Science.gov

Sample records for distributed uhv system

  1. Distributed UHV system for the folded tandem ion accelerator facility at BARC

    NASA Astrophysics Data System (ADS)

    Gupta, S. K.; Agarwal, A.; Singh, S. K.; Basu, A.; P, Sapna; Sarode, S. P.; Singh, V. P.; Subrahmanyam, N. B. V.; Bhatt, J. P.; Pol, S. S.; Raut, P. J.; Ware, S. V.; Singh, P.; Choudhury, R. K.; Kailas, S.

    2008-05-01

    The 6 MV Folded Tandem Ion Accelerator (FOTIA) Facility at the Nuclear Physics Division, BARC is operational and accelerated beams of both light and heavy ions are being used extensively for basic and applied research. An average vacuum of the order of 10-8-10-9 Torr is maintained for maximum beam transmission and minimum beam energy spreads. The FOTIA vacuum system comprises of about 55 meter long, 100 mm diameter beam lines including various diagnostic devices, two accelerating tubes and four narrow vacuum chambers. The cross sections of the vacuum chambers are 14mm × 24mm for 180°, 38mm × 60mm and 19 × 44 mm for the and 70° & 90° bending magnets and Switching chambers respectively. All the beam line components are UHV compatible, fabricated from stainless steel 304L grade material fitted with metal gaskets. The total volume ~5.8 × 105 cm3 and surface area of 4.6 × 104 cm2, interspersed with total 18 pumping stations. The accelerating tubes are subjected to very high voltage gradient, 20.4 kV/cm, which requires a hydrocarbon free and clean vacuum for smooth operation of the accelerator. Vacuum interlocks are provided to various devices for safe operation of the accelerator. Specially designed sputter ion pumps for higher environmental pressure of 8 atmospheres are used to pump the accelerating tubes and the vacuum chamber for the 180° bending magnet. Fast acting valves are provided for isolating main accelerator against accidental air rush from rest of the beam lines. All the vacuum readings are displayed locally and are also available remotely through computer interface to the Control Room. Vacuum system details are described in this paper.

  2. Optimization of drift bias in an UHV based pulsed positron beam system

    SciTech Connect

    Anto, C. Varghese; Rajaraman, R.; Rao, G. Venugopal; Abhaya, S.; Parimala, J.; Amarendra, G.

    2012-06-05

    We report here the design of ultra high vacuum (UHV) compatible pulsed positron beam lifetime system, which combines the principles of a conventional slow positron beam and RF based pulsing scheme. The mechanical design and construction of the UHV system to house the beam has been completed and it has been tested for a vacuum of {approx} 10{sup -10} mbar. The voltages applied to the drift tube as a function of positron energies have been optimized using SIMION.

  3. a Uhv Compatible SQUID Magnetometer System for Investigations in Surface, Interface, and Thin Film Magnetism

    NASA Astrophysics Data System (ADS)

    Spagna, Stefano

    The magnetic properties of Co thin films on silicon and magnetite single crystal substrates grown by electron beam evaporation were studied in situ in UHV using a superconducting quantum interference device magnetometer (UHVSQM). In this system, freshly deposited thin film samples from a separate molecular beam epitaxy (MBE) facility, were transported into the UHVSQM for magnetic characterization without breaking vacuum. The combination of the extremely high sensitivity of the SQUID for magnetic measurements with UHV surface analysis techniques offers the unique capability for films to be prepared, processed, and characterized repeatedly without substantial contamination. Magnetization isotherms as function of oxygen exposure on polycrystalline thin ferromagnetic (FM) Co layers indicate that the magnetic properties of these materials are profoundly altered as a result of oxidation and atmospheric contamination. In addition, field-cooled hysteresis loops performed at low temperatures indicate that the antiferromagnetic (AF) Co-oxide layer that result from the oxidation process is responsible for an induced exchange anisotropy in the FM Co films. The data indicates that interfacial roughness and non-uniform coupling across the interface may cause the AF to break up into a domain structure analogous to the one found in bulk FM materials. The resulting AF magnetic structure is apparently dependent on the competition between destabilizing forces at the interface when the FM layer moment's direction is reversed and stabilizing coercive forces within the AF domains. During the course of this research, we also investigated the effect of clean and oxidized Co layers on the magnetic properties of oriented single crystal rm Fe_3O_4 films. These experiments were aimed in gaining an understanding of the underlying mechanism responsible for the large increase in coercivity rm (H_{c}), and induced uniaxial anisotropy exhibited by this system as a result of the Co coverage. A

  4. Challenges and Advances in Instrumentation of UHV LT Multi-Probe SPM System

    NASA Astrophysics Data System (ADS)

    Wang, Zhouhang

    The progress of nanoscience and nanotechnology can be realized only through continued advances and utilization of instruments and techniques for characterizing material properties and manipulating material and device at nanoscale. The UHV LT Multi-Probe SPM system with high resolution SEM has been developed to meet such challenges. This integrated instrument bridges dimensions from the centimeter to atomic scale, and provides an unprecedented platform for local, non-destructive transport measurements and for building, manipulating and function-testing complex nanoelectronics and nanoscale machineries. It also enables combining many different techniques for characterizing sample conductance, topography, chemical, optical or magnetic properties with complementary information at the same position or on the same nanodevice. Design and development of such complex systems pose many issues and challenges. This chapter will discuss some of the issues faced, solutions reached and advances made. Examples include: (1) Disturbance by magnetic material and magnetic field of SEM imaging and coordination of SEM/SPM position, and their influence on and disturbance of SAM spectra and SAM mapping. The design and use of non-magnetic motors for multi-probe modules will be presented and discussed. (2) Tip holder and sample holder design for easy handling, better mechanical stability over the temperature range and better thermal contact and the versatility of the sample holder with multiple contacts. (3) Use of optical fiber as one of the probe modules, and positioning of the fiber probe. CL spectra and CL mapping results will be presented.

  5. UHV piezoelectric translator

    SciTech Connect

    Oversluizen, T.; Watson, G.

    1985-01-01

    A UHV compatible piezoelectric translator has been developed to correct for angular misalignments in the crysals of a UHV x-ray monochromator. The unit is small, bakeable to 150/sup 0/C, and uses only ceramic materials for insulation. We report on the construction details, vacuum compatibility, mechanical properties, and uses of the device.

  6. Application of a power line maintenance information system using OPGW to the Nishi-Gunma UHV line

    SciTech Connect

    Ooura, K.; Kanemaru, K.; Matsubara, R.; Ibuki, S.

    1995-01-01

    Tokyo Electric Power Company, Inc. began operation of the Nishi-Gunma UHV trunk line, the first 1,000 kV-designed power line in Japan, in April, 1992. This line is expected to be the key line in a major trunk-line system that is being developed. It traverses high-altitude mountainous areas subject to severe environmental and meteorological conditions for a long distance. A system using Composite Fiber-optic Overhead Ground Wire (OPGW) is constructed to obtain precise information on this line for maintenance purposes. This system comprises three major functions; (1) meteorological and facility`s monitoring for gathering meteorological data on such elements as winds, and icing and snow accretion, and for evaluating the corresponding reaction of the components such as conductor tension, and strain In the tower structure, (2) Industrial TV (ITV) monitoring for visual observation of weather, surrounding conditions and site facilities, and (3) fault section location for pinpointing faults quickly and determining the maintenance office that should respond to the faults. This Is done by estimating the fault section accurately around the boundaries of the maintenance jurisdictions. This paper describes the development of these functions and results obtained from practical operation.

  7. Small UHV compatible hyperthermal oxygen atom generator

    NASA Technical Reports Server (NTRS)

    Outlaw, Ronald A. (Inventor); Davison, Mark R. (Inventor)

    1994-01-01

    A high purity, hyperthermal, continuous beam atomic oxygen source capable of retrofitting to existing UHV systems has been developed. The instrument complements a general system capability, while its small size and simplicity of design permits tailoring the instrument for most experimental geometries. The flux level presently available is near 1 x 10 (exp 14) cm(exp -2)s(exp -1)(3P) but may be extended toward the theoretical limit of 3x10(exp 15 cm(exp -2)s(exp -1). The energy distribution of the emitted neutrals shows that the mean kinetic energy is about the same as observed for the ions or about 4 eV. The energy of the oxygen atoms may be substantially reduced for other applications by collision with a temperature controlled, non-reactive surface (with a concomitant spread in the energy distribution).

  8. Full membrane spanning self-assembled monolayers as model systems for UHV-based studies of cell-penetrating peptides

    SciTech Connect

    Franz, Johannes; Graham, Daniel J.; Baio, Joe E.; Lelle, Marco; Peneva, Kalina; Müllen, Klaus; Castner, David G.; Weidner, Tobias

    2015-03-01

    Biophysical studies of the interaction of peptides with model membranes provide a simple yet effective approach to understand the transport of peptides and peptide based drug carriers across the cell membrane. Therein, the authors discuss the use of self-assembled monolayers fabricated from the full membrane-spanning thiol (FMST) 3-((14-((4'-((5-methyl-1-phenyl-35-(phytanyl)oxy-6,9,12,15,18,21,24,27,30,33,37-undecaoxa-2,3-dithiahenpentacontan-51-yl)oxy)-[1,1'-biphenyl]-4-yl)oxy)tetradecyl)oxy)-2-(phytanyl)oxy glycerol for ultrahigh vacuum (UHV) based experiments. UHV-based methods such as electron spectroscopy and mass spectrometry can provide important information about how peptides bind and interact with membranes, especially with the hydrophobic core of a lipid bilayer. Moreover, near-edge x-ray absorption fine structure spectra and x-ray photoelectron spectroscopy (XPS) data showed that FMST forms UHV-stable and ordered films on gold. XPS and time of flight secondary ion mass spectrometry depth profiles indicated that a proline-rich amphipathic cell-penetrating peptide, known as sweet arrow peptide is located at the outer perimeter of the model membrane.

  9. Testing facilities for developing UHV equipments

    SciTech Connect

    Yamamoto, M.; Honda, M.

    1982-07-01

    The testing facilities of UHV (Ultra High Voltage) laboratory are described in this paper. The voltage rating of testing facilities and dimensions of the laboratory for developing UHV substation equipments, especially transformers and gas insulated equipments, are discussed on the basis of research and development experiencies of UHV equipment manufacture.

  10. Simple, efficient UHV manipulator

    SciTech Connect

    Thiel, P.A.; Anderegg, J.W.

    1984-10-01

    A simple manipulator is described for use in ultrahigh vacuum. Unhindered rotation within vacuum is provided by a commercial differentially pumped adapter to which the entire XYZ stage is attached. The combination of movements provided by the XYZ stage, the rotating vacuum flange, and a gimbal permits alignment of the sample with any of the peripheral view ports. The resistively heated sample support, mounted through a cold finger, permits rapid variation of sample temperature from several hundred degrees Kelvin to near cryogenic. It is anticipated that this design could be easily used with many existing types of commercial vacuum systems, with the consequent advantage of increased ease and simplicity of both mechanical motion and cryogenic cooling.

  11. FRIB cryogenic distribution system

    NASA Astrophysics Data System (ADS)

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

    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.

  12. Video Distribution Systems.

    ERIC Educational Resources Information Center

    Davoust, David

    1994-01-01

    Describes video distribution systems as a way of giving control of all monitors in a classroom to the teacher. Examples of their use are given, including distribution in language labs and distribution from a media lab to classrooms throughout a school building; and information about five vendors is included. (LRW)

  13. Smart distribution systems

    DOE PAGESBeta

    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

  14. 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.

  15. 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.

  16. THERMAL DISTRIBUTION SYSTEM EXPERIMENT

    SciTech Connect

    KRAJEWSKI,R.F.; ANDREWS,J.W.; WEI,G.

    1999-09-01

    A laboratory experiment has been conducted which tests for the effects of distribution system purging on system Delivery Effectiveness (DE) as defined in ASHRAE 152P. The experiment is described in its configuration, instrumentation, and data acquisition system. Data gathered in the experiment is given and discussed. The results show that purging of the distribution system alone does not offer any improvement of the system DE. Additional supporting tests were conducted regarding experimental simulations of buffer zones and bare pipe and are also discussed.

  17. 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.

  18. 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.

  19. Distributed Computerized Catalog System

    NASA Technical Reports Server (NTRS)

    Borgen, Richard L.; Wagner, David A.

    1995-01-01

    DarkStar Distributed Catalog System describes arbitrary data objects in unified manner, providing end users with versatile, yet simple search mechanism for locating and identifying objects. Provides built-in generic and dynamic graphical user interfaces. Design of system avoids some of problems of standard DBMS, and system provides more flexibility than do conventional relational data bases, or object-oriented data bases. Data-collection lattice partly hierarchical representation of relationships among collections, subcollections, and data objects.

  20. Design of a -1 MV dc UHV power supply for ITER NBI

    NASA Astrophysics Data System (ADS)

    Watanabe, K.; Yamamoto, M.; Takemoto, J.; Yamashita, Y.; Dairaku, M.; Kashiwagi, M.; Taniguchi, M.; Tobari, H.; Umeda, N.; Sakamoto, K.; Inoue, T.

    2009-05-01

    Procurement of a dc -1 MV power supply system for the ITER neutral beam injector (NBI) is shared by Japan and the EU. The Japan Atomic Energy Agency as the Japan Domestic Agency (JADA) for ITER contributes to the procurement of dc -1 MV ultra-high voltage (UHV) components such as a dc -1 MV generator, a transmission line and a -1 MV insulating transformer for the ITER NBI power supply. The inverter frequency of 150 Hz in the -1 MV power supply and major circuit parameters have been proposed and adopted in the ITER NBI. The dc UHV insulation has been carefully designed since dc long pulse insulation is quite different from conventional ac insulation or dc short pulse systems. A multi-layer insulation structure of the transformer for a long pulse up to 3600 s has been designed with electric field simulation. Based on the simulation the overall dimensions of the dc UHV components have been finalized. A surge energy suppression system is also essential to protect the accelerator from electric breakdowns. The JADA contributes to provide an effective surge suppression system composed of core snubbers and resistors. Input energy into the accelerator from the power supply can be reduced to about 20 J, which satisfies the design criteria of 50 J in total in the case of breakdown at -1 MV.

  1. Distributed Experiment Automation System

    NASA Astrophysics Data System (ADS)

    Lebedev, Gennadi

    2003-03-01

    Module based distributed system for controlling and automation scientific experiments were developed. System divides in five main layers: 1. Data processing and presentation modules, 2. Controllers - support primary command evaluation, data analysis and synchronization between Device Drivers. 3. Data Server. Provide real time data storage and management. 4. Device Drivers, support communication, preliminary signals acquisitions and control of peripheral devices. 5. Utility - batch processing, login, errors of execution handling, experimental data persistent storage and management, modules and devices monitoring, alarm state, remote components messaging and notification processing. System used networking (DCOM protocol) for communication between distributed modules. Configuration, modules parameters, data and commands links defined in scripting file (XML format). This modular structure allows great flexibility and extensibility as modules can be added and configured as required without any extensive programming.

  2. 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.

  3. Adaptive optics for ultra short pulsed lasers in UHV environment

    NASA Astrophysics Data System (ADS)

    Deneuville, Francois; Ropert, Laurent; Sauvageot, Paul; Theis, Sébastien

    2015-02-01

    ISP SYSTEM has developed an electro-mechanical deformable mirror compatible with Ultra High Vacuum environment, suitable for ultra short pulsed lasers. The design of the MD-AME deformable mirror is based on force application on numerous locations. μ-AME actuators are driven by stepper motors, and their patented special design allows controlling the force with a very high accuracy. Materials and assembly method have been adapted to UHV constraints and the performances were evaluated on a first application for a beam with a diameter of 250mm. A Strehl ratio above 0.9 was reached for this application. Optical aberrations up to Zernike order 5 can be corrected with a very low residual error as for standard MD-AME mirror. Amplitude can reach up to several hundreds of μm for low order corrections. Hysteresis is lower than 0.1% and linearity better than 99%. Contrary to piezo-electric actuators, the μ-AME actuators avoid print-through effects and they permit to keep the mirror shape stable even unpowered, providing a high resistance to electro-magnetic pulses. The deformable mirror design allows changing easily an actuator or even the membrane if needed, in order to improve the facility availability. They are designed for circular, square or elliptical aperture from 30mm up to 500mm or more, with incidence angle from 0° to 45°. They can be equipped with passive or active cooling for high power lasers with high repetition rate.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Distributed road assessment system

    SciTech Connect

    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.

  10. Nuclei growth kinetics during the nucleation of gold on UHV-cleaved mica substrates

    NASA Technical Reports Server (NTRS)

    Elliot, A. G.

    1974-01-01

    Measurements of crystalline sizes during nucleation of gold on mica surfaces cleaved in ultra-high vacuum (UHV) reveal the presence of symmetric, sharply peaked distributions which flatten and broaden with increasing nucleation time. When the number density of nuclei increases, the growth rate is suppressed. The time taken to reach a given size increases with increasing temperature when the nuclei are growing as isolated particles. When the nuclei are spaced so far that their diffusion fields overlap, then the time taken to reach a given size decreases with increasing temperature.

  11. 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.

  12. 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.

  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. Distribution system harmonic filter planning

    SciTech Connect

    Ortmeyer, T.H.; Hiyama, Takashi

    1996-10-01

    A planning methodology for distribution system harmonic filtering is proposed. The method is intended for use on radial distribution systems with no large harmonic sources. It is proposed that 60 hertz var planning be done first to allocate the var resources. Following this process, the harmonic filter planning can be readily accomplished. Characteristics of the distribution systems and the harmonic sources are exploited to provide a practical filter planning technique which is effective and efficient.

  16. 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.

  17. Distributed proximity sensor system

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1988-01-01

    The invention relates to sensors embedded on the surface of a robot hand, or other moving member. By distributing proximity sensors capable of detecting distances and angles to points on the surface of an object, information is obtained for achieving noncontacting shape and distance perception, i.e., for automatic determination of the object's shape, direction, and distance, as well as the orientation of the object relative to the robot hand or other moving member.

  18. Surface-sensitive UHV dielectric studies of nanoscale organic thin films: Adsorption, crystallization, and sublimation

    NASA Astrophysics Data System (ADS)

    Underwood, Jason M.

    Nanoscale systems are small collections of atoms or molecules, which as a result of their limited extent, show measurable thermodynamic deviations from bulk samples of the same species. The deviations may result from purely finite-size effects, or may be due to an increased significance of the interaction between the nanoscale system and its container. Ultra-thin (<100 nm) films of organic molecules adsorbed on surfaces afford unique opportunities to study the interplay of forces relevant to nanoscale physics. This thesis describes the development of a novel ultra-high vacuum apparatus to study the behavior of adsorbed polar molecules via dielectric spectroscopy (UHV-DS). Ultra-thin films are grown and characterized in-situ. The use of interdigitated electrode capacitors and a ratio-transformer bridge technique yields resolutions of ˜1 aF and ˜10-5 ppm in the capacitance and loss tangent, respectively. Typical sensitivity is 10 aF per monolayer at 80 K. Results are given for studies on water, methanol, and Cp* (a synthetic molecular rotor). The desorption event in the dielectric spectra is correlated with thermal desorption spectroscopy. During growth of methanol films, we observe partial crystallization for temperatures above ≳ 100 K. Crystallization is also observed upon heating glassy films grown at 80 K. Finally, we discuss UHV-DS as a probe for solid thin-film vapor pressure measurements, and show that our data on methanol compare favorably with those in the literature.

  19. A prototype Distributed Audit System

    SciTech Connect

    Banning, D.L.

    1993-08-01

    Security auditing systems are used to detect and assess unauthorized or abusive system usage. Historically, security audits were confined to a single computer system. Recent work examines ways of extending auditing to include heterogeneous groups of computers (distributed system). This paper describes the design and prototype development of a Distributed Audit System (DAS) which was developed with funding received from Lawrence Livermore Laboratory and through the Master`s thesis effort performed by the author at California State University, Long Beach. The DAS is intended to provide collection, transfer, and control of audit data on distributed, heterogeneous hosts.

  20. 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.

  1. 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…

  2. 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.

