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1

An open design approach for distributed energy management systems  

Microsoft Academic Search

Energy management system (EMS) design has traditionally been a top-down process, in which a single vector provides the algorithms, software, and hardware to meet the utility's functional specifications. Trends in power systems, such as the move by utilities to open systems architectures, and the development of distributed computing systems indicate that this process must be changed to incorporate the new

Liam Murphy; Felix F. Wu

1993-01-01

2

Resonance Width Distribution for Open Chaotic Quantum Systems  

NASA Astrophysics Data System (ADS)

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.

Shchedrin, Gavriil

2012-10-01

3

Distributed Norm Enforcement: Ostracism in Open Multi-Agent Systems  

Microsoft Academic Search

Enforcement in normative agent societies is a complex issue, which becomes more problematic as these societies become more decen- tralized and open. A new distributed mechanism is presented to enforce norms by ostracizing agents that do not abide by them in their interac- tions with other agents in the society. Simulations are run to check the mechanism's impact in dierent

Adrian Perreau De Pinninck; Carles Sierra; W. Marco Schorlemmer

2008-01-01

4

Defining Policies for Performance Management in Open Distributed Systems  

Microsoft Academic Search

An important issue for managing distributed systems is achieving a high flexibility of management components. A means to increase flexibility of management systems is defining a policy for the managers behaviour. A policy determines the behaviour of an object and is enforced by a manager (or administrator) object. In this paper, a performance policy for a trader policy domain is

B. Meyer; C. Popien

1994-01-01

5

Towards Model-Driven Validation of Autonomic Software Systems in Open Distributed Environments  

E-print Network

Towards Model-Driven Validation of Autonomic Software Systems in Open Distributed Environments J). These fluctuations must be taken into account when deploying these systems. Autonomic computing aims at realizing that static validation is mandatory for large autonomic distributed systems. We identify two kinds

Boyer, Edmond

6

Integrated Network Security Protocol Layer for Open-Access Power Distribution Systems  

Microsoft Academic Search

Power distribution system cyber-security concerns are increasing rapidly with growing demands for open accesses to the distribution systems for electricity generation and trading imposed by new government deregulations. This paper proposes a new integrated network security protocol layer, located below the data-link layer of DNP3 - a popular utility protocol, to enhance the data transmission cyber-security for power distribution systems.

Todd Mander; Farhad Nabhani; Lin Wang; Richard Cheung

2007-01-01

7

Development of an Open Source GIS based Distributed Hydrological model System - MWEasyDHM  

NASA Astrophysics Data System (ADS)

Spatially distributed hydrological model is an important tool for studying the hydrological cycle, making flood forecasting, simulating environmental and ecological processes and estimating crop water demand and so on. Successful distributed hydrological model and systems have been further achieved in many developed countries. However, there needs one GIS based Distributed Hydrological Model system to carry out hydrological simulation suitable for current conditions of China. In this paper a distributed hydrological model system for easy manipulation, MWEasyDHM (MapWindow based Distributed Hydrological Model), was developed based on MapWindow GIS platform, an open source GIS software. The system contains pretreatment, model parameters optimization and posttreatment modules to simplify the works of building distributed hydrological model. The pretreatment module includes hydrological analysis, model parameters estimation and weather data interpolation parts based on huge amount of spatial and temporal data sets such as weather, land use, soil type, etc. With the pretreatment results, distributed hydrological model could be calculated and optimal model parameters could be obtained with LH-OAT parameters sensitivity analysis and SCE-UA parameters optimization. After model simulation, the model results could be displayed with tables, charts and GIS forms, in addition, spatial and temporal statistics and analysis could be easily achieved with the postreatment. Finally, a brief application of MWEasyDHM will be described to demonstrate the flexibilities and capacities of the model system. With the successful development of MWEasyDHM, the processes of model building, calibration and application could be much easier and distributed hydrological model could be easily applied to the areas of water resources management.

Lei, Xiaohui; Wang, Yuhui; Jiang, Yunzhong; Wang, Hao; Tian, Yu; Liao, Weihong

2010-05-01

8

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

SciTech Connect

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).

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

9

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

NASA Astrophysics Data System (ADS)

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

Davies, Nigel; Raymond, Kerry; Blair, Gordon

1999-03-01

10

Advanced Design Concepts for Open Distributed Systems Development Lus Ferreira Piresb  

E-print Network

Sinderenb , Chris A. Vissersa, b (a) Telematics Research Centre, PO Box 217, 7500 AE Enschede in the framework of the European research programs ESPRIT, RACE and Telematics, aiming at developing large scale open distributed telematics and telecommunications sys- tems. Experience with the development

Pires, Luís Ferreira

11

Distributed Information Systems  

Microsoft Academic Search

The Information Systems of the future will be distributed, heterogeneous and open. They will require the integration of five key technologies — databases, multimedia, object orientation, artificial intelligence and telecommunications. This paper explains the contribution of these technologies to the vision of the future and how they can be integrated. Key technical challenges and open research issues will be discussed.

Jane Grimson

1995-01-01

12

OpenGIS Conforming Map-Feature Server Implementation Specifications in Component-based Distributed Systems  

Microsoft Academic Search

Geo-data and geo-service interoperations are important to Geographic Information System (GIS) users. To meet such needs, standard specifications are required for geo-data and geo-services. The OpenGIS Consortium (OGC) defined abstract specifications and partial implementation specifications, which can make diverse geo-data and geo-services accessible to conforming applications. However the implementation specifications are not complete, particularly in the areas of interactive map

Shifeng Zhang; Steve Goddard

13

ccsd00001148 Experimental open air quantum key distribution with a  

E-print Network

implementation of a quantum key distribution (QKD) system with a single photon source, operating at night in openccsd­00001148 (version 1) : 16 Feb 2004 Experimental open air quantum key distribution #12; Experimental open air quantum key distribution with a single photon source 2 1. Introduction Key

14

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

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

15

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

E-print Network

HRLT IPCSS 101 LIST OF FIGURES Figure 1. OSI Reference Model Page 21 2. A hypermedia system taxonomy 3. Generic information system process 23 30 4. Information system, 5. Current architectural design terminology 31 36 6. Message structure... protocols through the defined transmission media. A transmission medium allows messages to be passed from one process to another. Examples of IPC transmission media in use include shared memory, files, and UNIX sockets. Furthermore, transmission media may...

Nuernberg, Peter John

2012-06-07

16

A Framework for Open, Flexible and Distributed Learning.  

ERIC Educational Resources Information Center

Designing open, flexible distance learning systems on the World Wide Web requires thoughtful analysis and investigation combined with an understanding of both the Web's attributes and resources and the ways instructional design principles can be applied to tap the Web's potential. A framework for open, flexible, and distributed learning has been…

Khan, Badrul H.

17

75 FR 14076 - Express Mail Open and Distribute and Priority Mail Open and Distribute Changes and Updates  

Federal Register 2010, 2011, 2012, 2013

...Open and Distribute and Priority Mail Open and Distribute...goal to provide a secure method for Open and Distribute...Open and Distribute and Priority Mail Open and Distribute...16.1.5 Payment Method [Revise the third sentence...as follows:] * * * Priority Mail postage must...

2010-03-24

18

Income distribution, factor endowments, and trade openness  

Microsoft Academic Search

This paper studies the empirical links among factor endowments, trade and personal income distribution. By using panel data, we show that land and capital intensive countries have a less equal income distribution while skill intensive countries have a more equal income distribution. We also show that the effects of trade openness on inequality depend on factor endowments in a way

Antonio Spilimbergo; Juan Luis Londoño; Miguel Székely

1999-01-01

19

FRIB cryogenic distribution system  

SciTech Connect

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.

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

2014-01-01

20

Biodiversity and the Lotka-Volterra theory of species interactions: open systems and the distribution of logarithmic densities.  

PubMed Central

Theoretical interest in the distributions of species abundances observed in ecological communities has focused recently on the results of models that assume all species are identical in their interactions with one another, and rely upon immigration and speciation to promote coexistence. Here we examine a one-trophic level system with generalized species interactions, including species-specific intraspecific and interspecific interaction strengths, and density-independent immigration from a regional species pool. Comparisons between results from numerical integrations and an approximate analytic calculation for random communities demonstrate good agreement, and both approaches yield abundance distributions of nearly arbitrary shape, including bimodality for intermediate immigration rates. PMID:15347523

Wilson, William G.; Lundberg, Per

2004-01-01

21

Distribution system state estimation  

NASA Astrophysics Data System (ADS)

With the development of automation in distribution systems, distribution SCADA and many other automated meters have been installed on distribution systems. Also Distribution Management System (DMS) have been further developed and more sophisticated. It is possible and useful to apply state estimation techniques to distribution systems. However, distribution systems have many features that are different from the transmission systems. Thus, the state estimation technology used in the transmission systems can not be directly used in the distribution systems. This project's goal was to develop a state estimation algorithm suitable for distribution systems. Because of the limited number of real-time measurements in the distribution systems, the state estimator can not acquire enough real-time measurements for convergence, so pseudo-measurements are necessary for a distribution system state estimator. A load estimation procedure is proposed which can provide estimates of real-time customer load profiles, which can be treated as the pseudo-measurements for state estimator. The algorithm utilizes a newly installed AMR system to calculate more accurate load estimations. A branch-current-based three-phase state estimation algorithm is developed and tested. This method chooses the magnitude and phase angle of the branch current as the state variable, and thus makes the formulation of the Jacobian matrix less complicated. The algorithm decouples the three phases, which is computationally efficient. Additionally, the algorithm is less sensitive to the line parameters than the node-voltage-based algorithms. The algorithm has been tested on three IEEE radial test feeders, both the accuracy and the convergence speed. Due to economical constraints, the number of real-time measurements that can be installed on the distribution systems is limited. So it is important to decide what kinds of measurement devices to install and where to install them. Some rules of meter placement based on this state estimation algorithm are proposed and tested. These rules can improve the accuracy of the estimation results.

Wang, Haibin

22

Open quantum system identification  

E-print Network

Engineering quantum systems offers great opportunities both technologically and scientifically for communication, computation, and simulation. The construction and operation of large scale quantum information devices presents a grand challenge and a major issue is the effective control of coherent dynamics. This is often in the presence of decoherence which further complicates the task of determining the behaviour of the system. Here, we show how to determine open system Markovian dynamics of a quantum system with restricted initialisation and partial output state information.

Sophie G. Schirmer; Daniel K. L. Oi; Weiwei Zhou; Erling Gong; Ming Zhang

2012-05-28

23

Distributed resources and distribution system infrastructure  

Microsoft Academic Search

Distributed resources (DR) are in transition from the lab to the marketplace. The defining characteristic of DR is that they are active devices installed at the distribution system level, as opposed to the transmission level. While no specific size range has been defined, most distribution systems would have difficulty accommodating distributed generating resources larger than 10 MW\\/MVA at any single

A. F. Zobaa

2006-01-01

24

Hadoop distributed file system for the Grid  

Microsoft Academic Search

Data distribution, storage and access are essential to CPU-intensive and data-intensive high performance Grid computing. A newly emerged file system, Hadoop distributed file system (HDFS), is deployed and tested within the Open Science Grid (OSG) middleware stack. Efforts have been taken to integrate HDFS with other Grid tools to build a complete service framework for the Storage Element (SE). Scalability

G. Attebury; A. Baranovski; K. Bloom; B. Bockelman; D. Kcira; J. Letts; T. Levshina; C. Lundestedt; T. Martin; W. Maier; Haifeng Pi; A. Rana; I. Sfiligoi; A. Sim; M. Thomas; F. Wuerthwein

2009-01-01

25

ccsd-00001148(version1):16Feb2004 Experimental open air quantum key distribution with a  

E-print Network

of a quantum key distribution (QKD) system with a single photon source, operating at night in open airccsd-00001148(version1):16Feb2004 Experimental open air quantum key distribution with a single air quantum key distribution with a single photon source 2 1. Introduction Key distribution remains

Paris-Sud XI, Université de

26

Open quantum systems  

Microsoft Academic Search

The damping of the harmonic oscillator is studied in the framework of the\\u000aLindblad theory for open quantum systems. A generalization of the fundamental\\u000aconstraints on quantum mechanical diffusion coefficients which appear in the\\u000amaster equation for the damped quantum oscillator is presented; the\\u000aSchr\\\\\\

A. Isar; A. Sandulescu; H. Scutaru; E. Stefanescu; W. Scheid

2004-01-01

27

Quantum Mechanics + Open Systems  

E-print Network

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

Steinhoff, Heinz-Jürgen

28

Distribution system simulator  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

29

Distributed Virtual System (DIVIRS) Project  

NASA Technical Reports Server (NTRS)

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.

Schorr, Herbert; Neuman, B. Clifford

1993-01-01

30

DIstributed VIRtual System (DIVIRS) project  

NASA Technical Reports Server (NTRS)

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.

Schorr, Herbert; Neuman, B. Clifford

1994-01-01

31

Distributed Virtual System (DIVIRS) project  

NASA Technical Reports Server (NTRS)

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.

Schorr, Herbert; Neuman, B. Clifford

1993-01-01

32

Chittagong distribution system completed  

SciTech Connect

Having completed the 108 mile Bakhrabad to Chittagong gas pipeline, the contractor for the project recently completed the second phase of the project, the Chittagong ring main distribution system. The pipeline is vital to the Bangladesh economy, and the ring main will allow savings in the region of $100 million annually in energy costs. The construction of the system is described.

Not Available

1984-08-01

33

Opening and Closing in Open Systems.  

ERIC Educational Resources Information Center

In open information systems, such as in the case of human interchange with the self and the environment, input quantities have no upper limits. The human information utilization system, however, is psychologically and behaviorally unable to accept ever increasing loads of information. Because of this apparent fact, human information systems should…

Klapp, Orrin E.

34

Open Source Live Distributions for Computer Forensics  

NASA Astrophysics Data System (ADS)

Current distributions of open source forensic software provide digital investigators with a large set of heterogeneous tools. Their use is not always focused on the target and requires high technical expertise. We present a new GNU/Linux live distribution, named CAINE (Computer Aided INvestigative Environment) that contains a collection of tools wrapped up into a user friendly environment. The CAINE forensic framework introduces novel important features, aimed at filling the interoperability gap across different forensic tools. Moreover, it provides a homogeneous graphical interface that drives digital investigators during the acquisition and analysis of electronic evidence, and it offers a semi-automatic mechanism for the creation of the final report.

Giustini, Giancarlo; Andreolini, Mauro; Colajanni, Michele

35

Naval open systems architecture  

NASA Astrophysics Data System (ADS)

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.

Guertin, Nick; Womble, Brian; Haskell, Virginia

2013-05-01

36

Characteristics of Open Learning Systems.  

ERIC Educational Resources Information Center

The ideal concept of open education would take the form of education permanente, although no present program includes all the features implied by this concept. Up to now the literature on open learning has focused on concern for a learner oriented system. The present focus is on the open learning system itself, with the identification of 10…

Wedemeyer, Charles A.

37

Seamless Data Distribution System  

NSDL National Science Digital Library

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.

Usgs

38

Distributed Deliberative Recommender Systems  

NASA Astrophysics Data System (ADS)

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

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

39

Pade spectrum decompositions of quantum distribution functions and optimal hierarchical equations of motion construction for quantum open systems  

SciTech Connect

Pade spectrum decomposition is an optimal sum-over-poles expansion scheme of Fermi function and Bose function [J. Hu, R. X. Xu, and Y. J. Yan, J. Chem. Phys. 133, 101106 (2010)]. In this work, we report two additional members to this family, from which the best among all sum-over-poles methods could be chosen for different cases of application. Methods are developed for determining these three Pade spectrum decomposition expansions at machine precision via simple algorithms. We exemplify the applications of present development with optimal construction of hierarchical equations-of-motion formulations for nonperturbative quantum dissipation and quantum transport dynamics. Numerical demonstrations are given for two systems. One is the transient transport current to an interacting quantum-dots system, together with the involved high-order co-tunneling dynamics. Another is the non-Markovian dynamics of a spin-boson system.

Hu Jie; Luo Meng; Jiang Feng [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong); Xu Ruixue [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yan Yijing [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong); Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2011-06-28

40

Distributed System Design Checklist  

NASA Technical Reports Server (NTRS)

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.

Hall, Brendan; Driscoll, Kevin

2014-01-01

41

Control of open quantum systems  

E-print Network

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 ...

Boulant, Nicolas

2005-01-01

42

Quality monitored distributed voting system  

DOEpatents

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.

Skogmo, D.

1997-03-18

43

Quality monitored distributed voting system  

SciTech Connect

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.

Skogmo, David (Albuquerque, NM)

1997-01-01

44

AGENT-BASED MANAGEMENT AND OPTIMIZATION SYSTEM FOR DISTRIBUTED COMPUTING  

Microsoft Academic Search

Distributed computing systems aim to connect human and information resources in a transparent, open and scalable way. Users dispersed over a computer network have to virtually collaborate using distributed tools. Multi-agent systems and ant colony optimization are investigated with the aim of compiling a successful approach to solve distributed computing problems. Composed of several interacting agents, multi-agent systems have the

Camelia Chira; D. Dumitrescu

45

Dynamical identification of open quantum systems  

E-print Network

I propose a quantum trajectories approach to parametric identification of the effective Hamiltonian for a Markovian open quantum system, and discuss an application motivated by recent experiments in cavity quantum electrodynamics. This example illustrates a strategy for quantum parameter estimation that efficiently utilizes the information carried by correlations between measurements distributed in time.

