAs), we examined multi-point THEMIS observations of both FBs and HFAs in which 4 or more spacecraft all observed the same events. Such observations allow us to disambiguate between spatial and temporal evolution of the FBs and HFAs. Our results show that FBs form further upstream from the bow shock and then expand with a higher speed to a much larger size compared to HFAs. We discuss how these results are consistent with simulations. Particle acceleration caused by the bouncing motion of particles between the earthward moving shock upstream of the FBs and the Earth's bow shock as revealed in simulations is also discussed based on our observations of ion distribution functions.

  1. Stability Analysis of Distributed Order Fractional Chen System

    PubMed Central

    Aminikhah, H.; Refahi Sheikhani, A.; Rezazadeh, H.

    2013-01-01

    We first investigate sufficient and necessary conditions of stability of nonlinear distributed order fractional system and then we generalize the integer-order Chen system into the distributed order fractional domain. Based on the asymptotic stability theory of nonlinear distributed order fractional systems, the stability of distributed order fractional Chen system is discussed. In addition, we have found that chaos exists in the double fractional order Chen system. Numerical solutions are used to verify the analytical results. PMID:24489508

  2. Multi-point optical manipulation and simultaneous imaging of neural circuits through wavefront phase modulation (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Aghayee, Samira; Winkowski, Dan; Kanold, Patrick; Losert, Wolfgang

    2015-08-01

    The spatial connectivity of neural circuits and the various activity patterns they exert is what forms the brain function. How these patterns link to a certain perception or a behavior is a key question in neuroscience. Recording the activity of neural circuits while manipulating arbitrary neurons leads to answering this question. That is why acquiring a fast and reliable method of stimulation and imaging a population of neurons at a single cell resolution is of great importance. Owing to the recent advancements in calcium imaging and optogenetics, tens to hundreds of neurons in a living system can be imaged and manipulated optically. We describe the adaptation of a multi-point optical method that can be used to address the specific challenges faced in the in-vivo study of neuronal networks in the cerebral cortex. One specific challenge in the cerebral cortex is that the information flows perpendicular to the surface. Therefore, addressing multiple points in a three dimensional space simultaneously is of great interest. Using a liquid crystal spatial light modulator, the wavefront of the input laser beam is modified to produce multiple focal points at different depths of the sample for true multipoint two-photon excitation.

  3. Fabry-Pérot cavity sensors for multipoint on-column micro gas chromatography detection.

    PubMed

    Liu, Jing; Sun, Yuze; Howard, Daniel J; Frye-Mason, Greg; Thompson, Aaron K; Ja, Shiou-Jyh; Wang, Siao-Kwan; Bai, Mengjun; Taub, Haskell; Almasri, Mahmoud; Fan, Xudong

    2010-06-01

    We developed and characterized a Fabry-Pérot (FP) sensor module based micro gas chromatography (microGC) detector for multipoint on-column detection. The FP sensor was fabricated by depositing a thin layer of metal and a layer of gas-sensitive polymer consecutively on the endface of an optical fiber, which formed the FP cavity. Light partially reflected from the metal layer and the polymer-air interface generated an interference spectrum, which shifted as the polymer layer absorbed the gas analyte. The FP sensor module was then assembled by inserting the FP sensor into a hole drilled in the wall of a fused-silica capillary, which can be easily connected to the conventional gas chromatography (GC) column through a universal quick seal column connector, thus enabling on-column real-time detection. We characterized the FP sensor module based microGC detector. Sensitive detection of various gas analytes was achieved with subnanogram detection limits. The rapid separation capability of the FP sensor module assembled with both single- and tandem-column systems was demonstrated, in which gas analytes having a wide range of polarities and volatilities were well-resolved. The tandem-column system obtained increased sensitivity and selectivity by employing two FP sensor modules coated with different polymers, showing great system versatility. PMID:20441156

  4. An experimental distribution of analog and digital information in a hybrid wireless visible light communication system based on acousto-optic modulation and sinusoidal gratings

    NASA Astrophysics Data System (ADS)

    Gómez Colín, R.; García Juárez, A.; Zaldívar Huerta, I. E.; Marquina, A. Vera; García Delgado, L. A.; Leal Cruz, A. L.; Gómez Fuentes, R.

    2016-03-01

    In this paper we propose a photonic architecture as an alternative tool to distribute point to multipoint analog and digital information over a hybrid wireless visible optical communication system. The experimental set-up is composed of a red laser pointer, an acousto-optic modulator, a sinusoidal grating and a photo-detector array. By using a simple and variable interferometric system, diffraction gratings with different spatial frequencies are generated and recorded on a photoemulsion which is composed of vanilla with dichromate gelatin. Analog video and digital information are first transmitted and recovered over a wireless communication system using a microwave carrier at 4.52 GHz which is generated by distributed feedback lasers operating in the low laser threshold current region. Separately, the recovered video information and digital data are combined with a radio frequency signal of 80 MHz, obtaining a subcarrier of information that is imposed on the optical carrier of the pointer laser using an acousto-optic modulator which is operated with an angle of incident light that satisfies the Bragg condition. The modulated optical carrier is sent to a sinusoidal grating, the diffraction pattern is photo-detected using an array of PIN photo-detectors. The use of sinusoidal gratings with acousto-optic modulators allows that number of channels to be increased when both components are placed in cascade.

  5. Clock distribution system for digital computers

    DOEpatents

    Wyman, Robert H.; Loomis, Jr., Herschel H.

    1981-01-01

    Apparatus for eliminating, in each clock distribution amplifier of a clock distribution system, sequential pulse catch-up error due to one pulse "overtaking" a prior clock pulse. The apparatus includes timing means to produce a periodic electromagnetic signal with a fundamental frequency having a fundamental frequency component V'.sub.01 (t); an array of N signal characteristic detector means, with detector means No. 1 receiving the timing means signal and producing a change-of-state signal V.sub.1 (t) in response to receipt of a signal above a predetermined threshold; N substantially identical filter means, one filter means being operatively associated with each detector means, for receiving the change-of-state signal V.sub.n (t) and producing a modified change-of-state signal V'.sub.n (t) (n=1, . . . , N) having a fundamental frequency component that is substantially proportional to V'.sub.01 (t-.theta..sub.n (t) with a cumulative phase shift .theta..sub.n (t) having a time derivative that may be made uniformly and arbitrarily small; and with the detector means n+1 (1.ltoreq.n

  6. Fault-tolerant power distribution system

    NASA Technical Reports Server (NTRS)

    Volp, Jeffrey A. (Inventor)

    1987-01-01

    A fault-tolerant power distribution system which includes a plurality of power sources and a plurality of nodes responsive thereto for supplying power to one or more loads associated with each node. Each node includes a plurality of switching circuits, each of which preferably uses a power field effect transistor which provides a diode operation when power is first applied to the nodes and which thereafter provides bi-directional current flow through the switching circuit in a manner such that a low voltage drop is produced in each direction. Each switching circuit includes circuitry for disabling the power field effect transistor when the current in the switching circuit exceeds a preselected value.

  7. The Hazards Data Distribution System update

    USGS Publications Warehouse

    Jones, Brenda K.; Lamb, Rynn M.

    2010-01-01

    After a major disaster, a satellite image or a collection of aerial photographs of the event is frequently the fastest, most effective way to determine its scope and severity. The U.S. Geological Survey (USGS) Emergency Operations Portal provides emergency first responders and support personnel with easy access to imagery and geospatial data, geospatial Web services, and a digital library focused on emergency operations. Imagery and geospatial data are accessed through the Hazards Data Distribution System (HDDS). HDDS historically provided data access and delivery services through nongraphical interfaces that allow emergency response personnel to select and obtain pre-event baseline data and (or) event/disaster response data. First responders are able to access full-resolution GeoTIFF images or JPEG images at medium- and low-quality compressions through ftp downloads. USGS HDDS home page: http://hdds.usgs.gov/hdds2/

  8. Multipoint Pressure and Temperature Sensing Fiber Optic Cable for Monitoring CO2 Sequestration

    SciTech Connect

    Challener, William

    2015-02-10

    This report describes the work completed on contract DE-FE0010116. The goal of this two year project was to develop and demonstrate in the laboratory a highly accurate multi-point pressure measurement fiber optic cable based on MEMS pressure sensors suitable for downhole deployment in a CO2 sequestration well. The sensor interrogator was also to be demonstrated in a remote monitoring system and environmental testing was to be completed to indicate its downhole survivability over a lengthy period of time (e.g., 20 years). An interrogator system based on a pulsed laser excitation was shown to be capable of multiple (potentially 100+) simultaneous sensor measurements. Two sensors packages were completed and spliced in a cable onto the same fiber and measured. One sensor package was subsequently measured at high temperatures and pressures in supercritical CO2, while the other package was measured prior and after being subjected to high torque stresses to mimic downhole deployment. The environmental and stress tests indicated areas in which the package design should be further improved.

  9. Upscaling Method Using Multipoint Geostatistics for Statistical Integration of Seismic and Electromagnetic Data

    NASA Astrophysics Data System (ADS)

    Lee, J.; Mukerji, T.; Tompkins, M. J.

    2012-12-01

    Joint integration of seismic and electromagnetic (EM) data has been studied to better characterize hydrocarbon reservoirs because they are sensitive to different reservoir properties. Most of them, however, applied deterministic joint inversion which provides the best estimate of the spatial distribution of reservoir properties in least square sense. Although this way of integrating two different data helps to obtain a more improved reservoir model matching both data, it gives only one reservoir model. But, numerous reservoirs can be consistent with seismic and EM data obtained from field measurements. Therefore, uncertainty associated with reservoir models should be quantified for reducing risks of making wrong decisions in reservoir management. We suggest statistical integration with a new upscaling scheme, which simulates the joint probability distribution of field scale seismic and EM data as well as reservoir properties, such as facies, porosity, and fluid saturation, not only to estimate reservoir properties but also to assess uncertainty of the estimates. Statistical data integration has been used (e.g., Lucet and Mavko, 1991; Avseth et al., 2001a, 2001b; Mukerji et al., 1998, 2001; Eidsvik et al., 2004) to characterize reservoirs from seismic attributes in geophysics. Main issue in applying statistical integration to joint seismic and EM data is the scale difference of two data because seismic (crosswell or surface seismic) and EM measurements (crosswell EM or CSEM) represent different volumes of a reservoir. In this research, geologically analogous reservoirs to the target reservoir were generated by unconstrained simulation with multipoint geostatistical algorithm, SNESIM (Strebelle, 2000, 2002). Well-log scale seismic and EM attributes were randomly assigned to the analogous reservoirs using conditional probability distributions of the attributes given facies obtained from well log analysis. Forward modeling and inversion of the analogous reservoirs were

  10. Alarm Management System for the D/3 Distributed Control System

    1997-03-19

    As industrial processes continue to grow in size and complexity, the Distrubuted Control Systems that automate and monitor these processes expand in a like manner. This increase in control system complexity has resulted in ever increasing numbers of alarms presented to the operator. The challenge for today's control system designer is to find innovative ways to present alarm information to the operator such that despite the large number of alarms, the operator is able tomore » quickly assess the status of the plant and immediately respond to the most critical alarms in a timely manner. This software package, designed and developed for the Savannah River Site Replacement High Level Waste Evaporator/Waste Removal Distributed Control System installed on the H-Area Tank Farm, provides an alarm system which utilizes the annunciator (SKID) panel as a means of statusing the plant and providing single keystroke access to the display on which an alarm resides.« less

  11. [Occupational exposure to sevoflurane in pediatric operating rooms: the multi-point sampling method for risk assessment].

    PubMed

    Zaffina, S; Camisa, V; Poscia, A; Tucci, M G; Montaldi, V; Cerabona, V; Wachocka, M; Moscato, U

    2012-01-01

    Several studies have shown that occupational exposure to anesthetic gases might be higher during pediatric surgery, probably due to the increased use of inhalational induction techniques. Our study aims to assess the level of exposure to sevoflurane in two rooms of pediatric surgery, using multi-point sampling method for environmental monitoring. The gas concentrations as well as its dispersion were measured in strategic points in the rooms for a total of 44 surgical interventions. Although the average of these concentrations has been rather low (1.32, SD +/- 1:55 ppm), the results obtained have documented a significant distribution kinetics difference inside the rooms as function of multiple factors among which there were the anesthetic technique used and the team involved. Therefore the method described allows to correctly analyze the spread of anesthetic gases and suggests a different risk stratification which may be dependent on the professional work.

  12. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2013-10-01 2013-10-01 false Grounded distribution systems (neutral grounded)....

  13. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2011-10-01 2011-10-01 false Grounded distribution systems (neutral grounded)....

  14. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2014-10-01 2014-10-01 false Grounded distribution systems (neutral grounded). 183... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems §...

  15. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor... 46 Shipping 1 2012-10-01 2012-10-01 false Electrical distribution systems. 28.855 Section...

  16. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor... 46 Shipping 1 2014-10-01 2014-10-01 false Electrical distribution systems. 28.855 Section...

  17. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2012-10-01 2012-10-01 false Grounded distribution systems (neutral grounded). 183... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems §...

  18. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor... 46 Shipping 1 2012-10-01 2012-10-01 false Electrical distribution systems. 28.360 Section...

  19. 47 CFR 73.626 - DTV distributed transmission systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false DTV distributed transmission systems. 73.626... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.626 DTV distributed transmission systems. (a... distributed transmission system (DTS). Except as expressly provided in this section, DTV stations operating...

  20. 47 CFR 73.626 - DTV distributed transmission systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false DTV distributed transmission systems. 73.626... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.626 DTV distributed transmission systems. (a... distributed transmission system (DTS). Except as expressly provided in this section, DTV stations operating...

  1. Fractional System Identification: An Approach Using Continuous Order-Distributions

    NASA Technical Reports Server (NTRS)

    Hartley, Tom T.; Lorenzo, Carl F.

    1999-01-01

    This paper discusses the identification of fractional- and integer-order systems using the concept of continuous order-distribution. Based on the ability to define systems using continuous order-distributions, it is shown that frequency domain system identification can be performed using least squares techniques after discretizing the order-distribution.

  2. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor... 46 Shipping 1 2010-10-01 2010-10-01 false Electrical distribution systems. 28.360 Section...

  3. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor... 46 Shipping 1 2010-10-01 2010-10-01 false Electrical distribution systems. 28.855 Section...

  4. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Electrical distribution systems. 28.855 Section 28.855... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or...

  5. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Electrical distribution systems. 28.360 Section 28.360... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or...

  6. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Electrical distribution systems. 28.855 Section 28.855... FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or...

  7. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Electrical distribution systems. 28.360 Section 28.360... Operate With More Than 16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or...

  8. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  9. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  10. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  11. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  12. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  13. Cathode power distribution system and method of using the same for power distribution

    DOEpatents

    Williamson, Mark A; Wiedmeyer, Stanley G; Koehl, Eugene R; Bailey, James L; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

    2014-11-11

    Embodiments include a cathode power distribution system and/or method of using the same for power distribution. The cathode power distribution system includes a plurality of cathode assemblies. Each cathode assembly of the plurality of cathode assemblies includes a plurality of cathode rods. The system also includes a plurality of bus bars configured to distribute current to each of the plurality of cathode assemblies. The plurality of bus bars include a first bus bar configured to distribute the current to first ends of the plurality of cathode assemblies and a second bus bar configured to distribute the current to second ends of the plurality of cathode assemblies.

  14. Characterizing and Improving Distributed Intrusion Detection Systems.

    SciTech Connect

    Hurd, Steven A; Proebstel, Elliot P.

    2007-11-01

    Due to ever-increasing quantities of information traversing networks, network administrators are developing greater reliance upon statistically sampled packet information as the source for their intrusion detection systems (IDS). Our research is aimed at understanding IDS performance when statistical packet sampling is used. Using the Snort IDS and a variety of data sets, we compared IDS results when an entire data set is used to the results when a statistically sampled subset of the data set is used. Generally speaking, IDS performance with statistically sampled information was shown to drop considerably even under fairly high sampling rates (such as 1:5). Characterizing and Improving Distributed Intrusion Detection Systems4AcknowledgementsThe authors wish to extend our gratitude to Matt Bishop and Chen-Nee Chuah of UC Davis for their guidance and support on this work. Our thanks are also extended to Jianning Mai of UC Davis and Tao Ye of Sprint Advanced Technology Labs for their generous assistance.We would also like to acknowledge our dataset sources, CRAWDAD and CAIDA, without which this work would not have been possible. Support for OC48 data collection is provided by DARPA, NSF, DHS, Cisco and CAIDA members.

  15. Distributed fiber optic fuel leak detection system

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Kempen, C.; Esterkin, Yan; Sun, Sunjian

    2013-05-01

    With the increase worldwide demand for hydrocarbon fuels and the vast development of new fuel production and delivery infrastructure installations around the world, there is a growing need for reliable fuel leak detection technologies to provide safety and reduce environmental risks. Hydrocarbon leaks (gas or liquid) pose an extreme danger and need to be detected very quickly to avoid potential disasters. Gas leaks have the greatest potential for causing damage due to the explosion risk from the dispersion of gas clouds. This paper describes progress towards the development of a fast response, high sensitivity, distributed fiber optic fuel leak detection (HySensTM) system based on the use of an optical fiber that uses a hydrocarbon sensitive fluorescent coating to detect the presence of fuel leaks present in close proximity along the length of the sensor fiber. The HySenseTM system operates in two modes, leak detection and leak localization, and will trigger an alarm within seconds of exposure contact. The fast and accurate response of the sensor provides reliable fluid leak detection for pipelines, tanks, airports, pumps, and valves to detect and minimize any potential catastrophic damage.

  16. Distributed fiber optic fuel leak detection system

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Kempen, C.; Esterkin, Yan; Sun, Sonjian

    2013-05-01

    With the increase worldwide demand for hydrocarbon fuels and the vast development of new fuel production and delivery infrastructure installations around the world, there is a growing need for reliable fuel leak detection technologies to provide safety and reduce environmental risks. Hydrocarbon leaks (gas or liquid) pose an extreme danger and need to be detected very quickly to avoid potential disasters. Gas leaks have the greatest potential for causing damage due to the explosion risk from the dispersion of gas clouds. This paper describes progress towards the development of a fast response, high sensitivity, distributed fiber optic fuel leak detection (HySenseTM) system based on the use of an optical fiber that uses a hydrocarbon sensitive fluorescent coating to detect the presence of fuel leaks present in close proximity along the length of the sensor fiber. The HySenseTM system operates in two modes, leak detection and leak localization, and will trigger an alarm within seconds of exposure contact. The fast and accurate response of the sensor provides reliable fluid leak detection for pipelines, tanks, airports, pumps, and valves to detect and minimize any potential catastrophic damage.

  17. Manganese deposition in drinking water distribution systems.

    PubMed

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

  18. Solar Cycle Variation and Multipoint Studies of ICME Properties

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    2005-01-01

    The goal of the Living With a Star program is to understand the Sun-Earth connection sufficiently well that we can solve problems critical to life and society. This can most effectively be done in the short term using observations from our past and on-going programs. Not only can this approach solve some of the pressing issues but also it can provide ideas for the deployment of future spacecraft in the LWS program. The proposed effort uses data from NEAR, SOHO, Wind, ACE and Pioneer Venus in quadrature, multipoint, and solar cycle studies to study the interplanetary coronal mass ejection and its role in the magnetic flux cycle of the Sun. ICMEs are most important to the LWS objectives because the solar wind conditions associated with these structures are the most geoeffective of any solar wind phenomena. Their ability to produce strong geomagnetic disturbances arises first because of their high speed. This high speed overtakes the ambient solar wind producing a bow shock wave similar to the terrestrial bow shock. In the new techniques we develop as part of this effort we exploit this feature of ICMEs. This shocked plasma has a greater velocity, higher density and stronger magnetic field than the ambient solar wind, conditions that can enhance geomagnetic activity. The driving ICME is a large magnetic structure expanding outward in the solar wind [Gosling, 19961. The ICMEs magnetic field is generally much higher than that in the ambient solar wind and the velocity is high. The twisted nature of the magnetic field in an ICME almost ensures that sometime during the ICME conditions favorable for geomagnetic storm initiation will occur.