  3. An Einzel lens apparatus for deposition of levitated graphene on a substrate in UHV

    NASA Astrophysics Data System (ADS)

    Coppock, Joyce; Nagornykh, Pavel; McAdams, Ian; Kane, Bruce

    The goal of our research is to levitate a charged micron-scale graphene flake in an electrical AC quadrupole trap in ultra-high vacuum (UHV) in order to study its properties and dynamics while decoupled from any substrate. As a complement to the optical measurements that can be performed on the levitated flake, we are developing a method of depositing the same flake on a substrate, which can be removed from the system for further study using such probes as atomic force microscopy (AFM) and scanning tunneling microscopy (STM). As the flake is released from the trap and propelled toward the substrate, its trajectory will be controlled by an Einzel (electrostatic) lens to achieve accurate positioning on the substrate. This talk will discuss the design of the lens as well as particle tracing simulations to determine the proper lens voltage to focus the particle's trajectory. In the future, deposited graphene may be used to passivate H-terminated silicon. The method is expected to be generalizable to achieve deposition of 2D materials on surfaces in a clean UHV environment.

  4. Distributed systems and Ada

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Viewgraphs of two briefings designed to provide information to the Software I and V Study Group to help complete the I and V study task are given. The information is taken from the areas of Ada real-time processing support, Ada run-time environments, Ada program construction, object oriented design, and Ada/UNIX/POSIX interfaces. Also covered are the development, integration, and verification of Ada systems; fault tolerance and Ada; and Ada programming standards, techniques, and tools.

  5. Compact Fixed-exit UHV DCM for XAFS

    SciTech Connect

    Rickers, K.; Brueggmann, U.; Drube, W.; Herrmann, M.; Heuer, J.; Welter, E.; Schulte-Schrepping, H.; Schulz-Ritter, H.

    2007-01-19

    A double-crystal, UHV-compatible monochromator for XAFS applications at bending magnet beamlines has been designed. It uses two crystal sets, Si(111) and (311), on a common central rotation axis driven by an ex-vacuo goniometer. All mechanical and electrical components are mounted on a 400 mm UHV flange which is attached to a compact vacuum chamber. The first crystals are water cooled using connector- and bellowless tubing through the fluidic sealed feedthrough of the central rotation. The first crystal set is mounted off-axis and can be translated vertically to keep the fixed exit condition. The second crystal set uses small crystals of the same size as the first. In order to accept the reflected beam of the first crystal at small Bragg angles, it is tangentially translated along the beam. The angle can be varied from 5 deg. to 55.5 deg. resulting in a total energy range 2.4 - 43.4 keV for Si(111)/(311). Crystal sets are interchangeable by translating the vacuum chamber. Angle encoding is achieved by a Renishaw incremental optical encoder in vacuo.

  6. The Raid distributed database system

    NASA Technical Reports Server (NTRS)

    Bhargava, Bharat; Riedl, John

    1989-01-01

    Raid, a robust and adaptable distributed database system for transaction processing (TP), is described. Raid is a message-passing system, with server processes on each site to manage concurrent processing, consistent replicated copies during site failures, and atomic distributed commitment. A high-level layered communications package provides a clean location-independent interface between servers. The latest design of the package delivers messages via shared memory in a configuration with several servers linked into a single process. Raid provides the infrastructure to investigate various methods for supporting reliable distributed TP. Measurements on TP and server CPU time are presented, along with data from experiments on communications software, consistent replicated copy control during site failures, and concurrent distributed checkpointing. A software tool for evaluating the implementation of TP algorithms in an operating-system kernel is proposed.

  7. Dynamics of early stage nano-oxidation by in situ UHV-TEM

    NASA Astrophysics Data System (ADS)

    Yang, Judith

    2011-03-01

    Environmental stability is one of the most important properties for materials exposed to air. As dimensions of engineered systems approach nanoscale, fundamental understanding of reactions with oxygen at this length scale is critical for environmental stability as well as for processing oxide nanostructures, where surface reactions are commonly utilized. The nanoscale stages of oxidation from the nucleation of the metal oxide to the formation of the thermodynamically stable oxide represent a scientifically challenging and technologically important terra incognito. The kinetics of early stage oxidation of Cu, Cu-Au and Cu-Ni alloys were visualized using in situ ultra-high vacuum transmission electron microscopy (UHV-TEM), where the initial oxidation stages can be observed in real-time under well-controlled surface conditions. We examined the dynamic responses of thin films to variations in thermodynamic variables such as temperature, oxygen pressure, strain, and crystallographic orientation. The kinetics of the nucleation and growth of three-dimensional oxide islands demonstrate that oxygen surface diffusion is the primary mechanism for oxide growth during initial oxidation in dry oxygen, and thus bears a striking resemblance to heteroepitaxy. Compared with the behavior of Cu films, the oxidation of Cu-Au alloys revealed more complexity. For example, the oxidation of (100)-oriented Cu-Au alloys with low Au content at ~ 600 C results in the formation of Cu2O oxide islands with a dendritic morphology and a non-uniform lateral distribution of Au around the islands. For Cu-Ni oxidation, the addition of Ni causes the formation Cu2O and/or NiO where the oxide type(s) and the relative orientation with the film depend on the Ni concentration, oxygen partial pressure and temperature. Evolution of the shape and size of the oxide islands can be quantitatively analyzed and provide fundamental insights into the complex kinetics and energetics of oxidation. Models based on

  8. 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

  9. 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.

  10. Dynamics of copper oxidation investigated by in situ UHV-TEM

    NASA Astrophysics Data System (ADS)

    Zhou, Guangwen

    To bridge the gap between information provided by surface science methods (adsorption of up to ˜a few monolayers of oxygen) and that provided by bulk oxidation studies (typically, an oxide layer of a few microns or thicker), the initial stages of metal oxidation---from nucleation to coalescence---are being investigated by in situ ultra-high vacuum transmission electron microscopy (UHV-TEM). The aims of this thesis research are to gain basic insight into the complex kinetics and energetics of nano-oxide formation during the initial stages of oxidation, and fundamentally understand the distribution, stability, and morphological evolution of oxide islands since controlled oxidation is a processing tool for creating nanostructure patterns on surfaces. A systematic in situ study was carried out of the dynamic responses of Cu thin films to variations in thermodynamic variables such as temperature, oxygen pressure, strain, and crystallographic orientation. The main findings of the experiments include: (1) the universality of oxygen surface diffusion model, (2) formation of completely different oxide structure from oxide islands (disks, nanorods, dome, container pyramids) to disordered networks and almost uniform layer growth by altering the oxidation temperature and substrate orientation, (3) creation of nano-indentation arrays on metal surfaces by reducing the oxide arrays. The in situ UHV-TEM measurements of shape and size evolution of the oxides were used to gain fundamental insights into the complex kinetics and energetics of oxidation and reduction. Models based on the surfaces and strain during oxidation explained quantitatively the formation of some of the novel oxide nano-structures. A wealth of surface processes was discovered that reveal how each surface and thermodynamic condition needs to be considered for fundamentally understanding and controlling oxidation behavior.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Hydronic distribution system computer model

    SciTech Connect

    Andrews, J.W.; Strasser, J.J.

    1994-10-01

    A computer model of a hot-water boiler and its associated hydronic thermal distribution loop has been developed at Brookhaven National Laboratory (BNL). It is intended to be incorporated as a submodel in a comprehensive model of residential-scale thermal distribution systems developed at Lawrence Berkeley. This will give the combined model the capability of modeling forced-air and hydronic distribution systems in the same house using the same supporting software. This report describes the development of the BNL hydronics model, initial results and internal consistency checks, and its intended relationship to the LBL model. A method of interacting with the LBL model that does not require physical integration of the two codes is described. This will provide capability now, with reduced up-front cost, as long as the number of runs required is not large.

  17. 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.

  18. Distributed Supervisory Protection Interlock System

    SciTech Connect

    Walz, H.V.; Agostini, R.C.; Barker, L.; Cherkassky, R.; Constant, T.; Matheson, R.

    1989-03-01

    The Distributed Supervisory Protection Interlock System, DSPI, is under development at the Stanford Linear Accelerator Center for requirements in the areas of personnel protection, beam containment and equipment protection interlocks. The DSPI system, distributed over the application site, consists of segments with microprocessor-based controller and I/O modules, local area networks for communication, and a global supervisor computer. Segments are implemented with commercially available controller and I/O modules arranged in local interlock clusters, and associated software. Segments provide local interlock data acquisition, processing and control. Local area networks provide the communication backbone between segments and a global supervisor processor. The supervisor processor monitors the overall system, reports detail status and provides human interfaces. Details of an R and D test system, which will implement the requirements for personnel protection of 4 typical linear accelerator sectors, will be described. 4 refs., 2 figs.

  19. 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.

  20. The ATLAS distributed analysis system

    NASA Astrophysics Data System (ADS)

    Legger, F.; Atlas Collaboration

    2014-06-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  1. 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.

  2. 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.

  3. Oceanic Satellite Data Distribution System

    NASA Technical Reports Server (NTRS)

    Montgomery, D. R.

    1980-01-01

    The Satellite Data Distribution System (SDDS) serves to process satellite-derived ocean observations, generate ocean analysis and forecast products, and distribute the products to a limited set of commercial users. The SDDS functions in series with the U.S. Navy Fleet Numerical Oceanography Center (FNOC) to provide products on a near-real-time basis to commercial marine industries. Conventional meteorological and oceanographic observations provided to FNOC serve as the input set to the numerical analysis and forecast models. Large main-frame computers are used to analyze and forecast products on a routine, operational basis (at 6-hour and 12-hour synoptic times). The products, reformatted to meet commercial users needs, are transferred to a NASA-owned computer for storage and distribution. Access to the information is possible either by a commercial dial-up packet-switching network or by a direct computer-computer connection.

  4. CEBAF Distributed Data Acquisition System

    SciTech Connect

    Trent Allison; Thomas Powers

    2005-05-01

    There are thousands of signals distributed throughout Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) that are useful for troubleshooting and identifying instabilities. Many of these signals are only available locally or monitored by systems with small bandwidths that cannot identify fast transients. The Distributed Data Acquisition (Dist DAQ) system will sample and record these signals simultaneously at rates up to 40 Msps. Its primary function will be to provide waveform records from signals throughout CEBAF to the Experimental Physics and Industrial Control System (EPICS). The waveforms will be collected after the occurrence of an event trigger. These triggers will be derived from signals such as periodic timers or accelerator faults. The waveform data can then be processed to quickly identify beam transport issues, thus reducing down time and increasing CEBAF performance. The Dist DAQ system will be comprised of multiple standalone chassis distributed throughout CEBAF. They will be interconnected via a fiber optic network to facilitate the global triggering of events. All of the chassis will also be connected directly to the CEBAF Ethernet and run EPICS locally. This allows for more flexibility than the typical configuration of a single board computer and other custom printed circuit boards (PCB) installed in a card cage.

  5. Hazards Data Distribution System (HDDS)

    USGS Publications Warehouse

    Jones, Brenda; Lamb, Rynn

    2015-01-01

    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.

  6. 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.

  7. Prototype uhv compressed-gas-insulated transmission system

    NASA Astrophysics Data System (ADS)

    1982-02-01

    Development, manufacture, testing and installation of a 1200 kV compressed gas insulated transmission line (CGIT) and an SF6-air bushing are reported. Gas insulation studies of SF6 and mixtures with nitrogen, air or carbon dioxide were conducted. Pure SF6 at .45 MPa (50 psig) was selected for use in the prototype. Various materials and construction alternatives for the enclosure and conductor were investigated. Aluminum was chosen for both the enclosure and conductor. These provide the 5000 A 75% load factor thermal rating under standard burial and grounding conditions. Effects of alternate burial, grounding and bonding conditions are reported. For the solid support insulators low dielectric constant materials and epoxy were studied. An arc resistant epoxy formulation was developed and used for both conical and Tripost insulators. A high performance plug in contact for conductor joints was developed. Two versions of an SF6-air bushing were built and tested.

  8. Small Aircraft Data Distribution System

    NASA Technical Reports Server (NTRS)

    Chazanoff, Seth L.; Dinardo, Steven J.

    2012-01-01

    The CARVE Small Aircraft Data Distribution System acquires the aircraft location and attitude data that is required by the various programs running on a distributed network. This system distributes the data it acquires to the data acquisition programs for inclusion in their data files. It uses UDP (User Datagram Protocol) to broadcast data over a LAN (Local Area Network) to any programs that might have a use for the data. The program is easily adaptable to acquire additional data and log that data to disk. The current version also drives displays using precision pitch and roll information to aid the pilot in maintaining a level-level attitude for radar/radiometer mapping beyond the degree available by flying visually or using a standard gyro-driven attitude indicator. The software is designed to acquire an array of data to help the mission manager make real-time decisions as to the effectiveness of the flight. This data is displayed for the mission manager and broadcast to the other experiments on the aircraft for inclusion in their data files. The program also drives real-time precision pitch and roll displays for the pilot and copilot to aid them in maintaining the desired attitude, when required, during data acquisition on mapping lines.

  9. 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.

  10. Television Distribution System for Primary Schools.

    ERIC Educational Resources Information Center

    South Australia Education Dept., Adelaide.

    This report covers a 12-month study and actual trial of a video distribution system for a primary school. It consisted of a main aerial distribution into a distribution junction box which also took video cassette recorders. The whole system was designed to distribute both in RF and video frequencies. Some ways of using the system have also been…

  11. 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.

  12. 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

  13. 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.

  14. User Registration Systems for Distributed Systems

    NASA Astrophysics Data System (ADS)

    Murphy, K. J.; Cechini, M.; Pilone, D.; Mitchell, A.

    2010-12-01

    As NASA’s Earth Observing System Data and Information System (EOSDIS) systems have evolved over the years, most of the EOSDIS data are now available to users via anonymous on-line access. Although the changes have improved the dissemination efficiency of earth science data, the anonymous access has made it difficult to characterize users, capture metrics on the value of EOSDIS and provide customized services that benefit users. As the number of web-based applications continues to grow, data centers and application providers have implemented their own user registration systems and provided new tools and interfaces for their registered users. This has led to the creation of independent registration systems for accessing data and interacting with online tools and services. The user profile information maintained at each of these registration systems is not consistent and the registration enforcement varies by system as well. This problem is in no way unique to EOSDIS and represents a general challenge to the distributed computing community. In a study done in 2007(http://www2007.org/papers/paper620.pd), the average user has approximately 7 passwords for about 25 accounts and enters a password 8 times a day. These numbers have only increased in the last three years. To try and address this, a number of solutions have been offered including Single Sign-On solutions using a common backend like Microsoft Active Directory or an LDAP server, trust based identity providers like OpenID, and various forms of authorization delegation like OAuth or SAML/XACML. This talk discusses the differences between authentication and authorization, the state of the more popular user registration solutions available for distributed use, and some of the technical and policy drivers that need to be considered when incorporating a user registration system into your application.

  15. The Preparation and Properties of Niobium Superconducting Structures Prepared by Electron Beam Evaporation in Uhv

    NASA Astrophysics Data System (ADS)

    Goodchild, Martin S.

    Available from UMI in association with The British Library. This work has achieved the development of a fabrication method for the realisation of superconductor-insulator -superconductor (SIS) junctions based on niobium thin films with an artificial barrier layer. Such devices are likely to have advantages over lead alloy devices because of the enhanced mechanical and chemical stability. A principal objective was to attempt to exploit the offset mask technology developed by Dolan that has been successfully employed by Davies et.al. in the realisation of lead alloy SIS junction heterodyne mixers. In order to transfer this technology to niobium based devices it is essential that an evaporation method is used to allow shadow formation beneath the offset mask. As a result of the chemical reactivity and the low vapour pressure of niobium, a UHV system has been developed which incorporates an electrostatically focussed electron beam evaporation source. This is capable of providing deposition rates of close to 10A/sec. with a source to substrate distance of 120mm. During deposition the system pressure is below 5 times 10 ^{-9} mbar. These process parameters have been recorded, for a number of depositions, on a specially built data acquisition system controlled by a BBC microcomputer. Such recording allows detailed comparison of conditions which helps in the understanding of differences between the superconducting behaviour of various films. A further extremely important aspect of these real time measurements is that it helps to ensure optimum settings of the focus conditions of the electron beam source. The results of the depositions are extremely encouraging with critical temperatures of between 9.1 and 9.3K being achieved. These results compare well with expected values for bulk niobium. An all-metal offset mask technology has been developed to replace the photo-resist technique pioneered by Dolan. This new method is needed because the photo-resist is not compatible

  16. An ultrahigh vacuum (UHV) apparatus to study the interaction between adsorbates and photons

    NASA Astrophysics Data System (ADS)

    Jenniskens, Hans G.; Bot, Arjen; Dorlandt, Paul W. F.; van Essenberg, Wouter; de Haas, Evert; Kleyn, Aart W.

    1997-11-01

    An UHV apparatus has been designed and constructed for studying the interaction between adsorbates and photons. Since a variety of light sources and experimental geometries are used in these studies, the system was designed to be as flexible as possible. The system is put on a single frame so that it can be transported from one photon source to another. A compact, exchangeable, high-pressure cell is designed to provide easy access for photons to the crystal. To allow the study of small poly-atomics the following combination of detection techniques are installed: thermal desorption spectroscopy (TDS), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and reflection - adsorption infrared spectroscopy (RAIRS). Furthermore, a sample exchange system in combination with liquid nitrogen sample cooling is incorporated. The exchange system allows three samples to be stored in the main chamber. The sample exchange capability does not restrict the cooling capabilities - 85 K within an hour after turning on the liquid nitrogen flow and 85 K within minutes after flashing to 800 K.

  17. Monitoring the DIRAC distributed system

    NASA Astrophysics Data System (ADS)

    Santinelli, R.; Seco, M.; Nandakumar, R.; LHCb DIRAC Team

    2010-04-01

    DIRAC, the LHCb community Grid solution, is intended to reliably run large data mining activities. The DIRAC system consists of various services (which wait to be contacted to perform actions) and agents (which carry out periodic activities) to direct jobs as required. An important part of ensuring the reliability of the infrastructure is the monitoring and logging of these DIRAC distributed systems. The monitoring is done collecting information from two sources - one is from pinging the services or by keeping track of the regular heartbeats of the agents, and the other from the analysis of the error messages generated both by agents and services and collected by a logging system. This allows us to ensure that the components are running properly and to collect useful information regarding their operations. The process status monitoring is displayed using the SLS sensor mechanism that also automatically allows to plot various quantities and keep a history of the system. A dedicated GridMap interface (ServiceMap) allows production shifters and experts to have an immediate, high-impact view of all LHCb critical services status while offering the possibility to refer to details of the SLS and SAM sensors. Error types and statistics provided by the logging service can be accessed via dedicated web interfaces on the DIRAC portal or programmatically via the python based API and CLI.

  18. 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.

  19. 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.

  20. 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.

  1. A quadrupole ion trap mass spectrometer for in-situ UHV analyses on Earth and other planetary environments

    NASA Astrophysics Data System (ADS)

    Cox, S. E.; Madzunkov, S. M.; Simcic, J.; Farley, K. A.

    2014-12-01

    The JPL quadrupole ion trap mass spectrometer presents an exceptional opportunity for combining cutting edge terrestrial geochemical research with the next generation of extraterrestrial science. The QIT is a small mass spectrometer that filters particles of different mass by electron ionization and subsequent separation with a quadrupole RF field. The latest version is capable of achieving very high resolution (R > 1000) without an increase in power consumption through the addition of a dipole RF to augment the primary quadrupole field. Crucially, we demonstrate the ability to achieve this resolution with high sensitivity (> 1014 cps/Torr), and at UHV without the addition of a cooling gas. In this mode, the high sensitivity and extremely low background allow the measurement of a large number of species in very small samples. Most laboratory instruments are too heavy, large, and energy-intensive to fly on spacecraft in their optimal forms. As a result, instruments for spaceflight have traditionally been heavily-modified versions of terrestrial instruments, designed to be lighter, smaller, and more efficient than their terrestrial counterparts, at the expense of analytical capabilities. The JPL QIT, in contrast, weighs less than 1 kg, is only a few cm in size, and consumes less than 30W. Only the accompanying UHV system and supporting electronics must be extensively redesigned for spaceflight, and NASA already possesses pumps capable of fulfilling this need. The opportunity for parallel development for terrestrial and extraterrestrial labs and the capability of direct comparison between planetary science and terrestrial geochemistry will benefit both fields.

  2. 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.

  3. Protection of Active Distribution Systems with DGs

    NASA Astrophysics Data System (ADS)

    Akila, Abdelrahman Ahmed; Helal, Ahmed; Eldesouki, Hussein

    2015-10-01

    Distribution systems are traditionally designed as radial passive systems fed from a single source. Protection coordination of such systems has been easily established assuming the system radiality. Insertion of distributed generators (DGs) into distribution systems makes the distribution system to be more active which causes redistribution of fault currents magnitudes and directions. This causes negative impacts on the original protection system coordination, since the distribution system losses its radiality and passiveness. Recently protection coordination in the presence of distributed generation has been paid a great attention. Researchers proposed various solutions to solve the protection coordination problem caused by adding DG into the distribution network. In this paper, the proposed solutions for the protection coordination problem considering the DG insertion will be illustrated, classified, and criticized.