Hideo Mabuchi

1996-08-13

46

Onsite Wastewater Treatment Systems: Spray Distribution System  

E-print Network

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...

Lesikar, Bruce J.

2008-10-23

47

Cooperation in Open Distributed Systems  

E-print Network

Skype) P2P: Olympic games 2008 live-broadcast over peer-to-peer networks ,,Social" networks: Facebook is inserted here, it can block (or spy on) keyword requests for ,,Simpsons", ,,Simpsons Movie", etc. #12

Schmid, Stefan

48

User Registration Systems for Distributed Systems  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

49

Process evaluation distributed system  

NASA Technical Reports Server (NTRS)

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.

Moffatt, Christopher L. (Inventor)

2006-01-01

50

Open source portal to distributed image repositories  

NASA Astrophysics Data System (ADS)

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.

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

2004-04-01

51

Toward a New Computing Model for an Open Distributed Environment  

Microsoft Academic Search

This paper proposes a new computing model called computational field model, or CFMfor short, for solving a problem in an object-oriented open distributed environment. In thismodel, we envisage an open-ended distributed environment as a continuous computationalfield. We introduce the notions of distance between objects and the mass of an objectto the model. Thus, solving a problem can be seen as

Mario Tokoro

1989-01-01

52

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...

53

Simulation of open quantum systems  

E-print Network

We present an approach for the semiclassical treatment of open quantum systems. An expansion into localized states allows restriction of a simulation to a fraction of the environment that is located within a predefined vicinity of the system. Adding and dropping environmental particles during the simulation yields an effective reduction of the size of the system that is being treated.

Florian Mintert; Eric J. Heller

2008-03-27

54

Constructing Distributed Systems in Conic  

Microsoft Academic Search

Existing distributed systems vary from those which merely provide interconnection of autonomous systems to those which provide a complete language environment for writing distributed programs. The former tend to support flexibility and provide ready access to system facilities, but suffer by being complex to use. Language environments are simpler to use and can provide safer environments by performing checks, but

Jeff Magee; Jeff Kramer; Morris Sloman

1989-01-01

55

Control of Distributed Power Systems  

Microsoft Academic Search

A large number of distributed generation (DG) units are being integrated into power systems at distribution level. The DG units play an essential role in affecting the efficiency and performance of power systems. This paper describes some possible controlling modes of DG units. The operation and control of the power systems consisting of DG units, in particular separated subsystems, are

Z. Chen; Y Hu; F. Blaabjerg

2006-01-01

56

Wireless distributed functional electrical stimulation system  

PubMed Central

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

2012-01-01

57

Distributed systems status and control  

NASA Technical Reports Server (NTRS)

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.

Kreidler, David; Vickers, David

1990-01-01

58

A prototype Distributed Audit System  

SciTech Connect

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.

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

1993-08-01

59

The LOCUS Distributed Operating System  

Microsoft Academic Search

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

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

1983-01-01

60

PARALLEL AND DISTRIBUTED SIMULATION SYSTEMS  

Microsoft Academic Search

Originating from basic research conducted in the 1970's and 1980's, the parallel and distributed simulation field has ma- tured over the last few decades. Today, operational systems have been fielded for applications such as military training, analysis of communication networks, and air traffic control systems, to mention a few. This tutorial gives an overview of technologies to distribute the execution

Richard M. Fujimoto

1999-01-01

61

Exploiting replication in distributed systems  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

62

OpenSees: Open System for Earthquake Engineering Simulation  

NSDL National Science Digital Library

The Open System for Earthquake Engineering Simulation (OpenSees) is a project of the Pacific Earthquake Engineering Research Center. OpenSees is an open source "software framework for developing applications to simulate the performance of structural and geotechnical systems subjected to earthquakes." The project's homepage maintains resources for users and developers, including downloadable source code, extensive documentation, and instructions on how to contribute code. Several links to other research projects that are using the OpenSees tool are provided. Additionally, an OpenSees user's workshop was held in August 2003, and the presentations from the event are available.

63

Open vs. closed Apple music distribution platform  

E-print Network

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 ...

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

2008-01-01

64

DPS Quantum Key Distribution System  

Microsoft Academic Search

Differential-phase-shift (DPS) quantum key distribution (QKD) is one scheme of quantum key distribution whose security is based on the quantum nature of lightwave. This protocol features simplicity, a high key creation rate, and robustness against photon-number-splitting attacks. We describe DPS-QKD in this paper, including its setup and operation, eavesdropping against DPS-QKD, system performance, and modified systems to improve the system

Kyo Inoue

2010-01-01

65

Foundations of Distributed Systems  

E-print Network

days, P2P users mostly shared music, pictures, and software; nowadays books, movies or tv shows have as the "theory behind file sharing protocols". In other words, how do Internet hosts need to be organized applications beyond file sharing, e.g., the Internet domain name system (DNS). · A broader view generalizes P2P

Schmid, Stefan

66

DISTRIBUTION SYSTEM ISSUES  

EPA Science Inventory

The recently promulgated Arsenic Rule will require that many new drinking water systems treat their water to remove arsenic. Iron based treatment technologies including iron removal and iron coagulation are effective at reducing arsenic in water because iron surfaces have a stron...

67

The Hadoop Distributed File System  

Microsoft Academic Search

The Hadoop Distributed File System (HDFS) is designed to store very large data sets reliably, and to stream those data sets at high bandwidth to user applications. In a large cluster, thousands of servers both host directly attached storage and execute user application tasks. By distributing storage and computation across many servers, the resource can grow with demand while remaining

Konstantin Shvachko; Hairong Kuang; Sanjay Radia; Robert Chansler

2010-01-01

68

An Open Source Simulation System  

NASA Technical Reports Server (NTRS)

An investigation into the current state of the art of open source real time programming practices. This document includes what technologies are available, how easy is it to obtain, configure, and use them, and some performance measures done on the different systems. A matrix of vendors and their products is included as part of this investigation, but this is not an exhaustive list, and represents only a snapshot of time in a field that is changing rapidly. Specifically, there are three approaches investigated: 1. Completely open source on generic hardware, downloaded from the net. 2. Open source packaged by a vender and provided as free evaluation copy. 3. Proprietary hardware with pre-loaded proprietary source available software provided by the vender as for our evaluation.

Slack, Thomas

2005-01-01

69

Implementation of WFQ in a Distributed Open Software Router  

E-print Network

the advantages of an open platform [4]­[6], [9]­[11]. Most recent research has focused only on the performance a single logical router has been proposed by some researchers [5], [9], [11]. A distributed architecture PC OSRs can be overcome in a distributed configuration. In fact, large routers using commodity PCs

Sahoo, Anirudha

70

The Raid distributed database system  

NASA Technical Reports Server (NTRS)

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.

Bhargava, Bharat; Riedl, John

1989-01-01

71

14 CFR 29.1355 - Distribution system.  

Code of Federal Regulations, 2010 CFR

...ROTORCRAFT Equipment Electrical Systems and Equipment § 29... (a) The distribution system includes the distribution...independent sources of electrical power for particular equipment or systems are required by...

2010-01-01

72

14 CFR 25.1355 - Distribution system.  

Code of Federal Regulations, 2010 CFR

...AIRPLANES Equipment Electrical Systems and Equipment § 25... (a) The distribution system includes the distribution...independent sources of electrical power for particular equipment or systems are required by...

2010-01-01

73

How robust are distributed systems  

NASA Technical Reports Server (NTRS)

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

Birman, Kenneth P.

1989-01-01

74

A New Heuristic Reconfiguration Algorithm for Large Distribution Systems  

Microsoft Academic Search

This paper presents a reconfiguration algorithm that is specially suited to large-scale distribution systems. The algorithm uses a heuristic strategy that starts with the system in a meshed status, with all maneuverable switches closed. The choice of the switches to be opened is based on the calculation of the minimum total system losses, using a load-flow program. A refinement on

Flávio Vanderson Gomes; Sandoval Carneiro; M. P. Vinagre; P. A. N. Garcia; L. R. Araujo

2005-01-01

75

Wide-open and scanning ESM systems  

Microsoft Academic Search

A comparison is conducted between open and scanning Electronic Warfare Support Measures (ESM) systems. Wide open ESM systems are generally known as high probability of intercept systems, while scanning systems have a higher sensitivity. The interception capability of the RF part of both types of systems is discussed. Two fundamentally different antenna types are currently employed in ESM systems, including

E. van Nieuwenhuizen

1981-01-01

76

Regulated Coordination in Open Distributed Naftaly H. Minsky and Victoria Ungureanu  

E-print Network

Regulated Coordination in Open Distributed Systems Naftaly H. Minsky and Victoria Ungureanu have to coordinate its activities with members of several such subsystems, under different coordination policies. To support coordination in such hybrid systems, we introduce in this paper a new concept

Minsky, Naftaly

77

Quantum Entanglement in Open Systems  

SciTech Connect

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, the master equation for two independent harmonic oscillators interacting with an environment is solved in the asymptotic long-time regime. Using the Peres-Simon necessary and sufficient condition for separability of two-mode Gaussian states, we show that the two non-interacting systems become asymptotically entangled for certain environments, so that in the long-time regime they manifest non-local quantum correlations. We calculate also the logarithmic negativity characterizing the degree of entanglement of the asymptotic state.

Isar, Aurelian [Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

2008-01-24

78

Open solutions to distributed control in ground tracking stations  

NASA Technical Reports Server (NTRS)

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.

Heuser, William Randy

1994-01-01

79

Enhanced distributed energy resource system  

DOEpatents

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.

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

2007-07-03

80

The flag taxonomy of open hypermedia systems  

Microsoft Academic Search

This paper presents a taxonomy for open hypermedia systems. The purpose of the Flagl taxonomy is manifold: (1) to provide a framework to classify and concisely describe individual systems, (2) to characterize what an open hypermedia system is, (3) to provide a framework for comparing different systems in a system independent way, and (4) to provide an overview of the

Kasper Østerbye; Uffe Kock Wiil

1996-01-01

81

Mathematical Appendix to Open Economy Models of Distribution and Growth  

E-print Network

Mathematical Appendix to Open Economy Models of Distribution and Growth Robert A. Blecker May 2010) The effect of an increase in the market power parameter (inversely related to market power) on the steady-state wage share is definitely positive: d d = (µ + ) |J| > 0 (A.6) The effect of an increase in the market

Carlini, David

82

RESEARCH Open Access Intratumoral distribution of EGFR mutations and  

E-print Network

RESEARCH Open Access Intratumoral distribution of EGFR mutations and copy number in metastatic lung Background: Activating epidermal growth factor receptor (EGFR) mutations characterize a subgroup of non-small-cell lung cancer that benefit from first line EGFR tyrosine kinase inhibitors (EGFR-TKI). However

Paris-Sud XI, Université de

83

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

E-print Network

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

Carlini, David

84

Distributed vs. Centralized Power Systems Frequency Control  

E-print Network

Distributed vs. Centralized Power Systems Frequency Control Martin Andreasson12 , Dimos V control of electrical power systems. We propose a distributed controller which retains the reference class of large- scale systems are electrical power systems, which employ automatic generation control

Dimarogonas, Dimos

85

An integrated distributed generation optimization model for distribution system planning  

Microsoft Academic Search

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

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

2005-01-01

86

The data distribution satellite system  

NASA Technical Reports Server (NTRS)

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.

Bruno, Ronald C.; Weinberg, Aaron

1991-01-01

87

A reliability assessment methodology for distribution systems with distributed generation  

E-print Network

Reliability assessment is of primary importance in designing and planning distribution systems that operate in an economic manner with minimal interruption of customer loads. With the advances in renewable energy sources, Distributed Generation (DG...

Duttagupta, Suchismita Sujaya

2006-08-16

88

Heat pump thermal distribution systems  

SciTech Connect

A large volume of information on conceptual heat pump systems, component costs and expected operating costs were generated for a wide variety of heat pump systems during this study. Detailed results of this work, too lengthy to be reported in a single volume, have been included in these appendices, which are designated as Volume II of this study. Schematics of possible heat pump and thermal distribution system interactions are included in Appendix B, Matrix of Possible Systems. Appendix C includes the expected cost breakdowns for the systems studied. Operating costs were generated for both the zoned and non-zoned systems. DOE-2 was used to model the 1500 ft{sup 2} ranch house which served as the non-zoned building and the 2300 ft{sup 2} colonial that was divided into two zones. The DOE-2 input decks are given in Appendix D. The heating and cooling load information from the DOE-2 model was used as an input to the simulations for air and hydronic systems. The hour-by-hour simulation output information includes the power requirements for the heat pump, blowers, pumps and auxiliary heating. Appendix E lists two of the simulation programs used. Simulation results for the most practical systems are included in tabular form in Appendix F.

Sarkisian, P.; Cohen, B.; Popelka, A.

1990-08-01

89

Distributed snapshots: determining global states of distributed systems  

Microsoft Academic Search

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

Leslie Lamport

1985-01-01

90

Video distribution system cost model  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

91

Duplex Direct Data Distribution System  

NASA Technical Reports Server (NTRS)

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.

Greenfield, Israel (Technical Monitor)

2001-01-01

92

Distribution System Voltage Regulation by Distributed Energy Resources  

SciTech Connect

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.

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

2014-01-01

93

78 FR 11988 - Open Video Systems  

Federal Register 2010, 2011, 2012, 2013

...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)...

2013-02-21

94

Hypothesis testing with open quantum systems  

E-print Network

Using a quantum circuit model we derive the maximal ability to distinguish which of several candidate Hamiltonians describe an open quantum system. This theory, in particular, provides the maximum information retrievable from continuous quantum measurement records, available when a smaller open quantum system is perturbatively coupled to a broadband quantized environment.

Klaus Molmer

2014-08-20

95

Project Athena as a Distributed Computer System  

Microsoft Academic Search

Project Athena, established in 1983 to improve the quality of education at MIT (Massachussetts Institute of Technology) by providing campuswide, high-quality computing based on a large network of workstations, is discussed, focusing on the design of Athena's distributed workstation system. The requirements of the system are outlined distributed system models are reviewed, other distributed operating systems are described, and issues

George A. Champine; Daniel E. Geer Jr.; William Ruh

1990-01-01

96

R-OSGi-based architecture of distributed smart home system  

Microsoft Academic Search

The conventional architecture of smart home is usually server-centric and this may cause many problems. The distributed architecture presented in this paper is based on multiple OSGi (Open Service Gateway Initiative) platforms. Relative home appliance services which are compliant with R-OSGi middleware for the home network system are also developed. The important aspect of R-OSGi is that it offers distribution

Jiankun Wu; Linpeng Huang; Dejun Wang; Fei Shen

2008-01-01

97

Literature Review on Underfloor Air Distribution (UFAD) Systems  

E-print Network

archives (1980-1997), Elsevier Literature Search Engine, the Center for the Built Environment (CBE), the Building Diagnostics Research Institute. An UFAD system is an HVAC system that uses the open space (i.e., the underfloor plenum) between... transactions and journal papers are main sources about the UFAD systems. (More than 100 papers found) Elsevier Literature Search Engine: Keyword: Displacement Ventilation (26 papers found) Keyword: UnderFloor Air Distribution (2 papers found) Center...

Im, P.; Cho, S.; Haberl, J. S.

2006-01-10

98

Automated Fault Location In Smart Distribution Systems  

E-print Network

of utilizing a suitable fault location method. As distribution systems are gradually evolving into smart distribution systems, application of more accurate fault location methods based on gathered data from various Intelligent Electronic Devices (IEDs...

Lotfifard, Saeed

2012-10-19

99

Open System Architecture design for planet surface systems  

NASA Technical Reports Server (NTRS)

The Open System Architecture is an approach to meeting the needs for flexibility and evolution of the U.S. Space Exploration Initiative program of the manned exploration of the solar system and its permanent settlement. This paper investigates the issues that future activities of the planet exploration program must confront, defines the basic concepts that provide the basis for establishing an Open System Architecture, identifies the appropriate features of such an architecture, and discusses examples of Open System Architectures.

Petri, D. A.; Pieniazek, L. A.; Toups, L. D.

1992-01-01

100

18-mhz clock distribution system  

SciTech Connect

This paper discusses how designing the high-frequency distribution system to allow HP's new 32-bit VLSI processor to operate at 18 mhz proved to be a significant design challenge. The chips required 6 v, two-phase, nonoverlapping clocks with rise times less than 6 ns and overshoot/undershoot less than 1 v. It was decided early in the project that, because of area constraints, the processor chips would not buffer their clocks. However the RAM chips do provide some buffering. Hence the capacitive loading components vary from approximately 300 pf per phase for a CPU chip to approximately 30 pf per phase for a ram chip. In addition, the capacitive loading presented is highly variable because of the dynamic circuits used and depends on which circuits are active. Worst-case tolerances produce capacitive specifications that can vary +or- 30percent and cause unbalanced loads on each phase.

Lob, C.G.; Elkins, A.O.

