Sample records for open distributed systems

  1. Resonance Width Distribution for Open Chaotic Quantum Systems

    NASA Astrophysics Data System (ADS)

    Shchedrin, Gavriil

    2012-10-01

    Recent measurements of resonance widths, ?, for low-energy neutron scattering off heavy nuclei claim significant deviations from the standard chi-square 2?1(?), or the Porter-Thomas, distribution. The unstable nucleus is an open quantum system, where the intrinsic dynamics has to be supplemented by the coupling of chaotic internal states through the continuum. We propose a new resonance width distribution based on the random matrix theory for an open quantum system. For a single open channel, the new distribution is P(?)=C2?1(?)?sinh?/? where ?=??/2D and D is the mean energy level spacing. This result naturally recovers the Porter-Thomas distribution for small ? and can be directly applied to a whole range of mesoscopic systems, and is invariant under ?->?-?, where? is the total width. The realistic situation in nuclei is not that of a single neutron channel. Many photon channels are always opened which modifies the width distribution into P(,)=C2?1(?-?)?sinh??/?? with ??=?(?-?)/2D, and the whole distribution is shifted by ?, an average radiation width.

  2. Intelligent mechatronic components: control system engineering using an open distributed architecture

    Microsoft Academic Search

    V. Vyatkin

    2003-01-01

    This paper reports the results of case study on application of open distributed software architecture IEC61499 to the organization of intelligence, embedded to smart mechatronic components. The presented approach targets the issues related to integration and reconfiguration of automation systems, where the software integration plays an important role. Based on the testbed studies, a classification of \\

  3. A distributed database system for sharing geological information using free and open source software

    NASA Astrophysics Data System (ADS)

    Nemoto, T.; Masumoto, S.; Nonogaki, S.; Raghavan, V.

    2013-12-01

    Recently, geological information, such as borehole data and geological maps, and seismic, volcanic or landslide hazard maps are published on the Internet by the national government, local governments, and research institutes in Japan. Most web systems that deliver such geological information consist of a centralized database, which are located and maintained in one location. It is easier to manage the centralized database system because all data resides in a single location. However, if the database breaks, the web service will not be available. In the present study, a distributed database system has been developed to continue delivering geological information even if a database breaks. The distributed database system has an advantage that the system remains available although an individual database is down. All the software used to construct the system is free and open source software. PostgreSQL and pgpool-II are utilized to construct a distributed database. PostgreSQL is a powerful relational database management system. Pgpool-II has a function for management of multiple PostgreSQL servers. OpenLayers is used for the web map clients. Replication and Parallel query modes with pgpool-II are utilized for distribution of a database. It is possible to create a real-time backup on 2 or more PostgreSQL clusters by replication mode. If a database breaks, the backup database will works to continue delivering geological information. Data can be split among multiple servers by using parallel query mode. The rules to send partitioned data to an appropriate cluster are contained in the System Database. If large-scale data is searched, the overall execution time will be reduced. The prototype for sharing 1500 borehole data has been successfully implemented by combination of PostgreSQL and pgpool-II on Linux server. Further development and improvement of the system are necessary to manage and analyze various spatial data in addition to borehole data. This study was supported by KAKENHI (24700096, 25330134; Grant-in-Aid for Scientific Research by Japan Society for Promotion of Science).

  4. The Earth System Grid Federation: An Open Infrastructure for Access to Distributed Geo-Spatial Data

    SciTech Connect

    Cinquini, Luca [Jet Propulsion Laboratory, Pasadena, CA; Crichton, Daniel [Jet Propulsion Laboratory, Pasadena, CA; Miller, Neill [Argonne National Laboratory (ANL); Mattmann, Chris [Jet Propulsion Laboratory, Pasadena, CA; Harney, John F [ORNL; Shipman, Galen M [ORNL; Wang, Feiyi [ORNL; Bell, Gavin [Lawrence Livermore National Laboratory (LLNL); Drach, Bob [Lawrence Livermore National Laboratory (LLNL); Ananthakrishnan, Rachana [Argonne National Laboratory (ANL); Pascoe, Stephen [STFC Rutherford Appleton Laboratory, NCAS/BADC; Kershaw, Philip [STFC Rutherford Appleton Laboratory, NCAS/BADC; Gonzalez, Estanislao [German Climate Computing Center; Fiore, Sandro [Euro-Mediterranean Center on Climate Change; Schweitzer, Roland [Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration; Danvil, Sebastian [Institut Pierre Simon Laplace (IPSL), Des Sciences de L'Environnement; Morgan, Mark [Institut Pierre Simon Laplace (IPSL), Des Sciences de L'Environnement

    2012-01-01

    The Earth System Grid Federation (ESGF) is a multi-agency, international collaboration that aims at developing the software infrastructure needed to facilitate and empower the study of climate change on a global scale. The ESGF s architecture employs a system of geographically distributed peer nodes, which are independently administered yet united by the adoption of common federation protocols and application programming interfaces (APIs). The cornerstones of its interoperability are the peer-to-peer messaging that is continuously exchanged among all nodes in the federation; a shared architecture and API for search and discovery; and a security infrastructure based on industry standards (OpenID, SSL, GSI and SAML). The ESGF software is developed collaboratively across institutional boundaries and made available to the community as open source. It has now been adopted by multiple Earth science projects and allows access to petabytes of geophysical data, including the entire model output used for the next international assessment report on climate change (IPCC-AR5) and a suite of satellite observations (obs4MIPs) and reanalysis data sets (ANA4MIPs).

  5. The Earth System Grid Federation : an Open Infrastructure for Access to Distributed Geospatial Data

    NASA Technical Reports Server (NTRS)

    Cinquini, Luca; Crichton, Daniel; Mattmann, Chris; Harney, John; Shipman, Galen; Wang, Feiyi; Ananthakrishnan, Rachana; Miller, Neill; Denvil, Sebastian; Morgan, Mark; Pobre, Zed; Bell, Gavin M.; Drach, Bob; Williams, Dean; Kershaw, Philip; Pascoe, Stephen; Gonzalez, Estanislao; Fiore, Sandro; Schweitzer, Roland

    2012-01-01

    The Earth System Grid Federation (ESGF) is a multi-agency, international collaboration that aims at developing the software infrastructure needed to facilitate and empower the study of climate change on a global scale. The ESGF's architecture employs a system of geographically distributed peer nodes, which are independently administered yet united by the adoption of common federation protocols and application programming interfaces (APIs). The cornerstones of its interoperability are the peer-to-peer messaging that is continuously exchanged among all nodes in the federation; a shared architecture and API for search and discovery; and a security infrastructure based on industry standards (OpenID, SSL, GSI and SAML). The ESGF software is developed collaboratively across institutional boundaries and made available to the community as open source. It has now been adopted by multiple Earth science projects and allows access to petabytes of geophysical data, including the entire model output used for the next international assessment report on climate change (IPCC-AR5) and a suite of satellite observations (obs4MIPs) and reanalysis data sets (ANA4MIPs).

  6. Systems with stationary distribution of quantum correlations: open spin-1/2 chains with XY interaction

    NASA Astrophysics Data System (ADS)

    Fel'dman, E. B.; Zenchuk, A. I.

    2013-09-01

    Although quantum correlations in a quantum system are characterized by the evolving quantities (which are entanglement and discord usually), we reveal such basis (i.e. the set of virtual particles) for the representation of the density matrix that the entanglement and/or discord between any two virtual particles in such representation are stationary. In particular, dealing with the nearest neighbor approximation, this system of virtual particles is represented by the ? -fermions of the Jordan-Wigner transformation. Such systems are important in quantum information devices because the evolution of quantum entanglement/discord leads to the problems of realization of quantum operations. The advantage of stationary entanglement/discord is that they are completely defined by the initial density matrix and by the Hamiltonian governing the quantum dynamics in the system under consideration. Moreover, using the special initial condition together with the special system's geometry, we construct large cluster of virtual particles with the same pairwise entanglement/discord. In other words, the measure of quantum correlations is stationary in this system and correlations are uniformly "distributed" among all virtual particles. As examples, we use both homogeneous and non-homogeneous spin-1/2 open chains with XY-interaction although other types of interactions might be also of interest.

  7. Selected papers from Middleware'98: The IFIP International Conference on Distributed Systems Platforms and Open Distributed Processing

    NASA Astrophysics Data System (ADS)

    Davies, Nigel; Raymond, Kerry; Blair, Gordon

    1999-03-01

    In recent years the distributed systems community has witnessed a growth in the number of conferences, leading to difficulties in tracking the literature and a consequent loss of awareness of work done by others in this important research domain. In an attempt to synthesize many of the smaller workshops and conferences in the field, and to bring together research communities which were becoming fragmented, IFIP staged Middleware'98: The IFIP International Conference on Distributed Systems Platforms and Open Distributed Processing. The conference was widely publicized and attracted over 150 technical submissions including 135 full paper submissions. The final programme consisted of 28 papers, giving an acceptance ratio of a little over one in five. More crucially, the programme accurately reflected the state of the art in middleware research, addressing issues such as ORB architectures, engineering of large-scale systems and multimedia. The traditional role of middleware as a point of integration and service provision was clearly intact, but the programme stressed the importance of emerging `must-have' features such as support for extensibility, mobility and quality of service. The Middleware'98 conference was held in the Lake District, UK in September 1998. Over 160 delegates made the journey to one of the UK's most beautiful regions and contributed to a lively series of presentations and debates. A permanent record of the conference, including transcripts of the panel discussions which took place, is available at: http://www.comp.lancs.ac.uk/computing/middleware98/ Based on their original reviews and the reactions of delegates to the ensuing presentations we have selected six papers from the conference for publication in this special issue of Distributed Systems Engineering. The first paper, entitled `Jonathan: an open distributed processing environment in Java', by Dumant et al describes a minimal, modular ORB framework which can be used for supporting real-time and multimedia applications. The framework provides mechanisms by which services such as CORBA ORBs can be constructed as personalities which exploit the services provided by the underlying minimal kernel. The issue of engineering ORBs is taken further in the second paper, `The implementation of a high-performance ORB over multiple network transports' by Lo and Pope. This paper is of particular interest since it presents the concrete results of running a modern ORB, i.e. omniORB2, over a range of transport mechanisms, including TCP/IP, shared memory and ATM AAL5. However, in order for middleware to progress, future platforms must tackle the issue of scalability as well as that of performance. For this reason we have included two papers, `Systems support for scalable and fault tolerant Internet services' by Chawathe and Brewer and `A scalable middleware solution for advanced wide-area Web services' by van Steen et al, which address the problems inherent in developing scalable middleware. Although the two papers focus on different problems in this area, they are both motivated by the explosion of services and information made available through the World Wide Web. Indeed, the role of the World Wide Web as a component in middleware platforms featured prominently in the conference and this is reflected in our choice of the paper by Cao et al entitled `Active Cache: caching dynamic contents on the Web'. Motivated once again by the problems of scalability, Cao et al propose a system to support the caching of dynamic documents. This is achieved by enabling small applets to be cached along with pages and run by the cache servers. The issues of security, trust and resource utilization raised by such a system are explored in detail by the authors. Finally, `Mobile Java objects' by Hayton et al considers these issues still further as part of the authors' work on adding object mobility to Java. Together, the six papers contained within this issue of Distributed Systems Engineering capture the essence of Middleware'98 and demonstrate the progress that has been made in the fi

  8. Guest Editors' Introduction: Selected papers from Middleware'98: The IFIP International Conference on Distributed Systems - Platforms and Open Distributed Processing

    Microsoft Academic Search

    Nigel Davies; Kerry Raymond; Gordon S. Blair

    1999-01-01

    In recent years the distributed systems community has witnessed a growth in the number of conferences, leading to difficulties in tracking the literature and a consequent loss of awareness of work done by others in this important research domain. In an attempt to synthesize many of the smaller workshops and conferences in the field, and to bring together research communities

  9. Wigner distribution function and entropy of the damped harmonic oscillator within the theory of the open quantum systems

    NASA Technical Reports Server (NTRS)

    Isar, Aurelian

    1995-01-01

    The harmonic oscillator with dissipation is studied within the framework of the Lindblad theory for open quantum systems. By using the Wang-Uhlenbeck method, the Fokker-Planck equation, obtained from the master equation for the density operator, is solved for the Wigner distribution function, subject to either the Gaussian type or the delta-function type of initial conditions. The obtained Wigner functions are two-dimensional Gaussians with different widths. Then a closed expression for the density operator is extracted. The entropy of the system is subsequently calculated and its temporal behavior shows that this quantity relaxes to its equilibrium value.

  10. Control of an Open Winding Machine in a Grid-Connected Distributed Generation System

    Microsoft Academic Search

    Mu-Shin Kwak; Seung-Ki Sul

    2006-01-01

    A grid-connected distributed generation system which consists of engine generator, dc link with multiple energy sources and inverter is proposed. All six of the stator leads of the generator, which is a surface mount permanent magnet machine, are brought out to the terminal of the generator. Three leads are connected to the inverter and the others are connected to the

  11. Control of an Open-Winding Machine in a Grid-Connected Distributed Generation System

    Microsoft Academic Search

    Mu-Shin Kwak; Seung-Ki Sul

    2008-01-01

    In this paper, a grid-connected distributed generation system, which consists of engine-generator, DC link with multiple energy sources, and inverter, is proposed. All six of the stator leads of the generator, which is the surface-mount permanent-magnet machine, are brought out to the terminal of the generator. Three leads are connected to the inverter, and the others are connected to the

  12. apART: system for the acquisition, processing, archiving, and retrieval of digital images in an open, distributed imaging environment

    NASA Astrophysics Data System (ADS)

    Schneider, Uwe; Strack, Ruediger

    1992-04-01

    apART reflects the structure of an open, distributed environment. According to the general trend in the area of imaging, network-capable, general purpose workstations with capabilities of open system image communication and image input are used. Several heterogeneous components like CCD cameras, slide scanners, and image archives can be accessed. The system is driven by an object-oriented user interface where devices (image sources and destinations), operators (derived from a commercial image processing library), and images (of different data types) are managed and presented uniformly to the user. Browsing mechanisms are used to traverse devices, operators, and images. An audit trail mechanism is offered to record interactive operations on low-resolution image derivatives. These operations are processed off-line on the original image. Thus, the processing of extremely high-resolution raster images is possible, and the performance of resolution dependent operations is enhanced significantly during interaction. An object-oriented database system (APRIL), which can be browsed, is integrated into the system. Attribute retrieval is supported by the user interface. Other essential features of the system include: implementation on top of the X Window System (X11R4) and the OSF/Motif widget set; a SUN4 general purpose workstation, inclusive ethernet, magneto optical disc, etc., as the hardware platform for the user interface; complete graphical-interactive parametrization of all operators; support of different image interchange formats (GIF, TIFF, IIF, etc.); consideration of current IPI standard activities within ISO/IEC for further refinement and extensions.

  13. Flow Distribution in Hydraulic Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, S. N.

    1983-01-01

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

  14. Mapping of methane spatial distribution around biogas plant with an open-path tunable diode absorption spectroscopy scanning system

    NASA Astrophysics Data System (ADS)

    Zhang, Shirui; Wang, Jihua; Dong, Daming; Zheng, Wengang; Zhao, Xiande

    2013-02-01

    An open-path tunable diode laser absorption spectroscopy (OP-TDLAS) detector was applied to detect the methane emission from a biogas plant in a dairy farm. Two OP-TDLAS scanning systems were built according to maximum likelihood with expectation minimization (MLEM) and smooth basis function minimization (SBFM) algorithms to reconstruct the two-dimensional (2-D) distribution maps. Six reconstruction maps with the resolution of 30×80 were obtained by the MLEM algorithm with "grid translation method" and three reconstruction maps were obtained by the SBFM algorithm with 2-D Gaussian model. The maximum mixing ratio in the first result was between 0.85 and 1.30 ppm, while it was between 1.14 and 1.30 ppm in the second result. The average mixing ratio in the first result was between 0.54 and 0.49 ppm, and between 0.56 and 0.65 ppm in the second result. The reconstruction results validated that the two algorithms could effectively reflect the methane mixing ratio distribution within the target area. However, with the more simple optical rays and less equipment requirements, the OP-TDLAS scanning system based on SBFM algorithm provides a useful monitoring tool of methane emissions in agricultural production.

  15. Implications of an open, extensible, and distributed hypermedia information system architecture for interprocess communication subsystem design

    E-print Network

    Nuernberg, Peter John

    1994-01-01

    communication subsystem does not support dynamic addition of protocols and media definitions as well as dynamic process modification, the supersystem itself cannot be complete with respect to information system services rendered. This aspect of hypermedia system...

  16. ClosestNode.com: an open access, scalable, shared geocast service for distributed systems

    Microsoft Academic Search

    Bernard Wong; Emin Gün Sirer

    2006-01-01

    ClosestNode.com is an accurate, scalable, and backwards-compatible service for mapping clients to a nearby server. It provides a DNS interface by which unmodied clients can look up a service name, and get the IP address of the closest server. A shared system for performing such a mapping amortizes the administration and im- plementation costs of proximity-based server selection. It is

  17. The V distributed system

    Microsoft Academic Search

    David R. Cheriton

    1988-01-01

    The V distributed System was developed at Stanford University as part of a research project to explore issues in distributed systems. Aspects of the design suggest important directions for the design of future operating systems and communication systems.

  18. 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.

  19. SHORT COMMUNICATION Open Access Testing the VEMCO Positioning System: spatial

    E-print Network

    SHORT COMMUNICATION Open Access Testing the VEMCO Positioning System: spatial distribution animals over long periods of time with regular fine-scale positions. The VEMCO Positioning System (VPS Positioning System, Probability of location, Positioning error, Spatial distribution Findings Background

  20. Smart distribution automation system

    Microsoft Academic Search

    C. S?ahin; A. Nadar

    2010-01-01

    Electric distribution systems have been undergoing substantial changes in the recent years, aiming more efficient and cost effective operation. In this paper, new operation philosophies and systems in the literature have been analyzed in parallel with these changes. There are various applications of Distribution automation systems performing automatic fault detection, isolation and restoration. However, these systems fail to identify fault

  1. Quantum Mechanics + Open Systems

    E-print Network

    Steinhoff, Heinz-Jürgen

    Quantum Mechanics + Open Systems = Thermodynamics ? Jochen Gemmer T¨ubingen, 09.02.2006 #12., World Scientific) #12;Fundamental Law or Emergent Description? Quantum Mechanics i t = (- 2 2m + V or Emergent Description? Quantum Mechanics i t = (- 2 2m + V ) "Heisenberg Cut" Classical Mechanics: m d2

  2. Open architecture CNC system

    SciTech Connect

    Tal, J. [Galil Motion Control Inc., Sunnyvale, CA (United States); Lopez, A.; Edwards, J.M. [Los Alamos National Lab., NM (United States)

    1995-04-01

    In this paper, an alternative solution to the traditional CNC machine tool controller has been introduced. Software and hardware modules have been described and their incorporation in a CNC control system has been outlined. This type of CNC machine tool controller demonstrates that technology is accessible and can be readily implemented into an open architecture machine tool controller. Benefit to the user is greater controller flexibility, while being economically achievable. PC based, motion as well as non-motion features will provide flexibility through a Windows environment. Up-grading this type of controller system through software revisions will keep the machine tool in a competitive state with minimal effort. Software and hardware modules are mass produced permitting competitive procurement and incorporation. Open architecture CNC systems provide diagnostics thus enhancing maintainability, and machine tool up-time. A major concern of traditional CNC systems has been operator training time. Training time can be greatly minimized by making use of Windows environment features.

  3. Naval open systems architecture

    NASA Astrophysics Data System (ADS)

    Guertin, Nick; Womble, Brian; Haskell, Virginia

    2013-05-01

    For the past 8 years, the Navy has been working on transforming the acquisition practices of the Navy and Marine Corps toward Open Systems Architectures to open up our business, gain competitive advantage, improve warfighter performance, speed innovation to the fleet and deliver superior capability to the warfighter within a shrinking budget1. Why should Industry care? They should care because we in Government want the best Industry has to offer. Industry is in the business of pushing technology to greater and greater capabilities through innovation. Examples of innovations are on full display at this conference, such as exploring the impact of difficult environmental conditions on technical performance. Industry is creating the tools which will continue to give the Navy and Marine Corps important tactical advantages over our adversaries.

  4. Cooling water distribution system

    DOEpatents

    Orr, Richard (Pittsburgh, PA)

    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.

  5. Networked Software Systems Distributed System

    E-print Network

    Segall, Adrian

    networking APIs. Using the system will allow the developer to run his tasks producer over one computer. The system is platform independent; means it can run over every platform since it is written in Java to a concrete usage: Distributed Search Engine. This concrete system will search pages in the web, download them

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Control of open quantum systems

    E-print Network

    Boulant, Nicolas

    2005-01-01

    This thesis describes the development, investigation and experimental implementation via liquid state nuclear magnetic resonance techniques of new methods for controlling open quantum systems. First, methods that improve ...

  12. Secure software distribution system

    SciTech Connect

    Bartoletti, T.; Dobbs, L.A.; Kelley, M.

    1997-02-01

    Authenticating and upgrading system software plays a critical role in information security, yet practical tools for assessing and installing software are lacking in today`s marketplace. The Secure Software Distribution System (SSDS) will provide automated analysis, notification, distribution, and installation of security patches and related software to network-based computer systems in a vendor-independent fashion. SSDS will assist with the authentication of software by comparing the system`s objects with the patch`s objects. SSDS will monitor vendor`s patch sites to determine when new patches are released and will upgrade system software on target systems automatically. This paper describes the design of SSDS. Motivations behind the project, the advantages of SSDS over existing tools as well as the current status of the project are also discussed. 2 figs.

  13. Investigation of physicochemical characteristics and heavy metal distribution profile in groundwater system around the open dump site

    NASA Astrophysics Data System (ADS)

    Kanmani, S.; Gandhimathi, R.

    2013-06-01

    In this study, the characterization of solid waste and the effect of the leachate from an open dumping site in Ariyamangalam, Tiruchirappalli District, Tamil Nadu, on groundwater is investigated. A total of 14 groundwater samples and 20 leachate samples were collected for monitoring purpose. All the samples were analyzed for various physical and chemical parameters according to standard methods: this includes pH, electrical conductivity, total dissolved solids (TDS), total hardness, and total alkalinity, major cations such as Ca2+, Mg2+, and Fe2+, major anions such as NO3 -, Cl-, and SO4 2- and heavy metals such as Cd, Cu, Mn, Pb, and Zn. The results indicated that, very few parameters such as pH, sulfates and nitrates concentration in the groundwater samples are within the recommended maximum admissible limits approved by WHO (World Health Organization 940-949, 2002) and Bureau of Indian standards (IS 10500:1991). The TDS (range between 740 and 14,200 mg/L) in groundwater reveal the saline behavior of water and was found to be very high according to standards. The range of chlorides in all the locations under investigation is 215.15-4,098.73 mg/L. The contour plots also indicated that the groundwater was rigorously contaminated with various heavy metals. The presence of high concentration of Pb (0.59 mg/L) in groundwater samples nearby dumping site implies that groundwater samples were contaminated by leachate migration from an open dumping site.

  14. Communicating Open Systems

    E-print Network

    Mark d& apos; Inverno; Michael Luck; Pablo Noriega; Juan Rodriguez-Aguilar; Carles Sierra

    2012-01-01

    Just as conventional institutions are organisational structures for coordinating the activities of multiple interacting individuals, electronic institutions provide a computational analogue for coordinating the activities of multiple interacting software agents. In this paper, we argue that open multi-agent systems can be effectively designed and implemented as electronic institutions, for which we provide a comprehensive computational model. More specifically, the paper provides an operational semantics for electronic institutions, specifying the essential data structures, the state representation and the key operations necessary to implement them. We specify the agent workflow structure that is the core component of such electronic institutions and particular instantiations of knowledge representation languages that support the institutional model. In so doing, we provide the first formal account of the electronic institution concept in a rigorous and unambiguous way.

  15. An Open-Source Learning Content Management and Assessment System

    E-print Network

    LON-CAPA An Open-Source Learning Content Management and Assessment System Gerd Kortemeyer-CAPA is free open-source a learning content management system an assessment system around since 1992 #12 Resource Library · The distributed network looks like one big file system ( Um conjunto de Instituições

  16. Open quantum systems and random matrix theory

    SciTech Connect

    Mulhall, Declan [Department of Physics/Engineering, University of Scranton, Scranton, Pennsylvania 18510-4642 (United States)

    2014-10-15

    A simple model for open quantum systems is analyzed with RMT. The system is coupled to the continuum in a minimal way. In this paper we see the effect of opening the system on the level statistics, in particular the level spacing, width distribution and ?{sub 3}(L) statistic are examined as a function of the strength of this coupling. The usual super-radiant state is observed, and it is seen that as it is formed, the level spacing and ?{sub 3}(L) statistic exhibit the signatures of missed levels.

  17. Open quantum systems and Random Matrix Theory

    E-print Network

    Declan Mulhall

    2015-01-09

    A simple model for open quantum systems is analyzed with Random Matrix Theory. The system is coupled to the continuum in a minimal way. In this paper we see the effect of opening the system on the level statistics, in particular the $\\Delta_3(L)$ statistic, width distribution and level spacing are examined as a function of the strength of this coupling. A super-radiant transition is observed, and it is seen that as it is formed, the level spacing and $\\Delta_3(L)$ statistic exhibit the signatures of missed levels.

  18. Open-PEA Space Charge Measurement System

    NASA Astrophysics Data System (ADS)

    Imai, Satoshi; Tanaka, Yasuhiro; Fukao, Tadashi; Takada, Tatsuo; Maeno, Takashi

    The pulsed electro-acoustic (PEA) method has been widely used to observe space charge phenomena in dielectric materials. There have been awaited demands for monitoring space charge phenomena under electron beam or radioactive rays irradiations, or during plasma processing. Therefore we have developed a new PEA space charge measurement system that can observe space charge distributions under such severe conditions. This system uses an open upper electrode that can measure surface and internal space charge profiles at the same time. This paper introduces the 'Open-PEA system' with experimental results obtained during electron irradiation in vacuum.

  19. Seamless Data Distribution System

    NSDL National Science Digital Library

    USGS

    This site from the USGS and the EROS Data Center (EDC) presents the Seamless Data Distribution System (SDDS). The site is the ultimate location for exploration and data retrieval from both the United States and international locations. The site features free data downloads, user defined datasets and area, data acquisition from different government hosts, and elevation point and profile tools.

  20. Distributed Optimization System

    DOEpatents

    Hurtado, John E. (Albuquerque, NM); Dohrmann, Clark R. (Albuquerque, NM); Robinett, III, Rush D. (Tijeras, NM)

    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.

  1. 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.

  2. 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.

  3. Quality monitored distributed voting system

    DOEpatents

    Skogmo, David (Albuquerque, NM)

    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.

  4. Distributed road assessment system

    DOEpatents

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

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

  5. Open source portal to distributed image repositories

    NASA Astrophysics Data System (ADS)

    Tao, Wenchao; Ratib, Osman M.; Kho, Hwa; Hsu, Yung-Chao; Wang, Cun; Lee, Cason; McCoy, J. M.

    2004-04-01

    In large institution PACS, patient data may often reside in multiple separate systems. While most systems tend to be DICOM compliant, none of them offer the flexibility of seamless integration of multiple DICOM sources through a single access point. We developed a generic portal system with a web-based interactive front-end as well as an application programming interface (API) that allows both web users and client applications to query and retrieve image data from multiple DICOM sources. A set of software tools was developed to allow accessing several DICOM archives through a single point of access. An interactive web-based front-end allows user to search image data seamlessly from the different archives and display the results or route the image data to another DICOM compliant destination. An XML-based API allows other software programs to easily benefit from this portal to query and retrieve image data as well. Various techniques are employed to minimize the performance overhead inherent in the DICOM. The system is integrated with a hospital-wide HIPAA-compliant authentication and auditing service that provides centralized management of access to patient medical records. The system is provided under open source free licensing and developed using open-source components (Apache Tomcat for web server, MySQL for database, OJB for object/relational data mapping etc.). The portal paradigm offers a convenient and effective solution for accessing multiple image data sources in a given healthcare enterprise and can easily be extended to multi-institution through appropriate security and encryption mechanisms.

  6. Recent development in open systems for EMS\\/SCADA

    Microsoft Academic Search

    Yutaka Kokai; Fumio Masuda; Satoshi Horiike; Yasuji Sekine

    1998-01-01

    Based on the current situation and emerging trends of development of EMS\\/SCADA systems throughout the world, this report examines the `open system' concept from the viewpoints of users and suppliers. Current technologies for open distributed EMS\\/SCADAs and their possible future trends are described.

  7. Distributed Intrusion Detection System

    NSDL National Science Digital Library

    Internet worms and other malicious code often scan firewalls to determine which ports are unprotected. While firewall users have access to their port scanning data in the form of log files, most do not make use of it. The Distributed Intrusion Detection System remotely monitors trends in worldwide port scanning, and the data it has collected is available at this site. The data can be used by Internet professionals for early detection of worms or for implementing improved security measures. Firewall users can contribute to this project by downloading the free DShield Client, which automatically sends log reports for inclusion in worldwide data or by submitting logs online via a Web interface.

  8. Logical Mapping: An Intermedia Synchronization Model for Multimedia Distributed Systems

    Microsoft Academic Search

    Saul E. Pomares Hernandez; Luis A. Morales Rosales; Jorge Estudillo Ramirez; Gustavo Rodríguez Gómez

    2008-01-01

    The preservation of temporal dependencies among different media data, such as text, still images, video and audio, and which have simultaneous distributed sources as origin, is an open research area and an important issue for emerging distributed multimedia systems, such as Teleimmersion, Telemedicine, and IPTV. Although there are several works oriented to satisfy temporal dependencies in distributed multimedia systems, they

  9. 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.

  10. Dynamics of explosive paroxysms at open andesitic systems: high-resolution mass distribution analyses of 2006 tephra from Tungurahua volcano (Ecuador)

    NASA Astrophysics Data System (ADS)

    Le Pennec, J.; Eychenne, J.; Ramon, P.; Yepes, H.

    2012-12-01

    Many andesitic volcanoes at subduction plate margins can experience in the course of their evolution periods of sub-continuous eruption during years, decades, or centuries. Such long-lived periods may embrace more or less intense outgassing events, extrusion of viscous lava flows and domes (e.g. Colima in Mexico, Merapi in Indonesia, Arenal in Costa Rica), and explosive activity of uneven intensity (e.g. Semeru in Indonesia, Sakurajima in Japan, Sangay in Ecuador). In addition, strong explosive events of short duration may occur, with potential generation of pyroclastic flows on the flanks and beyond, which can pose significant hazards in populated regions. The origin and dynamics of such violent eruptions remain poorly known and may involve a combination of different factors. Tungurahua volcano, Ecuador, reawaken in 1999 and is an example of such open-system behaviour that experienced a strong and deadly andesitic pyroclastic flow-forming event in August 2006. Inspection of the deposits suggested that the event could have been triggered by magma mixing (silicic pumices in the tephra), magma-water interaction (presence of xenolithic clasts) or deep andesitic magma reinjection (based on mineral chemistry). Here we investigate these options by performing a high-resolution mass budget analysis of the scoria fall deposit. This is achieved by analysing componentry compositions and their mass distribution pattern in the layer, which allow us to document and integrate exponential and power laws mass decay rates over wide areas. The results yield a total mass for the tephra layer of ~2 x 1010kg. The pumice mass fraction is far too small (< 0.4 %) to account for the high explosivity of the 2006 event. Similarly, the xenoclastic mass fraction is small (0.2%) and suggests limited magma-water interaction. Instead, we interpret these xenoclasts as a result of upper conduit erosion at a rate of ~30 cm/hour during the paroxysm. Altogether our results support an explosive event fed by a deep gas-rich andesitic reinjection, which would have incorporated a pocket of older differentiated magma and eroded the upper conduit during the sub-plinian event. The high-resolution mass-based approach reveals useful to decipher the origin of the violent 2006 paroxysm and has potential to improve magnitude determinations of ancient eruption by considering componentry mass instead of volume. It is also applicable for monitoring purposes in the context of on-going crises at andesitic volcanoes worldwide.

  11. DISTRIBUTION SYSTEM CONSIDERATIONS FOR TREATMENT

    EPA Science Inventory

    EPA and other research has shown that drinking water distribution systems are active reactors, which can accumulate, release, or transform contaminants during passage from the treatment plant to the consumers’ taps. This presentation discusses the nature of distribution sys...