  19. IDCDACS: IDC's Distributed Application Control System

    NASA Astrophysics Data System (ADS)

    Ertl, Martin; Boresch, Alexander; Kianička, Ján; Sudakov, Alexander; Tomuta, Elena

    2015-04-01

    The Preparatory Commission for the CTBTO is an international organization based in Vienna, Austria. Its mission is to establish a global verification regime to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which bans all nuclear explosions. For this purpose time series data from a global network of seismic, hydro-acoustic and infrasound (SHI) sensors are transmitted to the International Data Centre (IDC) in Vienna in near-real-time, where it is processed to locate events that may be nuclear explosions. We newly designed the distributed application control system that glues together the various components of the automatic waveform data processing system at the IDC (IDCDACS). Our highly-scalable solution preserves the existing architecture of the IDC processing system that proved successful over many years of operational use, but replaces proprietary components with open-source solutions and custom developed software. Existing code was refactored and extended to obtain a reusable software framework that is flexibly adaptable to different types of processing workflows. Automatic data processing is organized in series of self-contained processing steps, each series being referred to as a processing pipeline. Pipelines process data by time intervals, i.e. the time-series data received from monitoring stations is organized in segments based on the time when the data was recorded. So-called data monitor applications queue the data for processing in each pipeline based on specific conditions, e.g. data availability, elapsed time or completion states of preceding processing pipelines. IDCDACS consists of a configurable number of distributed monitoring and controlling processes, a message broker and a relational database. All processes communicate through message queues hosted on the message broker. Persistent state information is stored in the database. A configurable processing controller instantiates and monitors all data processing

  20. Suitability Evaluation of Multipoint Simultaneous CO2 Sampling Wireless Sensors for Livestock Buildings

    PubMed Central

    Calvet, Salvador; Campelo, José Carlos; Estellés, Fernando; Perles, Angel; Mercado, Ricardo; Serrano, Juan José

    2014-01-01

    The environment in livestock buildings must be controlled to ensure the health and welfare of both workers and animals, as well as to restrict the emission of pollutants to the atmosphere. Among the pollutants generated inside these premises, carbon dioxide (CO2) is of great interest in terms of animal welfare and ventilation control. The use of inexpensive sensors means that complete systems can be designed with a number of sensors located around the building. This paper describes a study of the suitability of multipoint simultaneous CO2 sensors operating in a wireless sensor network, which was found to operate satisfactorily under laboratory conditions and was found to be the best alternative for these applications. The sensors showed a highly linear response to CO2 concentrations, ranging from 500 to 5000 ppm. However, individual sensor response was found to differ, which made it necessary to calibrate each one separately. Sensor precision ranged between 80 and 110 ppm CO2, and sensor response to register a 95% change in concentration was estimated at around 5 min. These features mean this type of sensor network can be used to monitor animal welfare and also for environmental control in poorly ventilated livestock premises. According to the tests conducted in this study, a temporal drift may occur and therefore a regular calibration of sensors would be needed. PMID:24932867

  1. Suitability evaluation of multipoint simultaneous CO₂ sampling wireless sensors for livestock buildings.

    PubMed

    Calvet, Salvador; Campelo, José Carlos; Estellés, Fernando; Perles, Angel; Mercado, Ricardo; Serrano, Juan José

    2014-06-13

    The environment in livestock buildings must be controlled to ensure the health and welfare of both workers and animals, as well as to restrict the emission of pollutants to the atmosphere. Among the pollutants generated inside these premises, carbon dioxide (CO2) is of great interest in terms of animal welfare and ventilation control. The use of inexpensive sensors means that complete systems can be designed with a number of sensors located around the building. This paper describes a study of the suitability of multipoint simultaneous CO2 sensors operating in a wireless sensor network, which was found to operate satisfactorily under laboratory conditions and was found to be the best alternative for these applications. The sensors showed a highly linear response to CO2 concentrations, ranging from 500 to 5000 ppm. However, individual sensor response was found to differ, which made it necessary to calibrate each one separately. Sensor precision ranged between 80 and 110 ppm CO2, and sensor response to register a 95% change in concentration was estimated at around 5 min. These features mean this type of sensor network can be used to monitor animal welfare and also for environmental control in poorly ventilated livestock premises. According to the tests conducted in this study, a temporal drift may occur and therefore a regular calibration of sensors would be needed.

  2. A Self-Referencing Intensity-Based Fiber Optic Sensor with Multipoint Sensing Characteristics

    PubMed Central

    Choi, Sang-Jin; Kim, Young-Chon; Song, Minho; Pan, Jae-Kyung

    2014-01-01

    A self-referencing, intensity-based fiber optic sensor (FOS) is proposed and demonstrated. The theoretical analysis for the proposed design is given, and the validity of the theoretical analysis is confirmed via experiments. We define the measurement parameter, X, and the calibration factor, β, to find the transfer function, Hm,n, of the intensity-based FOS head. The self-referencing and multipoint sensing characteristics of the proposed system are validated by showing the measured Hm,n2 and relative error versus the optical power attenuation of the sensor head for four cases: optical source fluctuation, various remote sensing point distances, fiber Bragg gratings (FBGs) with different characteristics, and multiple sensor heads with cascade and/or parallel forms. The power-budget analysis and limitations of the measurement rates are discussed, and the measurement results of fiber-reinforced plastic (FRP) coupon strain using the proposed FOS are given as an actual measurement. The proposed FOS has several benefits, including a self-referencing characteristic, the flexibility to determine FBGs, and a simple structure in terms of the number of devices and measuring procedure. PMID:25046010

  3. A parallelized Python based Multi-Point Thomson Scattering analysis in NSTX-U

    NASA Astrophysics Data System (ADS)

    Miller, Jared; Diallo, Ahmed; Leblanc, Benoit

    2014-10-01

    Multi-Point Thomson Scattering (MPTS) is a reliable and accurate method of finding the temperature, density, and pressure of a magnetically confined plasma. Nd:YAG (1064 nm) lasers are fired into the plasma with a frequency of 60 Hz, and the light is Doppler shifted by Thomson scattering. Polychromators on the midplane of the tokamak pick up the light at various radii/scattering angles, and the avalanche photodiode's voltages are added to an MDSplus tree for later analysis. This project ports and optimizes the prior serial IDL MPTS code into a well-documented Python package that runs in parallel. Since there are 30 polychromators in the current NSTX setup (12 more will be added when NSTX-U is completed), using parallelism offers vast savings in performance. NumPy and SciPy further accelerate numerical calculations and matrix operations, Matplotlib and PyQt make an intuitive GUI with plots of the output, and Multiprocessing parallelizes the computationally intensive calculations. The Python package was designed with portability and flexibility in mind so it can be adapted for use in any polychromator-based MPTS system.

  4. Detection of contamination of municipal water distribution systems

    DOEpatents

    Cooper, John F.

    2012-01-17

    A system for the detection of contaminates of a fluid in a conduit. The conduit is part of a fluid distribution system. A chemical or biological sensor array is connected to the conduit. The sensor array produces an acoustic signal burst in the fluid upon detection of contaminates in the fluid. A supervisory control system connected to the fluid and operatively connected to the fluid distribution system signals the fluid distribution system upon detection of contaminates in the fluid.

  5. Systems analysis of the space shuttle. [communication systems, computer systems, and power distribution

    NASA Technical Reports Server (NTRS)

    Schilling, D. L.; Oh, S. J.; Thau, F.

    1975-01-01

    Developments in communications systems, computer systems, and power distribution systems for the space shuttle are described. The use of high speed delta modulation for bit rate compression in the transmission of television signals is discussed. Simultaneous Multiprocessor Organization, an approach to computer organization, is presented. Methods of computer simulation and automatic malfunction detection for the shuttle power distribution system are also described.

  6. Constrained Multipoint Aerodynamic Shape Optimization Using an Adjoint Formulation and Parallel Computers

    NASA Technical Reports Server (NTRS)

    Reuther, James; Jameson, Antony; Alonso, Juan Jose; Rimlinger, Mark J.; Saunders, David

    1997-01-01

    An aerodynamic shape optimization method that treats the design of complex aircraft configurations subject to high fidelity computational fluid dynamics (CFD), geometric constraints and multiple design points is described. The design process will be greatly accelerated through the use of both control theory and distributed memory computer architectures. Control theory is employed to derive the adjoint differential equations whose solution allows for the evaluation of design gradient information at a fraction of the computational cost required by previous design methods. The resulting problem is implemented on parallel distributed memory architectures using a domain decomposition approach, an optimized communication schedule, and the MPI (Message Passing Interface) standard for portability and efficiency. The final result achieves very rapid aerodynamic design based on a higher order CFD method. In order to facilitate the integration of these high fidelity CFD approaches into future multi-disciplinary optimization (NW) applications, new methods must be developed which are capable of simultaneously addressing complex geometries, multiple objective functions, and geometric design constraints. In our earlier studies, we coupled the adjoint based design formulations with unconstrained optimization algorithms and showed that the approach was effective for the aerodynamic design of airfoils, wings, wing-bodies, and complex aircraft configurations. In many of the results presented in these earlier works, geometric constraints were satisfied either by a projection into feasible space or by posing the design space parameterization such that it automatically satisfied constraints. Furthermore, with the exception of reference 9 where the second author initially explored the use of multipoint design in conjunction with adjoint formulations, our earlier works have focused on single point design efforts. Here we demonstrate that the same methodology may be extended to treat

  7. Energy Efficiency of Distributed Environmental Control Systems

    SciTech Connect

    Khalifa, H. Ezzat; Isik, Can; Dannenhoffer, John F. III

    2011-02-23

    In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control with a thermostat at each workstation. The thermal model shows that, un-optimized, DECS would lead to an increase in building energy consumption between 3-16% compared to the conventional approach depending on the climate regional and personal preferences of building occupants. Variations in building shape had little impact in the relative energy usage. 2. Development of a gradient-based optimization method to minimize energy consumption of DECS while keeping each occupant

  8. Distributed information system (water fact sheet)

    USGS Publications Warehouse

    Harbaugh, A.W.

    1986-01-01

    During 1982-85, the Water Resources Division (WRD) of the U.S. Geological Survey (USGS) installed over 70 large minicomputers in offices across the country to support its mission in the science of hydrology. These computers are connected by a communications network that allows information to be shared among computers in each office. The computers and network together are known as the Distributed Information System (DIS). The computers are accessed through the use of more than 1500 terminals and minicomputers. The WRD has three fundamentally different needs for computing: data management; hydrologic analysis; and administration. Data management accounts for 50% of the computational workload of WRD because hydrologic data are collected in all 50 states, Puerto Rico, and the Pacific trust territories. Hydrologic analysis consists of 40% of the computational workload of WRD. Cost accounting, payroll, personnel records, and planning for WRD programs occupies an estimated 10% of the computer workload. The DIS communications network is shown on a map. (Lantz-PTT)

  9. Distributed high-precision time transfer through passive optical networks

    NASA Astrophysics Data System (ADS)

    Wu, Guiling; Hu, Liang; Zhang, Hao; Chen, Jianping

    2014-09-01

    We propose a one-point to multipoint distributed time transfer through passive optical networks using a time division multiple access (TDMA) based two-way time transfer. The clock at each clock user node is, in turn, compared with the high-precision reference clock at a master node by a two-way time transfer during assigned subperiods. The corresponding TDMA control protocol and time transfer units for the proposed scheme are designed and implemented. A 1×8 experimental system with a 20 km single-mode fiber in each subpath is demonstrated. The results show that a standard deviation of <60 ps can be reached in each comparison subperiod.

  10. Current and potential distributions in corrosion systems

    SciTech Connect

    Smyrl, W.H.

    1980-01-01

    Current and potential distribution calculations in corrosion are reviewed. The mathematical methods used, and the specific results for galvanic corrosion, cathodic protection, and localized corrosion are described.

  11. Plasma distribution of cathodic ARC deposition system

    SciTech Connect

    Anders, S.; Raoux, S.; Krishnan, K.; MacGill, R.A.; Brown, I.G.

    1996-08-01

    The plasma distribution using a cathodic arc plasma source with and without magnetic macroparticle filter has been determined by depositing on a transparent plastic substrate and measuring the film absorption. It was found that the width of the distribution depends on the arc current, and it also depends on the cathode material which leads to a spatial separation of the elements when an alloy cathode is used. By applying a magnetic multicusp field near the exit of the magnetic filter, it was possible to modify the plasma distribution and obtain a flat plasma profile with a constant and homogeneous elemental distribution.

  12. Multi-point injection demonstration for solidification of shallow buried waste at Oak Ridge Reservation, Oak Ridge, Tennessee

    SciTech Connect

    1996-10-01

    The multi-point injection (MPI) technology is a precision, high-velocity jetting process for the in situ delivery of various agents to treat radiological and/or chemical wastes. A wide variety of waste forms can be treated, varying from heterogeneous waste dumped into shallow burial trenches to contaminated soils consisting of sands/gravels, silts/clays and soft rock. The robustness of the MPI system is linked to its broad range of applications which vary from in situ waste treatment to creation of both vertical and horizontal barriers. The only major constraint on the type of in situ treatment which can be delivered by the NTI system is that agents must be in a slurry form.

  13. Full Mesh Audio Conferencing Using the Point-to-Multipoint On-Board Switching Capability of ACTS

    NASA Technical Reports Server (NTRS)

    Rivett, Mary L.; Sethna, Zubin H.

    1996-01-01

    The purpose of this paper is to describe an implementation of audio conferencing using the ACTS T1-VSAT network. In particular, this implementation evaluates the use of the on-board switching capability of the satellite as a viable alternative for providing the multipoint connectivity normally provided by terrestrial audio bridge equipment The system that was implemented provides full mesh, full-duplex audio conferencing, with end-to-end voice paths between all participants requiring only a single hop (i.e. 250 msec. delay). Moreover, it addresses the lack of spontaneity in current systems by allowing a user to easily start a conference from any standard telephone handset connected to an ACTS earth station, and quickly add new members to the conference at any time using the 'hook flash' capability. No prior scheduling of resources is required and there is no central point of control, thereby providing the user with the spontaneity desired in audio conference control.

  14. An Intelligent System for Document Retrieval in Distributed Office Environments.

    ERIC Educational Resources Information Center

    Mukhopadhyay, Uttam; And Others

    1986-01-01

    MINDS (Multiple Intelligent Node Document Servers) is a distributed system of knowledge-based query engines for efficiently retrieving multimedia documents in an office environment of distributed workstations. By learning document distribution patterns and user interests and preferences during system usage, it customizes document retrievals for…

  15. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

  16. Distribution and the Free Enterprise System

    ERIC Educational Resources Information Center

    Wardlow, Erwin E.

    1975-01-01

    The author, president of the S. S. Kresge Company, advocates the opportunities and challenges of careers in retailing. Improving communications between the field of marketing and distributive education will be important in preparing future retailers or distribution managers for the constant change and intense competition of the business world. (EA)

  17. Distribution of Systemic Clarithromycin to Gingiva

    PubMed Central

    Burrell, Renita C.; Walters, John D.

    2008-01-01

    Background Aggressive and recurrent forms of periodontitis are associated with infections by Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Since these pathogens invade tissue, they are difficult to eliminate by root planing alone. Use of systemic antibiotics in conjunction with root planing significantly enhances clinical and microbiological treatment outcomes. While it is not widely prescribed by periodontists, clarithromycin is potentially useful because it is taken up by host cells and has favorable antimicrobial activity. Methods Experimental gingivitis was induced in eight healthy subjects at one randomly selected maxillary posterior site. The contralateral maxillary site served as the healthy control. Thereafter, subjects were administered 6 doses of 500 mg clarithromycin every 12 hours. Blood was then drawn and samples of gingiva were harvested from both sites. The samples were extracted and clarithromycin content was analyzed by liquid chromatography. Results Mean clarithromycin concentrations in healthy control and inflamed gingiva (2.4 μg/g and 3.0 μg/g, respectively) were significantly higher than in serum (0.5 μg/ml, P <0.05). Clarithromycin levels at control and gingivitis sites were higher than serum by 5.7 and 7.0-fold, respectively (difference between sites significant, P = 0.02). At control sites, a significant decrease in gingival crevicular fluid flow rate was evident at the conclusion of the clarithromycin regimen (P = 0.018). Conclusions Clarithromycin can attain higher levels in gingiva than serum and reaches higher levels in inflamed gingiva than in healthy gingiva. Its distribution profile appears to be suitable for treatment of periodontitis. The reduction in crevicular fluid flow at control sites suggests that clarithromycin may produce anti-inflammatory effects. PMID:18771373

  18. Simulation of Tasks Distribution in Horizontally Scalable Management System

    NASA Astrophysics Data System (ADS)

    Kustov, D.; Sherstneva, A.; Botygin, I.

    2016-08-01

    This paper presents an imitational model of the task distribution system for the components of territorially-distributed automated management system with a dynamically changing topology. Each resource of the distributed automated management system is represented with an agent, which allows to set behavior of every resource in the best possible way and ensure their interaction. The agent work load imitation was done via service query imitation formed in a system dynamics style using a stream diagram. The query generation took place in the abstract-represented center - afterwards, they were sent to the drive to be distributed to management system resources according to a ranking table.

  19. STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Presented within the report are cost data for construction and operation/maintenance of domestic water distribution and transmission pipelines, domestic water pumping stations, and domestic water storage reservoirs. To allow comparison of new construction with rehabilitation of e...

  20. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Water distribution systems. 3280....609 Water distribution systems. (a) Water supply—(1) Supply piping. Piping systems shall be sized to provide an adequate quantity of water to each plumbing fixture at a flow rate sufficient to keep...

  1. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Water distribution systems. 3280....609 Water distribution systems. Link to an amendment published at 78 FR 73986, Dec. 9, 2013. (a) Water supply—(1) Supply piping. Piping systems shall be sized to provide an adequate quantity of water to...

  2. Distributed expert systems for ground and space applications

    NASA Technical Reports Server (NTRS)

    Buckley, Brian; Wheatcraft, Louis

    1992-01-01

    Presented here is the Spacecraft Command Language (SCL) concept of the unification of ground and space operations using a distributed approach. SCL is a hybrid software environment borrowing from expert system technology, fifth generation language development, and multitasking operating system environments. Examples of potential uses for the system and current distributed applications of SCL are given.

  3. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must be... 46 Shipping 4 2011-10-01 2011-10-01 false Grounded distribution systems (Neutral grounded)....

  4. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must be... 46 Shipping 4 2012-10-01 2012-10-01 false Grounded distribution systems (Neutral grounded)....

  5. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must be... 46 Shipping 4 2014-10-01 2014-10-01 false Grounded distribution systems (Neutral grounded)....

  6. Distributed Impact Detector System (DIDS) Health Monitoring System Evaluation

    NASA Technical Reports Server (NTRS)

    Prosser, William H.; Madaras, Eric I.