1983-08-01

101

STABILIZED FIBER OPTIC FREQUENCY DISTRIBUTION SYSTEM  

Microsoft Academic Search

A technique for stabilizing reference frequencies transmitted over flber optic cable in a frequency distribution system is discussed. The distribution system utilizes fiber optic cable as the transmission medium to dietribute precise reference signals from a frequency standard to remote users. The stability goal of the distribution system is to transmit a 100 MH5 signal over a 22 km fiber

Lori E. Primas; George F. Lutes; Richard L. Sydnor

102

Challenges of Using CSCL in Open Distributed Learning.  

ERIC Educational Resources Information Center

As a compulsory part of the study in Pedagogical Information Science at the University of Bergen and Stord/Haugesund College (Norway) during the spring term of 1999, students participated in a distributed group activity that provided experience on distributed collaboration and use of online groupware systems. The group collaboration process was…

Nilsen, Anders Grov; Instefjord, Elen J.

103

A distributed program composition system  

NASA Technical Reports Server (NTRS)

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.

Brown, Robert L.

1989-01-01

104

Stabilized fiber-optic frequency distribution system  

Microsoft Academic Search

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

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

1989-01-01

105

Scaling of Beowulf-class distributed systems  

Microsoft Academic Search

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

John K. Salmon; Christopher Stein; Thomas Sterling

1998-01-01

106

Embedding measurement in Distribution Automation Systems  

Microsoft Academic Search

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

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

2010-01-01

107

Wide-open and scanning ESM systems  

NASA Astrophysics Data System (ADS)

A comparison is conducted between open and scanning Electronic Warfare Support Measures (ESM) systems. Wide open ESM systems are generally known as high probability of intercept systems, while scanning systems have a higher sensitivity. The interception capability of the RF part of both types of systems is discussed. Two fundamentally different antenna types are currently employed in ESM systems, including the rotating beam type and the omnidirectional antenna. Antennas belonging to the rotating beam type can be divided into conventional rotating antennas and phased array antennas. The rotational antenna has a certain frequency-dependent gain due to its directivity. The omnidirectional antenna is mostly of the multibeam type. A number of separate antennas is employed to cover 360 deg in azimuth. Attention is given to narrow-band and broadband receivers, interception by the scanning system, and interception by the wide-open system.

van Nieuwenhuizen, E.

108

Open Source, Open Standards, and Health Care Information Systems  

PubMed Central

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

2011-01-01

109

Computer security in DOE distributed computing systems  

SciTech Connect

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

Hunteman, W.J.

1990-01-01

110

Open Source Course Management and Assessment System  

E-print Network

LON-CAPA: Open Source Course Management and Assessment System Gerd Kortemeyer Michigan State Assembly Course Management Resource Assembly Course Management #12;Campus A Campus B Resource Assembly Course Management Resource Assembly Course Management LON-CAPA Architecture Shared Cross

111

Low jitter RF distribution system  

DOEpatents

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.

Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

2012-09-18

112

Open systems ADA technology demonstration program  

Microsoft Academic Search

On 20 March, 1997 McDonnell Douglas Aerospace (now Boeing), and NAWC-China Lake conducted a demonstration flight as part of the Open Systems Ada Technology (OSAT) program, co-sponsored by the Ada Joint Program Office, the Open Systems Joint Task Force, and the Joint Strike Fighter Program Office. The flight, of a specially modified AV-8B Harrier, accomplished several key objectives: first known

D. C. Winter; B. D. Rest

1997-01-01

113

Open systems Ada technology demonstration program  

Microsoft Academic Search

On 20 March 1997 McDonnell Douglas Aerospace (now Boeing), and NAWC-China Lake conducted a demonstration flight as part of the Open Systems Ada Technology (OSAT) program, co-sponsored by the Ada Joint Program Office, the Open Systems Joint Task Force, and the Joint Strike Fighter Program Office. The flight, of a specially modified AV-8B Harrier, accomplished several key objectives: (1) first

Don C Winter

1999-01-01

114

Open Distributed Architectures for E-Market Design Rudolf K. Keller  

E-print Network

1 Open Distributed Architectures for E-Market Design 1 Rudolf K. Keller Département d on unrelated servers are combined by a market participant), synchronized open auctions, and combinatorial are conducting research in the fields of market design and open distributed architectures. The objective

Keller, Rudolf K.

115

Is data distribution necessary in OpenMP?  

Microsoft Academic Search

This paper investigates the performance implications of data placement in OpenMP programs running on modern ccNUMA multiprocessors. Data locality and minimization of the rate of remote memory accesses are critical for sustaining high performance on these systems. We show that due to the low remote-to-local memory access latency ratio of state-of-the-art ccNUMA architectures, reasonably balanced page placement schemes-such as round-robin

Dimitrios S. Nikolopoulos; Theodore S. Papatheodorou; Constantine D. Polychronopoulos; Jesus Labarta; Eduard Ayguadé

2000-01-01

116

THE SPATIAL DISTRIBUTION OF STARS IN OPEN CLUSTERS  

SciTech Connect

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.

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

117

Water sample-collection and distribution system  

NASA Technical Reports Server (NTRS)

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

Brooks, R. R.

1978-01-01

118

Automatic software upgrades for distributed systems  

E-print Network

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 ...

Ajmani, Sameer, 1976-

2004-01-01

119

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

120

Research in Distributed Real-Time Systems  

NASA Technical Reports Server (NTRS)

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.

Mukkamala, R.

1997-01-01

121

Plasma confinement studies in open systems  

NASA Astrophysics Data System (ADS)

Studies in open systems in the world are reviewed from viewpoints of the potential confinement and magnetohydrodynamic (MHD) stability. The tandem mirror GAMMA 10 has shown the potential confinement of a high-ion-temperature plasma from an analysis of the time evolution of end-loss ion current and end-loss ion energy distributions. The central cell density was increased by 50% by the potential confinement. In the HIEI tandem mirror H-mode-like phenomena were observed with an increase in density and diamagnetic signal in a limiter biasing experiment. Potential formation phenomena in plasmas are studied by 0741-3335/41/3A/024/img1-like Upgrade under different magnetic field configurations and plasma conditions. The fully axisymmetric tandem mirror AMBAL-M is under construction and its end mirror system has been assembled. Heating experiments of a plasma gun produced plasma by neutral beam injection and ICRF heating are in progress. The gas dynamic trap (GDT) experiment has successfully produced an MHD-stable high-temperature, high-density plasma. In GOL-3-II, a high-density plasma with several 100 eV temperature is created by powerful relativistic electron beam injection. Construction of HANBIT has been completed and experiments on plasma production and ICRF heating have begun.

Yatsu, Kiyoshi

1999-03-01

122

WATER DISTRIBUTION SYSTEM OPERATION: APPLICATION OF  

E-print Network

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

Mays, Larry W.

123

Load balancing in homogeneous broadcast distributed systems  

Microsoft Academic Search

Three different load balancing algorithms for distributed systems that consist of a number of identical processors and a CSMA communication system are presented in this paper. Some of the properties of a multi-resource system and the balancing process are demonstrated by an analytic model. Simulation is used as a mean for studying the interdependency between the parameters of the distributed

Miron Livnyand; Myron Melman

1982-01-01

124

Intelligent Network Communications for Distributed Database Systems  

Microsoft Academic Search

Customizing network sites have become an increasingly important issue in distributed database systems. This will improve the network system performance by reducing the number of communications required for query processing in terms of retrieval and update transactions. This paper presents an intelligent clustering method for distributed database system that provides a structure for organizing large number of network sites into

Ismail Omar Hababeh

2010-01-01

125

Distributed multiparty desktop conferencing system: MERMAID  

Microsoft Academic Search

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

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

1990-01-01

126

Controls and Diagnostics for Air Distribution Systems  

Microsoft Academic Search

Fault detection and diagnostics applied to heating, ventilating, and air-conditioning (HVAC) equipment has been an active area of research over the past decade, with much of the work focusing on air distribution systems. Concurrent efforts have sought to im-prove the control of these systems. This paper discusses the relationship between controls and diagnostics for air distribution systems, provides an overview

Leslie K. Norford; Kwangduk Douglas Lee

2003-01-01

127

Heterogeneous distributed database systems for production use  

Microsoft Academic Search

It is increasingly important for organizations to achieve additional coordination of diverse computerized operations. To do so, it is necessary to have database systems that can operate over a distributed network and can encompass a heterogeneous mix of computers, operating systems, communications links, and local database management systems. This paper outlines approaches to various aspects of heterogeneous distributed data management

Gomer Thomas; Glenn R. Thompson; Chin-Wan Chung; Edward Barkmeyer; Fred Carter; Marjorie Templeton; Stephen Fox; Berl Hartman

1990-01-01

128

Intelligent Systems for Power Management and Distribution  

NASA Technical Reports Server (NTRS)

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

Button, Robert M.

2002-01-01

129

OPERATING SYSTEM SUPPORT FOR EASY DEVELOPMENT OF DISTRIBUTED FILE SYSTEMS  

Microsoft Academic Search

A number of new distributed file systems have been de- veloped, but the development of such file systems is not a simple task because it requires the operating system kernel to be modified. We have therefore developed the CAPELA operating system, which makes distributed file systems easy to develop. CAPELA allows the users to develop a file system as an

KENICHI KOURAI; SHIGERU CHIBA; TAKASHI MASUDA

1998-01-01

130

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

Code of Federal Regulations, 2010 CFR

...false Grounded distribution systems (Neutral grounded). 120...FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems (Neutral grounded)....

2010-10-01

131

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

Code of Federal Regulations, 2010 CFR

...false Grounded distribution systems (neutral grounded). 183...VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376 Grounded distribution systems (neutral grounded)....

2010-10-01

132

Supporting Object Migration in Distributed Systems  

Microsoft Academic Search

To fully support distributed processing in any distributed system, it must be possible to perform remote executions. For maximum benefit, this should also be coupled with the movement of data and programs from sites other than those where the execution is to be performed. Such distributed processing requirements are considered in the context of a Virtual Enterprise which uses an

George Semeczko; Stanley Y. W. Su

1997-01-01

133

Programming languages for distributed computing systems  

Microsoft Academic Search

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

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

1989-01-01

134

Randomized control of open quantum systems  

E-print Network

The problem of open-loop dynamical control of generic open quantum systems is addressed. In particular, I focus on the task of effectively switching off environmental couplings responsible for unwanted decoherence and dissipation effects. After revisiting the standard framework for dynamical decoupling via deterministic controls, I describe a different approach whereby the controller intentionally acquires a random component. An explicit error bound on worst-case performance of stochastic decoupling is presented.

Lorenza Viola

2006-01-16

135

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

E-print Network

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 ...

Piña, Alexander L

2014-01-01

136

Quantum arrival time for open systems  

SciTech Connect

We extend previous work on the arrival time problem in quantum mechanics, in the framework of decoherent histories, to the case of a particle coupled to an environment. The usual arrival time probabilities are related to the probability current, so we explore the properties of the current for general open systems that can be written in terms of a master equation of the Lindblad form. We specialize to the case of quantum Brownian motion, and show that after a time of order the localization time of the current becomes positive. We show that the arrival time probabilities can then be written in terms of a positive operator-valued measure (POVM), which we compute. We perform a decoherent histories analysis including the effects of the environment and show that time-of-arrival probabilities are decoherent for a generic state after a time much greater than the localization time, but that there is a fundamental limitation on the accuracy {delta}t, with which they can be specified which obeys E{delta}t>>({h_bar}/2{pi}). We confirm that the arrival time probabilities computed in this way agree with those computed via the current, provided there is decoherence. We thus find that the decoherent histories formulation of quantum mechanics provides a consistent explanation for the emergence of the probability current as the classical arrival time distribution, and a systematic rule for deciding when probabilities may be assigned.

Yearsley, J. M. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

2010-07-15

137

Quantum Arrival Time For Open Systems  

E-print Network

We extend previous work on the arrival time problem in quantum mechanics, in the framework of decoherent histories, to the case of a particle coupled to an environment. The usual arrival time probabilities are related to the probability current, so we explore the properties of the current for general open systems that can be written in terms of a master equation of Lindblad form. We specialise to the case of quantum Brownian motion, and show that after a time of order the localisation time the current becomes positive. We show that the arrival time probabilities can then be written in terms of a POVM, which we compute. We perform a decoherent histories analysis including the effects of the environment and show that time of arrival probabilities are decoherent for a generic state after a time much greater than the localisation time, but that there is a fundamental limitation on the accuracy, $\\delta t$, with which they can be specified which obeys $E\\delta t>>\\hbar$. We confirm that the arrival time probabilities computed in this way agree with those computed via the current, provided there is decoherence. We thus find that the decoherent histories formulation of quantum mechanics provides a consistent explanation for the emergence of the probability current as the classical arrival time distribution, and a systematic rule for deciding when probabilities may be assigned.

J. M. Yearsley

2010-03-31

138

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 centerâÂÂs 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 centerâÂÂs 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.

139

The Digital Distributed System Security Architecture  

Microsoft Academic Search

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

Andy Goldstein; Butler Lampson; Charlie Kaufman; Morrie Gasser

1989-01-01

140

Key distribution system based on identification information  

Microsoft Academic Search

A key distribution system (KDS) based on identification information (ID-based KDS) is presented. The system is founded on the Diffie-Hellman public key distribution scheme and has an identity authentication function. It uses an individual user's identification information instead of the public file used in the Diffie-Hellman scheme. It does not require any services of a center to distribute work keys

EIJI OKAMOTO; KAZUE TANAKA

1989-01-01

141

Diagnosing delivery problems in the White House Information Distribution System  

SciTech Connect

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.

Nahabedian, M.; Shrobe, H.

1996-12-31

142

DISTRIBUTED HYDROGEN FUELING SYSTEMS ANALYSIS  

Microsoft Academic Search

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

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

2001-01-01

143

Specification of Secure Distributed Collaboration Systems  

Microsoft Academic Search

The focus of this paper is on a specification model for defining security and coordination policies for distributed collaboration and workflow systems. This work is motivated by the objective to build distributed collaboration systems from their high level specifications. We identify here unique requirements for secure collaboration, specifically role ad- mission and activation constraints, separation of duties, dy- namic access

Anand R. Tripathi; Tanvir Ahmed; Richa Kumar

2003-01-01

144

Distributed Learning Companion System: WEST Revisited  

Microsoft Academic Search

This paper describes a distributed learning system which consists of two connected computers so that students can learn in collaboration and\\/or competition at different locations. Considering different numbers and roles of involved agents, we have enumerated 768 possible distributed learning models. Among them, we evaluated 3 models using a system which is a reimplementation of the well-known WEST program. The

Tak-wai Chan; I-ling Chung; Rong-guey Ho; Wen-juan Hou; Ging-long Lin

1992-01-01

145

Functional Analysis of Manufacturing Execution System Distribution  

Microsoft Academic Search

Manufacturing Execution Systems are essential elements for vertical integration in modern automation systems because they provide the link between the centralized enterprise level and the distributed shop floor. Existing centralized MES implementations can however not properly cope with an unpre- dictable order flow, changes on the shop floor, or the increasing complexity of both. Distribution of the MES functionalities would

Aleksey Bratukhin; Thilo Sauter

2011-01-01

146

Simulation of Distributed Systems Fernando G. Gonzalez  

E-print Network

Simulation of Distributed Systems Fernando G. Gonzalez School of Electrical Engineering@pegasus.cc.ucf.edu Keywords: discrete event simulation, single threaded simulation, discrete event control Abstract This paper in a single threaded simulation. It is assumed that the distributed system is described by a collection

Gonzalez, Fernando

147

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...

148

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...

149

A scalable distributed information management system  

Microsoft Academic Search

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

Praveen Yalagandula; Mike Dahlin

2004-01-01

150

A scalable distributed information management system  

Microsoft Academic Search

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

Praveen Yalagandula; Michael Dahlin

2004-01-01

151

Variational Functions in Open Systems  

NASA Astrophysics Data System (ADS)

This paper looks for an entropy-like quantity having a monotonic time development. In the case of spontaneous emission, the final state usually consists of a single ground state assigning zero to the ordinary expressions for entropy. Thus entropy ceases to be a monotonic measure of the direction of time. The point is illustrated by a simple test case consisting of three levels coupled by spontaneous emission. It is shown how this case allows the definition of a monotonic function. Using the theory of non-Hermitian operators, the paper shows how such a function may be constructed in the general case, and it explores the main consequences of the expressions suggested. The generalization of the entropy concept is found to relate to time-reversal properties of the dynamics. The paper concludes by discussing open questions and possible further explorations.

Stenholm, Stig

2002-12-01

152

Open Hardware for CERN's accelerator control systems  

NASA Astrophysics Data System (ADS)

The accelerator control systems at CERN will be upgraded and many electronics modules such as analog and digital I/O, level converters and repeaters, serial links and timing modules are being redesigned. The new developments are based on the FPGA Mezzanine Card, PCI Express and VME64x standards while the Wishbone specification is used as a system on a chip bus. To attract partners, the projects are developed in an `Open' fashion. Within this Open Hardware project new ways of working with industry are being evaluated and it has been proven that industry can be involved at all stages, from design to production and support.

van der Bij, E.; Serrano, J.; Wlostowski, T.; Cattin, M.; Gousiou, E.; Alvarez Sanchez, P.; Boccardi, A.; Voumard, N.; Penacoba, G.