  4. TIG welding of aluminum alloys for the APS storage ring - a UHV application

    SciTech Connect

    Goeppner, G.A.

    1996-05-29

    The Advanced Photon Source (APS) incorporates a 7-GeV positron storage ring 1104 meters in circumference. The storage ring vacuum system is designed to maintain a pressure of 1 nTorr or less with a circulating current of 300 mA to enable beam lifetimes of greater than 10 hours. The vacuum chamber is an aluminum extrusion of 6063T5 alloy. There are 235 separate aluminum vacuum chambers in the storage ring connected by stainless steel bellows assemblies. Aluminum was chosen for the vacuum chamber because it can be economically extruded and machined, has good thermal conductivity, low thermal emissivity, a low outgassing rate, low residual radioactivity, and is non-magnetic. The 6063 aluminum-silicon-magnesium alloy provides high strength combined with good machining and weldability characteristics. The extrusion process provides the interior surface finish needed for the ultrahigh vacuum (UHV) environments There are six different vacuum chambers with the same extrusion cross section. The average vacuum chamber length is 171.6 inches. The extruded vacuum chambers are welded to flange assemblies made up of machined 2219 aluminum alloy pieces and 2219 aluminum vacuum flanges from a commercial source.

  5. A low and hyperthemal energy UHV ion beamline for surface scattering spectroscopies

    NASA Astrophysics Data System (ADS)

    Ray, M. P.; Moody, S. A.; Sosolik, C. E.

    2006-03-01

    We are using a differentially pumped beamline to provide well- collimated, monoenergetic beams of noble gas and alkali-metal ions that range in energy from <10eV to 10keV. These ion beams are scattered from a surface (e.g. Cu(001)) to study charge transfer effects, energy loss, and the excitation of surface phonons and excitons. The ion beam is focused into a UHV scattering chamber that possesses capabilities for studying and characterizing samples using LEED, Auger spectroscopy, and a Kelvin probe for work function measurements. Recent additions to this setup include replacing diffusion pumps with turbo pumps as well as the addition of a fast entry load-lock sample exchange system. Our current research is focused on developing a source to produce an ion beam of C60 as well as studying charge transfer and energy loss effects at the low and hyperthermal energy range. Also, we are investigating chemicurrents associated with Schottky diodes in this energy regime.

  6. Low jitter RF distribution system

    SciTech Connect

    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.

  7. 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.

  8. 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.

  9. 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.

  10. A Survey on Distributed File System Technology

    NASA Astrophysics Data System (ADS)

    Blomer, J.

    2015-05-01

    Distributed file systems provide a fundamental abstraction to location-transparent, permanent storage. They allow distributed processes to co-operate on hierarchically organized data beyond the life-time of each individual process. The great power of the file system interface lies in the fact that applications do not need to be modified in order to use distributed storage. On the other hand, the general and simple file system interface makes it notoriously difficult for a distributed file system to perform well under a variety of different workloads. This has lead to today's landscape with a number of popular distributed file systems, each tailored to a specific use case. Early distributed file systems merely execute file system calls on a remote server, which limits scalability and resilience to failures. Such limitations have been greatly reduced by modern techniques such as distributed hash tables, content-addressable storage, distributed consensus algorithms, or erasure codes. In the light of upcoming scientific data volumes at the exabyte scale, two trends are emerging. First, the previously monolithic design of distributed file systems is decomposed into services that independently provide a hierarchical namespace, data access, and distributed coordination. Secondly, the segregation of storage and computing resources yields to a storage architecture in which every compute node also participates in providing persistent storage.

  11. 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.

  12. Accuracy analysis of distributed simulation systems

    NASA Astrophysics Data System (ADS)

    Lin, Qi; Guo, Jing

    2010-08-01

    Existed simulation works always emphasize on procedural verification, which put too much focus on the simulation models instead of simulation itself. As a result, researches on improving simulation accuracy are always limited in individual aspects. As accuracy is the key in simulation credibility assessment and fidelity study, it is important to give an all-round discussion of the accuracy of distributed simulation systems themselves. First, the major elements of distributed simulation systems are summarized, which can be used as the specific basis of definition, classification and description of accuracy of distributed simulation systems. In Part 2, the framework of accuracy of distributed simulation systems is presented in a comprehensive way, which makes it more sensible to analyze and assess the uncertainty of distributed simulation systems. The concept of accuracy of distributed simulation systems is divided into 4 other factors and analyzed respectively further more in Part 3. In Part 4, based on the formalized description of framework of accuracy analysis in distributed simulation systems, the practical approach are put forward, which can be applied to study unexpected or inaccurate simulation results. Following this, a real distributed simulation system based on HLA is taken as an example to verify the usefulness of the approach proposed. The results show that the method works well and is applicable in accuracy analysis of distributed simulation systems.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Resource Management for Distributed Parallel Systems

    NASA Technical Reports Server (NTRS)

    Neuman, B. Clifford; Rao, Santosh

    1993-01-01

    Multiprocessor systems should exist in the the larger context of distributed systems, allowing multiprocessor resources to be shared by those that need them. Unfortunately, typical multiprocessor resource management techniques do not scale to large networks. The Prospero Resource Manager (PRM) is a scalable resource allocation system that supports the allocation of processing resources in large networks and multiprocessor systems. To manage resources in such distributed parallel systems, PRM employs three types of managers: system managers, job managers, and node managers. There exist multiple independent instances of each type of manager, reducing bottlenecks. The complexity of each manager is further reduced because each is designed to utilize information at an appropriate level of abstraction.

  7. 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.

  8. 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

  9. 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.

  10. Parallel and Distributed System Simulation

    NASA Technical Reports Server (NTRS)

    Dongarra, Jack

    1998-01-01

    This exploratory study initiated our research into the software infrastructure necessary to support the modeling and simulation techniques that are most appropriate for the Information Power Grid. Such computational power grids will use high-performance networking to connect hardware, software, instruments, databases, and people into a seamless web that supports a new generation of computation-rich problem solving environments for scientists and engineers. In this context we looked at evaluating the NetSolve software environment for network computing that leverages the potential of such systems while addressing their complexities. NetSolve's main purpose is to enable the creation of complex applications that harness the immense power of the grid, yet are simple to use and easy to deploy. NetSolve uses a modular, client-agent-server architecture to create a system that is very easy to use. Moreover, it is designed to be highly composable in that it readily permits new resources to be added by anyone willing to do so. In these respects NetSolve is to the Grid what the World Wide Web is to the Internet. But like the Web, the design that makes these wonderful features possible can also impose significant limitations on the performance and robustness of a NetSolve system. This project explored the design innovations that push the performance and robustness of the NetSolve paradigm as far as possible without sacrificing the Web-like ease of use and composability that make it so powerful.

  11. 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.

  12. Distributed Administrative Management Information System (DAMIS).

    ERIC Educational Resources Information Center

    Juckiewicz, Robert; Kroculick, Joseph

    Columbia University's major program to distribute its central administrative data processing to its various schools and departments is described. The Distributed Administrative Management Information System (DAMIS) will link every department and school within the university via micrcomputers, terminals, and/or minicomputers to the central…

  13. 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...

  14. 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,…

  15. Man-systems distributed system for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Lewis, J. L.

    1990-01-01

    Viewgraphs on man-systems distributed system for Space Station Freedom are presented. Topics addressed include: description of man-systems (definition, requirements, scope, subsystems, and topologies); implementation (approach, tools); man-systems interfaces (system to element and system to system); prime/supporting development relationship; selected accomplishments; and technical challenges.

  16. 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.

  17. Computer Systems for Distributed and Distance Learning.

    ERIC Educational Resources Information Center

    Anderson, M.; Jackson, David

    2000-01-01

    Discussion of network-based learning focuses on a survey of computer systems for distributed and distance learning. Both Web-based systems and non-Web-based systems are reviewed in order to highlight some of the major trends of past projects and to suggest ways in which progress may be made in the future. (Contains 92 references.) (Author/LRW)

  18. 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.

  19. In situ sputter cleaning of thin film metal substrates for UHV-TEM corrosion studies.

    NASA Technical Reports Server (NTRS)

    Heinemann, K.; Poppa, H.

    1973-01-01

    A prerequisite for conducting valid corrosion experiments by in situ electron microscopy techniques is not only the achievement of UHV background pressure conditions at the site of the specimen but also the ability to clean the surface of the thin metal substrate specimen before initiation of the corrosive interaction. A miniaturized simple ion gun has been constructed for this purpose. The gun is small enough to be incorporated into an UHV electron microscope specimen chamber with hot stage in such a way as to permit bombardment of the substrate specimen while observing it by transmission electron microscopy TEM. It is shown that the ion beam generated is confined well enough to cause a sputtering removal of substrate material at a rate of approximately 5-10 A/min and to prevent the sputter deposition of contaminating material from the specimen holder.

  20. Model studies in catalysis with uhv-deposited metal particles and clusters

    NASA Technical Reports Server (NTRS)

    Poppa, H.

    1984-01-01

    Small supported metal particles have become a popular area of intense research interest, and important contributions to the considered problems are being made from the fields of uhv technology, thin film physics surface science, and surface and thin film instrumentation. Attention is given to insulating supports, particulate metal deposits and their properties, metal/support interactions and gas exposures, and integrated experimental approaches. It is concluded that major contributions to the field of model catalysis should be forthcoming in the near future from uhv-based methods of research. Catalysis and catalysis-related problem areas expected to benefit from advanced model studies include catalyst preparation processing, sintering mechanisms for metals and alloys, separation of initial and final state effects for supported clusters, and the influence of particle and/or support morphologies.

  1. 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.

  2. 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

  3. Examination and characterization of distribution system biofilms.

    PubMed

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

    1987-12-01

    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. PMID:3435140

  4. 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.

  5. UHV studies of the interaction of CO with small supported metal particles, Ni/mica

    NASA Technical Reports Server (NTRS)

    Doering, D. L.; Poppa, H.; Dickinson, J. T.

    1982-01-01

    The interaction of carbon monoxide with small nickel (Ni) particles supported on UHV-cleaved mica was studied using flash thermal desorption, Auger electron spectroscopy, and transmission electron microscopy. Molecular desorption was accompanied by decomposition of CO at a rate strongly dependent on particle size. Recombination of surface-precipitated carbon with adsorbed oxygen was observed, and gas-induced morphological particle changes because of exposure to CO and O2 are analyzed in some detail.

  6. 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.

  7. Heterogeneous distributed query processing: The DAVID system

    NASA Technical Reports Server (NTRS)

    Jacobs, Barry E.

    1985-01-01

    The objective of the Distributed Access View Integrated Database (DAVID) project is the development of an easy to use computer system with which NASA scientists, engineers and administrators can uniformly access distributed heterogeneous databases. Basically, DAVID will be a database management system that sits alongside already existing database and file management systems. Its function is to enable users to access the data in other languages and file systems without having to learn the data manipulation languages. Given here is an outline of a talk on the DAVID project and several charts.

  8. 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.

  9. 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.

  10. Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

    NASA Astrophysics Data System (ADS)

    Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

    2014-05-01

    An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

  11. Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts.

    PubMed

    Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

    2014-05-01

    An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown. PMID:24880412

  12. Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

    SciTech Connect

    Mayr, Lukas; Klötzer, Bernhard; Penner, Simon; Rameshan, Raffael; Rameshan, Christoph

    2014-05-15

    An ultra-high vacuum (UHV) setup for “real” and “inverse” model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, “magic angle”) and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

  13. 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.

  14. Cooperative Autonomic Management in Dynamic Distributed Systems

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Zhao, Ming; Fortes, José A. B.

    The centralized management of large distributed systems is often impractical, particularly when the both the topology and status of the system change dynamically. This paper proposes an approach to application-centric self-management in large distributed systems consisting of a collection of autonomic components that join and leave the system dynamically. Cooperative autonomic components self-organize into a dynamically created overlay network. Through local information sharing with neighbors, each component gains access to global information as needed for optimizing performance of applications. The approach has been validated and evaluated by developing a decentralized autonomic system consisting of multiple autonomic application managers previously developed for the In-VIGO grid-computing system. Using analytical results from complex random network and measurements done in a prototype system, we demonstrate the robustness, self-organization and adaptability of our approach, both theoretically and experimentally.

  15. 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.

  16. Real-time distributed multimedia systems

    SciTech Connect

    Rahurkar, S.S.; Bourbakis, N.G.

    1996-12-31

    This paper presents a survey on distributed multimedia systems and discusses real-time issues. In particular, different subsystems are reviewed that impact on multimedia networking, the networking for multimedia, the networked multimedia systems, and the leading edge research and developments efforts and issues in networking.

  17. 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.

  18. An Evaluation of a Distributed Learning System.

    ERIC Educational Resources Information Center

    Lawther, Peter M; Walker, Derek H. T.

    2001-01-01

    A survey of 306 undergraduate and graduate students, focus groups, and lecturers' reports evaluated a Web-enabled distributed learning system. The system was popular with students, flexible, self-paced, and empowering; technical support difficulties generated frustration. There was less interaction than desired and a lack of instant feedback and…

  19. 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…

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. A expert system for locating distribution system faults

    SciTech Connect

    Hsu, Y.Y.; Lu, F.C.; Chien, Y. . Dept. of Electrical Engineering); Liu, J.P.; Lin, J.T. ); Yu, H.S.; Kuo, R.T )

    1991-01-01

    A rule-based expert system is designed to locate the faults in a distribution system. Distribution system component data and network topology are stored in the database. A set of heuristic rules are compiled from the dispatchers' experience and are imbedded in the rule base. To locate distribution system fault, an inference engine is developed to perform deductive reasonings on the rules in the knowledge base. The inference engine comprises three major parts: the dynamic searching method, the backtracking approach, and the set intersection operation. The expert system is implemented on a personal computer using the artificial intelligence language PROLOG. To demonstrate the effectiveness of the proposed approach, the expert system has been applied to locate faults in a real underground distribution system.

  6. 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.

  7. 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.

  8. Distributed Object Oriented Geographic Information System

    Energy Science and Technology Software Center (ESTSC)

    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

  9. High temperature hot water distribution system study

    SciTech Connect

    1996-12-01

    The existing High Temperature Hot Water (HTHW) Distribution System has been plagued with design and construction deficiencies since startup of the HTHW system, in October 1988. In October 1989, after one year of service, these deficiencies were outlined in a technical evaluation. The deficiencies included flooded manholes, sump pumps not hooked up, leaking valves, contaminated HTHW water, and no cathodic protection system. This feasibility study of the High Temperature Hot Water (HTHW) Distribution System was performed under Contract No. DACA0l-94-D-0033, Delivery Order 0013, Modification 1, issued to EMC Engineers, Inc. (EMC), by the Norfolk District Corps of Engineers, on 25 April 1996. The purpose of this study was to determine the existing conditions of the High Temperature Hot Water Distribution System, manholes, and areas of containment system degradation. The study focused on two areas of concern, as follows: * Determine existing conditions and areas of containment system degradation (leaks) in the underground carrier pipes and protective conduit. * Document the condition of underground steel and concrete manholes. To document the leaks, a site survey was performed, using state-of-the-art infrared leak detection equipment and tracer gas leak detection equipment. To document the condition of the manholes, color photographs were taken of the insides of 125 manholes, and notes were made on the condition of these manholes.

  10. POLRADS: polarization radiance distribution measurement system.

    PubMed

    Voss, Kenneth J; Souaidia, Nordine

    2010-09-13

    While the upwelling radiance distribution in the ocean can be highly polarized, there are few measurements of this parameter in the open ocean. To obtain the polarized in-water upwelling spectral radiance distribution data we have developed the POLRADS instrument. This instrument is based on the NuRADS radiance distribution camera systems in which linear polarizer's have been installed. By combining simultaneous images from three NuRADS instruments, three Stokes parameters (I, Q, U) for the water leaving radiance can be obtained for all upwelling angles simultaneously. This system measures the Stokes parameters Q/I and U/I with a 0.05-0.06 uncertainty and I with a 7-10% uncertainty. PMID:20940862

  11. 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.

  12. METALS DISTRIBUTIONS IN ACTIVATED SLUDGE SYSTEMS

    EPA Science Inventory

    This project developed models to predict the distribution of metals in activated sludge system process streams. The data used to develop the models were obtained through extended pilot studies from a previous project. The objectives of the study were to evaluate the effects of wa...

  13. STANDARDIZED COST FOR WATER SUPPLY DISTRIBUTION SYSTEMS

    EPA Science Inventory

    There are a significant number of water supply distribution systems in the United States that are deteriorating, resulting in a potential threat to the future quality of drinking water. orrective measures will directly influence the cost of providing water. t would be useful to h...

  14. 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…

  15. 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...

  16. Workflow management in large distributed systems

    NASA Astrophysics Data System (ADS)

    Legrand, I.; Newman, H.; Voicu, R.; Dobre, C.; Grigoras, C.

    2011-12-01

    The MonALISA (Monitoring Agents using a Large Integrated Services Architecture) framework provides a distributed service system capable of controlling and optimizing large-scale, data-intensive applications. An essential part of managing large-scale, distributed data-processing facilities is a monitoring system for computing facilities, storage, networks, and the very large number of applications running on these systems in near realtime. All this monitoring information gathered for all the subsystems is essential for developing the required higher-level services—the components that provide decision support and some degree of automated decisions—and for maintaining and optimizing workflow in large-scale distributed systems. These management and global optimization functions are performed by higher-level agent-based services. We present several applications of MonALISA's higher-level services including optimized dynamic routing, control, data-transfer scheduling, distributed job scheduling, dynamic allocation of storage resource to running jobs and automated management of remote services among a large set of grid facilities.

  17. Photochemical Production of Oligothiophene and Polythiophene Micropatterns from 2,5-diiodothiophene on Au in UHV

    SciTech Connect

    Liu,G.; Natarajan, S.; Kim, S.

    2005-01-01

    Fabrication of oligothiophene and polythiophene micropatterns is demonstrated by photochemical reactions of 2, 5-diiodothiophene adsorbed on an Au coated Si wafer under UHV conditions. For patterning, a TEM grid is utilized as a model stencil mask. Fluorescence microscopic analysis shows that polymer microstructures with good pattern fidelity are attained over a large area. RAIRS and NEXAFS analyses indicate that the electronic and molecular structures of the produced polymer are similar to those of chemically synthesized polythiophene. The structural defects of the photochemically produced polymer are negligible. The present procedure provides a very efficient strategy for growth and patterning of conjugated polymer microstructures with high quality in one step.

  18. A Sealed, UHV Compatible, Soft X-ray Detector Utilizing Gas Electron Multipliers

    SciTech Connect

    Schaknowski, N.A.; Smith, G.

    2009-10-25

    An advanced soft X-ray detector has been designed and fabricated for use in synchrotron experiments that utilize X-ray absorption spectroscopy in the study a wide range of materials properties. Fluorescence X-rays, in particular C{sub K} at 277eV, are converted in a low pressure gas medium, and charge multiplication occurs in two gas electron multipliers, fabricated in-house from glass reinforced laminate, to enable single photon counting. The detector satisfies a number of demanding characteristics often required in synchrotron environments, such as UHV compatibility compactness, long-term stability, and energy resolving capability.

  19. UHV studies of the interaction of CO with small supported metal particles, Pd/mica

    NASA Technical Reports Server (NTRS)

    Doering, D. L.; Poppa, H.; Dickinson, J. T.

    1982-01-01

    The interaction of carbon monoxide with small palladium particles supported on UHV-cleaved and heat-treated single-crystal mica was studied. The Pd particles were characterized and tested using the techniques of flash thermal desorption, Auger electron spectroscopy, core electron energy loss spectroscopy, and transmission electron microscopy. Evidence is presented for CO decomposition on Pd particles during CO adsorption-desorption experiments. The rate of CO decomposition increased rapidly with diminishing particle size. Residual carbon from CO decomposition blocked CO adsorption and had a strong poisoning effect on the CO oxidation reaction.

  20. Non Evaporable Getter (NEG) Pumps: a Route to UHV-XHV

    SciTech Connect

    Manini, Paolo

    2009-08-04

    Non Evaporable Getter (NEG) technology has been developed in the 1970's and since then adopted by industry, R and D labs, research centres and in large physics projects like accelerators, synchrotrons and fusion reactors. NEG pumps are very compact and vibration-free devices able to deliver very high pumping with minimal power requirement and electromagnetic interference. In the present paper, main features and performances of getter pumps are reviewed and discussed with a special focus to photocathode gun application, where UHV or XHV conditions are mandatory to ensure adequate gun life. NEG coating and future challenges for NEG technology are also discussed.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Distribution of Quantum Coherence in Multipartite Systems

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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 X X Z 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.