  12. Wireless distributed functional electrical stimulation system

    PubMed Central

    2012-01-01

    Background The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. Methods The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software. Results The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers). One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. Conclusions The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement. PMID:22876934

  13. Wireless distributed data acquisition system

    Microsoft Academic Search

    Brent Priddy; Emil Jovanov

    2002-01-01

    Distributed data acquisition requires a flexible system organization, particularly when individual devices are mobile. The utility companies have been developing similar systems for several years now. In the case of medical devices, a mobile patient monitoring device would allow patients to leave the hospital and engage in normal activity, uploading physiological data only periodically. The wireless distributed data acquisition system

  14. Open vs. closed Apple music distribution platform

    E-print Network

    Aye, Thida, S.M. Massachusetts Institute of Technology

    2008-01-01

    In this thesis, based on the example case study of the Apple iTunes-iPods platform technology, two simple models are analyzed to gain a better understanding of open vs. closed business models as management and market ...

  15. 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.

  16. A prototype Distributed Audit System

    SciTech Connect

    Banning, D.L. [Sparta, Inc., El Segundo, CA (United States)

    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.

  17. Integrating Distributed Algorithms into Distributed Systems

    E-print Network

    Freytag, Johann-Christoph

    of the Distributed Algorithms' Working Notation (DAWN ). Keywords: Distributed Algorithms; Petri Nets in the setting of the Distributed Algorithms' Working Notation (DAWN) [12, 27, 6, 24]. In DAWN a distributed

  18. FTTlet based distributed system architecture

    Microsoft Academic Search

    Mário J. B. Calha; José A. G. Fonseca

    In this paper an architecture of a distributed embedded system, that offers the advantages of the Java programming model and the flexibility and timeliness of the Flexible Time-Triggered (FTT) paradigm, is presented. The architecture builds on previous work by the authors in which a simple mechanism to dispatch tasks and messages was proposed for CAN-based distributed systems. In order to

  19. The LOCUS Distributed Operating System

    Microsoft Academic Search

    Bruce J. Walker; Gerald J. Popek; Robert English; Charles S. Kline; Greg Thiel

    1983-01-01

    LOCUS Is a distributed operating system which supports transparent access to data through a network wide fllesystem, permits automatic replication of storaget supports transparent distributed process execution, supplies a number of high reliability functions such as nested transactions, and is upward compatible with Unix. Partitioned operation of subnetl and their dynamic merge is also supported. The system has been operational

  20. Evolution in Distributed Heterogeneous Systems

    Microsoft Academic Search

    Premkumar Devanbu; Eric Wohlstadter

    Distributed, heterogeneous systems are becoming very common, as globalized organizations integrate ap- plications running on dierent platforms, possibly written in dierent languages. Component-interoperability standards such as CORBA are critical enablers of this trend. Certain non-functional requirements for such features as security, quality of service, flexible administration are specially critical to distributed hetero- geneous systems. Unfortunately, such requirements are often formulated

  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. OpenRIMS: An Open Architecture Radiology Informatics Management System

    Microsoft Academic Search

    Steve G. Langer

    2002-01-01

    The following are benefits of an integrated picture archiving and communication system\\/radiology information system archive built with open-source tools and methods: open source, inexpensive interfaces can be updated as needed, and reduced risk of redundant and inconsistent data. Also, wide adoption would promote standard data mining tools, reducing user needs to learn multiple methods to perform the same task. A

  3. 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.

  4. Entropy and specific heat for open systems in steady states

    E-print Network

    X. L. Huang; B. Cui; X. X. Yi

    2010-01-27

    The fundamental assumption of statistical mechanics is that the system is equally likely in any of the accessible microstates. Based on this assumption, the Boltzmann distribution is derived and the full theory of statistical thermodynamics can be built. In this paper, we show that the Boltzmann distribution in general can not describe the steady state of open system. Based on the effective Hamiltonian approach, we calculate the specific heat, the free energy and the entropy for an open system in steady states. Examples are illustrated and discussed.

  5. Toward Distributed Declarative Control of Networked Cyber-Physical Systems

    Microsoft Academic Search

    Mark-Oliver Stehr; Minyoung Kim; Carolyn L. Talcott

    2010-01-01

    \\u000a Networked Cyber-Physical Systems (NCPS) present many challenges that are not suitably addressed by existing distributed computing\\u000a paradigms. They must be reactive and maintain an overall situation awareness that emerges from partial distributed knowledge.\\u000a They must achieve system goals through local, asynchronous actions, using (distributed) control loops through which the environment\\u000a provides essential feedback. Typical NCPS are open, dynamic, and heterogeneous

  6. Open solutions to distributed control in ground tracking stations

    NASA Technical Reports Server (NTRS)

    Heuser, William Randy

    1994-01-01

    The advent of high speed local area networks has made it possible to interconnect small, powerful computers to function together as a single large computer. Today, distributed computer systems are the new paradigm for large scale computing systems. However, the communications provided by the local area network is only one part of the solution. The services and protocols used by the application programs to communicate across the network are as indispensable as the local area network. And the selection of services and protocols that do not match the system requirements will limit the capabilities, performance, and expansion of the system. Proprietary solutions are available but are usually limited to a select set of equipment. However, there are two solutions based on 'open' standards. The question that must be answered is 'which one is the best one for my job?' This paper examines a model for tracking stations and their requirements for interprocessor communications in the next century. The model and requirements are matched with the model and services provided by the five different software architectures and supporting protocol solutions. Several key services are examined in detail to determine which services and protocols most closely match the requirements for the tracking station environment. The study reveals that the protocols are tailored to the problem domains for which they were originally designed. Further, the study reveals that the process control model is the closest match to the tracking station model.

  7. Gossiping in distributed systems

    E-print Network

    Penubothu, Muralidhar V

    1994-01-01

    classes: (i) each node knowing the entire graph of the network and (ii) each node knowing only its neighbors. In the schemes with an initiator, the leader initiates the algorithm and subsequently other nodes in the system participate in the algorithm when...

  8. An Open-Source Learning Content Management and Assessment System

    E-print Network

    LON-CAPA An Open-Source Learning Content Management and Assessment System Gerd Kortemeyer Michigan Library Resource Assembly Course Management Resource Assembly Course Management #12;Campus A Campus B-Institutional Resource Library #12;Shared Resource Library · The distributed network looks like one big file system #12

  9. The thermodynamic hamiltonian for open systems

    E-print Network

    Umberto Lucia

    2011-01-06

    The variational method is very important in mathematical and theoretical physics because it allows us to describe the natural systems by physical quantities independently from the frame of reference used. A global and statistical approach have been introduced starting from non-equilibrium thermodynamics, obtaining the principle of maximum entropy generation for the open systems. This principle is a consequence of the lagrangian approach to the open systems. Here it will be developed a general approach to obtain the thermodynamic hamiltonian for the dynamical study of the open systems. It follows that the irreversibility seems to be the fundamental phenomenon which drives the evolution of the states of the open systems.

  10. 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.

  11. OpenRIMS: An Open Architecture Radiology Informatics Management System

    Microsoft Academic Search

    Steve Langer

    2002-01-01

      The benefits of an integrated picture archiving and communication system\\/radiology information system (PACS\\/RIS) archive built\\u000a with open source tools and methods are 2-fold. Open source permits an inexpensive development model where interfaces can be\\u000a updated as needed, and the code is peer reviewed by many eyes (analogous to the scientific model). Integration of PACS\\/RIS\\u000a functionality reduces the risk of inconsistent

  12. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  13. The Echo Distributed File System

    Microsoft Academic Search

    Andrew D. Birrell; Andy Hisgen; Chuck Jerian; Timothy Mann; Garret Swart

    Echo is an ambitious distributed file system. It was designed around a truly global name space. It uses a coherent caching algorithm. It is fault tolerant. And it is real, it was the primary file system for a large group of researchers. Its novel aspects include an extensible \\

  14. Open radio map based indoor navigation system

    Microsoft Academic Search

    Dongsoo Han; Minkyu Lee; Laeyoung Chang; Hyunil Yang

    2010-01-01

    In this presentation, we introduce an open radio map based indoor navigation system. The system is implemented on a Google android phone and tested on 3rd floor, Main-building, KAIST Munji Campus, Korea. The open radio map for the system is constructed by partly participatory approach. That is, the radio map data for rooms and laboratories are collected by ordinary users

  15. Open economy models of distribution and growth Robert A. Blecker*

    E-print Network

    Carlini, David

    Chapter 9 Open economy models of distribution and growth Robert A. Blecker* To appear in: Eckhard-Keynesian macro models for closed economies, the present chapter focuses on extensions of these models the post-Keynesian framework to a global economy that has become much more integrated in the past few

  16. RESEARCH ARTICLE Open Access Complex phylogenetic distribution of a non-

    E-print Network

    RESEARCH ARTICLE Open Access Complex phylogenetic distribution of a non- canonical genetic code in green algae Ellen Cocquyt1* , Gillian H Gile2 , Frederik Leliaert1 , Heroen Verbruggen1 , Patrick J of a representative set of ulvophycean green algae and used a robust green algal phylogeny to evaluate different

  17. DATABASE Open Access Regional distribution of mercury in sediments

    E-print Network

    Boyer, Edmond

    has been established between mercury (Hg) contamination in the Amazon region and gold miningDATABASE Open Access Regional distribution of mercury in sediments of the main rivers of French , Pierre Laporte3 , Dominique Breeze1 and François Blanchard1 Abstract Use of mercury (Hg) for gold

  18. 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.

  19. An integrated distributed generation optimization model for distribution system planning

    Microsoft Academic Search

    W. El-Khattam; Y. Hegazy; M. Salama

    2005-01-01

    Summary form only given. This paper proposes a new integrated model for solving the distribution system planning problem by implementing distributed generation as an attractive option in distribution utilities territories. The proposed model integrates a comprehensive optimization model and planner's experience to achieve optimal sizing and siting of distributed generation. This model aims to minimize distributed generation's investment and operating

  20. A reliability assessment methodology for distribution systems with distributed generation

    Microsoft Academic Search

    Suchismita S. Duttagupta; Chanan Singh

    2006-01-01

    Reliability assessment is of primary importance in designing and planning distribution systems that operate in an economical manner with minimal interruption of customer loads. With the advances in renewable energy sources, distributed generation (DG), is forecasted to increase in distribution networks. This paper presents a new methodology that can be used to quantitatively analyze the reliability of such distribution systems

  1. Probability Distributions in Complex Systems

    E-print Network

    D. Sornette

    2007-07-15

    We review briefly the concepts underlying complex systems and probability distributions. The later are often taken as the first quantitative characteristics of complex systems, allowing one to detect the possible occurrence of regularities providing a step toward defining a classification of the different levels of organization (the ``universality classes''). A rapid survey covers the Gaussian law, the power law and the stretched exponential distributions. The fascination for power laws is then explained, starting from the statistical physics approach to critical phenomena, out-of-equilibrium phase transitions, self-organized criticality, and ending with a large but not exhaustive list of mechanisms leading to power law distributions. A check-list for testing and qualifying a power law distribution from your data is described in 7 steps. This essay enlarges the description of distributions by proposing that ``kings'', i.e., events even beyond the extrapolation of the power law tail, may reveal an information which is complementary and perhaps sometimes even more important than the power law distribution. We conclude a list of future directions.

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

    SciTech Connect

    Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Kueck, John D [ORNL

    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.

  3. 78 FR 11988 - Open Video Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ...47 CFR Part 76 [CS Docket No. 96-46, FCC 96-334] Open Video Systems AGENCY: Federal Communications Commission. ACTION...The final rules modified rules and policies concerning Open Video Systems. DATES: The amendments to 47 CFR 76.1505(d)...

  4. Enhanced distributed energy resource system

    DOEpatents

    Atcitty, Stanley (Albuquerque, NM); Clark, Nancy H. (Corrales, NM); Boyes, John D. (Albuquerque, NM); Ranade, Satishkumar J. (Las Cruces, NM)

    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.

  5. Unconventional and Innovative: The Open Croquet Project. The Systems Librarian

    ERIC Educational Resources Information Center

    Breeding, Marshall

    2005-01-01

    This brief article gives a description of the Open Croquet Project and its applications. The project's Web site describes Croquet as a "combination of computer software and network architecture that supports deep collaboration and resource sharing among large numbers of users within the context of a large-scale distributed information system." One…

  6. Perturbative approach to Markovian open quantum systems

    PubMed Central

    Li, Andy C. Y.; Petruccione, F.; Koch, Jens

    2014-01-01

    The exact treatment of Markovian open quantum systems, when based on numerical diagonalization of the Liouville super-operator or averaging over quantum trajectories, is severely limited by Hilbert space size. Perturbation theory, standard in the investigation of closed quantum systems, has remained much less developed for open quantum systems where a direct application to the Lindblad master equation is desirable. We present such a perturbative treatment which will be useful for an analytical understanding of open quantum systems and for numerical calculation of system observables which would otherwise be impractical. PMID:24811607

  7. 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.

  8. An integrated distributed generation optimization model for distribution system planning

    Microsoft Academic Search

    Walid El-Khattam; Y. G. Hegazy; M. M. A. Salama

    2005-01-01

    This paper proposes a new integrated model for solving the distribution system planning (DSP) problem by implementing distributed generation (DG) as an attractive option in distribution utilities territories. The proposed model integrates a comprehensive optimization model and planner's experience to achieve optimal sizing and siting of distributed generation. This model aims to minimize DG's investment and operating costs, total payments

  9. An Open Distributed Architecture for Sensor Networks for Risk Management

    PubMed Central

    Douglas, John; Usländer, Thomas; Schimak, Gerald; Esteban, J. Fernando; Denzer, Ralf

    2008-01-01

    Sensors provide some of the basic input data for risk management of natural and man-made hazards. Here the word ‘sensors’ covers everything from remote sensing satellites, providing invaluable images of large regions, through instruments installed on the Earth's surface to instruments situated in deep boreholes and on the sea floor, providing highly-detailed point-based information from single sites. Data from such sensors is used in all stages of risk management, from hazard, vulnerability and risk assessment in the pre-event phase, information to provide on-site help during the crisis phase through to data to aid in recovery following an event. Because data from sensors play such an important part in improving understanding of the causes of risk and consequently in its mitigation, considerable investment has been made in the construction and maintenance of highly-sophisticated sensor networks. In spite of the ubiquitous need for information from sensor networks, the use of such data is hampered in many ways. Firstly, information about the presence and capabilities of sensor networks operating in a region is difficult to obtain due to a lack of easily available and usable meta-information. Secondly, once sensor networks have been identified their data it is often difficult to access due to a lack of interoperability between dissemination and acquisition systems. Thirdly, the transfer and processing of information from sensors is limited, again by incompatibilities between systems. Therefore, the current situation leads to a lack of efficiency and limited use of the available data that has an important role to play in risk mitigation. In view of this situation, the European Commission (EC) is funding a number of Integrated Projects within the Sixth Framework Programme concerned with improving the accessibility of data and services for risk management. Two of these projects: ‘Open Architecture and Spatial Data Infrastructure for Risk Management’ (ORCHESTRA, http://www.eu-orchestra.org/) and ‘Sensors Anywhere’ (SANY, http://sany-ip.eu/) are discussed in this article. These projects have developed an open distributed information technology architecture and have implemented web services for the accessing and using data emanating, for example, from sensor networks. These developments are based on existing data and service standards proposed by international organizations. The projects seek to develop the ideals of the EC directive INSPIRE (http://inspire.jrc.it), which was launched in 2001 and whose implementation began this year (2007), into the risk management domain. Thanks to the open nature of the architecture and services being developed within these projects, they can be implemented by any interested party and can be accessed by all potential users. The architecture is based around a service-oriented approach that makes use of Internet-based applications (web services) whose inputs and outputs conform to standards. The benefit of this philosophy is that it is expected to favor the emergence of an operational market for risk management services in Europe, it eliminates the need to replace or radically alter the hundreds of already operational IT systems in Europe (drastically lowering costs for users), and it allows users and stakeholders to achieve interoperability while using the system most adequate to their needs, budgets, culture etc. (i.e. it has flexibility).

  10. Engineering Democracy in Open Agent Systems

    Microsoft Academic Search

    Peter Mcburney; Simon Parsons

    2003-01-01

    How should open agent societies be organized? Should they be democ- racies, and, if so, what types of democracy? We present three normative models of democracy from political philosophy and consider their relevance for the engi- neering of open multi-agent systems: democracy as wise rule by an elite; democ- racy as the exercise of rational consumer choices by voters; and

  11. Open protocol in multi-agent systems

    Microsoft Academic Search

    Gerard A. W. Vreeswijk

    1995-01-01

    Protocols for intelligent agents are difficult to write. This is partially because intelligent agents accommodate their interaction to the situation that arises. As a result, the interaction among intelligent agents cannot be governed by a fixed protocol. In this paper I describe an open protocol paradigm for reasoning in a multi-agent system with decentralized control. An open protocol is a

  12. 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.

  13. Born-Oppenheimer approximation in open systems

    E-print Network

    X. L. Huang; X. X. Yi

    2009-09-16

    We generalize the standard Born-Oppenheimer approximation to the case of open quantum systems. We define the zeroth order Born-Oppenheimer approximation of an open quantum system as the regime in which its effective Hamiltonian can be diagonalized with fixed slowly changing variables. We then establish validity and invalidity conditions for this approximation for two kinds of dissipations--the spin relaxation and the dissipation of center-of-mass motion. As an example, the Born-Oppenheimer approximation of a two-level open system is analyzed.

  14. Distributed measurement and control system based on microcontrollers with automatic program generation

    Microsoft Academic Search

    Miodrag Bolic; Vujo Drndarevic; Branko Samardzic

    2001-01-01

    The paper describes an open architecture microcontroller based distributed measurement and control system with automatic generation of application program. Interpretation of functions and generation of program for control of the newly added distributed unit or distributed unit of a new type connected to the system performs automatically, without user assistance. The elements of the system are interconnected by means of

  15. A Militarized Distributed Processing System

    NASA Astrophysics Data System (ADS)

    Mauriello, R.

    1982-07-01

    This paper describes a Distributed Processing System (DPS) geographically separated, functionally organized, task oriented, and connected on an efficient high-speed serial data bus. Military Systems designers are given the working tools to configure a highly respon-sive and adaptable system capable of being phased into current applications with a minimum of disturbance by utilizing current software, yet providing a means for constantly incor-porating new technology. A 20-Mbit serial data bus with a modified SDLC protocol provides efficient communication between nodes through the use of numerous addressing modes. A dual redundant bus with multiple bus capability provides a highly survivable system. The Litton DPS is a relatively new development and its first application, aboard a U.S. Navy ship, is described.

  16. Open source, open standards, and health care information systems.

    PubMed

    Reynolds, Carl J; Wyatt, Jeremy C

    2011-01-01

    Recognition of the improvements in patient safety, quality of patient care, and efficiency that health care information systems have the potential to bring has led to significant investment. Globally the sale of health care information systems now represents a multibillion dollar industry. As policy makers, health care professionals, and patients, we have a responsibility to maximize the return on this investment. To this end we analyze alternative licensing and software development models, as well as the role of standards. We describe how licensing affects development. We argue for the superiority of open source licensing to promote safer, more effective health care information systems. We claim that open source licensing in health care information systems is essential to rational procurement strategy. PMID:21447469

  17. 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.

  18. Distributed snapshots: determining global states of distributed systems

    Microsoft Academic Search

    Leslie Lamport

    1985-01-01

    This paper presents an algorithm by which a process in a distributed system determines a global state of the system during a computation. Many problems in distributed systems can be cast in terms of the problem of detecting global states. For instance, the global state detection algorithm helps to solve an important class of problems: stable property detection. A stable

  19. 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.

  20. Measuring Advances in HVAC Distribution System Design

    Microsoft Academic Search

    Franconi

    1998-01-01

    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

  1. Measuring advances in HVAC distribution system designs

    Microsoft Academic Search

    Franconi

    1998-01-01

    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

  2. Distribution System Voltage Regulation by Distributed Energy Resources

    SciTech Connect

    Ceylan, Oguzhan [ORNL; Liu, Guodong [ORNL; Xu, Yan [ORNL; Tomsovic, Kevin [University of Tennessee, Knoxville (UTK)

    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.

  3. 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

  4. 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.

  5. 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 SATCOM services that could be available in the 2005 time frame. The alternatives were evaluated and compared in terms of average daily system throughput and cost per bit. Throughput was estimated based on hypothetical scenarios supporting the International Space Station and polar orbiting missions. The feasibility of using standard TCP and a modified TCP was evaluated and risks were identified. An estimate of the TCP acknowledgment data rate required to support a return channel rate of 622 Mbps was developed using OPNET.

  6. On the controllability of?distributed?systems

    PubMed Central

    Lions, J. L.

    1997-01-01

    To “control” a system is to make it behave (hopefully) according to our “wishes,” in a way compatible with safety and ethics, at the least possible cost. The systems considered here are distributed—i.e., governed (modeled) by partial differential equations (PDEs) of evolution. Our “wish” is to drive the system in a given time, by an adequate choice of the controls, from a given initial state to a final given state, which is the target. If this can be achieved (respectively, if we can reach any “neighborhood” of the target) the system, with the controls at our disposal, is exactly (respectively, approximately) controllable. A very general (and fuzzy) idea is that the more a system is “unstable” (chaotic, turbulent) the “simplest,” or the “cheapest,” it is to achieve exact or approximate controllability. When the PDEs are the Navier–Stokes equations, it leads to conjectures, which are presented and explained. Recent results, reported in this expository paper, essentially prove the conjectures in two space dimensions. In three space dimensions, a large number of new questions arise, some new results support (without proving) the conjectures, such as generic controllability and cases of decrease of cost of control when the instability increases. Short comments are made on models arising in climatology, thermoelasticity, non-Newtonian fluids, and molecular chemistry. The Introduction of the paper and the first part of all sections are not technical. Many open questions are mentioned in the text. PMID:11038539

  7. 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.

  8. Defining A Distribution System for Computer-Controlled Distribution Automation

    Microsoft Academic Search

    L. V. Mccall; B. J. Chambers

    1983-01-01

    For the purpose of implementing computer-based distribution automation, the electrical distribution system to which it is applied must be defined in digital terms for development of an accurate data base and correct and efficient control functions. This paper describes the method used in a current Ontario Hydro project, employing modular elements for system description. This is seen as one of

  9. Optimal operation of distribution power system including distributed generator

    Microsoft Academic Search

    J. Shu; S. S. Quan; L. Z. Zhang

    2010-01-01

    A new model for distribution system reconfiguration (DSR) integrated with optimal power flow (OPF) and optimal capacitor switching (OCS) based on a hybrid approach is proposed in this paper. The objective is to minimize the generation cost of the whole distribution power system, and is subject to constraints such as capacity limit of branches, minimum and maximum power limits of

  10. 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.

  11. Grid-connected distributed solar power systems

    Microsoft Academic Search

    R. Moyle; H. Chernoff; T. Schweizer

    1982-01-01

    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

  12. THE SPATIAL DISTRIBUTION OF STARS IN OPEN CLUSTERS

    SciTech Connect

    Sanchez, Nestor; Alfaro, Emilio J. [Instituto de Astrofisica de Andalucia, CSIC, Apdo. 3004, E-18080, Granada (Spain)], E-mail: nestor@iaa.es

    2009-05-10

    The analysis of the distribution of stars in open clusters may yield important information on the star formation process and early dynamical evolution of stellar clusters. Here we address this issue by systematically characterizing the internal spatial structure of 16 open clusters in the Milky Way spanning a wide range of ages. Cluster stars have been selected from a membership probability analysis based on a nonparametric method that uses both positions and proper motions and does not make any a priori assumption on the underlying distributions. The internal structure is then characterized by means of the minimum spanning tree method (Q parameter), King profile fitting, and the correlation dimension (D{sub c} ) for those clusters with fractal patterns. On average, clusters with fractal-like structure are younger than those exhibiting radial star density profiles and an apparent trend between Q and age is observed in agreement with previous ideas about the dynamical evolution of the internal spatial structure of stellar clusters. However, some new results are obtained from a more detailed analysis: (1) a clear correlation between Q and the concentration parameter of the King model for those cluster with radial density profiles, (2) the presence of spatial substructure in clusters as old as {approx}100 Myr, and (3) a significant correlation between fractal dimension and age for those clusters with internal substructure. Moreover, the lowest fractal dimensions seem to be considerably smaller than the average value measured in galactic molecular cloud complexes.

  13. Open Multi-Agent Systems: Agent

    E-print Network

    Utrecht, Universiteit

    that facilitate the communication process in a multi-agent system. These agents, referred to with terms like facilitators, routers, mediators, bro- kers and so on (cf. [8]) act as intermediaries between communicatingOpen Multi-Agent Systems: Agent Communication and Integration Rogier M. van Eijk, Frank S. de Boer

  14. Scaling of Beowulf-class distributed systems

    Microsoft Academic Search

    John K. Salmon; Christopher Stein; Thomas Sterling

    1998-01-01

    Beowulf-class systems employ inexpensive commodity processors, open source operating systems and communication libraries and commodity networking hardware to deliver supercomputer performance at the lowest possible price. Small to medium sized Beowulf systems are installed or planned at dozens of universities, laboratories and industrial sites around the world. The design space for larger systems, however, is largely unexplored.We investigate two interconnection

  15. On-Site Wastewater Treatment Systems: Spray Distribution System (Spanish)

    E-print Network

    Lesikar, Bruce J.; Enciso, Juan

    2002-04-18

    Spray distribution systems for wastewater are much like lawn sprinkler systems, in that they spray treated wastewater over the surface of a yard. This publication explains how spray distribution systems work, what their design requirements are...

  16. 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.

  17. Embedding measurement in Distribution Automation Systems

    Microsoft Academic Search

    A. Moreno-Muñoz; R. J. Real-Calvo; V. Pallare?s

    2010-01-01

    Actual distribution networks have not been designed to accept extensive Distributed Generation (DG). The present framework may change in the near future impelled by a worldwide increasing of DG penetration in distribution grids. The mutual dependency of energy distribution and communication on the same grid requires new means to effectively monitor and control both systems in parallel. Relaying and control

  18. Location based placement of whole distributed systems

    Microsoft Academic Search

    David Spence; Jon Crowcroft; Steven Hand; Tim Harris

    2005-01-01

    The high bandwidth and low latency of the modern internet has made possible the deployment of distributed computing platforms. The XenoServe platform provides a distributed computing platform open to all and presents three major new challenges for resource discovery: Firstly, network location is key for effectively provisioning services, to mitigate against high-latency, high-load or component failure. Secondly, many services require

  19. Virtual PACS, open systems, and the National Information Infrastructure

    NASA Astrophysics Data System (ADS)

    Wilson, Dennis L.; Prior, Fred W.; Glicksman, Robert A.

    1995-05-01

    Teleradiology and telemedicine move images and related patient data from one medical treatment facility to another. Higher speed communication systems are rapidly being deployed as the national information infrastructure evolves. Demonstration projects have shown that higher performance networks permit an expanded scope of capabilities beyond simple image transmission to full PACS services at a distance. A virtual PACS that ties together several local PACS services is considdred. The interchange of informtion such that each of the local PACS knows about activity around the system is required. The database that tracks the acquisition of new medical exams may be distributed or may be centralized. A distributed database is proposed. Ramifications of the distributed virtual PACS include the possibility of restricting some services to be local and other services to be global. The virtual PACS will enable such things as a virtual radiology department with radiology specialists located at different places through the system. Sharing of specialists will increase their utilization, improve patient outcomes and reduce overall costs by reducing the need for every subspecialty at every location. Virtual PACS may be seen as a set of applications and services within the broader telecommunications framework of the national information infrastructure (NII). As such virtual PACS must be `open systems.' As defined here, an open system in the narrow sense requires a software platform that is widely supported and hardware independent. An open system is based on standards that are widely accepted and for which software is readily available from multiple sources. In the broader sense an open system is a set of services with standard interfaces distributed on a network and sharing common communication facilities. The NII depends on global consensus on appropriate standards. It is vital that medical image and information service components of the NII be carefully defined. The DICOM standard has been shown to be a key component of a global medical communication strategy and capable of forming the basis for constructing a virtual PACS. It is one of several complimentary standards that will be required for global open systems. To be useful in supporting radiology groups the NII should provide economical 2 to 10 megabyte per second services, considerably beyond the data rates available on the Internet today. Communication rates as low as 200 kilobytes per second (1.6 megabits per second) will introduce delays in service, but may be acceptable. Rates below about 64 kilobits per second destroy the utility of a radiology group serving a large area.

  20. Programming assistance over distributed systems: MAPES

    Microsoft Academic Search

    Eric Monacelli; Dominique Duhaut; Daniel Fontaine

    1993-01-01

    This paper presents a task-level programming system for distributed applications in manufacturing robotics, including assistance, named MAPES\\/IAda. Indeed, this system allows a programming aided method for an operator, during off-line and online phases. A such system must answer to requirements of robotics systems: distributed application, real-time execution, executing control increased of programming assistance

  1. Integration of distributed generators into a real powerless distribution system

    Microsoft Academic Search

    Samir Avdakovic; A. Lukac

    2009-01-01

    This paper considers the problem of integrating distributed generators into the Bosnia and Herzegovina's (B&H) distribution system. B&H has a respectable hydro potential accommodation for small hydro power plants (HPP). Today, an imposing number of small hydro power plants (27 units\\/ 36.5 MW) is connected to the B&H distribution grid and tenths are in the phase of construction (total power

  2. Repeated interactions in open quantum systems

    SciTech Connect

    Bruneau, Laurent, E-mail: laurent.bruneau@u-cergy.fr [Laboratoire AGM, Université de Cergy-Pontoise, Site Saint-Martin, BP 222, 95302 Cergy-Pontoise (France); Joye, Alain, E-mail: Alain.Joye@ujf-grenoble.fr [Institut Fourier, UMR 5582, CNRS-Université Grenoble I, BP 74, 38402 Saint-Martin d’Hères (France); Merkli, Marco, E-mail: merkli@mun.ca [Department of Mathematics and Statistics Memorial University of Newfoundland, St. John's, NL Canada A1C 5S7 (Canada)

    2014-07-15

    Analyzing the dynamics of open quantum systems has a long history in mathematics and physics. Depending on the system at hand, basic physical phenomena that one would like to explain are, for example, convergence to equilibrium, the dynamics of quantum coherences (decoherence) and quantum correlations (entanglement), or the emergence of heat and particle fluxes in non-equilibrium situations. From the mathematical physics perspective, one of the main challenges is to derive the irreversible dynamics of the open system, starting from a unitary dynamics of the system and its environment. The repeated interactions systems considered in these notes are models of non-equilibrium quantum statistical mechanics. They are relevant in quantum optics, and more generally, serve as a relatively well treatable approximation of a more difficult quantum dynamics. In particular, the repeated interaction models allow to determine the large time (stationary) asymptotics of quantum systems out of equilibrium.

  3. Open quantum systems with loss and gain

    E-print Network

    Hichem Eleuch; Ingrid Rotter

    2014-09-09

    We consider different properties of small open quantum systems coupled to an environment and described by a non-Hermitian Hamilton operator. Of special interest is the non-analytical behavior of the eigenvalues in the vicinity of singular points, the so-called exceptional points (EPs), at which the eigenvalues of two states coalesce and the corresponding eigenfunctions are linearly dependent from one another. The phases of the eigenfunctions are not rigid in approaching an EP and providing therewith the possibility to put information from the environment into the system. All characteristic properties of non-Hermitian quantum systems hold true not only for natural open quantum systems that suffer loss due to their embedding into the continuum of scattering wavefunctions. They appear also in systems coupled to different layers some of which provide gain to the system. Thereby gain and loss, respectively, may be fixed inside every layer, i.e. characteristic of it.

  4. 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.

  5. Automatic software upgrades for distributed systems

    E-print Network

    Ajmani, Sameer, 1976-

    2004-01-01

    Upgrading the software of long-lived, highly-available distributed systems is difficult. It is not possible to upgrade all the nodes in a system at once, since some nodes may be unavailable and halting the system for an ...

  6. Automatic Software Upgrades for Distributed Systems

    E-print Network

    Ajmani, Sameer

    2005-11-30

    Upgrading the software of long-lived, highly-available distributed systems is difficult. It is not possible to upgrade all the nodes in a system at once, since some nodes may be unavailable and halting the system for an ...