2012-01-01

153

Open quantum systems with loss and gain  

E-print Network

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.

Hichem Eleuch; Ingrid Rotter

2014-09-09

154

THINK: a secure distributed systems architecture  

Microsoft Academic Search

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

Christophe Rippert; Jean-bernard Stefani

2002-01-01

155

Resource Management for Distributed Parallel Systems  

NASA Technical Reports Server (NTRS)

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.

Neuman, B. Clifford; Rao, Santosh

1993-01-01

156

An Open Market-Based Architecture for Distributed Computing  

Microsoft Academic Search

One of the c hallenges in large scale distributed computing is to utilize the thousands of idle personal computers. In this\\u000a paper, we presen t a system that enables users to effortlessly and safely export their machines in a global market of processing\\u000a capacity. Efficient resource allocation is performed based on statistical machine profiles and leases are used to promote

Spyros Lalis; Alexandros Karypidis

2000-01-01

157

User Registration Systems for Distributed Systems  

Microsoft Academic Search

As NASA's Earth Observing System Data and Information System (EOSDIS) systems have evolved over the years, most of the EOSDIS data are now available to users via anonymous on-line access. Although the changes have improved the dissemination efficiency of earth science data, the anonymous access has made it difficult to characterize users, capture metrics on the value of EOSDIS and

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

2010-01-01

158

Compositional Modeling of Reactive Systems Using Open Nets  

Microsoft Academic Search

In order to model the behaviour of open concurrent systems by means of Petri nets, we introduce open Petri nets, a generalization of the ordinary model where some places, designated as open, represent an interface of the system towards the environment. Besides generalizing the token game to reflect this extension, we define a truly concurrent semantics for open nets by

Paolo Baldan; Andrea Corradini; Hartmut Ehrig; Reiko Heckel

2001-01-01

159

Open system approach to neutrino oscillations  

E-print Network

Neutrino oscillations are studied in the general framework of open quantum systems by means of extended dynamics that take into account possible dissipative effects. These new phenomena induce modifications in the neutrino oscillation pattern that in general can be parametrized by means of six phenomenological constants. Although very small, stringent bounds on these parameters are likely to be given by future planned neutrino experiments.

F. Benatti; R. Floreanini

2000-02-21

160

Data Architecture in an Open Systems Environment.  

ERIC Educational Resources Information Center

The conceptual basis for structured data architecture, and its integration with open systems technology at Indiana University, are described. Key strategic goals guiding these efforts are discussed: commitment to improved data access; migration to relational database technology, and deployment of a high-speed, multiprotocol network; and…

Bernbom, Gerald; Cromwell, Dennis

1993-01-01

161

Centralised and distributed electricity systems  

Microsoft Academic Search

Because of their high level of integration, centralised energy supply systems are vulnerable to disturbances in the supply chain. In the case of electricity especially, this supply paradigm is losing some of its appeal. Apart from vulnerability, a number of further aggravating factors are reducing its attractiveness. They include the depletion of fossil fuels and their climate change impact, the

François Bouffard; Daniel S. Kirschen

2008-01-01

162

Multiagent Systems Multiagent systems are distributed computing systems. Like all distributed  

E-print Network

operational definition of intelligent systems one that is inspired by the works of McCarthy [1979], Newell of computer science. It tells us that our intuitive conception of intelligence yields some nice abstractions classical distributed systems they, and their constituent en- tities, are intelligent. I shall adopt as my

163

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...

164

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...

165

PERFORMANCE ANALYSIS OF DISTRIBUTED DATA BASE SYSTEMS  

E-print Network

the design of a distributed relational data base system. Then, we dis- cuss experimental observations distribute E at Berkeley where E.dept = "shoe" at Paris where E.dept = "toy" at Boston where E.dept != "toy" and E.dept != "shoe" Berkeley, Paris and Boston are logical names of machines which are mapped to site

California at Irvine, University of

166

The Space Shuttle audio distribution system  

NASA Astrophysics Data System (ADS)

The Space Shuttle Orbiter's Audio Distribution System (ADS) provides voice communication among crew members and an interface to various radio access functions and hardline functions associated with a given orbital mission's payloads. The ADS encompasses facilities for audio processing, mixing, amplification, volume control, isolation, switching, and distribution. Attention is given to ADS design features and interface possibilities.

Lee, R. K. P.

167

Parallel and Distributed System Simulation  

NASA Technical Reports Server (NTRS)

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

Dongarra, Jack

1998-01-01

168

Accounting and Accountability for Distributed and Grid Systems  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

169

Reasoning about Asynchronous Behaviour in Distributed Systems  

Microsoft Academic Search

When a new component is added to an existing, distributed system, it has to co-operate with existing components in a way that doesn't interfere badly with the original system. Adding new components to an existing system is simplified if their communication is asynchronous. It allows for looser cou- pling. Unfortunately, the fact that the communication between components is asynchronous adds

Peter Henderson

2002-01-01

170

High speed quantum key distribution system  

Microsoft Academic Search

Quantum key distribution (QKD) systems can generate unconditionally secure common key between remote users. Improvement of QKD performance, particularly on key generation rate, has been required to meet current network traffic. The present paper considers system requirement to improve key generation rate by increasing photon detection rate and reducing error rate. A high-speed QKD system should be equipped with low

Akihisa Tomita; Ken-Ichiro Yoshino; Yoshihiro Nambu; Akio Tajima; Akihiro Tanaka; Seigo Takahashi; Wakako Maeda; Shigehito Miki; Zhen Wang; Mikio Fujiwara; Masahide Sasaki

2010-01-01

171

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 for railway lines is developed. The formal specification language is used to ensure correctness and safety

172

An adaptive distributed workflow system framework  

Microsoft Academic Search

Workflow management systems are increasingly used to assist the automation of business processes that involve the exchange of documents, information, or task execution results. Recent developments in distributed information system technology now make it possible to extend the workflow management system idea to much wider spheres of activity in the industrial and commercial world. This paper describes a framework under

Martin K. Purvis; Maryam Purvis; Selena Lemalu

2000-01-01

173

A DISTRIBUTED AUTOMATION SYSTEM FOR ELECTROPHYSICAL INSTALLATIONS  

E-print Network

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

Kozak, Victor R.

174

Transitionless quantum driving in open quantum systems  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

175

An Open Source Power System Analysis Toolbox  

Microsoft Academic Search

This paper describes the Power System Analysis Toolbox (PSAT), an open source Matlab and GNU\\/Octave-based software package for analysis and design of small to medium size electric power systems. PSAT includes power flow, continuation power flow, optimal power flow, small-signal stability analysis, and time-domain simulation, as well as several static and dynamic models, including nonconventional loads, synchronous and asynchronous machines,

Federico Milano

2005-01-01

176

Secure resilient high performance file system for distributed systems  

Microsoft Academic Search

While client server distributed file systems, such as NFS (Network File System) or Sprite, do not scale with respect to the number of clients and exhibit a single point of failure, our work in this paper has the potential to cope with an increasing number of participants. Although most of the current distributed file systems ensure authentication and file access

Sunil Chakravarthy; Chittaranjan Hota

2010-01-01

177

Statistics of eigenfunctions in open chaotic systems: a perturbative approach  

E-print Network

We investigate the statistical properties of the complexness parameter which characterizes uniquely complexness (biorthogonality) of resonance eigenstates of open chaotic systems. Specifying to the regime of isolated 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 r\\^ole of spectral fluctuations.

Charles Poli; Dmitry Savin; Olivier Legrand; Fabrice Mortessagne

2009-06-30

178

Adaption in distributed systems: an evolutionary approach  

Microsoft Academic Search

ABSTRACT There is a trend towards networked and distributed systems, com- plicating the design process of self-adaptive software. Logistics networks,can be seen as a distributed system,that have to adapt to requirements of companies,and customers in a flexible and fast manner. When constructing and planning logistic networks differ- ent aspects of complexity,have to be considered: the number,of stores, intermediate stores and

Stephan Otto; Stefan Kirn

2006-01-01

179

Distributed Architectures for Event-Based Systems  

Microsoft Academic Search

\\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

Valentin Cristea; Florin Pop; Ciprian Dobre; Alexandru Costan

180

Examination and characterization of distribution system biofilms.  

PubMed Central

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

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

1987-01-01

181

Strategy Guideline: Compact Air Distribution Systems  

SciTech Connect

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.

Burdick, A.

2013-06-01

182

Open Source Real Time Operating Systems Overview  

SciTech Connect

Modern control systems applications are often built on top of a real time operating system (RTOS) which provides the necessary hardware abstraction as well as scheduling, networking and other services. Several open source RTOS solutions are publicly available, which is very attractive, both from an economic (no licensing fees) as well as from a technical (control over the source code) point of view. This contribution gives an overview of the RTLinux and RTEMS systems (architecture, development environment, API etc.). Both systems feature most popular CPUs, several APIs (including Posix), networking, portability and optional commercial support. Some performance figures are presented, focusing on interrupt latency and context switching delay.

Straumann, Till

2001-12-11

183

Heterogeneous distributed query processing: The DAVID system  

NASA Technical Reports Server (NTRS)

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.

Jacobs, Barry E.

1985-01-01

184

Detecting Flow Anomalies in Distributed Systems  

E-print Network

Deep within the networks of distributed systems often contain anomalies that affect its efficiency and performance. These anomalies are difficult to detect because the distributed systems may not have sufficient sensors to monitor the flow of traffic within the interconnected nodes of the networks. Without early detection and making corrections, these anomalies may aggravate over time and could possibly cause disastrous outcomes in the system in the unforeseeable future. Using only coarse-grained information from the two end points of network flows, we propose a network transmission model and a localization algorithm, to detect the location of anomalies and rank them using a proposed metric within distributed systems. We evaluate our approach on passengers' records of an urbanized city's public transportation system and correlate our findings with passengers' postings on social media microblogs. Our experiments show that the metric derived using our localization algorithm gives a better ranking of anomalies a...

Chua, Freddy Chong Tat; Huberman, Bernardo A

2014-01-01

185

Modeling and planning distributed energy systems online  

NASA Astrophysics Data System (ADS)

Sustainable energy is a core concern worldwide for the foreseeable future. Technologically, its key trends are distributed and renewable energy resources and smart grid capabilities. At the same time, a global need for sustainable energy is meeting increasingly diverse energy policy and economics. To plan with such complex contexts and systems, a novel distributed energy software tool and its initial implementation is presented: the Energy Systems Evaluator Online (ESEO). Its contributions include: (1) A flexible model framework that can simulate current and expected distributed energy systems; (2) An architecture specifying the modular design needed for distributed energy planning software in general; (3) A working implementation as the first general energy planning tool deployed via the Internet with collaborative capabilities.

Wieler, Susana

186

Experimental studies of a phase identification system for distribution systems  

Microsoft Academic Search

This paper presents the design and development of experimental set-ups for the purpose of testing phase identification systems for power distribution networks. A series of hardware experiments and procedures were created within a laboratory environment at Drexel University to represent actual, distribution components and multiple operating conditions. These tests included multiple transformer connection types including Wye, Delta and Scott-T, distribution

Thomas Dunmore; Eric Jaffe; Sean Kennedy; Dhruv M. Patel; Preet Soni; Michael Kleinberg; Karen Miu

2010-01-01

187

Cooperative Autonomic Management in Dynamic Distributed Systems  

NASA Astrophysics Data System (ADS)

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

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

188

Adiabatic quantum computation in open systems.  

PubMed

We analyze the performance of adiabatic quantum computation (AQC) subject to decoherence. To this end, we introduce an inherently open-systems approach, based on a recent generalization of the adiabatic approximation. In contrast to closed systems, we show that a system may initially be in an adiabatic regime, but then undergo a transition to a regime where adiabaticity breaks down. As a consequence, the success of AQC depends sensitively on the competition between various pertinent rates, giving rise to optimality criteria. PMID:16384441

Sarandy, M S; Lidar, D A

2005-12-16

189

Feynman's Clock for open quantum systems  

E-print Network

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.

David G. Tempel; Alan Aspuru-Guzik

2014-06-21

190

Architectural Design of Adaptive Distributed Multimedia Systems  

E-print Network

for remote access to News­on­Demand. This system allows the user to remotely access a multimedia database distributed multimedia system for remote access to multimedia databases. This design focuses on the aspects, such as network or server congestion. We present in this paper an abstract architectural design of our adaptive

von Bochmann, Gregor

191

Detection of Mutual Inconsistency in Distributed Systems  

Microsoft Academic Search

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

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

192

High Speed Quantum Key Distribution System  

Microsoft Academic Search

Quantum key distribution (QKD) systems can generate unconditionally secure common keys between remote users. Improvements of QKD performance, particularly in key generation rate, have been required to meet current network traffic. A high-speed QKD system should be equipped with low-loss receivers with high visibility, highly efficient photon detectors with small dark count probability. A solution to these issues is to

Akio Tajima; Akihiro Tanaka; Seigo Takahashi; Ken-Ichiro Yoshino; Yoshihiro Nambu

2010-01-01

193

Design Considerations for Distributed Microsensor Systems  

Microsoft Academic Search

Wireless distributed microsensor systems will enable the reliable monitoring and control of a variety of applica- tions that range from medical and home security to machine diagnosis, chemical\\/biological detection and other military applications. The sensors have to be designed in a highly integrated fashion, optimizing across all levels of system abstraction, with the goal of minimiz- ing energy dissipation. This

Anantha Chandrakasan; Rajeevan Amirtharajah; SeongHwan Cho; James Goodman; Gangadhar Konduri; Joanna Kulik; Wendi Rabiner; Alice Wang

2000-01-01

194

Design considerations for distributed microsensor systems  

Microsoft Academic Search

Wireless distributed microsensor systems will enable the reliable monitoring and control of a variety of applications that range from medical and home security to machine diagnosis, chemical\\/biological detection and other military applications. The sensors have to be designed in a highly integrated fashion, optimizing across all levels of system abstraction, with the goal of minimizing energy dissipation. This paper addresses

Anantha Chandrakasan; Rajeevain Amirtharajah; Seonghwan Cho; James Goodman; Gangadhar Konduri; Joanna Kulik; Wendi Rabiner; Alice Wang

1999-01-01

195

Policy Driven Management for Distributed Systems  

Microsoft Academic Search

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

Morris Sloman

1994-01-01

196

Speculative Execution in a Distributed File System  

E-print Network

System to provide the consistency of single-copy file semantics and the safety of synchronous I/O, yet still outperform current distributed file systems with weaker consistency and safety. Categories' address: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI

Chen, Peter M.

197

Developing a distributed system for infrastructure protection  

Microsoft Academic Search

Your business increasingly relies on computer-controlled systems vulnerable to intrusion and destruction. The recent distributed denial of service attacks against e-commerce companies showed that this vulnerability extends beyond your own corporate networks: the very infrastructure of the Internet is at risk. When infoterrorists use the networks' high connectivity and low security to launch attacks against critical information infrastructure systems, they

G. Cybenko; Guofei Jiang

2000-01-01

198

Distributed Diagnosis of Networked Hybrid Systems  

Microsoft Academic Search

Networked embedded systems are composed of a large num- ber of distributed nodes that interact with the physical world via a set of sensors and actuators, have their own computa- tional capabilities, and communicate with each other via a wired or wireless network. Diagnostic systems for such ap- plications must address new challenges caused by the dis- tribution of resources,

James Kurien; Xenofon D. Koutsoukos; Zhao Feng

2002-01-01

199

Experiences with the Amoeba distributed operating system  

Microsoft Academic Search

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

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

1990-01-01

200

Understanding fault-tolerant distributed systems  

Microsoft Academic Search

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

Flavin Cristian

1991-01-01

201

Cost and Performance of Distributed Photovoltaic Systems  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

202

Dynamic operation of a photovoltaic system connected to distribution system  

Microsoft Academic Search

In this paper, a photovoltaic (PV) system which is connected to a distribution grid is simulated in MATLAB\\/Simulink. The photovoltaic module is modeled with Lorenzo mathematical model. A DC\\/DC boost is used to enhance voltage up to the favorite level and a SPWM inverter connects it to the distribution system. There are several controllers which their tasks are power flow

S. M. Ale-Emran; M. Abedi; G. B. Gharehpetian; R. Noroozian

2008-01-01

203

Effective Hamiltonian approach to adiabatic approximation in open systems  

E-print Network

The adiabatic approximation in open systems is formulated through the effective Hamiltonian approach. By introducing an ancilla, we embed the open system dynamics into a non-Hermitian quantum dynamics of a composite system, the adiabatic evolution of the open system is then defined as the adiabatic dynamics of the composite system. Validity and invalidity conditions for this approximation are established and discussed. A High-order adiabatic approximation for open systems is introduced. As an example, the adiabatic condition for an open spin-$\\frac 1 2$ particle in time-dependent magnetic fields is analyzed.

X. X. Yi; D. M. Tong; L. C. Kwek; C. H. OH

2006-06-24

204

Periodically driven quantum open systems: Tutorial  

E-print Network

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.

Robert Alicki; David Gelbwaser-Klimovsky; Gershon Kurizki

2012-05-21

205

Periodically driven quantum open systems: Tutorial  

E-print Network

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.