  6. PILOT: An intelligent distributed operations support system

    NASA Technical Reports Server (NTRS)

    Rasmussen, Arthur N.

    1993-01-01

    The Real-Time Data System (RTDS) project is exploring the application of advanced technologies to the real-time flight operations environment of the Mission Control Centers at NASA's Johnson Space Center. The system, based on a network of engineering workstations, provides services such as delivery of real time telemetry data to flight control applications. To automate the operation of this complex distributed environment, a facility called PILOT (Process Integrity Level and Operation Tracker) is being developed. PILOT comprises a set of distributed agents cooperating with a rule-based expert system; together they monitor process operation and data flows throughout the RTDS network. The goal of PILOT is to provide unattended management and automated operation under user control.

  7. 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.

  8. High-performance computing and distributed systems

    SciTech Connect

    Loken, S.C.; Greiman, W.; Jacobson, V.L.; Johnston, W.E.; Robertson, D.W.; Tierney, B.L.

    1992-09-01

    We present a scenario for a fully distributed computing environment in which computing, storage, and I/O elements are configured on demand into ``virtual systems`` that are optimal for the solution of a particular problem. We also describe present two pilot projects that illustrate some of the elements and issues of this scenario. The goal of this work is to make the most powerful computing systems those that are logically assembled from network based components, and to make those systems available independent of the geographic location of the constituent elements.

  9. High-performance computing and distributed systems

    SciTech Connect

    Loken, S.C.; Greiman, W.; Jacobson, V.L.; Johnston, W.E.; Robertson, D.W.; Tierney, B.L.

    1992-09-01

    We present a scenario for a fully distributed computing environment in which computing, storage, and I/O elements are configured on demand into virtual systems'' that are optimal for the solution of a particular problem. We also describe present two pilot projects that illustrate some of the elements and issues of this scenario. The goal of this work is to make the most powerful computing systems those that are logically assembled from network based components, and to make those systems available independent of the geographic location of the constituent elements.

  10. Distributed parallel messaging for multiprocessor systems

    DOEpatents

    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.

  11. 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.

  12. 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.

  13. 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.

  14. Modeling distributed systems with logic programming languages

    SciTech Connect

    Lenders, P.M.

    1985-01-01

    This thesis proposes new concepts for an ideal integrated specification and simulation workstation. The transition model approach to distributed systems specification is improved by the introduction of communicating finite state automata (CFSA), and a Prolog implementation of CFSA. Liveness and safety properties are proved with Prolog. Bidirectional input-output (bi-io), a new input-output mechanism is introduced, which eases distributed systems programming. It generalizes regular input-output mechanisms, replacing two concepts with one single concept. Moreover, it is concise and powerful, and for some applications suppresses deadlock problems. Bi-io is proposed as an extension of Communicating Sequential Processes (CSP). An axiomatic semantics of the extended CSP language is given, which follows the weakest precondition approach. The similarities between CFSA and CSP (with its weakest precondition semantics) suggest that the two descriptive methods should be used together with the ideal specification and simulation workstation.

  15. 47 CFR 73.6023 - Distributed transmission systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Distributed transmission systems. 73.6023... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission... distributed transmission system....

  16. 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....

  17. 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....

  18. 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....

  19. 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....

  20. Development of UHV compatible machined diamond profile gaskets for INDUS-2

    NASA Astrophysics Data System (ADS)

    Yadav, D. P.; Shiroman, R.; Shukla, S. K.; Kotaiah, S.

    2008-05-01

    Ultra High Vacuum (UHV) compatible demountable joints are needed in Indus-2 (2.5 GeV, 300mA) electron storage ring for connecting Al-alloy vacuum chambers (homogeneous joints) as well as Al-alloy vacuum chambers to well proven stainless steel components like beam diagnostic components and RF-shielded bellow assemblies (heterogeneous joints). Bakeable & reliable diamond profile Al-alloy gaskets have been developed for Helium leak rate less than 2×10-10 Std. CC/sec, which eliminated the need of any Al to SS transition pieces onto the Aluminium vacuum chambers. Salient features of these gaskets are: high reliability, low cost, reduced flange thickness, self alignment, ease in installation, less torque requirement, formability to non-circular shape & ultra cleanliness. These diamond profile gaskets were machined from extruded Al-alloy 6061-T5 pipes using specially developed high-speed steel formed cutting tools. Thermal cyclic tests were carried to check the reliability of these gaskets. No leaks were found even after several bakeouts at 150°C. Non-circular metallic gaskets like the one used in UHV gate valve bonnet seal can also be manufactured using specially developed formed toolings. This paper describes basic design philosophy, manufacturing process and testing details of these gaskets.

  1. Explosion bonding of dissimilar materials for fabricating APS front end components: Analysis of metallurgical and mechanical properties and UHV applications

    SciTech Connect

    Li, Yuheng; Shu, Deming; Kuzay, T.M.

    1994-06-15

    The front end beamline section contains photon shutters and fixed masks. These components are made of OFHC copper and GlidCOP AL-15. Stainless steels (304 or 316) are also used for connecting photon shutters and fixed masks to other components that operate in the ultrahigh vacuum system. All these dissimilar materials need to be joined together. However, bonding these dissimilar materials is very difficult because of their different mechanical and thermal properties and incompatible metallurgical properties. Explosion bonding is a bonding method in which the controlled energy of a detonating explosive is used to create a metallurgical bond between two or more similar or dissimilar materials. No intermediate filler metal, for example, a brazing compound or soldering alloy, is needed to promote bonding, and no external heat need be applied. A study of the metallurgical and mechanical properties and YGV applications of GlidCop AL-15, OFHC copper, and 304 stainless steel explosion-bonded joints has been done. This report contains five parts: an ultrasonic examination of explosion-bonded joints and a standard setup; mechanical-property and thermal-cycle tests of GlidCop AL-15/304 stainless steel explosion-bonded joints; leak tests of a GlidCop AL-15/304 stainless steel explosion-bonded interfaces for UHV application; metallurgical examination of explosion-bonded interfaces and failure analysis, and discussion and conclusion.

  2. 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.

  3. 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.

  4. NLOS UV communication for distributed sensor systems

    NASA Astrophysics Data System (ADS)

    Shaw, Gary A.; Nischan, Melissa L.; Iyengar, Mrinal A.; Kaushik, Sumanth; Griffin, Michael K.

    2000-11-01

    Atmospheric scattering of ultraviolet light is examined as a mechanism for short-range, non-line-of-sight (NLOS) communication between nodes in energy-constrained distributed sensor networks. The physics of scattering is discussed and modeled, and progress in the development of solid state sources and detectors is briefly summarized. The performance of a representative NLOS UV communication system is analyzed by means of a simulation model and compared to conventional RF systems in terms of covertness and transceiver power. A test bed for evaluating NLOS UV communication hardware and modulation schemes is described.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. FRIB Cryogenic Distribution System and Status

    SciTech Connect

    Ganni, Venkatarao; Dixon, Kelly D.; Laverdure, Nathaniel A.; Yang, Shuo; Nellis, Timothy; Jones, S.; Casagrande, Fabio

    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. Distribution system planning using knowledge based expert system

    SciTech Connect

    Ranjan, R.; Das, D.; Kothari, D.P.

    1995-12-31

    In this paper an attempt is made to develop a new algorithm for distribution system planning. Generalized algorithm is developed for obtaining the optimal feeder path and optimal location of substation based on minimum loss criteria. The proposed method can handle all the heuristic rules. Also presented are a new load flow algorithm for solving radial distribution feeders and a branch conductor optimization algorithm. The load flow and branch conductor optimization techniques are used as subroutine in the generalized distribution planning algorithm. Several problems have been successfully tested using the proposed algorithm and results are highly satisfactory.

  11. 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

  12. Velocity distribution in active particles systems

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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.

  13. 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.

  14. Expert system prototype of food aid distribution.

    PubMed

    Singh, Neeta

    2007-01-01

    The aim of this study was to improve efficiency of the food aid distribution process of international food relief organizations. An overall objective of this study was to develop a prototype expert system for monitoring and evaluating food aid by international disaster relief organizations. The research identifies data related to monitoring and evaluation processes of various international food-aid organizations. It then applies an artificial intelligence-based expert system to develop a prototype for those processes. Existing data related to monitoring and evaluation program cycles were obtained. An expert system shell called CLIPS(c) (National Aeronautics Space Administration) was used to develop a prototype system named Food Aid Monitor, a rule-based expert system, which uses facts and heuristic rules to provide an adaptive feedback regarding monitoring and evaluating processes at various stages of food aid operation. The Food Aid Monitor was evaluated and validated by three expert panels checking the prototype system for completeness, relevancy, consistency, correctness, precision, and use-ability. Finally, the panels indicated a belief that the system could have an overall positive impact on the stages of monitoring and evaluating food aid processes of the food relief organizations. PMID:17392088

  15. 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.

  16. Power quality monitoring of a distribution system

    SciTech Connect

    Barker, P.P.; Burke, J.T.; Mancao, R.T.; Short, T.A.; Warren, C.A. ); Burns, C.W.; Siewierski, J.J. )

    1994-04-01

    The Niagara Mohawk Power Corporation (NMPC) Research and Development Department sponsored a major power quality study of two distribution feeders in the Buffalo, New York region. All levels of these systems, from the substation bus to the customer service entrance, were instrumented with monitoring equipment. A variety of measurements, encompassing both transient and steady state system behavior, were performed. The use of multiple monitoring locations allowed NMPC to assess the origins and scope of various disturbances. The study generated a database which can serve as a guide for assessing relative power quality on the NMPC system. The study also formulated suggestions on areas which the industry (both the power industry and consumer products industry) might address in the future on the effect of standard utility operation towards consumer appliances.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  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. The physics of distributed information systems

    NASA Astrophysics Data System (ADS)

    Aurell, Erik

    2013-12-01

    This paper aims to introduce Distributed Systems as a field where the ideas and methods of physics can potentially be applied, and to provide entry points to a wide literature. The contributions of Leslie Lamport, inspired by Relativity Theory, and of Edsger Dijkstra, which has the flavor of a growth process, are discussed at some length. The intent of the author is primarily to stimulate interest in the statistical physics community, and the discussions are therefore framed in a non-technical language; the author apologizes in advance to readers from the computer science side for the unavoidable impreciseness and ambiguities.

  4. 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.

  5. Data management system for distributed virtual screening.

    PubMed

    Zhou, Ting; Caflisch, Amedeo

    2009-01-01

    High throughput docking (HTD) using high performance computing platforms is a multidisciplinary challenge. To handle HTD data effectively and efficiently, we have developed a distributed virtual screening data management system (DVSDMS) in which the data handling and the distribution of jobs are realized by the open-source structured query language database software MySQL. The essential concept of DVSDMS is the separation of the data management from the docking and ranking applications. DVSDMS can be used to dock millions of molecules effectively, monitor the process in real time, analyze docking results promptly, and process up to 10(8) poses by energy ranking techniques. In an HTD campaign to identify kinase inhibitors a low cost Linux PC has allowed DVSDMS to efficiently assign the workload to more than 500 computing clients. Notably, in a stress test of DVSDMS that emulated a large number of clients, about 60 molecules per second were distributed to the clients for docking, which indicates that DVSDMS can run efficiently on very large compute cluster (up to about 40000 cores). PMID:19072299

  6. 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.

  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. 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.

  9. Adaptive load sharing in heterogeneous distributed systems

    NASA Astrophysics Data System (ADS)

    Mirchandaney, Ravi; Towsley, Don; Stankovic, John A.

    1990-08-01

    In this paper, we study the performance characteristics of simple load sharing algorithms for heterogeneous distributed systems. We assume that nonnegligible delays are encountered in transferring jobs from one node to another. We analyze the effects of these delays on the performance of two threshold-based algorithms called Forward and Reverse. We formulate queuing theoretic models for each of the algorithms operating in heterogeneous systems under the assumption that the job arrival process at each node in Poisson and the service times and job transfer times are exponentially distributed. The models are solved using the Matrix-Geometric solution technique. These models are used to study the effects of different parameters and algorithm variations on the mean job response time: e.g., the effects of varying the thresholds, the impact of changing the probe limit, the impact of biasing the probing, and the optimal response times over a large range of loads and delays. Wherever relevant, the results of the models are compared with the M/M/ 1 model, representing no load balancing (hereafter referred to as NLB), and the M/M/K model, which is an achievable lower bound (hereafter referred to as LB).

  10. Distributed control system for turbine engines

    SciTech Connect

    Shaffer, P.L.

    1999-01-01

    A distributed control system (DCS) for a turbine engine has been demonstrated and tested, consisting of prototype electronic interface units (EIUs) connected to data and power busses. In the DCS, a central control computer communicated with smart sensors and smart actuators via a 2.5 megabit/sec digital data bus, using the Fieldbus protocol. Power was distributed to the smart devices as 100 kHz 100V peak AC, allowing light, simple power converters at each smart device. All smart sensors, smart actuators, and cables were dual redundant. The smart actuators received position demand from the central control computer, exchanged data between channels to provide local redundancy management, closed the position loop locally, and reported actuator position to the central controller. Smart sensors converted sensed signals to digital values in engineering units, and performed local built-in tests. Testing of the DCS was done in a closed-loop simulation with an engine model. Frequency response of the DCS was almost identical with the conventional system.

  11. WTe 2 surfaces in UHV-STM image formation and analysis of point defect structures

    NASA Astrophysics Data System (ADS)

    Crossley, J. A. A.; Sofield, C. J.; Myhra, S.

    1997-05-01

    The layered semi-metallic T d phase of WTe 2 has been examined by STM in UHV. The effects of transient transfer of tip apex atom from/to the surface (W ↔ Te exchange) on the imaging conditions have been observed; the effects demonstrate the inadequacy of the Tersoff-Hamann approximation to the description of the tunnelling process. Two distinctly different point-defect configurations have been observed, assigned tentatively to vacancies in either "top" or "bottom" Te sites. Anomalous image conditions were observed frequently; these have been ascribed to delamination of the structure, and consequential transfer of the tunnelling to a delocalised internal gap, with the image representing the averaged tunnel current during relative displacements of two neighbouring Te planes.

  12. Oxidation of Pt(111) by ozone (O 3) under UHV conditions

    NASA Astrophysics Data System (ADS)

    Saliba, N. A.; Tsai, Y.-L.; Panja, C.; Koel, B. E.

    1999-01-01

    Ozone (O 3) is a reactive oxidant, creating high effective oxygen pressures under ultra-high vacuum (UHV) conditions. Large oxygen concentrations up to ΘO=2.4 ML were produced by ozone exposure on Pt(111) at 300 K and analyzed using temperature-programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED). O 2 desorption occurs in broad TPD peaks that shift from 814 to 558 K as the oxygen coverage increases from 0.03 to 0.95 ML. For coverages of ΘO≥1.2 ML, "undercutting" of the desorption curves occurs, along with a narrowing and shift to higher temperature, such that O 2 desorption occurs in a sharp (23 K wide) peak at 708 K at ΘO=2.4 ML. LEED shows a (2×2) pattern for ΘO near 0.25 ML, but then only a (1×1) pattern between 0.3 and 1.2 ML. For oxygen coverages larger than 1.2 ML, the Pt(111) surface is disordered. Using the leading edge method, we estimate that the desorption activation energy decreases from 45 to 20 kcal mol -1 with increased oxygen concentration for 0< ΘO<1.2 ML, and thereafter increases with increasing concentration to 38 kcal mol -1 at ΘO=2.4 ML. We interpret the O 2 desorption curves for ΘO>1.2 ML as arising from decomposition of particles of platinum oxide of increasing size near the surface. A very weakly bound state of oxygen also exists at high ΘO and desorbs at 390 K. Oxidized platinum is reduced upon heating to Pt metal in the temperature range of 674-708 K in UHV.

  13. 49 CFR 191.11 - Distribution system: Annual report.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Distribution system: Annual report. 191.11 Section... § 191.11 Distribution system: Annual report. (a) General. Except as provided in paragraph (b) of this section, each operator of a distribution pipeline system must submit an annual report for that system...

  14. SOFC combined cycle systems for distributed generation

    SciTech Connect

    Brown, R.A.

    1997-05-01

    The final phase of the tubular SOFC development program will focus on the development and demonstration of pressurized solid oxide fuel cell (PSOFC)/gas turbine (GT) combined cycle power systems for distributed power applications. The commercial PSOFC/GT product line will cover the power range 200 kWe to 50 MWe, and the electrical efficiency for these systems will range from 60 to 75% (net AC/LHV CH4), the highest of any known fossil fueled power generation technology. The first demonstration of a pressurized solid oxide fuel cell/gas turbine combined cycle will be a proof-of-concept 250 kWe PSOFC/MTG power system consisting of a single 200 kWe PSOFC module and a 50 kWe microturbine generator (MTG). The second demonstration of this combined cycle will be 1.3 MWe fully packaged, commercial prototype PSOFC/GT power system consisting of two 500 kWe PSOFC modules and a 300 kWe gas turbine.

  15. Waiting time distribution for continuous stochastic systems.

    PubMed

    Gernert, Robert; Emary, Clive; Klapp, Sabine H L

    2014-12-01

    The waiting time distribution (WTD) is a common tool for analyzing discrete stochastic processes in classical and quantum systems. However, there are many physical examples where the dynamics is continuous and only approximately discrete, or where it is favourable to discuss the dynamics on a discretized and a continuous level in parallel. An example is the hindered motion of particles through potential landscapes with barriers. In the present paper we propose a consistent generalization of the WTD from the discrete case to situations where the particles perform continuous barrier crossing characterized by a finite duration. To this end, we introduce a recipe to calculate the WTD from the Fokker-Planck (Smoluchowski) equation. In contrast to the closely related first passage time distribution (FPTD), which is frequently used to describe continuous processes, the WTD contains information about the direction of motion. As an application, we consider the paradigmatic example of an overdamped particle diffusing through a washboard potential. To verify the approach and to elucidate its numerical implications, we compare the WTD defined via the Smoluchowski equation with data from direct simulation of the underlying Langevin equation and find full consistency provided that the jumps in the Langevin approach are defined properly. Moreover, for sufficiently large energy barriers, the WTD defined via the Smoluchowski equation becomes consistent with that resulting from the analytical solution of a (two-state) master equation model for the short-time dynamics developed previously by us [Phys. Rev. E 86, 061135 (2012)]. Thus, our approach "interpolates" between these two types of stochastic motion. We illustrate our approach for both symmetric systems and systems under constant force. PMID:25615052

  16. 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

  17. The Unidata LDM Data Distribution System

    NASA Astrophysics Data System (ADS)

    Emmerson, S.; Yoksas, T. C.; Weber, W. J.; Schmidt, M.

    2010-12-01

    The Unidata LDM is a near real-time, event-driven system for transmitting frequently-generated data-products, 24/7, from a producer to multiple subscribers using the Internet. Once received, a data-product is processed according to user specifications. A data-product can be anything up to 4 gigabytes in size. Downstream LDM-s register a regular expression based selection predicate with upstream LDM-s. Network topologies include point-to-point, star, and tree. Based on ONC RPC, the LDM system is extremely robust and efficient. Since its initial release in 1994, a network of LDM-s called the Internet Data Distribution (IDD) system has been the primary means by which many if not most Earth Sciences departments in the US obtain and process meteorological data (up to 20 GB/hour and 250k products/hour) with latencies measured in seconds or less. Data-products include numerical model output, radar data, WMO bulletins, and lightning data. Users of the LDM also include the international atmospheric science university community, NOAA, NASA, USGS, the US military, ECMWF, and the meteorological agencies of China, Australia, Brazil, South Korea, and Vietnam. The LDM is the highest volume advanced application on Internet-2 (currently averaging 27 terabytes per week). The LDM history and architecture is presented together with an analysis of its strengths and weaknesses.

  18. The Hazards Data Distribution System update

    USGS Publications Warehouse

    Jones, Brenda K.; Lamb, Rynn

    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/

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

    Energy Science and Technology Software Center (ESTSC)

    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

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

    SciTech Connect

    McEver, M.

    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 to 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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.

  6. 49 CFR 191.9 - Distribution system: Incident report.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Distribution system: Incident report. 191.9... CONDITION REPORTS § 191.9 Distribution system: Incident report. (a) Except as provided in paragraph (c) of this section, each operator of a distribution pipeline system shall submit Department of...