  7. COMMUNICATION SYSTEMS AND STUDY METHOD FOR ACTIVE DISTRIBUTION POWER SYSTEMS

    E-print Network

    Chen, Zhe

    to the distribution power system with active renewable energy based generation units is discussed. Subsequently is configured and studied by the OPNET, and the performance of an active distribution power system integrated1 COMMUNICATION SYSTEMS AND STUDY METHOD FOR ACTIVE DISTRIBUTION POWER SYSTEMS Mu Wei, Zhe Chen

  8. Universal simulation of Markovian open quantum systems

    E-print Network

    Ryan Sweke; Ilya Sinayskiy; Denis Bernard; Francesco Petruccione

    2015-04-07

    We consider the problem of constructing a "universal set" of Markovian processes, such that any Markovian open quantum system, described by a one-parameter semigroup of quantum channels, can be simulated through sequential simulations of processes from the universal set. In particular, for quantum systems of dimension $d$, we explicitly construct a universal set of semigroup generators, parametrized by $d^2-3$ continuous parameters, such that in order to simulate the dynamics of an arbitrary $d$ dimensional Markovian quantum system it is necessary and sufficient to be able to implement unitary operations on the system, and quantum channels from the semigroups generated by elements of the universal set of generators. Furthermore, assuming the ability to implement operations from the universal set, we provide an explicit algorithm for the efficient simulation of Markovian open quantum systems for which the number of distinct Lindblad operators scales polynomially with respect to the number of subsystems.

  9. DebCheck: Efficient Checking for Open Source Code Clones in Software Systems James R Cordy

    E-print Network

    Cordy, James R.

    DebCheck: Efficient Checking for Open Source Code Clones in Software Systems James R Cordy Queen, Canada Email: croy@cs.usask.ca Abstract--The problem of finding code cloned from open source code is the collection of eight DVDs in the Debian source distribution, and checking for cross-cloning with the Debian

  10. 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.

  11. Low jitter RF distribution system

    DOEpatents

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

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

  12. Applying epoch-era analysis for homeowner selection of distributed generation power systems

    E-print Network

    Piña, Alexander L

    2014-01-01

    The current shift from centralized energy generation to a more distributed model has opened a number of choices for homeowners to provide their own power. While there are a number of systems to purchase, there are no tools ...

  13. Open Source Course Management and Assessment System

    E-print Network

    LON-CAPA: Open Source Course Management and Assessment System Gerd Kortemeyer Michigan State, homework problems) is a lot of work · Doing so for use in just one course is a waste of time and effort Assembly Course Management Resource Assembly Course Management #12;Campus A Campus B Resource Assembly

  14. Reliability evaluation of distribution system containing microgrid

    Microsoft Academic Search

    Liang Huishi; Su Jian; Liu Sige

    2010-01-01

    This paper presents a simulative technique to evaluate the reliability of distribution system including distributed generations (DGs) and energy storage system, which compose microgrids with load. The introduction of energy storage system will play an important role on the stable of power supply in microgrids where renewable energy DGs are connected. Stochastic characteristic of photovoltaic and wind power DGs is

  15. Distributed multiparty desktop conferencing system: MERMAID

    Microsoft Academic Search

    Kazuo Watabe; Shiro Sakata; Kazutoshi Maeno; Hideyuki Fukuoka; Toyoko Ohmori

    1990-01-01

    This describes a distributed multiparty desktop conferencing system (MERMAID) and presents its preliminary brief evaluation, obtained as a result of daily use. MERMAID, which is designed based on group collaboration system architecture, provides an environment for widely distributed participants, seated at their desks, to hold real-time conferences by interchanging information through video, voice, and multimedia documents. This system is implemented

  16. DAVID: NASA's heterogeneous distributed database management system

    Microsoft Academic Search

    Bharat Bhasker; Shou-Hsuan Stephen Huang; Barry E. Jacobs

    1990-01-01

    The DAVID (Distributed Access View Integrated Database) system is a heterogeneous distributed database management system developed by NASA. The goal of the project is to integrate current and future NASA data systems into one that can be accessed through several layers of user interfaces with one query language. A description is given of the database aspect of the DAVID project.

  17. 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.

  18. WATER DISTRIBUTION SYSTEM OPERATION: APPLICATION OF

    E-print Network

    Mays, Larry W.

    CHAPTER 5 WATER DISTRIBUTION SYSTEM OPERATION: APPLICATION OF SIMULATED ANNEALING Fred E. Goldman Arizona State University, Tempe, Arizona 5.1 INTRODUCTION The operation of water distribution systems affects the water quality in these systems. EPA regulations require that water quality be maintained

  19. Superadiabatic dynamics in open quantum systems

    E-print Network

    G. Vacanti; R. Fazio; S. Montangero; G. M. Palma; M. Paternostro; V. Vedral

    2014-05-08

    We extend the concept of superadiabatic dynamics, or transitionless quantum driving, to quantum open systems whose evolution is governed by a master equation in the Lindblad form. We provide the general framework needed to determine the control strategy required to achieve superadiabaticity. We apply our formalism to two examples consisting of a two-level system coupled to environments with time-dependent bath operators.

  20. Task allocation in a distributed computing system

    NASA Technical Reports Server (NTRS)

    Seward, Walter D.

    1987-01-01

    A conceptual framework is examined for task allocation in distributed systems. Application and computing system parameters critical to task allocation decision processes are discussed. Task allocation techniques are addressed which focus on achieving a balance in the load distribution among the system's processors. Equalization of computing load among the processing elements is the goal. Examples of system performance are presented for specific applications. Both static and dynamic allocation of tasks are considered and system performance is evaluated using different task allocation methodologies.

  1. Programming languages for distributed computing systems

    Microsoft Academic Search

    Henri E. Bal; Jennifer G. Steiner; Andrew S. Tanenbaum

    1989-01-01

    When distributed systems first appeared, they were programmed in traditional sequential languages, usually with the addition of a few library procedures for sending and receiving messages. As distributed applications became more commonplace and more sophisticated, this ad hoc approach became less satisfactory. Researchers all over the world began designing new programming languages specifically for implementing distributed applications. These languages and

  2. Object management in distributed information systems

    Microsoft Academic Search

    Peter Lyngbaek; Dennis McLeod

    1984-01-01

    A simple model for object sharing in distributed office information systems is described. The model provides a small set of operators for object definition, manipulation, and retrieval in a distributed environment, modeled as a logical network of workstations. Relationships among objects can be established across work station boundaries, objects are relocatable within the distributed environment, and mechanisms are provided for

  3. 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.

  4. Multicanonical distribution: statistical equilibrium of multiscale systems.

    PubMed

    Salazar, Domingos S P; Vasconcelos, Giovani L

    2012-11-01

    A multicanonical formalism is introduced to describe the statistical equilibrium of complex systems exhibiting a hierarchy of time and length scales, where the hierarchical structure is described as a set of nested "internal heat reservoirs" with fluctuating "temperatures." The probability distribution of states at small scales is written as an appropriate averaging of the large-scale distribution (the Boltzmann-Gibbs distribution) over these effective internal degrees of freedom. For a large class of systems the multicanonical distribution is given explicitly in terms of generalized hypergeometric functions. As a concrete example, it is shown that generalized hypergeometric distributions describe remarkably well the statistics of acceleration measurements in Lagrangian turbulence. PMID:23214728

  5. Extracting Overlay Invariants of Distributed Systems for Autonomic System Management

    Microsoft Academic Search

    Hanhuai Shan; Guofei Jiang; Kenji Yoshihira

    2010-01-01

    Many large-scale distributed systems have been built with great complexity to run Internet services. Due to the heterogeneity and dynamics of complex systems, it is very difficult to characterize their behavior precisely for system management. While we collect large amount of monitoring data from distributed systems as system observables, it is hard for us to interpret the data without constructing

  6. Computational field model: toward a new computing model\\/methodology for open distributed environment

    Microsoft Academic Search

    Mario Tokoro

    1990-01-01

    A computing model, called a computational field model, is proposed for solving a problem in an object-oriented open distributed environment. In this model an open-ended distributed environment is envisaged as a continuous computational field. The notions of mass, distance, gravitational force, repulsive force, and inertia of objects are introduced to define a metric space for the field, so that objects

  7. Vertical distribution of phytoplankton communities in open ocean: An assessment based on surface chlorophyll

    E-print Network

    Claustre, Hervé

    Vertical distribution of phytoplankton communities in open ocean: An assessment based on surface. Morel, and S. B. Hooker (2006), Vertical distribution of phytoplankton communities in open ocean- ward in order to encompass the entire depth range where algae can live and grow. For instance

  8. The Center for Networking and Distributed Systems

    NSDL National Science Digital Library

    The Center for Networking and Distributed Systems and John Hopkins University "focuses on the interplay between theory and practice in distributed systems and networks." There are many resources on the centerâ??s Web site, including numerous research papers and publications. One of the papers listed will appear in the IEEE International Conference on Distributed Computing Systems in July 2002. Many of the centerâ??s research projects are described, which are investigating areas such as distributed clustering and metacomputing. There is also specialized software that can be downloaded free of charge under certain conditions.

  9. The Digital Distributed System Security Architecture

    Microsoft Academic Search

    Andy Goldstein; Butler Lampson; Charlie Kaufman; Morrie Gasser

    1989-01-01

    The Digital Distributed System Security Architecture is a comprehensive specification for security in a distributed system that employs state-of-the-art concepts to address the needs of both commercial and government environments. The architecture covers user and system authentication, mandatory and discretionary security, secure initialization and loading, and delegation in a general-purpose computing environment of heterogeneous systems where there are no central

  10. 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.

  11. LMPI: MPI for Heterogeneous Embedded Distributed Systems

    Microsoft Academic Search

    Adnan Agbaria; Dong-in Kang; Karandeep Singh

    2006-01-01

    Message passing interface (MPI) is an important standard that allows message-passing applications to run on many heterogeneous message-passing distributed systems without any change. There are a tremendous number of MPI implementations that are, however, mainly dedicated for traditional distributed systems. Most of these implementations consume a significant amount of resources. In addition to the high resource consumption, the existing MPI

  12. 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...

  13. 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...

  14. Vulnerability Assessment of Regional Water Distribution Systems

    Microsoft Academic Search

    Baoyu Zhuang; Xinhua Zhao; Yuan Zhao

    2009-01-01

    A vulnerability assessment model for regional water distribution system (VAMRWDS) is presented. The model takes into account the impact of residual chlorine and water age, as well as the uncertainty and probabilistic characteristic of the distribution systems. Monte-Carlo stochastic simulation is adopted in the model to randomly generate bulk and wall reaction coefficients. Employing the EPANET toolkit as the hydraulic

  15. A scalable distributed information management system

    Microsoft Academic Search

    Praveen Yalagandula; Michael Dahlin

    2004-01-01

    We present a Scalable Distributed Information Management System (SDIMS) that information about large-scale networked systems and that can serve as a basic building block for a broad range of large-scale distributed applications by providing detailed views of nearby information and summary views of global information. To serve as a basic building block, a SDIMS should have four properties: scalability to

  16. A scalable distributed information management system

    Microsoft Academic Search

    Praveen Yalagandula; Mike Dahlin

    2004-01-01

    We present a Scalable Distributed Information Management System (SDIMS) that aggregates information about large-scale networked systems and that can serve as a basic building block for a broad range of large-scale distributed applications by providing detailed views of nearby information and summary views of global information. To serve as a basic building block, a SDIMS should have four properties: scalability

  17. Hybrid solar lighting distribution systems and components

    DOEpatents

    Muhs, Jeffrey D. (Lenoir City, TN); Earl, Dennis D. (Knoxville, TN); Beshears, David L. (Knoxville, TN); Maxey, Lonnie C. (Powell, TN); Jordan, John K. (Oak Ridge, TN); Lind, Randall F. (Lenoir City, TN)

    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.

  18. Distributed power allocation for vehicle management systems

    Microsoft Academic Search

    Necmiye Ozay; Ufuk Topcu; Richard M. Murray

    2011-01-01

    We consider the problem of designing distributed control protocols -for aircraft vehicle management systems-that cooperatively allocate electric power while meeting certain higher level goals and requirements, and dynamically reacting to the changes in the internal system state and external environment. A decentralized control problem is posed where each power distribution unit is equipped with a controller that implements a local

  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. Feynman's Clock for open quantum systems

    E-print Network

    David G. Tempel; Alan Aspuru-Guzik

    2014-06-21

    We show that Feynman's Clock construction, in which the time-evolution of a closed quantum system is encoded as a ground state problem, can be extended to open quantum systems. In our formalism, the ground states of an ensemble of non-Hermitian Feynman Clock Hamiltonians yield stochastic trajectories, which unravel the evolution of a Lindblad master equation. In this way, one can use Feynman's Clock not only to simulate the evolution of a quantum system, but also it's interaction with an environment such as a heat bath or measuring apparatus. A simple numerical example of a two-level atom undergoing spontaneous emission is presented and analyzed.

  1. Shear flow pumping in open microfluidic systems

    E-print Network

    Markus Rauscher; S. Dietrich; Joel Koplik

    2006-10-26

    We propose to drive open microfluidic systems by shear in a covering fluid layer, e.g., oil covering water-filled chemical channels. The advantages as compared to other means of pumping are simpler forcing and prevention of evaporation of volatile components. We calculate the expected throughput for straight channels and show that devices can be built with off-the-shelf technology. Molecular dynamics simulations suggest that this concept is scalable down to the nanoscale.

  2. Periodically driven quantum open systems: Tutorial

    E-print Network

    Robert Alicki; David Gelbwaser-Klimovsky; Gershon Kurizki

    2012-05-21

    We present a short derivation and discussion of the master equation for an open quantum system weakly coupled to a heat bath and then its generalization to the case of with periodic external driving based on the Floquet theory. Further, a single heat bath is replaced by several ones. We present also the definition of heat currents which satisfies the second law of thermodynamics and apply the general results to a simple model of periodically modulated qubit.

  3. Periodically driven quantum open systems: Tutorial

    E-print Network

    Alicki, Robert; Kurizki, Gershon

    2012-01-01

    We present a short derivation and discussion of the master equation for an open quantum system weakly coupled to a heat bath and then its generalization to the case of with periodic external driving based on the Floquet theory. Further, a single heat bath is replaced by several ones. We present also the definition of heat currents which satisfies the second law of thermodynamics and apply the general results to a simple model of periodically modulated qubit.

  4. Complex Time Evolution of Open Quantum Systems

    E-print Network

    C. N. Gagatsos; A. I. Karanikas; G. I. Kordas

    2011-04-19

    We combine, in a single set-up,the complex time parametrization in path integration, and the closed time formalism of non-equilibrium field theories to produce a compact representation of the time evolution of the reduced density matrix. In this framework we introduce a cluster-type expansion that facilitates perturbative and non-perturbative calculations in the realm of open quantum systems. The technical details of some very simple examples are discussed.

  5. Derivation of hydrous pyrolysis kinetic parameters from open-system pyrolysis

    NASA Astrophysics Data System (ADS)

    Tseng, Yu-Hsin; Huang, Wuu-Liang

    2010-05-01

    Kinetic information is essential to predict the temperature, timing or depth of hydrocarbon generation within a hydrocarbon system. The most common experiments for deriving kinetic parameters are mainly by open-system pyrolysis. However, it has been shown that the conditions of open-system pyrolysis are deviant from nature by its low near-ambient pressure and high temperatures. Also, the extrapolation of heating rates in open-system pyrolysis to geological conditions may be questionable. Recent study of Lewan and Ruble shows hydrous-pyrolysis conditions can simulate the natural conditions better and its applications are supported by two case studies with natural thermal-burial histories. Nevertheless, performing hydrous pyrolysis experiment is really tedious and requires large amount of sample, while open-system pyrolysis is rather convenient and efficient. Therefore, the present study aims at the derivation of convincing distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data. Our results unveil that there is a good correlation between open-system Rock-Eval parameter Tmax and the activation energy (Ea) derived from hydrous pyrolysis. The hydrous pyrolysis single Ea can be predicted from Tmax based on the correlation, while the frequency factor (A0) is estimated based on the linear relationship between single Ea and log A0. Because the Ea distribution is more rational than single Ea, we modify the predicted single hydrous pyrolysis Ea into distributed Ea by shifting the pattern of Ea distribution from open-system pyrolysis until the weight mean Ea distribution equals to the single hydrous pyrolysis Ea. Moreover, it has been shown that the shape of the Ea distribution is very much alike the shape of Tmax curve. Thus, in case of the absence of open-system Ea distribution, we may use the shape of Tmax curve to get the distributed hydrous pyrolysis Ea. The study offers a new approach as a simple method for obtaining distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data, which will allow for better estimating hydrocarbon generation.

  6. 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.

  7. An open system for intravascular ultrasound imaging.

    PubMed

    Qiu, Weibao; Chen, Yan; Li, Xiang; Yu, Yanyan; Cheng, Wang Fai; Tsang, Fu Keung; Zhou, Qifa; Shung, K Kirk; Dai, Jiyan; Sun, Lei

    2012-10-01

    Visualization of the blood vessels can provide valuable morphological information for diagnosis and therapy strategies for cardiovascular disease. Intravascular ultrasound (IVUS) is able to delineate internal structures of vessel wall with fine spatial resolution. However, the developed IVUS is insufficient to identify the fibrous cap thickness and tissue composition of atherosclerotic lesions. Novel imaging strategies have been proposed, such as increasing the center frequency of ultrasound or using a modulated excitation technique to improve the accuracy of diagnosis. Dual-mode tomography combining IVUS with optical tomography has also been developed to determine tissue morphology and characteristics. The implementation of these new imaging methods requires an open system that allows users to customize the system for various studies. This paper presents the development of an IVUS system that has open structures to support various imaging strategies. The system design is based on electronic components and printed circuit board, and provides reconfigurable hardware implementation, programmable image processing algorithms, flexible imaging control, and raw RF data acquisition. In addition, the proposed IVUS system utilized a miniaturized ultrasound transducer constructed using PMNPT single crystal for better piezoelectric constant and electromechanical coupling coefficient than traditional lead zirconate titanate (PZT) ceramics. Testing results showed that the IVUS system could offer a minimum detectable signal of 25 ?V, allowing a 51 dB dynamic range at 47 dB gain, with a frequency range from 20 to 80 MHz. Finally, phantom imaging, in vitro IVUS vessel imaging, and multimodality imaging with photoacoustics were conducted to demonstrate the performance of the open system. PMID:23143570

  8. An Open System for Intravascular Ultrasound Imaging

    PubMed Central

    Qiu, Weibao; Chen, Yan; Li, Xiang; Yu, Yanyan; Cheng, Wang Fai; Tsang, Fu Keung; Zhou, Qifa; Shung, K. Kirk; Dai, Jiyan; Sun, Lei

    2013-01-01

    Visualization of the blood vessels can provide valuable morphological information for diagnosis and therapy strategies for cardiovascular disease. Intravascular ultrasound (IVUS) is able to delineate internal structures of vessel wall with fine spatial resolution. However, the developed IVUS is insufficient to identify the fibrous cap thickness and tissue composition of atherosclerotic lesions. Novel imaging strategies have been proposed, such as increasing the center frequency of ultrasound or using a modulated excitation technique to improve the accuracy of diagnosis. Dual-mode tomography combining IVUS with optical tomography has also been developed to determine tissue morphology and characteristics. The implementation of these new imaging methods requires an open system that allows users to customize the system for various studies. This paper presents the development of an IVUS system that has open structures to support various imaging strategies. The system design is based on electronic components and printed circuit board, and provides reconfigurable hardware implementation, programmable image processing algorithms, flexible imaging control, and raw RF data acquisition. In addition, the proposed IVUS system utilized a miniaturized ultrasound transducer constructed using PMN-PT single crystal for better piezoelectric constant and electromechanical coupling coefficient than traditional lead zirconate titanate (PZT) ceramics. Testing results showed that the IVUS system could offer a minimum detectable signal of 25 ?V, allowing a 51 dB dynamic range at 47 dB gain, with a frequency range from 20 to 80 MHz. Finally, phantom imaging, in vitro IVUS vessel imaging, and multimodality imaging with photoacoustics were conducted to demonstrate the performance of the open system. PMID:23143570

  9. DISTRIBUTED HYDROGEN FUELING SYSTEMS ANALYSIS

    Microsoft Academic Search

    John P. Reardon; Franklin D. Lomax; Jennifer Pinyan; Ira F. Kuhn

    2001-01-01

    Directed Technologies Inc. has analyzed the costs and other attributes of three fuel infrastructure systems to support fuel cell vehicles: hydrogen, methanol and gasoline. This work compliments previous DTI analyses of onboard fuel system costs for these three fuels B onboard hydrogen storage systems in the case of hydrogen, and onboard fuel processors for methanol and for gasoline. The results

  10. Modelling a Distributed Railway Control System

    E-print Network

    Modelling a Distributed Railway Control System Morten Skjoldborg Madsen & Martin Møller Bæk Master control system for a simple railway line. Control systems exist to ensure safety of trains by prevent- ing in the development. Keywords: formal specification, railway lines, control systems, JAVA, XML, simulation, safety

  11. THINK: a secure distributed systems architecture

    Microsoft Academic Search

    Christophe Rippert; Jean-bernard Stefani

    2002-01-01

    In this paper, we present THINK, our distributed systems architecture, and the research we have conducted to provide the system programmer with an architecture he can use to build efficient and secure operating systems. By specifying and implementing elementary tools that can be used by the system programmer to implement a chosen security policy, we prove that flexibility can be

  12. On deadlock detection in distributed systems

    NASA Technical Reports Server (NTRS)

    Gligor, V. D.; Shattuck, S. H.

    1980-01-01

    A hierarchically organized and a distributed protocol for deadlock detection in distributed databases are presented in a previous study Menasce and Muntz (1979). In this paper, it is shown that the distributed protocol is incorrect, and possible remedies are presented. However, the distributed protocol remains impractical because 'condensations' of 'transaction-wait-for' graphs make graph updates difficult to perform. Delayed graph updates cause the occurrence of false deadlocks in this as well as in some other deadlock detection protocols for distributed systems. The performance degradation that results from false deadlocks depends on the characteristics of each protocol.

  13. 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.

  14. 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.

  15. 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

  16. OCSEGen: Open Components and Systems Environment Generator

    NASA Technical Reports Server (NTRS)

    Tkachuk, Oksana

    2014-01-01

    To analyze a large system, one often needs to break it into smaller components.To analyze a component or unit under analysis, one needs to model its context of execution, called environment, which represents the components with which the unit interacts. Environment generation is a challenging problem, because the environment needs to be general enough to uncover unit errors, yet precise enough to make the analysis tractable. In this paper, we present a tool for automated environment generation for open components and systems. The tool, called OCSEGen, is implemented on top of the Soot framework. We present the tool's current support and discuss its possible future extensions.

  17. Frustration of Decoherence in Open Quantum Systems

    E-print Network

    E. Novais; A. H. Castro Neto; L. Borda; I. Affleck; G. Zarand

    2005-02-18

    We study a model of frustration of decoherence in an open quantum system. Contrary to other dissipative ohmic impurity models, such as the Kondo model or the dissipative two-level system, the impurity model discussed here never presents overdamped dynamics even for strong coupling to the environment. We show that this unusual effect has its origins in the quantum mechanical nature of the coupling between the quantum impurity and the environment. We study the problem using analytic and numerical renormalization group methods and obtain expressions for the frequency and temperature dependence of the impurity susceptibility in different regimes.

  18. Accounting and Accountability for Distributed and Grid Systems

    NASA Technical Reports Server (NTRS)

    Thigpen, William; McGinnis, Laura F.; Hacker, Thomas J.

    2001-01-01

    While the advent of distributed and grid computing systems will open new opportunities for scientific exploration, the reality of such implementations could prove to be a system administrator's nightmare. A lot of effort is being spent on identifying and resolving the obvious problems of security, scheduling, authentication and authorization. Lurking in the background, though, are the largely unaddressed issues of accountability and usage accounting: (1) mapping resource usage to resource users; (2) defining usage economies or methods for resource exchange; (3) describing implementation standards that minimize and compartmentalize the tasks required for a site to participate in a grid.

  19. Fluctuations of work in nearly adiabatically driven open quantum systems

    E-print Network

    S. Suomela; J. Salmilehto; I. G. Savenko; T. Ala-Nissila; M. Möttönen

    2015-03-27

    We extend the quantum jump method to nearly adiabatically driven open quantum systems in a way that allows for an accurate account of the external driving in the system-environment interaction. Using this framework, we construct the corresponding trajectory-dependent work performed on the system and derive the integral fluctuation theorem and the Jarzynski equality for nearly adiabatic driving. We show that such identities hold as long as the stochastic dynamics and work variable are consistently defined. We numerically study the emerging work statistics for a two-level quantum system and find that the conventional diabatic approximation is unable to capture some prominent features arising from driving such as the continuity of the probability density of work. Our results reveal the necessity of using accurate expressions for the drive-dressed heat exchange in future experiments probing jump time distributions.

  20. Fluctuations of work in nearly adiabatically driven open quantum systems

    NASA Astrophysics Data System (ADS)

    Suomela, S.; Salmilehto, J.; Savenko, I. G.; Ala-Nissila, T.; Möttönen, M.

    2015-02-01

    We extend the quantum jump method to nearly adiabatically driven open quantum systems in a way that allows for an accurate account of the external driving in the system-environment interaction. Using this framework, we construct the corresponding trajectory-dependent work performed on the system and derive the integral fluctuation theorem and the Jarzynski equality for nearly adiabatic driving. We show that such identities hold as long as the stochastic dynamics and work variable are consistently defined. We numerically study the emerging work statistics for a two-level quantum system and find that the conventional diabatic approximation is unable to capture some prominent features arising from driving, such as the continuity of the probability density of work. Our results reveal the necessity of using accurate expressions for the drive-dressed heat exchange in future experiments probing jump time distributions.

  1. Fluctuations of work in nearly adiabatically driven open quantum systems

    E-print Network

    S. Suomela; J. Salmilehto; I. G. Savenko; T. Ala-Nissila; M. Möttönen

    2014-11-18

    We extend the quantum jump method to nearly adiabatically driven open quantum systems in a way that allows for an accurate account of the external driving in the system-environment interaction. Using this framework, we construct the corresponding trajectory-dependent work performed on the system and derive the integral fluctuation theorem and the Jarzynski equality for nearly adiabatic driving. We show that such identities hold as long as the stochastic dynamics and work variable are consistently defined. We study the emerging work statistics for a two-level quantum system and find that the conventional diabatic approximation is unable to capture some prominent features arising from driving such as the continuity of the probability density of work. Our results reveal the necessity of using accurate expressions for the drive-dressed heat exchange in future experiments probing jump time distributions.

  2. 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.

  3. Grid Services for Distributed System Integration

    Microsoft Academic Search

    Ian T. Foster; Carl Kesselman; Jeffrey M. Nick; Steven Tuecke

    2002-01-01

    abstractions and concepts that let applications access and share resources and services across dis-tributed, wide area networks, while providing com-mon security semantics, distributed resource management performance, coordinated fail-over, problem determination services, or other QoS met-rics that are of importance in a particular context. For some time, such problems have been of cen-tral concern to developers of distributed systems for large-scale

  4. A Distributed Building Evacuation System

    E-print Network

    Qumsiyeh, Dany M.

    2008-07-14

    This thesis investigates the feasibility of a smart building evacuation system, capable of guiding occupants along safe paths to exits and responding to changing threats. Inspired by developments in amorphous computing, ...

  5. A distributed building evacuation system

    E-print Network

    Qumsiyeh, Dany M

    2008-01-01

    This thesis investigates the feasibility of a smart building evacuation system, capable of guiding occupants along safe paths to exits and responding to changing threats. Inspired by developments in amorphous computing, ...

  6. 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...

  7. The Mathematical Foundation of Distributed Interleaved Systems

    Microsoft Academic Search

    Shaul Ozeri; Doron Shmilovitz; Sigmond Singer; Luis Martinez-Salamero

    2007-01-01

    The distribution and interleaving (D&I) of signals is a common method for ripple attenuation in various engineering applications in such areas as control, communication, and power electronics. Similarities to this technique may also been found in nonengineering fields such as biology and medicine. This paper presents a mathematical exploration of distributed interleaved systems along with a simple frequency-domain model of

  8. System approach to distributed sensor management

    Microsoft Academic Search

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

    2010-01-01

    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

  9. 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,…

  10. A PILOT ENVIRONMENTAL DATA GRID DISTRIBUTION SYSTEM

    EPA Science Inventory

    The primary objectives of this study are to implement, operate, and evaluate a workable, distributed data access, format neutral "data-on-demand" prototype, leveraging leading-edge technologies assembled in a unique operational prototype system and distributed over the U.S. EPA's...

  11. Multicommodity Distribution System Design by Benders Decomposition

    Microsoft Academic Search

    A. M. Geoffrion; G. W. Graves

    1974-01-01

    A commonly occurring problem in distribution system design is the optimal location of intermediate distribution facilities between plants and customers. A multi-commodity capacitated single-period version of this problem is formulated as a mixed integer linear program. A solution technique based on Benders Decomposition is developed, implemented, and successfully applied to a real problem for a major food firm with 17

  12. Open Source assimilation tool for distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Richard, Julien; Giangola-Murzyn, Agathe; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2013-04-01

    An advanced GIS data assimilation interface is a requisite to obtain a distributed hydrological model that is both transportable from catchment to catchment and is easily adaptable to data resolution. This tool is achieved for the cartographic data as well as the linked information data. In the case of the Multi-Hydro-Version2 model (A. Giangola-Murzyn et al. 2012), several types of information are distributed on a regular grid. The grid cell size has to be chosen by the user and each cell has to be filled up with information. In order to be the most realistic as possible, the Multi-Hydro model takes into account several data. For that, the assimilation tool (MH-AssimTool) has to be able to import all these different information. The needed flexibility of the studied area and grid size requires that the GIS interface must be easy to take in hand and also practical. The solution of a main window for the geographical visualisation and hierarchical menus coupled with checkboxes was chosen. For example, the geographical information, like the topography or the land use can be visualized in the main window. For the other data, like the soil conductivity, the geology or the initial moisture, the information is demanded through several pop-up windows. Once the needed information imported, MH-AssimTool prepares automatically the data. For the topography data conversion, if the resolution is too small, an interpolation is done during the processing. As a result, all the converted data is in a good resolution for the modelling. As Multi-Hydro, MH-AssimTool is open source. It's coded in Visual Basic language coupled with a GIS library. The interface is built in such a way then it can be used by a non specialist. We will illustrate the efficiency of the tool with some case studies of peri-urban catchments of widely different sizes and characteristics. We will also explain some parts of the coding of the interface.

  13. Testing the SANCHO model on distribution systems

    Microsoft Academic Search

    Patrick Laurent; Pierre Servais; Michèle Prévost; Dominique Gatel; Bernard Clément

    1997-01-01

    Empirical findings were used to evaluate a deterministic model of bacterial dynamics in a pipe carrying potable water. The SANCHO model simulates the response of fixed and free bacteria in the system to the concentrations of chlorine and organic substrate entering the system. The authors tested the model on seven fullscale distribution systems and made a study of the error

  14. Network design consideration for distributed control systems

    Microsoft Academic Search

    Feng-Li Lian; James Moyne; Dawn Tilbury

    2002-01-01

    This paper discusses the impact of network architecture on control performance in a class of distributed control systems called networked control systems (NCSs) and provides design considerations related to control quality of performance as well as network quality of service. The integrated network-control system changes the characteristics of time delays between application devices. This study first identifies several key components

  15. Communication synthesis for distributed embedded systems

    Microsoft Academic Search

    Ross B. Ortega; Gaetano Borriello

    1998-01-01

    Designers of distributed embedded systems face many challenges in determining the appropriate tradeoffs to make when defining a system architecture or retargeting an existing design. Communica- tion synthesis, the automatic generation of the necessary software and hardware needed for system components to exchange data, is required to more effectively explore the design space and automate what are very error-prone tasks.

  16. A DISTRIBUTED AUTOMATION SYSTEM FOR ELECTROPHYSICAL INSTALLATIONS

    E-print Network

    Kozak, Victor R.

    A DISTRIBUTED AUTOMATION SYSTEM FOR ELECTROPHYSICAL INSTALLATIONS V.R. Kozak Budker Institute There was designed a set of devices for automation systems of physical installations. On this basis approach. KEY WORDS Automation, systems, applications, CANBUS, embedded, controller. 1. Introduction Budker

  17. Preemptive Scheduling for Distributed Systems 1

    Microsoft Academic Search

    Partha Dasgupta; Donald Mclaughlin; Shantanu Sardesai

    Preemptive scheduling is widespread in operating systems and in parallel processing on symmetric multiprocessors. However, in dis- tributed systems it is practically unheard of. Scheduling in distributed systems is an important issue, and has performance impact on parallel processing, load balancing and metacomputing. Non-preemptive scheduling can perform well if the task lengths and processor speeds are known in advance and

  18. Convex Models of Distribution System Reconfiguration

    E-print Network

    Taylor, Joshua A.