Alicki, Robert; Kurizki, Gershon

2012-01-01

206

Exploiting virtual synchrony in distributed systems  

NASA Technical Reports Server (NTRS)

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.

Birman, Kenneth P.; Joseph, Thomas A.

1987-01-01

207

Distributed Storage Systems for Data Intensive Computing  

SciTech Connect

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.

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

2012-01-01

208

Multicommodity Distribution System Design by Benders Decomposition * † ‡  

Microsoft Academic Search

\\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

A. M. Geoffrion

209

Voltage control integrated in distribution management system  

Microsoft Academic Search

The voltage control in distribution networks is established as a centralized analytical function in this paper. It is integrated in the Distribution Management System. Control devices consist of under-load and off-voltage tap changing transformers, feeder voltage regulators and buck\\/boost transformers. On the basis of areas whose voltages are influenced by these control devices and their action speeds, the voltage control

Vladimir C. Strezoski; Nenad A. Katic; Dusan S. Janjic

2001-01-01

210

An Open System for Intravascular Ultrasound Imaging  

PubMed Central

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

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

211

Fragment distributions for highly charged systems  

SciTech Connect

Charge and transverse energy distributions for intermediate mass fragments have been extracted for central {sup 84}Kr+{sup 197}Au collisions at E/A=35{minus}400 MeV. The slopes of the measured fragment charge distributions decrease monotonically with incident energy, consistent with the expectations for highly charged systems, but not with recent critical exponent analyses. Statistical model calculations, which reproduce the experimental trends, suggest that post-breakup fragment secondary decays alter significantly the observed charge distributions. Radial expansion velocities extracted from these calculations follow the systematics of Au+Au collisions. {copyright} {ital 1997} {ital The American Physical Society}

Williams, C.; Lynch, W.G.; Schwarz, C.; Tsang, M.B.; Hsi, W.C.; Huang, M.J.; Bowman, D.R.; Dinius, J.; Gelbke, C.K.; Handzy, D.O.; Kunde, G.J.; Lisa, M.A.; Peaslee, G.F.; Phair, L. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)] [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Botvina, A. [Institute for Nuclear Research, 117312 Moscow (Russia)] [Institute for Nuclear Research, 117312 Moscow (Russia); Lemaire, M.; Souza, S.R. [Laboratoire National SATURNE, CEN Saclay, 91191 Gif-sur-Yvette (France)] [Laboratoire National SATURNE, CEN Saclay, 91191 Gif-sur-Yvette (France); Van Buren, G.; Charity, R.J.; Sobotka, L.G. [Department of Chemistry, Washington University, St. Louis, Missouri 63130 (United States)] [Department of Chemistry, Washington University, St. Louis, Missouri 63130 (United States); Lynen, U.; Pochodzalla, J.; Sann, H.; Trautmann, W. [Gesellschaft fuer Schwerionenforschung, D-64220 Darmstadt 11 (Germany)] [Gesellschaft fuer Schwerionenforschung, D-64220 Darmstadt 11 (Germany); Fox, D.; de Souza, R.T. [Department of Chemistry and IUCF, Indiana University, Bloomington, Indiana 47405 (United States)] [Department of Chemistry and IUCF, Indiana University, Bloomington, Indiana 47405 (United States); Carlin, N. [Instituto de Fisica, Universidade de Sao Paulo, CEP 01498, Sao Paulo (Brazil)] [Instituto de Fisica, Universidade de Sao Paulo, CEP 01498, Sao Paulo (Brazil)

1997-05-01

212

Neutral particle beam distributed data acquisition system  

SciTech Connect

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.

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

1987-01-01

213

Open quantum systems and Dicke superradiance  

NASA Astrophysics Data System (ADS)

We study generic features of open quantum systems embedded into a continuum of scattering wavefunctions and compare them with results discussed in optics. A dynamical phase transition may appear at high level density in a many-level system and also in a two-level system if the coupling W to the environment is complex and sufficiently large. Here nonlinearities occur. When W ij is imaginary, two singular (exceptional) points may exist. In the parameter range between these two points, width bifurcation occurs as function of a certain external parameter. A unitary representation of the S matrix allows to calculate the cross section for a two-level system, including at the exceptional point (double pole of the S matrix). The results obtained for the transition of level repulsion at small (real) W ij to width bifurcation at large (imaginary) W ij show qualitatively the same features that are observed experimentally in the transition from Autler-Townes splitting to electromagnetically induced transparency in optics. Fermi's golden rule holds only below the dynamical phase transition while it passes into an anti-golden rule beyond this transition. The results are generic and can be applied to the response of a complex open quantum system to the action of an external field (environment). They may be considered as a guideline for engineering and manipulating quantum systems in such a way that they can be used for applications with special requirements.

Eleuch, Hichem; Rotter, Ingrid

2014-03-01

214

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

NASA Astrophysics Data System (ADS)

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-dimensional 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 phase trajectories of the mean and coefficient of variation of vertically integrated variables such as liquid water path align on one trajectory. This could be used as a diagnostic tool for global analyses of the statistics of closed- and open-cell occurrence and transitions between them.

Yamaguchi, T.; Feingold, G.

2014-10-01

215

Open-System Dynamics of Entanglement  

E-print Network

One of the greatest challenges in quantum information processing is the coherent control over quantum systems with an ever increasing number of particles. Within this endeavor, the harnessing of many-body entanglement against the effects of the environment is a pressing issue. Besides being an important concept from a fundamental standpoint, entanglement is recognized as a crucial resource for performance enhancements over classical methods. Understanding and controlling many-body entanglement in open systems may have implications in quantum computing, quantum simulations, secure quantum communication, quantum metrology, our understanding of the quantum-to-classical transition, and other important questions of quantum foundations. Here we present an overview of recent theoretical and experimental efforts to underpin the dynamics of entanglement in open quantum systems. Entanglement is taken as a dynamic quantity, and we survey how it evolves due to the interaction of the entangled system with its surroundings. We analyze several scenarios, corresponding to different families of states and environments, which render a diversity of dynamical behaviors. Contrary to single-particle quantities, that typically vanish only asymptotically in time, entanglement may disappear at a finite time. Moreover, important classes of entanglement show an exponential decay with the system size when subject to local noise, posing yet another threat to the already challenging scaling of quantum technologies. Results for the local and global noise cases are summarized. Robustness-enhancement techniques, scaling laws, statistical and geometrical aspects of multipartite-entanglement decay are also reviewed; all in order to give a broad picture of entanglement dynamics in open quantum systems addressed to both theorists and experimentalists inside and outside the field of quantum information.

Leandro Aolita; Fernando de Melo; Luiz Davidovich

2014-02-15

216

Cardea: Dynamic Access Control in Distributed Systems  

NASA Technical Reports Server (NTRS)

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.

Lepro, Rebekah

2004-01-01

217

Evolution of Quantum Entanglement in Open Systems  

SciTech Connect

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable entanglement for a system consisting of two uncoupled harmonic oscillators interacting with a thermal environment. Using Peres-Simon necessary sufficient criterion for separability of two-mode Gaussian states, we show that for some values of diffusion coefficient, dissipation constant and temperature of the environment, the state keeps for all times its initial type: separable or entangled. In other cases, entanglement generation, entanglement sudden death or a periodic collapse revival of entanglement take place.

Isar, A. [National Institute of Physics Nuclear Engineering, Bucharest-Magurele, P.O. Box MG-6 (Romania)

2010-08-04

218

Modelling Root Systems Using Oriented Density Distributions  

NASA Astrophysics Data System (ADS)

Root architectural models are essential tools to understand how plants access and utilize soil resources during their development. However, root architectural models use complex geometrical descriptions of the root system and this has limitations to model interactions with the soil. This paper presents the development of continuous models based on the concept of oriented density distribution function. The growth of the root system is built as a hierarchical system of partial differential equations (PDEs) that incorporate single root growth parameters such as elongation rate, gravitropism and branching rate which appear explicitly as coefficients of the PDE. Acquisition and transport of nutrients are then modelled by extending Darcy's law to oriented density distribution functions. This framework was applied to build a model of the growth and water uptake of barley root system. This study shows that simplified and computer effective continuous models of the root system development can be constructed. Such models will allow application of root growth models at field scale.

Dupuy, Lionel X.

2011-09-01

219

Tsallis Entropy Based Velocity Distribution in Open Channel Flows  

E-print Network

Page 16 Relation of H(u) to uD and ?1 ...................................................................... 54 17 Velocity distribution and curvilinear coordinate system ........................... 60 18 Typical isovel pattern indication location... and Chien 1955) Iran Data 1 (Afzalmehr 2008) ?1 ?v ?1 ?v ?1 ?v uD=9.194 ft/s um=7.303 ft/s uD=11.42ft/s um=8.7ft/s uD=0.535 m/s um=0.412 m/s 1/4 -0.33 0.672 -6.473 0.528 -6.489 1.190 -0.680 1/3 -0.50 0.746 -7.354 0.576 -7.289 1.675 -0.984 2/3 -2...

Luo, Hao

2010-07-14

220

On-Site Wastewater Treatment Systems: Spray Distribution  

E-print Network

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...

Lesikar, Bruce J.

1999-09-06

221

Mercury- Distributed Metadata Management, Data Discovery and Access System  

NASA Astrophysics Data System (ADS)

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.

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

2007-12-01

222

Measurements over distributed high performance computing and storage systems  

NASA Technical Reports Server (NTRS)

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.

Williams, Elizabeth; Myers, Tom

1993-01-01

223

49 CFR 191.13 - Distribution systems reporting transmission pipelines; transmission or gathering systems...  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Distribution systems reporting transmission pipelines; transmission or gathering systems reporting distribution...191.13 Distribution systems reporting transmission pipelines; transmission or gathering...

2011-10-01

224

49 CFR 191.13 - Distribution systems reporting transmission pipelines; transmission or gathering systems...  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Distribution systems reporting transmission pipelines; transmission or gathering systems reporting distribution...191.13 Distribution systems reporting transmission pipelines; transmission or gathering...

2012-10-01

225

49 CFR 191.13 - Distribution systems reporting transmission pipelines; transmission or gathering systems...  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Distribution systems reporting transmission pipelines; transmission or gathering systems reporting distribution...191.13 Distribution systems reporting transmission pipelines; transmission or gathering...

2010-10-01

226

Distributed intrusion detection system based on ARTIS  

NASA Astrophysics Data System (ADS)

Traditional IDS (Intrusion Detection System) performs detection by matching the sample pattern with the intrusion pattern that has been defined, as a result the IDS loses the diversity and the self-adaptation and can not detect the variation intrusion and the unknown intrusion. This paper gives a distributed intrusion detection approach based on the Artificial Immune System. It defines the Self, Nonself and immune cell and builds an intrusion detection model composed of memory cell, mature cell and immature cell and also gives the environment definition, matching rule, training detection system, immune regulation and memory, monitor generation and so on. The result of the experiment show that this intrusion detection system model has the characters of distributed, error tolerance, dynamic learning, adaptation and this approach is efficient to the network intrusion detection.

Qiao, Peili; Su, Jie; Sun, Chengwei

2005-03-01

227

Sprint Driven Development: Agile Methodologies in a Distributed Open Source Project (PyPy)  

Microsoft Academic Search

This paper describes the practices created, adopted and evolved in a Distributed Open Source Project (PyPy) project. PyPy\\u000a is a hybrid project, combining the different aspects of Agile and Distributed Development within the context of an Open Source\\u000a community. The project is partially funded by the European Commission through the 6th Framework Program. Influences and adoptions\\u000a of techniques such as

2006-01-01

228

Distributed-aperture infrared sensor systems  

Microsoft Academic Search

The on-going maturation of electro-optic technology in which the advent of third generation focal plane array is being combined with the capabilities of increasingly powerful signal processing algorithm now points to a new direction in design of electro-optic sensor system for both military and non-military applications. Taking advantage of those advances. Distributed Aperture IR Sensor systems (DAIRS) are currently in

Thomas C. Brusgard

1999-01-01

229

Programming model for distributed intelligent systems  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

230

Energy Efficiency of Distributed Environmental Control Systems  

Microsoft Academic Search

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

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

2011-01-01

231

Request Redirection Algorithms for Distributed Web Systems  

Microsoft Academic Search

Replication of information among multiple servers is necessary to support high request rates to pop- ular Web sites. We consider systems that maintain one interface to the users even if they consist of multiple nodes with visible IP addresses that are distribut ed among different networks. In these sys- tems, the first-level dispatching is achieved through the Do main Name

Valeria Cardellini; Michele Colajanni; Philip S. Yu

2003-01-01

232

Workflow management in large distributed systems  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

233

Interfaces for Distributed Systems of Information Servers.  

ERIC Educational Resources Information Center

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

Kahle, Brewster M.; And Others

1993-01-01

234

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...

235

Microfluidic distribution system Antonin Hoel1  

E-print Network

of years, matrix of microneedles have been proposed as an in- novative tool to enhance transdermal drug of drug through 100 microneedles distributed over one square centimetre. 2 Introduction Since a decade resistance, such a system should not permit to control the quantity of drug that is injected through each

Paris-Sud XI, Université de

236

STANDARDIZED COST FOR WATER SUPPLY DISTRIBUTION SYSTEMS  

EPA Science Inventory

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

237

Genuine atomic multicast in asynchronous distributed systems  

Microsoft Academic Search

This paper addresses the problem of atomic multicasting messages in asynchronous distributed systems. Firstly, we give a characterization of the notion of genuine atomic multicast. This characterization leads to a better understanding of the difference between atomic multicast and atomic broadcast, and to make a clear distinction between genuine atomic multicast algorithms and non-genuine atomic multicast algorithms. Secondly, we consider

Rachid Guerraoui; André Schiper

2001-01-01

238

The Topaz System: Distributed Multiprocessor Personal Computing  

E-print Network

this paper, we give a brief overview of Topaz, and then make some observations based on our use of the system and our plans for the future. These observations fall into two areas: our experience with multiprocessing in a workstation, and our views on distribution and autonomy. 2 Topaz overview

Paul McJones; Andy Hisgen

1987-01-01

239

Hydraulic transients in transmission and distribution systems  

Microsoft Academic Search

Water hammer can degrade the integrity of a transmission or distribution system in one of two ways: through catastrophic failure or by benign failure. Catastrophic failure occurs during a water hammer event when pipes rupture, joints move, excessive noise occurs, etc. Benign failure may occur over a period of years and may consist of lining failure, pipe wall pitting, and

Allen Davis

2004-01-01

240

Authentication in distributed systems: a bibliography  

Microsoft Academic Search

Security of distributed systems is a topic of growing importance. The security breaches of the last few years (internet worm .... ) have demonstrated the need for additional research in this area. One important aspect of security is authentication. It is fundamental to access control, accounting and secure communication. This bibliography cont~s references of protocol descriptions and of protocol analysis

Armin Liebl

1993-01-01

241

Calcium dependence of open and shut interval distributions from calcium-activated potassium channels in cultured rat muscle.  

PubMed Central

The stochastic properties of single Ca-activated K channels in excised patches of surface membrane from cultured rat muscle cells were studied using the patch-clamp technique. The distribution of all open intervals was described by the sum of two exponential distributions of short and long mean open time, suggesting at least two major open-channel states. Increasing the concentration of Ca at the inner membrane surface, [Ca]i, increased the mean duration of the long open distribution, while having little effect on the mean duration of the short open distribution. The frequency of openings to each distribution increased with [Ca]i. The rate of increase was a much steeper function of [Ca]i for openings in the long open distribution than for openings in the short open distribution; about 80% of the openings were to the long open distribution with 0.1 microM-Cai, increasing to 97% with 1 microM-Cai (+ 30 mV). These results suggest that openings in both open distributions are Ca-dependent, with openings in the long open distribution requiring the binding of more Ca ions than openings in the short open distribution. The distribution of all shut intervals at 0.5 microM-Cai and + 30 mV was described by the sum of three exponential distributions with mean durations of: 0.21 msec (short shut distribution), 1.90 msec (intermediate shut), and 44 msec (long shut). These results indicate that the channel typically enters at least three closed channel states during normal channel activity. In addition, a few longer shut intervals not accounted for by the above distributions suggested that there was a fourth infrequently occurring inactivated closed-channel state. The mean duration of the distribution of long shut intervals decreased with a power of about 2 with increasing [Ca]i under conditions where most openings were to the long open state (+ 30 mV, 0.25-1 microM-Cai). This observation suggests that openings to the long open distribution typically require the binding of two or more Ca ions. The mean intermediate shut interval appeared to increase slightly with increasing [Ca]i while the mean short shut interval was relatively Cai-independent. The percentage of all shut intervals that were short shut intervals increased with increasing [Ca]i while the percentage of long shut intervals decreased.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:6317853

Magleby, K L; Pallotta, B S

1983-01-01

242

Use of open source distribution for a machine tool controller  

NASA Astrophysics Data System (ADS)

In recent years a growing number of government and university las, non-profit organizations and even a few for- profit corporations have found that making their source code public is good for both developers and users. In machine tool control, a growing number of users are demanding that the controllers they buy be `open architecture,' which would allow third parties and end-users at least limited ability to modify, extend or replace the components of that controller. This paper examines the advantages and dangers of going one step further, and providing `open source' controllers by relating the experiences of users and developers of the Enhanced Machine Controller. We also examine some implications for the development of standards for open-architecture but closed-source controllers. Some of the questions we hope to answer include: How can the quality be maintained after the source code has been modified? Can the code be trusted to run on expensive machines and parts, or when the safety of the operator is an issue? Can `open- architecture' but closed-source controllers ever achieve the level of flexibility or extensibility that open-source controllers can?