    2010-01-01

    Damage due to impacts from micrometeoroids and orbital debris is one of the most significant on-orbit hazards for spacecraft. Impacts to thermal protection systems must be detected and the damage evaluated to determine if repairs are needed to allow safe re-entry. To address this issue for the International Space Station Program, Langley Research Center and Johnson Space Center technologists have been working to develop and implement advanced methods for detecting impacts and resultant leaks. LaRC funded a Small Business Innovative Research contract to Invocon, Inc. to develop special wireless sensor systems that are compact, light weight, and have long battery lifetimes to enable applications to long duration space structures. These sensor systems are known as distributed impact detection systems (DIDS). In an assessment, the NASA Engineering and Safety Center procured two prototype DIDS sensor units to evaluate their capabilities in laboratory testing and field testing in an ISS Node 1 structural test article. This document contains the findings of the assessment.

  7. Automation of the Athens (Tennessee) electric power distribution system

    SciTech Connect

    Rizy, D.T.; Stovall, J.P.; Usry, G.H.

    1988-01-01

    A large scale distribution automation research and development project has been conducted at the Athens Utilities Board (AUB) in Athens, Tennessee. The project goal was to experiment with the integrated monitoring and control of an entire distribution system from a central distribution control center. The project was sponsored by the U.S. Department of Energy, Office of Energy Storage and Distribution, Electric Energy Systems Program and managed by the Oak Ridge National Laboratory. The experience with the distribution substation monitoring and control, feeder monitoring, voltage and reactive power (vary) control, system (or circuit) reconfiguration for emergency and maintenance situations, and load control are described. A distribution automation applications software package for assessing system configuration, and volt/var control on automated radial distribution feeders was developed and is also described. 8 refs.

  8. Distributed photovoltaic generation in residential distribution systems: Impacts on power quality and anti-islanding

    NASA Astrophysics Data System (ADS)

    Mitra, Parag

    The past few decades have seen a consistent growth of distributed PV sources. Distributed PV, like other DG sources, can be located at or near load centers and provide benefits which traditional generation may lack. However, distribution systems were not designed to accommodate such power generation sources as these sources might lead to operational as well as power quality issues. A high penetration of distributed PV resources may lead to bi-directional power flow resulting in voltage swells, increased losses and overloading of conductors. Voltage unbalance is a concern in distribution systems and the effect of single-phase residential PV systems on voltage unbalance needs to be explored. Furthermore, the islanding of DGs presents a technical hurdle towards the seamless integration of DG sources with the electricity grid. The work done in this thesis explores two important aspects of grid inte-gration of distributed PV generation, namely, the impact on power quality and anti-islanding. A test distribution system, representing a realistic distribution feeder in Arizona is modeled to study both the aforementioned aspects. The im-pact of distributed PV on voltage profile, voltage unbalance and distribution sys-tem primary losses are studied using CYMDIST. Furthermore, a PSCAD model of the inverter with anti-island controls is developed and the efficacy of the anti-islanding techniques is studied. Based on the simulations, generalized conclusions are drawn and the problems/benefits are elucidated.

  9. On stability of difference schemes for hyperbolic multipoint NBVP with Neumann conditions

    NASA Astrophysics Data System (ADS)

    Yildirim, Ozgur; Uzun, Meltem

    2016-08-01

    In this work, a multipoint nonlocal boundary value problem (NBVP) for hyperbolic equations with Neumann conditions is considered. Third and fourth order of accuracy stable difference schemes for solving this problem are presented. Efficiency of these schemes are tested via MATLAB implementation.

  10. Multipoint alignment monitoring with amorphous silicon position detectors in a complex light path

    NASA Astrophysics Data System (ADS)

    Alberdi, J.; Arce, P.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Molinero, A.; Navarrete, J.; Oller, J. C.; Yuste, C.; Calderón, A.; Gómez, G.; González-Sánchez, F. J.; Martínez-Rivero, C.; Matorras, F.; Rodrigo, T.; Ruiz-Árbol, P.; Sobrón, M.; Vila, I.; Virto, A. L.

    2010-12-01

    This document presents an application of the new generation of amorphous silicon position detecting (ASPD) sensors to multipoint alignment. Twelve units are monitored along a 20 m long laser beam, where the light path is deflected by 90° using a pentaprism.

  11. Complete multipoint sib-pair analysis of qualitative and quantitative traits

    SciTech Connect

    Kruglyak, L.; Lander, E.S.

    1995-08-01

    Sib-pair analysis is an increasingly important tool for genetic dissection of complex traits. Current methods for sib-pair analysis are primarily based on studying individual genetic markers one at a time and thus fail to use the full inheritance information provided by multipoint linkage analysis. In this paper, we describe how to extract the complete multipoint inheritance information for each sib pair. We then describe methods that use this information to map loci affecting traits, thereby providing a unified approach to both qualitative and quantitative traits. Specifically, complete multipoint approaches are presented for (1) exclusion mapping of qualitative traits; (2) maximum-likelihood mapping of qualitative traits; (3) information-content mapping, showing the extent to which all inheritance information has been extracted at each location in the genome; and (4) quantitative-trait mapping, by two parametric methods and one nonparametric method. In addition, we explore the effects of marker density, marker polymorphism, and availability of parents on the information content of a study. We have implemented the analysis methods in a new computer package, MAPMAKER/SIBS. With this computer package, complete multipoint analysis with dozens of markers in hundreds of sib pairs can be carried out in minutes. 25 refs., 8 figs.

  12. The multipoint de la Vallee-Poussin problem for a convolution operator

    SciTech Connect

    Napalkov, Valentin V; Nuyatov, Andrey A

    2012-02-28

    Conditions are discovered which ensure that the space of entire functions can be represented as the sum of an ideal in the space of entire functions and the kernel of a convolution operator. In this way conditions for the multipoint de la Vallee-Poussin problem to have a solution are found. Bibliography: 14 titles.

  13. Multi-Point E-Conferencing with Initial Teacher Training Students in England: Pitfalls and Potential

    ERIC Educational Resources Information Center

    Pratt, Nick

    2008-01-01

    This article reports on attempts to initiate multi-point e-conferencing between English teacher education students on school placements, their host teachers and their university tutors. A sociocultural perspective is adopted in analysing the project, using the metaphor of a "professional knowledge landscape" [Clandinin, D. J., & Connelly, F. M.…

  14. Localization of the Krabbe disease gene (GALC) on chromosome 14 by multipoint linkage analysis

    SciTech Connect

    Oehlmann, R.; Wenger, D.A.; Knowlton, R.G. ); Zlotogora, J. )

    1993-12-01

    The gene responsible for Krabbe disease, an autosomal recessive disorder caused by deficiency of galactocerebrosidase (GALC), was localized by multipoint linkage analysis on chromosome 14. Eight mapped dinucleotide repeat polymorphisms were tested for linkage to GALC. Two-point linkage analysis demonstrated close linkage of GALC and D14S48, with [cflx [Zeta

  15. Multipoint laser Doppler vibrometry using holographic optical elements and a CMOS digital camera.

    PubMed

    Connelly, Michael J; Szecówka, Przemyslaw M; Jallapuram, Raghavendra; Martin, Suzanne; Toal, Vincent; Whelan, Maurice P

    2008-02-15

    A laser Doppler vibrometer (LDV) is described in which holographic optical elements are used to provide the interferometer reference and object illumination beams. A complementary metal-oxide semiconductor camera, incorporating a digital signal processor, is used to carry out real-time signal processing of the interferometer output to allow multipoint LDV to be implemented.

  16. Design note about a 75 KVA quiet power distribution system

    SciTech Connect

    Visser, A.T.

    1984-04-05

    This note describes a 75KVA quiet power distribution system for X 653 in neutrino Lab D. It is fed from the regular AC distribution which exists in the building and it has no standby power. Its purpose is to remove electrical disturbances which are present on the regular AC distribution.

  17. Managing Distributed Systems with Smart Subscriptions

    NASA Technical Reports Server (NTRS)

    Filman, Robert E.; Lee, Diana D.; Swanson, Keith (Technical Monitor)

    2000-01-01

    We describe an event-based, publish-and-subscribe mechanism based on using 'smart subscriptions' to recognize weakly-structured events. We present a hierarchy of subscription languages (propositional, predicate, temporal and agent) and algorithms for efficiently recognizing event matches. This mechanism has been applied to the management of distributed applications.

  18. Electrical power systems for distributed generation

    SciTech Connect

    Robertson, T.A.; Huval, S.J.

    1996-12-31

    {open_quotes}Distributed Generation{close_quotes} has become the {open_quotes}buzz{close_quotes} word of an electric utility industry facing deregulation. Many industrial facilities utilize equipment in distributed installations to serve the needs of a thermal host through the capture of exhaust energy in a heat recovery steam generator. The electrical power generated is then sold as a {open_quotes}side benefit{close_quotes} to the cost-effective supply of high quality thermal energy. Distributed generation is desirable for many different reasons, each with unique characteristics of the product. Many years of experience in the distributed generation market has helped Stewart & Stevenson to define a range of product features that are crucial to most any application. The following paper will highlight a few of these applications. The paper will also examine the range of products currently available and in development. Finally, we will survey the additional services offered by Stewart & Stevenson to meet the needs of a rapidly changing power generation industry.

  19. SLC Interferometer System and Phase Distribution Upgrades

    SciTech Connect

    Akre, Ron; /SLAC

    2011-08-26

    Many of the components used in the Stanford Linear Collider (SLC) phasing system date back 30 years to the construction of SLAC. At the start of SLC the phase reference system was upgraded with many of the original components remaining. The R.F. drive system phase stability requirements became tighter with operation and optimization of the SLC. This paper describes analysis done on the R.F. drive system and interferometer system during the 1996 run and down time, modifications to the systems during the 1996-97 down time, and the improvements in stability from the modifications.

  20. An improved AVC strategy applied in distributed wind power system

    NASA Astrophysics Data System (ADS)

    Zhao, Y. N.; Liu, Q. H.; Song, S. Y.; Mao, W.

    2016-08-01

    Traditional AVC strategy is mainly used in wind farm and only concerns about grid connection point, which is not suitable for distributed wind power system. Therefore, this paper comes up with an improved AVC strategy applied in distributed wind power system. The strategy takes all nodes of distribution network into consideration and chooses the node having the most serious voltage deviation as control point to calculate the reactive power reference. In addition, distribution principles can be divided into two conditions: when wind generators access to network on single node, the reactive power reference is distributed according to reactive power capacity; when wind generators access to network on multi-node, the reference is distributed according to sensitivity. Simulation results show the correctness and reliability of the strategy. Compared with traditional control strategy, the strategy described in this paper can make full use of generators reactive power output ability according to the distribution network voltage condition and improve the distribution network voltage level effectively.

  1. Long-Tailed Distributions in Biological Systems:. Revisit to Lognormals

    NASA Astrophysics Data System (ADS)

    Kobayashi, N.; Kohyama, K.; Moriyama, O.; Sasaki, Y.; Matsushita, M.; Matsushita, S.

    2007-07-01

    Long-tailed distributions in biological systems have been studied. First, we found that lognormal distributions show excellent fit with various data for the duration distribution of disability in aged people, irrespective of their severity and gender. The robust lognormal distribution of disability implies that the incidence of diseases can be completed by many independent subprocesses in succession. Next, we studied food fragmentation by human mastication. A lognormal distribution well fits to the entire region for masticated food fragments for a small number of chewing strokes. Furthermore, the tail of the fragment-size distribution changes from the lognormal distribution to a power-law one as the chewing stroke number increases. The good data fitting by the lognormal and power-law distribution implies that two functions of mastication, a sequential fragmentation with cascade and randomness and a lower threshold for fragment size, may affect the size distribution of masticated food fragments.

  2. FIPA agent based network distributed control system

    SciTech Connect

    D. Abbott; V. Gyurjyan; G. Heyes; E. Jastrzembski; C. Timmer; E. Wolin

    2003-03-01

    A control system with the capabilities to combine heterogeneous control systems or processes into a uniform homogeneous environment is discussed. This dynamically extensible system is an example of the software system at the agent level of abstraction. This level of abstraction considers agents as atomic entities that communicate to implement the functionality of the control system. Agents' engineering aspects are addressed by adopting the domain independent software standard, formulated by FIPA. Jade core Java classes are used as a FIPA specification implementation. A special, lightweight, XML RDFS based, control oriented, ontology markup language is developed to standardize the description of the arbitrary control system data processor. Control processes, described in this language, are integrated into the global system at runtime, without actual programming. Fault tolerance and recovery issues are also addressed.

  3. Distribution system reliability assessment using hierarchical Markov modeling

    SciTech Connect

    Brown, R.E.; Gupta, S.; Christie, R.D.; Venkata, S.S.; Fletcher, R.

    1996-10-01

    Distribution system reliability assessment is concerned with power availability and power quality at each customer`s service entrance. This paper presents a new method, termed Hierarchical Markov Modeling (HMM), which can perform predictive distribution system reliability assessment. HMM is unique in that it decomposes the reliability model based on system topology, integrated protection systems, and individual protection devices. This structure, which easily accommodates the effects of backup protection, fault isolation, and load restoration, is compared to simpler reliability models. HMM is then used to assess the reliability of an existing utility distribution system and to explore the reliability impact of several design improvement options.

  4. Space Station Freedom power management and distribution system design

    NASA Technical Reports Server (NTRS)

    Teren, Fred

    1989-01-01

    The design is described of the Space Station Freedom Power Management and Distribution (PMAD) System. In addition, the significant trade studies which were conducted are described, which led to the current PMAD system configuration.

  5. Distributed Space System Technology Demonstrations with the Emerald Nanosatellite

    NASA Technical Reports Server (NTRS)

    Twiggs, Robert

    2002-01-01

    A viewgraph presentation of Distributed Space System Technologies utilizing the Emerald Nanosatellite is shown. The topics include: 1) Structure Assembly; 2) Emerald Mission; 3) Payload and Mission Operations; 4) System and Subsystem Description; and 5) Safety Integration and Testing.

  6. A support architecture for reliable distributed computing systems

    NASA Technical Reports Server (NTRS)

    Dasgupta, Partha; Leblanc, Richard J., Jr.

    1988-01-01

    The Clouds project is well underway to its goal of building a unified distributed operating system supporting the object model. The operating system design uses the object concept of structuring software at all levels of the system. The basic operating system was developed and work is under progress to build a usable system.

  7. Micro-Avionics Node for Distributed Avionics System

    NASA Technical Reports Server (NTRS)

    Blaes, B. R.

    2001-01-01

    An avionics system is a platform residing on a flight vehicle that provides the resources (hardware and software) needed to manage the flight mission. Distributing the avionics system components, both functionally and spatially, can provide characteristics that benefit the overall system robustness, reliability, testability, and maintainability. This abstract discusses the concept of a distributed avionics system consisting of a network of micro-avionics nodes. Additional information is contained in the original extended abstract.

  8. Modeling the Delivery Physiology of Distributed Learning Systems.

    ERIC Educational Resources Information Center

    Paquette, Gilbert; Rosca, Ioan

    2003-01-01

    Discusses instructional delivery models and their physiology in distributed learning systems. Highlights include building delivery models; types of delivery models, including distributed classroom, self-training on the Web, online training, communities of practice, and performance support systems; and actors (users) involved, including experts,…

  9. GROWTH OF HETROTROPHIC BIOFILMS IN A WATER DISTRIBUTION SYSTEM SIMULATOR

    EPA Science Inventory

    The U.S. EPA has designed and constructed a distribution system simulator (DSS) to evaluate factors which influence water quality within water distribution systems. Six individual 25 meter lengths of 15 cm diameter ductile iron pipe are arranged into loop configurations. Each lo...

  10. Analysis Model for Domestic Hot Water Distribution Systems: Preprint

    SciTech Connect

    Maguire, J.; Krarti, M.; Fang, X.

    2011-11-01

    A thermal model was developed to estimate the energy losses from prototypical domestic hot water (DHW) distribution systems for homes. The developed model, using the TRNSYS simulation software, allows researchers and designers to better evaluate the performance of hot water distribution systems in homes. Modeling results were compared with past experimental study results and showed good agreement.

  11. 49 CFR 192.747 - Valve maintenance: Distribution systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Valve maintenance: Distribution systems. 192.747... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.747 Valve maintenance: Distribution systems. (a) Each valve, the use of which may be necessary for the safe operation...

  12. 49 CFR 192.747 - Valve maintenance: Distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Valve maintenance: Distribution systems. 192.747... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.747 Valve maintenance: Distribution systems. (a) Each valve, the use of which may be necessary for the safe operation...

  13. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... generator to ground before the generator is connected to the bus, except the neutral of an emergency...

  14. 47 CFR 73.626 - DTV distributed transmission systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false DTV distributed transmission systems. 73.626 Section 73.626 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.626 DTV distributed transmission systems....

  15. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oxygen distribution system. 23.1445 Section... Equipment § 23.1445 Oxygen distribution system. Link to an amendment published at 76 FR 75762, December 2, 2011. (a) Except for flexible lines from oxygen outlets to the dispensing units, or where shown to...

  16. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oxygen distribution system. 23.1445 Section... Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the... used for any oxygen line that is normally pressurized during flight. (b) Nonmetallic...

  17. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Oxygen distribution system. 23.1445 Section... Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the... used for any oxygen line that is normally pressurized during flight. (b) Nonmetallic...

  18. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oxygen distribution system. 23.1445 Section... Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the... used for any oxygen line that is normally pressurized during flight. (b) Nonmetallic...

  19. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oxygen distribution system. 23.1445 Section... Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the... used for any oxygen line that is normally pressurized during flight. (b) Nonmetallic...

  20. Battery management system with distributed wireless sensors

    DOEpatents

    Farmer, Joseph C.; Bandhauer, Todd M.

    2016-02-23

    A system for monitoring parameters of an energy storage system having a multiplicity of individual energy storage cells. A radio frequency identification and sensor unit is connected to each of the individual energy storage cells. The radio frequency identification and sensor unit operates to sense the parameter of each individual energy storage cell and provides radio frequency transmission of the parameters of each individual energy storage cell. A management system monitors the radio frequency transmissions from the radio frequency identification and sensor units for monitoring the parameters of the energy storage system.

  1. LSI-based amperometric sensor for bio-imaging and multi-point biosensing.

    PubMed

    Inoue, Kumi Y; Matsudaira, Masahki; Kubo, Reyushi; Nakano, Masanori; Yoshida, Shinya; Matsuzaki, Sakae; Suda, Atsushi; Kunikata, Ryota; Kimura, Tatsuo; Tsurumi, Ryota; Shioya, Toshihito; Ino, Kosuke; Shiku, Hitoshi; Satoh, Shiro; Esashi, Masayoshi; Matsue, Tomokazu

    2012-09-21

    We have developed an LSI-based amperometric sensor called "Bio-LSI" with 400 measurement points as a platform for electrochemical bio-imaging and multi-point biosensing. The system is comprised of a 10.4 mm × 10.4 mm CMOS sensor chip with 20 × 20 unit cells, an external circuit box, a control unit for data acquisition, and a DC power box. Each unit cell of the chip contains an operational amplifier with a switched-capacitor type I-V converter for in-pixel signal amplification. We successfully realized a wide dynamic range from ±1 pA to ±100 nA with a well-organized circuit design and operating software. In particular, in-pixel signal amplification and an original program to control the signal read-out contribute to the lower detection limit and wide detection range of Bio-LSI. The spacial resolution is 250 μm and the temporal resolution is 18-125 ms/400 points, which depends on the desired current detection range. The coefficient of variance of the current for 400 points is within 5%. We also demonstrated the real-time imaging of a biological molecule using Bio-LSI. The LSI coated with an Os-HRP film was successfully applied to the monitoring of the changes of hydrogen peroxide concentration in a flow. The Os-HRP-coated LSI was spotted with glucose oxidase and used for bioelectrochemical imaging of the glucose oxidase (GOx)-catalyzed oxidation of glucose. Bio-LSI is a promising platform for a wide range of analytical fields, including diagnostics, environmental measurements and basic biochemistry. PMID:22847217

  2. Intracavity Rayleigh/Mie Scattering for Multipoint, Two-Component Velocity Measurement

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Lee, Joseph W.