  7. 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... maintenance: Distribution systems. (a) Each valve, the use of which may be necessary for the safe operation of a distribution system, must be checked and serviced at intervals not exceeding 15 months, but...

  8. 49 CFR 191.9 - Distribution system: Incident report.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Distribution system: Incident report. 191.9... CONDITION REPORTS § 191.9 Distribution system: Incident report. (a) Except as provided in paragraph (c) of this section, each operator of a distribution pipeline system shall submit Department of...

  9. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 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...

  10. 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...

  11. 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...

  12. 46 CFR 28.855 - Electrical distribution systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 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...

  13. 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...

  14. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 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...

  15. 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...

  16. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 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...

  17. 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... 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...

  18. 47 CFR 73.626 - DTV distributed transmission systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 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...

  19. 47 CFR 73.626 - DTV distributed transmission systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 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, 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...

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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. PMID:26409148

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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)

  12. 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…

  13. 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...

  14. 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)

  15. Interaction measurements between a tip and a sample in proximity regions controlled by tunneling current in a UHV STM AFM

    NASA Astrophysics Data System (ADS)

    Arai, Toyoko; Tomitori, Masahiko

    1999-04-01

    The interaction force-distance curves between a tip and a sample surface in close proximity were measured by logarithmically changing a tunneling current passing through them with a ultrahigh vacuum scanning tunneling microscopy-atomic force microscopy (UHV STM-AFM). Since the tunneling current changes exponentially with the separation between the tip and the sample, the separation can be controlled precisely and linearly by modulating a logarithmic target value fed into the STM feedback circuit to be a triangular waveform. A piezoresistive cantilever with a conductive Si tip was used after cleaning the tip by heating it in the UHV chamber. As a preliminary result, force-separation curves with reversible and irreversible jumps in close proximity were presented.

  16. DISFIT: A DISTRIBUTION FITTING SYSTEM 1. DISCRETE DISTRIBUTIONS, A USER'S GUIDE

    EPA Science Inventory

    The DISFIT system is a series of programs and subroutines to fit distributions to data. This first volume describes the routines to fit discrete distributions. The distributions included are the binomial, truncated binomial, mixture of two binomials, beta binomial, Poisson, trunc...

  17. STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Presented within this 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. ipeline cost data include costs for commonly utilized pipe mate...

  18. 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...

  19. A Study on Support System for Distributed Simulation System of Manufacturing Systems Using HLA

    NASA Astrophysics Data System (ADS)

    Hibino, Hironori; Fukuda, Yoshiro

    In this paper, we firstly describe outlines of the developed distributed simulation system using HLA and the developed synchronization method in the past. We clarify requirement contrivances of the user support system. We explain requirement functions of the user support system that is premised on using the developed distributed simulation system and the developed synchronization method. We propose and develop the user support system. The case study was then carried out to evaluate the performance of the cooperative work.

  20. 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.

  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. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 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...

  3. 24 CFR 3280.609 - Water distribution systems.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 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...

  4. 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...

  5. Computational methods for the control of distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Cliff, E. M.; Powers, R. K.

    1986-01-01

    Finite dimensional approximation schemes that work well for distributed parameter systems are often not suitable for the analysis and implementation of feedback control systems. The relationship between approximation schemes for distributed parameter systems and their application to optimal control problems is discussed. A numerical example is given.

  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. An oceanographic radiance distribution camera system.

    PubMed

    Smith, R C; Austin, R W; Tyler, J E

    1970-09-01

    An oceanographic optical instrument has been designed and constructed to record the radiance distribution of natural radiant energy underwater. The instrument contains two cameras placed back-to-back, each equipped with a fisheye (180 degrees field of view) lens and is fabricated so that film can be exposed by remote control. The instrument is designed to operate at depths up to 100 m. Values of underwater radiance can be obtained from the exposed films by means of photographic photometry. Radiance distributions obtained in natural waters will provide basic information needed for the study and solution of several problems in optical oceanography. First, the radiance distribution is an important input for the study of the interaction of electromagnetic radiation with the sea. From the distribution of radiance in the natural light fields in the ocean, many of the important optical properties which relate to radiative transfer processes in the ocean can be calculated. Second, from these optical properties one can compute the magnitude of the deterioration of image contrast of submerged objects and thus furnish information for the study and solution of underwater visibility problems, which include problems in underwater television and photography. Finally, since radiant energy is critical to the beginning of the marine food chain through photosynthetic plankton, radiance distribution measurements will provide information of fundamental importance to the problem of primary productivity in natural waters. PMID:20094190

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. ESTIMATING COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The issue of economic effects and the cost of water supply is a continuing factor in implementing the Safe Drinking Water Act. The cost of distributing water to the final user after it has been treated is of growing concern as well as its quality. There are a significant number o...

  14. 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.

  15. Performance analysis of static locking in distributed database systems

    SciTech Connect

    Shyu, S.C. ); Li, V.O.K. . Dept. of Electrical Engineering)

    1990-06-01

    Numerous performance models have been proposed for locking algorithms in centralized database systems, but few have been developed for distributed ones. Existing results on distributed locking usually ignore the deadlock problem so as to simplify the analysis. In this paper, a new performance model for static locking in distributed database systems is developed.A queuing model is used to approximate static locking in distributed database systems without deadlocks. Then a random graph model is proposed to find the deadlock probability of each transaction. The above two models are integrated, so that given the transaction arrival rate, the response time and the effective throughput can be calculated.

  16. 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.

  17. 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.

  18. System for measuring spatial distribution of ejected droplets, a concept

    NASA Technical Reports Server (NTRS)

    Ayvazian, R. A.

    1968-01-01

    System measures the spatial distribution of high-velocity droplets ejected from a nozzle or spray gun. The system employs an electrically resistive grid as the sensing screen, electrical leads, and a signal scanner such as a cathode ray tube.

  19. 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.

  20. Distributed Information System Development: Review of Some Management Issues

    NASA Astrophysics Data System (ADS)

    Mishra, Deepti; Mishra, Alok

    Due to the proliferation of the Internet and globalization, distributed information system development is becoming popular. In this paper we have reviewed some significant management issues like process management, project management, requirements management and knowledge management issues which have received much attention in distributed development perspective. In this literature review we found that areas like quality and risk management issues could get only scant attention in distributed information system development.

  1. 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.

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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... must be only one connection to ground, regardless of the number of power sources. This ground... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the...

  8. 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... ground, regardless of the number of power sources. This ground connection must be at the switchboard or at the common ground plate, which must be accessible. (b) Each propulsion, power, lighting,...

  9. 46 CFR 28.360 - Electrical distribution systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Construction on or After or Which Undergo a Major Conversion Completed on or After September 15, 1991, and That... electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor grounded. (b) A grounded electrical distribution system must have only one connection to ground....

  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, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 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, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 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. 49 CFR 192.747 - Valve maintenance: Distribution systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 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...

  14. 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,…

  15. An Applet-based Anonymous Distributed Computing System.

    ERIC Educational Resources Information Center

    Finkel, David; Wills, Craig E.; Ciaraldi, Michael J.; Amorin, Kevin; Covati, Adam; Lee, Michael

    2001-01-01

    Defines anonymous distributed computing systems and focuses on the specifics of a Java, applet-based approach for large-scale, anonymous, distributed computing on the Internet. Explains the possibility of a large number of computers participating in a single computation and describes a test of the functionality of the system. (Author/LRW)

  16. 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...

  17. 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...

  18. 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.

  19. 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…

  20. 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...

  1. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., 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...

  2. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., 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...

  3. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., 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...

  4. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., 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 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...

  6. 14 CFR 29.1355 - Distribution system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., 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...

  7. 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...

  8. 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...

  9. 14 CFR 25.1355 - Distribution system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., 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...

  10. 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

  11. 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.

  12. 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.

  13. Time generation and distribution system for a military national synchronization

    NASA Astrophysics Data System (ADS)

    Mourier, V.

    1992-06-01

    The requirements, concept, and principle of a French air force time generation and distribution system are presented. The system provides homogeneous dating of events throughout the country. It generates and distributes time codes and precise frequency used for high precision measurements, telecommunications, etc. Accordingly the need is to provide on each operational site an accurate and stable time reference based on UTC time scale. The system consists of a common reference (GPS (Global Positioning System)) independent clocks and time distribution that provides time to all the user equipment on each operational site.

  14. Asymmetric charge distributions in planar bilayer systems.

    PubMed Central

    McQuarrie, D A; Mulás, P

    1977-01-01

    Using the simple argument based on irreversible thermodynamics and the Gouy-Chapman theory of the double layer, we show that the equilibrium distribution of charged lipid molecules between the two surfaces of a bilayer is asymmetric if the two solutions bathing the surfaces have the same ionic strength but contain ions of different valencies. For example, if one bathing solution contains 0.10 M NaCl and the other contains 0.70 M NaCl and 0.10 M CaCl2, the ratio of charged lipid molecules of the two surfaces in a membrane that contains 50% total negative lipids is 1.46, leading to a transbilayer potential of 18 mV. A complete set of such numerical results is presented in four figures. PMID:836930

  15. Asymmetric charge distributions in planar bilayer systems.

    PubMed

    McQuarrie, D A; Mulás, P

    1977-02-01

    Using the simple argument based on irreversible thermodynamics and the Gouy-Chapman theory of the double layer, we show that the equilibrium distribution of charged lipid molecules between the two surfaces of a bilayer is asymmetric if the two solutions bathing the surfaces have the same ionic strength but contain ions of different valencies. For example, if one bathing solution contains 0.10 M NaCl and the other contains 0.70 M NaCl and 0.10 M CaCl2, the ratio of charged lipid molecules of the two surfaces in a membrane that contains 50% total negative lipids is 1.46, leading to a transbilayer potential of 18 mV. A complete set of such numerical results is presented in four figures. PMID:836930

  16. 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

  17. 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.

  18. 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.

  19. 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.

  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. 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.

  2. 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.

  3. 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.

  4. Optimal dynamic control of resources in a distributed system

    NASA Technical Reports Server (NTRS)

    Shin, Kang G.; Krishna, C. M.; Lee, Yann-Hang

    1989-01-01

    The authors quantitatively formulate the problem of controlling resources in a distributed system so as to optimize a reward function and derive optimal control strategies using Markov decision theory. The control variables treated are quite general; they could be control decisions related to system configuration, repair, diagnostics, files, or data. Two algorithms for resource control in distributed systems are derived for time-invariant and periodic environments, respectively. A detailed example to demonstrate the power and usefulness of the approach is provided.

  5. 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.

  6. Distributed System of Processing of Data of Physical Experiments

    NASA Astrophysics Data System (ADS)

    Nazarov, A. A.; Moiseev, A. N.

    2014-11-01

    Complication of physical experiments and increasing volumes of experimental data necessitate the application of supercomputer and distributed computing systems for data processing. Design and development of such systems, their mathematical modeling, and investigation of their characteristics and functional capabilities is an urgent scientific and practical problem. In the present work, the characteristics of operation of such distributed system of processing of data of physical experiments are investigated using the apparatus of theory of queuing networks.

  7. A Study on a New Distribution System Planning with Considering Distributed Generators Installation

    NASA Astrophysics Data System (ADS)

    Koeda, Kazuhiko; Zoka, Yoshifumi; Ueyama, Teppei; Yorino, Naoto; Sasaki, Hiroshi

    This paper proposes a new framework of distribution system planning under the condition of mass installed Distributed Generators (DGs). At present, distribution system planners do not pay much attention to the interconnection of DGs. However, if some DGs can supply power instead of conventional power stations, they will give a significant impact. The planners will have a new option to build a network system plan without unnecessary investment to distribution networks. In this study, an objective function for distribution system planning is formulated to obtain maximum profits for utilities, and the authors discuss reduction of the utilities' investment cost and distribution system loss for installation of DGs. In addition, the authors propose a solution method using a genetic algorithm technique in order to find quasi-optimal solutions for large scale problems. Furthermore, the authors also discuss the connection tariff in order to increase the utilization rate of distribution networks. The advantage of the proposed method is demonstrated through several numerical simulations with successful results.

  8. Recalling data in a distributed processing system

    SciTech Connect

    Kamionka, H.E.

    1983-07-01

    A multihost system includes programming controls that migrate aged data from the primary external data storage DASD (direct-access storage device) to magnetic recording tape for long-term storage. The author describes an independent recall operation which retrieves tape stored data for a particular host.

  9. Distributive Processing Issues in Education Information Systems.

    ERIC Educational Resources Information Center

    Ender, Philip B.

    This is one of a series of reports based on an ongoing reality test of systemic evaluation for instructional decision making. This feasibility study is being carried out by the Center for the Study of Evaluation with the Laboratory in School and Community Relations at a suburban Los Angeles high school (called Site A). Viewing a school as a…

  10. 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.

  11. 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.

  12. 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.

  13. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV

    SciTech Connect

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P.

    2015-12-15

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  14. 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.

  15. 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.

  16. Structured pedigree information for distributed fusion systems

    NASA Astrophysics Data System (ADS)

    Arambel, Pablo O.

    2008-04-01

    One of the most critical challenges in distributed data fusion is the avoidance of information double counting (also called "data incest" or "rumor propagation"). This occurs when a node in a network incorporates information into an estimate - e.g. the position of an object - and the estimate is injected into the network. Other nodes fuse this estimate with their own estimates, and continue to propagate estimates through the network. When the first node receives a fused estimate from the network, it does not know if it already contains its own contributions or not. Since the correlation between its own estimate and the estimate received from the network is not known, the node can not fuse the estimates in an optimal way. If it assumes that both estimates are independent from each other, it unknowingly double counts the information that has already being used to obtain the two estimates. This leads to overoptimistic error covariance matrices. If the double-counting is not kept under control, it may lead to serious performance degradation. Double counting can be avoided by propagating uniquely tagged raw measurements; however, that forces each node to process all the measurements and precludes the propagation of derived information. Another approach is to fuse the information using the Covariance Intersection (CI) equations, which maintain consistent estimates irrespective of the cross-correlation among estimates. However, CI does not exploit pedigree information of any kind. In this paper we present an approach that propagates multiple covariance matrices, one for each uncorrelated source in the network. This is a way to compress the pedigree information and avoids the need to propagate raw measurements. The approach uses a generalized version of the Split CI to fuse different estimates with appropriate weights to guarantee the consistency of the estimates.

  17. 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

  18. 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.

  19. Distributed-Computer System Optimizes SRB Joints

    NASA Technical Reports Server (NTRS)

    Rogers, James L., Jr.; Young, Katherine C.; Barthelemy, Jean-Francois M.

    1991-01-01

    Initial calculations of redesign of joint on solid rocket booster (SRB) that failed during Space Shuttle tragedy showed redesign increased weight. Optimization techniques applied to determine whether weight could be reduced while keeping joint closed and limiting stresses. Analysis system developed by use of existing software coupling structural analysis with optimization computations. Software designed executable on network of computer workstations. Took advantage of parallelism offered by finite-difference technique of computing gradients to enable several workstations to contribute simultaneously to solution of problem. Key features, effective use of redundancies in hardware and flexible software, enabling optimization to proceed with minimal delay and decreased overall time to completion.

  20. 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...

  1. 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.

  2. 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.

  3. [Intelligent distributed system of population cancer screening].

    PubMed

    Barchuk, A A; Podolsky, M D; Gaidukov, V S; Kuznetsov, V I; Arseniev, A I; Kanaev, S V; Barchuk, A S; Levchenko, E V; Merabishvili, V M; Kostitsyn, K A; Beloglazova, O V; Filochkina, A V; Gagua, K E; Preis, V G; Tarakanov, S A

    2015-01-01

    This review summarizes data dedicated to improving the efficiency of screening of malignant tumors through the use of modern information and telecommunication technologies. It is showed that currently available software solutions in the field of medical imaging is not enough adapted for population screening. So far there is no single standard that defines checking algorithms of data processing at certain controlled conditions. The most expected result will be the organization of information centralized storage, sharing diagnostic data, providing broad access to them, automated analysis and selection of diagnostically significant results through the software. The basic requirements for the development of self-learning systems for intelligent processing array of heterogeneous data through the use of technologies of semantic networks are provided. PMID:26571818

  4. 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.

  5. 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.

  6. 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.

  7. Automatic Management of Parallel and Distributed System Resources

    NASA Technical Reports Server (NTRS)

    Yan, Jerry; Ngai, Tin Fook; Lundstrom, Stephen F.

    1990-01-01

    Viewgraphs on automatic management of parallel and distributed system resources are presented. Topics covered include: parallel applications; intelligent management of multiprocessing systems; performance evaluation of parallel architecture; dynamic concurrent programs; compiler-directed system approach; lattice gaseous cellular automata; and sparse matrix Cholesky factorization.

  8. 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.

  9. Abstractions for Fault-Tolerant Distributed System Verification

    NASA Technical Reports Server (NTRS)

    Pike, Lee S.; Maddalon, Jeffrey M.; Miner, Paul S.; Geser, Alfons

    2004-01-01

    Four kinds of abstraction for the design and analysis of fault tolerant distributed systems are discussed. These abstractions concern system messages, faults, fault masking voting, and communication. The abstractions are formalized in higher order logic, and are intended to facilitate specifying and verifying such systems in higher order theorem provers.

  10. 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.

  11. 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.

  12. 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.

  13. Programming fault-tolerant distributed systems in Ada

    NASA Technical Reports Server (NTRS)

    Voigt, Susan J.

    1985-01-01

    Viewgraphs on the topic of programming fault-tolerant distributed systems in the Ada programming language are presented. Topics covered include project goals, Ada difficulties and solutions, testbed requirements, and virtual processors.

  14. 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.

  15. Job Measurement Standards and Workload Planning in Distribution System Work.

    ERIC Educational Resources Information Center

    American Water Works Association Journal, 1979

    1979-01-01

    This report describes methods and benefits of applying standard work measurement and planning techniques to water distribution system work. The three sections of the report discuss: a general work standards survey; application; and consideration of benefits. (CS)

  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. 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...

  18. EPANET - AN ADVANCED WATER QUALITY MODELING PACKAGE FOR DISTRIBUTION SYSTEMS

    EPA Science Inventory

    EPANET is a third generation software package for modeling water quality within drinking water distribution systems. he program performs extended period simulation of hydraulic and water quality conditions within pressurized pipe networks. n addition to substance concentration wa...

  19. 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.

  20. Design and implementation of distributed information retrieval system

    NASA Astrophysics Data System (ADS)

    Liu, Haishu

    2013-07-01

    For the lack of robustness and scalability in the existing centralized search engine implementation, this paper presents a distributed information retrieval service system model based on search engine technology. This model can real-t imely monitor the specified information source to collect the latest informat ion in the first time and process it, for users to search, and the design is distributed, can make the system have good robustness and scalability through mutual cooperation of background nodes.

  1. 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.

  2. 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.

  3. cc domains with intrinsic screening and absence of closure domains in atomically ordered BaTiO3 in UHV

    NASA Astrophysics Data System (ADS)

    Watanabe, Y.; Kaku, S.; Nakamura, K.

    2010-03-01

    cc domains have been observed in ordinary environments, where extraneous screening hampers rigorous comparison with theories. Indeed, recent theories predict closure domains in the absence of extraneous screening. Therefore, we performed simultaneous topographic, electrostatic and piezoelectric imaging of atomically clean, free surface of BaTiO3 single crystal by AFM operated in ultra high vacuum (UHV).footnotetextS. Kaku et al., J.Kor.Phys.Soc.55,799(2009) BaTiO3 surface retains stoichiometry in UHV because of the absence of volatile elements (Pb, Bi, Li) and low TC The surface cleanness is confirmed by the detection of chemical bonding. Three imaging methods verified the assignment of ac and cc domains, which is consistent with conventional theory and experiments. These ac and cc domains change reversibly by weak electric field of 2kV/cm at RT. In addition, the temperature dependence of the domains agrees with convention theories. These observations prove the absence of dominating control of defects and impurities on the observed domains. The sole deviation is the reduction of the potential difference to 1/30 of the conventional theories. The described intrinsic nature of the domains indicates an intrinsic screening in cc domains, which is consistent with the intrinsic surface carrier layer on ferroelectrics.footnotetextWatanabe et al. PRL86332(2001), PRB57,789(1998)

  4. 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.

  5. Levy distribution in many-particle quantum systems

    SciTech Connect

    Ponomarev, A. V.; Denisov, S.; Haenggi, P.