Shackleford, William P.; Proctor, Frederick M.

2001-02-01

243

Distributed System for Transfusion Supervision Based on Embedded System  

Microsoft Academic Search

In view of the shortcomings exist in current process of medical transfusion, a wireless distributed system for transfusion supervision was designed with infrared detection technology, computer network technology, embedded system technology and wireless transmission technology. The system is a network which consisted of a host computer, transfusion monitors, and interconnection mechanisms between the host computer and monitors. Comprised by a

Fenge Bai; Lifeng Huo; Li Bai; Junying Wang

2008-01-01

244

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

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

245

Open Quantum Systems and Quantum Algorithms  

E-print Network

The model of open quantum systems is adopted to describe the non-local dynamical behaviour of qubits processed by entangling gates. The analysis gets to the conclusion that a distinction between evaluation steps and task-oriented computing steps is justified only within classical computation. In fact, the use of entangling gates permits to reduce two steps (evaluation and calculation) to a single computational one, and this determines an effective computational speed-up. The application of the open quantum systems model suggests that the reduction to one-computational step is strongly related to the existence of Universal Dynamical Maps describing the evolution of component systems of two-qubits gates. As the description in terms of Universal Dynamical Map is possible only in the presence of a separable initial state, it turns out that the internal reduced dynamics with respect to entangling gates is neither unitary nor Markovian. The fact imposes a holistic vision on the structure of the algorithm, where the entangling gates shall remain indivisible unities, or black boxes, in order to preserve computational speed as well as reversibility. This fact suggests to adopt a perspective on computation which is completely non-classical: the whole algorithm turns out not to be the sequence of its temporal parts.

Stefano Bonzio; Paola Verrucchi

2013-01-09

246

Variational functions in degenerate open quantum systems  

SciTech Connect

We have derived a Lyapunov functional for a degenerate open atomic system. This functional develops monotonically towards its stationary state. The open system is described by a Lindblad-type master equation. For the construction of the variational functional it is necessary that the Lindblad operator can be diagonalized. Since the generator of motion is non-Hermitian, diagonalization is, in general, only possible if the eigenvalues are nondegenerate. In this paper, we propose that in a physical system the biorthogonal eigenbasis of the Lindblad operator remains complete even when degeneracy is present. Thus diagonalization of the Lindblad operator, and consequently the construction of the variational functional, is still possible. We discuss the reasons and illustrate the theory of the variational functional for a driven {lambda}-type three-level atom with degenerate ground state. The degeneracy has interesting effects on the variational functional in the steady state with respect to its interpretation as an entropic quantity. In case of the driven three-level atom, the dark state turns out to be an isentropic state.

Jakob, Matthias; Stenholm, Stig [Laser Physics and Quantum Optics, Royal Institute of Technology (KTH), Alba Nova, Roslagstullsbacken 21, SE-10691 Stockholm (Sweden)

2004-04-01

247

Variational functions in degenerate open quantum systems  

NASA Astrophysics Data System (ADS)

We have derived a Lyapunov functional for a degenerate open atomic system. This functional develops monotonically towards its stationary state. The open system is described by a Lindblad-type master equation. For the construction of the variational functional it is necessary that the Lindblad operator can be diagonalized. Since the generator of motion is non-Hermitian, diagonalization is, in general, only possible if the eigenvalues are nondegenerate. In this paper, we propose that in a physical system the biorthogonal eigenbasis of the Lindblad operator remains complete even when degeneracy is present. Thus diagonalization of the Lindblad operator, and consequently the construction of the variational functional, is still possible. We discuss the reasons and illustrate the theory of the variational functional for a driven ? -type three-level atom with degenerate ground state. The degeneracy has interesting effects on the variational functional in the steady state with respect to its interpretation as an entropic quantity. In case of the driven three-level atom, the dark state turns out to be an isentropic state.

Jakob, Matthias; Stenholm, Stig

2004-04-01

248

Control landscapes for open system quantum operations  

NASA Astrophysics Data System (ADS)

The reliable realization of control operations is a key component of quantum information applications. In practice, meeting this goal is very demanding for open quantum systems. This paper investigates the landscape defined as the fidelity J between the desired and achieved quantum operations with an open system. The goal is to maximize J as a functional of the control variables. We specify the complete set of critical points of the landscape function in the so-called kinematic picture. An associated Hessian analysis of the landscape reveals that, upon the satisfaction of a particular controllability criterion, the critical topology is dependent on the particular environment, but no false traps (i.e. suboptimal solutions) exist. Thus, a gradient-type search algorithm should not be hindered in searching for the ultimate optimal solution with such controllable systems. Moreover, the maximal fidelity is proven to coincide with Uhlmann’s fidelity between the environmental initial states associated with the achieved and desired quantum operations, which provides a generalization of Uhlmann’s theorem in terms of Kraus maps.

Wu, Re-Bing; Rabitz, Herschel

2012-12-01

249

Globally optimal maneuver of distributed systems  

NASA Technical Reports Server (NTRS)

This paper examines the globally optimal maneuver of distributed systems undergoing large overall rigid-body motion and small relative elastic motion. Using floating coordinates the rigid-body motion and the elastic motion are decoupled thereby allowing the globally optimal maneuver problem to be separated into components associated with the rigid-body and elastic motions. The maneuvers are performed using distributed maneuvering forces based on modal measurements. The modal measurements are extracted from the physical measurements using modal filters. Rest-to-rest maneuvers of a uniform beam illustrate the decentralized nature of the globally optimal solutions.

Silverberg, Larry; Park, Sungtae

1989-01-01

250

Distributed computer controls for accelerator systems  

SciTech Connect

A distributed control system has been designed and installed at the Lawrence Livermore National Laboratory Multi-user Tandem Facility using an extremely modular approach in hardware and software. The two tiered, geographically organized design allowed total system implementation with four months with a computer and instrumentation cost of approximately $100K. Since the system structure is modular, application to a variety of facilities is possible. Such a system allows rethinking and operational style of the facilities, making possible highly reproducible and unattended operation. The impact of industry standards, i.e., UNIX, CAMAC, and IEEE-802.3, and the use of a graphics-oriented controls software suite allowed the efficient implementation of the system. The definition, design, implementation, operation and total system performance will be discussed. 3 refs.

Moore, T.L.

1988-09-01

251

Reliability evaluation of distribution systems containing renewable distributed generations  

NASA Astrophysics Data System (ADS)

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.

Alkuhayli, Abdulaziz Abddullah

252

A Cosimulation Framework for a Distributed System of Systems  

Microsoft Academic Search

In this paper, we present a simple but powerful solution to combine two different simulation environments - SystemC and OMNeT++ - enabling a cosimulation framework for modeling and simulating a distributed system of systems. It is therefore possible to utilize the strengths and preliminary work of OMNeT++ in the field of communication networks and SystemC in modeling hardware entities. We

Bernd Müller-rathgeber; Holm Rauchfuss

2008-01-01

253

A system for distributed intrusion detection  

SciTech Connect

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.

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

254

Part III: AFS - A Secure Distributed File System  

SciTech Connect

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.

Wachsmann, A.; /SLAC

2005-06-29

255

System Engineering Strategy for Distributed Multi-Purpose Simulation Architectures  

NASA Technical Reports Server (NTRS)

This paper describes the system engineering approach used to develop distributed multi-purpose simulations. The multi-purpose simulation architecture focuses on user needs, operations, flexibility, cost and maintenance. This approach was used to develop an International Space Station (ISS) simulator, which is called the International Space Station Integrated Simulation (ISIS)1. The ISIS runs unmodified ISS flight software, system models, and the astronaut command and control interface in an open system design that allows for rapid integration of multiple ISS models. The initial intent of ISIS was to provide a distributed system that allows access to ISS flight software and models for the creation, test, and validation of crew and ground controller procedures. This capability reduces the cost and scheduling issues associated with utilizing standalone simulators in fixed locations, and facilitates discovering unknowns and errors earlier in the development lifecycle. Since its inception, the flexible architecture of the ISIS has allowed its purpose to evolve to include ground operator system and display training, flight software modification testing, and as a realistic test bed for Exploration automation technology research and development.

Bhula, Dlilpkumar; Kurt, Cindy Marie; Luty, Roger

2007-01-01

256

A.: SDL Code Generation for Open Systems  

E-print Network

Abstract. SDL claims to be a language for the description of open systems, allowing the integration of other components into an SDL system and that of an SDL system as a mere component into a greater unit. Indeed, SDL provides the possibility for the interaction of a system with its environment. Signals can be exchanged with the environment and in addition the developer may hide arbitrary actions inside external procedures. Code generators are widely in use to produce runnable code from an SDL system description, decreasing faultiness and increasing flexibility. But changes in or changes of the communication protocol to the environment still force a code generator to be adapted, costing precious resources. This paper presents an automated code generation from SDL to C++, which enables the flexible connection of various communication protocols without changing the code generator or adding code manually. A runtime library contains all necessary means for communication to the environment, an approach which has been tested using CORBA and Web Services, but could be adapted easily to arbitrary protocols. Problems with the choice of appropriate encodings seem to be solved with the recommendation Z.104, which enables the specification of encodings already in the SDL-2000 system. All results presented in this paper base on the experience gained in practice during several projects using Cinderella SITE. 1

Joachim Fischer; Toby Neumann; Anders Olsen; Cinderella Aps

2005-01-01

257

Quantum Speed Limits in Open System Dynamics  

NASA Astrophysics Data System (ADS)

Bounds to the speed of evolution of a quantum system are of fundamental interest in quantum metrology, quantum chemical dynamics, and quantum computation. We derive a time-energy uncertainty relation for open quantum systems undergoing a general, completely positive, and trace preserving evolution which provides a bound to the quantum speed limit. When the evolution is of the Lindblad form, the bound is analogous to the Mandelstam-Tamm relation which applies in the unitary case, with the role of the Hamiltonian being played by the adjoint of the generator of the dynamical semigroup. The utility of the new bound is exemplified in different scenarios, ranging from the estimation of the passage time to the determination of precision limits for quantum metrology in the presence of dephasing noise.

del Campo, A.; Egusquiza, I. L.; Plenio, M. B.; Huelga, S. F.

2013-02-01

258

Distribution system reliability evaluation with fuzzy data  

SciTech Connect

In the standard reliability evaluation of distribution systems, the failure rates and repair rates of lines and transformers are assumed to be constants because of the exponential behavior of their up times and down times. However, one can compute the distribution system reliability indices (basic and performance) using a set of values (with a degree of uncertainty) for failure rates and outage time of lines and transformers as well as the number of customers connected to a load point. Using the fuzzy set theory, a membership function can be provided to represent the uncertainty in the input data. This would allow a more reasonable representation of reliability data and provide more flexibility into the design or expansion process of new facilities for electric utilities. The application of this method will be illustrated with an example.

Asgarpoor, S. [Univ. of Nebraska, Lincoln, NE (United States)

1996-11-01

259

A remote monitoring system for Open Ocean Aquaculture  

Microsoft Academic Search

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

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

2002-01-01

260

A distributed power generation communication system  

Microsoft Academic Search

A distributed power generation system (DPGS) consists of a number of small-scale power generation sources (SSPGS) that provide electric power at a site closer to the user than the central power generation station. Small-scale power generation technologies currently available include wind turbines, fuel cells, micro gas\\/diesel turbines, small hydro generators and photovoltaic panels. Currently, most SSPGSs are locally controlled and

Julian Meng

2003-01-01

261

Multidimensional Index on Hadoop Distributed File System  

Microsoft Academic Search

In this paper, we present an approach to construct a built-in block-based hierarchical index structures, like R-tree, to organize data sets in one, two, or higher dimensional space and improve the query performance towards the common query types (e.g., point query, range query) on Hadoop distributed file system (HDFS). The query response time for data sets that are stored in

Haojun Liao; Jizhong Han; Jinyun Fang

2010-01-01

262

Distributed simulation for power system analysis including shipboard systems  

Microsoft Academic Search

Power systems are distributed in nature. Often they can be divided into sections or groups and treated separately. Terrestrial power systems are divided into separate utilities and are controlled by different regional transmission organization (RTO). Each RTO has detailed data for the area under its control, but only limited data and boundary measurements of the external network. Additionally, shipboard power

Jian Wu; Noel N. Schulz; Wenzhong Gao

2007-01-01

263

System level concurrency control for distributed database systems  

Microsoft Academic Search

A distributed database system is one in which the database is spread among several sites and application programs “move” from site to site to access and update the data they need. The concurrency control is that portion of the system that responds to the read and write requests of the application programs. Its job is to maintain the global consistency

Daniel J. Rosenkrantz; Richard Edwin Stearns; Philip M. Lewis II

1978-01-01

264

COMMUNICATION SYSTEMS AND STUDY METHOD FOR ACTIVE DISTRIBUTION POWER SYSTEMS  

E-print Network

of Intelligent Electronic Devices (IED) in modern distributed power system need to exchange large amount of information for system monitoring, protection and control. Therefore the alternative communication techniques toward Smart Grid, which means an electricity network that can intelligently integrate the actions of all

Chen, Zhe

265

Electric power distribution and load transfer system  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

266

Disinfection of water distribution systems for Legionella.  

PubMed

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

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

1998-06-01

267

Open Systems Dynamics for Propagating Quantum Fields  

E-print Network

In this dissertation, I explore interactions between matter and propagating light. The electromagnetic field is modeled as a 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. Within the framework of open quantum systems, the light is eventually traced out, leaving the reduced quantum state of the system as the primary mathematical subject. Two major results are presented. The first is a master equation approach for a quantum system interacting with a traveling wave packet prepared with a definite number of photons. In contrast to quasi-classical states, such as coherent or thermal fields, these N-photon states possess temporal mode entanglement, and local interactions in time have nonlocal consequences. The second is a model for a three-dimensional light-matter interface for an atomic ensemble interacting with a paraxial laser beam and its application to the generation of QND spin squeezing. Both coherent and incoherent dynamics due to spatially inhomogeneous atom-light coupling across the ensemble are accounted for. Measurement of paraxially scattered light can generate squeezing of an atomic spin wave, while diffusely scattered photons lead to spatially local decoherence.

Ben Q. Baragiola

2014-08-18

268

Smart Operations in Distributed Energy Resources System  

NASA Astrophysics Data System (ADS)

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

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

269

Integrated, multivendor distributed data-acquisition system  

SciTech Connect

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.

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

1988-08-01

270

KeyWare: an open wireless distributed computing environment  

Microsoft Academic Search

Deployment of distributed applications in the wireless domain lack equivalent tools, methodologies, architectures, and network management that exist in LAN based applications. A wireless distributed computing environment (KeyWareTM) based on intelligent agents within a multiple client multiple server scheme was developed to resolve this problem. KeyWare renders concurrent application services to wireline and wireless client nodes encapsulated in multiple paradigms

Isaac Shpantzer; Larry Schoenfeld; Merv Grindahl; Vladimir Kelman

1995-01-01

271

Open Source Course Management Systems: A Case Study  

ERIC Educational Resources Information Center

In Fall 2003, Randolph-Macon Woman's College rolled out Claroline, an Open Source course management system for all the classes on campus. This document will cover some background on both Open Source in general and course management systems in specific, discuss technical challenges in the introduction and integration of the system and give some…

Remy, Eric

2005-01-01

272

Quantum response of dephasing open systems  

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

273

Tools for Continuously Evaluating Distributed System Qualities James H. Hill  

E-print Network

with system execution modeling tools--can enable agile development of distributed systems and facili- tate the software lifecycle. Keywords. agile techniques, continuous system inte- gration, distributed systemsTools for Continuously Evaluating Distributed System Qualities James H. Hill Indiana University

Schmidt, Douglas C.

274

On-Site Wastewater Treatment Systems: Subsurface Drip Distribution  

E-print Network

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...

Lesikar, Bruce J.

1999-09-06

275

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

E-print Network

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....

Lesikar, Bruce J.; Enciso, Juan

1999-08-12

276

Open-cycle MHD systems analysis  

NASA Astrophysics Data System (ADS)

Five variant configurations of a coal burning open cycle magnetohydrodynamic electric power generating facility were studied for evaluation as candidate first generation power plants. A material and energy balance and cycle analysis was performed for each case to provide information for the conceptual designs and costing of all major MHD related components and subsystems as well as specification of other state of the art components. A economic comparison was made of each design by developing the cost of electricity based on component costs, estimates of operation and maintenance requirements, and the performance of each plant from the system analyses. An overall description of each plant is provided along with discussions of critical component and process development. An oxygen enriched OCMHD plant design was identified as an attractive candidate for first generation utility service. This plant design appears to offer competitive costs of electricity and minimizes development risk.

Lippert, T. E.; Weeks, K. D.