    We derive new mixed-integer quadratic, quadratically constrained, and second-order cone programming models of distribution system reconfiguration, which are to date the first formulations of the ac problem that have convex, ...

  19. Automated Fault Location In Smart Distribution Systems

    E-print Network

    Lotfifard, Saeed

    2012-10-19

    Fault location in distribution systems is a critical component of outage management and service restoration, which directly impacts feeder reliability and quality of the electricity supply. Improving fault location methods supports the Department...

  20. The open source, object- and process oriented simulation system OpenGeoSys - concepts, development, community

    NASA Astrophysics Data System (ADS)

    Bauer, S.; Li, D.; Beyer, C.; Wang, W.; Bilke, L.; Graupner, B.

    2011-12-01

    Many geoscientific problems, such as underground waste disposal, nuclear waste disposal, CO2 sequestration, geothermal energy, etc., require for prediction of ongoing processes as well as risk and safety assessment a numerical simulation system. The governing processes are thermal heat transfer (T), hydraulic flow in multi-phase systems (H), mechanical deformation (M) and geochemical reactions (C), which interact in a complex way (THMC). The development of suitable simulation systems requires a large amount of effort for code development, verification and applications. OpenGeoSys (OGS) is an open source scientific initiative for the simulation of these THMC processes in porous media. A flexible numerical framework based on the Finite Element Method is provided and applied to the governing process equations. Due to the object- and process-oriented character of the code, functionality enhancement and code coupling with external simulators can be performed reasonably effectively. This structure also allows for a distributed development, with developers at different locations contributing to the common code. The code is platform independent, accessible via internet for development and application, and checked by an automated benchmarking system regularly.

  1. On the relationship between open cellular convective cloud patterns and the spatial distribution of precipitation

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.; Feingold, G.

    2015-02-01

    Precipitation is thought to be a necessary but insufficient condition for the transformation of stratocumulus-topped closed cellular convection to open cellular cumuliform convection. Here we test the hypothesis that the spatial distribution of precipitation is a key element of the closed-to-open cell transition. A series of idealized 3-D simulations are conducted to evaluate the dependency of the transformation on the areal coverage of rain, and to explore the role of interactions between multiple rainy areas in the formation of the open cells. When rain is restricted to a small area, even substantial rain (order few mm day-1) does not result in a transition. With increasing areal coverage of the rain, the transition becomes possible provided that the rain rate is sufficiently large. When multiple small rain regions interact with each other, the transition occurs and spreads over a wider area, provided that the distance between the rain regions is short. When the distance between the rain areas is large, the transition eventually occurs, albeit slowly. For much longer distances between rain regions the system is anticipated to remain in a closed-cell state. These results suggest a connection to the recently hypothesized remote control of open-cell formation. Finally it is shown that this transition occurs along a consistent path in the phase space of the mean vs. coefficient of variation of the liquid water path, droplet number and optical depth. This could be used as a diagnostic tool for global analyses of the statistics of closed- and open-cell occurrence and transitions between them.

  2. A distributed data component for the open modeling interface

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the volume of collected data continues to increase in the environmental sciences, so does the need for effective means for accessing those data. We have developed an Open Modeling Interface (OpenMI) data component that retrieves input data for model components from environmental information syste...

  3. Distributed Architectures for Event-Based Systems

    Microsoft Academic Search

    Valentin Cristea; Florin Pop; Ciprian Dobre; Alexandru Costan

    \\u000a Event-driven distributed systems have two important characteristics, which differentiate them from other system types: the\\u000a existence of several software or hardware components that run simultaneously on different inter-networked nodes, and the use\\u000a of events as the main vehicle to organize component intercommunication. Clearly, both attributes influence event-driven distributed\\u000a architectures, which are discussed in this chapter. We start with presenting the

  4. 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.

  5. DCBITS: Distributed Case Base Intelligent Tutoring System

    NASA Astrophysics Data System (ADS)

    Rishi, O. P.; Govil, Rekha

    2008-05-01

    Online learning with Intelligent Tutoring System (ITS) is becoming very popular where the system models the student's learning behavior and presents to the student the learning material (content, questions-answers, assignments) accordingly. In today's distributed computing environment, the tutoring system can take advantage of networking to utilize the model for a student for students from other similar groups. In the present paper we present a methodology where using Case Based Reasoning (CBR), ITS provides student modeling for online learning in a distributed environment with the help of agents. Student modeling is a key component in any Intelligent Tutoring System (ITS). In today's distributed computing environment, the tutoring system can take advantage of networking to utilize the model for a student for students from other similar group. In the present paper we present a methodology where using Case Based Reasoning (CBR), the ITS provides student modeling for online learning in a distributed environment with the help of agents. The Chapter describes the approach, the architecture, and the agent characteristics for the student modeling in the ITS. This concept can be deployed to develop ITS where the tutor can author and the students can learn locally whereas the ITS can model the students' learning globally in a distributed environment. The advantage of such an approach is that both the learning material (domain knowledge) and students' model can be globally distributed thus enhancing the efficiency of ITS with reducing the bandwidth requirement and complexity of the system.

  6. 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

  7. 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.

  8. 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.

  9. Studying distribution system reliability against lightning

    SciTech Connect

    Romualdo, C.; Brito, F.; Perez, H.; De la Rosa, F.; Sarmiento, H.G.

    1989-01-01

    In this article, the authors present a general overview of the use of computers in different areas of a research project intended to study the adequate protection of distribution systems against lightning. First, the effects of lightning on electric power distribution will be presented; then, a discussion on the modeling of lightning phenomena and other areas that are needed to perform analytical studies to predict distribution system reliability against lightning will be given. Subsequently, a brief description will be given of field measurements of ground flash density and lightning location. Finally, we will enumerate areas that have been identified as requiring further research.

  10. Lightning protection of distribution systems. Final report

    SciTech Connect

    Uman, M.A.

    1985-02-01

    Analyses are presented of experimental data obtained in the Tampa Bay area during 1978 and 1979 concerning the physical and phenomenological properties of lightning and the interaction of that lightning with the local distribution power systems. Specific results are given regarding: (1) the physical and phenomenology properties of lightning in the Tampa Bay area and its relation to lightning elsewhere; (2) measurement and theory concerning lightning-induced voltages on distribution lines; (3) distribution system operation in the presence of lightning and analytical modeling and prediction of that operation.

  11. Assurance System Architecture for Distributed Database Systems

    Microsoft Academic Search

    Carlos Perez Leguizamo; Aqeel A. Syed; Kinji Mori

    2002-01-01

    Recently with the advent of the information technology and the wide spread use of the Internet, new user oriented production and logistic systems, such as the supply chain management system, have been required in order to cope with the drastic and continuous changes on the markets and users' preferences. To achieve this purpose, the companies need to mutually integrate their

  12. 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.

  13. Bluetooth-based distributed measurement system

    NASA Astrophysics Data System (ADS)

    Tang, Baoping; Chen, Zhuo; Wei, Yuguo; Qin, Xiaofeng

    2007-07-01

    A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

  14. 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.

  15. A reliability assessment methodology for distribution systems with distributed generation

    E-print Network

    Duttagupta, Suchismita Sujaya

    2006-08-16

    and forced outage of the WTG. A two-state model represented other components of the distribution system such as transformers etc. The authors [5] noted the reliability impact on an individual load point to be dependent on the location of the load point...; Bus 2 RBTS and Bus 4 RBTS networks described in chapter IV. Different magnitudes of system supply constitutes each case. Within each case, the orginal network?s reliability is compared with the networks when DG is added to them. A total of eighteen...

  16. 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.

  17. 78 FR 79298 - Securities Exempted; Distribution of Shares by Registered Open-End Management Investment Company...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ...33-9503; IC-30845] Securities Exempted; Distribution...Registered Open- End Management Investment Company...Profit-Sharing Plans AGENCY: Securities and Exchange Commission...Division of Investment Management, U.S. Securities and Exchange...

  18. Onsite Wastewater Treatment Systems: Spray Distribution System

    E-print Network

    Lesikar, Bruce J.

    2008-10-23

    it working To perform well, spray systems require proper operation and main- tenance. They must clean the waste- water to a secondary-quality effluent. Check the operation and mainte- nance requirements for your par- ticular type of treatment system... re- ? moves pathogens (disease-caus- ing organisms) from the waste- water. Chlorination is the most common disinfection method; A pump tank, which collects and ? holds the water until it is sprayed over the landscape; and Spray heads, which...

  19. 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.

  20. A Distributed System Architecture For Embedded Control Systems

    Microsoft Academic Search

    Gianfranco Ciccarella; F. Patricelli

    1994-01-01

    ribes a distributed system architecture based on nodes (N-cube modules) connected by a Local Area Network. The system has been developed to support the implementation of new services in a B-ISDN testbed and, in general, to provide a suitable solution to many design problems of computing system for control applications. A distributed operating system, designed by an object-model approach, supports

  1. An Embedded Future for Distributed System Architectures

    Microsoft Academic Search

    Trygve Lunheim; Amund Skavhaug

    Recent advances in distributed system architectures may provide the solution to a number of challenges in future embedded systems. Middleware and grid technologies make it possible to utilize the processing power in subsystems, so that greater reliability through fault-tolerance can be achieved, as well as efficient use of resources through load-sharing. In this paper we try to revisit and reassess

  2. Data Integration in Computer Distributed Systems

    NASA Astrophysics Data System (ADS)

    Kwiecie?, B?a?ej

    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.

  3. 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.

  4. Quality of Service in Heterogeneous Distributed Systems

    Microsoft Academic Search

    Christophe Diotl; Aruna Seneviratne

    1997-01-01

    The future distributed systems will be very heterogeneous. They will consist of end computing systems with widely varying capabilities, interconnected by networks which offer very different services. Delivering data with a guaranted level of service is a real problem that requires both support at the network level (integrated services networks) and a QoS (Quality of Service) management environment. This paper

  5. JAVA Agents for Distributed System Management

    Microsoft Academic Search

    Christopher Brooks; Brian Tierney; William Johnston

    1998-01-01

    Wide-area distributed systems provide significant benefits in terms of parallelism, robustness and accessibility. However, they also present a new challenges in terms of configuration, maintenance and monitoring. A semi-autonomous management mechanism is needed to deal with systems that have lost contact with central administrators or have to deal with problems on time scales not possible by human administrators. In this

  6. Monitoring Delayed Systems with Spatial Distribution in

    E-print Network

    Brennan, Sean

    at the Intelligent Vehicles and Systems group at the Pennsylvania State University and the chair of mechatronics at theMonitoring Delayed Systems with Spatial Distribution in Presence of Realtime Requirements Synchronization and Prediction Bachelor Thesis by Jan Maximilian Montenbruck University Park, PA, January 2011

  7. Web Based Distributed Marine Education System

    Microsoft Academic Search

    Yang Xiao; Jin Yicheng

    2008-01-01

    This paper presents a Web based distributed marine education system. This system allow more users pursue training from anywhere and at anytime, via a PC and Web browser. It integrates the simulation to effectively makes up the limitation of traditional e-Learning, in which students tend to be restricted to a predetermined learning path through reading, listening and observation. We present

  8. Understanding fault-tolerant distributed systems

    Microsoft Academic Search

    Flavin Cristian

    1991-01-01

    We propose a small number of basic concepts that can be used to explain thearchitecture of fault-tolerant distributed systems and we discuss a list of architecturalissues that we find useful to consider when designing or examining suchsystems. For each issue we present known solutions and design alternatives, wediscuss their relative merits and we give examples of systems which adopt oneapproach

  9. Distributed Control System for Cogenerative Power Plants

    Microsoft Academic Search

    F. Hartescu; I. Miciu

    The paper presents a distributed control system for the realization of cogenerative supply of electricity and heat and, in given case, for their combination with waste heat recovery, particularly in combined (gas-steam) cycle industrial power plants. Modern electric power plants are large complex systems with many processes whose operations need to be optimized. The electrical networks are designed for transmission,

  10. Situation aware computing in distributed computing systems

    Microsoft Academic Search

    Jurgo Preden; Johannes Helander

    2007-01-01

    Cyber-physical systems - distributed computing sys tems that combine computer networks with embedded devices interacting with the physical world are gaining importance and the need for such systems is growing. Significant advances have been made in programming large numbers of communicating tiny computers, such as sensor networks, in the past decade, however the progress has not been as fast as

  11. Experiences with the Amoeba distributed operating system

    Microsoft Academic Search

    Andrew S. Tanenbaum; Robbert van Renesse; Hans van Staveren; Gregory J. Sharp; Sape J. Mullender; Jack Jansen; Rossum van Guido

    1990-01-01

    The Amoeba project is a research effort aimed at understanding how to connect multiple computers in a seamless way [16, 17, 26, 27, 31]. The basic idea is to provide the users with the illusion of a single powerful timesharing system, when, in fact, the system is implemented on a collection of machines, potentially distributed among several countries. This research

  12. Detection of Mutual Inconsistency in Distributed Systems

    Microsoft Academic Search

    Douglas Stott Parker Jr.; Gerald J. Popek; Gerard Rudisin; Allen Stoughton; Bruce J. Walker; Evelyn Walton; Johanna M. Chow; David A. Edwards; Stephen Kiser; Charles S. Kline

    1983-01-01

    Many distributed systems are now being developed to provide users with convenient access to data via some kind of communications network. In many cases it is desirable to keep the system functioning even when it is partitioned by network failures. A serious problem in this context is how one can support redundant copies of resources such as files (for the

  13. Policy Driven Management for Distributed Systems

    Microsoft Academic Search

    Morris Sloman

    1994-01-01

    Separating management policy from the automated managers which interpret the policy facilitates the dynamic change of behaviour of a distributed management system. This permits it to adapt to evolutionary changes in the system being managed and to new application requirements. Changing the behaviour of automated managers can be achieved by changing the policy without have to reimplement them - this

  14. A remote monitoring system for Open Ocean Aquaculture

    Microsoft Academic Search

    A. P. M. Michel; K. L. Croff; K. W. McLetchie; J. D. Irish

    2002-01-01

    The purpose of this project was to determine the practicality and characteristics of a remote monitoring system for an open ocean aquaculture fish cage. The Open Ocean Aquaculture program at the University of New Hampshire currently uses two fish cages to develop the technology and methodology to raise finned fish in the open ocean. The cages are located about six

  15. Feshbach projection formalism for open quantum systems.

    PubMed

    Chru?ci?ski, Dariusz; Kossakowski, Andrzej

    2013-08-01

    We provide a new approach to open quantum systems which is based on the Feshbach projection method. Instead of looking for a master equation for the dynamical map acting in the space of density operators we provide the corresponding equation for the evolution in the Hilbert space of the amplitude operators. Its solution enables one to construct a legitimate quantum evolution (completely positive and trace preserving). Our approach, contrary to the standard Nakajima-Zwanzig method, allows for a series of consistent approximations resulting in a legitimate quantum evolution. The new scheme is illustrated by the well-known spin-boson model beyond the rotating wave approximation. It is shown that the presence of counterrotating terms dramatically changes the asymptotic evolution of the system. PMID:23952370

  16. Oblique color vision in an open-habitat bird: spectral sensitivity, photoreceptor distribution and behavioral implications.

    PubMed

    Moore, Bret A; Baumhardt, Patrice; Doppler, Megan; Randolet, Jacquelyn; Blackwell, Bradley F; DeVault, Travis L; Loew, Ellis R; Fernández-Juricic, Esteban

    2012-10-01

    Color vision is not uniform across the retina because of differences in photoreceptor density and distribution. Retinal areas with a high density of cone photoreceptors may overlap with those with a high density of ganglion cells, increasing hue discrimination. However, there are some exceptions to this cell distribution pattern, particularly in species with horizontal visual streaks (bands of high ganglion cell density across the retina) that live in open habitats. We studied the spectral sensitivity and distribution of cone photoreceptors involved in chromatic and achromatic vision in the Canada goose (Branta canadiensis), which possesses an oblique rather than horizontal visual streak at the ganglion cell layer. Using microspectrophotometry, we found that the Canada goose has a violet-sensitive visual system with four visual pigments with absorbance peaks at 409, 458, 509 and 580 nm. The density of most cones involved in chromatic and achromatic vision peaked along a band across the retina that matched the oblique orientation of the visual streak. With the information on visual sensitivity, we calculated chromatic and achromatic contrasts of different goose plumage regions. The regions with the highest visual saliency (cheek, crown, neck and upper tail coverts) were the ones involved in visual displays to maintain flock cohesion. The Canada goose oblique visual streak is the retinal center for chromatic and achromatic vision, allowing individuals to sample the sky and the ground simultaneously or the horizon depending on head position. Overall, our results show that the Canada goose visual system has features that make it rather different from that of other vertebrates living in open habitats. PMID:22956248

  17. Open Giant Intelligent Information Systems and Its Multiagent-Oriented System Design

    E-print Network

    Cao, Longbing

    is actually a human-computer-cooperated intelligent information system[2,3]. As for how to build an open giant of an MAS. Among all system complexities of open giant intelligent information system, society and humanOpen Giant Intelligent Information Systems and Its Multiagent-Oriented System Design Longbing Cao

  18. Tsallis Entropy Based Velocity Distribution in Open Channel Flows

    E-print Network

    Luo, Hao

    2010-07-14

    entropy based 2-D velocity distribution, Eq. (41) plotted against experimental data for Run 16 by Coleman (1986) ....................................................................................... 71 23 Relationship of parameter...(Data from Run 12, Coleman, 1986) ........................ 135 49 Comparison of Tsallis entropy-based velocity distribution with observed velocity and velocity distributions based on Shannon entropy and Prandtl-von Karman universal velocity...

  19. 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.

  20. Distributed Storage Systems for Data Intensive Computing

    SciTech Connect

    Vazhkudai, Sudharshan S [ORNL; Butt, Ali R [Virginia Polytechnic Institute and State University (Virginia Tech); Ma, Xiaosong [ORNL

    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.

  1. 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.

  2. On-Site Wastewater Treatment Systems: Spray Distribution

    E-print Network

    Lesikar, Bruce J.

    1999-09-06

    A spray distribution system is very similar to a lawn irrigation system. Spray heads are used to distribute treated wastewater to the surface of the yard. This publication explains the advantages and disadvantages of spray distribution systems...

  3. Cost Modeling and Design Techniques for Integrated Package Distribution Systems

    E-print Network

    Daganzo, Carlos F.

    Cost Modeling and Design Techniques for Integrated Package Distribution Systems Karen R. Smilowitz and Carlos F. Daganzo June 27, 2002 Abstract Complex package distribution systems are designed using and operation of integrated package distribution systems. Qualitative conclusions suggest that benefits

  4. A system for distributed intrusion detection

    Microsoft Academic Search

    S. R. Snapp; James Brentano; Gihan V. Dias; Terrance L. Goan; Tim Grance; L. Todd Heberlein; Che-Lin Ho; Karl N. Levitt; Biswanath Mukherjee; Douglass L. Mansur; Kenneth L. Pon; S. E. Smaha

    1991-01-01

    The network intrusion-detection concept is extended from the LAN (local area network) environment to arbitrarily 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. The proposed architecture for this distributed intrusion-detection system consists

  5. Multicommodity Distribution System Design by Benders Decomposition * † ‡

    Microsoft Academic Search

    A. M. Geoffrion

    \\u000a A commonly occurring problem in distribution system design is the optimal location of intermediate distribution facilities\\u000a between plants and customers. A multicommodity capacitated single-period version of this problem is formulated as a mixed\\u000a integer linear program. A solution technique based on Benders Decomposition is developed, implemented, and successfully applied\\u000a to a real problem for a major food firm with 17

  6. Research of real time embedded distributed systems

    Microsoft Academic Search

    Huang Guang Jun; Petr Musilek

    2008-01-01

    Real time embedded systems have to use relatively simple scheduling models and algorithms because of their constrained resource. In this paper, a kind of real-time distributed system architecture is presented. The system consists of a two-stages scheduling strategy, overload scheduling algorithm based on a multi-priorities, a improved real time scheduling algorithm based on preemption threshold, a priority driving Ethernet protocol

  7. Neutral particle beam distributed data acquisition system

    SciTech Connect

    Daly, R.T.; Kraimer, M.R.; Novick, A.H.

    1987-01-01

    A distributed data acquisition system has been designed to support experiments at the Argonne Neutral Particle Beam Accelerator. The system uses a host VAXstation II/GPX computer acting as an experimenter's station linked via Ethernet with multiple MicroVAX IIs and rtVAXs dedicated to acquiring data and controlling hardware at remote sites. This paper describes the hardware design of the system, the applications support software on the host and target computers, and the real-time performance.

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

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

  9. Quantum and statistical mechanics in open systems: theory and examples

    NASA Astrophysics Data System (ADS)

    Zueco, David

    2009-08-01

    Using the system-bath model Hamiltonian this thesis covers the equilibrium and out of equilibrium properties of quantum open systems. Topics included are the calculation of thermodynamical quantities of open systems, derivation of quantum master equations, phase space and numerical methods and Linear and non Linear Response Theory. Applications are the transport in periodic potentials and the dynamics of spins.

  10. Measurements over distributed high performance computing and storage systems

    NASA Technical Reports Server (NTRS)

    Williams, Elizabeth; Myers, Tom

    1993-01-01

    Requirements are carefully described in descriptions of systems to be acquired but often there is no requirement to provide measurements and performance monitoring to ensure that requirements are met over the long term after acceptance. A set of measurements for various UNIX-based systems will be available at the 1992 Goddard Conference on Mass Storage Systems and Technologies. The authors invite others to contribute to the set of measurements. The framework for presenting the measurements of supercomputers, workstations, file servers, mass storage systems, and the networks that interconnect them are given. Production control and database systems are also included. Though other applications and third party software systems are not addressed, it is important to measure them as well. The capability to integrate measurements from all these components from different vendors, and from the third party software systems was recognized and there are efforts to standardize a framework to do this. The measurement activity falls into the domain of management standards. Standards work is ongoing for Open Systems Interconnection (OSI) systems management; AT&T, Digital, and Hewlett-Packard are developing management systems based on this architecture even though it is not finished. Another effort is in the UNIX International Performance Management Working Group. In addition, there are the Open Systems Foundation's Distributed Management Environment and the Object Management Group. A paper comparing the OSI systems management model and the Object Management Group model has been written. The IBM world has had a capability for measurement for various IBM systems since the 1970's and different vendors were able to develop tools for analyzing and viewing these measurements. Since IBM was the only vendor, the user groups were able to lobby IBM for the kinds of measurements needed. In the UNIX world of multiple vendors, a common set of measurements will not be as easy to get.

  11. The ATLAS Distributed Data Management System & Databases

    E-print Network

    Garonne, V; The ATLAS collaboration; Barisits, M; Beermann, T; Vigne, R; Serfon, C

    2013-01-01

    The ATLAS Distributed Data Management (DDM) System is responsible for the global management of petabytes of high energy physics data. The current system, DQ2, has a critical dependency on Relational Database Management Systems (RDBMS), like Oracle. RDBMS are well-suited to enforcing data integrity in online transaction processing applications, however, concerns have been raised about the scalability of its data warehouse-like workload. In particular, analysis of archived data or aggregation of transactional data for summary purposes is problematic. Therefore, we have evaluated new approaches to handle vast amounts of data. We have investigated a class of database technologies commonly referred to as NoSQL databases. This includes distributed filesystems, like HDFS, that support parallel execution of computational tasks on distributed data, as well as schema-less approaches via key-value stores, like HBase. In this talk we will describe our use cases in ATLAS, share our experiences with various databases used ...

  12. 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.

  13. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... false Distribution systems: Leakage surveys. 192.723 Section 192.723 Transportation Other Regulations Relating...MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.723 Distribution systems: Leakage...

  14. Quantum response of dephasing open systems

    NASA Astrophysics Data System (ADS)

    Avron, J. E.; Fraas, M.; Graf, G. M.; Kenneth, O.

    2011-05-01

    We develop a theory of adiabatic response for open systems governed by Lindblad evolutions. The theory determines the dependence of the response coefficients on the dephasing rates and allows for residual dissipation even when the ground state is protected by a spectral gap. We give the quantum response a geometric interpretation in terms of Hilbert space projections: for a two-level system and, more generally, for systems with a suitable functional form of the dephasing, the dissipative and non-dissipative parts of the response are linked to a metric and to a symplectic form. The metric is the Fubini-Study metric and the symplectic form is the adiabatic curvature. When the metric and symplectic structures are compatible, the non-dissipative part of the inverse matrix of response coefficients turns out to be immune to dephasing. We give three examples of physical systems whose quantum states induce compatible metric and symplectic structures on control space: qubit, coherent states and a model of the integer quantum Hall effect.

  15. A Novel Framework for Building Distributed Data Acquisition and Monitoring Systems

    Microsoft Academic Search

    Vu Van Tan; Dae-seung Yoo; Myeong-jae Yi

    2007-01-01

    We propose a novel framework for building a distributed data acquisition and monitoring system. Our novel framework is mainly based on XML leverages and OPC (Openness, Productivity, and Connectivity) techni- ques. Correspondingly, our framework-based system allows easily aggregating more than the hundreds or thousands of the existing OPC DA (Data Access) products in use today with new OPC XML-DA products

  16. How open should an open system be? : essays on mobile computing

    E-print Network

    Boudreau, Kevin J. (Kevin Joseph)

    2006-01-01

    "Systems" goods-such as computers, telecom networks, and automobiles-are made up of multiple components. This dissertation comprises three essays that study the decisions of system innovators in mobile computing to "open" ...

  17. QuTiP: An open-source Python framework for the dynamics of open quantum systems

    NASA Astrophysics Data System (ADS)

    Johansson, J. R.; Nation, P. D.; Nori, Franco

    2012-08-01

    We present an object-oriented open-source framework for solving the dynamics of open quantum systems written in Python. Arbitrary Hamiltonians, including time-dependent systems, may be built up from operators and states defined by a quantum object class, and then passed on to a choice of master equation or Monte Carlo solvers. We give an overview of the basic structure for the framework before detailing the numerical simulation of open system dynamics. Several examples are given to illustrate the build up to a complete calculation. Finally, we measure the performance of our library against that of current implementations. The framework described here is particularly well suited to the fields of quantum optics, superconducting circuit devices, nanomechanics, and trapped ions, while also being ideal for use in classroom instruction. Catalogue identifier: AEMB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 16 482 No. of bytes in distributed program, including test data, etc.: 213 438 Distribution format: tar.gz Programming language: Python Computer: i386, x86-64 Operating system: Linux, Mac OSX, Windows RAM: 2+ Gigabytes Classification: 7 External routines: NumPy (http://numpy.scipy.org/), SciPy (http://www.scipy.org/), Matplotlib (http://matplotlib.sourceforge.net/) Nature of problem: Dynamics of open quantum systems. Solution method: Numerical solutions to Lindblad master equation or Monte Carlo wave function method. Restrictions: Problems must meet the criteria for using the master equation in Lindblad form. Running time: A few seconds up to several tens of minutes, depending on size of underlying Hilbert space.

  18. 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.

  19. Test Tube Distributed Systems Based on Splicing

    Microsoft Academic Search

    Erzsébet Csuhaj-varjú; Lila Kari; Gheorghe Paun

    1996-01-01

    . We define a symbol processing mechanism with the components(test tubes) working as splicing schemes in the sense of T.Head and communicating by redistributing the contents of tubes (ina similar way to the separate operation of Lipton-Adleman). (Thesesystems are similar to the distributed generative mechanisms calledParallel Communicating Grammar Systems.) Systems with finiteinitial contents of tubes and finite sets of splicing

  20. Programming model for distributed intelligent systems

    NASA Technical Reports Server (NTRS)

    Sztipanovits, J.; Biegl, C.; Karsai, G.; Bogunovic, N.; Purves, B.; Williams, R.; Christiansen, T.

    1988-01-01

    A programming model and architecture which was developed for the design and implementation of complex, heterogeneous measurement and control systems is described. The Multigraph Architecture integrates artificial intelligence techniques with conventional software technologies, offers a unified framework for distributed and shared memory based parallel computational models and supports multiple programming paradigms. The system can be implemented on different hardware architectures and can be adapted to strongly different applications.

  1. High impedance fault detection on distribution systems

    Microsoft Academic Search

    C. G. Wester

    1998-01-01

    The detection of high impedance faults on electrical distribution systems has been one of the most persistent and difficult problems facing the electric utility industry. Recent advances in digital technology have enabled practical solutions for the detection of a high percentage of these previously undetectable faults. This paper reviews several mechanical and electrical methods of detecting high impedance faults. The

  2. Supervisory Control of Distributed Systems: Conflict Resolution

    Microsoft Academic Search

    K. C. Wong; J. G. Thistle; Roland P. Malhamé; Hai Hoc Hoang

    2000-01-01

    In distributed synthesis and control, one well-known potential hazard is conflict between modular designs. In a modular approach to the supervisory control of discrete-event systems, modular supervisors that are individually nonblocking (with respect to the plant) may nevertheless conflict and thus produce blocking, or even deadlock, when operating concurrently. A scheme of resolving this potential conflict between the modular supervisors

  3. Security architecture for heterogeneous distributed computing systems

    Microsoft Academic Search

    Syed Naqvi; Michel Riguidel

    2004-01-01

    Distributed systems face a proliferation of users, applications, networked devices, and their interactions on a scale never experienced before. The advent of reliable spontaneous networking technologies has ostensibly raised the stakes for the design of computing intensive environments using intelligent devices. As environmental intelligence grows, so will the number of heterogeneous devices connected to the environment. The creation of security

  4. Distributed Neural Systems for Face Perception

    E-print Network

    Bucci, David J.

    Chapter 6 Distributed Neural Systems for Face Perception James V. Haxby and Maria Ida Gobbini Introduction Face perception plays a central role in social communication and is, arguably, one of the most sophisticated visual perceptual skills in humans. Consequently, face perception has been the sub- ject

  5. Process Partitioning for Distributed Embedded Systems

    Microsoft Academic Search

    Junwei Hou; Wayne Wolf

    1996-01-01

    We present a new technique for partitioning processes in distributed embedded systems. Our heuristic algorithm minimizes both context switch and communication overhead under real-time deadline and process size constraints; it also tries to allocate functions to processors which are well-suited to that function. The algorithm analyzes the sensitivity of the latency of the task graph to changes in vertices hierarchical

  6. Sheaves, Objects and Distributed Systems Grant Malcolm

    E-print Network

    Malcolm, Grant

    Sheaves, Objects and Distributed Systems Grant Malcolm Department of Computer Science University of a partially ordered set P For example, if P is a monoid, the prefix order is x y iff xz = y for some z, if P is a monoid, the prefix order is x y iff xz = y for some z; then (P) is the set of traces. #12

  7. 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...

  8. Biofilm accumulation in drinking water distribution systems

    Microsoft Academic Search

    J. C. Block; K. Haudidier; J. L. Paquin; J. Miazga; Y. Levi

    1993-01-01

    In order to classify the relative importance of the parameters governing the accumulation of biofilm in drinking water distribution systems, a study has been carried out, using an industrial pilot plant fed with finished waters, with three main objectives, viz. (i) determination of biofilm density on pipe surfaces (PVC or cement lined cast iron) as a function of the distance

  9. DISTRIBUTION SYSTEM RELIABILITY ANALYSIS USING A MICROCOMPUTER

    EPA Science Inventory

    Distribution system reliability for most utilities is maintained by the knowledge of a few key personnel. Generally, these water maintenance personnel use a good memory, repair records, a large wall map and a hydraulic model of the larger transmission mains to help identify probl...