    2006-01-01

    A simultaneous multi-point two-component Doppler velocimeter is described. The system uses two optical cavities: a Fabry-Perot etalon and an optical cavity for collecting and re-circulating the Rayleigh/Mie scattered light that is collected from the measurement volume in two parallel, but opposite directions. Single-pulse measurements of two orthogonal components of the velocity vector in a supersonic free jet were performed to demonstrate the technique. The re-circulation of the light rejected by the interferometer input mirror also increased the signal intensity by a factor of 3.5. 2005 Optical Society of America Interferometric Rayleigh scattering has previously been used for single-point velocity measurements in unseeded gas flow. However, this past work has generally been limited to probing with continuous-wave lasers resulting in time-averaged measurements of velocity. Multiple velocity components have been measured simultaneously by separate instruments.1,2 It has also been demonstrated that two orthogonal velocity components can be measured simultaneously at one point using one interferometer by reflecting back the probing laser beam, although this approach results in directional ambiguity of the flow velocity vector.3 This measurement ambiguity was removed by prior knowledge of the approximate magnitude and sign of the velocity components. Furthermore, it was shown that multiple points could be measured simultaneously with a Rayleigh scattering interferometric approach, but only one component of velocity was measured.4 Another method of performing multiple component velocity measurements with Rayleigh scattering uses a pair of cameras to image the flow, one of which views the flow through an iodine gas filter. This iodine-filter technique has the advantage of allowing high-resolution velocity imaging, but it generally has a lower dynamic range.

  3. Interfaces for Distributed Systems of Information Servers.

    ERIC Educational Resources Information Center

    Kahle, Brewster; And Others

    1992-01-01

    Describes two systems--Wide Area Information Servers (WAIS) and Rosebud--that provide protocol-based mechanisms for accessing remote full-text information servers. Design constraints, human interface design, and implementation are examined for five interfaces to these systems developed to run on the Macintosh or Unix terminals. Sample screen…

  4. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., and each control and protective device. (b) If two independent sources of electrical power for particular equipment or systems are required by this chapter, in the event of the failure of one power source for such equipment or system, another power source (including its separate feeder) must be...

  5. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., and each control and protective device. (b) If two independent sources of electrical power for particular equipment or systems are required by this chapter, in the event of the failure of one power source for such equipment or system, another power source (including its separate feeder) must be...

  6. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., and each control and protective device. (b) (c) If two independent sources of electrical power for particular equipment or systems are required by this chapter, in the event of the failure of one power source for such equipment or system, another power source (including its separate feeder) must...

  7. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., and each control and protective device. (b) (c) If two independent sources of electrical power for particular equipment or systems are required by this chapter, in the event of the failure of one power source for such equipment or system, another power source (including its separate feeder) must...

  8. A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

    NASA Astrophysics Data System (ADS)

    Akinbode, Oluwaseyi Wemimo

    The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load

  9. Voltage Control in Distribution Systems Considered Reactive Power Output Sharing

    NASA Astrophysics Data System (ADS)

    Oshiro, Masato; Senjyu, Tomonobu; Yona, Atsushi; Urasaki, Naomitsu; Funabashi, Toshihisa

    In recent years, distributed generation (DG) and renewable energy source (RES) are attracting special attention to distribution systems. Renewable energy such as photovoltaic (PV) system and wind turbine generator are used as a source of clean energy. However, the large amount of distributed generation causes voltage deviation beyond a statutory range in distribution systems. This paper proposes a methodology for voltage control by using inverters interfaced with DG and tap changing transformers. In the proposed method a one-day schedule of voltage references for the control devices are determined by an optimization technique based on predicted values of load demand and PV power generation. Furthermore, decided reactive power output according to the locally measurable voltage based on droop characteristic. Slope and base value on droop characteristic are selected by fuzzy control. The proposed method accomplishes improvement against voltage distribution considered the reactive power output sharing and reduction of distribution loss. The effectiveness of the proposed method is verified by using MATLAB®.

  10. Architecture of a distributed multimission operations system

    NASA Technical Reports Server (NTRS)

    Yamada, Takahiro

    1994-01-01

    This paper presents an architecture to develop a multimission operations systems, which we call DIOSA. In this architecture, a component used as a building block is called a functional block. Each functional block has a standard structure, and the interface between functional blocks are defined with a set of standard protocols. This paper shows the structure of the database used by functional blocks, the structure of interfaces between functional blocks, and the structure of system management. Finally, examples of typical functional blocks and an example of a system constructed with this architecture is shown.

  11. Testing Distributed ABS System with Fault Injection

    NASA Astrophysics Data System (ADS)

    Trawczyński, Dawid; Sosnowski, Janusz; Gawkowski, Piotr

    The paper deals with the problem of adapting software implemented fault injection technique (SWIFI) to evaluate dependability of reactive microcontroller systems. We present an original methodology of disturbing controller operation and analyzing fault effects taking into account reactions of the controlled object and the impact of the system environment. Faults can be injected randomly (in space and time) or targeted at the most sensitive elements of the controller to check it at high stresses. This approach allows identifying rarely encountered problems, usually missed in classical approaches. The developed methodology has been used successfully to verify dependability of ABS system. Experimental results are commented in the paper.

  12. Design of software for distributed/multiprocessor systems

    SciTech Connect

    Mckelvey, T.R.; Agrawal, D.P.

    1982-01-01

    Software design methodologies for distributed/multiprocessor systems are investigated. Parallelism and multitasking are considered as key issues in the design process. Petri-Nets and precedence graphs are presented as techniques for the modeling of a problem for implementation on a computer system. Techniques using the Petri-Net and precedence graph to decompose the problem model into subsets that may be executed on a distributed/multiprocessor system are presented. These techniques offer a systematic design methodology for the design of distributed/multiprocessor system software. 8 references.

  13. One approach for evaluating the Distributed Computing Design System (DCDS)

    NASA Technical Reports Server (NTRS)

    Ellis, J. T.

    1985-01-01

    The Distributed Computer Design System (DCDS) provides an integrated environment to support the life cycle of developing real-time distributed computing systems. The primary focus of DCDS is to significantly increase system reliability and software development productivity, and to minimize schedule and cost risk. DCDS consists of integrated methodologies, languages, and tools to support the life cycle of developing distributed software and systems. Smooth and well-defined transistions from phase to phase, language to language, and tool to tool provide a unique and unified environment. An approach to evaluating DCDS highlights its benefits.

  14. A distributed expert system for fault diagnosis

    SciTech Connect

    Cardozo, E.; Talukdar, S.N.

    1988-05-01

    This paper describes a hybrid approach to synthesizing solutions for diagnosis and set covering problems from the area of power system operations. The approach combines expert systems written in a rule-based language (OPS5) with algorithmic programs written in C and Lisp. An environment called DPSK has been developed to allow these programs to be run in parallel in a network of computers. Speeds sufficient for real-time applications can thereby be obtained.

  15. Distributed Sensor Coordination for Advanced Energy Systems

    SciTech Connect

    Tumer, Kagan

    2013-07-31

    The ability to collect key system level information is critical to the safe, efficient and reli- able operation of advanced energy systems. With recent advances in sensor development, it is now possible to push some level of decision making directly to computationally sophisticated sensors, rather than wait for data to arrive to a massive centralized location before a decision is made. This type of approach relies on networked sensors (called “agents” from here on) to actively collect and process data, and provide key control deci- sions to significantly improve both the quality/relevance of the collected data and the as- sociating decision making. The technological bottlenecks for such sensor networks stem from a lack of mathematics and algorithms to manage the systems, rather than difficulties associated with building and deploying them. Indeed, traditional sensor coordination strategies do not provide adequate solutions for this problem. Passive data collection methods (e.g., large sensor webs) can scale to large systems, but are generally not suited to highly dynamic environments, such as ad- vanced energy systems, where crucial decisions may need to be reached quickly and lo- cally. Approaches based on local decisions on the other hand cannot guarantee that each agent performing its task (maximize an agent objective) will lead to good network wide solution (maximize a network objective) without invoking cumbersome coordination rou- tines. There is currently a lack of algorithms that will enable self-organization and blend the efficiency of local decision making with the system level guarantees of global decision making, particularly when the systems operate in dynamic and stochastic environments. In this work we addressed this critical gap and provided a comprehensive solution to the problem of sensor coordination to ensure the safe, reliable, and robust operation of advanced energy systems. The differentiating aspect of the proposed work is in shift- ing

  16. A comparison of queueing, cluster and distributed computing systems

    NASA Technical Reports Server (NTRS)

    Kaplan, Joseph A.; Nelson, Michael L.

    1993-01-01

    Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in their design philosophy and implementation. Based on published reports on the different systems and conversations with the system's developers and vendors, a comparison of the systems are made on the integral issues of clustered computing.

  17. Automation of Space Station module power management and distribution system

    NASA Technical Reports Server (NTRS)

    Bechtel, Robert; Weeks, Dave; Walls, Bryan

    1990-01-01

    Viewgraphs on automation of space station module (SSM) power management and distribution (PMAD) system are presented. Topics covered include: reasons for power system automation; SSM/PMAD approach to automation; SSM/PMAD test bed; SSM/PMAD topology; functional partitioning; SSM/PMAD control; rack level autonomy; FRAMES AI system; and future technology needs for power system automation.

  18. Integrating security in a group oriented distributed system

    NASA Technical Reports Server (NTRS)

    Reiter, Michael; Birman, Kenneth; Gong, LI

    1992-01-01

    A distributed security architecture is proposed for incorporation into group oriented distributed systems, and in particular, into the Isis distributed programming toolkit. The primary goal of the architecture is to make common group oriented abstractions robust in hostile settings, in order to facilitate the construction of high performance distributed applications that can tolerate both component failures and malicious attacks. These abstractions include process groups and causal group multicast. Moreover, a delegation and access control scheme is proposed for use in group oriented systems. The focus is the security architecture; particular cryptosystems and key exchange protocols are not emphasized.

  19. Distributed Generators Allocation in Radial Distribution Systems with Load Growth using Loss Sensitivity Approach

    NASA Astrophysics Data System (ADS)

    Kumar, Ashwani; Vijay Babu, P.; Murty, V. V. S. N.

    2016-07-01

    Rapidly increasing electricity demands and capacity shortage of transmission and distribution facilities are the main driving forces for the growth of distributed generation (DG) integration in power grids. One of the reasons for choosing a DG is its ability to support voltage in a distribution system. Selection of effective DG characteristics and DG parameters is a significant concern of distribution system planners to obtain maximum potential benefits from the DG unit. The objective of the paper is to reduce the power losses and improve the voltage profile of the radial distribution system with optimal allocation of the multiple DG in the system. The main contribution in this paper is (i) combined power loss sensitivity (CPLS) based method for multiple DG locations, (ii) determination of optimal sizes for multiple DG units at unity and lagging power factor, (iii) impact of DG installed at optimal, that is, combined load power factor on the system performance, (iv) impact of load growth on optimal DG planning, (v) Impact of DG integration in distribution systems on voltage stability index, (vi) Economic and technical Impact of DG integration in the distribution systems. The load growth factor has been considered in the study which is essential for planning and expansion of the existing systems. The technical and economic aspects are investigated in terms of improvement in voltage profile, reduction in total power losses, cost of energy loss, cost of power obtained from DG, cost of power intake from the substation, and savings in cost of energy loss. The results are obtained on IEEE 69-bus radial distribution systems and also compared with other existing methods.

  20. Distributed sensor coordination for advanced energy systems

    SciTech Connect

    Tumer, Kagan

    2015-03-12

    Motivation: The ability to collect key system level information is critical to the safe, efficient and reliable operation of advanced power systems. Recent advances in sensor technology have enabled some level of decision making directly at the sensor level. However, coordinating large numbers of sensors, particularly heterogeneous sensors, to achieve system level objectives such as predicting plant efficiency, reducing downtime or predicting outages requires sophisticated coordination algorithms. Indeed, a critical issue in such systems is how to ensure the interaction of a large number of heterogenous system components do not interfere with one another and lead to undesirable behavior. Objectives and Contributions: The long-term objective of this work is to provide sensor deployment, coordination and networking algorithms for large numbers of sensors to ensure the safe, reliable, and robust operation of advanced energy systems. Our two specific objectives are to: 1. Derive sensor performance metrics for heterogeneous sensor networks. 2. Demonstrate effectiveness, scalability and reconfigurability of heterogeneous sensor network in advanced power systems. The key technical contribution of this work is to push the coordination step to the design of the objective functions of the sensors, allowing networks of heterogeneous sensors to be controlled. By ensuring that the control and coordination is not specific to particular sensor hardware, this approach enables the design and operation of large heterogeneous sensor networks. In addition to the coordination coordination mechanism, this approach allows the system to be reconfigured in response to changing needs (e.g., sudden external events requiring new responses) or changing sensor network characteristics (e.g., sudden changes to plant condition). Impact: The impact of this work extends to a large class of problems relevant to the National Energy Technology Laboratory including sensor placement, heterogeneous sensor

  1. Performance Enhancement of Radial Distributed System with Distributed Generators by Reconfiguration Using Binary Firefly Algorithm

    NASA Astrophysics Data System (ADS)

    Rajalakshmi, N.; Padma Subramanian, D.; Thamizhavel, K.

    2015-03-01

    The extent of real power loss and voltage deviation associated with overloaded feeders in radial distribution system can be reduced by reconfiguration. Reconfiguration is normally achieved by changing the open/closed state of tie/sectionalizing switches. Finding optimal switch combination is a complicated problem as there are many switching combinations possible in a distribution system. Hence optimization techniques are finding greater importance in reducing the complexity of reconfiguration problem. This paper presents the application of firefly algorithm (FA) for optimal reconfiguration of radial distribution system with distributed generators (DG). The algorithm is tested on IEEE 33 bus system installed with DGs and the results are compared with binary genetic algorithm. It is found that binary FA is more effective than binary genetic algorithm in achieving real power loss reduction and improving voltage profile and hence enhancing the performance of radial distribution system. Results are found to be optimum when DGs are added to the test system, which proved the impact of DGs on distribution system.

  2. Distributed and recoverable digital control system

    NASA Technical Reports Server (NTRS)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2010-01-01

    A real-time multi-tasking digital control system with rapid recovery capability is disclosed. The control system includes a plurality of computing units comprising a plurality of redundant processing units, with each of the processing units configured to generate one or more redundant control commands. One or more internal monitors are employed for detecting data errors in the control commands. One or more recovery triggers are provided for initiating rapid recovery of a processing unit if data errors are detected. The control system also includes a plurality of actuator control units each in operative communication with the computing units. The actuator control units are configured to initiate a rapid recovery if data errors are detected in one or more of the processing units. A plurality of smart actuators communicates with the actuator control units, and a plurality of redundant sensors communicates with the computing units.

  3. An implementation of the distributed programming structural synthesis system (PROSSS)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L., Jr.

    1981-01-01

    A method is described for implementing a flexible software system that combines large, complex programs with small, user-supplied, problem-dependent programs and that distributes their execution between a mainframe and a minicomputer. The Programming Structural Synthesis System (PROSSS) was the specific software system considered. The results of such distributed implementation are flexibility of the optimization procedure organization and versatility of the formulation of constraints and design variables.

  4. Communications and Tracking Distributed Systems Evolution Study

    NASA Technical Reports Server (NTRS)

    Culpepper, William

    1990-01-01

    The Communications and Tracking (C & T) techniques and equipment to support evolutionary space station concepts are being analyzed. Evolutionary space station configurations and operational concepts are used to derive the results to date. A description of the C & T system based on future capability needs is presented. Included are the hooks and scars currently identified to support future growth.

  5. Distributed Timing and Triggering Control System

    SciTech Connect

    Bowen, T., Huerta, J. A.

    2012-08-01

    This document is a slide show type presentation regarding the need and realization of a new control system for work at the Nevada National Security Site. Commercial products that met the need are identified, both hardware and software. Particular emphasis is on the Integrated Signal Programmer.

  6. TIME DELAY SYSTEMS WITH DISTRIBUTION DEPENDENT DYNAMICS

    PubMed Central

    Banks, H. T.; Dediu, Sava; Nguyen, Hoan K.

    2009-01-01

    General delay dynamical systems in which uncertainty is present in the form of probability measure dependent dynamics are considered. Several motivating examples arising in biology are discussed. A functional analytic framework for investigating well–posedness (existence, uniqueness and continuous dependence of solutions), inverse problems, sensitivity analysis and approximations of the measures for computational purposes is surveyed. PMID:19865602

  7. TIME DELAY SYSTEMS WITH DISTRIBUTION DEPENDENT DYNAMICS.

    PubMed

    Banks, H T; Dediu, Sava; Nguyen, Hoan K

    2007-01-01

    General delay dynamical systems in which uncertainty is present in the form of probability measure dependent dynamics are considered. Several motivating examples arising in biology are discussed. A functional analytic framework for investigating well-posedness (existence, uniqueness and continuous dependence of solutions), inverse problems, sensitivity analysis and approximations of the measures for computational purposes is surveyed.

  8. Residential hot water distribution systems: Roundtablesession

    SciTech Connect

    Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.

    2002-08-01

    Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.

  9. Multi-KW dc distribution system technology research study

    NASA Technical Reports Server (NTRS)

    Dawson, S. G.

    1978-01-01

    The Multi-KW DC Distribution System Technology Research Study is the third phase of the NASA/MSFC study program. The purpose of this contract was to complete the design of the integrated technology test facility, provide test planning, support test operations and evaluate test results. The subjet of this study is a continuation of this contract. The purpose of this continuation is to study and analyze high voltage system safety, to determine optimum voltage levels versus power, to identify power distribution system components which require development for higher voltage systems and finally to determine what modifications must be made to the Power Distribution System Simulator (PDSS) to demonstrate 300 Vdc distribution capability.

  10. The SA-2239/WLQ-4(V) Cutty Sark distribution system

    NASA Technical Reports Server (NTRS)

    Vulcan, A.; Ho, J.

    1981-01-01

    A redundant frequency and time distribution system provides a multiplicity of isolated outputs, all of which are derived from three atomic frequency standards. The distribution system monitors input parameters of the signals coming from the Cesium Standards and selects one to be the primary standard, phase locks an internal oscillator which has excellent aging characteristics in the open loop mode and acts as a filter to provide phase noise improvement, and generates 1 megahertz and 100 kHz by direct synthesis. Additionally, the system distributes RF and timing signals consisting of 5 MHz, 1 MHz, 100 kHz, BCD Time-of-Day, 1 pps and 1 ppm.

  11. Integrated Distribution Management System for Alabama Principal Investigator

    SciTech Connect

    Schatz, Joe

    2013-03-31

    Southern Company Services, under contract with the Department of Energy, along with Alabama Power, Alstom Grid (formerly AREVA T&D) and others moved the work product developed in the first phase of the Integrated Distribution Management System (IDMS) from “Proof of Concept” to true deployment through the activity described in this Final Report. This Project – Integrated Distribution Management Systems in Alabama – advanced earlier developed proof of concept activities into actual implementation and furthermore completed additional requirements to fully realize the benefits of an IDMS. These tasks include development and implementation of a Distribution System based Model that enables data access and enterprise application integration.

  12. Distributed Fusion Receding Horizon Filtering in Linear Stochastic Systems

    NASA Astrophysics Data System (ADS)

    Song, IlYoung; Kim, DuYong; Kim, YongHoon; Lee, SukJae; Shin, Vladimir

    2009-12-01

    This paper presents a distributed receding horizon filtering algorithm for multisensor continuous-time linear stochastic systems. Distributed fusion with a weighted sum structure is applied to local receding horizon Kalman filters having different horizon lengths. The fusion estimate of the state of a dynamic system represents the optimal linear fusion by weighting matrices under the minimum mean square error criterion. The key contribution of this paper lies in the derivation of the differential equations for determining the error cross-covariances between the local receding horizon Kalman filters. The subsequent application of the proposed distributed filter to a linear dynamic system within a multisensor environment demonstrates its effectiveness.