1980-02-01

277

Random Control over Quantum Open Systems  

E-print Network

Parametric fluctuations or stochastic signals are introduced into the control pulse sequence to investigate the feasibility of random control over quantum open systems. In a large parameter error region, the out-of-order control pulses work as well as the regular pulses for dynamical decoupling and dissipation suppression. Calculations and analysis are based on a non-perturbative control approach allowed by an exact quantum-state-diffusion equation. When the average frequency and duration of the pulse sequence take proper values, the random control sequence is robust, fault- tolerant, and insensitive to pulse strength deviations and interpulse temporal separation in the quasi-periodic sequence. This relaxes the operational requirements placed on quantum control experiments to a great deal.

Jun Jing; C. Allen Bishop; Lian-Ao Wu

2014-07-03

278

Scalable open architecture project (SOAP) avionics evolution from Federated to Open Systems  

Microsoft Academic Search

The Scalable Open Architecture Project (SOAP) of NAVAIR's Maritime Avionics Subsystems and Technologies (MAST) Program was established in 1996 to demonstrate how to evolve existing aircraft from federated to advanced scalable open systems through incremental system upgrades making maximum use of COTS technology. This project is a multiyear effort with a series of laboratory demonstrations that transform existing federated avionics

J. Ozols

1997-01-01

279

Building a generalized distributed system model  

NASA Technical Reports Server (NTRS)

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.

Mukkamala, R.

1993-01-01

280

Distributed-aperture infrared sensor systems  

NASA Astrophysics Data System (ADS)

The on-going maturation of electro-optic technology in which the advent of third generation focal plane array is being combined with the capabilities of increasingly powerful signal processing algorithm now points to a new direction in design of electro-optic sensor system for both military and non-military applications. Taking advantage of those advances. Distributed Aperture IR Sensor systems (DAIRS) are currently in development within the Defense Department for installation in a variety of platforms for utilization in a wide variety of tactical scenarios. DAIRS employs multiple fixed identical sensor to obtain the functionality that was previously obtained using specialized sensors for each function. In its role in tactical scenarios. DAIRS employs multiple fixed identical sensor to obtain the functionality that was previously obtained using specialized sensor for each function. In its role in tactical aircraft, DAIRS uses an array of six strategically located sensors which provide 4(pi) steradian sensor coverage, i.e., full sphere situational awareness (SA), to the aircrew. That awareness provides: missile threat warning, IR Search and Track, battle damage assessment, targeting assistance, and pilotage. DAIRS has applicability in providing expanded SA for surface ships, armored land vehicles and unmanned air combat vehicles. A typical sensor design has less than twenty-five percent of the weight, volume, and electrical power demand of current federated airborne IR sensor system and can become operational with a significant reduction in lifetime system cost. DAIRS, when combined with autocueing, may have a significant role in technological advancement of aircraft proximity warning system for in-flight collision avoidance. DAIRS is currently founded in part by the Office of Naval Research which will result in the IR Distributed Aperture System (MIDAS), which is funded as a Navy Advanced Technology Demonstration, the DAIRS will undergo airborne testing using four sensor in FY-00. MIDAS will include integration of a helmet mounted display for situational awareness imaging.

Brusgard, Thomas C.

1999-07-01

281

Design leadership for a distribution management system architecture  

SciTech Connect

Distribution Automation (DA) as a concept has existed for more than a decade. However, it has only been recently through technological advancements and pilot projects by pioneering utilities that it has become an economic practicality. A number of leading utilities have contributed to the evolution of this technology. The performance goals to be achieved in implementing DA technology have been evolved through previous DA projects and have been established for ongoing projects. These goals establish a clear focus for defining implementation plans for DA technology and include the following: (1) Reduced Customer Outages; (2) Commercial Customer Retention Constant Voltage Regulation; (3) Capital Expenditure Reductions; and (4) Personnel Productivity. In the past decade, many Utilities have initiated a number of pilot projects, each designed to improve some aspect of the company`s service to its customers. Each of these projects will impact the way the distribution system is operated and introduce new technology that must be mastered. Without a coordinated effort, these systems will be implemented in scattered locations using equipment, software, communication interfaces, and user interfaces that differ for each application. The distribution dispatchers would be required to interact with each of these {open_quotes}islands of automation{close_quotes} separately, resulting in an increased level of complexity and an increase in the burden of their duties. A Distribution Management System (DMS) architecture is needed to provide the infrastructure for coordinated implementation of DA technology. Using this broad company-wide model for automation, each pilot project can be viewed as part of a broader set of functions that will be supported by the DMS.

Green, T.A.

1994-12-31

282

Epidemiology of urban water distribution systems  

NASA Astrophysics Data System (ADS)

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.

Bardet, Jean-Pierre; Little, Richard

2014-08-01

283

An open source laboratory for operating systems projects  

Microsoft Academic Search

Typical undergraduate operating systems projects use services provided by an operating system via system calls or develop code in a simulated operating system. With the increasing popularity of operating systems with open source code such as Linux, there are untapped possibilities for operating systems projects to modify real operating system code. We present the hardware and software configuration of an

Mark Claypool; David Finkel; Craig E. Wills

2001-01-01

284

Inelastically scattering particles and wealth distribution in an open economy  

NASA Astrophysics Data System (ADS)

Using the analogy with inelastic granular gases we introduce a model for wealth exchange in society. The dynamics is governed by a kinetic equation, which allows for self-similar solutions. The scaling function has a power-law tail, the exponent being given by a transcendental equation. In the limit of continuous trading, a closed form of the wealth distribution is calculated analytically.

Slanina, František

2004-04-01

285

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

E-print Network

"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" ...

Boudreau, Kevin J. (Kevin Joseph)

2006-01-01

286

The physics of distributed information systems  

NASA Astrophysics Data System (ADS)

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

Aurell, Erik

2013-12-01

287

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

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

288

Analysis and control of distributed cooperative systems.  

SciTech Connect

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.

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

2004-09-01

289

Scattering properties of periodically-driven open quantum systems  

Microsoft Academic Search

In this dissertation we elucidate some of the mechanisms underlying the decay and scattering properties of periodically-driven open quantum systems. First, using a complex spectral decomposition we study some of the mechanisms underlying the decay processes in weakly-driven open quantum systems. A complex spectral decomposition involves generalized eigenstates associated with complex poles of the analytically continued energy Green's function. These

Agapi Emmanouilidou

2002-01-01

290

Skeletal anchorage system for open-bite correction  

Microsoft Academic Search

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

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

1999-01-01

291

Cave Fauna Distribution within Fully-Flooded Cave Systems in Florida  

Microsoft Academic Search

Because organisms living in Florida's fully-flooded caves depend upon allochthonous input for food, abundances of cave fauna may be related to distance from cave openings. Distributions of cave crayfish and catfish were investigated within 16 fully-flooded cave systems. In each cave, a transect was established beginning at the edge of the aphotic zone and continuing into the cave for 244

J. A. Hale; W. J. Streever

1994-01-01

292

Toward Data Confidentiality via Integrating Hybrid Encryption Schemes and Hadoop Distributed File System  

Microsoft Academic Search

With the increasing popularity of cloud computing, Hadoop has become a widely used open source cloud computing framework for large scale data processing. However, few studies have been done to enhance data confidentiality of Hadoop against storage servers. In this paper, we address the data confidentiality issue by integrating hybrid encryption schemes and the Hadoop distributed file system (HDFS). We

Hsiao-Ying Lin; Shiuan-Tzuo Shen; Wen-Guey Tzeng; Bao-Shuh P. Lin

2012-01-01

293

Cross Entropy multiobjective optimization for water distribution systems design  

Microsoft Academic Search

A methodology extending the Cross Entropy combinatorial optimization method originating from an adaptive algorithm for rare events simulation estimation, to multiobjective optimization of water distribution systems design is developed and demonstrated. The single objective optimal design problem of a water distribution system is commonly to find the water distribution system component characteristics that minimize the system capital and operational costs

Lina Perelman; Avi Ostfeld; Elad Salomons

2008-01-01

294

Analyzing the Redesign of a Distributed Lift System in UPPAAL  

E-print Network

Analyzing the Redesign of a Distributed Lift System in UPPAAL Jun Pang1 , Bart Karstens1 and Wana, 1081 HV Amsterdam, The Netherlands, wanf@cs.vu.nl Abstract. An existing distributed lift system by analyzing the redesign of a distributed lift system. This lift system is used in real life for lifting

Fokkink, Wan

295

Distributed fiber optic moisture intrusion sensing system  

DOEpatents

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.

Weiss, Jonathan D. (Albuquerque, NM)

2003-06-24

296

Fuzzy expert system for distribution system restoration and contingency operation  

SciTech Connect

Over the years, computer technologies have been applied to operate the distribution system in the most reliable and efficient manner. In this work, a fuzzy expert system prototype had been developed to aid operators in distribution system restoration and contingency operation. The knowledge base, which contains the different strategies used in the project, had been adopted from the standard operating procedures of the Manila Electric Company (MERALCO). For restoration planning, the following factors were utilized in the evaluation of the solutions: percent load of the circuit and transformer and percent unbalance of the circuit. On the other hand, circuit overloads, transformer overloads and bus voltage correction had been addressed in contingency operation. Fuzzy logic membership functions were employed to compromise among conflicting evaluation factors. A Newton-Raphson loadflow was integrated into the system to verify the soundness of the solutions in case of doubt. The prototype was tested on a portion of MERALCO`s distribution network which consists of 12 distribution substations with 25 buses and 24 lines. Within its problem domain, the prototype performed as expected.

Mendiola, M.C.; Chang, C.S.; Elangovan, S. [National Univ. of Singapore (Singapore). Dept. of Electrical Engineering

1995-12-31

297

Open quantum systems and error correction  

NASA Astrophysics Data System (ADS)

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.

Shabani Barzegar, Alireza

298

Differential Distributions of Synechococcus Subgroups Across the California Current System  

PubMed Central

Synechococcus is an abundant marine cyanobacterial genus composed of different populations that vary physiologically. Synechococcus narB gene sequences (encoding for nitrate reductase in cyanobacteria) obtained previously from isolates and the environment (e.g., North Pacific Gyre Station ALOHA, Hawaii or Monterey Bay, CA, USA) were used to develop quantitative PCR (qPCR) assays. These qPCR assays were used to quantify populations from specific narB phylogenetic clades across the California Current System (CCS), a region composed of dynamic zones between a coastal-upwelling zone and the oligotrophic Pacific Ocean. Targeted populations (narB subgroups) had different biogeographic patterns across the CCS, which appear to be driven by environmental conditions. Subgroups C_C1, D_C1, and D_C2 were abundant in coastal-upwelling to coastal-transition zone waters with relatively high to intermediate ammonium, nitrate, and chl. a concentrations. Subgroups A_C1 and F_C1 were most abundant in coastal-transition zone waters with intermediate nutrient concentrations. E_O1 and G_O1 were most abundant at different depths of oligotrophic open-ocean waters (either in the upper mixed layer or just below). E_O1, A_C1, and F_C1 distributions differed from other narB subgroups and likely possess unique ecologies enabling them to be most abundant in waters between coastal and open-ocean waters. Different CCS zones possessed distinct Synechococcus communities. Core California current water possessed low numbers of narB subgroups relative to counted Synechococcus cells, and coastal-transition waters contained high abundances of Synechococcus cells and total number of narB subgroups. The presented biogeographic data provides insight on the distributions and ecologies of Synechococcus present in an eastern boundary current system. PMID:21833315

Paerl, Ryan W.; Johnson, Kenneth S.; Welsh, Rory M.; Worden, Alexandra Z.; Chavez, Francisco P.; Zehr, Jonathan P.

2011-01-01

299

Transparent access to distributed, heterogeneous environmental information systems  

SciTech Connect

Quality situation assessment and decision making require access to multiple sources of data and information. The question facing today`s analyst is not so much {open_quotes}Is the data I need to do my work available?{close_quotes} as {open_quotes}How can I get to the data I need to make an informed decision?{close_quotes} Insufficient accessibility to data exists for many large corporations and Government agencies. By utilizing current advances in computer technology, today`s situation analysts have a wealth of information at their disposal. There are many potential solutions to the information accessibility problem using today`s technology. The United States Department of Energy (US-DOE) faced this situation when dealing with the problem of high level radioactive waste (HLW) tanks in the United States. The result of their efforts has been the creation of the Tank Waste Information Network System -- TWINS. The TWINS solution combines many technologies to address problems in several areas such as user interfaces, transparent access to multiple data sources, and integrated data access. Data related to the HLW tank complex is currently distributed throughout several US-DOE installations. Over time, each installation has adopted its own set of standards for information management, hardware, and software platforms. These factors contribute to the complexity of accessing information in a manner that enhances the performance and decision making process of the analysts. This paper presents one approach taken by the US-DOE to resolve the problem of distributed, heterogeneous, multi-media information management through the development of multilevel architectural controls and access mechanisms for the HLW Tank complex. The information system architecture developed for the US-DOE by the TWINS effort is one that is adaptable to other problem domains and uses.

Brown, J.C.; Kissinger, B.A.

1994-09-01

300

Importance of Hydrogeological Conditions on Open-loop Geothermal System  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

301

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

Microsoft Academic Search

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

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

1990-01-01

302

Distributed computer system enhances productivity for SRB joint optimization  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

303

Adaptive, Distributed Control of Constrained Multi-Agent Systems  

Microsoft Academic Search

Product Distribution (PD) theory was recently developed as a framework for analyzing and optimizing distributed systems. In this paper we demonstrate its use for adaptive distributed control of Multi-Agent Systems (MASýs), i.e., for distributed stochastic optimization using MASýs. One common way to perform the optimization is to have each agent run a Reinforcement Learning (RL) algorithm. PD theory provides an

Stefan Bieniawski; David H. Wolpert

2004-01-01

304

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

E-print Network

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...

Lesikar, Bruce J.; Enciso, Juan

1999-08-12

305

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

E-print Network

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

British Columbia, University of

306

Requirements specification of distributed hard real-time operating systems  

Microsoft Academic Search

The authors present the requirements specification for distributed hard real-time operating systems used in time-critical, mission-oriented systems. For this purpose the relevant models for distributed hard real-time processing are established based on the general characteristics of distributed hard real-time systems. Following these models the requirements of a distributed hard real-time operating system are specified, and the major concerns in requirements

ManSang Chung; Heonshik Shin

1991-01-01

307

Energy Efficiency of Distributed Environmental Control Systems  

SciTech Connect

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

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

2011-02-23

308

Multiple weapon system distributed sensor concept  

NASA Astrophysics Data System (ADS)

Distributed Sensor Concept-DISCO was proposed for multiplication of individual weapon capability through cooperative target engagement. DISCO creates practically distributed in space sensor network that performs sensing by exchanging of pre-track frame and GNC data. Concept of operations for DISCO is based on complete absence of any kind of host vehicle with its weight allocated for unique and costly propulsion, communication and avionics, and, in the same time DISCO preserves the original idea of multiplicity of lightweight effective weapon dispensed from an unitary payload Three major benefits of DISCO are: immediate PBO deployment; absence of any kind of carrier or "central" vehicle or bus; multiplicity of weapon. DISCO sensor network supports target handover without active ranging but by triangulating. Digital video-signal processing that supports DISCO is Recursive Adaptive Frame Integration of Limited data. Each sensor disseminates to and receives frame, calibration and GNC data from other sensors in the network. In this paper efficiency of DISCO weapon system is discussed for acquisition, accurate handover and track correlation.

Rafailov, Michael K.

2009-05-01

309

Open MPI for Cray XE/XK Systems  

SciTech Connect

Open MPI provides an implementation of the MPI standard supporting communications over a range of high-performance network interfaces. Recently, ORNL and LANL have collaborated on creating a port of Open MPI for Gemini, the network interface for Cray XE and XK systems. In this paper, we present our design and implementation of Open MPI's point-to-point and collective operations for Gemini, and techniques we employ to provide good scaling, and performance characteristics.

Gorentla Venkata, Manjunath [ORNL; Graham, Richard L [ORNL; Hjelm, Nathan T [Los Alamos National Laboratory (LANL); Gutierrez, Samuel K [Los Alamos National Laboratory (LANL)

2012-01-01

310

Developing an Information Systems Infrastructure with Open Source Software  

Microsoft Academic Search

Up to now, most open source software deployments have been in invisible infrastructure applications running on back-office servers (GNU\\/Linux, Apache, and so on). Beaumont Hospital in Ireland recently started developing its overall information systems infrastructure by deploying more visible desktop and front-office open source applications in addition to GNU\\/Linux and Apache. In a two-phase open source implementation, Beaumont will save

Brian Fitzgerald; Tony Kenny

2004-01-01

311

The Production and Distribution of Knowledge through Open and Distance Learning  

Microsoft Academic Search

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

Stephen Fox

1989-01-01

312

Quantum key distribution system clocked at 2 GHz  

E-print Network

Quantum key distribution system clocked at 2 GHz Karen J. Gordon, Veronica Fernandez, Gerald S-based quantum key distribution test system performance in terms of transmission distance and quantum bit error. Zbinden, "Quantum key distribution over 67 km with a plug & play system," New J. Phys. 4, 41.1-41.8 (2002

Buller, Gerald S.

313

Fractional System Identification: An Approach Using Continuous Order-Distributions  

NASA Technical Reports Server (NTRS)

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.

Hartley, Tom T.; Lorenzo, Carl F.