  10. Transient flow in water distribution system

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk Jae

    Transient flow in a piping network was studied using both experimental and computer models. In the present study, three different numerical methods, the method of characteristics, the two-dimensional method, and the implicit method, are presented and discussed. Experiments for transient flow in a piping system has also been conducted to verify the computer model. The method of characteristics was developed using two traditional governing equations namely the continuity and the dynamic equation. The two-dimensional method was developed using cylindrical coordinates with transient computation employing an explicit scheme. Logarithmic velocity profiles are used in the cross section of a pipe and the hydraulic head as a function of space and time are computed. The implicit method was also developed using the same governing equations as that used in the method of characteristics with the implicit scheme for the finite difference analysis. Experimental investigations were conducted in order to measure the pressure time history for transient flow. Both frictional head loss and various minor losses in the piping system were measured experimentally. The equivalent head loss coefficient C L has been introduced in this study for both the method of characteristics and the implicit method. After conducting several experiments, the equivalent head loss coefficient CL for the experimental piping system in the present study was determined. All of the numerical methods were compared with the experimental data. The results of different methods of computation developed in the present study agree well with the experimental data. Six cases of numerical simulation for transient flow in distribution system were considered to demonstrate the transient effects in a distribution system. These cases are the simple looped network, small city model, small city model with backflow prevention assembly, small city with surge tank, medium sized city model, and the large sized city model. Each case was simulated with specified scenarios. The numerical methods developed in this study have been found to be a promising simulation tools for the solution of transient flow in a distribution system. These numerical methods can be used for the design of distribution system subject to transient flow. Moreover, it can be used as operational tools to protect the distribution system from the excessively high pressure, column separation due to excessive negative pressure, or any undesirable incidents in a distribution system.

  11. Skeletal anchorage system for open-bite correction

    Microsoft Academic Search

    Mikako Umemori; Junji Sugawara; Hideo Mitani; Hiroshi Nagasaka; Hiroshi Kawamura

    1999-01-01

    A skeletal anchorage system was developed for tooth movements. It consists of a titanium miniplate that is temporarily implanted in the maxilla or the mandible as an immobile anchorage. In this article, we introduce the skeletal anchorage system to intrude the lower molars in open-bite malocclusion and evaluate the results of treatment in two severe open-bite cases that underwent orthodontic

  12. Open MultiAgent Systems: Agent Communication and Integration

    E-print Network

    Utrecht, Universiteit

    have been proposed that facilitate the communication process in a multi­agent system. These agentsOpen Multi­Agent Systems: Agent Communication and Integration Rogier M. van Eijk, Frank S. de Boer is on the issues of agent communication and integration. We define an abstract programming lan­ guage for open

  13. USER-FRIENDLY, OPEN-SYSTEM SOFTWARE FOR TEACHING PROTECTIVE

    E-print Network

    1 USER-FRIENDLY, OPEN-SYSTEM SOFTWARE FOR TEACHING PROTECTIVE RELAYING APPLICATION AND DESIGN was on implementing user-friendly and open-system solution that will allow an easy use and straight-forward future as the common framework [1]. To be efficient, such a framework needs to be user-friendly and amenable to future

  14. Architecture of an Open Object-Oriented Database Management System

    Microsoft Academic Search

    David L. Wells; José A. Blakeley; Craig W. Thompson

    1992-01-01

    The architecture of the open object-oriented database (OODB) management system, its requirements, and its computational model, which builds database functionality as an extensible collection of transparent extensions to existing programming languages, are described. The way in which open OODB's system architecture is decomposed into a kernal meta-architecture and a collection of modules implementing specific behavioral extensions is discussed. The potential

  15. Empowering open systems through cross-platform interoperability

    NASA Astrophysics Data System (ADS)

    Lyke, James C.

    2014-06-01

    Most of the motivations for open systems lie in the expectation of interoperability, sometimes referred to as "plug-and-play". Nothing in the notion of "open-ness", however, guarantees this outcome, which makes the increased interest in open architecture more perplexing. In this paper, we explore certain themes of open architecture. We introduce the concept of "windows of interoperability", which can be used to align disparate portions of architecture. Such "windows of interoperability", which concentrate on a reduced set of protocol and interface features, might achieve many of the broader purposes assigned as benefits in open architecture. Since it is possible to engineer proprietary systems that interoperate effectively, this nuanced definition of interoperability may in fact be a more important concept to understand and nurture for effective systems engineering and maintenance.

  16. Open and closed systems in data analysis entropy

    SciTech Connect

    Jafari, H.R.

    1990-01-01

    This dissertation presents and efficient and integrated approach to data analysis. Entropy data analysis is an evolution of reconstructability analysis, which investigates the relationships between parts and wholes. The central theme of the dissertation is the development of a system to condense the information in a data set into a small number of parameters. The new system is called a k-system. k-system analysis goes beyond traditional data analysis in that it has the potentiality for changes to be made to a system; and the impact of these changes can be evaluated. k-system can be useful in designing and evaluating open and closed systems. The behavior of these systems is measured by the k(.) function. The k-system is a closed system. The concept of open comes about when the author tries to reconstruct the k-system starting with an empty system which contains no information. He adds information until he is satisfied that this constructed system adequately reproduces the k-system. The dissertation identifies and isolates the mathematics in the k-system algorithms that determine an open or closed system. It will change the algorithms to offer the option of an open or closed system, and then implement these changes in the k-system algorithms for option of an open or closed system.

  17. Importance of Hydrogeological Conditions on Open-loop Geothermal System

    NASA Astrophysics Data System (ADS)

    Park, D.; Bae, G.; Kim, S.; Lee, K.

    2013-12-01

    The open-loop geothermal system has been known as an eco-friendly, energy-saving, and cost-efficient alternative for the cooling and heating of buildings with directly using the relatively stable temperature of groundwater. Thus, hydrogeological properties of aquifer, such as hydraulic conductivity and storage, must be important in the system application. The study site is located near Han-river, Korea, and because of the well-developed alluvium it might be a typical site appropriate to this system requiring an amount of groundwater. In this study, the first objective of numerical experiments was to find the best distributions of pumping and injection wells suitable to the hydrogeological conditions of the site for the efficient and sustainable system operation. The aquifer has a gravel layer at 15m depth below the ground surface and the river and the agricultural field, which may be a potential contaminant source, are located at the west and east sides, respectively. Under the general conditions that the regional groundwater flows from the east to the river, the locally reversed well distribution, locating the pumping well at upgradient and the injection well at downgradient of the regional flow, was most sustainable. The gravel layer with high hydraulic conductivity caused a little drawdown despite of an amount of pumping and allowed to stably reinject the used groundwater in all the cases, but it provided a passage transferring the injected heat to the pumping well quickly, particularly in the cases locating the injection well at the upgradient. This thermal interference was more severe in the cases of the short distance between the wells. The high conductive layer is also a reason that the seasonal role conversion of wells for the aquifer thermal energy storage was ineffective in this site. Furthermore, the well distribution vertical to the regional groundwater flow was stable, but not best, and, thus, it may be a good choice in the conditions that the regional groundwater flow direction has often been changed. Any effects of the seasonal river temperature variation and contaminant sources were not found on the wells because of the well screen installed at only the relatively deep gravel layer. Finally, it was evaluated whether if these results are valid in a homogeneous aquifer with the full screen of wells and the aquifer having a sediment layer with high hydraulic conductivity at a shallow depth, which are also typical aquifers near river. All the results concluded that it is essential to investigate and understand the site-specific hydrogeological conditions for the successful application of open-loop geothermal system.

  18. Open quantum systems and error correction

    NASA Astrophysics Data System (ADS)

    Shabani Barzegar, Alireza

    Quantum effects can be harnessed to manipulate information in a desired way. Quantum systems which are designed for this purpose are suffering from harming interaction with their surrounding environment or inaccuracy in control forces. Engineering different methods to combat errors in quantum devices are highly demanding. In this thesis, I focus on realistic formulations of quantum error correction methods. A realistic formulation is the one that incorporates experimental challenges. This thesis is presented in two sections of open quantum system and quantum error correction. Chapters 2 and 3 cover the material on open quantum system theory. It is essential to first study a noise process then to contemplate methods to cancel its effect. In the second chapter, I present the non-completely positive formulation of quantum maps. Most of these results are published in [Shabani and Lidar, 2009b,a], except a subsection on geometric characterization of positivity domain of a quantum map. The real-time formulation of the dynamics is the topic of the third chapter. After introducing the concept of Markovian regime, A new post-Markovian quantum master equation is derived, published in [Shabani and Lidar, 2005a]. The section of quantum error correction is presented in three chapters of 4, 5, 6 and 7. In chapter 4, we introduce a generalized theory of decoherence-free subspaces and subsystems (DFSs), which do not require accurate initialization (published in [Shabani and Lidar, 2005b]). In Chapter 5, we present a semidefinite program optimization approach to quantum error correction that yields codes and recovery procedures that are robust against significant variations in the noise channel. Our approach allows us to optimize the encoding, recovery, or both, and is amenable to approximations that significantly improve computational cost while retaining fidelity (see [Kosut et al., 2008] for a published version). Chapter 6 is devoted to a theory of quantum error correction (QEC) that applies to any linear map, in particular maps that are not completely positive (CP). This is a complementary to the second chapter which is published in [Shabani and Lidar, 2007]. In the last chapter 7 before the conclusion, a formulation for evaluating the performance of quantum error correcting codes for a general error model is presented, also published in [Shabani, 2005]. In this formulation, the correlation between errors is quantified by a Hamiltonian description of the noise process. In particular, we consider Calderbank-Shor-Steane codes and observe a better performance in the presence of correlated errors depending on the timing of the error recovery.

  19. Fine-Scale Distribution and Spatial Variability of Benthic Invertebrate Larvae in an Open Coastal Embayment in

    E-print Network

    deYoung, Brad

    Fine-Scale Distribution and Spatial Variability of Benthic Invertebrate Larvae in an Open Coastal- scale (0.5 km) of variability in the horizontal distributions of benthic invertebrate larvae and related (2014) Fine-Scale Distribution and Spatial Variability of Benthic Invertebrate Larvae in an Open Coastal

  20. Stabilized fiber-optic frequency distribution system

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Lutes, G. F.; Sydnor, R. L.

    1989-01-01

    A technique for stabilizing reference frequencies transmitted over fiber-optic cable in a frequency distribution system is discussed. The distribution system utilizes fiber-optic cable as the transmission medium to distribute precise reference signals from a frequency standard to remote users. The stability goal of the distribution system is to transmit a 100-MHz signal over a 22-km fiber-optic cable and maintain a stability of 1 part in 10(17) for 1000-second averaging times. Active stabilization of the link is required to reduce phase variations produced by environmental effects, and is achieved by transmitting the reference signal from the frequency standard to the remote unit and then reflecting back to the reference unit over the same optical fiber. By comparing the phase of the transmitted and reflected signals at the reference unit, phase variations of the remote signal can be measured. An error voltage derived from the phase difference between the two signals is used to add correction phase.

  1. Implementation of Grid Tier 2 and Tier 3 facilities on a Distributed OpenStack Cloud

    NASA Astrophysics Data System (ADS)

    Limosani, Antonio; Boland, Lucien; Coddington, Paul; Crosby, Sean; Huang, Joanna; Sevior, Martin; Wilson, Ross; Zhang, Shunde

    2014-06-01

    The Australian Government is making a AUD 100 million investment in Compute and Storage for the academic community. The Compute facilities are provided in the form of 30,000 CPU cores located at 8 nodes around Australia in a distributed virtualized Infrastructure as a Service facility based on OpenStack. The storage will eventually consist of over 100 petabytes located at 6 nodes. All will be linked via a 100 Gb/s network. This proceeding describes the development of a fully connected WLCG Tier-2 grid site as well as a general purpose Tier-3 computing cluster based on this architecture. The facility employs an extension to Torque to enable dynamic allocations of virtual machine instances. A base Scientific Linux virtual machine (VM) image is deployed in the OpenStack cloud and automatically configured as required using Puppet. Custom scripts are used to launch multiple VMs, integrate them into the dynamic Torque cluster and to mount remote file systems. We report on our experience in developing this nation-wide ATLAS and Belle II Tier 2 and Tier 3 computing infrastructure using the national Research Cloud and storage facilities.

  2. 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.

  3. 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.

  4. 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.

  5. Part III: AFS - A Secure Distributed File System

    SciTech Connect

    Wachsmann, A.; /SLAC

    2005-06-29

    AFS is a secure distributed global file system providing location independence, scalability and transparent migration capabilities for data. AFS works across a multitude of Unix and non-Unix operating systems and is used at many large sites in production for many years. AFS still provides unique features that are not available with other distributed file systems even though AFS is almost 20 years old. This age might make it less appealing to some but with IBM making AFS available as open-source in 2000, new interest in use and development was sparked. When talking about AFS, people often mention other file systems as potential alternatives. Coda (http://www.coda.cs.cmu.edu/) with its disconnected mode will always be a research project and never have production quality. Intermezzo (http://www.inter-mezzo.org/) is now in the Linux kernel but not available for any other operating systems. NFSv4 (http://www.nfsv4.org/) which picked up many ideas from AFS and Coda is not mature enough yet to be used in serious production mode. This article presents the rich features of AFS and invites readers to play with it.

  6. Open Source Vision Library (OpenVL) Based Local Positioning System Changsong Shen, Steve Oldridge and Sidney Fels

    E-print Network

    British Columbia, University of

    Open Source Vision Library (OpenVL) Based Local Positioning System Changsong Shen, Steve Oldridge}@ece.ubc.ca Abstract This paper presents an Open Source Vision Library (OpenVL) for hardware acceleration of video-based surveillance systems and other computer vision applications to facilitate low latency, real-time response. Our

  7. Development of a Network-based Real-Time Robot Control System over IEEE 1394: Using Open Source Software Platform

    Microsoft Academic Search

    M. O. F. Sarker; Chang Hwan Kim; Jeong-San Cho; Bum-Jae You

    2006-01-01

    Network-based distributed processing and hard real-time requirement significantly increase the complexity of a robot hardware and software system. This paper describes the open and modular approach to design and implement a real-time robot control system using open source software (OSS) which include a Linux-based real-time operating system (RTOS), Xenomai (formerly known as the fusion branch of real time application interface,

  8. Derived virtual devices: a secure distributed file system mechanism

    NASA Technical Reports Server (NTRS)

    VanMeter, Rodney; Hotz, Steve; Finn, Gregory

    1996-01-01

    This paper presents the design of derived virtual devices (DVDs). DVDs are the mechanism used by the Netstation Project to provide secure shared access to network-attached peripherals distributed in an untrusted network environment. DVDs improve Input/Output efficiency by allowing user processes to perform I/O operations directly from devices without intermediate transfer through the controlling operating system kernel. The security enforced at the device through the DVD mechanism includes resource boundary checking, user authentication, and restricted operations, e.g., read-only access. To illustrate the application of DVDs, we present the interactions between a network-attached disk and a file system designed to exploit the DVD abstraction. We further discuss third-party transfer as a mechanism intended to provide for efficient data transfer in a typical NAP environment. We show how DVDs facilitate third-party transfer, and provide the security required in a more open network environment.

  9. Open-ended magnetic confinement systems for fusion

    SciTech Connect

    Post, R.F.; Ryutov, D.D.

    1995-05-01

    Magnetic confinement systems that use externally generated magnetic fields can be divided topologically into two classes: ``closed`` and `open``. The tokamak, the stellarator, and the reversed-field-pinch approaches are representatives of the first category, while mirror-based systems and their variants are of the second category. While the recent thrust of magnetic fusion research, with its emphasis on the tokamak, has been concentrated on closed geometry, there are significant reasons for the continued pursuit of research into open-ended systems. The paper discusses these reasons, reviews the history and the present status of open-ended systems, and suggests some future directions for the research.

  10. Nonlocal Memory Effects in the Dynamics of Open Quantum Systems

    NASA Astrophysics Data System (ADS)

    Laine, Elsi-Mari; Breuer, Heinz-Peter; Piilo, Jyrki; Li, Chuan-Feng; Guo, Guang-Can

    2012-05-01

    We explore the possibility to generate nonlocal dynamical maps of an open quantum system through local system-environment interactions. Employing a generic decoherence process induced by a local interaction Hamiltonian, we show that initial correlations in a composite environment can lead to nonlocal open system dynamics which exhibit strong memory effects, although the local dynamics is Markovian. In a model of two entangled photons interacting with two dephasing environments, we find a direct connection between the degree of memory effects and the amount of correlation in the initial environmental state. The results demonstrate that, contrary to conventional wisdom, enlarging an open system can change the dynamics from Markovian to non-Markovian.

  11. 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.

  12. 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. (California Univ., Davis, CA (USA). Div. of Computer Science); Grance, T. (Air Force Cryptologic Support Center, San Antonio, TX (USA)); Mansur, D.L.; Pon, K.L. (Lawrence Livermore National Lab., CA (USA)); Smaha, S.E. (Haystack Labs., Inc., Austin, TX (USA))

    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.

  13. 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.

  14. Relativistic Quantum Metrology in Open System Dynamics

    PubMed Central

    Tian, Zehua; Wang, Jieci; Fan, Heng; Jing, Jiliang

    2015-01-01

    Quantum metrology studies the ultimate limit of precision in estimating a physical quantity if quantum strategies are exploited. Here we investigate the evolution of a two-level atom as a detector which interacts with a massless scalar field using the master equation approach for open quantum system. We employ local quantum estimation theory to estimate the Unruh temperature when probed by a uniformly accelerated detector in the Minkowski vacuum. In particular, we evaluate the Fisher information (FI) for population measurement, maximize its value over all possible detector preparations and evolution times, and compare its behavior with that of the quantum Fisher information (QFI). We find that the optimal precision of estimation is achieved when the detector evolves for a long enough time. Furthermore, we find that in this case the FI for population measurement is independent of initial preparations of the detector and is exactly equal to the QFI, which means that population measurement is optimal. This result demonstrates that the achievement of the ultimate bound of precision imposed by quantum mechanics is possible. Finally, we note that the same configuration is also available to the maximum of the QFI itself. PMID:25609187

  15. 47 CFR 76.1503 - Carriage of video programming providers on open video systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...programming providers on open video systems. 76.1503 Section 76.1503...CABLE TELEVISION SERVICE Open Video Systems § 76.1503 Carriage of video programming providers on open video systems. (a) Non-discrimination...

  16. 47 CFR 76.1504 - Rates, terms and conditions for carriage on open video systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...conditions for carriage on open video systems. 76.1504 Section 76.1504...CABLE TELEVISION SERVICE Open Video Systems § 76.1504 Rates, terms and conditions for carriage on open video systems. (a) Reasonable rate...

  17. 47 CFR 76.1504 - Rates, terms and conditions for carriage on open video systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...conditions for carriage on open video systems. 76.1504 Section 76.1504...CABLE TELEVISION SERVICE Open Video Systems § 76.1504 Rates, terms and conditions for carriage on open video systems. (a) Reasonable rate...

  18. 47 CFR 76.1504 - Rates, terms and conditions for carriage on open video systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...conditions for carriage on open video systems. 76.1504 Section 76.1504...CABLE TELEVISION SERVICE Open Video Systems § 76.1504 Rates, terms and conditions for carriage on open video systems. (a) Reasonable rate...

  19. Identifier protection in a distributed operating system

    SciTech Connect

    Nessett, D.M.

    1981-06-06

    A scheme was recently presented to protect capabilities in a distributed operating system. This scheme uses public-key encryption to ensure that capabilities cannot be stolen in a form useful to the thief nor forged by an unauthorized process or user. Unfortunately, security and efficiency considerations make currently available public-key encryption techniques unattractive. This report focuses on the characteristics an identifier protection scheme must possess and on the use of secret-key encryption to provide identifier protection.

  20. Reliability evaluation of distribution systems containing renewable distributed generations

    NASA Astrophysics Data System (ADS)

    Alkuhayli, Abdulaziz Abddullah

    Reliability evaluation of distribution networks, including islanded microgrid cases, is presented. The Monte Carlo simulation algorithm is applied to a test network. The network includes three types of distributed energy resources solar photovoltaic (PV), wind turbine (WT) and gas turbine (GT). These distributed generators contribute to supply part of the load during grid-connected mode, but supply the entire load during islanded microgrid operation. PV and WT stochastic models have been used to simulate the randomness of these resources. This study shows that the implementation of distributed generations can improve the reliability of the distribution networks.

  1. 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.

  2. 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.

  3. Separating Data and Control Transfer in Distributed Operating Systems

    E-print Network

    Thekkath, Chandramohan A.

    Separating Data and Control Transfer in Distributed Operating Systems Chandramohan A. Thekkath, October 1994. 1 #12;Separating Data and Control Transfer in Distributed Operating Systems Chandramohan Ath International Conference on Architectural Support for Programming Languages and Operating Systems

  4. On-Site Wastewater Treatment Systems: Subsurface Drip Distribution

    E-print Network

    Lesikar, Bruce J.

    1999-09-06

    A subsurface drip system distributes wastewater to the lawn through a system of tubing installed below the ground. This publication explains the advantages and disadvantages of subsurface drip distribution systems, as well as estimated costs...

  5. On-Site Wastewater Treatment Systems: Spray Distribution (Spanish)

    E-print Network

    Lesikar, Bruce J.; Enciso, Juan

    1999-08-12

    Spray distribution systems for wastewater treated on site are much like lawn irrigation systems. This publication explains the advantages, disadvantages, maintenance steps and estimated costs of spray distribution systems....

  6. 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.

  7. Automating database management for distributed database systems

    NASA Astrophysics Data System (ADS)

    Joy, Steven P.; King, Todd A.; Walker, Raymond J.

    1993-08-01

    The management of large databases can be a time consuming and tedious task without tools to automate the process. In order to facilitata the process, a database design philosophy which is consistent with application objectives must be adopted. The Planetary Plasma Interactions (PPI) Node of the Planetary Data System (PDS) provides users with a software application which allows for rapid retrieval (for examination or extraction) of datasets which are distributed and which may exist in more than one location simultaneously. In addition, the application software, which interacts with both a local and a centralized database management system (dbms) via a client-server architecture, also is distributed. The basic problem lies in keeping all of the information current in a dynamic data environment so that the application software, regardless of its location, can access any data in the system with the greatest possible throughput. In addressing this problem the PDS/PPI Node has adopted a standardized architecture [2] and has chosen to package data management information with the data themselves as a set of detached relational flatfiles. At the PDS/PPI Node automated dbms tools are being developed which update both local and central management systems by using the information provided along with the datasets. This information can be stored in any relational database system or it can be accessed and manipulated outside of a dbms. Science data are not maintained under direct dbms control.

  8. Integrated, multivendor distributed data-acquisition system

    SciTech Connect

    Butner, D.N.; Drlik, M.; Meyer, W.H.; Moller, J.M.; Preckshot, G.G.

    1988-08-01

    A distributed data-acquisition system that used various computer hardware and software is being developed to support magnetic fusion experiments at Lawrence Livermore National Laboratory (LLNL). The experimental sequence of operations is controlled by a supervisory program, which coordinates software running on Digital Equipment Corporation (DEC) VAX computers, Hewlett--Packard (HP) UNIX-based workstations, and HP b-smcapsASIc-smcaps desktop computers. An interprocess communication system (IPCS) allows programs to communicate with one another in a standard manner regardless of program location in the network or of operating system and hardware differences. We discuss the design and implementation of this data-acquisition system with particular emphasis on the coordination model and the IPCS.

  9. Rotifer size distribution changes during transient phases in open cultures

    Microsoft Academic Search

    Martin E. Boraas; Dianne B. Seale; Joseph E. Boxhorn; James N. McNair

    1998-01-01

    In laboratory studies, rotifers (Brachionus calyciflorus) were monitored under well-defined environmental conditions at different supply rates of a unicellular algal food (Chlorella vulgaris). Rotifer size frequency distributions are described for conditions of steady-state growth, exponential increase, and starvation. Temporal fluctuations in size-age structure are described for cultures during transient conditions during the approach to a steady state and following step

  10. Quantum trajectories and open many-body quantum systems

    E-print Network

    Andrew J. Daley

    2014-05-26

    The study of open quantum systems has become increasingly important in the past years, as the ability to control quantum coherence on a single particle level has been developed in a wide variety of physical systems. In quantum optics, the study of open systems goes well beyond understanding the breakdown of quantum coherence. There, the coupling to the environment is sufficiently well understood that it can be manipulated to drive the system into desired quantum states, or to project the system onto known states via feedback in quantum measurements. Many mathematical frameworks have been developed to describe such systems, which for atomic, molecular, and optical (AMO) systems generally provide a very accurate description of the open quantum system on a microscopic level. In recent years, AMO systems including cold atomic and molecular gases and trapped ions have been applied heavily to the study of many-body physics, and it has become important to extend previous understanding of open system dynamics in single- and few-body systems to this many-body context. A key formalism that has already proven very useful in this context is the quantum trajectories technique. This was developed as a numerical tool for studying dynamics in open quantum systems, and falls within a broader framework of continuous measurement theory as a way to understand the dynamics of large classes of open quantum systems. We review the progress that has been made in studying open many-body systems in the AMO context, focussing on the application of ideas from quantum optics, and on the implementation and applications of quantum trajectories methods. Control over dissipative processes promises many further tools to prepare interesting and important states in strongly interacting systems, including the realisation of parameter regimes in quantum simulators that are inaccessible via current techniques.

  11. Open Source Library Management Systems: A Multidimensional Evaluation

    ERIC Educational Resources Information Center

    Balnaves, Edmund

    2008-01-01

    Open source library management systems have improved steadily in the last five years. They now present a credible option for small to medium libraries and library networks. An approach to their evaluation is proposed that takes account of three additional dimensions that only open source can offer: the developer and support community, the source…

  12. Modeling and Managing State in Distributed Systems: The Role of OGSI and WSRF

    Microsoft Academic Search

    IAN FOSTER; KARL CZAJKOWSKI; DONALD F. FERGUSON; JEFFREY FREY; STEVE GRAHAM; TOM MAGUIRE; DAVID SNELLING; STEVEN TUECKE

    2005-01-01

    We often encounter in distributed systems the need to model, access, and manage state. This state may be, for example, data in a purchase order, service level agreements representing resource availability, or the current load on a computer. We introduce two closely related approaches to modeling and manipulating state within a Web services (WS) framework: the Open Grid Services Infrastructure

  13. Comprehensive Large Array-data Stewardship System (CLASS)A Fully-distributed System

    NASA Astrophysics Data System (ADS)

    Rank, R.; Reynolds, R. G.

    2005-12-01

    The Comprehensive Large Array-data Stewardship System (CLASS) is moving from its dual site operation to a multi-node, distributed architecture. The next step in this process is to move to a three-node architecture in North Carolina, Colorado, and West Virginia. Subsequently, CLASS will transition to a fully-distributed system by migrating to a highly structured, layered (distributed) architecture. While so-called "service-oriented" architectures often describe numerous layers, CLASS refers to two primary layers: infrastructure and application. An infrastructure layer is needed to provide common capabilities for distributed application development and deployment. Applications interact with the infrastructure layer though stable, published interfaces. The infrastructure layer abstracts the complexities of distributed computing such that developers, system administrators, operators, and others can focus on CLASS application logic rather than the mechanisms which support it. The application layer will use artifacts to implement CLASS-specific capabilities or services. Ingest, dissemination, search, and order are a few among many examples. Application layer components utilize services from the infrastructure to provide distributed behavior, and to simplify and streamline application development, deployment, and operations processes. As CLASS evolves to become a fully-distributed system, each transitional phase supports the need for CLASS's architecture to provide a context of reliability, performance, and extensibility. Moreover, these important qualities must be achieved in a constantly and quickly changing environment, emphasizing the need for CLASS to be easily adaptable in its pursuit of these goals. Transitioning to a distributed, open, heterogeneous environment with a powerful and stable infrastructure and fine-grained, decoupled applications will make it possible for CLASS to achieve these objectives economically and rapidly.

  14. Open cycle ocean thermal energy conversion system

    DOEpatents

    Wittig, J. Michael (West Goshen, PA)

    1980-01-01

    An improved open cycle ocean thermal energy conversion system including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flowpath and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support therefor and impart a desired flow direction to the steam.

  15. OSGi-based open mobile asset management system

    Microsoft Academic Search

    Xiaolin Ma; Meina Song; Lin Qiu; Haihong E

    2010-01-01

    In the conventional asset management systems, users cannot customize services sets flexibly because of certain fixed mode in the systems. Another problem is that, the systems which integrate RFID technology to monitor the assets have to be redeployed when the RFID equipments are replaced. In this paper, we propose an open mobile asset management system based on OSGi to solve

  16. Performance studies for an experimental solar open-cycle liquid desiccant air dehumidification system

    Microsoft Academic Search

    S. Patnaik; T. G. Lenz; G. O. G. Loef

    1990-01-01

    A nominal 10.5-kW (3-ton) open-cycle liquid desiccant dehumidification system has been designed, installed, and successfully operated at the Solar Energy Applications Laboratory, Colorado State University. Packed beds units were used to dry the air in the dehumidifier and to concentrate the desiccant in the regenerator. Liquid distribution in the regenerator was studied for two systems: a gravity tray distributor, and

  17. Refrigerant Leakage Detection and Diagnosis for a Distributed Refrigeration System

    Microsoft Academic Search

    Kriengkrai Assawamartbunlue; Michael J. Brandemuehl

    2006-01-01

    A new technique to detect and diagnose leakage in a distributed refrigeration system is proposed in this paper. Unlike a simple refrigeration system of an HVAC system, a distributed refrigeration system, such as the refrigeration system in a supermarket, consists of several racks of compressors and evaporators, large condenser systems on the roof, meters of refrigerant piping systems, and liquid

  18. A semiclassical theory of quantum noise in open chaotic systems

    E-print Network

    B. C. Bag; S. Chaudhuri; J. Ray Chaudhuri; D. S. Ray

    1998-11-13

    We consider the quantum evolution of classically chaotic systems in contact with surroundings. Based on $\\hbar$-scaling of an equation for time evolution of the Wigner's quasi-probability distribution function in presence of dissipation and thermal diffusion we derive a semiclassical equation for quantum fluctuations. This identifies an early regime of evolution dominated by fluctuations in the curvature of the potential due to classical chaos and dissipation. A stochastic treatment of this classical fluctuations leads us to a Fokker-Planck equation which is reminiscent of Kramers' equation for thermally activated processes. This reveals an interplay of three aspects of evolution of quantum noise in weakly dissipative open systems; the reversible Liouville flow, the irreversible chaotic diffusion which is characteristic of the system itself, and irreversible dissipation induced by the external reservoir. It has been demonstrated that in the dissipation-free case a competition between Liouville flow in the contracting direction of phase space and chaotic diffusion sets a critical width in the Wigner function for quantum fluctuations. We also show how the initial quantum noise gets amplified by classical chaos and ultimately equilibrated under the influence of dissipation. We establish that there exists a critical limit to the expansion of phase space. The limit is determined by chaotic diffusion and dissipation. Making use of appropriate quantum-classical correspondence we verify the semiclassical analysis by the fully quantum simulation in a chaotic quartic oscillator.

  19. RESEARCH Open Access The distribution of potential West Nile virus

    E-print Network

    Culex Pipiens Pipiens; Culex Pipiens; America A Padilla-viveros; Minerva Camacho-nuez; Alfonso Diaz-perez; Barry J Beaty

    Background: Culex spp. mosquitoes are considered to be the most important vectors of West Nile virus (WNV) detected in at least 34 species of mosquitoes in the United States. In North America, Culex pipiens pipiens, Culex pipiens quinquefasciatus, andCulex tarsalis are all competent vectors of WNV, which is considered to be enzootic in the United States and has also been detected in equines and birds in many states of Mexico and in humans in Nuevo Leon. There is potential for WNV to be introduced into Mexico City by various means including infected mosquitoes on airplanes, migrating birds, ground transportation and infected humans. Little is known of the geographic distribution of Culex pipiens complex mosquitoes and hybrids in Mexico City. Culex pipiens pipiens preferentially feed on avian hosts; Culex pipiens quinquefasciatus have historically been considered to prefer mammalian hosts; and hybrids of these two species could theoretically serve as bridge vectors to transmit WNV from avian hosts to humans and other mammalian hosts. In order to address the potential of WNV being introduced into Mexico City, we have determined the identity and spatial distribution of Culex pipiens complex mosquitoes and their hybrids. Results: Mosquito larvae collected from 103 sites throughout Mexico City during 2004-2005 were identified as Culex, Culiseta or Ochlerotatus by morphological analysis. Within the genus Culex, specimens were further identified as Culex tarsalis or as belonging to the Culex pipiens complex. Members of the Culex pipiens complex were separated by

  20. 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.

  1. 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.

  2. 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.