  13. Investigations into Distribution System Nitrification: Simulated Systems and Microelectrode Biofilm Profiling

    EPA Science Inventory

    Results from USEPA research investigating drinking water distribution system nitrification will be presented. The two research areas include: (1) microbial community and reactor performance data from simulated drinking water distribution system using annular reactors and (2) mi...

  14. Seismic Fragility of the LANL Fire Water Distribution System

    SciTech Connect

    Greg Mertz Jason Cardon Mike Salmon

    2007-03-30

    The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10{sup -3} that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels

  15. Energy loss analysis of an integrated space power distribution system

    NASA Technical Reports Server (NTRS)

    Kankam, M. D.; Ribeiro, P. F.

    1992-01-01

    The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

  16. Transparent Ada rendezvous in a fault tolerant distributed system

    NASA Technical Reports Server (NTRS)

    Racine, Roger

    1986-01-01

    There are many problems associated with distributing an Ada program over a loosely coupled communication network. Some of these problems involve the various aspects of the distributed rendezvous. The problems addressed involve supporting the delay statement in a selective call and supporting the else clause in a selective call. Most of these difficulties are compounded by the need for an efficient communication system. The difficulties are compounded even more by considering the possibility of hardware faults occurring while the program is running. With a hardware fault tolerant computer system, it is possible to design a distribution scheme and communication software which is efficient and allows Ada semantics to be preserved. An Ada design for the communications software of one such system will be presented, including a description of the services provided in the seven layers of an International Standards Organization (ISO) Open System Interconnect (OSI) model communications system. The system capabilities (hardware and software) that allow this communication system will also be described.

  17. Maximum a posteriori estimation of spectral reflectance from color image and multipoint spectral measurements.

    PubMed

    Murakami, Yuri; Ietomi, Kunihiko; Yamaguchi, Masahiro; Ohyama, Nagaaki

    2007-10-01

    Accurate color image reproduction under arbitrary illumination can be realized if the spectral reflectance functions in a scene are obtained. Although multispectral imaging is one of the promising methods to obtain the reflectance of a scene, it is expected to reduce the number of color channels without significant loss of accuracy. This paper presents what we believe to be a new method for estimating spectral reflectance functions from color image and multipoint spectral measurements based on maximum a posteriori (MAP) estimation. Multipoint spectral measurements are utilized as auxiliary information to improve the accuracy of spectral reflectance estimated from image data. Through simulations, it is confirmed that the proposed method improves the estimation accuracy, particularly when a scene includes subjects that belong to various categories.

  18. MEASURING AND MODELING VARIATIONS IN DISTRIBUTION SYSTEM WATER QUALITY

    EPA Science Inventory

    The authors describe a field study that examined the effects of hydraulic mixing on water quality variations in a distribution system. Conducted at the North Penn Water Authority (average production of 5 mgd and 225 mi of distribution pipe), the study incorporated a field samplin...

  19. Benefits of Power Electronic Interfaces for Distributed Energy Systems

    SciTech Connect

    Kroposki, B.; Pink, C.; DeBlasio, R.; Thomas, H.; Simoes, M.; Sen, P. K.

    2006-01-01

    Optimization of overall electrical system performance is important for the long-term economic viability of distributed energy (DE) systems. With the increasing use of DE systems in industry and its technological advancement, it is becoming more important to understand the integration of these systems with the electric power systems. New markets and benefits for distributed energy applications include the ability to provide ancillary services, improve energy efficiency, enhance power system reliability, and allow customer choice. Advanced power electronic (PE) interfaces will allow DE systems to provide increased functionality through improved power quality and voltage/VAR support, increase electrical system compatibility by reducing the fault contributions, and flexibility in operations with various other DE sources, while reducing overall interconnection costs. This paper examines the system integration and optimization issues associated with DE systems and show the benefits of using PE interfaces for such applications.

  20. Using distributed OLTP technology in a high performance storage system

    SciTech Connect

    Tyler, T.W.; Fisher, D.S.

    1995-03-01

    The design of scaleable mass storage systems requires various system components to be distributed across multiple processors. Most of these processes maintain persistent database-type information (i.e., metadata) on the resources they are responsible for managing (e.g., bitfiles, bitfile segments, physical volumes, virtual volumes, cartridges, etc.). These processes all participate in fulfilling end-user requests and updating metadata information. A number of challenges arise when distributed processes attempt to maintain separate metadata resources with production-level integrity and consistency. For example, when requests fail, metadata changes made by the various processes must be aborted or rolled back. When requests are successful, all metadata changes must be committed together. If all metadata changes cannot be committed together for some reason, then all metadata changes must be rolled back to the previous consistent state. Lack of metadata consistency jeopardizes storage system integrity. Distributed on-line transaction processing (OLTP) technology can be applied to distributed mass storage systems as the mechanism for managing the consistency of distributed metadata. OLTP concepts are familiar to manN, industries such as banking and financial services but are less well known and understood in scientific and technical computing. As mass storage systems and other products are designed using distributed processing and data-management strategies for performance, scalability, and/or availability reasons, distributed OLTP technology can be applied to solve the inherent challenges raised by such environments. This paper discusses the benefits in using distributed transaction processing products. Design and implementation experiences using the Encina OLTP product from Transarc in the High Performance Storage System are presented in more detail as a case study for how this technology can be applied to mass storage systems designed for distributed environments.

  1. Modeling and Verification of Distributed Generation and Voltage Regulation Equipment for Unbalanced Distribution Power Systems; Annual Subcontract Report, June 2007

    SciTech Connect

    Davis, M. W.; Broadwater, R.; Hambrick, J.

    2007-07-01

    This report summarizes the development of models for distributed generation and distribution circuit voltage regulation equipment for unbalanced power systems and their verification through actual field measurements.

  2. Data transmission system with distributed microprocessors

    DOEpatents

    Nambu, Shigeo

    1985-01-01

    A data transmission system having a common request line and a special request line in addition to a transmission line. The special request line has priority over the common request line. A plurality of node stations are multi-drop connected to the transmission line. Among the node stations, a supervising station is connected to the special request line and takes precedence over other slave stations to become a master station. The master station collects data from the slave stations. The station connected to the common request line can assign a master control function to any station requesting to be assigned the master control function within a short period of time. Each station has an auto response control circuit. The master station automatically collects data by the auto response controlling circuit independently of the microprocessors of the slave stations.

  3. Operating tool for a distributed data and information management system

    NASA Astrophysics Data System (ADS)

    Reck, C.; Mikusch, E.; Kiemle, S.; Wolfmüller, M.; Böttcher, M.

    2002-07-01

    The German Remote Sensing Data Center has developed the Data Information and Management System DIMS which provides multi-mission ground system services for earth observation product processing, archiving, ordering and delivery. DIMS successfully uses newest technologies within its services. This paper presents the solution taken to simplify operation tasks for this large and distributed system.

  4. Software metrics: Software quality metrics for distributed systems. [reliability engineering

    NASA Technical Reports Server (NTRS)

    Post, J. V.

    1981-01-01

    Software quality metrics was extended to cover distributed computer systems. Emphasis is placed on studying embedded computer systems and on viewing them within a system life cycle. The hierarchy of quality factors, criteria, and metrics was maintained. New software quality factors were added, including survivability, expandability, and evolvability.

  5. Spatial distribution read-out system for thermoluminescence sheets

    NASA Technical Reports Server (NTRS)

    Yamamoto, I.; Tomiyama, T.; Imaeda, K.; Ninagawa, K.; Wada, T.; Yamashita, Y.; Misaki, A.

    1985-01-01

    A spatial distribution read-out system of thermoluminescence (TL) sheets is developed. This system consists of high gain image intensifier, a CCD-TV camera, a video image processor and a host computer. This system has been applied to artificial TL sheets (BaSO4:Eu doped) for detecting high energy electromagnetic shower and heavy nuclei tracks.

  6. Multi-point quasi-rational approximants for the modified Bessel function I1(x)

    NASA Astrophysics Data System (ADS)

    Martin, P.; Olivares, J.; Cortés-Vega, L.; Sotomayor, A.

    2016-08-01

    Approximants for the modified Bessel function I1(x) has been found using the multi-point quasi-rational technique. The approximations here determined has good accuracy for any positive value of the variable, and it seems to be adequate for most of the works where this function are used. Furthermore, the approximants are simple to calculate numerically in a direct way or using any usual MAPLE or MATLAB software.

  7. Nd:GGG disk laser with multipoint spatially periodic optical pumping

    NASA Astrophysics Data System (ADS)

    Guryev, D. A.; Nikolaev, D. A.; Tsvetkov, V. B.

    2016-04-01

    The results of the study of the output laser beam spatial characteristics of the Nd:Gd3Ga5O12 (Nd:GGG) disk laser with multipoint spatially periodic diode-pumping are presented. The presence of the optical coupling between the TEM00 lasing channels is demonstrated. The phase-locking of channels was realized due to partial overlapping of laser beams inside the pumped areas of the active element disk.

  8. Combined Operation of AC and DC Distribution System with Distributed Generation Units

    NASA Astrophysics Data System (ADS)

    Noroozian, Reza; Abedi, Mehrdad; Gharehpetian, Gevorg

    2010-07-01

    This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.

  9. Saguaro: A distributed operating system based on pools of servicers

    NASA Astrophysics Data System (ADS)

    Andrews, G. R.; Schlichting, R. D.

    1985-03-01

    The progress achieved during the first year of the integrated Saguaro distributed operating system project is presented. The major accomplishments were the completion of the initial design and preliminary implementation of several system components, the subsequent refinement of the user interface and the file system, and the investigation into the use of a universal type system to type data and specify interfaces in the operating system.

  10. System-wide power management control via clock distribution network

    DOEpatents

    Coteus, Paul W.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Reed, Don D.

    2015-05-19

    An apparatus, method and computer program product for automatically controlling power dissipation of a parallel computing system that includes a plurality of processors. A computing device issues a command to the parallel computing system. A clock pulse-width modulator encodes the command in a system clock signal to be distributed to the plurality of processors. The plurality of processors in the parallel computing system receive the system clock signal including the encoded command, and adjusts power dissipation according to the encoded command.

  11. MICROBIOLOGICAL CHARACTERIZATION OF BACTERIA INHABITING A WATER DISTRIBUTION SYSTEM SIMULATOR

    EPA Science Inventory

    The impact of chlorination and chloramination treatments on heterotrophic bacteria (HB) and ammonia oxidizing bacteria (AOB) inhabiting a water distribution system simulator was investigated. Notable changes in bacterial densities were observed during this monitoring study. For e...

  12. Short circuit protection for a power distribution system

    NASA Technical Reports Server (NTRS)

    Owen, J. R., III

    1969-01-01

    Sensing circuit detects when the output from a matrix is present and when it should be present. The circuit provides short circuit protection for a power distribution system where the selection of the driven load is accomplished by digital logic.

  13. Research study on multi-KW DC distribution system

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.

    1975-01-01

    Power distribution system noise and transient stress on switchgear in large space vehicle power systems were investigated in terms of the effect of flight designs of long power distribution cables on load interface EMI requirements. A fifty meter cable pair was simulated to study interactions between the cable, load, and power source terminations. Power system noise characteristics were evaluated based on current spacecraft data, interface hardware filter designs, and power cable parameters. Parametric approaches were defined for evaluating switching transients at various distribution voltage levels. It is concluded that the state-of-the-art semiconductor switches represent a viable approach toward the implementation of power system design with distribution voltages of 120 VDC or less. The interface definition and design for the bus control unit was updated to be consistent with the established requirements.

  14. Intelligent decision support algorithm for distribution system restoration.

    PubMed

    Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

    2016-01-01

    Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network.

  15. Impact of SolarSmart Subdivisions on SMUD's Distribution System

    SciTech Connect

    McNutt, P.; Hambrick, J.; Keesee, M.; Brown, D.

    2009-07-01

    This study analyzes the distribution impacts of high penetrations of grid-integrated renewable energy systems, specifically photovoltaic (PV) equipped SolarSmart Homes found in the Anatolia III Residential Community.

  16. Intelligent decision support algorithm for distribution system restoration.

    PubMed

    Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

    2016-01-01

    Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network. PMID:27512634

  17. A comparative study of electric power distribution systems for spacecraft

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A.; King, Roger J.

    1990-01-01

    The electric power distribution systems for spacecraft are compared concentrating on two interrelated issues: the choice between dc and high frequency ac, and the converter/inverter topology to be used at the power source. The relative merits of dc and ac distribution are discussed. Specific converter and inverter topologies are identified and analyzed in detail for the purpose of detailed comparison. Finally, specific topologies are recommended for use in dc and ac systems.

  18. Electric Transport Traction Power Supply System With Distributed Energy Sources

    NASA Astrophysics Data System (ADS)

    Abramov, E. Y.; Schurov, N. I.; Rozhkova, M. V.

    2016-04-01

    The paper states the problem of traction substation (TSS) leveling of daily-load curve for urban electric transport. The circuit of traction power supply system (TPSS) with distributed autonomous energy source (AES) based on photovoltaic (PV) and energy storage (ES) units is submitted here. The distribution algorithm of power flow for the daily traction load curve leveling is also introduced in this paper. In addition, it illustrates the implemented experiment model of power supply system.

  19. Multipoint Measurements and Global Simulations of the June 23, 2015 Geomagnetic Storm

    NASA Astrophysics Data System (ADS)

    Buzulukova, Natalia; Fok, Mei-Ching; Moore, Thomas E.; Glocer, Alex; Dorelli, John; Sibeck, David; Angelopoulos, Vassilis; Valek, Phil; McComas, David

    2016-04-01

    On 22-23 June 2015 a severe geomagnetic storm occurred with Dst minimum of approximately -200nT. During this extreme event, multipoint observations of magnetospheric dynamics were obtained by a fleet of Geospace spacecraft including MMS, TWINS, Van-Allen Probes and THEMIS. Extensive data coverage allows us to examine the responses of the ring current, radiation belts, ion composition and wave activity during this unusual event, both for the main phase of the storm as well as for the recovery phase. We present results of analysis of satellite data and simulation from a global coupled MHD-ring current model-radiation belt model (BATSRUS-CIMI) to connect multipoint observations from different parts of the magnetosphere. The output of virtual s/c in the global model is calculated and compared with the observations. The analysis helps to identify different magnetospheric domains from multipoint measurements and various magnetospheric boundary motions. We find the model is able to capture the global structure of the magnetosphere. We also explore how the initial disturbance from the solar wind propagates through the magnetosphere causing energization of plasma in the inner magnetosphere and producing severe geomagnetic activity.

  20. A distributed data base management system. [for Deep Space Network

    NASA Technical Reports Server (NTRS)

    Bryan, A. I.

    1975-01-01

    Major system design features of a distributed data management system for the NASA Deep Space Network (DSN) designed for continuous two-way deep space communications are described. The reasons for which the distributed data base utilizing third-generation minicomputers is selected as the optimum approach for the DSN are threefold: (1) with a distributed master data base, valid data is available in real-time to support DSN management activities at each location; (2) data base integrity is the responsibility of local management; and (3) the data acquisition/distribution and processing power of a third-generation computer enables the computer to function successfully as a data handler or as an on-line process controller. The concept of the distributed data base is discussed along with the software, data base integrity, and hardware used. The data analysis/update constraint is examined.

  1. Distributed data base systems with special emphasis toward POREL

    NASA Technical Reports Server (NTRS)

    Neuhold, E. J.

    1984-01-01

    In the last few years a number of research and advanced development projects have resulted in distributed data base management prototypes. POREL, developed at the University of Stuttgart, is a multiuser, distributed, relational system developed for wide and local area networks of minicomputers and advanced micros. The general objectives of such data base systems and the architecture of POREL are discussed. In addition a comparison of some of the the existing distributed DMBS is included to provide the reader with information about the current state of the art.

  2. A Petri net controller for distributed hierarchical systems. Thesis

    NASA Technical Reports Server (NTRS)

    Peck, Joseph E.

    1991-01-01

    The solutions to a wide variety of problems are often best organized as a distributed hierarchical system. These systems can be graphically and mathematically modeled through the use of Petri nets, which can easily represent synchronous, asynchronous, and concurrent operations. This thesis presents a controller implementation based on Petri nets and a design methodology for the interconnection of distributed Petri nets. Two case studies are presented in which the controller operates a physical system, the Center for Intelligent Robotic Systems for Space Exploration Dual Arm Robotic Testbed.

  3. Modeling biometric systems using the general pareto distribution (GPD)

    NASA Astrophysics Data System (ADS)

    Shi, Zhixin; Kiefer, Frederick; Schneider, John; Govindaraju, Venu

    2008-03-01

    Statistical modeling of biometric systems at the score level is extremely important. It is the foundation of the performance assessment of biometric systems including determination of confidence intervals and test sample size for simulations, and performance prediction of real world systems. Statistical modeling of multimodal biometric systems allows the development of a methodology to integrate information from multiple biometric sources. We present a novel approach for estimating the marginal biometric matching score distributions by using extreme value theory in conjunction with non-parametric methods. Extreme Value Theory (EVT) is based on the modeling of extreme events represented by data which has abnormally low or high values in the tails of the distributions. Our motivation stems from the observation that the tails of the biometric score distributions are often difficult to estimate using other methods due to lack of sufficient numbers of training samples. However, good estimates of the tails of biometric distributions are essential for defining the decision boundaries. We present EVT based novel procedures for fitting a score distribution curve. A general non-parametric method is used for fitting the majority part of the distribution curve, and a parametric EVT model - the general Pareto distribution - is used for fitting the tails of the curve. We also demonstrate the advantage of applying the EVT by experiments.

  4. Image processing system to analyze droplet distributions in sprays

    NASA Technical Reports Server (NTRS)

    Bertollini, Gary P.; Oberdier, Larry M.; Lee, Yong H.

    1987-01-01

    An image processing system was developed which automatically analyzes the size distributions in fuel spray video images. Images are generated by using pulsed laser light to freeze droplet motion in the spray sample volume under study. This coherent illumination source produces images which contain droplet diffraction patterns representing the droplets degree of focus. The analysis is performed by extracting feature data describing droplet diffraction patterns in the images. This allows the system to select droplets from image anomalies and measure only those droplets considered in focus. Unique features of the system are the totally automated analysis and droplet feature measurement from the grayscale image. The feature extraction and image restoration algorithms used in the system are described. Preliminary performance data is also given for two experiments. One experiment gives a comparison between a synthesized distribution measured manually and automatically. The second experiment compares a real spray distribution measured using current methods against the automatic system.

  5. Distributed computing environments for future space control systems

    NASA Technical Reports Server (NTRS)

    Viallefont, Pierre

    1993-01-01

    The aim of this paper is to present the results of a CNES research project on distributed computing systems. The purpose of this research was to study the impact of the use of new computer technologies in the design and development of future space applications. The first part of this study was a state-of-the-art review of distributed computing systems. One of the interesting ideas arising from this review is the concept of a 'virtual computer' allowing the distributed hardware architecture to be hidden from a software application. The 'virtual computer' can improve system performance by adapting the best architecture (addition of computers) to the software application without having to modify its source code. This concept can also decrease the cost and obsolescence of the hardware architecture. In order to verify the feasibility of the 'virtual computer' concept, a prototype representative of a distributed space application is being developed independently of the hardware architecture.