    2010-04-15

    The Levy distribution, previously used to describe complex behavior of classical systems, is shown to characterize that of quantum many-body systems. Using two complimentary approaches, the canonical and grand-canonical formalisms, we discovered that the momentum profile of a Tonks-Girardeau gas - a one-dimensional gas of N impenetrable (hard-core) bosons-harmonically confined on a lattice at finite temperatures obeys a Levy distribution. Finally, we extend our analysis to different confinement setups and demonstrate that the tunable Levy distribution properly reproduces momentum profiles in experimentally accessible regions. Our finding allows for calibration of complex many-body quantum states by using a unique scaling exponent.

  6. 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.

  7. A Multi-agent Approach to Distribution System Restoration

    NASA Astrophysics Data System (ADS)

    Nagata, Takeshi; Tao, Yasuhiro; Sasaki, Hiroshi; Fujita, Hideki

    This paper proposes a multi-agent approach to decentralized power system restoration for a distribution system network. The proposed method consists of several Feeder Agents (FAGs) and Load Agents (LAGs). LAG corresponds to the customer load, while a FAG is developed to act as a manager for the decision process. From the simulation results, it can be seen the proposed multi-agent system could reach the right solution by making use of only local information. This means that the proposed multi-agent restoration system is a promising approach to more large-scale distribution networks.

  8. 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.

  9. 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.

  10. Comparing Different Fault Identification Algorithms in Distributed Power System

    NASA Astrophysics Data System (ADS)

    Alkaabi, Salim

    A power system is a huge complex system that delivers the electrical power from the generation units to the consumers. As the demand for electrical power increases, distributed power generation was introduced to the power system. Faults may occur in the power system at any time in different locations. These faults cause a huge damage to the system as they might lead to full failure of the power system. Using distributed generation in the power system made it even harder to identify the location of the faults in the system. The main objective of this work is to test the different fault location identification algorithms while tested on a power system with the different amount of power injected using distributed generators. As faults may lead the system to full failure, this is an important area for research. In this thesis different fault location identification algorithms have been tested and compared while the different amount of power is injected from distributed generators. The algorithms were tested on IEEE 34 node test feeder using MATLAB and the results were compared to find when these algorithms might fail and the reliability of these methods.

  11. 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.

  12. 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.

  13. MAC, A System for Automatically IPR Identification, Collection and Distribution

    NASA Astrophysics Data System (ADS)

    Serrão, Carlos

    Controlling Intellectual Property Rights (IPR) in the Digital World is a very hard challenge. The facility to create multiple bit-by-bit identical copies from original IPR works creates the opportunities for digital piracy. One of the most affected industries by this fact is the Music Industry. The Music Industry has supported huge losses during the last few years due to this fact. Moreover, this fact is also affecting the way that music rights collecting and distributing societies are operating to assure a correct music IPR identification, collection and distribution. In this article a system for automating this IPR identification, collection and distribution is presented and described. This system makes usage of advanced automatic audio identification system based on audio fingerprinting technology. This paper will present the details of the system and present a use-case scenario where this system is being used.

  14. 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.

  15. Computational methods for the control of distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Cliff, E. M.; Powers, R. K.

    1985-01-01

    It is shown that care must be taken to ensure that finite dimensional approximations of distributed parameter systems preserve important system properties (i.e., controllability, observability, stabilizability, detectability, etc.). It is noted that, if the particular scheme used to construct the finite dimensional model does not take into account these system properties, the model may not be suitable for control design and analysis. These ideas are illustrated by a simple example, i.e., a cable-spring-mass system.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Electrical Distribution System (EDS) and Caution and Warning System (CWS)

    NASA Technical Reports Server (NTRS)

    Mcclung, T.

    1975-01-01

    An astronaut caution and warning system is described which monitors various life support system parameters and detects out-of-range parameter conditions. The warning system generates a warning tone and displays the malfunction condition to the astronaut along with the proper corrective procedures required.

  1. 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 ...

  2. Distributed Collector Systems (DCS) for the medium temperature range

    NASA Astrophysics Data System (ADS)

    Kalt, A. C.

    1982-11-01

    The basic layout of a distributed collector system (DCS) is described and questions concerning design are discussed. Plant designs and performance data for four DCS systems are presented. Energy storage techniques, the power conversion cycle, and heat transfer subsystems are addressed.

  3. 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

  4. Development of a distribution system for measuring nozzle integrative parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The experimental system used in this study was equipped with sensors and computer-controlled processing technology. This system was used in the measurement of major performance parameters such as pressure, flux, spray angle, spray distribution character of the nozzle and its integrative performance...

  5. Clouds: A support architecture for fault tolerant, distributed systems

    NASA Technical Reports Server (NTRS)

    Dasgupta, P.; Leblanco, R. J., Jr.

    1986-01-01

    Clouds is a distributed operating system providing support for fault tolerance, location independence, reconfiguration, and transactions. The implementation paradigm uses objects and nested actions as building blocks. Subsystems and applications that can be supported by Clouds to further enhance the performance and utility of the system are also discussed.

  6. 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.…

  7. A portable scanning system for evaluation of spray deposit distribution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preventing over- or under–spray applications on intended targets require a system to rapidly measure spray coverage and provide spray quality feedback information. A portable scanning system was developed that could quickly evaluate spray deposit distribution and coverage area on deposit collectors ...

  8. 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.

  9. Porter-Thomas distribution in unstable many-body systems

    SciTech Connect

    Volya, Alexander

    2011-04-15

    We use the continuum shell model approach to explore the resonance width distribution in unstable many-body systems. The single-particle nature of a decay, the few-body character of the interaction Hamiltonian, and the collectivity that emerges in nonstationary systems due to the coupling to the continuum of reaction states are discussed. Correlations between the structures of the parent and daughter nuclear systems in the common Fock space are found to result in deviations of decay width statistics from the Porter-Thomas distribution.

  10. Discrete Wavelet Transform for Fault Locations in Underground Distribution System

    NASA Astrophysics Data System (ADS)

    Apisit, C.; Ngaopitakkul, A.

    2010-10-01

    In this paper, a technique for detecting faults in underground distribution system is presented. Discrete Wavelet Transform (DWT) based on traveling wave is employed in order to detect the high frequency components and to identify fault locations in the underground distribution system. The first peak time obtained from the faulty bus is employed for calculating the distance of fault from sending end. The validity of the proposed technique is tested with various fault inception angles, fault locations and faulty phases. The result is found that the proposed technique provides satisfactory result and will be very useful in the development of power systems protection scheme.

  11. Reflexive reasoning for distributed real-time systems

    NASA Technical Reports Server (NTRS)

    Goldstein, David

    1994-01-01

    This paper discusses the implementation and use of reflexive reasoning in real-time, distributed knowledge-based applications. Recently there has been a great deal of interest in agent-oriented systems. Implementing such systems implies a mechanism for sharing knowledge, goals and other state information among the agents. Our techniques facilitate an agent examining both state information about other agents and the parameters of the knowledge-based system shell implementing its reasoning algorithms. The shell implementing the reasoning is the Distributed Artificial Intelligence Toolkit, which is a derivative of CLIPS.

  12. New security infrastructure model for distributed computing systems

    NASA Astrophysics Data System (ADS)

    Dubenskaya, J.; Kryukov, A.; Demichev, A.; Prikhodko, N.

    2016-02-01

    At the paper we propose a new approach to setting up a user-friendly and yet secure authentication and authorization procedure in a distributed computing system. The security concept of the most heterogeneous distributed computing systems is based on the public key infrastructure along with proxy certificates which are used for rights delegation. In practice a contradiction between the limited lifetime of the proxy certificates and the unpredictable time of the request processing is a big issue for the end users of the system. We propose to use unlimited in time hashes which are individual for each request instead of proxy certificate. Our approach allows to avoid using of the proxy certificates. Thus the security infrastructure of distributed computing system becomes easier for development, support and use.

  13. Interconnecting Single-Phase Generation to the Utility Distribution System

    SciTech Connect

    Dugan, R.C.

    2001-12-05

    One potentially large source of underutilized distributed generation (DG) capacity exists in single-phase standby backup gensets on farms served from single-phase feeder laterals. Utilizing the excess capacity would require interconnecting to the utility system. Connecting single-phase gensets to the utility system presents some interesting technical issues that have not been previously investigated. This paper addresses several of the interconnection issues associated with this form of DG including voltage regulation, harmonics, overcurrent protection, and islanding. A significant amount of single-phase DG can be accommodated by the utility distribution system, but there are definite limitations due to the nature and location of the DG. These limitations may be more restrictive than is commonly assumed for three-phase DG installed on stronger parts of the electric distribution system.

  14. 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.

  15. 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.

  16. Anisotropy of force distributions in sheared soft-particle systems

    NASA Astrophysics Data System (ADS)

    Boberski, Jens; Shaebani, M. Reza; Wolf, Dietrich E.

    2014-11-01

    In this numerical study, measurements of the contact forces inside a periodic two-dimensional sheared system of soft frictional particles are reported. The distribution \\text{P}(fn) of normalized normal forces fn=Fn/< Fn > exhibits a gradual broadening with the increase of the pure shear deformation γ, leading to a slower decay for large forces. The process, however, slows down and \\text{P}(fn) approaches an invariant shape at high γ. By introducing the joint probability distribution \\text{P}(fn,α) in sheared configurations, it is shown that for a fixed direction α, the force distribution decays faster than exponentially even in a sheared system. The overall broadening can be attributed to the averaging over different directions in the presence of shear-induced stress anisotropy. The distribution of normalized tangential forces almost preserves its shape for arbitrary applied strain.

  17. 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

  18. 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.

  19. 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.

  20. Reliability analysis and optimization in the design of distributed systems

    SciTech Connect

    Hariri, S.

    1986-01-01

    Reliability measures and efficient evaluation algorithms are presented to aid in designing reliable distributed systems. The terminal reliability between a pair of computers is a good measure in computer networks. For distributed systems, to capture more effectively the redundancy in resources, such as programs and files, two new reliability measures are introduced. These measures are Distributed Program Reliability (DPR) and Distributed System Reliability (DSR). A simple and efficient algorithm, SYREL, is developed to evaluate the reliability between two computing centers. This algorithm incorporates conditional probability, set theory, and Boolean algebra in a distinct approach to achieve fast execution times and obtain compact expressions. An elegant and unified approach based on graph-theoretic techniques is used in developing algorithms to evaluate DPR and DSR measures. It performs a breadth-first search on the graph representing a given distributed system to enumerate all the subgraphs that guarantee the proper accessibility for executing the given tasks(s). These subgraphs are then used to evaluate the desired reliabilities. Several optimization algorithms are developed for designing reliable systems under a cost constraint.

  1. 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).

  2. 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.

  3. 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.

  4. On the design of distributed air quality monitoring systems

    NASA Astrophysics Data System (ADS)

    Velasco, Alejandro; Ferrero, Renato; Gandino, Filippo; Montrucchio, Bartolomeo; Rebaudengo, Maurizio

    2015-12-01

    Nowadays, the air quality is considered a key point, and its monitoring is not only suggested but it is even required in many countries. Since traditional standard monitors for air quality are very expensive, the use of a low-cost distributed network of sensors represents a valid complementary approach. This paper discusses the benefits of a distributed approach and analyzes the main elements that should be taken into account during the design of a distributed system for the air quality monitoring. This paper aims at representing a valuable aid for researchers and practitioners interested in the topic.

  5. 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.

  6. Application of geographic information system in distribution power network automation

    NASA Astrophysics Data System (ADS)

    Wei, Xianmin

    2011-02-01

    Geographic information system (GIS) is the computer system in support of computer software with collection, storage, management, retrieval and comprehensive analysis of a variety of geospatial information, with various forms output data and graphics products. This paper introduced GIS data organization and its main applications in distribution power network automation, including both offline and online, and proposed component-based system development model and the need to establish WEBGIS and reliability.

  7. 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.

  8. Development of optical fiber frequency and time distribution systems

    NASA Technical Reports Server (NTRS)

    Lutes, G.

    1982-01-01

    The development of ultra stable optical fiber distribution systems for the dissemination of frequency and timing references is reported. The ultimate design goals for these systems are a frequency stability of 10 to the -17 power for tau or = 100 sec and time stability of + or - 0.1 ns for 1 year and operation over distances or = 30 km. A prototype system is reviewed and progress is discussed.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. A TWACS system alarm function for distribution automation

    SciTech Connect

    Mak, S.T.; Radford, D. )

    1994-04-01

    A new application designated as the System Alarm Function'' is made possible by using the Unsolicited Inbound'' capability recently developed for the Two Way Automatic Communication System (TWACS) System-10, which is already used by several electric utilities in the USA for demand side management, remote metering and distribution automation is reviewed here. The UNSOLICITED INBOUND'' algorithm development, the operational issues that are pertinent to the understanding of collisions between multiple alarms and the effects on the alarm response time'' are discussed in detail. This master-to-master relationship between remote transponders in the distribution network and the central control computer opens the door to multiple functional capabilities in the area of distribution automation and remote monitoring.

  14. 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.

  15. 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.

  16. 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.

  17. LEDA RF distribution system design and component test results

    SciTech Connect

    Roybal, W.T.; Rees, D.E.; Borchert, H.L.; McCarthy, M.; Toole, L.

    1998-12-31

    The 350 MHz and 700 MHz RF distribution systems for the Low Energy Demonstration Accelerator (LEDA) have been designed and are currently being installed at Los Alamos National Laboratory. Since 350 MHz is a familiar frequency used at other accelerator facilities, most of the major high-power components were available. The 700 MHz, 1.0 MW, CW RF delivery system designed for LEDA is a new development. Therefore, high-power circulators, waterloads, phase shifters, switches, and harmonic filters had to be designed and built for this applications. The final Accelerator Production of Tritium (APT) RF distribution systems design will be based on much of the same technology as the LEDA systems and will have many of the RF components tested for LEDA incorporated into the design. Low power and high-power tests performed on various components of these LEDA systems and their results are presented here.

  18. 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.

  19. Evolution of the UCSF Distributed Hospital Information System

    PubMed Central

    Shafarman, Mark; Mapp, Tom; Yip, Rod

    1988-01-01

    The scope of this paper is the continued development of the local area network for application level data exchange in a distributed hospital data network. The need for a modular distributed hospital information system has been well articulated in the past [1]. UCSF Medical Center has been a seminal development center for the linking of separate clinical and administrative systems via a local area network. We discuss the successful project to replace the original prototypical fiber optic LAN [2], the improvements in LAN functionality, and future plans and options.

  20. 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.

  1. Distributed Self-Organizing Intelligent Control For Dendritic Robotic Systems

    NASA Astrophysics Data System (ADS)

    Chen, Alexander Y. K.

    1990-02-01

    A new control methodology is presented to effectively operate a robotic system with redundant degrees of freedom. The utilized Decomposed Optimization Technique (DOT) is part of the AISP (An Intelligent Spatial Planner) development. DOT considers the robotic system as several connected subsystems with locally distributed intelligence. Each subsystem has certain degrees of freedom to pursue local optimum state. The resulting parallel distributed processing architecture presents a flexible structure to accommodate sophisticated manipulators with higher level of difficulty. The employed robot dynamics model for each subsystem is generically simple such that the corresponded read-time control scheme can incorporate self-correction mechanism in parameter identification.

  2. Event-triggered output feedback control for distributed networked systems.

    PubMed

    Mahmoud, Magdi S; Sabih, Muhammad; Elshafei, Moustafa

    2016-01-01

    This paper addresses the problem of output-feedback communication and control with event-triggered framework in the context of distributed networked control systems. The design problem of the event-triggered output-feedback control is proposed as a linear matrix inequality (LMI) feasibility problem. The scheme is developed for the distributed system where only partial states are available. In this scheme, a subsystem uses local observers and share its information to its neighbors only when the subsystem's local error exceeds a specified threshold. The developed method is illustrated by using a coupled cart example from the literature. PMID:26708304

  3. 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.

  4. 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

  5. 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.

  6. Development of distribution system reliability and risk analysis models

    NASA Astrophysics Data System (ADS)

    Northcote-Green, J. E. D.; Vismor, T. D.; Brooks, C. L.

    1981-08-01

    The overall objectives of a research project were to: determine distribution reliability assessment methods currently used by the industry; develop a general outage reporting scheme suitable for a wide variety of distributing utilities (reliability model); develop a model for predicting the reliability of future system configurations (risk model); and compile a handbook of reliability assessment methods designed specifically for use by the practicing distribution engineer. Emphasis was placed on compiling and organizing reliability assessment techniques presently used by the industry. The project examined reliability evaluation from two perspectives: historical and predictive assessment. Two reliability assessment models, HISRAM - the historical reliability assessment model and PRAM - the predictive reliability assessment model were developed. Each model was tested in a utility environment by the Duquesne Light Company and the Public Service Electric and Gas Company of New Jersey. A survey of 56 diverse utilities served as a basis for examining current distribution reliability assessment practices in the electric power industry.

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Fiber optic distribution system for wideband, high performance video

    NASA Astrophysics Data System (ADS)

    Kline, A. R.

    A wideband fiber-optic video distribution system with a bandwidth exceeding 20 MHz has been developed for the NASA Space Station Freedom. The system uses FM modulation and light emitting diodes in combination with lightweight and rugged fiber-optic cables and digital switching elements to provide lightweight, reliable, high-performance video signal distribution over the full extent of the Space Station. The author addresses the Space Station requirements, including environmental constraints, which led to the selected system architecture and choice of components. The design of the modulators and demodulators, optical transmitters and receivers, fiber-optic cable, and the video switches is discussed. Also presented is a description of how the technology can be applied to those military needs which would benefit from the performance, reliability, and EMI/TEMPEST features of the system.

  17. 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.

  18. 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.

  19. 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).

  20. 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).

  1. Interface between astrophysical datasets and distributed database management systems (DAVID)

    NASA Technical Reports Server (NTRS)

    Iyengar, S. S.

    1988-01-01

    This is a status report on the progress of the DAVID (Distributed Access View Integrated Database Management System) project being carried out at Louisiana State University, Baton Rouge, Louisiana. The objective is to implement an interface between Astrophysical datasets and DAVID. Discussed are design details and implementation specifics between DAVID and astrophysical datasets.

  2. 49 CFR 192.721 - Distribution systems: Patrolling.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Distribution systems: Patrolling. 192.721 Section 192.721 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.721...

  3. CORROSION AND CALCIUM CARBONATE SATURATION INDEX IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Corrosion in water distribution systems was studied to gain a better understanding of the processes and to develop control strategies. Equations and calculation methods for determining the pH(sub s) were developed using a chemical model with and without ionic speciation. Several ...

  4. URBAN DRINKING WATER DISTRIBUTION SYSTEMS: A U.S. PERSPECTIVE

    EPA Science Inventory

    This paper will examine several case studies that illustrate the critical role drinking water treatment and distribution systems play in protecting public health. It will also present a case study that documents the dramatic impact that the regulations promulgated under the Safe...

  5. Cometabolism of Monochloramine by Distribution System Relevant Mixed Culture Nitrifiers

    EPA Science Inventory

    Monochloramine (NH2Cl) is increasingly used as a residual disinfectant. A major problem related to NH2Cl is nitrification in distribution systems, leading to rapid NH2Cl residual loss. Ammonia-oxidizing bacteria (AOB), which oxidize ammonia (NH3) to nitrite, can cometabolize chem...

  6. MONOCHLORAMINE DECAY IN MODEL AND DISTRIBUTION SYSTEM WATER. (R826832)

    EPA Science Inventory

    Abstract

    Chloramines have long been used to provide a disinfecting residual in distribution systems where it is difficult to maintain a free chlorine residual or where disinfection by-product (DBP) formation is of concern. While chloramines are generally considered les...

  7. WATER QUALITY EFFECTS RELATED TO BLENDING WATERS IN DISTRIBUTION SYSTEMS

    EPA Science Inventory

    This study was conducted to evaluate the effects of blending two or more waters of different quality and to relate their composition to the corrosive effects and calcium carbonate deposition tendency of the water on distribution systems. The EPA mobile water quality monitoring la...

  8. Towards PCC for Concurrent and Distributed Systems (Work in Progress)

    NASA Technical Reports Server (NTRS)

    Henriksen, Anders S.; Filinski, Andrzej

    2009-01-01

    We outline some conceptual challenges in extending the PCC paradigm to a concurrent and distributed setting, and sketch a generalized notion of module correctness based on viewing communication contracts as economic games. The model supports compositional reasoning about modular systems and is meant to apply not only to certification of executable code, but also of organizational workflows.