  3. Software Engineering Education in the Era of Outsourcing, Distributed Development, and Open Source

    E-print Network

    Perry, Dewayne E.

    to navigate the increasingly dynamic environment that soft- ware engineering has become, and 2) to equip them, but at the same time, making integration technologies, architectures and frameworks, and software engineeringSoftware Engineering Education in the Era of Outsourcing, Distributed Development, and Open Source

  4. The Production and Distribution of Knowledge through Open and Distance Learning

    Microsoft Academic Search

    Stephen Fox

    1989-01-01

    Open and distance learning (ODL) technology offers a new form of market mechanism for the distribution of knowledge which is increasingly presented as a commodity like any other. Information technology (IT) is also having an impact on the technical and social production of knowledge and higher learning in general. This paper will explore a range of issues arising from this

  5. A DISTRIBUTED INTELLIGENT AUTOMATED DEMAND RESPONSE BUILDING MANAGEMENT SYSTEM

    SciTech Connect

    Auslander, David; Culler, David; Wright, Paul; Lu, Yan; Piette, Mary

    2013-12-30

    The goal of the 2.5 year Distributed Intelligent Automated Demand Response (DIADR) project was to reduce peak electricity load of Sutardja Dai Hall at UC Berkeley by 30% while maintaining a healthy, comfortable, and productive environment for the occupants. We sought to bring together both central and distributed control to provide “deep” demand response1 at the appliance level of the building as well as typical lighting and HVAC applications. This project brought together Siemens Corporate Research and Siemens Building Technology (the building has a Siemens Apogee Building Automation System (BAS)), Lawrence Berkeley National Laboratory (leveraging their Open Automated Demand Response (openADR), Auto-­?Demand Response, and building modeling expertise), and UC Berkeley (related demand response research including distributed wireless control, and grid-­?to-­?building gateway development). Sutardja Dai Hall houses the Center for Information Technology Research in the Interest of Society (CITRIS), which fosters collaboration among industry and faculty and students of four UC campuses (Berkeley, Davis, Merced, and Santa Cruz). The 141,000 square foot building, occupied in 2009, includes typical office spaces and a nanofabrication laboratory. Heating is provided by a district heating system (steam from campus as a byproduct of the campus cogeneration plant); cooling is provided by one of two chillers: a more typical electric centrifugal compressor chiller designed for the cool months (Nov-­? March) and a steam absorption chiller for use in the warm months (April-­?October). Lighting in the open office areas is provided by direct-­?indirect luminaries with Building Management System-­?based scheduling for open areas, and occupancy sensors for private office areas. For the purposes of this project, we focused on the office portion of the building. Annual energy consumption is approximately 8053 MWh; the office portion is estimated as 1924 MWh. The maximum peak load during the study period was 1175 kW. Several new tools facilitated this work, such as the Smart Energy Box, the distributed load controller or Energy Information Gateway, the web-­?based DR controller (dubbed the Central Load-­?Shed Coordinator or CLSC), and the Demand Response Capacity Assessment & Operation Assistance Tool (DRCAOT). In addition, an innovative data aggregator called sMAP (simple Measurement and Actuation Profile) allowed data from different sources collected in a compact form and facilitated detailed analysis of the building systems operation. A smart phone application (RAP or Rapid Audit Protocol) facilitated an inventory of the building’s plug loads. Carbon dioxide sensors located in conference rooms and classrooms allowed demand controlled ventilation. The extensive submetering and nimble access to this data provided great insight into the details of the building operation as well as quick diagnostics and analyses of tests. For example, students discovered a short-­?cycling chiller, a stuck damper, and a leaking cooling coil in the first field tests. For our final field tests, we were able to see how each zone was affected by the DR strategies (e.g., the offices on the 7th floor grew very warm quickly) and fine-­?tune the strategies accordingly.

  6. Information Ecology: Open System Environment for Data, Memories and Knowing

    E-print Network

    Bowker, Geoffrey C.

    Information Ecology: Open System Environment for Data, Memories and Knowing Karen S. Baker@scu.edu Abstract. An information ecology provides a conceptual framework to consider data, the creation Ecological Research (LTER) community, presents some manifestations of traditionally unreported `invisible

  7. Conserved current in Markovian open-quantum systems

    SciTech Connect

    Bodor, Andras; Diosi, Lajos [Department of the Physics of Complex Systems, Eoetvoes University, H-1117 Budapest (Hungary); Research Institute for Particle and Nuclear Physics, H-1525 Budapest 114, P.O. Box 49 (Hungary)

    2006-06-15

    We reexamine the Markovian approximation of local current in open quantum systems, discussed recently by Gebauer and Car. Our derivation is more transparent; the proof of the current conservation becomes explicit and easy.

  8. Stability Analysis of Distributed Order Fractional Chen System

    PubMed Central

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

    2013-01-01

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

  9. 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.

  10. The use of small advanced turbine units in distribution systems

    SciTech Connect

    Wong, E.R.

    1995-12-31

    There is a tremendous future for the application of small- and medium-sized advanced gas turbine systems in the world markets. Modern, industrialized countries; developing countries like China and the former republics of the Soviet Union; as well as island-based economies, such as those in Southeast Asia -- Philippines, Singapore, Malaysia, and Indonesia--will be able to realize the economic advantages and environmental benefits of what is now becoming known as {open_quotes}distributed resources{close_quotes}. I am more convinced of this opinion after delivering s similar speech and conversing with conferees at POWER-GEN Asia 1995 held in Singapore in late September of this year; and discussing the subject with a high level delegation from China that visited the Energy Commission in early October. The interest, at least amongst this small group of people was nothing short of a market researcher`s dream. While my focus today is on small turbines, we should realize that when these advanced, clean units become commercially available, perhaps as early as four or five years from now, other distributed generation resources such as solar photovoltaic, and fuel cells, will become competitors at the distribution level of electrical service.

  11. 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.

  12. A System for Open-Access 3 He Human Lung

    E-print Network

    Walsworth, Ronald L.

    A System for Open-Access 3 He Human Lung Imaging at Very Low Field I.C. RUSET,1 L.L. TSAI,2,3 R describe a prototype system built to allow open-access very-low-field MRI of human lungs using laser images of human lungs. We include discussion on challenges unique to imaging at 50­200 kHz, including

  13. 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%.

  14. Distributed computer system enhances productivity for SRB joint optimization

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    Initial calculations of a redesign of the solid rocket booster joint that failed during the shuttle tragedy showed that the design had a weight penalty associated with it. Optimization techniques were to be applied to determine if there was any way to reduce the weight while keeping the joint opening closed and limiting the stresses. To allow engineers to examine as many alternatives as possible, a system was developed consisting of existing software that coupled structural analysis with optimization which would execute on a network of computer workstations. To increase turnaround, this system took advantage of the parallelism offered by the finite difference technique of computing gradients to allow several workstations to contribute to the solution of the problem simultaneously. The resulting system reduced the amount of time to complete one optimization cycle from two hours to one-half hour with a potential of reducing it to 15 minutes. The current distributed system, which contains numerous extensions, requires one hour turnaround per optimization cycle. This would take four hours for the sequential system.

  15. Dynamic modeling and control design of microturbine distributed generation systems

    Microsoft Academic Search

    Xunwei Yu; Zhenhua Jiang; Atideh Abbasi

    2009-01-01

    Distributed generation draws increasing attention because of the energy shortage and environmental protection considerations. Furthermore, distribution power generation can improve the power system stability and reliability, providing the local power supply economically. Microturbine based power generation has many applications in distributed generation. In this paper, a mathematical model of a microturbine distributed generation system connected to the utility grid is

  16. 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.

  17. An integrated load management, distribution automation and distribution SCADA system for Old Dominion Electric Cooperative

    Microsoft Academic Search

    M. L. Chan; W. H. Jr. Crouch

    1990-01-01

    This paper presents a computer and communications system for controlling the operations of load management, distribution automation and distribution SCADA for a G and T cooperative, Old Dominion Electric Cooperative and its twelve member cooperatives. The system is currently being designed and delivered by a team of vendors, which involves an EMS\\/SCADA system vendor and a load management\\/distribution automation equipment

  18. OpenDanubia - An integrated, modular simulation system to support regional water resource management

    NASA Astrophysics Data System (ADS)

    Muerth, M.; Waldmann, D.; Heinzeller, C.; Hennicker, R.; Mauser, W.

    2012-04-01

    The already completed, multi-disciplinary research project GLOWA-Danube has developed a regional scale, integrated modeling system, which was successfully applied on the 77,000 km2 Upper Danube basin to investigate the impact of Global Change on both the natural and anthropogenic water cycle. At the end of the last project phase, the integrated modeling system was transferred into the open source project OpenDanubia, which now provides both the core system as well as all major model components to the general public. First, this will enable decision makers from government, business and management to use OpenDanubia as a tool for proactive management of water resources in the context of global change. Secondly, the model framework to support integrated simulations and all simulation models developed for OpenDanubia in the scope of GLOWA-Danube are further available for future developments and research questions. OpenDanubia allows for the investigation of water-related scenarios considering different ecological and economic aspects to support both scientists and policy makers to design policies for sustainable environmental management. OpenDanubia is designed as a framework-based, distributed system. The model system couples spatially distributed physical and socio-economic process during run-time, taking into account their mutual influence. To simulate the potential future impacts of Global Change on agriculture, industrial production, water supply, households and tourism businesses, so-called deep actor models are implemented in OpenDanubia. All important water-related fluxes and storages in the natural environment are implemented in OpenDanubia as spatially explicit, process-based modules. This includes the land surface water and energy balance, dynamic plant water uptake, ground water recharge and flow as well as river routing and reservoirs. Although the complete system is relatively demanding on data requirements and hardware requirements, the modular structure and the generic core system (Core Framework, Actor Framework) allows the application in new regions and the selection of a reduced number of modules for simulation. As part of the Open Source Initiative in GLOWA-Danube (opendanubia.glowa-danube.de) a comprehensive documentation for the system installation was created and both the program code of the framework and of all major components is licensed under the GNU General Public License. In addition, some helpful programs and scripts necessary for the operation and processing of input and result data sets are provided.

  19. Safety and Reliability Driven Task Allocation in Distributed Systems

    Microsoft Academic Search

    S. Srinivasan; Niraj K. Jha

    1999-01-01

    Distributed computer systems are increasingly being employed for critical applications, such as aircraft control, industrial process control, and banking systems. Maximizing performance has been the conventional objective in the allocation of tasks for such systems. Inherently, distributed systems are more complex than centralized systems. The added complexity could increase the potential for system failures. Some work has been done in

  20. Distributions of dissolved vitamin B 12 and Co in coastal and open-ocean environments

    NASA Astrophysics Data System (ADS)

    Panzeca, Caterina; Beck, Aaron J.; Tovar-Sanchez, Antonio; Segovia-Zavala, Jose; Taylor, Gordon T.; Gobler, Christopher J.; Sañudo-Wilhelmy, Sergio A.

    2009-11-01

    Distributions of dissolved vitamin B 12 and total dissolved Co were measured to gain an understanding of the cycling of these interdependent micronutrients in six marine settings including; an upwelling location, a semi-enclosed bay, two urban coastal systems, and two open ocean locations. Along the coast of Baja California, Mexico, concentrations of B 12 and dissolved Co varied from 0.2 to 11 pM and 180 to 990 pM, respectively. At a nearby upwelling station, vitamin B 12 and Co concentrations ranged from 0.3 to 7.0 pM and 22 to 145 pM, and concentrations did not correlate with upwelling intensity. Concentrations of B 12 were highest within Todos Santos Bay, a semi-enclosed bay off the coast of Baja California, Mexico, during a dinoflagellate bloom, ranging from 2 to 61 pM, while Co concentrations varied between 61 and 194 pM. In the anthropogenically impacted Long Island Sound, NY, U.S.A., B 12 levels were between 0.1 and 23 pM and Co concentrations varied from 60 to 1900 pM. However, anthropogenic inputs were not evident in B 12 levels in the San Pedro Basin, located outside Los Angeles, Ca, U.S.A., where concentrations of B 12 were 0.2-1.8 pM, approximating observed open ocean B 12 concentrations. In the Southern Ocean and North Atlantic Ocean, B 12 levels were 0.4-4 pM and 0.2-2 pM, respectively. Total Co concentrations in the Southern Ocean and North Atlantic tended to be low; measuring 26-59 pM and 15-80 pM, respectively. These low Co concentrations may limit B 12 synthesis and its availability to B 12-requiring phytoplankton because the total dissolved Co pool is not necessarily entirely bioavailable.

  1. The AI Bus architecture for distributed knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Schultz, Roger D.; Stobie, Iain

    1991-01-01

    The AI Bus architecture is layered, distributed object oriented framework developed to support the requirements of advanced technology programs for an order of magnitude improvement in software costs. The consequent need for highly autonomous computer systems, adaptable to new technology advances over a long lifespan, led to the design of an open architecture and toolbox for building large scale, robust, production quality systems. The AI Bus accommodates a mix of knowledge based and conventional components, running on heterogeneous, distributed real world and testbed environment. The concepts and design is described of the AI Bus architecture and its current implementation status as a Unix C++ library or reusable objects. Each high level semiautonomous agent process consists of a number of knowledge sources together with interagent communication mechanisms based on shared blackboards and message passing acquaintances. Standard interfaces and protocols are followed for combining and validating subsystems. Dynamic probes or demons provide an event driven means for providing active objects with shared access to resources, and each other, while not violating their security.

  2. A uniform approach for programming distributed heterogeneous computing systems

    PubMed Central

    Grasso, Ivan; Pellegrini, Simone; Cosenza, Biagio; Fahringer, Thomas

    2014-01-01

    Large-scale compute clusters of heterogeneous nodes equipped with multi-core CPUs and GPUs are getting increasingly popular in the scientific community. However, such systems require a combination of different programming paradigms making application development very challenging. In this article we introduce libWater, a library-based extension of the OpenCL programming model that simplifies the development of heterogeneous distributed applications. libWater consists of a simple interface, which is a transparent abstraction of the underlying distributed architecture, offering advanced features such as inter-context and inter-node device synchronization. It provides a runtime system which tracks dependency information enforced by event synchronization to dynamically build a DAG of commands, on which we automatically apply two optimizations: collective communication pattern detection and device-host-device copy removal. We assess libWater’s performance in three compute clusters available from the Vienna Scientific Cluster, the Barcelona Supercomputing Center and the University of Innsbruck, demonstrating improved performance and scaling with different test applications and configurations.

  3. 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.

  4. Distribution in flowing reaction-diffusion systems

    NASA Astrophysics Data System (ADS)

    Kamimura, Atsushi; Herrmann, Hans J.; Ito, Nobuyasu

    2009-12-01

    A power-law distribution is found in the density profile of reacting systems A+B?C+D and 2A?2C under a flow in two and three dimensions. Different densities of reactants A and B are fixed at both ends. For the reaction A+B , the concentration of reactants asymptotically decay in space as x-1/2 and x-3/4 in two dimensions and three dimensions, respectively. For 2A , it decays as log(x)/x in two dimensions. The decay of A+B is explained considering the effect of segregation of reactants in the isotropic case. The decay for 2A is explained by the marginal behavior of two-dimensional diffusion. A logarithmic divergence of the diffusion constant with system size is found in two dimensions.

  5. Distributed fiber optic moisture intrusion sensing system

    DOEpatents

    Weiss, Jonathan D. (Albuquerque, NM)

    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.

  6. Constructing Provenance-Aware Distributed Systems with Data Propagation

    E-print Network

    Jackson, Daniel

    Constructing Provenance-Aware Distributed Systems with Data Propagation by Ian Campbell Jacobi Provenance-Aware Distributed Systems with Data Propagation by Ian Campbell Jacobi Submitted to the Department

  7. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Oxygen distribution system. 23.1445 Section...Miscellaneous Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the dispensing units,...

  8. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Oxygen distribution system. 23.1445 Section...Miscellaneous Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the dispensing units,...

  9. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Oxygen distribution system. 23.1445 Section...Miscellaneous Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the dispensing units,...

  10. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Oxygen distribution system. 23.1445 Section...Miscellaneous Equipment § 23.1445 Oxygen distribution system. (a) Except for flexible lines from oxygen outlets to the dispensing units,...

  11. On-Site Wastewater Treatment Systems: Subsurface Drip Distribution (Spanish)

    E-print Network

    Lesikar, Bruce J.; Enciso, Juan

    1999-08-12

    A subsurface drip system distributes wastewater to the lawn through a system of tubing installed below the ground surface. This publication explains the advantages, disadvantages, maintenance steps and estimated costs of subsurface drip distribution...

  12. Role development in an open access system

    Microsoft Academic Search

    Mary Thorpe

    1988-01-01

    Since the beginning of the 1980s there has been growing pressure on institutions of further and higher education to offer much more flexible opportunities for learning, oriented to the needs of the individual or client rather than to the providing institution primarily. Although a variety of phrases is in use, ‘open learning?s has been used as a shorthand referent for

  13. Open Source Ch Control System Toolkit and Web-Based

    E-print Network

    Cheng, Harry H.

    curricula [1]. Due to the advances of mathematics and computing technology, the modern control engineering Periodicals, Inc. of control education. A number of software packages, such as MATLAB Control System ToolboxOpen Source Ch Control System Toolkit and Web-Based Control System Design for Teaching Automatic

  14. Canopy gas exchange measurements of cotton in an open system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A portable, CETA (Canopy Evapo-Transpiration and Assimilation) chamber system was built and evaluated in 2006. This chamber system is an open or flow-through system that, once field deployed, can operate unattended for extended periods. The CETA chamber consisted of an aluminum framework, 1 m x 0.7...

  15. RESEARCH Open Access Local and systemic innate immune response

    E-print Network

    Paris-Sud XI, Université de

    RESEARCH Open Access Local and systemic innate immune response to secondary human peritonitis: Peritonitis triggers an acute systemic and peritoneal innate immune response with a simultaneous release, there is a paucity of data regard- ing systemic and local innate immune responses during peritonitis in humans

  16. An open system for measuring canopy gas exchange

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three portable, CETA (Canopy Evapo-Transpiration and Assimilation) chamber systems were built and evaluated in 2006. This chamber system is an open or flow-through system that, once deployed in the field, can operate unattended for extended periods (e.g. overnight for example). The CETA chamber con...

  17. The Binary INformation from Open Clusters using SEDs (BINOCS) Project: Radial Migration of Binary Systems in Open Clusters

    NASA Astrophysics Data System (ADS)

    Thompson, Benjamin A.; Frinchaboy, Peter M.

    2015-01-01

    A majority of stars are formed in open clusters, and then ejected into the Galactic field population through gravitational interactions. Therefore, understanding the internal dynamics of open clusters, through N-Body simulations, will inform the growth of the Galactic stellar population. A major input into these N-Body simulations is the frequency and mass distribution of binary star systems. Current binary detection techniques, such as radial velocity studies, are limited in depth, and therefore provide information only over a very limited mass range. As presented in the literature, different mass ranges may produce different interpretations of the observed binary population. A clearer picture of the binary population, covering a wide mass range, is needed to improve cluster simulations. We introduce a new binary detection method, Binary INformation from Open Clusters Using SEDs (BINOCS). Using newly-observed multi-wavelength photometric catalogs (0.3 - 8 micron) of the key open clusters M35, M36, M37, M67 and NGC 2420, the BINOCS method is able to determine accurate component masses for unresolved cluster binaries. We present results on the dynamical evolution of binaries from 0.4 - 2.5 M_sun within these key clusters, and explore how these results change with mass.

  18. Microbubble type and distribution dependence of focused ultrasound-induced blood-brain barrier opening.

    PubMed

    Wang, Shutao; Samiotaki, Gesthimani; Olumolade, Oluyemi; Feshitan, Jameel A; Konofagou, Elisa E

    2014-01-01

    Focused ultrasound, in the presence of microbubbles, has been used non-invasively to induce reversible blood-brain barrier (BBB) opening in both rodents and non-human primates. This study was aimed at identifying the dependence of BBB opening properties on polydisperse microbubble (all clinically approved microbubbles are polydisperse) type and distribution by using a clinically approved ultrasound contrast agent (Definity microbubbles) and in-house prepared polydisperse (IHP) microbubbles in mice. A total of 18 C57 BL/6 mice (n = 3) were used in this study, and each mouse was injected with either Definity or IHP microbubbles via the tail vein. The concentration and size distribution of activated Definity and IHP microbubbles were measured, and the microbubbles were diluted to 6 × 10(8)/mL before injection. Immediately after microbubble administration, mice were subjected to focused ultrasound with the following parameters: frequency = 1.5 MHz, pulse repetition frequency = 10 Hz, 1000 cycles, in situ peak rarefactional acoustic pressures = 0.3, 0.45 and 0.6 MPa for a sonication duration of 60 s. Contrast-enhanced magnetic resonance imaging was used to confirm BBB opening and allowed for image-based analysis. Permeability of the treated region and volume of BBB opening did not significantly differ between the two types of microbubbles (p > 0.05) at peak rarefractional acoustic pressures of 0.45 and 0.6 MPa, whereas IHP microbubbles had significantly higher permeability and opening volume (p < 0.05) at the relatively lower pressure of 0.3 MPa. The results from this study indicate that microbubble type and distribution could have significant effects on focused ultrasound-induced BBB opening at lower pressures, but less important effects at higher pressures, possibly because of the stable cavitation that governs the former. This difference may have become less significant at higher pressures, where inertial cavitation typically occurs. PMID:24239362

  19. Microbubble Type and Distribution Dependence of Focused Ultrasound Induced Blood Brain Barrier Opening

    PubMed Central

    Wang, Shutao; Samiotaki, Gesthimani; Olumolade, Oluyemi; Feshitan, Jameel A.; Konofagou, Elisa E.

    2014-01-01

    Focused Ultrasound (FUS) in the presence of microbubbles has been used to non-invasively induce reversible blood brain barrier (BBB) opening in both rodents and non-human primates. This study aims at identifying the dependence of the BBB opening properties on the polydisperse microbubble (since all clinically approved microbubbles are polydisperse) type and distribution by using clinically approved UCA (Definity®) and in-house made polydisperse microbubbles (IHP) in mice. A total of 18 C57BL/6 mice (n = 3) were used in this study, and each mouse received either Definity® or IHP microbubbles via tail vein injection. The concentration and size distribution of both the activated Definity® and IHP microbubbles were measured and diluted to 6×108/ml prior to injection. Immediately after the microbubble administration, FUS sonications were carried out with the following parameters: frequency of 1.5 MHz, pulse repetition frequency of 10 Hz, 1000 cycles, in situ peak rarefactional acoustic pressures of 0.3 MPa, 0.45 MPa, and 0.6 MPa for a sonication duration of 60 s. Contrast-enhanced magnetic resonance imaging (MRI) was used to confirm the BBB opening and allowed for image-based analysis. The permeability of the treated region and volumes of BBB opening using the two types of microbubbles did not show significant difference (P > 0.05) for PRPs of 0.45 MPa and 0.6 MPa, while IHP microbubbles showed significantly higher permeability and volume of opening (P < 0.05) at the relatively lower pressure of 0.3 MPa. The results from this study indicate that the microbubble type and distribution could have significant effects on the FUS-induced BBB opening at lower, but less important at higher, pressure levels, possibly due to the stable cavitation that governs the former. This difference may have become less significant at higher FUS pressure levels where inertial cavitation typically occurs. PMID:24239362

  20. An Open Simulation System Model for Scientific Applications

    NASA Technical Reports Server (NTRS)

    Williams, Anthony D.

    1995-01-01

    A model for a generic and open environment for running multi-code or multi-application simulations - called the open Simulation System Model (OSSM) - is proposed and defined. This model attempts to meet the requirements of complex systems like the Numerical Propulsion Simulator System (NPSS). OSSM places no restrictions on the types of applications that can be integrated at any state of its evolution. This includes applications of different disciplines, fidelities, etc. An implementation strategy is proposed that starts with a basic prototype, and evolves over time to accommodate an increasing number of applications. Potential (standard) software is also identified which may aid in the design and implementation of the system.

  1. Survey of harmonics measurements in electrical distribution systems

    Microsoft Academic Search

    Leon M. Tolbert; Harold D. Hollis

    1996-01-01

    An assessment of the harmonics found in the electrical distribution system of several buildings in the three Department of Energy (DOE) Oak Ridge plants in Tennessee has yielded several conclusions useful in the design of electrical distribution systems. A preliminary survey to determine where significant amounts of harmonic currents or voltages existed in the distribution system was performed at several

  2. 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.

  3. The need and capability of a Surveillance Data Distribution System

    Microsoft Academic Search

    D. Whitman

    2009-01-01

    The emergence of next generation technologies in Air Traffic Control (ATC) and the requirement to interface to existing sensor systems dictates the need for a Surveillance Data Distribution System (SDDS). What is a Surveillance Data Distribution System and what added capabilities does the platform offer? The distribution of surveillance data has its own unique requirements unlike the transport of generic

  4. AC versus DC distribution systems- Did we get it right?

    Microsoft Academic Search

    Hammerstrom; Donald J

    2007-01-01

    We presently enjoy a predominantly ac electrical distribution system, the engineering basis for which was designed over 100 years ago. While ac distribution systems have served us well, we should periodically pause to assess what opportunities we have accepted or been denied by the overwhelming predominance of ac electrical power distribution systems. What opportunities could be obtained by engineering dc

  5. Waiting time distribution for continuous stochastic systems

    NASA Astrophysics Data System (ADS)

    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), 10.1103/PhysRevE.86.061135]. Thus, our approach "interpolates" between these two types of stochastic motion. We illustrate our approach for both symmetric systems and systems under constant force.

  6. 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

  7. Dynamic Change Management by Distributed Graph Transformation: Towards Configurable Distributed Systems

    Microsoft Academic Search

    Gabriele Taentzer; Michael Goedicke; Torsten Meyer

    1998-01-01

    \\u000a In this contribution we consider the application of distributed graph transformation to the problem of specifying dynamic\\u000a change in distributed systems. Change in distributed systems is related to at least two levels. One is the management of change\\u000a in a local node of the distributed system and how such a local change is then propagated to those nodes which need

  8. 6.824 Distributed Computer Systems, Fall 2002

    E-print Network

    Morris, Robert Tappan

    Abstractions and implementation techniques for design of distributed systems; server design, network programming, naming, storage systems, security, and fault tolerance. Readings from current literature. 6 Engineering ...

  9. Support QoS in Open Real-Time Systems

    Microsoft Academic Search

    Zhu Xiangbin; Jinhua Zhejiang

    2008-01-01

    With the development of computer systems, the realtime systems with different kinds of real-time applications and non-real-time applications are becoming more and more popular. At the same time, more and more multimedia applications make real-time system to support QoS. Based on the real-time systems, the paper proposes a model of Linux-based open real-time systems with QoS support. Firstly, the paper

  10. Waves in Open Systems via Bi-orthogonal Basis

    E-print Network

    P. T. Leung; W. -M. Suen; C. P. Sun; K. Young

    1999-03-08

    Dissipative quantum systems are sometimes phenomenologically described in terms of a non-hermitian hamiltonian $H$, with different left and right eigenvectors forming a bi-orthogonal basis. It is shown that the dynamics of waves in open systems can be cast exactly into this form, thus providing a well-founded realization of the phenomenological description and at the same time placing these open systems into a well-known framework. The formalism leads to a generalization of norms and inner products for open systems, which in contrast to earlier works is finite without the need for regularization. The inner product allows transcription of much of the formalism for conservative systems, including perturbation theory and second-quantization.

  11. Limit of small exits in open Hamiltonian systems.

    PubMed

    Aguirre, Jacobo; Sanjuán, Miguel A F

    2003-05-01

    The nature of open Hamiltonian systems is analyzed, when the size of the exits decreases and tends to zero. Fractal basins appear typically in open Hamiltonian systems, but we claim that in the limit of small exits, the invariant sets tend to fill up the whole phase space with the strong consequence that a new kind of basin appears, where the unpredictability grows indefinitely. This means that for finite, arbitrarily small accuracy, we can find uncertain basins, where any information about the future of the system is lost. This total indeterminism had only been reported in dissipative systems, in particular in the so-called intermingled riddled basins, as well as in the riddledlike basins. We show that this peculiar, behavior is a general feature of open Hamiltonian systems. PMID:12786244

  12. Small Open Chemical Systems Theory: Its Implications to Darwinian Evolution Dynamics, Complex Self-Organization and Beyond

    NASA Astrophysics Data System (ADS)

    Qian, Hong

    2014-10-01

    The study of biological cells in terms of mesoscopic, nonequilibrium, nonlinear, stochastic dynamics of open chemical systems provides a paradigm for other complex, self-organizing systems with ultra-fast stochastic fluctuations, short-time deterministic nonlinear dynamics, and long-time evolutionary behavior with exponentially distributed rare events, discrete jumps among punctuated equilibria, and catastrophe.

  13. A Disk-Based System for Producing and Distributing Science Products from MODIS

    NASA Technical Reports Server (NTRS)

    Masuoka, Edward; Wolfe, Robert; Sinno, Scott; Ye Gang; Teague, Michael

    2007-01-01

    Since beginning operations in 1999, the MODIS Adaptive Processing System (MODAPS) has evolved to take advantage of trends in information technology, such as the falling cost of computing cycles and disk storage and the availability of high quality open-source software (Linux, Apache and Perl), to achieve substantial gains in processing and distribution capacity and throughput while driving down the cost of system operations.

  14. 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.

  15. Distributed computing in image analysis using open source frameworks and application to image sharpness assessment of histological whole slide images

    PubMed Central

    2011-01-01

    Background Automated image analysis on virtual slides is evolving rapidly and will play an important role in the future of digital pathology. Due to the image size, the computational cost of processing whole slide images (WSIs) in full resolution is immense. Moreover, image analysis requires well focused images in high magnification. Methods We present a system that merges virtual microscopy techniques, open source image analysis software, and distributed parallel processing. We have integrated the parallel processing framework JPPF, so batch processing can be performed distributed and in parallel. All resulting meta data and image data are collected and merged. As an example the system is applied to the specific task of image sharpness assessment. ImageJ is an open source image editing and processing framework developed at the NIH having a large user community that contributes image processing algorithms wrapped as plug-ins in a wide field of life science applications. We developed an ImageJ plug-in that supports both basic interactive virtual microscope and batch processing functionality. For the application of sharpness inspection we employ an approach with non-overlapping tiles. Compute nodes retrieve image tiles of moderate size from the streaming server and compute the focus measure. Each tile is divided into small sub images to calculate an edge based sharpness criterion which is used for classification. The results are aggregated in a sharpness map. Results Based on the system we calculate a sharpness measure and classify virtual slides into one of the following categories - excellent, okay, review and defective. Generating a scaled sharpness map enables the user to evaluate sharpness of WSIs and shows overall quality at a glance thus reducing tedious assessment work. Conclusions Using sharpness assessment as an example, the introduced system can be used to process, analyze and parallelize analysis of whole slide images based on open source software. PMID:21489186

  16. Guidelines for the implementation of an open source information system

    SciTech Connect

    Doak, J.; Howell, J.A.

    1995-08-01

    This work was initially performed for the International Atomic Energy Agency (IAEA) to help with the Open Source Task of the 93 + 2 Initiative; however, the information should be of interest to anyone working with open sources. The authors cover all aspects of an open source information system (OSIS) including, for example, identifying relevant sources, understanding copyright issues, and making information available to analysts. They foresee this document as a reference point that implementors of a system could augment for their particular needs. The primary organization of this document focuses on specific aspects, or components, of an OSIS; they describe each component and often make specific recommendations for its implementation. This document also contains a section discussing the process of collecting open source data and a section containing miscellaneous information. The appendix contains a listing of various providers, producers, and databases that the authors have come across in their research.

  17. Complete Positivity and Thermodynamics in a Driven Open Quantum System

    NASA Astrophysics Data System (ADS)

    Argentieri, Giuseppe; Benatti, Fabio; Floreanini, Roberto; Pezzutto, Marco

    2015-02-01

    While it is well known that complete positivity guarantees the fulfilment of the second law of thermodynamics, its possible violations have never been proposed as a check of the complete positivity of a given open quantum dynamics. We hereby consider an open quantum micro-circuit, effectively describable as a two-level open quantum system, whose asymptotic current might be experimentally accessible. This latter could indeed be used to discriminate between its possible non-completely positive Redfield dynamics and a completely positive one obtained by standard weak-coupling limit techniques, at the same time verifying the fate of the second law of thermodynamics in such a context.

  18. 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.