  6. Design of Distributed Engine Control Systems with Uncertain Delay

    PubMed Central

    Li, Yanxi; Sun, Xu

    2016-01-01

    Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC) is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS). Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method. PMID:27669005

  7. Design distributed simulation platform for vehicle management system

    NASA Astrophysics Data System (ADS)

    Wen, Zhaodong; Wang, Zhanlin; Qiu, Lihua

    2006-11-01

    Next generation military aircraft requires the airborne management system high performance. General modules, data integration, high speed data bus and so on are needed to share and manage information of the subsystems efficiently. The subsystems include flight control system, propulsion system, hydraulic power system, environmental control system, fuel management system, electrical power system and so on. The unattached or mixed architecture is changed to integrated architecture. That means the whole airborne system is regarded into one system to manage. So the physical devices are distributed but the system information is integrated and shared. The process function of each subsystem are integrated (including general process modules, dynamic reconfiguration), furthermore, the sensors and the signal processing functions are shared. On the other hand, it is a foundation for power shared. Establish a distributed vehicle management system using 1553B bus and distributed processors which can provide a validation platform for the research of airborne system integrated management. This paper establishes the Vehicle Management System (VMS) simulation platform. Discuss the software and hardware configuration and analyze the communication and fault-tolerant method.

  8. Automated power distribution system hardware. [for space station power supplies

    NASA Technical Reports Server (NTRS)

    Anderson, Paul M.; Martin, James A.; Thomason, Cindy

    1989-01-01

    An automated power distribution system testbed for the space station common modules has been developed. It incorporates automated control and monitoring of a utility-type power system. Automated power system switchgear, control and sensor hardware requirements, hardware design, test results, and potential applications are discussed. The system is designed so that the automated control and monitoring of the power system is compatible with both a 208-V, 20-kHz single-phase AC system and a high-voltage (120 to 150 V) DC system.

  9. An expert system for a distributed real-time trainer

    NASA Technical Reports Server (NTRS)

    Purinton, Steven C.; Wang, Caroline K.

    1988-01-01

    The problem addressed by this expert system concerns the expansion of capability of a Real Time Trainer for the Spacelab flight crew. As requirements for more models or fidelity are placed upon the system, expansion is necessary. The simulator can be expanded using a larger processor or by going to a distributed system and expand by adding additional processors. The distributed system is preferable because it is more economical and can be expanded in a more incremental manner. An expert system was developed to evaluate modeling and timing capability within a real time training simulator. The expert system is based upon a distributed configuration. Components of the modeled system are control tasks, network tasks, emulator tasks, processors, displays, and a network. The distributed module expert system (DMES) allows the configuring of processors, tasks, display use, keyboard use, and selection of alternate methods to update the data buffer. Modules can be defined with execution occurring in a specific processor on a network. The system consists of a knowledge front end editor to interactively generate or update the knowledge base, an inference engine, a display module, and a recording module.

  10. Distribution System Reliability Analysis for Smart Grid Applications

    NASA Astrophysics Data System (ADS)

    Aljohani, Tawfiq Masad

    Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. To address its reliability concerns, the power utilities and interested parties have spent extensive amount of time and effort to analyze and study the reliability of the generation and transmission sectors of the power grid. Only recently has attention shifted to be focused on improving the reliability of the distribution network, the connection joint between the power providers and the consumers where most of the electricity problems occur. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in conducting this thesis is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. The goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility's distribution system and measure the potential improvement of its reliability. The software used in this work is DISREL, which is intelligent power distribution software that is developed by General Reliability Co.

  11. Description of a 20 kilohertz power distribution system

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution links multiphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  12. Description of a 20 Kilohertz power distribution system

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution link; mulitphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  13. Optimization and capacity expansion of a water distribution system

    NASA Astrophysics Data System (ADS)

    Hsu, Nien-Sheng; Cheng, Wei-Chen; Cheng, Wen-Ming; Wei, Chih-Chiang; Yeh, William W.-G.

    2008-05-01

    This paper develops an iterative procedure for capacity expansion studies for water distribution systems. We propose a methodology to analyze an existing water distribution system and identify the potential bottlenecks in the system. Based on the results, capacity expansion alternatives are proposed and evaluated for improving the efficiency of water supply. The methodology includes a network flow based optimization model, four evaluation indices, and a series of evaluation steps. We first use a directed graph to configure the water distribution system into a network. The network flow based model optimizes the water distribution in the system so that different expansion alternatives can be evaluated on a comparable basis. This model lends itself to linear programming (LP) and can be easily solved by a standard LP code. The results from the evaluation tool help to identify the bottlenecks in the water distribution system and provide capacity expansion alternatives. A useful complementary tool for decision making is composed of a series of evaluation steps with the bottleneck findings, capacity expansion alternatives, and the evaluation of results. We apply the proposed methodology to the Tou-Qian River Basin, located in the northern region of Taiwan, to demonstrate its applicability in optimization and capacity expansion studies.

  14. Industrial Power Distribution System Reliability Assessment utilizing Markov Approach

    NASA Astrophysics Data System (ADS)

    Guzman-Rivera, Oscar R.

    A method to perform power system reliability analysis using Markov Approach, Reliability Block Diagrams and Fault Tree analysis has been presented. The Markov method we use is a state space model and is based on state diagrams generated for a one line industrial power distribution system. The Reliability block diagram (RBD) method is a graphical and calculation tool used to model the distribution power system of an industrial facility. Quantitative reliability estimations on this work are based on CARMS and Block Sim simulations as well as state space, RBD's and Failure Mode analyses. The power system reliability was assessed and the main contributors to power system reliability have been identified, both qualitatively and quantitatively. Methods to improve reliability have also been provided including redundancies and protection systems that might be added to the system in order to improve reliability.

  15. 62. View of amplifiermodulator control system with power distribution panel ...

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

    62. View of amplifier-modulator control system with power distribution panel on left, control power supply in middle, and amplifier modulator on right, second floor in transmitter building no. 102. - 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

  16. Distributed Systems of Generalizing as the Basis of Workplace Learning

    ERIC Educational Resources Information Center

    Virkkunen, Jaakko; Pihlaja, Juha

    2004-01-01

    This article proposes a new way of conceptualizing workplace learning as distributed systems of appropriation, development and the use of practice-relevant generalizations fixed within mediational artifacts. This article maintains that these systems change historically as technology and increasingly sophisticated forms of production develop.…

  17. An integrated drug prescription and distribution system: challenges and opportunities.

    PubMed

    Lanssiers, R; Everaert, E; De Win, M; Van De Velde, R; De Clercq, H

    2002-01-01

    Using the hospital's drug prescription and distribution system as a guide, benefits and drawbacks of a medical activity management system that is tightly integrated with the supply chain management of a hospital will be discussed from the point of view of various participating healthcare actors. PMID:15058416

  18. Understanding and Controlling iron Release in Distribution Systems

    EPA Science Inventory

    Generation of red-water resulting from the release of iron from drinking water distribution system materials is a major consumer complaint of drinking water systems. The objective of this presentation is to provide a fundamental basis for iron release from drinking water distrib...

  19. Microflora of drinking water distributed through decentralized supply systems (Tomsk)

    NASA Astrophysics Data System (ADS)

    Khvaschevskaya, A. A.; Nalivaiko, N. G.; Shestakova, A. V.

    2016-03-01

    The paper considers microbiological quality of waters from decentralized water supply systems in Tomsk. It has been proved that there are numerous microbial contaminants of different types. The authors claim that the water distributed through decentralized supply systems is not safe to drink without preliminary treatment.

  20. Impact of Arsenic Treatment Systems on Distribution System Water

    EPA Science Inventory

    Under the USEPA Arsenic Demonstration Program, 50 arsenic removal treatment systems were installed and their performance evaluated over a period of one to three years. The program was limited to small systems whose population served were less than 10,000. Ten of the systems were ...

  1. The distribution of period ratios in Kepler planetary systems

    NASA Astrophysics Data System (ADS)

    Steffen, Jason H.; Hwang, Jason A.

    2015-01-01

    Kepler's multi-planet systems are a valuable tool to understand the architectures and dynamics of the inner parts of planetary systems. I present an analysis of the distribution of orbital period ratios from candidate systems identified in the Quarter 8 catalog (Burke et al. 2014). This distribution is corrected for the effects of geometric transit probabilities and the completeness of the data reduction pipeline. We find that the distribution of period ratios falls as a power law with exponent -1.26 ± 0.05. We also identify a new, statistically significant feature near a period ratio of 2.2. These observations may provide insights into the formation and evolution of these systems.

  2. Intercommunications in Real Time, Redundant, Distributed Computer System

    NASA Technical Reports Server (NTRS)

    Zanger, H.

    1980-01-01

    An investigation into the applicability of fiber optic communication techniques to real time avionic control systems, in particular the total automatic flight control system used for the VSTOL aircraft is presented. The system consists of spatially distributed microprocessors. The overall control function is partitioned to yield a unidirectional data flow between the processing elements (PE). System reliability is enhanced by the use of triple redundancy. Some general overall system specifications are listed here to provide the necessary background for the requirements of the communications system.

  3. Distributed intrusion detection system based on fuzzy rules

    NASA Astrophysics Data System (ADS)

    Qiao, Peili; Su, Jie; Liu, Yahui

    2006-04-01

    Computational Intelligence is the theory and method solving problems by simulating the intelligence of human using computer and it is the development of Artificial Intelligence. Fuzzy Technique is one of the most important theories of computational Intelligence. Genetic Fuzzy Technique and Neuro-Fuzzy Technique are the combination of Fuzzy Technique and novel techniques. This paper gives a distributed intrusion detection system based on fuzzy rules that has the characters of distributed parallel processing, self-organization, self-learning and self-adaptation by the using of Neuro-Fuzzy Technique and Genetic Fuzzy Technique. Specially, fuzzy decision technique can be used to reduce false detection. The results of the simulation experiment show that this intrusion detection system model has the characteristics of distributed, error tolerance, dynamic learning, and adaptation. It solves the problem of low identifying rate to new attacks and hidden attacks. The false detection rate is low. This approach is efficient to the distributed intrusion detection.

  4. The structure of the clouds distributed operating system

    NASA Technical Reports Server (NTRS)

    Dasgupta, Partha; Leblanc, Richard J., Jr.

    1989-01-01

    A novel system architecture, based on the object model, is the central structuring concept used in the Clouds distributed operating system. This architecture makes Clouds attractive over a wide class of machines and environments. Clouds is a native operating system, designed and implemented at Georgia Tech. and runs on a set of generated purpose computers connected via a local area network. The system architecture of Clouds is composed of a system-wide global set of persistent (long-lived) virtual address spaces, called objects that contain persistent data and code. The object concept is implemented at the operating system level, thus presenting a single level storage view to the user. Lightweight treads carry computational activity through the code stored in the objects. The persistent objects and threads gives rise to a programming environment composed of shared permanent memory, dispensing with the need for hardware-derived concepts such as the file systems and message systems. Though the hardware may be distributed and may have disks and networks, the Clouds provides the applications with a logically centralized system, based on a shared, structured, single level store. The current design of Clouds uses a minimalist philosophy with respect to both the kernel and the operating system. That is, the kernel and the operating system support a bare minimum of functionality. Clouds also adheres to the concept of separation of policy and mechanism. Most low-level operating system services are implemented above the kernel and most high level services are implemented at the user level. From the measured performance of using the kernel mechanisms, we are able to demonstrate that efficient implementations are feasible for the object model on commercially available hardware. Clouds provides a rich environment for conducting research in distributed systems. Some of the topics addressed in this paper include distributed programming environments, consistency of persistent data

  5. Parallel Computing Environments and Methods for Power Distribution System Simulation

    SciTech Connect

    Lu, Ning; Taylor, Zachary T.; Chassin, David P.; Guttromson, Ross T.; Studham, Scott S.

    2005-11-10

    The development of cost-effective high-performance parallel computing on multi-processor super computers makes it attractive to port excessively time consuming simulation software from personal computers (PC) to super computes. The power distribution system simulator (PDSS) takes a bottom-up approach and simulates load at appliance level, where detailed thermal models for appliances are used. This approach works well for a small power distribution system consisting of a few thousand appliances. When the number of appliances increases, the simulation uses up the PC memory and its run time increases to a point where the approach is no longer feasible to model a practical large power distribution system. This paper presents an effort made to port a PC-based power distribution system simulator (PDSS) to a 128-processor shared-memory super computer. The paper offers an overview of the parallel computing environment and a description of the modification made to the PDSS model. The performances of the PDSS running on a standalone PC and on the super computer are compared. Future research direction of utilizing parallel computing in the power distribution system simulation is also addressed.

  6. A Distributed Simulation Software System for Multi-Spacecraft Missions

    NASA Technical Reports Server (NTRS)

    Burns, Richard; Davis, George; Cary, Everett

    2003-01-01

    The paper will provide an overview of the web-based distributed simulation software system developed for end-to-end, multi-spacecraft mission design, analysis, and test at the NASA Goddard Space Flight Center (GSFC). This software system was developed for an internal research and development (IR&D) activity at GSFC called the Distributed Space Systems (DSS) Distributed Synthesis Environment (DSE). The long-term goal of the DSS-DSE is to integrate existing GSFC stand-alone test beds, models, and simulation systems to create a "hands on", end-to-end simulation environment for mission design, trade studies and simulations. The short-term goal of the DSE was therefore to develop the system architecture, and then to prototype the core software simulation capability based on a distributed computing approach, with demonstrations of some key capabilities by the end of Fiscal Year 2002 (FY02). To achieve the DSS-DSE IR&D objective, the team adopted a reference model and mission upon which FY02 capabilities were developed. The software was prototyped according to the reference model, and demonstrations were conducted for the reference mission to validate interfaces, concepts, etc. The reference model, illustrated in Fig. 1, included both space and ground elements, with functional capabilities such as spacecraft dynamics and control, science data collection, space-to-space and space-to-ground communications, mission operations, science operations, and data processing, archival and distribution addressed.

  7. Distributed PACS using distributed file system with hierarchical meta data servers.

    PubMed

    Hiroyasu, Tomoyuki; Minamitani, Yoshiyuki; Miki, Mitsunori; Yokouchi, Hisatake; Yoshimi, Masato

    2012-01-01

    In this research, we propose a new distributed PACS (Picture Archiving and Communication Systems) which is available to integrate several PACSs that exist in each medical institution. The conventional PACS controls DICOM file into one data-base. On the other hand, in the proposed system, DICOM file is separated into meta data and image data and those are stored individually. Using this mechanism, since file is not always accessed the entire data, some operations such as finding files, changing titles, and so on can be performed in high-speed. At the same time, as distributed file system is utilized, accessing image files can also achieve high-speed access and high fault tolerant. The introduced system has a more significant point. That is the simplicity to integrate several PACSs. In the proposed system, only the meta data servers are integrated and integrated system can be constructed. This system also has the scalability of file access with along to the number of file numbers and file sizes. On the other hand, because meta-data server is integrated, the meta data server is the weakness of this system. To solve this defect, hieratical meta data servers are introduced. Because of this mechanism, not only fault--tolerant ability is increased but scalability of file access is also increased. To discuss the proposed system, the prototype system using Gfarm was implemented. For evaluating the implemented system, file search operating time of Gfarm and NFS were compared.

  8. Design and Implementation of Ceph: A Scalable Distributed File System

    SciTech Connect

    Weil, S A; Brandt, S A; Miller, E L; Long, D E; Maltzahn, C

    2006-04-19

    File system designers continue to look to new architectures to improve scalability. Object-based storage diverges from server-based (e.g. NFS) and SAN-based storage systems by coupling processors and memory with disk drives, delegating low-level allocation to object storage devices (OSDs) and decoupling I/O (read/write) from metadata (file open/close) operations. Even recent object-based systems inherit decades-old architectural choices going back to early UNIX file systems, however, limiting their ability to effectively scale to hundreds of petabytes. We present Ceph, a distributed file system that provides excellent performance and reliability with unprecedented scalability. Ceph maximizes the separation between data and metadata management by replacing allocation tables with a pseudo-random data distribution function (CRUSH) designed for heterogeneous and dynamic clusters of unreliable OSDs. We leverage OSD intelligence to distribute data replication, failure detection and recovery with semi-autonomous OSDs running a specialized local object storage file system (EBOFS). Finally, Ceph is built around a dynamic distributed metadata management cluster that provides extremely efficient metadata management that seamlessly adapts to a wide range of general purpose and scientific computing file system workloads. We present performance measurements under a variety of workloads that show superior I/O performance and scalable metadata management (more than a quarter million metadata ops/sec).

  9. Performance analysis of static locking in replicated distributed database systems

    NASA Technical Reports Server (NTRS)

    Kuang, Yinghong; Mukkamala, Ravi

    1991-01-01

    Data replication and transaction deadlocks can severely affect the performance of distributed database systems. Many current evaluation techniques ignore these aspects, because it is difficult to evaluate through analysis and time consuming to evaluate through simulation. A technique is used that combines simulation and analysis to closely illustrate the impact of deadlock and evaluate performance of replicated distributed database with both shared and exclusive locks.

  10. Performance analysis of static locking in replicated distributed database systems

    NASA Technical Reports Server (NTRS)

    Kuang, Yinghong; Mukkamala, Ravi

    1991-01-01

    Data replications and transaction deadlocks can severely affect the performance of distributed database systems. Many current evaluation techniques ignore these aspects, because it is difficult to evaluate through analysis and time consuming to evaluate through simulation. Here, a technique is discussed that combines simulation and analysis to closely illustrate the impact of deadlock and evaluate performance of replicated distributed databases with both shared and exclusive locks.

  11. 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.

  12. Sapphire-fiber-based distributed high-temperature sensing system.

    PubMed

    Liu, Bo; Yu, Zhihao; Hill, Cary; Cheng, Yujie; Homa, Daniel; Pickrell, Gary; Wang, Anbo

    2016-09-15

    We present, for the first time to our knowledge, a sapphire-fiber-based distributed high-temperature sensing system based on a Raman distributed sensing technique. High peak power laser pulses at 532 nm were coupled into the sapphire fiber to generate the Raman signal. The returned Raman Stokes and anti-Stokes signals were measured in the time domain to determine the temperature distribution along the fiber. The sensor was demonstrated from room temperature up to 1200°C in which the average standard deviation is about 3.7°C and a spatial resolution of about 14 cm was achieved. PMID:27628409

  13. Model-Driven Test Generation of Distributed Systems

    NASA Technical Reports Server (NTRS)

    Easwaran, Arvind; Hall, Brendan; Schweiker, Kevin

    2012-01-01

    This report describes a novel test generation technique for distributed systems. Utilizing formal models and formal verification tools, spe cifically the Symbolic Analysis Laboratory (SAL) tool-suite from SRI, we present techniques to generate concurrent test vectors for distrib uted systems. These are initially explored within an informal test validation context and later extended to achieve full MC/DC coverage of the TTEthernet protocol operating within a system-centric context.

  14. A distributed name resolution system in information centric networks

    NASA Astrophysics Data System (ADS)

    Elbreiki, Walid; Arlimatti, Shivaleela; Hassan, Suhaidi; Habbal, Adib; Elshaikh, Mohamed

    2016-08-01

    Information Centric Networks (ICN) is the new paradigm that envisages to shift the Internet away from its existing Point-to-Point architecture to a data centric, where communication is based on named hosts rather than the information stored on these hosts. Name Resolution is the center of attraction for ICN, where Named Data Objects (NDO) are used for identifying the information and guiding for routing or forwarding inside ICN. Recently, several researches use distributed NRS to overcome the problem of interest flooding, congestion and overloading. Yet the distribution of NRS is based on random distribution. How to distribute the NRS is still an important and challenging problem. In this work, we address the problem of distribution of NRS by proposing a new mechanism called Distributed Name Resolution System (DNRS), by considering the time of publishing the NDOs in the NRS. This mechanism partitions the network to distribute the workload among NRSs by increasing storage capacity. In addition, partitioning the network increases flexibility and scalability of NRS. We evaluate the effectiveness of our proposed mechanism, which achieves lesser end-to-end delay with more average throughputs compared to random distribution of NRS without disturbing the underlying routing or forwarding strategies.