  9. Historic drawing. Oxygen Distribution Piping System, 1944. Photographic copy of ...

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

    Historic drawing. Oxygen Distribution Piping System, 1944. Photographic copy of original. Boston National Historical Park. Charlestown Navy Yard. BOSTS 13520, #631-1 - Charlestown Navy Yard, Oxygen Plant, Midway along northern boundary of Charlestown Navy Yard, on Little Mystic Channel, near junction of Eighteenth Street & Fourth Avenue, Boston, Suffolk County, MA

  10. ANIMATION AND VISUALIZATION OF WATER QUALITY IN DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Water may undergo a number of changes in the distribution system, making the quality of the water at the customer's tap different from the quality of the water that leaves the treatment plant. Such changes in quality may be caused by chemical or biological variations or by a loss...

  11. EFFECT OF THE DISTRIBUTION SYSTEM ON DRINKING WATER QUALITY

    EPA Science Inventory

    The SDWA and its amendments has focused interest on the factors that cause the deterioration of water between the treatment plant and the consumer. The distribution system itself can contribute to this deterioration. Numerous examples of waterborne outbreaks have demonstrated the...

  12. Monitoring Design for Source Identification in Water Distribution Systems

    EPA Science Inventory

    The design of sensor networks for the purpose of monitoring for contaminants in water distribution systems is currently an active area of research. Much of the effort has been directed at the contamination detection problem and the expression of public health protection objective...

  13. Cometabolism of Monochloramine by Nitrosomonas europaea under Distribution System Conditions

    EPA Science Inventory

    Batch kinetic experiments were carried out with a pure culture of N. europaea to characterize the kinetics of NH2Cl cometabolism. Nitrite, nitrate, NH2Cl, ammonia and pH were measured. The experiments were performed at a variety of conditions relevant to distribution system nitri...

  14. Online Toxicity Monitors (OTM) for Distribution System Water Quality Monitoring

    EPA Science Inventory

    Drinking water distribution systems in the U.S. are vulnerable to episodic contamination events (both unintentional and intentional). The U.S. Environmental Protection Agency (EPA) is conducting research to investigate the use of broad-spectrum online toxicity monitors (OTMs) in ...

  15. WATER DISTRIBUTION SYSTEM ANALYSIS: FIELD STUDIES, MODELING AND MANAGEMENT

    EPA Science Inventory

    The user‘s guide entitled “Water Distribution System Analysis: Field Studies, Modeling and Management” is a reference guide for water utilities and an extensive summarization of information designed to provide drinking water utility personnel (and related consultants and research...

  16. 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 Section 192.723 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE...

  17. UNSOLVED PROBLEMS WITH CORROSION AND DISTRIBUTION SYSTEM INORGANICS

    EPA Science Inventory

    This presentation provides an overview of new research results and remaining research needs with respect to both corrosion control issues (lead, copper, iron) and to issues of inorganic contaminants that can form or accumulate in distribution system water, pipe scales and distrib...

  18. Particulate Arsenic Release in a Drinking Water Distribution System

    EPA Science Inventory

    Trace contaminants, such as arsenic, have been shown to accumulate in solids found in drinking water distribution systems. The obvious concern is that the contaminants in these solids could be released back into the water resulting in elevated levels in a consumer’s tap water. Th...

  19. DRINKING WATER DISTRIBUTION SYSTEM RELIABILITY: A CASE STUDY

    EPA Science Inventory

    The purpose of the study was to present a tool useful to water utilities that not only could analyze historical distribution system reliability data, but also provide a flexible and expandable mechanism for record-keeping enabling overall management of water work's facilities and...

  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...

  1. Security proof for quantum key distribution using qudit systems

    SciTech Connect

    Sheridan, Lana; Scarani, Valerio

    2010-09-15

    We provide security bounds against coherent attacks for two families of quantum key distribution protocols that use d-dimensional quantum systems. In the asymptotic regime, both the secret key rate for fixed noise and the robustness to noise increase with d. The finite key corrections are found to be almost insensitive to d < or approx. 20.

  2. Resistance of Legionella to disinfection in hot water distribution systems.

    PubMed

    Saby, S; Vidal, A; Suty, H

    2005-01-01

    The efficiency of various disinfection treatments against Legionella was tested on a hot water distribution system (HWDS) pilot unit. The results demonstrated clearly that most Legionella in the networks were fixed in the biofilm at the surface of the pipe (more than 98% for each loop). Chemical treatments (continuous chlorination, hyperchlorination, hydrogen peroxide and peracetic acid mixing) commonly used for the eradication of Legionella in hot water distribution networks appeared to be inadequate for eradicating the bacteria in the biofilm. Unfortunately, the biofilm contained most of the pathogens in an HWDS whereas legislation is only restricted to the Legionella concentration in the water phase. Thermal treatment appeared to be efficient to disinfect most of the biofilm but seemed to promote the biofilm re-growth as well. It was then concluded that the best solution to prevent Legionella contamination in hot water distribution systems would be to have perfect control of the temperature in the networks (temperature > 55 degrees C at all points). Nevertheless, in many cases it is difficult to have such control, so during the time necessary to modify networks, the best solution to control Legionella proliferation appears to be to apply a treatment shock (thermal or chlorination as a function of pipe characteristics). These treatments must be followed by a continuous chlorination that is totally controlled and equipped with alarm systems. This study demonstrates that biofilm sampling devices must be installed in hot water distribution systems to anticipate Legionella contamination and correctly determine the efficiency of the treatments. PMID:16312947

  3. 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.

  4. Automated Energy Distribution and Reliability System Status Report

    SciTech Connect

    Buche, D. L.; Perry, S.

    2007-10-01

    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.

  5. 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.

  6. Metagenomic Analysis of Water Distribution System Bacterial Communities

    EPA Science Inventory

    The microbial quality of drinking water is assessed using culture-based methods that are highly selective and that tend to underestimate the densities and diversity of microbial populations inhabiting distribution systems. In order to better understand the effect of different dis...

  7. 43 CFR 418.27 - Distribution system operation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Distribution system operation. 418.27 Section 418.27 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OPERATING CRITERIA AND PROCEDURES FOR THE NEWLANDS RECLAMATION PROJECT, NEVADA Operations and Management § 418.27...

  8. Distributed parallel computing in stochastic modeling of groundwater systems.

    PubMed

    Dong, Yanhui; Li, Guomin; Xu, Haizhen

    2013-03-01

    Stochastic modeling is a rapidly evolving, popular approach to the study of the uncertainty and heterogeneity of groundwater systems. However, the use of Monte Carlo-type simulations to solve practical groundwater problems often encounters computational bottlenecks that hinder the acquisition of meaningful results. To improve the computational efficiency, a system that combines stochastic model generation with MODFLOW-related programs and distributed parallel processing is investigated. The distributed computing framework, called the Java Parallel Processing Framework, is integrated into the system to allow the batch processing of stochastic models in distributed and parallel systems. As an example, the system is applied to the stochastic delineation of well capture zones in the Pinggu Basin in Beijing. Through the use of 50 processing threads on a cluster with 10 multicore nodes, the execution times of 500 realizations are reduced to 3% compared with those of a serial execution. Through this application, the system demonstrates its potential in solving difficult computational problems in practical stochastic modeling. PMID:22823593

  9. Cloud-based distributed control of unmanned systems

    NASA Astrophysics Data System (ADS)

    Nguyen, Kim B.; Powell, Darren N.; Yetman, Charles; August, Michael; Alderson, Susan L.; Raney, Christopher J.

    2015-05-01

    Enabling warfighters to efficiently and safely execute dangerous missions, unmanned systems have been an increasingly valuable component in modern warfare. The evolving use of unmanned systems leads to vast amounts of data collected from sensors placed on the remote vehicles. As a result, many command and control (C2) systems have been developed to provide the necessary tools to perform one of the following functions: controlling the unmanned vehicle or analyzing and processing the sensory data from unmanned vehicles. These C2 systems are often disparate from one another, limiting the ability to optimally distribute data among different users. The Space and Naval Warfare Systems Center Pacific (SSC Pacific) seeks to address this technology gap through the UxV to the Cloud via Widgets project. The overarching intent of this three year effort is to provide three major capabilities: 1) unmanned vehicle control using an open service oriented architecture; 2) data distribution utilizing cloud technologies; 3) a collection of web-based tools enabling analysts to better view and process data. This paper focuses on how the UxV to the Cloud via Widgets system is designed and implemented by leveraging the following technologies: Data Distribution Service (DDS), Accumulo, Hadoop, and Ozone Widget Framework (OWF).

  10. Commercial thermal distribution systems, Final report for CIEE/CEC

    SciTech Connect

    Xu, Tengfang; Bechu, Olivier; Carrie, Remi; Dickerhoff, Darryl; Fisk, William; Franconi, Ellen; Kristiansen, Oyvind; Levinson, Ronnen; McWilliams, Jennifer; Wang, Duo; Modera, Mark; Webster, Tom; Ring, Erik; Zhang, Qiang; Huizenga, Charlie; Bauman, Fred; Arens, Ed

    1999-12-01

    According to the California Energy Commission (CEC 1998a), California commercial buildings account for 35% of statewide electricity consumption, and 16% of statewide gas consumption. Space conditioning accounts for roughly 16,000 GWh of electricity and 800 million therms of natural gas annually, and the vast majority of this space conditioning energy passes through thermal distribution systems in these buildings. In addition, 8600 GWh per year is consumed by fans and pumps in commercial buildings, most of which is used to move the thermal energy through these systems. Research work at Lawrence Berkeley National Laboratory (LBNL) has been ongoing over the past five years to investigate the energy efficiency of these thermal distribution systems, and to explore possibilities for improving that energy efficiency. Based upon that work, annual savings estimates of 1 kWh/ft{sup 2} for light commercial buildings, and 1-2 kWh/ft{sup 2} in large commercial buildings have been developed for the particular aspects of thermal distribution system performance being addressed by this project. Those savings estimates, combined with a distribution of the building stock based upon an extensive stock characterization study (Modera et al. 1999a), and technical penetration estimates, translate into statewide saving potentials of 2000 GWh/year and 75 million thermal/year, as well as an electricity peak reduction potential of 0.7 GW. The overall goal of this research program is to provide new technology and application knowledge that will allow the design, construction, and energy services industries to reduce the energy waste associated with thermal distribution systems in California commercial buildings. The specific goals of the LBNL efforts over the past year were: (1) to advance the state of knowledge about system performance and energy losses in commercial-building thermal distribution systems; (2) to evaluate the potential of reducing thermal losses through duct sealing, duct

  11. Job Admission and Resource Allocation in Distributed Streaming Systems

    NASA Astrophysics Data System (ADS)

    Wolf, Joel; Bansal, Nikhil; Hildrum, Kirsten; Parekh, Sujay; Rajan, Deepak; Wagle, Rohit; Wu, Kun-Lung

    This paper describes a new and novel scheme for job admission and resource allocation employed by the SODA scheduler in System S. Capable of processing enormous quantities of streaming data, System S is a large-scale, distributed stream processing system designed to handle complex applications. The problem of scheduling in distributed, stream-based systems is quite unlike that in more traditional systems. And the requirements for System S, in particular, are more stringent than one might expect even in a “standard” stream-based design. For example, in System S, the offered load is expected to vastly exceed system capacity. So a careful job admission scheme is essential. The jobs in System S are essentially directed graphs, with software “processing elements” (PEs) as vertices and data streams as edges connecting the PEs. The jobs themselves are often heavily interconnected. Thus resource allocation of individual PEs must be done carefully in order to balance the flow. We describe the design of the SODA scheduler, with particular emphasis on the component, known as macroQ, which performs the job admission and resource allocation tasks. We demonstrate by experiments the natural trade-offs between job admission and resource allocation.

  12. NASA Langley Research Center's distributed mass storage system

    NASA Technical Reports Server (NTRS)

    Pao, Juliet Z.; Humes, D. Creig

    1993-01-01

    There is a trend in institutions with high performance computing and data management requirements to explore mass storage systems with peripherals directly attached to a high speed network. The Distributed Mass Storage System (DMSS) Project at NASA LaRC is building such a system and expects to put it into production use by the end of 1993. This paper presents the design of the DMSS, some experiences in its development and use, and a performance analysis of its capabilities. The special features of this system are: (1) workstation class file servers running UniTree software; (2) third party I/O; (3) HIPPI network; (4) HIPPI/IPI3 disk array systems; (5) Storage Technology Corporation (STK) ACS 4400 automatic cartridge system; (6) CRAY Research Incorporated (CRI) CRAY Y-MP and CRAY-2 clients; (7) file server redundancy provision; and (8) a transition mechanism from the existent mass storage system to the DMSS.

  13. Dynamics of Biofilm Regrowth in Drinking Water Distribution Systems

    PubMed Central

    Husband, S.; Loza, V.; Boxall, J.

    2016-01-01

    ABSTRACT The majority of biomass within water distribution systems is in the form of attached biofilm. This is known to be central to drinking water quality degradation following treatment, yet little understanding of the dynamics of these highly heterogeneous communities exists. This paper presents original information on such dynamics, with findings demonstrating patterns of material accumulation, seasonality, and influential factors. Rigorous flushing operations repeated over a 1-year period on an operational chlorinated system in the United Kingdom are presented here. Intensive monitoring and sampling were undertaken, including time-series turbidity and detailed microbial analysis using 16S rRNA Illumina MiSeq sequencing. The results show that bacterial dynamics were influenced by differences in the supplied water and by the material remaining attached to the pipe wall following flushing. Turbidity, metals, and phosphate were the main factors correlated with the distribution of bacteria in the samples. Coupled with the lack of inhibition of biofilm development due to residual chlorine, this suggests that limiting inorganic nutrients, rather than organic carbon, might be a viable component in treatment strategies to manage biofilms. The research also showed that repeat flushing exerted beneficial selective pressure, giving another reason for flushing being a viable advantageous biofilm management option. This work advances our understanding of microbiological processes in drinking water distribution systems and helps inform strategies to optimize asset performance. IMPORTANCE This research provides novel information regarding the dynamics of biofilm formation in real drinking water distribution systems made of different materials. This new knowledge on microbiological process in water supply systems can be used to optimize the performance of the distribution network and to guarantee safe and good-quality drinking water to consumers. PMID:27208119

  14. Adaptive, Distributed Control of Constrained Multi-Agent Systems

    NASA Technical Reports Server (NTRS)

    Bieniawski, Stefan; Wolpert, David H.

    2004-01-01

    Product Distribution (PO) theory was recently developed as a broad framework for analyzing and optimizing distributed systems. Here we demonstrate its use for adaptive distributed control of Multi-Agent Systems (MASS), i.e., for distributed stochastic optimization using MAS s. First we review one motivation of PD theory, as the information-theoretic extension of conventional full-rationality game theory to the case of bounded rational agents. In this extension the equilibrium of the game is the optimizer of a Lagrangian of the (Probability dist&&on on the joint state of the agents. When the game in question is a team game with constraints, that equilibrium optimizes the expected value of the team game utility, subject to those constraints. One common way to find that equilibrium is to have each agent run a Reinforcement Learning (E) algorithm. PD theory reveals this to be a particular type of search algorithm for minimizing the Lagrangian. Typically that algorithm i s quite inefficient. A more principled alternative is to use a variant of Newton's method to minimize the Lagrangian. Here we compare this alternative to RL-based search in three sets of computer experiments. These are the N Queen s problem and bin-packing problem from the optimization literature, and the Bar problem from the distributed RL literature. Our results confirm that the PD-theory-based approach outperforms the RL-based scheme in all three domains.

  15. Energy management and control of active distribution systems

    NASA Astrophysics Data System (ADS)

    Shariatzadeh, Farshid

    Advancements in the communication, control, computation and information technologies have driven the transition to the next generation active power distribution systems. Novel control techniques and management strategies are required to achieve the efficient, economic and reliable grid. The focus of this work is energy management and control of active distribution systems (ADS) with integrated renewable energy sources (RESs) and demand response (DR). Here, ADS mean automated distribution system with remotely operated controllers and distributed energy resources (DERs). DER as active part of the next generation future distribution system includes: distributed generations (DGs), RESs, energy storage system (ESS), plug-in hybrid electric vehicles (PHEV) and DR. Integration of DR and RESs into ADS is critical to realize the vision of sustainability. The objective of this dissertation is the development of management architecture to control and operate ADS in the presence of DR and RES. One of the most challenging issues for operating ADS is the inherent uncertainty of DR and RES as well as conflicting objective of DER and electric utilities. ADS can consist of different layers such as system layer and building layer and coordination between these layers is essential. In order to address these challenges, multi-layer energy management and control architecture is proposed with robust algorithms in this work. First layer of proposed multi-layer architecture have been implemented at the system layer. Developed AC optimal power flow (AC-OPF) generates fair price for all DR and non-DR loads which is used as a control signal for second layer. Second layer controls DR load at buildings using a developed look-ahead robust controller. Load aggregator collects information from all buildings and send aggregated load to the system optimizer. Due to the different time scale at these two management layers, time coordination scheme is developed. Robust and deterministic controllers

  16. Guest Editor's Introduction: Special section on dependable distributed systems

    NASA Astrophysics Data System (ADS)

    Fetzer, Christof

    1999-09-01

    We rely more and more on computers. For example, the Internet reshapes the way we do business. A `computer outage' can cost a company a substantial amount of money. Not only with respect to the business lost during an outage, but also with respect to the negative publicity the company receives. This is especially true for Internet companies. After recent computer outages of Internet companies, we have seen a drastic fall of the shares of the affected companies. There are multiple causes for computer outages. Although computer hardware becomes more reliable, hardware related outages remain an important issue. For example, some of the recent computer outages of companies were caused by failed memory and system boards, and even by crashed disks - a failure type which can easily be masked using disk mirroring. Transient hardware failures might also look like software failures and, hence, might be incorrectly classified as such. However, many outages are software related. Faulty system software, middleware, and application software can crash a system. Dependable computing systems are systems we can rely on. Dependable systems are, by definition, reliable, available, safe and secure [3]. This special section focuses on issues related to dependable distributed systems. Distributed systems have the potential to be more dependable than a single computer because the probability that all computers in a distributed system fail is smaller than the probability that a single computer fails. However, if a distributed system is not built well, it is potentially less dependable than a single computer since the probability that at least one computer in a distributed system fails is higher than the probability that one computer fails. For example, if the crash of any computer in a distributed system can bring the complete system to a halt, the system is less dependable than a single-computer system. Building dependable distributed systems is an extremely difficult task. There is no

  17. Research into a distributed fault diagnosis system and its application

    NASA Astrophysics Data System (ADS)

    Qian, Suxiang; Jiao, Weidong; Lou, Yongjian; Shen, Xiaomei

    2005-12-01

    CORBA (Common Object Request Broker Architecture) is a solution to distributed computing methods over heterogeneity systems, which establishes a communication protocol between distributed objects. It takes great emphasis on realizing the interoperation between distributed objects. However, only after developing some application approaches and some practical technology in monitoring and diagnosis, can the customers share the monitoring and diagnosis information, so that the purpose of realizing remote multi-expert cooperation diagnosis online can be achieved. This paper aims at building an open fault monitoring and diagnosis platform combining CORBA, Web and agent. Heterogeneity diagnosis object interoperate in independent thread through the CORBA (soft-bus), realizing sharing resource and multi-expert cooperation diagnosis online, solving the disadvantage such as lack of diagnosis knowledge, oneness of diagnosis technique and imperfectness of analysis function, so that more complicated and further diagnosis can be carried on. Take high-speed centrifugal air compressor set for example, we demonstrate a distributed diagnosis based on CORBA. It proves that we can find out more efficient approaches to settle the problems such as real-time monitoring and diagnosis on the net and the break-up of complicated tasks, inosculating CORBA, Web technique and agent frame model to carry on complemental research. In this system, Multi-diagnosis Intelligent Agent helps improve diagnosis efficiency. Besides, this system offers an open circumstances, which is easy for the diagnosis objects to upgrade and for new diagnosis server objects to join in.

  18. Performance Monitoring of Residential Hot Water Distribution Systems

    SciTech Connect

    Liao, Anna; Lanzisera, Steven; Lutz, Jim; Fitting, Christian; Kloss, Margarita; Stiles, Christopher

    2014-08-11

    Current water distribution systems are designed such that users need to run the water for some time to achieve the desired temperature, wasting energy and water in the process. We developed a wireless sensor network for large-scale, long time-series monitoring of residential water end use. Our system consists of flow meters connected to wireless motes transmitting data to a central manager mote, which in turn posts data to our server via the internet. This project also demonstrates a reliable and flexible data collection system that could be configured for various other forms of end use metering in buildings. The purpose of this study was to determine water and energy use and waste in hot water distribution systems in California residences. We installed meters at every end use point and the water heater in 20 homes and collected 1s flow and temperature data over an 8 month period. For a typical shower and dishwasher events, approximately half the energy is wasted. This relatively low efficiency highlights the importance of further examining the energy and water waste in hot water distribution systems.