  19. 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’s thermal dissatisfaction below a given threshold. The DECS energy usage was calculated using the simplified thermal model. OSFA control; providing a uniform temperature to the entire building, and occupant-selected HIYW control with a thermostat at each workstation were implemented for 3 cities representing 3 different climatic regions and control scenarios. It is shown that optimization allows DECS to deliver a higher level of individual and population thermal comfort while achieving annual energy savings between 14 and 26% compared to OSFA. The optimization model also allowed us to study the influence of the partitions’ thermal resistance and the variability of internal loads at each office. These influences didn’t make significant changes in the optimized energy consumption relative to OSFA. The results show that it is possible to provide thermal comfort for each occupant while saving energy compared to OSFA Furthermore, to simplify the implementation of this approach, a fuzzy logic system has been developed to generalize the overall optimization strategy. Its performance was almost as good as the gradient system. The fuzzy system provided thermal comfort to each occupant and saved energy compared to OSFA. The energy savings of the fuzzy system were not as high as for the gradient-optimized system, but the fuzzy system avoided complete connectivity, and the optimization did not have to be repeated for each population. 3. We employed a detailed CFD model of adjacent occupied cubicles to extend the thermal-circuit model in three significant ways: (a) relax the “office wall” requirement by allowing energy to flow between zones via advection as well as conduction, (b) improve the comfort model to account both for radiation as well as convection heat transfer, and (c) support ventilation systems in which the temperature is stratified, such as in underfloor air distribution systems. Initially, three-dimensional CFD simulations of several cubicle configurations, with an adjoining corridor, were performed both to understand the advection between cubicles and the

  20. Clock distribution system for digital computers

    DOEpatents

    Wyman, Robert H. (Brentwood, CA); Loomis, Jr., Herschel H. (Davis, CA)

    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

  1. SARI OpenRec -- Empowering Recommendation Systems with Business Events

    Microsoft Academic Search

    Philip Limbeck; Martin Suntinger; Josef Schiefer

    2010-01-01

    With growing product portfolios of eCommerce companies it gets increasingly challenging for customers to find the products they like best. Current recommendation approaches primarily rely on customer-product affinities derived from explicit ratings or historical purchases. In this paper, we introduce SARI OpenRec, an extendible framework combining the capabilities of complex event processing and recommendation systems. SARI OpenRec enhances recommendations by

  2. Optimal reactive power flow with distributed generating plants in electric power distribution systems

    Microsoft Academic Search

    U. Leeton; T. Ratniyomchai; T. Kulworawanichpong

    2010-01-01

    This paper presents the solution of reactive power flow optimization for electric power distribution systems integrating with distributed generating (Distributed Generator: DG) plants which can support daily load demand. To reduce the total energy losses of the entire system, transformer tap and reactive power injection from available reactive power source are required. The setting of variables based on a particular

  3. Detection of contamination of municipal water distribution systems

    DOEpatents

    Cooper, John F. (Oakland, CA)

    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.

  4. Models and Feedback Stabilization of Open Quantum Systems

    E-print Network

    Pierre Rouchon

    2015-01-08

    At the quantum level, feedback-loops have to take into account measurement back-action. We present here the structure of the Markovian models including such back-action and sketch two stabilization methods: measurement-based feedback where an open quantum system is stabilized by a classical controller; coherent or autonomous feedback where a quantum system is stabilized by a quantum controller with decoherence (reservoir engineering). We begin to explain these models and methods for the photon box experiments realized in the group of Serge Haroche (Nobel Prize 2012). We present then these models and methods for general open quantum systems.

  5. Nonequilibrium-thermodynamics approach to open quantum systems

    NASA Astrophysics Data System (ADS)

    Semin, Vitalii; Petruccione, Francesco

    2014-11-01

    Open quantum systems are studied from the thermodynamical point of view unifying the principle of maximum informational entropy and the hypothesis of relaxation times hierarchy. The result of the unification is a non-Markovian and local-in-time master equation that provides a direct connection for dynamical and thermodynamical properties of open quantum systems. The power of the approach is illustrated by the application to the damped harmonic oscillator and the damped driven two-level system, resulting in analytical expressions for the non-Markovian and nonequilibrium entropy and inverse temperature.

  6. Indoor particle size distributions in homes with open fires and improved Patsari cook stoves

    NASA Astrophysics Data System (ADS)

    Armendáriz-Arnez, Cynthia; Edwards, Rufus D.; Johnson, Michael; Rosas, Irma A.; Espinosa, F.; Masera, Omar R.

    2010-08-01

    Particulate pollution has been clearly linked with adverse health impacts from open fire cookstoves, and indoor air concentrations are frequently used as a proxy for exposures in health studies. Implicit are the assumptions that the size distributions for the open fire and improved stove are not significantly different, and that the relationship between indoor concentrations and personal exposures is the same between stoves. To evaluate the impact of these assumptions size distributions of particulate matter in indoor air were measured with the Sioutas cascade impactor in homes using open fires and improved Patsari stoves in a rural Purepecha community in Michoacan, Mexico. On average indoor concentrations of particles less than 0.25 ?m were 72% reduced in homes with improved Patsari stoves, reflecting a reduced contribution of this size fraction to PM 2.5 mass concentrations from 68% to 48%. As a result the mass median diameter of indoor PM 2.5 particulate matter was increased by 29% with the Patsari improved stove compared to the open fire (from 0.42 ?m to 0.59 ?m, respectively). Personal PM 2.5 exposure concentrations for women in homes using open fires were approximately 61% of indoor concentration levels (156 ?g m -3 and 257 ?g m -3 respectively). In contrast personal exposure concentrations were 77% times indoor air concentration levels for women in homes using improved Patsari stoves (78 ?g m -3and 101 ?g m -3 respectively). Thus, if indoor air concentrations are used in health and epidemiologic studies significant bias may result if the shift in size distribution and the change in relationship between indoor air concentrations and personal exposure concentrations are not accounted for between different stove types.

  7. Delta3D: A Complete Open Source Game and Simulation Engine for Building Military Training Systems

    Microsoft Academic Search

    Perry McDowell; Rudolph Darken; Joe Sullivan; Erik Johnson

    2006-01-01

    Delta3D, the open source game and simulation engine built for military training, is continuing to be improved to meet the requirements of the military users. The most recent upgrades, available in versions 1.4 and later, include adding capability for After Action Review, integration with SCORM-compliant learning management systems (LMS's), and distributed interactive simulation (DIS) networking. Additionally, more applications, created by

  8. Adiabatic Charge Pumping in Open Quantum Systems JOSEPH E. AVRON

    E-print Network

    Avron, Joseph

    Adiabatic Charge Pumping in Open Quantum Systems JOSEPH E. AVRON Technion ALEXANDER ELGART Courant pumps con- nected to a number of external leads. It is proven that under the rather general assumption on the Hamiltonian describing the system, in the adiabatic limit, the current through the pump is given by a formula

  9. RESEARCH ARTICLE Open Access Sentinel surveillance system for early outbreak

    E-print Network

    Paris-Sud XI, Université de

    RESEARCH ARTICLE Open Access Sentinel surveillance system for early outbreak detection in developing a sentinel surveillance system and the well-timed information it provides for improving public, but that approach tends to be too slow for an adequate and efficient response. In fact, healthcare * Correspondence

  10. POSTER PRESENTATION Open Access Dynamics of neural systems in epilepsy

    E-print Network

    Paris-Sud XI, Université de

    POSTER PRESENTATION Open Access Dynamics of neural systems in epilepsy Kenza EL Houssaini* , Viktor 2013 Epilepsy is a nervous system disorder. It is characterized by a brain dysfunction activity in epilepsy. BMC Neuroscience 2013 14(Suppl 1):P124. * Correspondence: kenzaelhoussaini@hotmail.fr UMR 1106

  11. Control landscapes for observable preparation with open quantum systems

    SciTech Connect

    Wu Rebing; Pechen, Alexander; Rabitz, Herschel; Hsieh, Michael; Tsou, Benjamin [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)

    2008-02-15

    A quantum control landscape is defined as the observable as a function(al) of the system control variables. Such landscapes were introduced to provide a basis to understand the increasing number of successful experiments controlling quantum dynamics phenomena. This paper extends the concept to encompass the broader context of the environment having an influence. For the case that the open system dynamics are fully controllable, it is shown that the control landscape for open systems can be lifted to the analysis of an equivalent auxiliary landscape of a closed composite system that contains the environmental interactions. This inherent connection can be analyzed to provide relevant information about the topology of the original open system landscape. Application to the optimization of an observable expectation value reveals the same landscape simplicity observed in former studies on closed systems. In particular, no false suboptimal traps exist in the system control landscape when seeking to optimize an observable, even in the presence of complex environments. Moreover, a quantitative study of the control landscape of a system interacting with a thermal environment shows that the enhanced controllability attainable with open dynamics significantly broadens the range of the achievable observable values over the control landscape.

  12. An Open-Source Learning Content Management and Assessment System

    E-print Network

    LON-CAPA An Open-Source Learning Content Management and Assessment System Gerd Kortemeyer and Architecture #12;Overview LON-CAPA is a system for · Course Management, for example: posting materials Assembly Course Management LON-CAPA Architecture Shared Cross-Institutional Resource Library (Base de Dados

  13. Visitor face tracking system using OpenCV library

    Microsoft Academic Search

    Yong Kok Ching; A. S. Prabuwono; R. Sulaiman

    2009-01-01

    This paper presents the development of visitor face tracking system using OpenCV library. This system can be used for security purpose to record the visitor face. The user can identify who had been visiting him\\/her when away from the place. Visitors just need to appear in front of the web camera for at least 10 second, their image will be

  14. Study on G-M type pulse tube cryocooler with a novel active gas distribution system

    NASA Astrophysics Data System (ADS)

    Qiu, L. M.; Wang, C.; Gan, Zhihua; Dong, W. Q.

    2012-06-01

    In order to overcome the disadvantages of a traditional gas distribution system of G-M type pulse tube cryocoolers, a novel active gas distribution system with a middle stage reservoir is proposed. Different from the traditional intake and exhaust processes, the refrigeration cycle with the active gas distribution system consists of an intake process from the middle stage reservoir, an intake process from the compressor, an exhaust process to the middle stage reservoir and an exhaust process to the compressor. Theoretical analysis shows that the active distribution system may significantly reduce the power consumption of the compressor due to the reduction of irreversible losses during the intake and exhaust processes. The self-made pulse tube cooler with the active gas distribution system was tested. Experimental results show that the active gas distribution system decreases the power consumption by 27% and entropy generation by 37% when the proportion of opening time of the middle stage reservoir is 30%. The cryocooler reaches a lower refrigeration temperature with minor decrease of cooling power. Besides, the active gas distribution system may increase the life time for valves.

  15. Kernel software for efficiently building, re-configuring, and distributing an open CNC controller

    Microsoft Academic Search

    Sun-Ho Kim; Hyunbo Cho

    2006-01-01

    Several open control architectures have been proposed to enable the incorporation of new technologies into existing CNC controllers.\\u000a However, complex interfaces and communications among heterogeneous hardware and software platforms have yet to be resolved\\u000a to reduce development time and cost. We propose a piece of kernel software that facilitates the development, reconfiguration,\\u000a and distribution of CNC controllers. Assuming that various

  16. 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.

  17. 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.

  18. 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.

  19. Complex network analysis of water distribution systems

    NASA Astrophysics Data System (ADS)

    Yazdani, Alireza; Jeffrey, Paul

    2011-03-01

    This paper explores a variety of strategies for understanding the formation, structure, efficiency, and vulnerability of water distribution networks. Water supply systems are studied as spatially organized networks for which the practical applications of abstract evaluation methods are critically evaluated. Empirical data from benchmark networks are used to study the interplay between network structure and operational efficiency, reliability, and robustness. Structural measurements are undertaken to quantify properties such as redundancy and optimal-connectivity, herein proposed as constraints in network design optimization problems. The role of the supply demand structure toward system efficiency is studied, and an assessment of the vulnerability to failures based on the disconnection of nodes from the source(s) is undertaken. The absence of conventional degree-based hubs (observed through uncorrelated nonheterogeneous sparse topologies) prompts an alternative approach to studying structural vulnerability based on the identification of network cut-sets and optimal-connectivity invariants. A discussion on the scope, limitations, and possible future directions of this research is provided.

  20. Interpreting Distributed System Architectures using VDM++ - A Case Study

    Microsoft Academic Search

    Marcel Verhoef; Peter Gorm Larsen

    2007-01-01

    The complexity of real-time embedded systems is increasing in particular due to the use of distributed system architectures for their implementation. Notations to describe these software intensive distributed computer systems at the system-level are at best still in their infancy. An extension to the Vienna Development Method (VDM) is proposed to address the problem of analyzing deployment of software on

  1. Software Defect Masquerade Faults in Distributed Embedded Systems 1.Introduction

    E-print Network

    Koopman, Philip

    Software Defect Masquerade Faults in Distributed Embedded Systems 1.Introduction Distributed embedded systems often consist of multiple nodes that communicate over a shared network. For such systems or process to send a message as having come from another node or process. Unfortunately, many embedded system

  2. DAISY: An Object-Oriented System for Distributed Artificial Intelligence

    Microsoft Academic Search

    Agostino Poggi

    1994-01-01

    This paper presents an object-oriented distributed system, called DAISY, for the development and experimentation of Distributed Artificial Intelligence systems and algorithms. This system is based on two programming levels: object level and agent level. Both the levels allow to define, implement and experiment systems. While the object level offers a large set of low level programming means (a large set

  3. Metric (Extended Abstract): A kernel instrumentation system for distributed environments

    Microsoft Academic Search

    Gene Mcdaniel

    1977-01-01

    Metric is a distributed software measurement system that communicates measurement data over the PARC computer network, the Ethernet. Metric is used to instrument stand alone and distributed computer systems (it works in an environment of about 90 machines total and is used by about 15 machines). The system is divided into three parts: object system probes that transmit measurement events,

  4. The Information Bus - An Architecture for Extensible Distributed Systems

    Microsoft Academic Search

    Brian M. Oki; Manfred Pfluegl; Alex Siegel; Dale Skeen

    1993-01-01

    Research can rarely be performed on large-scale, distributed systems at the level of thousands of workstations. In this paper, we describe the motivating constraints, design principles, and architecture for an extensible, distributed system operating in such an environment. The constraints include continuous operation, dynamic system evolution, and integration with extant systems. The , our solution, is a novel synthesis of

  5. Exceptional points in open and PT symmetric systems

    E-print Network

    Hichem Eleuch; Ingrid Rotter

    2014-04-29

    Exceptional points (EPs) determine the dynamics of open quantum systems and cause also PT symmetry breaking in PT symmetric systems. From a mathematical point of view, this is caused by the fact that the phases of the wavefunctions (eigenfunctions of a non-Hermitian Hamiltonian) relative to one another are not rigid when an EP is approached. The system is therefore able to align with the environment to which it is coupled and, consequently, rigorous changes of the system properties may occur. We compare analytically as well as numerically the eigenvalues and eigenfunctions of a $2\\times 2$ matrix that is characteristic of either open quantum systems at high level density or of PT symmetric optical lattices. In both cases, the results show clearly the influence of the environment onto the system in the neighborhood of EPs. Although the systems are very different from one another, the eigenvalues and eigenfunctions indicate the same characteristic features.

  6. Pressure Control for Leakage Minimisation in Water Distribution Systems Management

    Microsoft Academic Search

    L. S. Araujo; H. Ramos; S. T. Coelho

    2006-01-01

    A model to support decision systems regarding the quantification, location and opening adjustment of control valves in a network\\u000a system, with the main objective to minimise pressures and consequently leakage levels is developed. This research work aims\\u000a at a solution that allows simultaneously optimising the number of valves and its location, as well as valves opening adjustments\\u000a for simulation in

  7. STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE

    E-print Network

    STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE MECH-14A NA7.5.13 Distributed Energy Storage DX AC DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION

  8. 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...

  9. AC versus DC distribution systems- Did we get it right?

    SciTech Connect

    Hammerstrom, Donald J.

    2007-06-28

    We presently enjoy a predominantly ac electrical distribution system, the engineering basis for which was designed over 100 years ago. While ac distribution systems have served us well, we should periodically pause to assess what opportunities we have accepted or been denied by the overwhelming predominance of ac electrical power distribution systems. What opportunities could be obtained by engineering dc distribution into at least portions of our present system? What advantages of the present ac distribution system should be recognized and protected? This paper will focus on distribution within premise and low-voltage distribution systems. Specifically, we will address the conversion efficiency costs of adopting various premise ac and dc distribution system topologies. According to a simple predictive model formulated in this paper, premise residential dc distribution will incur unfavorable total conversion efficiency compared with existing ac premise distribution. However, if a residence is supplied by a fuel cell or another dc generator, the total conversion efficiency within a residential dc distribution system could be similar to, or even better than, that for ac distribution.

  10. Equilibrium states of open quantum systems in the strong coupling regime.

    PubMed

    Suba??, Y; Fleming, C H; Taylor, J M; Hu, B L

    2012-12-01

    In this work we investigate the late-time steady states of open quantum systems coupled to a thermal reservoir in the strong coupling regime. In general such systems do not necessarily relax to a Boltzmann distribution if the coupling to the thermal reservoir is nonvanishing or equivalently if the relaxation time scales are finite. Using a variety of nonequilibrium formalisms valid for non-Markovian processes, we show that starting from a product state of the closed system = system+environment, with the environment in its thermal state, the open system which results from coarse graining the environment will evolve towards an equilibrium state at late times. This state can be expressed as the reduced state of the closed system thermal state at the temperature of the environment. For a linear (harmonic) system and environment, which is exactly solvable, we are able to show in a rigorous way that all multitime correlations of the open system evolve towards those of the closed system thermal state. Multitime correlations are especially relevant in the non-Markovian regime, since they cannot be generated by the dynamics of the single-time correlations. For more general systems, which cannot be exactly solved, we are able to provide a general proof that all single-time correlations of the open system evolve to those of the closed system thermal state, to first order in the relaxation rates. For the special case of a zero-temperature reservoir, we are able to explicitly construct the reduced closed system thermal state in terms of the environmental correlations. PMID:23367918

  11. Bluetooth Enabled Interaction in a Distributed Camera Surveillance System

    Microsoft Academic Search

    Peter Rigole; Yolande Berbers; Tom Holvoet

    2004-01-01

    This paper reports on the challenge to extend an ex- isting distributed camera surveillance security applica- tion with Bluetooth driven wireless communication using handheld PC's. The main focus is on the engineering as- pect of the development of BlueGuard. The paper gives an in-depth assessment of the chosen open software used and the choices made, on how Bluetooth support was

  12. I 5 : A FRAMEWORK FOR ARCHITECTURAL SPECIFICATION OF DISTRIBUTED SYSTEMS

    E-print Network

    Demurjian, Steven A.

    . Keywords: Distributed software engineering, formal specification language, software architectureI 5 : A FRAMEWORK FOR ARCHITECTURAL SPECIFICATION OF DISTRIBUTED SYSTEMS M. CECILIA BASTARRICA and specification tasks. A unifying architectural specifica­ tion framework can be a valuable tool for organizing

  13. : A FRAMEWORK FOR ARCHITECTURAL SPECIFICATION OF DISTRIBUTED SYSTEMS

    E-print Network

    Demurjian, Steven A.

    : Distributed software engineering, formal specification language, software architecture, configuration ¢¡ : A FRAMEWORK FOR ARCHITECTURAL SPECIFICATION OF DISTRIBUTED SYSTEMS M. CECILIA BASTARRICA and specification tasks. A unifying architectural specifica- tion framework can be a valuable tool for organizing

  14. Harmonic impact of different distributed generation units on low voltage distribution system

    Microsoft Academic Search

    A. F. Abdul Kadir; A. Mohamed; H. Shareef

    2011-01-01

    This paper is concerned with harmonic impact of different types of distributed generation (DG) units in low voltage distribution systems. This study considers the impact of three types of DG units connected to a power system, a mini hydro synchronous generator, photovoltaic system and double fed induction generator wind turbine. The DG units are modelled using the PSCAD\\/EMTDC program and

  15. Lessons learned in transitioning to an open systems environment

    NASA Technical Reports Server (NTRS)

    Boland, Dillard E.; Green, David S.; Steger, Warren L.

    1994-01-01

    Software development organizations, both commercial and governmental, are undergoing rapid change spurred by developments in the computing industry. To stay competitive, these organizations must adopt new technologies, skills, and practices quickly. Yet even for an organization with a well-developed set of software engineering models and processes, transitioning to a new technology can be expensive and risky. Current industry trends are leading away from traditional mainframe environments and toward the workstation-based, open systems world. This paper presents the experiences of software engineers on three recent projects that pioneered open systems development for NASA's Flight Dynamics Division of the Goddard Space Flight Center (GSFC).

  16. DEVELOPMENT OF A SORBENT DISTRIBUTION AND RECOVERY SYSTEM

    EPA Science Inventory

    This report describes the design, fabrication, and test of a prototype system for the recovery of spilled oil from the surface of river, estuarine, and harbor waters. The system utilizes an open cell polyurethane foam in small cubes to absorb the floating oil. The system is highl...

  17. Second law study of HVAC distribution system performance

    SciTech Connect

    Franconi, E.M.; Brandemuehl, M.J.

    1999-07-01

    In this study, the performance of two HVAC distribution systems is evaluated using the first and second laws of thermodynamics. The constant-air-volume (CAV) and variable-air-volume (VAV) systems are modeled using the TRNSYS simulation program. A first law analysis is used to investigate the relationship between building loads, distribution system loads, and plant energy consumption. A combined law analysis is completed to determine exergy flows and the useful work depleted by system components. To measure distribution system design advancements, the second law efficiencies of the two systems are compared. Applications of exergy analysis for making better informed operation and maintenance (O and M) decisions are also explored. In one application, an exergy analysis is used to quantify the thermodynamic effect of a VAV system malfunction. The other investigates how well distribution system exergy can be used to identify distribution system controller set points that minimize plant energy consumption.

  18. Geomorphic elements on modern distributive fluvial systems

    NASA Astrophysics Data System (ADS)

    Davidson, Stephanie K.; Hartley, Adrian J.; Weissmann, Gary S.; Nichols, Gary J.; Scuderi, Louis A.

    2013-01-01

    Analysis of over 400 fluvial megafans (> 30 km in length) in aggradational continental sedimentary basins reveals that geomorphic channel and floodplain changes on these distributive fluvial systems (DFS) generally behave in predictable ways with increasing distance from the apex. These changes can include: a decrease in discharge, a decrease in bed material transport and calibre of sediment, a decrease in stream power, an overall decrease in channel width, an overall decrease in channel depth, an increase in avulsive behaviour, and sinuosity becomes more variable. Three generic geomorphic element models are proposed - reflecting observed changes in channel behaviour - based on measurable changes in channel width and planform characteristics with increasing distance downstream. The three models are derived from (1) a single braided channel that bifurcates downstream into low sinuosity channels; (2) a dominant, sinuous, single-thread channel that anabranches and bifurcates with distance downstream, creating smaller channels with varying sinuosity; and (3) a dominant multi-thread channel that anabranches and bifurcates with distance downstream, creating smaller channels with varying sinuosity. The changes in fluvial behaviour and landforms on DFS are in response to variable discharge and sediment supply ratios from the upstream catchment. In contrast to examples described in hydrogeomorphological literature for tributary fluvial systems where channel dimensions tend to increase downstream, observations from DFS suggest that - where the formative DFS channel does not retain the same dimensions - intrinsic geomorphic thresholds lead to the breakdown of the main trunk channel into smaller anabranching and distributary channels with distance downstream; in some instances the majority of channelised flow at the DFS termination may even be disintegrated. The observed range of termination types and floodplain soils for each DFS type are interchangeable dependent on local conditions. The modern geomorphic elements and floodplain soils are dependent on climate in the upstream catchment and in the downstream receiving sedimentary basin.

  19. 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)

  20. 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...

  1. A distributed slack bus model and its impact on distribution system application techniques

    Microsoft Academic Search

    Shiqiong Tong; Michael Kleinberg; Karen Miu

    2005-01-01

    Distribution system operating environments are changing rapidly. For example, with the steady and significant increase in dispersed generation expected, planning and operating application techniques must also change. This paper re-evaluates the single slack bus assumption typically employed in steady-state distribution power flow solvers. Specifically, a distributed slack bus model based on the concept of generator domains will be discussed and

  2. Investigation and Comparison of Distributed NoSQL Database Systems

    E-print Network

    Investigation and Comparison of Distributed NoSQL Database Systems Xiaoming Gao Indiana University This report investigates and compares four representative distributed NoSQL database systems, including HBase application by a NoSQL database system. 1.1 HBase HBase supports the BigTable data model [1

  3. 1 Research Group on Computer Networks and Distributed Systems

    E-print Network

    Sola, Rolf Haenni

    design for embedded networked devices Data gathering, either for event recognition or for monitoring1 Research Group on Computer Networks and Distributed Systems 1.1 Personnel Head: Prof. Dr. T for Computer Networks and Distributed Systems (Rechnernetze und Verteilte Systeme, RVS) has been active since

  4. A Wireless Distributed Wall Climbing Robotic System for Reconnaissance Purpose

    Microsoft Academic Search

    Shanqiang Wu; Mantian Li; Shu Xiao; Yang Li

    2006-01-01

    The paper proposes a wireless distributed wall climbing robotic system for reconnaissance purpose. Firstly, we introduce the mechanism of the distributed wall climbing robotic system. The mother wall-climbing robot of one single suction cup with two wheels locomotion system enables fast motion and can adapt nearly any kind of vertical wall surface in urban environment. The child wall climbing robot

  5. 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.

  6. Mobile Agent Attack Resistant Distributed Hierarchical Intrusion Detection Systems

    Microsoft Academic Search

    Peter Mell; Mark Mclarnon

    1999-01-01

    Distributed intrusion detection systems are especially vulnerable to attacks since, typically, each component resides at a static location and components are connected together into a hierarchical structure. An attacker can disable such a system by taking out a node high in the hierarchy, thus amputating a portion of the distributed system. A solution to this problem is to cast the

  7. Performance estimation for real-time distributed embedded systems

    Microsoft Academic Search

    Ti-yen Yen; Wayne Wolf

    1995-01-01

    Many embedded computing systems are distributed systems: communicating processes executing on several CPUs\\/ASICs connected by communication links. This paper describes a new, efficient analysis algorithm to derive tight bounds on the execution time required for an application task executing on a distributed system. Tight bounds are essential to cosynthesis algorithms. Our bounding algorithms are valid for a general problem model:

  8. Teaching distribution system reliability evaluation using Monte Carlo simulation

    Microsoft Academic Search

    R. Billinton; Peng Wang

    1999-01-01

    Analytical techniques for distribution system reliability assessment can be effectively used to evaluate the mean values of a wide range of system reliability indices. This approach is usually used when teaching the basic concepts of distribution system reliability evaluation. The mean or expected value, however, does not provide any information on the inherent variability of an index. Appreciation of this

  9. Design of distributed control system for Malakoff Generating Station

    Microsoft Academic Search

    A. M. Romano; F. Chin; R. D. Simpson; J. A. Rovnak

    1984-01-01

    Microprocessor-based distributed control technology can provide increased reliability and flexibility, and together with an integrated operator interface promises better plant efficiency and availability. An overview of the procedure followed in engineering a distributed digital control system with an integrated operator interface for a large lignite-fired generating plant is presented. The system includes Boiler and Burner control, Interposing Logic System and

  10. A Distributed Camera System for Multi-Resolution Surveillance

    E-print Network

    Oxford, University of

    A Distributed Camera System for Multi-Resolution Surveillance Nicola Bellotto, Eric Sommerlade, Ben for a multi-camera, multi-resolution surveillance system. The aim is to support a set of distributed static. To this end we describe an architecture for a multi-camera, multi- resolution surveillance system

  11. Flight plan management in a distributed air traffic control system

    Microsoft Academic Search

    P. Queinnec; Gdrard Padiou

    1993-01-01

    The authors explore how large-scale replication can enhance the availability of data in a loosely coupled distributed system. The concern is with air traffic control systems that are geographically distributed and impose strict constraints of availability. In this framework, a replication system providing a weak consistency of data is proposed. The specific properties of flight plan data are studied, and

  12. Open Rotor Tone Shielding Methods for System Noise Assessments Using Multiple Databases

    NASA Technical Reports Server (NTRS)

    Bahr, Christopher J.; Thomas, Russell H.; Lopes, Leonard V.; Burley, Casey L.; Van Zante, Dale E.

    2014-01-01

    Advanced aircraft designs such as the hybrid wing body, in conjunction with open rotor engines, may allow for significant improvements in the environmental impact of aviation. System noise assessments allow for the prediction of the aircraft noise of such designs while they are still in the conceptual phase. Due to significant requirements of computational methods, these predictions still rely on experimental data to account for the interaction of the open rotor tones with the hybrid wing body airframe. Recently, multiple aircraft system noise assessments have been conducted for hybrid wing body designs with open rotor engines. These assessments utilized measured benchmark data from a Propulsion Airframe Aeroacoustic interaction effects test. The measured data demonstrated airframe shielding of open rotor tonal and broadband noise with legacy F7/A7 open rotor blades. Two methods are proposed for improving the use of these data on general open rotor designs in a system noise assessment. The first, direct difference, is a simple octave band subtraction which does not account for tone distribution within the rotor acoustic signal. The second, tone matching, is a higher-fidelity process incorporating additional physical aspects of the problem, where isolated rotor tones are matched by their directivity to determine tone-by-tone shielding. A case study is conducted with the two methods to assess how well each reproduces the measured data and identify the merits of each. Both methods perform similarly for system level results and successfully approach the experimental data for the case study. The tone matching method provides additional tools for assessing the quality of the match to the data set. Additionally, a potential path to improve the tone matching method is provided.

  13. Greenhouse Gas Emission Analysis for Distributed Energy System

    Microsoft Academic Search

    Zhai Rong-rong; Yang Yong-ping; Duan Li-qiang

    2008-01-01

    Greenhouse effect directly affects human health. The literature firstly introduces greenhouse effect and the distributed energy system. Four systems including one natural gas micro-turbine system, one internal combustion biogas engine system, one Phosphoric Acid Fuel Cell combined heat and power system and one Proton Exchange Membrane Fuel Cell system are taken as the targets. Greenhouse gas concentration and emission rate

  14. Ibis: A Programming System for Real-World Distributed Computing

    Microsoft Academic Search

    Henri E. Bal

    2009-01-01

    The landscape of distributed computing systems has changed many times over the previous decades. Modern real-world distributed\\u000a systems consist of clusters, grids, clouds, desktop grids, and mobile devices. Writing applications for such systems has become\\u000a increasingly difficult. The aim of the Ibis project is to drastically simplify the programming of such applications. The Ibis\\u000a philosophy is that real-world distributed applications

  15. Developing an Open Source, Reusable Platform for Distributed Collaborative Information Management in the Early Detection Research Network

    NASA Technical Reports Server (NTRS)

    Hart, Andrew F.; Verma, Rishi; Mattmann, Chris A.; Crichton, Daniel J.; Kelly, Sean; Kincaid, Heather; Hughes, Steven; Ramirez, Paul; Goodale, Cameron; Anton, Kristen; Colbert, Maureen; Downs, Robert R.; Patriotis, Christos; Srivastava, Sudhir

    2012-01-01

    For the past decade, the NASA Jet Propulsion Laboratory, in collaboration with Dartmouth University has served as the center for informatics for the Early Detection Research Network (EDRN). The EDRN is a multi-institution research effort funded by the U.S. National Cancer Institute (NCI) and tasked with identifying and validating biomarkers for the early detection of cancer. As the distributed network has grown, increasingly formal processes have been developed for the acquisition, curation, storage, and dissemination of heterogeneous research information assets, and an informatics infrastructure has emerged. In this paper we discuss the evolution of EDRN informatics, its success as a mechanism for distributed information integration, and the potential sustainability and reuse benefits of emerging efforts to make the platform components themselves open source. We describe our experience transitioning a large closed-source software system to a community driven, open source project at the Apache Software Foundation, and point to lessons learned that will guide our present efforts to promote the reuse of the EDRN informatics infrastructure by a broader community.

  16. 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.

  17. RFID based production and distribution management systems for home appliance industry

    Microsoft Academic Search

    Xubing Chen; Yuhui Wang; Zhouping Yin

    2010-01-01

    The goal of the paper is to provide RFID based management methodologies for the production and distribution processes in the life cycle management of home appliances. Major hardware components and software functions of the process management systems are described as a combination case of closed-loop and open-loop applications. For the closed-loop application in factories, HF RFID tray tags, workstation readers

  18. Sensor Networks for Monitoring and Control of Water Distribution Systems

    E-print Network

    Whittle, Andrew

    Water distribution systems present a significant challenge for structural monitoring. They comprise a complex network of pipelines buried underground that are relatively inaccessible. Maintaining the integrity of these ...