  15. Multipoint Plasma Density Measurements from Cluster Wave and Particle Instruments

    NASA Astrophysics Data System (ADS)

    Persoon, A.; Gurnett, D.; Pickett, J.; Canu, P.; Décréau, P.; Laakso, H.; Pedersen, A.; Andre, M.; Parks, G.; Wilber, M.; Reme, H.; Goldstein, M.; Fazakerly, A.

    2001-12-01

    Measurements from instruments onboard the Cluster spacecraft are used to study regions of diminished plasma density inside and poleward of the nightside auroral zone. The plasma density is derived from the digitization of the electron plasma frequency cutoff of the whistler mode auroral hiss, using the electric field spectrum measurements from the Wideband Plasma Wave Instrument (WBD). Two nightside auroral zone crossings, on May 8 and July 21, 2001, each with simultaneous measurements from two Cluster spacecraft, have been selected for this study. Both of these intervals contain multiple low density structures and provide an opportunity to make multi-instrument comparisons of the WBD electric spectrum measurements with the electron plasma frequency measurements of the WHISPER experiment and the spacecraft potential measurements of the Electric Fields and Waves (EFW) experiment. Since the satellite potential measurements are very sensitive to variations in the electron density, EFW spacecraft potential and density measurements will complement the WBD density measurements in the low density regions. Density variations will also be compared to the observed ion fluxes, using the ion distribution functions of the Cluster Ion Spectrometry (CIS) instruments and the low energy electron fluxes, using the electron velocity and energy distributions of the Electron and Current Experiment (PEACE).

  16. A Distributed Approach to System-Level Prognostics

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew J.; Bregon, Anibal; Roychoudhury, Indranil

    2012-01-01

    Prognostics, which deals with predicting remaining useful life of components, subsystems, and systems, is a key technology for systems health management that leads to improved safety and reliability with reduced costs. The prognostics problem is often approached from a component-centric view. However, in most cases, it is not specifically component lifetimes that are important, but, rather, the lifetimes of the systems in which these components reside. The system-level prognostics problem can be quite difficult due to the increased scale and scope of the prognostics problem and the relative Jack of scalability and efficiency of typical prognostics approaches. In order to address these is ues, we develop a distributed solution to the system-level prognostics problem, based on the concept of structural model decomposition. The system model is decomposed into independent submodels. Independent local prognostics subproblems are then formed based on these local submodels, resul ting in a scalable, efficient, and flexible distributed approach to the system-level prognostics problem. We provide a formulation of the system-level prognostics problem and demonstrate the approach on a four-wheeled rover simulation testbed. The results show that the system-level prognostics problem can be accurately and efficiently solved in a distributed fashion.

  17. Assessment of distributed solar power systems: Issues and impacts

    NASA Astrophysics Data System (ADS)

    Moyle, R. A.; Chernoff, H.; Schweizer, T. C.; Patton, J. B.

    1982-11-01

    The installation of distributed solar-power systems presents electric utilities with a host of questions. Some of the technical and economic impacts of these systems are discussed. Among the technical interconnect issues are isolated operation, power quality, line safety, and metering options. Economic issues include user purchase criteria, structures and installation costs, marketing and product distribution costs, and interconnect costs. An interactive computer program that allows easy calculation of allowable system prices and allowable generation-equipment prices was developed as part of this project. It is concluded that the technical problems raised by distributed solar systems are surmountable, but their resolution may be costly. The stringent purchase criteria likely to be imposed by many potential system users and the economies of large-scale systems make small systems (less than 10 to 20 kW) less attractive than larger systems. Utilities that consider life-cycle costs in making investment decisions and third-party investors who have tax and financial advantages are likely to place the highest value on solar-power systems.

  18. 242A Distributed Control System Year 2000 Acceptance Test Report

    SciTech Connect

    TEATS, M.C.

    1999-08-31

    This report documents acceptance test results for the 242-A Evaporator distributive control system upgrade to D/3 version 9.0-2 for year 2000 compliance. This report documents the test results obtained by acceptance testing as directed by procedure HNF-2695. This verification procedure will document the initial testing and evaluation of the potential 242-A Distributed Control System (DCS) operating difficulties across the year 2000 boundary and the calendar adjustments needed for the leap year. Baseline system performance data will be recorded using current, as-is operating system software. Data will also be collected for operating system software that has been modified to correct year 2000 problems. This verification procedure is intended to be generic such that it may be performed on any D/3{trademark} (GSE Process Solutions, Inc.) distributed control system that runs with the VMSTM (Digital Equipment Corporation) operating system. This test may be run on simulation or production systems depending upon facility status. On production systems, DCS outages will occur nine times throughout performance of the test. These outages are expected to last about 10 minutes each.

  19. Determining pre-onset field magnetotail topology from multi-point magnetospheric and ground-based measurements

    NASA Astrophysics Data System (ADS)

    Rae, J.; Murphy, K. R.; Forsyth, C.; Walsh, A. P.; Waters, C. L.; Mann, I. R.; Taylor, M. G.; Angelopoulos, V.; Carr, C.; Singer, H. J.

    2013-12-01

    The temporal sequence of events at substorm onset requires the generation and propagation of electromagnetic waves as the system evolves from its pre- to post-onset state. Such waves offer a unique diagnostic for the dynamics of this system, and the important coupling between the equatorial magnetosphere and auroral onset dynamics in the ionosphere. ULF waves have been shown to be a pivotal aspect of the substorm onset process, their arrival denoting the epicentre of the magnetic and auroral displays in the ionosphere, however the magnetotail region to which this ULF wave epicentre maps is unknown. Equally, what hinders progress in finding the ionospheric counterpart to magnetospheric features is the uncertainty in mapping high-precision but sparse magnetotail measurements of substorm-related phenomena into the ionosphere. We use ULF waves to diagnose pre-onset magnetic field topology by studying the in-situ eigenfrequencies in the magnetotail using cross-phase techniques. We utilise the new multi-point multi-instrument conjunctions in 2013 from THEMIS, Cluster and GOES and the CARISMA and THEMIS ground-based magnetometer arrays to determine field line eigenfrequencies both on the ground and in at least two separate regions in the near- and mid-tail. The field line eigenfrequencies provide a new way to constrain the location of magnetospheric substorm onset, and provide reliable field line mapping estimates.

  20. A new distributed systems scheduling algorithm: a swarm intelligence approach

    NASA Astrophysics Data System (ADS)

    Haghi Kashani, Mostafa; Sarvizadeh, Raheleh; Jameii, Mahdi

    2011-12-01

    The scheduling problem in distributed systems is known as an NP-complete problem, and methods based on heuristic or metaheuristic search have been proposed to obtain optimal and suboptimal solutions. The task scheduling is a key factor for distributed systems to gain better performance. In this paper, an efficient method based on memetic algorithm is developed to solve the problem of distributed systems scheduling. With regard to load balancing efficiently, Artificial Bee Colony (ABC) has been applied as local search in the proposed memetic algorithm. The proposed method has been compared to existing memetic-Based approach in which Learning Automata method has been used as local search. The results demonstrated that the proposed method outperform the above mentioned method in terms of communication cost.

  1. Diagnosing delivery problems in the White House Information Distribution System

    SciTech Connect

    Nahabedian, M.; Shrobe, H.

    1996-12-31

    As part of a collaboration with the White House Office of Media Affairs, members of the MIT Artificial Intelligence Laboratory designed a system, called COMLINK, which distributes a daily stream of documents released by the Office of Media Affairs. Approximately 4000 direct subscribers receive information from this service but more than 100,000 people receive the information through redistribution channels. The information is distributed via Email and the World Wide Web. In such a large scale distribution scheme, there is a constant problem of subscriptions becoming invalid because the user`s Email account has terminated. This causes a backwash of hundreds of {open_quotes}bounced mail{close_quotes} messages per day which must be processed by the operators of the COMLINK system. To manage this annoying but necessary task, an expert system named BMES was developed to diagnose the failures of information delivery.

  2. Curie law for systems described by kappa distributions

    NASA Astrophysics Data System (ADS)

    Livadiotis, George

    2016-01-01

    We derive the magnetization of a system, Pierre Curie's law, for paramagnetic particles out of thermal equilibrium described by kappa distributions. The analysis uses the theory and formulation of the kappa distributions that describe particle systems with a non-zero potential energy. Among other results, emphasis is placed on the effect of kappa distribution on the phenomenon of having strong magnetization at high temperatures. At thermal equilibrium, high temperature leads to weak magnetization. Out of thermal equilibrium, however, strong magnetization at high temperatures is rather possible, if the paramagnetic particle systems reside far from thermal equilibrium, i.e., at small values of kappa. The application of the theory to the space plasma at the outer boundaries of our heliosphere, the inner heliosheath, leads to an estimation of the ion magnetic moment for this space plasma, that is, μ ≈ 138+/-7 \\text{eV/nT} .

  3. Change in the coil distribution of electrodynamic suspension system

    NASA Technical Reports Server (NTRS)

    Tanaka, Hisashi

    1992-01-01

    At the Miyazaki Maglev Test Center, the initial test runs were completed using a system design that required the superconducting coils to be parallel with the ground levitation coils. Recently, the coil distribution was changed to a system such that the two types of coils were perpendicular to each other. Further system changes will lead to the construction of a side wall levitation system. It is hoped that the development will culminate in a system whereby a superconducting coil will maintain all the functions: levitation, propulsion, and guidance.

  4. Multipoint photonic doppler velocimetry using optical lens elements

    DOEpatents

    Frogget, Brent Copely; Romero, Vincent Todd

    2014-04-29

    A probe including a fisheye lens is disclosed to measure the velocity distribution of a moving surface along many lines of sight. Laser light, directed to the surface and then reflected back from the surface, is Doppler shifted by the moving surface, collected into fisheye lens, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to an index-matching lens and eventually to a fisheye lens. The fiber array flat polished and coupled to the index-matching lens using index-matching gel. Numerous fibers in a fiber array project numerous rays through the fisheye lens which in turn project many measurement points at numerous different locations to establish surface coverage over a hemispherical shape with very little crosstalk.

  5. Multipoint linkage detection in the presence of heterogeneity.

    PubMed

    Chiu, Yen-Feng; Liang, Kung-Yee; Beaty, Terri H

    2002-06-01

    Linkage heterogeneity is common for complex diseases. It is well known that loss of statistical power for detecting linkage will result if one assumes complete homogeneity in the presence of linkage heterogeneity. To this end, Smith (1963, Annals of Human Genetics 27, 175-182) proposed an admixture model to account for linkage heterogeneity. It is well known that for this model, the conventional chi-squared approximation to the likelihood ratio test for no linkage does not apply even when the sample size is large. By dealing with nuclear families and one marker at a time for genetic diseases with simple modes of inheritance, score-based test statistics (Liang and Rathouz, 1999, Biometrics 55, 65-74) and likelihood-ratio-based test statistics (Lemdani and Pons, 1995, Biometrics 51, 1033-1041) have been proposed which have a simple large-sample distribution under the null hypothesis of linkage. In this paper, we extend their work to more practical situations that include information from multiple markers and multi-generational pedigrees while allowing for a class of general genetic models. Three different approaches are proposed to eliminate the nuisance parameters in these test statistics. We show that all three approaches lead to the same asymptotic distribution under the null hypothesis of no linkage. Simulation results show that the proposed test statistics have adequate power to detect linkage and that the performances of these two classes of test statistics are quite comparable. We have applied the proposed method to a family study of asthma (Barnes et al., 1996), in which the score-based test shows evidence of linkage with p-value <0.0001 in the region of interest on chromosome 12. Additionally, we have implemented this score-based test within the frequently used computer package GENEHUNTER.

  6. An efficient algorithm for estimating noise covariances in distributed systems

    NASA Technical Reports Server (NTRS)

    Dee, D. P.; Cohn, S. E.; Ghil, M.; Dalcher, A.

    1985-01-01

    An efficient computational algorithm for estimating the noise covariance matrices of large linear discrete stochatic-dynamic systems is presented. Such systems arise typically by discretizing distributed-parameter systems, and their size renders computational efficiency a major consideration. The proposed adaptive filtering algorithm is based on the ideas of Belanger, and is algebraically equivalent to his algorithm. The earlier algorithm, however, has computational complexity proportional to p to the 6th, where p is the number of observations of the system state, while the new algorithm has complexity proportional to only p-cubed. Further, the formulation of noise covariance estimation as a secondary filter, analogous to state estimation as a primary filter, suggests several generalizations of the earlier algorithm. The performance of the proposed algorithm is demonstrated for a distributed system arising in numerical weather prediction.

  7. Large distributed control system using ADA in fusion research

    SciTech Connect

    Woodruff, J. P., LLNL

    1998-04-21

    Construction of the National Ignition Facility laser at Lawrence Livermore National Laboratory features a large distributed control system constructed using object-oriented software engineering techniques. Control of 60,000 devices is effected using a network of some 500 computers that run software written in Ada and communicating through CORBA. The project has completed its final design review; implementation of the first of five planned increments will be delivered at the end of fiscal year 1998. Preliminary measures of the distributed controls performance confirm the design decisions reported in this paper, and the measurement and supporting simulation of full system performance continue.

  8. Multi-point sources and imaging compound infrared target simulator

    NASA Astrophysics Data System (ADS)

    Shi, Rui; Xu, Rui; Wang, Hongjie; Wang, Xin; Wu, Di; Li, Zhuo

    2014-11-01

    Infrared target simulator is an important unit in guidance hardware-in-the-loop simulation systems. It is used to simulate the radiation and motion characteristics of target, decoy and background. This paper proposed a multi-channel IR target simulator. It could generate one IR point target, two pairs of IR decoys and background respectively in the same field of view of the seeker's optical system simultaneously. An IR imaging fiber bundle as the focal plane of the projection optical system was used to compound the target, decoys and background. The compound scene was projected to the seeker by the projection optical system. In IR imaging channel, IR scene was generated by an optical film chip as a visible to thermal transducer which was placed in a vacuum cell. The simulated temperature range of IR scene could be from room temperature to 430K.The thin film transducer had 512×512 pixels. Its frame rate could reach to 100Hz. Light sources with high equivalent black body temperature were adopted in IR target and decoy channels. The size and the radiation intensity of the IR point target and decoys could be controlled by pin holes and attenuators. The point target and decoys driven by high precise motors could travel through the whole instantaneous field of view of the seeker's optical system. Two pairs of decoys could move away from the center to the edge of the instantaneous field of view. The highest simulated black body temperature of the point source was 1200K.

  9. A Ground Systems Architecture Transition for A Distributed Operations System

    NASA Technical Reports Server (NTRS)

    Sellers, Donna; Bailey, Darrell (Technical Monitor)

    2002-01-01

    The Marshall Space Flight Center (MSFC) Ground Systems Department (GSD) recently undertook an architecture change in the product line that serves the ISS program. As a result, the architecture tradeoffs between data system product lines that serve remote users versus those that serve control center flight control teams were explored extensively. This paper describes the resulting architecture that will be used in the ISS payloads program, and the resulting functional breakdown of the products that support that architecture. It also describes the lessons learned from the path that was followed, as a migration of products cause the need to reevaluate the allocation of functions across the architecture. The result is a set of innovative ground system solutions that is scalable so it can support facilities of wide-ranging sizes, from a small site up to large control centers. Effective use of system automation, custom components, design optimization for data management, data storage, data transmissions, and advanced local and wide area networking architectures, plus the effective use of Commercial-Off-The-Shelf (COTS) products, provides flexible Remote Ground System options that can be tailored to the needs of each user. This paper offers a description of the efficiency and effectiveness of the Ground Systems architectural options that have been implemented, and includes successful implementation examples and lessons learned.

  10. A Ground Systems Architecture Transition for a Distributed Operations System

    NASA Technical Reports Server (NTRS)

    Sellers, Donna; Pitts, Lee; Bryant, Barry

    2003-01-01

    The Marshall Space Flight Center (MSFC) Ground Systems Department (GSD) recently undertook an architecture change in the product line that serves the ISS program. As a result, the architecture tradeoffs between data system product lines that serve remote users versus those that serve control center flight control teams were explored extensively. This paper describes the resulting architecture that will be used in the International Space Station (ISS) payloads program, and the resulting functional breakdown of the products that support this architecture. It also describes the lessons learned from the path that was followed, as a migration of products cause the need to reevaluate the allocation of functions across the architecture. The result is a set of innovative ground system solutions that is scalable so it can support facilities of wide-ranging sizes, from a small site up to large control centers. Effective use of system automation, custom components, design optimization for data management, data storage, data transmissions, and advanced local and wide area networking architectures, plus the effective use of Commercial-Off-The-Shelf (COTS) products, provides flexible Remote Ground System options that can be tailored to the needs of each user. This paper offers a description of the efficiency and effectiveness of the Ground Systems architectural options that have been implemented, and includes successful implementation examples and lessons learned.

  11. A Geo-Distributed System Architecture for Different Domains

    NASA Astrophysics Data System (ADS)

    Moßgraber, Jürgen; Middleton, Stuart; Tao, Ran

    2013-04-01

    The presentation will describe work on the system-of-systems (SoS) architecture that is being developed in the EU FP7 project TRIDEC on "Collaborative, Complex and Critical Decision-Support in Evolving Crises". In this project we deal with two use-cases: Natural Crisis Management (e.g. Tsunami Early Warning) and Industrial Subsurface Development (e.g. drilling for oil). These use-cases seem to be quite different at first sight but share a lot of similarities, like managing and looking up available sensors, extracting data from them and annotate it semantically, intelligently manage the data (big data problem), run mathematical analysis algorithms on the data and finally provide decision support on this basis. The main challenge was to create a generic architecture which fits both use-cases. The requirements to the architecture are manifold and the whole spectrum of a modern, geo-distributed and collaborative system comes into play. Obviously, one cannot expect to tackle these challenges adequately with a monolithic system or with a single technology. Therefore, a system architecture providing the blueprints to implement the system-of-systems approach has to combine multiple technologies and architectural styles. The most important architectural challenges we needed to address are 1. Build a scalable communication layer for a System-of-sytems 2. Build a resilient communication layer for a System-of-sytems 3. Efficiently publish large volumes of semantically rich sensor data 4. Scalable and high performance storage of large distributed datasets 5. Handling federated multi-domain heterogeneous data 6. Discovery of resources in a geo-distributed SoS 7. Coordination of work between geo-distributed systems The design decisions made for each of them will be presented. These developed concepts are also applicable to the requirements of the Future Internet (FI) and Internet of Things (IoT) which will provide services like smart grids, smart metering, logistics and

  12. Gestalt-based integrity of distributed networked systems

    NASA Astrophysics Data System (ADS)

    Sapaty, Peter

    2009-09-01

    The project aims at obtaining high integrity and goal orientation of distributed dynamic systems, which may include multiple wireless sensors and mobile robots, as well as humans. The technology developed is based on the ideology of gestalt, where the whole is considered first, dominating over parts and dynamically defining their role and even existence in the context of changing goals and states of environment. Spatial mission scenarios, which may be created on the fly, are represented in a compact non-agents form collectively executed by the intelligent network of interpreters embedded into sensitive points of the system to be managed. The approach allows us to provide effective asymmetric runtime solutions to complex asymmetric problems and fulfill objectives in unpredictable environments, paving the way to massive robotization of advanced civil and military systems. The paper covers a broad spectrum of topics from philosophy and ideology to system management, to novel distributed control technology and its implementation, and to a variety of important applications. The paradigm described may be considered as the first implementation of the idea of gestalt to management of open distributed systems, as well as the first globally programmable universal super-machine dynamically covering distributed worlds and operating with both information and matter without any central resources.