  19. Distributed proximity sensor system having embedded light emitters and detectors

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1990-01-01

    A distributed proximity sensor system is provided with multiple photosensitive devices and light emitters embedded on the surface of a robot hand or other moving member in a geometric pattern. By distributing sensors and emitters capable of detecting distances and angles to points on the surface of an object from known points in the geometric pattern, information is obtained for achieving noncontacting shape and distance perception, i.e., for automatic determination of the object's shape, direction and distance, as well as the orientation of the object relative to the robot hand or other moving member.

  20. Modeling Uncertainties in Power System by Generalized Lambda Distribution

    NASA Astrophysics Data System (ADS)

    Xiao, Qing

    2014-06-01

    This paper employs the generalized lambda distribution (GLD) to model random variables with various probability distributions in power system. In the context of the probability weighted moment (PWM), an optimization-free method is developed to assess the parameters of GLD. By equating the first four PWMs of GLD with those of the target random variable, a polynomial equation with one unknown is derived to solve for the parameters of GLD. When employing GLD to model correlated multivariate random variables, a method of accommodating the dependency is put forward. Finally, three examples are worked to demonstrate the proposed method.

  1. Radar data processing using a distributed computational system

    NASA Astrophysics Data System (ADS)

    Mota, Gilberto F.

    1992-06-01

    This research specifies and validates a new concurrent decomposition scheme, called Confined Space Search Decomposition (CSSD), to exploit parallelism of Radar Data Processing algorithms using a Distributed Computational System. To formalize the specification, we propose and apply an object-oriented methodology called Decomposition Cost Evaluation Model (DCEM). To reduce the penalties of load imbalance, we propose a distributed dynamic load balance heuristic called Object Reincarnation (OR). To validate the research, we first compare our decomposition with an identified alternative using the proposed DCEM model and then develop a theoretical prediction of selected parameters. We also develop a simulation to check the Object Reincarnation Concept.

  2. Fault Location Methods for Ungrounded Distribution Systems Using Local Measurements

    NASA Astrophysics Data System (ADS)

    Xiu, Wanjing; Liao, Yuan

    2013-08-01

    This article presents novel fault location algorithms for ungrounded distribution systems. The proposed methods are capable of locating faults by using obtained voltage and current measurements at the local substation. Two types of fault location algorithms, using line to neutral and line to line measurements, are presented. The network structure and parameters are assumed to be known. The network structure needs to be updated based on information obtained from utility telemetry system. With the help of bus impedance matrix, local voltage changes due to the fault can be expressed as a function of fault currents. Since the bus impedance matrix contains information about fault location, superimposed voltages at local substation can be expressed as a function of fault location, through which fault location can be solved. Simulation studies have been carried out based on a sample distribution power system. From the evaluation study, it is evinced that very accurate fault location estimates are obtained from both types of methods.

  3. The Fermilab CMTF cryogenic distribution remote control system

    NASA Astrophysics Data System (ADS)

    Pei, L.; Theilacker, J.; Klebaner, A.; Martinez, A.; Bossert, R.

    2014-01-01

    The Cryomodule Test Facility (CMTF) is able to provide the necessary test bed for measuring the performance of Superconducting Radio Frequency (SRF) cavities in a cryomodule (CM). The CMTF have seven 300 KW screw compressors, two liquid helium refrigerators, and two Cryomodule Test Stands (CMTS). CMTS1 is designed for 1.3 GHz cryomodule operating in a pulsed mode (PM) and CMTS2 is for cryomodule operating in Half-Wave (HW) and Continuous Wave (CW) mode. Based on the design requirement, each subsystem has to be far away from each other and be placed in distant locations. Therefore choosing Siemens Process Control System 7-400, DL205 PLC, Synoptic and Fermilab ACNET are the ideal choices for CMTF cryogenic distribution real-time remote control system. This paper presents a method which has been successfully used by many Fermilab distribution cryogenic real-time remote control systems.

  4. Foundational Report Series: Advanced Distribution Management Systems for Grid Modernization

    SciTech Connect

    Wang, Jianhui

    2015-09-01

    This report describes the application functions for distribution management systems (DMS). The application functions are those surveyed by the IEEE Power and Energy Society’s Task Force on Distribution Management Systems. The description of each DMS application includes functional requirements and the key features and characteristics in current and future deployments, as well as a summary of the major benefits provided by each function to stakeholders — from customers to shareholders. Due consideration is paid to the fact that the realizable benefits of each function may differ by type of utility, whether investor-owned, cooperative, or municipal. This report is sufficient to define the functional requirements of each application for system procurement (request-for-proposal [RFP]) purposes and for developing preliminary high-level use cases for those functions. However, it should not be considered a design document that will enable a vendor or software developer to design and build actual DMS applications.

  5. Galerkin approximation for inverse problems for nonautonomous nonlinear distributed systems

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Reich, Simeon; Rosen, I. G.

    1988-01-01

    An abstract framework and convergence theory is developed for Galerkin approximation for inverse problems involving the identification of nonautonomous nonlinear distributed parameter systems. A set of relatively easily verified conditions is provided which are sufficient to guarantee the existence of optimal solutions and their approximation by a sequence of solutions to a sequence of approximating finite dimensional identification problems. The approach is based on the theory of monotone operators in Banach spaces and is applicable to a reasonably broad class of nonlinear distributed systems. Operator theoretic and variational techniques are used to establish a fundamental convergence result. An example involving evolution systems with dynamics described by nonstationary quasilinear elliptic operators along with some applications are presented and discussed.

  6. Alert Messaging in the CMS Distributed Workflow System

    NASA Astrophysics Data System (ADS)

    Maxa, Zdenek

    2012-12-01

    WMAgent is the core component of the CMS workload management system. One of the features of this job managing platform is a configurable messaging system aimed at generating, distributing and processing alerts: short messages describing a given alert-worthy information or pathological condition. Apart from the framework's sub-components running within the WMAgent instances, there is a stand-alone application collecting alerts from all WMAgent instances running across the CMS distributed computing environment. The alert framework has a versatile design that allows for receiving alert messages also from other CMS production applications, such as PhEDEx data transfer manager. We present implementation details of the system, including its Python implementation using ZeroMQ, CouchDB message storage and future visions as well as operational experiences. Inter-operation with monitoring platforms such as Dashboard or Lemon is described.

  7. Garbage Collection in a Distributed Object-Oriented System

    NASA Technical Reports Server (NTRS)

    Gupta, Aloke; Fuchs, W. Kent

    1993-01-01

    An algorithm is described in this paper for garbage collection in distributed systems with object sharing across processor boundaries. The algorithm allows local garbage collection at each node in the system to proceed independently of local collection at the other nodes. It requires no global synchronization or knowledge of the global state of the system and exhibits the capability of graceful degradation. The concept of a specialized dump node is proposed to facilitate the collection of inaccessible circular structures. An experimental evaluation of the algorithm is also described. The algorithm is compared with a corresponding scheme that requires global synchronization. The results show that the algorithm works well in distributed processing environments even when the locality of object references is low.

  8. The Fermilab CMTF cryogenic distribution remote control system

    SciTech Connect

    Pei, L.; Theilacker, J.; Klebaner, A.; Martinez, A.; Bossert, R.

    2014-01-29

    The Cryomodule Test Facility (CMTF) is able to provide the necessary test bed for measuring the performance of Superconducting Radio Frequency (SRF) cavities in a cryomodule (CM). The CMTF have seven 300 KW screw compressors, two liquid helium refrigerators, and two Cryomodule Test Stands (CMTS). CMTS1 is designed for 1.3 GHz cryomodule operating in a pulsed mode (PM) and CMTS2 is for cryomodule operating in Half-Wave (HW) and Continuous Wave (CW) mode. Based on the design requirement, each subsystem has to be far away from each other and be placed in distant locations. Therefore choosing Siemens Process Control System 7-400, DL205 PLC, Synoptic and Fermilab ACNET are the ideal choices for CMTF cryogenic distribution real-time remote control system. This paper presents a method which has been successfully used by many Fermilab distribution cryogenic real-time remote control systems.

  9. High-Frequency ac Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.; Mildice, James

    1987-01-01

    Loads managed automatically under cycle-by-cycle control. 440-V rms, 20-kHz ac power system developed. System flexible, versatile, and "transparent" to user equipment, while maintaining high efficiency and low weight. Electrical source, from dc to 2,200-Hz ac converted to 440-V rms, 20-kHz, single-phase ac. Power distributed through low-inductance cables. Output power either dc or variable ac. Energy transferred per cycle reduced by factor of 50. Number of parts reduced by factor of about 5 and power loss reduced by two-thirds. Factors result in increased reliability and reduced costs. Used in any power-distribution system requiring high efficiency, high reliability, low weight, and flexibility to handle variety of sources and loads.

  10. A qualitative study of the retention and release of volatile gases in JSC-1A lunar soil simulant at room temperature under ultrahigh vacuum (UHV) conditions

    NASA Astrophysics Data System (ADS)

    Patrick, Edward L.; Mandt, K. E.; Escobedo, S. M.; Winters, G. S.; Mitchell, J. N.; Teolis, B. D.

    2015-07-01

    We conducted a qualitative study to simulate the flux of volatile gases expected to occur at the lunar surface due to cometary impact or lunar outgassing events. A small sample cell containing 8.8 g of JSC-1A lunar soil simulant in a vacuum system with a base pressure of 1.5 × 10-8 Torr was exposed to various gases using dynamic pressure dosing at room temperature to observe any retention of those gases as a function of the exposure times, temperatures and pressures used. Gases included pure argon, a five-component gas mixture (H2, He, Ne, N2, Ar), a simulated Mars atmospheric mixture (CO2, N2, Ar, CO, O2), and a simulated Titan mixture (N2, CH4). Results at exposure pressures of approximately 1.5 × 10-8 Torr above background showed no observable retention of rare gases, slight retention of molecular gases, but surface retention of the triatomic gas CO2 occurred at room temperature with a time to reach equilibrium of greater than 10 min, which was an unanticipated result. Despite several bakeouts and months under ultrahigh vacuum (UHV) conditions, trace levels of atmospheric gases continued to evolve from the simulant. Mechanical and optical probing of the simulant surface increased this latent gas evolution, particularly for CO2 and CO, with some evidence also for the release of CH4. We assert our results are, by analogy, applicable to protocols and instrumentation needed for conducting analytical chemistry aboard future landed lunar missions.

  11. Regeneration of LOHC dehydrogenation catalysts: In-situ IR spectroscopy on single crystals, model catalysts, and real catalysts from UHV to near ambient pressure

    NASA Astrophysics Data System (ADS)

    Amende, Max; Kaftan, Andre; Bachmann, Philipp; Brehmer, Richard; Preuster, Patrick; Koch, Marcus; Wasserscheid, Peter; Libuda, Jörg

    2016-01-01

    The Liquid Organic Hydrogen Carrier (LOHC) concept offers an efficient route to store hydrogen using organic compounds that are reversibly hydrogenated and dehydrogenated. One important challenge towards application of the LOHC technology at a larger scale is to minimize degradation of Pt-based dehydrogenation catalysts during long-term operation. Herein, we investigate the regeneration of Pt/alumina catalysts poisoned by LOHC degradation. We combine ultrahigh vacuum (UHV) studies on Pt(111), investigations on well-defined Pt/Al2O3 model catalysts, and near-ambient pressure (NAP) measurements on real core-shell Pt/Al2O3 catalyst pellets. The catalysts were purposely poisoned by reaction with the LOHC perhydro-dibenzyltoluene (H18-MSH) and with dicyclohexylmethane (DCHM) as a simpler model compound. We focus on oxidative regeneration under conditions that may be applied in real dehydrogenation reactors. The degree of poisoning and regeneration under oxidative reaction conditions was quantified using CO as a probe molecule and measured by infrared reflection-absorption spectroscopy (IRAS) and diffuse reflectance Fourier transform IR spectroscopy (DRIFTS) for planar model systems and real catalysts, respectively. We find that regeneration strongly depends on the composition of the catalyst surface. While the clean surface of a poisoned Pt(111) single crystal is fully restored upon thermal treatment in oxygen up to 700 K, contaminated Pt/Al2O3 model catalyst and core-shell pellet were only partially restored under the applied reaction conditions. Whereas partial regeneration on facet-like sites on supported catalysts is more facile than on Pt(111), carbonaceous deposits adsorbed at low-coordinated defect sites impede full regeneration of the Pt/Al2O3 catalysts.

  12. Mathematical optimization of matter distribution for a planetary system configuration

    NASA Astrophysics Data System (ADS)

    Morozov, Yegor; Bukhtoyarov, Mikhail

    2016-07-01

    Planetary formation is mostly a random process. When the humanity reaches the point when it can transform planetary systems for the purpose of interstellar life expansion, the optimal distribution of matter in a planetary system will determine its population and expansive potential. Maximization of the planetary system carrying capacity and its potential for the interstellar life expansion depends on planetary sizes, orbits, rotation, chemical composition and other vital parameters. The distribution of planetesimals to achieve maximal carrying capacity of the planets during their life cycle, and maximal potential to inhabit other planetary systems must be calculated comprehensively. Moving much material from one planetary system to another is uneconomic because of the high amounts of energy and time required. Terraforming of the particular planets before the whole planetary system is configured might drastically decrease the potential habitability the whole system. Thus a planetary system is the basic unit for calculations to sustain maximal overall population and expand further. The mathematical model of optimization of matter distribution for a planetary system configuration includes the input observed parameters: the map of material orbiting in the planetary system with specified orbits, masses, sizes, and the chemical compound for each, and the optimized output parameters. The optimized output parameters are sizes, masses, the number of planets, their chemical compound, and masses of the satellites required to make tidal forces. Also the magnetic fields and planetary rotations are crucial, but they will be considered in further versions of this model. The optimization criteria is the maximal carrying capacity plus maximal expansive potential of the planetary system. The maximal carrying capacity means the availability of essential life ingredients on the planetary surface, and the maximal expansive potential means availability of uranium and metals to build

  13. Distributed autonomous systems: resource management, planning, and control algorithms

    NASA Astrophysics Data System (ADS)

    Smith, James F., III; Nguyen, ThanhVu H.

    2005-05-01

    Distributed autonomous systems, i.e., systems that have separated distributed components, each of which, exhibit some degree of autonomy are increasingly providing solutions to naval and other DoD problems. Recently developed control, planning and resource allocation algorithms for two types of distributed autonomous systems will be discussed. The first distributed autonomous system (DAS) to be discussed consists of a collection of unmanned aerial vehicles (UAVs) that are under fuzzy logic control. The UAVs fly and conduct meteorological sampling in a coordinated fashion determined by their fuzzy logic controllers to determine the atmospheric index of refraction. Once in flight no human intervention is required. A fuzzy planning algorithm determines the optimal trajectory, sampling rate and pattern for the UAVs and an interferometer platform while taking into account risk, reliability, priority for sampling in certain regions, fuel limitations, mission cost, and related uncertainties. The real-time fuzzy control algorithm running on each UAV will give the UAV limited autonomy allowing it to change course immediately without consulting with any commander, request other UAVs to help it, alter its sampling pattern and rate when observing interesting phenomena, or to terminate the mission and return to base. The algorithms developed will be compared to a resource manager (RM) developed for another DAS problem related to electronic attack (EA). This RM is based on fuzzy logic and optimized by evolutionary algorithms. It allows a group of dissimilar platforms to use EA resources distributed throughout the group. For both DAS types significant theoretical and simulation results will be presented.

  14. Requirements and overview of the LINCS distributed operating system architecture

    SciTech Connect

    Watson, R.W.

    1984-04-01

    This paper presents an overview of the Livermore Interactive Network Communication System (LINCS) architecture. This section outlines its general requirements and the following sections outline the central features of its design that meet these requirements. LINCS is an integrated operating system and network architecture. To emphasize this integration we refer to LINCS as a network or distributed operating system architecture. A metaphor that may be useful in thinking about LINCS is that it provides a software bus structure that provides a framework for integrating new applications and services. The software bus is defined by a layered set of communication protocols. 25 references.

  15. Control of Groundwater Remediation Process as Distributed Parameter System

    NASA Astrophysics Data System (ADS)

    Mendel, M.; Kovács, T.; Hulkó, G.

    2014-12-01

    Pollution of groundwater requires the implementation of appropriate solutions which can be deployed for several years. The case of local groundwater contamination and its subsequent spread may result in contamination of drinking water sources or other disasters. This publication aims to design and demonstrate control of pumping wells for a model task of groundwater remediation. The task consists of appropriately spaced soil with input parameters, pumping wells and control system. Model of controlled system is made in the program MODFLOW using the finitedifference method as distributed parameter system. Control problem is solved by DPS Blockset for MATLAB & Simulink.

  16. Pulmonary disease management system with distributed wearable sensors.

    PubMed

    Fu, Yongji; Ayyagari, Deepak; Colquitt, Nhedti

    2009-01-01

    A pulmonary disease management system with on-body and near-body sensors is introduced in this presentation. The system is wearable for continuous ambulatory monitoring. Distributed sensor data is transferred through a wireless body area network (BAN) to a central controller for real time analysis. Physiological and environmental parameters are monitored and analyzed using prevailing clinical guidelines for self-management of environmentally-linked pulmonary ailments. The system provides patients with reminders, warnings, and instructions to reduce emergency room and physician visits, and improve clinical outcomes. PMID:19963731

  17. Distributed Online Judge System for Interactive Theorem Provers

    NASA Astrophysics Data System (ADS)

    Mizuno, Takahisa; Nishizaki, Shin-ya

    2014-03-01

    In this paper, we propose a new software design of an online judge system for interactive theorem proving. The distinctive feature of this architecture is that our online judge system is distributed on the network and especially involves volunteer computing. In volunteers' computers, network bots (software robots) are executed and donate computational resources to the central host of the online judge system. Our proposed design improves fault tolerance and security. We gave an implementation to two different styles of interactive theorem prover, Coq and ACL2, and evaluated our proposed architecture. From the experiment on the implementation, we concluded that our architecture is efficient enough to be used practically.

  18. GPR-Based Water Leak Models in Water Distribution Systems

    PubMed Central

    Ayala-Cabrera, David; Herrera, Manuel; Izquierdo, Joaquín; Ocaña-Levario, Silvia J.; Pérez-García, Rafael

    2013-01-01

    This paper addresses the problem of leakage in water distribution systems through the use of ground penetrating radar (GPR) as a nondestructive method. Laboratory tests are performed to extract features of water leakage from the obtained GPR images. Moreover, a test in a real-world urban system under real conditions is performed. Feature extraction is performed by interpreting GPR images with the support of a pre-processing methodology based on an appropriate combination of statistical methods and multi-agent systems. The results of these tests are presented, interpreted, analyzed and discussed in this paper.

  19. Radial distribution of metallicity in the LMC cluster systems

    NASA Technical Reports Server (NTRS)

    Kontizas, M.; Kontizas, E.; Michalitsianos, A. G.

    1993-01-01

    New determinations of the deprojected distances to the galaxy center for 94 star clusters and their metal abundances are used to investigate the variation of metallicity across the two LMC star cluster systems (Kontizas et al. 1990). A systematic radial trend of metallicity is observed in the extended outer cluster system, the outermost clusters being significantly metal poorer than the more central ones, with the exception of six clusters (which might lie out of the plane of the cluster system) out of 77. A radial metallicity gradient has been found, qualitatively comparable to that of the Milky Way for its system of the old disk clusters. If the six clusters are taken into consideration then the outer cluster system is well mixed up to 8 kpc. The spatial distribution of metallicities for the inner LMC cluster system, consisting of very young globulars does not show a systematic radial trend; they are all metal rich.

  20. Quartz microbalance device for transfer into ultrahigh vacuum systems

    SciTech Connect

    Stavale, F.; Achete, C. A.; Niehus, H.

    2008-10-15

    An uncomplicated quartz microbalance device has been developed which is transferable into ultrahigh vacuum (UHV) systems. The device is extremely useful for flux calibration of different kinds of material evaporators. Mounted on a commercial specimen holder, the device allows fast quartz microbalance transfer into the UHV and subsequent positioning exactly to the sample location where subsequent thin film deposition experiments shall be carried out. After backtransfer into an UHV sample stage, the manipulator may be loaded in situ with the specimen suited for the experiment. The microbalance device capability is demonstrated for monolayer and submonolayer vanadium depositions with an achieved calibration sensitivity of less the 0.001 ML coverage.