  19. Multimedia Courseware in an Open Systems Environment: A Federal Strategy.

    ERIC Educational Resources Information Center

    Moline, Judi; And Others

    The Portable Courseware Project (PORTCO) of the U.S. Department of Defense (DoD) is typical of projects worldwide that require standard software interfaces. This paper articulates the strategy whereby the federal multimedia courseware initiative leverages the open systems movement and the new realities of information technology. The federal…

  20. Current research information systems, open access repositories and libraries : ANTAEUS

    Microsoft Academic Search

    Nicholas Joint

    2008-01-01

    Purpose – The purpose of this paper is to give an overview of larger developments in the international research information environment, and to outline their impact on the open access movement within libraries. Design\\/methodology\\/approach – A narrative account of recent historical developments such as national current research information systems (CRIS), and their local campus equivalents, together with an analysis of

  1. ROADMAP: extending the gaia methodology for complex open systems

    Microsoft Academic Search

    Thomas Juan; Adrian R. Pearce; Leon Sterling

    2002-01-01

    This paper is concerned with improving the software engineering of agent-based open systems. It critiques the existing Gaia methodology in the light of a motivating example of intelligent home networks. It describes the ROADMAP1 methodology, which extends Gaia with four improvements - formal models of knowledge and the environment, role hierarchies, explicit representation of social structures and relationships, and incorporation

  2. Evolution Patterns of Open-Source Software Systems and Communities

    E-print Network

    Nakakoji, Kumiyo

    Evolution Patterns of Open-Source Software Systems and Communities Kumiyo Nakakoji1,2,3 Yasuhiro product evolution". To understand how this "natural product evolution" happens, we have conducted a case study of four typical OSS projects. Unlike most previous studies on software evolution that focus

  3. A Case Study in Hardware-Software Codesign of Distributed Systems - Vehicle Parking Management System

    Microsoft Academic Search

    Trong-yen Lee; Pao-ann Hsiung; Sao-jie Chen

    1999-01-01

    Hardware-software codesign of distributed systems is a more challenging task than that of centralized embedded systems. Each phase of codesign, such as copartitioning, cosynthesis, cosimulation, and coverification, must take into account physical restrictions imposed by the distributed nature of such systems. Although codesign of distributed systems is more complex, yet many common parts of the systems can be reused for

  4. Distributed Information System for Dynamic Ocean Data in Indonesia

    NASA Astrophysics Data System (ADS)

    Romero, Laia; Sala, Joan; Polo, Isabel; Cases, Oscar; López, Alejandro; Jolibois, Tony; Carbou, Jérome

    2014-05-01

    Information systems are widely used to enable access to scientific data by different user communities. MyOcean information system is a good example of such applications in Europe. The present work describes a specific distributed information system for Ocean Numerical Model (ONM) data in the scope of the INDESO project, a project focused on Infrastructure Development of Space Oceanography in Indonesia. INDESO, as part of the Blue Revolution policy conducted by the Indonesian government for the sustainable development of fisheries and aquaculture, presents challenging service requirements in terms of services performance, reliability, security and overall usability. Following state-of-the-art technologies on scientific data networks, this robust information system provides a high level of interoperability of services to discover, view and access INDESO dynamic ONM scientific data. The entire system is automatically updated four times a day, including dataset metadata, taking into account every new file available in the data repositories. The INDESO system architecture has been designed in great part around the extension and integration of open-source flexible and mature technologies. It involves three separate modules: web portal, dissemination gateway, and user administration. Supporting different gridded and non-gridded data, the INDESO information system features search-based data discovery, data access by temporal and spatial subset extraction, direct download and ftp, and multiple-layer visualization of datasets. A complex authorization system has been designed and applied throughout all components, in order to enable services authorization at dataset level, according to the different user profiles stated in the data policy. Finally, a web portal has been developed as the single entry point and standardized interface to all data services (discover, view, and access). Apache SOLR has been implemented as the search server, allowing faceted browsing among ocean data products and the connection to an external catalogue of metadata records. ncWMS and Godiva2 have been the basis of the viewing server and client technologies developed, MOTU has been used for data subsetting and intelligent management of data queues, and has allowed the deployment of a centralised download interface applicable to all ONM products. Unidata's Thredds server has been employed to provide file metadata and remote access to ONM data. CAS has been used as the single sign-on protocol for all data services. The user management application developed has been based on GOSA2. Joomla and Bootstrap have been the technologies used for the web portal, compatible with mobile phone and tablet devices. The INDESO information system comes up as an information system that is scalable, extremely easy to use, operate and maintain. This will facilitate the extensive use of ocean numerical model data by the scientific community in Indonesia. Constituted mostly of open-source solutions, the system is able to meet strict operational requirements, and carry out complex functions. It is feasible to adapt this architecture to different static and dynamic oceanographic data sources and large data volumes, in an accessible, fast, and comprehensive manner.

  5. Distributed embedded computing systems are special-purpose computer systems designed for particular applications and set up in a networked or distributed manner. A

    E-print Network

    Bhattacharyya, Shuvra S.

    of architectures, applications, and methodologies for distributed embedded systems will be covered by addressingABSTRACT Distributed embedded computing systems are special-purpose computer systems designed representations of distributed embedded applications into system implementations. This thesis is also concerned

  6. International Journal of Artificial Intelligence in Education (1998), 9, 256-274 A Framework System for Intelligent Support in Open

    E-print Network

    Paris-Sud XI, Université de

    International Journal of Artificial Intelligence in Education (1998), 9, 256-274 256 A Framework2007 Author manuscript, published in "International Journal of Artificial Intelligence in Education System for Intelligent Support in Open Distributed Learning Environments M. Mühlenbrock, F. Tewissen, H

  7. Open-frame system for single-molecule microscopy

    NASA Astrophysics Data System (ADS)

    Arsenault, Adriel; Leith, Jason S.; Henkin, Gil; McFaul, Christopher M. J.; Tarling, Matthew; Talbot, Richard; Berard, Daniel; Michaud, Francois; Scott, Shane; Leslie, Sabrina R.

    2015-03-01

    We present the design and construction of a versatile, open frame inverted microscope system for wide-field fluorescence and single molecule imaging. The microscope chassis and modular design allow for customization, expansion, and experimental flexibility. We present two components which are included with the microscope which extend its basic capabilities and together create a powerful microscopy system: A Convex Lens-induced Confinement device provides the system with single-molecule imaging capabilities, and a two-color imaging system provides the option of imaging multiple molecular species simultaneously. The flexibility of the open-framed chassis combined with accessible single-molecule, multi-species imaging technology supports a wide range of new measurements in the health, nanotechnology, and materials science research sectors.

  8. 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.

  9. An Open-source Meteorological Operational System and its Installation in Portuguese- speaking Countries

    NASA Astrophysics Data System (ADS)

    Almeida, W. G.; Ferreira, A. L.; Mendes, M. V.; Ribeiro, A.; Yoksas, T.

    2007-05-01

    CPTEC, a division of Brazil’s INPE, has been using several open-source software packages for a variety of tasks in its Data Division. Among these tools are ones traditionally used in research and educational communities such as GrADs (Grid Analysis and Display System from the Center for Ocean-Land-Atmosphere Studies (COLA)), the Local Data Manager (LDM) and GEMPAK (from Unidata), andl operational tools such the Automatic File Distributor (AFD) that are popular among National Meteorological Services. In addition, some tools developed locally at CPTEC are also being made available as open-source packages. One package is being used to manage the data from Automatic Weather Stations that INPE operates. This system uses only open- source tools such as MySQL database, PERL scripts and Java programs for web access, and Unidata’s Internet Data Distribution (IDD) system and AFD for data delivery. All of these packages are get bundled into a low-cost and easy to install and package called the Meteorological Data Operational System. Recently, in a cooperation with the SICLIMAD project, this system has been modified for use by Portuguese- speaking countries in Africa to manage data from many Automatic Weather Stations that are being installed in these countries under SICLIMAD sponsorship. In this presentation we describe the tools included-in and and architecture-of the Meteorological Data Operational System.

  10. 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.

  11. Formal Development and Verification of a Distributed Railway Control System

    Microsoft Academic Search

    Anne Elisabeth Haxthausen; Jan Peleska

    2000-01-01

    The authors introduce the concept for a distributed railway control system and present the specification and verification of the main algorithm used for safe distributed control. Our design and verification approach is based on the RAISE method, starting with highly abstract algebraic specifications which are transformed into directly implementable distributed control processes by applying a series of refinement and verification

  12. Ceph: A Scalable, High-Performance Distributed File System

    Microsoft Academic Search

    Sage A. Weil; Scott A. Brandt; Ethan L. Miller; Darrell D. E. Long; Carlos Maltzahn

    2006-01-01

    We have developed Ceph, a distributed file system that provides excellent performance, reliability, and scala- bility. Ceph maximizes the separation between data and metadata management by replacing allocation ta- bles with a pseudo-random data distribution function (CRUSH) designed for heterogeneous and dynamic clus- ters of unreliable object storage devices (OSDs). We leverage device intelligence by distributing data replica - tion,

  13. Evolution of an open system as a continuous measurement of this system by its environment

    E-print Network

    Mensky, M B

    2003-01-01

    The restricted-path-integral (RPI) description of a continuous quantum measurement is rederived starting from the description of an open system by the Feynman-Vernon influence functional. For this end the total evolution operator of the compound system consisting of the open system and its environment is decomposed into the sum of partial evolution operators. Accordingly, the influence functional of the open system is decomposed into the integral of partial influence functionals (PIF). If the partial evolution operators or PIF are chosen in such a way that they decohere (do not interfere with each other), then the formalism of RPI effectively arises. The evolution of the open system may then be interpreted as a continuous measurement of this system by its environment. This is possible if the environment is macroscopic or mesoscopic.

  14. Evolution of an open system as a continuous measurement of this system by its environment

    E-print Network

    Michael B. Mensky

    2002-11-19

    The restricted-path-integral (RPI) description of a continuous quantum measurement is rederived starting from the description of an open system by the Feynman-Vernon influence functional. For this end the total evolution operator of the compound system consisting of the open system and its environment is decomposed into the sum of partial evolution operators. Accordingly, the influence functional of the open system is decomposed into the integral of partial influence functionals (PIF). If the partial evolution operators or PIF are chosen in such a way that they decohere (do not interfere with each other), then the formalism of RPI effectively arises. The evolution of the open system may then be interpreted as a continuous measurement of this system by its environment. This is possible if the environment is macroscopic or mesoscopic.

  15. Modeling and performance analysis of fuzzy based distributed generation supported distribution system

    Microsoft Academic Search

    S. S. Darly; P. Vanaja Ranjan; K. V. Bindu; A. Srikrishnan; P. R. Krishnan; B. J. Rabi

    2010-01-01

    The traditional approach in an electrical power system is to have centralized large capacity power plants feeding power to distant load centers through an extensive transmission and distribution network. DG emerged as an alternative to upgrade transmission lines and increase the capacity of remote power plants. The connection of DG to a Distribution system meets the various challenges like power

  16. Biometrics Authentication System on Open Network and Security Analysis

    Microsoft Academic Search

    Zhenhua Wu

    2008-01-01

    Biometrics-based authentication systems are being increasingly used to control physical access to high-security facilities. In the case of biometrics authentication through an open network, there are many vulnerabilities which need to be addressed. After analyzing the possible vulnerabilities of a biometrics-based network authentication system, this paper presents a biometrics-based network authentication model combined with public key encryption technology to guarantee

  17. Distillation of Bell states in open systems

    SciTech Connect

    Isasi, E.; Mundarain, D. [Departamento de Fisica, Seccion de Fenomenos Opticos, Universidad Simon Bolivar, Apartado Postal 89000, Caracas 1080A (Venezuela, Bolivarian Republic of)

    2010-04-15

    In this work we show that the distillation protocol proposed by P. Chen et al. [Phys. Rev. A 54, 3824 (1996)] allows one to distill Bell states at any time for a system evolving in vacuum and prepared in an initial singlet. It is also shown that the same protocol, applied in nonzero temperature thermal baths, yields a considerable recovering of entanglement.

  18. An Open-System Model of Learning.

    ERIC Educational Resources Information Center

    Winn, William

    In view of the apparent complexity and dynamism of the learner, only a systems approach to learning processes can provide a viable and practical frame of reference within which to conduct educational research. There are fundamental weaknesses in the current cybernetic model of learning, and therefore, it is useful to consider the learner as an…

  19. Visualizing Power System Operationsin an Open Market

    E-print Network

    Gross, George

    in this article is; designed for the many new players in the power industry who will never operate an actual sys. Laufenberg",and Peter IM SauerI 1 he electric utility industry is undergoing a very turbulent peri- od in a revamping of the way power systems operate and the way power industry players are structured. These changes

  20. Statistics of resonance states in open chaotic systems: a perturbative approach.

    PubMed

    Poli, Charles; Savin, Dmitry V; Legrand, Olivier; Mortessagne, Fabrice

    2009-10-01

    We investigate the statistical properties of the complexness parameter which characterizes uniquely complexness (nonorthogonality) of resonance eigenstates of open chaotic systems. Specifying to the regime of weakly overlapping resonances, we apply the random matrix theory to the effective Hamiltonian formalism and derive analytically the probability distribution of the complexness parameter for two statistical ensembles describing the systems invariant under time reversal. For those with rigid spectra, we consider a Hamiltonian characterized by a picket-fence spectrum without spectral fluctuations. Then, in the more realistic case of a Hamiltonian described by the Gaussian orthogonal ensemble, we reveal and discuss the role of spectral fluctuations. PMID:19905411

  1. Substream Trading: Towards an Open P2P Live Streaming System

    E-print Network

    Panwar, Shivendra S.

    Substream Trading: Towards an Open P2P Live Streaming System Zhengye Liu, Yanming Shen, Keith W the design of an open P2P live-video streaming system. When designing a live video system that is both open and P2P, the system must include mechanisms that incentivize peers to contribute upload capacity. We

  2. Open Giant Intelligent Information Systems and Its Agent-Oriented Abstraction Mechanism

    E-print Network

    Cao, Longbing

    , and build an open giant intelligent information system, which is actually a human-computer- cooperatedOpen Giant Intelligent Information Systems and Its Agent-Oriented Abstraction Mechanism Longbing intelligent information systems, an open giant intelligent information system is a special kind of complex

  3. 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...

  4. 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...

  5. Open-architecture system based on a reconfigurable hardware-software multi-agent platform for CNC machines

    Microsoft Academic Search

    Luis Morales-Velazquez; René de Jesús Romero-Troncoso; Roque Alfredo Osornio-Rios; Gilberto Herrera-Ruiz; Eduardo Cabal-Yepez

    2010-01-01

    New generation of manufacturing systems endows their intelligence and reconfigurability to the computerized numerical controller (CNC) machines. This paper presents an open-architecture platform based on multi-agent hardware–software units, by developing a novel Multi-Agent Distributed CONtroller (MADCON) system. This system intends to fulfill the requirements of reconfigurability for the next generation of intelligent machines. The design of intelligent drives for this

  6. The role of renewable distributed generation in California's electricity system

    Microsoft Academic Search

    G. Simons; P. Sethi; R. Davis; K. DeGroat; D. Comwell; B. Jenkins

    2001-01-01

    Rolling blackouts, escalating electricity prices, ratepayers on the verge of open revolt, and electric utilities publicly threatening bankruptcy have brought California's electricity system under intense scrutiny. It is clear that California's electricity system is in imbalance. Causes of the imbalance include slower than expected increases in generating capacity, unexpectedly high demand growth rates and insufficient electricity delivery capability. This paper

  7. Constructing reliable distributed communication systems with CORBA

    Microsoft Academic Search

    Silvano Maffeis; Douglas C. Schmidt

    1997-01-01

    Communication software and distributed services for next-generation applications must be reliable, efficient, flexible, and reusable. These requirements motivate the use of the Common Object Request Broker Architecture (CORBA). However, building highly available applications with CORBA is hard. Neither the CORBA standard nor conventional implementations of CORBA directly address complex problems related to distributed computing, such as real-time or high-speed quality

  8. Open systems dynamics for propagating quantum fields

    NASA Astrophysics Data System (ADS)

    Baragiola, Ben Quinn

    In this dissertation, I explore interactions between matter and propagating light. The electromagnetic field is modeled as a Markovian reservoir of quantum harmonic oscillators successively streaming past a quantum system. Each weak and fleeting interaction entangles the light and the system, and the light continues its course. In the context of quantum tomography or metrology one attempts, using measure- ments of the light, to extract information about the quantum state of the system. An inevitable consequence of these measurements is a disturbance of the system's quantum state. These ideas focus on the system and regard the light as ancillary. It serves its purpose as a probe or as a mechanism to generate interesting dynamics or system states but is eventually traced out, leaving the reduced quantum state of the system as the primary mathematical subject. What, then, when the state of light itself harbors intrinsic self-entanglement? One such set of states, those where a traveling wave packet is prepared with a defi- nite number of photons, is a focal point of this dissertation. These N-photon states are ideal candidates as couriers in quantum information processing device. In con- trast to quasi-classical states, such as coherent or thermal fields, N-photon states possess temporal mode entanglement, and local interactions in time have nonlocal consequences. The reduced state of a system probed by an N-photon state evolves in a non-Markovian way, and to describe its dynamics one is obliged to keep track of the field's evolution. I present a method to do this for an arbitrary quantum system using a set of coupled master equations. Many models set aside spatial degrees of freedom as an unnecessary complicating factor. By doing so the precision of predictions is limited. Consider a ensemble of cold, trapped atomic spins dispersively probed by a paraxial laser beam. Atom-light coupling across the ensemble is spatially inhomogeneous as is the radiation pattern of scattered light. To achieve strong entanglement between the atoms and photons, one must match the spatial mode of the collective radiation from the ensemble to the mode of the laser beam while minimizing the effects of decoherence due to optical pumping. In this dissertation, I present a three-dimensional model for a quantum light-matter interface for propagating quantum fields specifically equipped to address these issues. The reduced collective atomic state is described by a stochastic master equation that includes coherent collective scattering into paraxial modes, decoher- ence by local inhomogeneous diffuse scattering, and measurement backaction due to continuous observation of the light. As the light is measured, backaction transmutes atom-light entanglement into entanglement between the atoms of the ensemble. This formalism is used to study the impact of spatial modes in the squeezing of a collec- tive atomic spin wave via continuous measurement. The largest squeezing occurs precisely in parameter regimes with significant spatial inhomogeneities, far from the limit in which the interface is well approximated by a one-dimensional, homogeneous model.

  9. 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.

  10. Experimental specification of open systems evolution physical principles

    NASA Astrophysics Data System (ADS)

    Brilkov, A. V.; Loginov, I. A.; Morozova, E. V.; Pechurkin, N. S.

    According to M. Eigen classification, open systems are thermodynamic systems able to maintain stable stationary state of two types: with constant flows and with constant organization case (or constant reacting forces). Thus, experimentalists possess open systems of two major types of evolution both for biology and thermodynamics. If evolutionary changes or transfer from one steady state to another in the result of changing qualitative properties of the system (e.g. after the processes of mutation or selection) take place in such systems, the main characteristics of these genetic reorganizations in populations of macromolecules or species, i.e. evolution steps can be measured without losing the community of approach from the point of view of both biology and physics. By now this has not been realized from the point of view of methodology, though a lot of data on the work of both types of "evolutionary machines" has been collected. In our experiments we used the Escherichia coli genetically engineered strains, containing in plasmids the cloned genes of marine photobacteria bioluminescence and genes of green fluorescent protein (GFP), which expression level can be easily changed and controlled. In spite of the apparent kinetic diversity of evolutionary transfers in two types of open systems, the general mechanisms characterizing the increase of used energy flow by bacterial populations can be revealed at their study. According to our observations, at spontaneous transfer from one steady state to another (e.g. in the process of microevolution), heat dissipation characterizing the rate of entropy growth should increase rather then decrease or maintain steady as M. Eigen, G. Nikolis and I. Prigogin believed. The results require further development of thermodynamic theory of open pre- and biological systems evolution.

  11. 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.

  12. Numerical Analysis of a Cold Air Distribution System

    E-print Network

    Zhu, L.; Li, R.; Yuan, D.

    2006-01-01

    Cold air distribution systems may reduce the operating energy consumption of air-conditioned air supply system and improve the outside air volume percentages and indoor air quality. However, indoor temperature patterns and velocity field are easily...

  13. Motion Planning for Metamorphic Systems: Feasibility, Decidability and Distributed

    E-print Network

    Dumitrescu, Adrian

    1 Motion Planning for Metamorphic Systems: Feasibility, Decidability and Distributed address a number of issues related to motion planning and analysis of rectangular metamorphic robotic questions in the analysis of metamorphic systems. In particular the following two questions are shown

  14. Micropolis: A Virtual City for Water Distribution System Research Applications

    E-print Network

    Torres, Jacob

    2006-07-11

    been developed, including a comprehensive water distribution system, as a first entry into such a library. “Micropolis” is a virtual city of 5000 residents fully described in both geographic information systems (GIS) and EPANet hydraulic model...

  15. Toward an Intelligent Distributed Safety Instrumented Systems: Dependability Evaluation

    E-print Network

    Paris-Sud XI, Université de

    are studied for structures which have intelligence in the instruments constituting the Safety InstrumentedToward an Intelligent Distributed Safety Instrumented Systems: Dependability Evaluation Abdelhak Systems (SIS) in order to determine the contribution of the intelligent instruments in the safety

  16. Digital rights management on open and semi-open networks

    Microsoft Academic Search

    Mikko VÄLIMÄKI; Olli PITKÄNEN

    2001-01-01

    Gives an overview of how the openness of the future Internet affects digital rights management (DRM). There will be open and semi-open parts in the future Internet. DRM systems enable many important features of information product distribution on the Internet. At the same time, these systems have significant costs: how should content distributors maintain user friendliness and solve revenue-earning difficulties?

  17. Quantum Metrology in Open Systems: Dissipative Cramér-Rao Bound

    NASA Astrophysics Data System (ADS)

    Alipour, S.; Mehboudi, M.; Rezakhani, A. T.

    2014-03-01

    Estimation of parameters is a pivotal task throughout science and technology. The quantum Cramér-Rao bound provides a fundamental limit of precision allowed to be achieved under quantum theory. For closed quantum systems, it has been shown how the estimation precision depends on the underlying dynamics. Here, we propose a general formulation for metrology scenarios in open quantum systems, aiming to relate the precision more directly to properties of the underlying dynamics. This feature may be employed to enhance an estimation precision, e.g., by quantum control techniques. Specifically, we derive a Cramér-Rao bound for a fairly large class of open system dynamics, which is governed by a (time-dependent) dynamical semigroup map. We illustrate the utility of this scenario through three examples.

  18. Quantum Metrology in Open Systems: Dissipative Cramér-Rao Bound

    E-print Network

    S. Alipour; M. Mehboudi; A. T. Rezakhani

    2014-03-31

    Estimation of parameters is a pivotal task throughout science and technology. Quantum Cram\\'{e}r-Rao bound provides a fundamental limit of precision allowed to achieve under quantum theory. For closed quantum systems, it has been shown how the estimation precision depends on the underlying dynamics. Here, we propose a general formulation for metrology scenarios in open quantum systems, aiming to relate the precision more directly to properties of the underlying dynamics. This feature may be employed to enhance an estimation precision, e.g., by quantum control techniques. Specifically, we derive a Cram\\'{e}r-Rao bound for a fairly large class of open system dynamics, which is governed by a (time-dependent) dynamical semi-group map. We illustrate the utility of this scenario through three examples.

  19. Open quantum systems approach to atomtronics

    SciTech Connect

    Pepino, R. A.; Cooper, J.; Meiser, D.; Anderson, D. Z.; Holland, M. J. [JILA, National Institute of Standards and Technology and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440 (United States)

    2010-07-15

    We derive a quantum master equation to treat quantum systems interacting with multiple reservoirs. The formalism is used to investigate the atomic transport of bosons across a variety of lattice configurations. We demonstrate how the behavior of an electronic diode, a field-effect transistor, and a bipolar junction transistor can be realized with neutral, ultracold atoms trapped in optical lattices. An analysis of the current fluctuations is provided for the case of the atomtronic diode. Finally, we show that it is possible to demonstrate and logic gate behavior in an optical lattice.

  20. Paths and stochastic order in open systems

    E-print Network

    Umberto Lucia

    2011-01-07

    The principle of maximum irreversible is proved to be a consequence of a stochastic order of the paths inside the phase space; indeed, the system evolves on the greatest path in the stochastic order. The result obtained is that, at the stability, the entropy generation is maximum and, this maximum value is consequence of the stochastic order of the paths in the phase space, while, conversely, the stochastic order of the paths in the phase space is a consequence of the maximum of the entropy generation at the stability.

  1. 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.

  2. 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...

  3. Distribution System Load Flow Using Primal Dual Interior Point Method

    Microsoft Academic Search

    Ravindra Singh; Bikash C. Pal; R. A. Jabr; P. D. Lang

    2008-01-01

    This paper presents a load flow solution for radial and weakly meshed distribution system. The problem is formulated as an optimization problem based on minimization of L1 norm of a vector consisting of power mismatch at every node in a distribution system. The optimization problem is solved using interior point (IP) method. The advantage of interior point method is that

  4. Constraints-driven design space exploration for distributed embedded systems

    Microsoft Academic Search

    Krzysztof Kuchcinski

    2001-01-01

    This paper presents a new method for design space exploration for distributed embedded systems. The method is based on constraint logic programming (CLP) and make it possible to model distributed embedded systems and design requirements using finite domain constraints. Design space exploration tools can then use this model to find different solutions satisfying constraints. An advantage of this method is

  5. Distributed Raman amplifiers for long haul transmission systems

    Microsoft Academic Search

    K. Rottwitt; H. Kidorf; M. Nissov; F. Kerfoot

    1998-01-01

    We have demonstrated that the use of distributed Raman amplification offers significant benefits in terms of low noise accumulation and wide bandwidth for future long haul broadband WDM systems. In a system experiment, we successfully transmitted 10 channels at 10 Gbit\\/s over 7200 km. To demonstrate the potential bandwidth, we designed a 92 mm bandwidth distributed Raman amplifier with a

  6. 14 CFR 23.1445 - Oxygen distribution system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Oxygen distribution system. 23.1445 Section...Miscellaneous Equipment § 23.1445 Oxygen distribution system. Link to an amendment... (a) Except for flexible lines from oxygen outlets to the dispensing units,...

  7. Optimal operation of multiquality water distribution systems: unsteady conditions

    Microsoft Academic Search

    Avi Ostfeld; Elad Salomons

    2004-01-01

    This paper describes the methodology and application of a genetic algorithm scheme tailor-made to EPANET, for optimizing the operation of a water distribution system under unsteady water quality conditions. The water distribution system consists of sources of different qualities, treatment facilities, tanks, pipes, control valves, and pumping stations. The objective is to minimize the total cost of pumping and treating

  8. Risk classification and uncertainty propagation for virtual water distribution systems

    Microsoft Academic Search

    Jacob M. Torres; Kelly Brumbelow; Seth D. Guikema

    2009-01-01

    While the secrecy of real water distribution system data is crucial, it poses difficulty for research as results cannot be publicized. This data includes topological layouts of pipe networks, pump operation schedules, and water demands. Therefore, a library of virtual water distribution systems can be an important research tool for comparative development of analytical methods. A virtual city, “Micropolis”, has

  9. A contamination source identification model for water distribution system security

    Microsoft Academic Search

    A. Preis; A. Ostfeld

    2007-01-01

    This article presents and demonstrates a simple, straightforward genetic algorithm (GA) scheme for contamination source identification to enhance the security of water distribution systems. Related previous work on this subject has concentrated on developing analytical water quality inverse models with two major restrictions: the ability to disclose unique solutions and to handle water distribution systems of large size. These two

  10. Quantum key distribution system clocked at 2 GHz

    E-print Network

    Buller, Gerald S.

    Quantum key distribution system clocked at 2 GHz Karen J. Gordon, Veronica Fernandez, Gerald S, Ireland http://www.phy.hw.ac.uk/resrev/photoncounting/index.html Abstract: An improved quantum key-based quantum key distribution test system performance in terms of transmission distance and quantum bit error

  11. Decentralized adaptive control for a water distribution system

    Microsoft Academic Search

    Didier GEORGES; URA CNRS

    1994-01-01

    This paper considers the design of a decentralized adaptive controller for a water distribution system. This system consists of a 40-kilometer long canal connected to three secondary canals and four main reservoirs supplied by a 7 m3 s-1 river (the Bourne river). More than 20 pumping stations are distributed along the canals, bringing water to the agricultural plain of Valence

  12. 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.

  13. Horizontal Class Fragmentation in Distributed Object Based Systems \\Lambda

    E-print Network

    Ezeife, Christie

    Horizontal Class Fragmentation in Distributed Object Based Systems \\Lambda Christie I. Ezeife­generation'' engineering design environment that exploits object­oriented technologies. Fragmentation enhances application of relations exist, but fragmentation techniques for class objects in a distributed object based system have

  14. Holistic schedulability analysis for distributed hard real-time systems

    Microsoft Academic Search

    Ken Tindell; John Clark

    1994-01-01

    This paper extends the current analysis associated with static priority pre-emptive based scheduling to address the wider problem of analysing schedulability of a distributed hard real-time system; in particular it derives analysis for a distributed system where tasks with arbitrary deadlines communicate by message passing and shared data areas. A simple TDMA protocol is assumed, and analysis developed to bound

  15. Cost Modeling and Design Techniques for Integrated Package Distribution Systems

    E-print Network

    Smilowitz, Karen

    Cost Modeling and Design Techniques for Integrated Package Distribution Systems Karen R. Smilowitz and Carlos F. Daganzo December 23, 2005 Abstract Complex package distribution systems are designed using strategies of package delivery firms today. Key words: Network design problem, continuum approximation

  16. The Hidden Object Searching Method for Distributed Autonomous Robotic Systems

    Microsoft Academic Search

    Han-Ul Yoon; Dong-Hoon Lee; Kwee-Bo Sim

    In this paper, we present the strategy of object search for distributed autonomous robotic systems (DARS). The DARS are the systems that consist of multiple autonomous robotic agents to whom required functions are distributed. For instance, the agents should recognize their surrounding at where they are located and generate some rules to act upon by themselves. In this paper, we

  17. Dealing with Overload in Distributed Stream Processing Systems

    Microsoft Academic Search

    Nesime Tatbul

    2006-01-01

    Overload management has been an important problem for large-scale dynamic systems. In this paper, we study this prob- lem in the context of our Borealis distributed stream process- ing system. We show that server nodes must coordinate in their load shedding decisions to achieve global control on out- put quality. We describe a distributed load shedding approach which provides this

  18. Microeconomic Algorithms for Load Balancing in Distributed Computer Systems

    Microsoft Academic Search

    Donald F. Ferguson; Yechiam Yemini; Cliristos Nikolaou

    1988-01-01

    A novel approach to allocating and sharing communication and computational resources in a distributed system is described. The approach, which is based on concepts drawn from microeconomics, uses algorithms that are competitive rather than cooperative. The effectiveness of these concepts is demonstrated by describing an economy that improves the performance of a distributed system by implementing load balancing. In this

  19. BACKWARD ERROR RECOVERY PROTOCOLS IN DISTRIBUTED MOBILE SYSTEMS: A SURVEY

    Microsoft Academic Search

    Sunil KumarGupta; R. K Chauhan; Parveen Kumar

    This survey covers backward error recovery techniques for distributed systems specially the distributed mobile systems. Backward error recovery protocols have been classified into user triggered checkpointing and transparent checkpointing. Transparent checkpointing can be uncoordinated checkpointing, Coordinated checkpointing, Quasi Synchronous or communication-induced checkpointing and Message Logging based Checkpointing. Through out this survey we, highlight the research issues that are at the

  20. Low Overhead Optimal Checkpointing for Mobile Distributed Systems

    Microsoft Academic Search

    Lalit Kumar; Muldip Mishra; Ramesh Chander Joshi

    2003-01-01

    A checkpoint algorithm for a mobile distributed computing system (MDCS) needs to handle many new issues like: mobility, low bandwidth of wireless channels, lack of stable storage on mobile nodes, disconnections, limited battery power and high failure rate of mobile nodes. These issues make traditional checkpointing techniques unsuitable for mobile distributed systems. Coordinated checkpointing may be useful to checkpoint MDCS