  13. Distributed LQR control for discrete-time homogeneous systems

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Zhang, Fangfang; Han, Chunyan

    2016-11-01

    This paper investigates the distributed linear quadratic regulation (LQR) controller design method for discrete-time homogeneous scalar systems. Based on the optimal centralised control theory, the existence condition for distributed optimal controller is firstly proposed. It shows that the globally optimal distributed controller is dependent on the structure of the penalty matrix. Such results can be used in consensus problems and used to find under which communication topology (may not be an all-to-all form) the optimal distributed controller exists. When the proposed condition cannot hold, a suboptimal design method with the aid of the decomposition of discrete algebraic Riccati equations and robustness of local controllers is proposed. The computation complexity and communication load for each subsystem are only dependent on the number of its neighbours.

  14. The period ratio distribution of Kepler's candidate multiplanet systems

    NASA Astrophysics Data System (ADS)

    Steffen, Jason H.; Hwang, Jason A.

    2015-04-01

    We calculate and analyse the distribution of period ratios observed in systems of Kepler exoplanet candidates including studies of both adjacent planet pairs and all planet pairs. These distributions account for both the geometrical bias against detecting more distant planets and the effects of incompleteness due to planets missed by the data reduction pipeline. In addition to some of the known features near first-order mean-motion resonances (MMRs), there is a significant excess of planet pairs with period ratios near 2.2. The statistical significance of this feature is assessed using Monte Carlo simulation. We also investigate the distribution of period ratios near first-order MMR and compare different quantities used to measure this distribution. We find that beyond period ratios of ˜2.5, the distribution of all period ratios follows a power law with an exponent -1.26 ± 0.05. We discuss implications that these results may have on the formation and dynamical evolution of Kepler-like planetary systems-systems of sub-Neptune/super-Earth planets with relatively short orbital periods.

  15. Measurement of the temperature distribution inside the power cable using distributed temperature system

    NASA Astrophysics Data System (ADS)

    Jaros, Jakub; Liner, Andrej; Papes, Martin; Vasinek, Vladimir; Mach, Veleslav; Hruby, David; Kajnar, Tomas; Perecar, Frantisek

    2015-01-01

    Nowadays, the power cables are manufactured to fulfill the following condition - the highest allowable temperature of the cable during normal operation and the maximum allowable temperature at short circuit conditions cannot exceed the condition of the maximum allowable internal temperature. The distribution of the electric current through the conductor leads to the increase of the amplitude of electrons in the crystal lattice of the cables material. The consequence of this phenomenon is the increase of friction and the increase of collisions between particles inside the material, which causes the temperature increase of the carrying elements. The temperature increase is unwanted phenomena, because it is causing losses. In extreme cases, the long-term overload leads to the cable damaging or fire. This paper deals with the temperature distribution measurement inside the power cables using distributed temperature system. With cooperation with Kabex company, the tube containing optical fibers was installed into the center of power cables. These fibers, except telecommunications purposes, can be also used as sensors in measurements carrying out with distributed temperature system. These systems use the optical fiber as a sensor and allow the continual measurement of the temperature along the whole cable in real time with spatial resolution 1 m. DTS systems are successfully deployed in temperature measurement applications in industry areas yet. These areas include construction, drainage, hot water etc. Their advantages are low cost, resistance to electromagnetic radiation and the possibility of real time monitoring at the distance of 8 km. The location of the optical fiber in the center of the power cable allows the measurement of internal distribution of the temperature during overloading the cable. This measurement method can be also used for prediction of short-circuit and its exact location.

  16. 49 CFR 192.623 - Maximum and minimum allowable operating pressure; Low-pressure distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... distribution systems. (a) No person may operate a low-pressure distribution system at a pressure high enough to...) No person may operate a low pressure distribution system at a pressure lower than the...

  17. Recommendation System Based On Association Rules For Distributed E-Learning Management Systems

    NASA Astrophysics Data System (ADS)

    Mihai, Gabroveanu

    2015-09-01

    Traditional Learning Management Systems are installed on a single server where learning materials and user data are kept. To increase its performance, the Learning Management System can be installed on multiple servers; learning materials and user data could be distributed across these servers obtaining a Distributed Learning Management System. In this paper is proposed the prototype of a recommendation system based on association rules for Distributed Learning Management System. Information from LMS databases is analyzed using distributed data mining algorithms in order to extract the association rules. Then the extracted rules are used as inference rules to provide personalized recommendations. The quality of provided recommendations is improved because the rules used to make the inferences are more accurate, since these rules aggregate knowledge from all e-Learning systems included in Distributed Learning Management System.

  18. Multi-kw dc power distribution system study program

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.; Krausz, A.

    1974-01-01

    The first phase of the Multi-kw dc Power Distribution Technology Program is reported and involves the test and evaluation of a technology breadboard in a specifically designed test facility according to design concepts developed in a previous study on space vehicle electrical power processing, distribution, and control. The static and dynamic performance, fault isolation, reliability, electromagnetic interference characterisitics, and operability factors of high distribution systems were studied in order to gain a technology base for the use of high voltage dc systems in future aerospace vehicles. Detailed technical descriptions are presented and include data for the following: (1) dynamic interactions due to operation of solid state and electromechanical switchgear; (2) multiplexed and computer controlled supervision and checkout methods; (3) pulse width modulator design; and (4) cable design factors.

  19. A hierarchical distributed control model for coordinating intelligent systems

    NASA Technical Reports Server (NTRS)

    Adler, Richard M.

    1991-01-01

    A hierarchical distributed control (HDC) model for coordinating cooperative problem-solving among intelligent systems is described. The model was implemented using SOCIAL, an innovative object-oriented tool for integrating heterogeneous, distributed software systems. SOCIAL embeds applications in 'wrapper' objects called Agents, which supply predefined capabilities for distributed communication, control, data specification, and translation. The HDC model is realized in SOCIAL as a 'Manager'Agent that coordinates interactions among application Agents. The HDC Manager: indexes the capabilities of application Agents; routes request messages to suitable server Agents; and stores results in a commonly accessible 'Bulletin-Board'. This centralized control model is illustrated in a fault diagnosis application for launch operations support of the Space Shuttle fleet at NASA, Kennedy Space Center.

  20. Distributed Frequency Control of Prosumer-Based Electric Energy Systems

    SciTech Connect

    Nazari, MH; Costello, Z; Feizollahi, MJ; Grijalva, S; Egerstedt, M

    2014-11-01

    In this paper, we propose a distributed frequency regulation framework for prosumer-based electric energy systems, where a prosumer (producer-consumer) is defined as an intelligent agentwhich can produce, consume, and/or store electricity. Despite the frequency regulators being distributed, stability can be ensured while avoiding inter-area oscillations using a limited control effort. To achieve this, a fully distributed one-step model-predictive control protocol is proposed and analyzed, whereby each prosumer communicates solely with its neighbors in the network. The efficacy of the proposed frequency regulation framework is shown through simulations on two real-world electric energy systems of different scale and complexity. We show that prosumers can indeed bring frequency and power deviations to their desired values after small perturbations.

  1. A telemedicine distributed system for cooperative medical diagnosis.

    PubMed Central

    Gómez, E. J.; del Pozo, F.; Quiles, J. A.; Sanz, M.; Rahms, H.; Vaquero, J. J.; Cano, P.; Hernando, M. E.; Arredondo, M. T.

    1994-01-01

    Telemedicine is changing the classical form of health care delivery, dramatically increasing the number of new applications in which some type of distributed synchronous cooperation between health care professionals is required. This paper presents the design and development of a telemedicine distributed system for cooperative medical diagnosis based on two new approaches: 1) a distributed layered architecture specially designed to add synchronous computer supported cooperative work features either to new or existing medical applications; 2) the definition of a methodological procedure to design graphical user interfaces for telemedicine cooperative working scenarios. The cooperative work is supported by a collaborative toolkit that provides telepointing, window sharing, coordination and synchronization. Finally, we have implemented and installed the telemedicine system in clinical practice between two hospitals, providing teleconferencing facilities for cooperative decision support in haemodynamics studies. This specific implementation and a preliminary evaluation were accomplished under the Research Project FEST "Framework for European Services in Telemedicine" funded by the EU AIM Programme. PMID:7949965

  2. Image sequence analysis workstation for multipoint motion analysis

    NASA Astrophysics Data System (ADS)

    Mostafavi, Hassan

    1990-08-01

    This paper describes an application-specific engineering workstation designed and developed to analyze motion of objects from video sequences. The system combines the software and hardware environment of a modem graphic-oriented workstation with the digital image acquisition, processing and display techniques. In addition to automation and Increase In throughput of data reduction tasks, the objective of the system Is to provide less invasive methods of measurement by offering the ability to track objects that are more complex than reflective markers. Grey level Image processing and spatial/temporal adaptation of the processing parameters is used for location and tracking of more complex features of objects under uncontrolled lighting and background conditions. The applications of such an automated and noninvasive measurement tool include analysis of the trajectory and attitude of rigid bodies such as human limbs, robots, aircraft in flight, etc. The system's key features are: 1) Acquisition and storage of Image sequences by digitizing and storing real-time video; 2) computer-controlled movie loop playback, freeze frame display, and digital Image enhancement; 3) multiple leading edge tracking in addition to object centroids at up to 60 fields per second from both live input video or a stored Image sequence; 4) model-based estimation and tracking of the six degrees of freedom of a rigid body: 5) field-of-view and spatial calibration: 6) Image sequence and measurement data base management; and 7) offline analysis software for trajectory plotting and statistical analysis.

  3. Iron and copper release in drinking-water distribution systems.

    PubMed

    Shi, Baoyou; Taylor, James S

    2007-09-01

    A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature.

  4. System and Method for Monitoring Distributed Asset Data

    NASA Technical Reports Server (NTRS)

    Gorinevsky, Dimitry (Inventor)

    2015-01-01

    A computer-based monitoring system and monitoring method implemented in computer software for detecting, estimating, and reporting the condition states, their changes, and anomalies for many assets. The assets are of same type, are operated over a period of time, and outfitted with data collection systems. The proposed monitoring method accounts for variability of working conditions for each asset by using regression model that characterizes asset performance. The assets are of the same type but not identical. The proposed monitoring method accounts for asset-to-asset variability; it also accounts for drifts and trends in the asset condition and data. The proposed monitoring system can perform distributed processing of massive amounts of historical data without discarding any useful information where moving all the asset data into one central computing system might be infeasible. The overall processing is includes distributed preprocessing data records from each asset to produce compressed data.

  5. Simulating fail-stop in asynchronous distributed systems

    NASA Technical Reports Server (NTRS)

    Sabel, Laura; Marzullo, Keith

    1994-01-01

    The fail-stop failure model appears frequently in the distributed systems literature. However, in an asynchronous distributed system, the fail-stop model cannot be implemented. In particular, it is impossible to reliably detect crash failures in an asynchronous system. In this paper, we show that it is possible to specify and implement a failure model that is indistinguishable from the fail-stop model from the point of view of any process within an asynchronous system. We give necessary conditions for a failure model to be indistinguishable from the fail-stop model, and derive lower bounds on the amount of process replication needed to implement such a failure model. We present a simple one-round protocol for implementing one such failure model, which we call simulated fail-stop.

  6. Distributed photovoltaic systems: Utility interface issues and their present status

    NASA Technical Reports Server (NTRS)

    Hassan, M.; Klein, J.

    1981-01-01

    Major technical issues involving the integration of distributed photovoltaics (PV) into electric utility systems are defined and their impacts are described quantitatively. An extensive literature search, interviews, and analysis yielded information about the work in progress and highlighted problem areas in which additional work and research are needed. The findings from the literature search were used to determine whether satisfactory solutions to the problems exist or whether satisfactory approaches to a solution are underway. It was discovered that very few standards, specifications, or guidelines currently exist that will aid industry in integrating PV into the utility system. Specific areas of concern identified are: (1) protection, (2) stability, (3) system unbalance, (4) voltage regulation and reactive power requirements, (5) harmonics, (6) utility operations, (7) safety, (8) metering, and (9) distribution system planning and design.

  7. Modeling contaminant propagation in drinking-water distribution systems

    SciTech Connect

    Clark, R.M.; Grayman, W.M.; Males, R.M.; Hess, A.F.

    1993-01-01

    The Safe Drinking Water Act and its Amendments (SDWAA) will pose a massive challenge for the drinking-water industry in the United States. As the SDWAA regulations reach implementation, increasing effort will be devoted to understanding the factors causing deterioration of water quality between treatment and consumption. A cooperative study involving the U.S. EPA, the University of Michigan, and the South Central Connecticut Regional Water Authority (RWA) demonstrated and validated the use of modeling techniques in the RWA distribution system. Models are used to predict the propagation of chlorine residual in one portion of the RWA system. It is found that residuals varied widely both spatially and temporally. Long residence times in storage tanks caused residual disinfection concentrations to be low or nonexistent during discharge cycles. It was found that system operation has a significant effect on the distribution and concentration of chlorine residuals in the system.

  8. Direct broadcast satellite receiver system with optical distribution network

    NASA Astrophysics Data System (ADS)

    Kemery, S. M.; Daryoush, A. S.; Herczfeld, P. R.

    1986-01-01

    With recent developments in fiber optic communications and optical distribution networks, short haul optical communications becomes an economical alternative to conventional cable TV systems. This paper presents a system design for a direct broadcast satellite receiver system with a fiber optic distribution network based on the reception of Ku-band signals from ANIK C2, a Canadian direct broadcast satellite. Such a system is proposed for the first time and can address small communities in remote areas. Theoretical power budget calculations predict that 37 subscribers can access 128 television channels using a 3 ft reflector dish antenna. To implement such a design, a number of components that are not commercially available are custom designed.

  9. High performance distributed feedback fiber laser sensor array system

    NASA Astrophysics Data System (ADS)

    He, Jun; Li, Fang; Xu, Tuanwei; Wang, Yan; Liu, Yuliang

    2009-11-01

    Distributed feedback (DFB) fiber lasers have their unique properties useful for sensing applications. This paper presents a high performance distributed feedback (DFB) fiber laser sensor array system. Four key techniques have been adopted to set up the system, including DFB fiber laser design and fabrication, interferometric wavelength shift demodulation, digital phase generated carrier (PGC) technique and dense wavelength division multiplexing (DWDM). Experimental results confirm that a high dynamic strain resolution of 305 fɛ/√Hz (@ 1 kHz) has been achieved by the proposed sensor array system. And the multiplexing of eight channel DFB fiber laser sensor array has been demonstrated. The proposed DFB fiber laser sensor array system is suitable for ultra-weak signal detection, and has potential applications in the field of petroleum seismic explorations, earthquake prediction, and security.

  10. Building Blocks for Distributed Information Systems in Hospitals

    PubMed Central

    Rutt, Thomas E.

    1987-01-01

    In order to provide a consistent view of work functions which can be supported by successive releases of hospital information systems, a hospital business model was developed. The business model describes potential system functions along with their data access needs. This model was used to determine an optimal set of mutually exclusive logical databases. These logical databases are seeds around which design of distributed systems should be based. The logical databases derived by this work can be used as a starting point for defining application protocol standards for hospital system interface transactions.

  11. Solar window collection and distribution module system. Final performance report

    SciTech Connect

    Not Available

    1985-01-01

    The construction and monitoring of a solar window collection and distribution system are presented. One complete window module was purchased and assembled, including: the glass, the window frames, sealants, grills, vents and a mechanical damper device. Monitoring of the system operation was limited to measuring inside air temperature, outside air temperature, and circulation temperatures through the window module systems, as well as the actual tinted glass surface temperature. The system has produced a reduction in glare, fading of furniture, and control of solar gains to a building structure.

  12. IEA/SPS 500 kW distributed collector system

    NASA Technical Reports Server (NTRS)

    Neumann, T. W.; Hartman, C. D.

    1980-01-01

    Engineering studies for an International Energy Agency project for the design and construction of a 500 kW solar thermal electric power generation system of the distributed collector system (DCS) type are reviewed. The DCS system design consists of a mixed field of parabolic trough type solar collectors which are used to heat a thermal heat transfer oil. Heated oil is delivered to a thermocline storage tank from which heat is extracted and delivered to a boiler by a second heat transfer loop using the same heat transfer oil. Steam is generated in the boiler, expanded through a steam turbine, and recirculated through a condenser system cooled by a wet cooling tower.

  13. On the Interconnection of Incompatible Solid Finite Element Meshes Using Multipoint Constraints

    NASA Technical Reports Server (NTRS)

    Fox, G. L.

    1985-01-01

    Incompatible meshes, i.e., meshes that physically must have a common boundary, but do not necessarily have coincident grid points, can arise in the course of a finite element analysis. For example, two substructures may have been developed at different times for different purposes and it becomes necessary to interconnect the two models. A technique that uses only multipoint constraints, i.e., MPC cards (or MPCS cards in substructuring), is presented. Since the method uses only MPC's, the procedure may apply at any stage in an analysis; no prior planning or special data is necessary.

  14. CLASSIFICATION OF THE MGR SUBSURFACE WATER DISTRIBUTION SYSTEM

    SciTech Connect

    R. Garrett

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface water distribution system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

  15. CLASSIFICATION OF THE MGR SUBSURFACE ELECTRICAL DISTRIBUTION SYSTEM

    SciTech Connect

    R.J. Garrett

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface electrical distribution system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333PY ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

  16. Master Clock and Time-Signal-Distribution System

    NASA Technical Reports Server (NTRS)

    Tjoelker, Robert; Calhoun, Malcolm; Kuhnle, Paul; Sydnor, Richard; Lauf, John

    2007-01-01

    A timing system comprising an electronic master clock and a subsystem for distributing time signals from the master clock to end users is undergoing development to satisfy anticipated timing requirements of NASA s Deep Space Network (DSN) for the next 20 to 30 years. This system has a modular, flexible, expandable architecture that is easier to operate and maintain than the present frequency and timing subsystem (FTS).

  17. ACTORS: A model of concurrent computation in distributed systems

    SciTech Connect

    Agha, G.

    1986-01-01

    The transition from sequential to parallel computation is an area of critical concern in today's computer technology, particularly in architecture, programming languages, systems, and artificial intelligence. This book addresses issues in concurrency, and by producing both a syntactic definition and a denotational model of Hewitt's actor paradigm - a model of computation specifically aimed at constructing and analyzing distributed large-scale parallel systems - it advances the understanding of parallel computation.

  18. Automated Energy Distribution and Reliability System (AEDR): Final Report

    SciTech Connect

    Buche, D. L.

    2008-07-01

    This report describes Northern Indiana Public Service Co. project efforts to develop an automated energy distribution and reliability system. The purpose of this project was to implement a database-driven GIS solution that would manage all of the company's gas, electric, and landbase objects.

  19. Chandrasekhar equations and computational algorithms for distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Ito, K.; Powers, R. K.

    1984-01-01

    The Chandrasekhar equations arising in optimal control problems for linear distributed parameter systems are considered. The equations are derived via approximation theory. This approach is used to obtain existence, uniqueness, and strong differentiability of the solutions and provides the basis for a convergent computation scheme for approximating feedback gain operators. A numerical example is presented to illustrate these ideas.

  20. The Accumulation of Radioactive Contaminants in Drinking Water Distribution Systems

    EPA Science Inventory

    The accumulation of trace contaminants in drinking water distribution systems has been documented and the subsequent release of the contaminants back to the water is a potential exposure pathway. Radioactive contaminants are of particular concern because of their known health eff...