1999-01-01

314

HPC: A Model of Structure and Change in Distributed Systems  

Microsoft Academic Search

Distributed systems must provide certain fundamental facilities including communication. protection. resource management, reliability. and process (computation) abstraction. Current designs for distributed systems tend to focus on only one of these issues; support for multiprocess structures has been especially neglected. The HPC model, an object-oriented model of interprocess relationships for distributed systems. addresses all of these fundamental services. The major novelties

Thomas J. Leblanc; Stuart A. Friedberg

1985-01-01

315

Services Supporting Management of Distributed Applications and Systems  

Microsoft Academic Search

A distributed computing system consists of heterogeneous computing devices, communicationnetworks, operating system services and applications. As organisations movetoward distributed computing environments, there will be a corresponding growth in distributedapplications central to the enterprise.The design, development, and management of distributed applications presents manydifficult challenges. As these systems grow to hundreds or even thousands of devices andsimilar or greater...

Michael A. Bauer; Richard B. Bunt; Asham El Rayess; Patrick J. Finnigan; Thomas Kunz; Hanan Lutfiyya; Andrew D. Marshall; Patrick Martin; Gregory M. Oster; Wendy Powley; Jerome A. Rolia; David J. Taylor; C. Murray Woodside

1997-01-01

316

Model reference active optimal distributed tracking system for the linear distributed parameter systems  

Microsoft Academic Search

This paper presents a technique for designing an active optimal tracking system for control of a linear distributed parameter process for applications where precise tracking of the commanded trajectories or a reference model is required. Its dynamic performance is quite satisfactory where the boundary conditions are either unpredictable or the primary cause of the instability. The type of processes considered

Allen Moshfegh

1994-01-01

317

ARCHITECTURES FOR DISTRIBUTED PROCESSING: THE NEXT GENERATION OF OPEN GIS  

Microsoft Academic Search

Geographical Information Systems (GIS) have the necessary functionality for the manipulation of spatial data, allowing u sers to collect, manage and analyze large volumes of spatially associated and referenced data. In the past, GISs used p roprietary, closed d ata structures, adapted to support specific data types, like maps or satellite images. More recently, facilities for database management, such as

Celso Roberto Perez; Carlos André; Guimarães Ferraz; Ana Carolina Salgado

318

FOR DISTRIBUTED PROCESSING: THE NEXT GENERATION OF OPEN GIS  

Microsoft Academic Search

Geographical Information Systems (GIS) have the necessary functionality for the manipulation of spatial data, allowing u sers to collect, manage and analyze large volumes of spatially associated and referenced data. In the past, GISs used p roprietary, closed d ata structures, adapted to support specific data types, like maps or satellite images. More recently, facilities for database management, such as

Celso Roberto Perez; Carlos André; Guimarães Ferraz; Ana Carolina Salgado

319

6.824 Distributed Computer Systems, Fall 2002  

E-print Network

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 ...

Morris, Robert Tappan

320

An Operator-Based Exact Treatment of Open Quantum Systems  

E-print Network

"Quantum mechanics must be regarded as open systems. On one hand, this is due to the fact that, like in classical physics, any realistic system is subjected to a coupling to an uncontrollable environment which influences it in a non-negligible way. The theory of open quantum systems thus plays a major role in many applications of quantum physics since perfect isolation of quantum system is not possible and since a complete microscopic description or control of the environment degrees of freedom is not feasible or only partially so" [1]. Practical considerations therefore force one to seek for a simpler, effectively probabilistic description in terms of an open system. There is a close physical and mathematical connection between the evolution of an open system, the state changes induced by quantum measurements, and the classical notion of a stochastic process. The paper provides a bibliographic review of this interrelations, it shows the mathematical equivalence between markovian master equation and generaliz...

Nicolosi, S

2005-01-01

321

Systems coordinating distributed collaborative work must manage user data distributed over a network. The strong con-  

E-print Network

1 Abstract Systems coordinating distributed collaborative work must manage user data distributed: Distributed Data Management Collaborative applications coordinate activities which may be distributed in time. This paper considers strategies which can be employed to meet the conflicting demands placed on collaborative

Dourish,Paul

322

Role a development system plays in electrical distribution automation experiments  

SciTech Connect

A software development and testing system is being used to support the operation and experimental utilization of a large-scale electrical distribution automation system. The testing system provides the mechanisms to simulate the characteristics of both the large-scale control system and the electrical distribution system that is being controlled.

Wetherington, G.R. Jr.; Broadaway, E.R.; Bentz, R.R.

1986-01-01

323

ModelBased Diagnosis for Open Systems Fault Management  

E-print Network

, and correction of faults remains intractable. Fault management is there- fore a prominent functional area of open1 Model­Based Diagnosis for Open Systems Fault Management F. Steimann, P. Fr¨ohlich and W. Nejdl for model­based diagnosis. Based thereon, we present an efficient algorithm that localizes faults

Steimann, Friedrich

324

Open Source Library Management Systems: A Multidimensional Evaluation  

ERIC Educational Resources Information Center

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…

Balnaves, Edmund

2008-01-01

325

Free and Open Systems Theory Nick Rossiter  

E-print Network

a concept of freeness and openness such as life, consciousness and intelli- gence, biology and medicine [Klir 1993], quantum phe- nomena in nanotechnology, etc. The large global sys- tems needing much

Cheng, Eugenia

326

Distributed fiber optic fuel leak detection system  

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

327

Distributed fiber optic fuel leak detection system  

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

328

Characterizing and Improving Distributed Intrusion Detection Systems.  

SciTech Connect

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.

Hurd, Steven A.; Proebstel, Elliot P.

2007-11-01

329

Complex network analysis of water distribution systems  

E-print Network

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 towards 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 non-heterogeneous 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.

A. Yazdani; P. Jeffrey

2011-04-01

330

Control of the quantum open system via quantum generalized measurement  

SciTech Connect

For any specified pure state of quantum open system, we can construct a kind of quantum generalized measurement (QGM) that the state of the system after measurement will be deterministically collapsed into the specified pure state from any initial state. In other words, any pure state of quantum open system is reachable by QGM. Subsequently, whether the qubit is density matrix controllable is discussed in the case of pure dephasing. Our results reveal that combining QGM with coherent control will enhance the ability of controlling the quantum open system. Furthermore, it is found that the ability to perform QGM on the quantum open system, combined with the ability of coherence control and conditions of decoherence-free subspace, allows us to suppress quantum decoherence.

Zhang Ming; Zhu Xiaocai; Li Xingwei; Hu Dewen [College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China); Dai Hongyi [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China)

2006-03-15

331

DisTec: Towards a Distributed System for Telecom Computing  

NASA Astrophysics Data System (ADS)

The continued exponential growth in both the volume and the complexity of information, compared with the computing capacity of the silicon-based devices restricted by Moore's Law, is giving birth to a new challenge to the specific requirements of analysts, researchers and intelligence providers. With respect to this challenge, a new class of techniques and computing platforms, such as Map-Reduce model, which mainly focus on scalability and parallelism, has been emerging. In this paper, to move the scientific prototype forward to practice, we elaborate a prototype of our applied distributed system, DisTec, for knowledge discovery from social network perspective in the field of telecommunications. The major infrastructure is constructed on Hadoop, an open-source counterpart of Google's Map-Reduce. We carefully devised our system to undertake the mining tasks in terabytes call records. To illustrate its functionality, DisTec is applied to real-world large-scale telecom dataset. The experiments range from initial raw data preprocessing to final knowledge extraction. We demonstrate that our system has a good performance in such cloud-scale data computing.

Yang, Shengqi; Wang, Bai; Zhao, Haizhou; Gao, Yuan; Wu, Bin

332

Open cycle ocean thermal energy conversion system  

DOEpatents

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.

Wittig, J. Michael (West Goshen, PA)

1980-01-01

333

DESIGN ASPECTS OF COMMERCIAL OPEN-LOOP HEAT PUMP SYSTEMS  

Microsoft Academic Search

Open loop (or groundwater heat pump systems are the oldest of the ground-source systems. Common design variations include direct (groundwater used directly in the heat pump units), indirect (building loop isolated with a plate heat exchanger), and standing column (water produced and returned to the same well). Direct systems are typically limited to the smallest applications. Standing column systems are

KEVIN RAFFERTY

2001-01-01

334

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

Microsoft Academic Search

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

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

1990-01-01

335

Robustness Reducing Model of Distributed Artificial Immune System  

Microsoft Academic Search

With the model of reducing robustness for the distributed multi-agent system, the robustness analysis problem of the distributed artificial immune system (DAIS) was reduced into robustness analysis problems of all the independent modules of the system. The artificial immune system (AIS) included the module of modeling the normal model, the module of detecting selfs and non-selfs, the module of recognizing

Tao Gong; Zixing Cai

2007-01-01

336

A high performance and low cost distributed file system  

Microsoft Academic Search

Recently, the concept of distributed file system has been widely used in many Internet applications. A distributed file system integrates many file servers on the network and becomes an efficiency file system with large storage space. Users can access their files anytime and anywhere. However, the cost for building and maintaining these storage systems is high for many small enterprises

Tzong-Jye Liu; Chun-Yan Chung; Chia-Lin Lee

2011-01-01

337

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

SciTech Connect

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.

Hammerstrom, Donald J.

2007-06-28

338

The changing face of technology in distributed systems  

Microsoft Academic Search

Discusses some distribution support aspects, which are the structuring principles and the technologies that will change, or that are already changing, the face of distributed systems, and investigates how to take advantage of them. In particular, I examine internetworking and interprocess communication, the basis for the formation of large-scale distributed systems. I also discuss how multipoint communication, logical addressing, membership

Paulo Verissimo; Werner Vogels

1993-01-01

339

A Distributed Logic for Networked Cyber-Physical Systems  

E-print Network

by existing distributed computing paradigms. They must be reactive and maintain an overall situation awareness that emerges from partial distributed knowledge. They must achieve system goals through local, asynchronousA Distributed Logic for Networked Cyber-Physical Systems Minyoung Kim, Mark-Oliver Stehr

Venkatasubramanian, Nalini

340

Modeling of heterotrophic bacteria counts in a water distribution system  

Microsoft Academic Search

Heterotrophic plate count (HPC) constitutes a common indicator for monitoring of microbiological water quality in distribution systems (DS). This paper aims to identify factors explaining the spatiotemporal distribution of heterotrophic bacteria and model their occurrence in the distribution system. The case under study is the DS of Quebec City, Canada. The study is based on a robust database resulting from

Alex Francisque; Manuel J. Rodriguez; Luis F. Miranda-Moreno; Rehan Sadiq; François Proulx

2009-01-01

341

Distributed Directory Service in the Farsite File System  

Microsoft Academic Search

We present the design, implementation, and evaluation of a fully distributed directory service for Farsite, a logically centralized file system that is physically implemented on a loosely coupled network of desktop computers. Prior to this work, the Farsite system included distributed mechanisms for file content but centralized mechanisms for file metadata. Our distributed directory service introduces tree-structured file identifiers that

John R. Douceur; Jon Howell

2006-01-01

342

An Operator-Based Exact Treatment of Open Quantum Systems  

E-print Network

"Quantum mechanics must be regarded as open systems. On one hand, this is due to the fact that, like in classical physics, any realistic system is subjected to a coupling to an uncontrollable environment which influences it in a non-negligible way. The theory of open quantum systems thus plays a major role in many applications of quantum physics since perfect isolation of quantum system is not possible and since a complete microscopic description or control of the environment degrees of freedom is not feasible or only partially so" [1]. Practical considerations therefore force one to seek for a simpler, effectively probabilistic description in terms of an open system. There is a close physical and mathematical connection between the evolution of an open system, the state changes induced by quantum measurements, and the classical notion of a stochastic process. The paper provides a bibliographic review of this interrelations, it shows the mathematical equivalence between markovian master equation and generalized piecewise deterministic processes [1] and it introduces the open system in an open observed environment model.

S. Nicolosi

2005-04-04

343

Assessment of distributed photovoltair electric-power systems  

NASA Astrophysics Data System (ADS)

The development of a methodology to assess the potential impacts of distributed photovoltaic (PV) systems on electric utility systems, including subtransmission and distribution networks, and to apply that methodology to several illustrative examples was developed. The investigations focused upon five specific utilities. Impacts upon utility system operations and generation mix were assessed using accepted utility planning methods in combination with models that simulate PV system performance and life cycle economics. Impacts on the utility subtransmission and distribution systems were also investigated. The economic potential of distributed PV systems was investigated for ownership by the utility as well as by the individual utility customer.

Neal, R. W.; Deduck, P. F.; Marshall, R. N.

1982-10-01

344

An Open-Systems Approach to Teaching Family Therapy.  

ERIC Educational Resources Information Center

Describes an attempt to facilitate a consistently open-systems approach which stimulates rapid growth, learning, and group cohesiveness. Presented at the Annual Conference of the American Association of Marital and Family Therapists in Houston, October 1978. (Author/BEF)

Skynner, A. C. Robin; Skynner, Prudence M.

1979-01-01

345

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

E-print Network

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

Bowker, Geoffrey C.

346

An open-systems approach to video on demand  

Microsoft Academic Search

Open systems will enable video servers and set-tops to provide different services in a variety of environments. Hewlett-Packard is interested in applying the principles of open systems to video on demand (VOD). In particular, the company is developing a technology base that will allow their servers and set-tops to operate in a variety of environments and enable the provision of

Yee-Hsiang Chang; David Coggins; D. Pitt; David Skellern; Manu Thapar; Chandra Venkatraman

1994-01-01

347

Distributed Gradient Systems and Dynamic Coordination Demetri P. Spanos  

E-print Network

Distributed Gradient Systems and Dynamic Coordination Thesis by Demetri P. Spanos In Partial: A Distributed Averaging Protocol . . . . . . . . . . . . . . . . . . . . . 16 3 Dynamic Coordination: Principles . . . . . . . . . . . . . . 30 3.2.1 Interactions and Coordinations . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3

Murray, Richard M.

348

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

349

DSC: a system for distributed symbolic computation  

Microsoft Academic Search

DSC is a general purpose tool that allows the distribution of a computation over a network of Unix workstations. Its control mechanisms automatically start up daemon processes on the participating workstations in order to communicate data by the standard IP\\/TCP\\/UDIP protocols. The user's program distributes either remote procedure calls or source code of programs and their corresponding input data files

A. Diaz; Erich Kaltofen; K. Schmitz; T. Valente

1991-01-01

350

ROLF--An Open Learning Delivery System.  

ERIC Educational Resources Information Center

Discusses the Resourced Open Learning Facility (ROLF), which was developed by the U.K. Skills Training Agency (STA) as a means of delivering off-the-job skill training for the unemployed. Employment training is discussed and an evaluation of ROLF is described, including management issues and types of trainees. (Author/LRW)

Twining, John; And Others

1989-01-01

351

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

NASA Astrophysics Data System (ADS)

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.

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

2010-08-01

352

The Imagery Exchange (TIE): Open Source Imagery Management System  

NASA Astrophysics Data System (ADS)

The NASA's Global Imagery Browse Service (GIBS) is the Earth Observation System (EOS) imagery solution for delivering global, full-resolution satellite imagery in a highly responsive manner. GIBS consists of two major subsystems, OnEarth and The Imagery Exchange (TIE). TIE is the GIBS horizontally scaled imagery workflow manager component, an Open Archival Information System (OAIS) responsible for orchestrating the acquisition, preparation, generation, and archiving of imagery to be served by OnEarth. TIE is an extension of the Data Management and Archive System (DMAS), a high performance data management system developed at the Jet Propulsion Laboratory by leveraging open source tools and frameworks, which includes Groovy/Grails, Restlet, Apache ZooKeeper, Apache Solr, and other open source solutions. This presentation focuses on the application of Open Source technologies in developing a horizontally scaled data system like DMAS and TIE. As part of our commitment in contributing back to the open source community, TIE is in the process of being open sourced. This presentation will also cover our current effort in getting TIE in to the hands of the community from which we benefited from.

Alarcon, C.; Huang, T.; Thompson, C. K.; Roberts, J. T.; Hall, J. R.; Cechini, M.; Schmaltz, J. E.; McGann, J. M.; Boller, R. A.; Murphy, K. J.; Bingham, A. W.

2013-12-01

353

24 CFR 3280.609 - Water distribution systems.  

...2014-04-01 2014-04-01 false Water distribution systems. 3280.609 Section...STANDARDS Plumbing Systems § 3280.609 Water distribution systems. Link to an amendment...78 FR 73986, Dec. 9, 2013. (a) Water supply —(1) Supply piping....

2014-04-01

354

DISTRIBUTED COMPUTING SYSTEMS LABORATORY SCHOOL OF COMPUTER SCIENCE AND ENGINEERING  

E-print Network

DISTRIBUTED COMPUTING SYSTEMS LABORATORY SCHOOL OF COMPUTER SCIENCE AND ENGINEERING SEOUL NATIONAL://dcslab.snu.ac.kr/projects/mpichgf Heon Y. Yeom Namyoon Woo & Hyungsoo Jung Distributed Computing Systems Laboratory School of Computer SYSTEMS LABORATORY SCHOOL OF COMPUTER SCIENCE AND ENGINEERING SEOUL NATIONAL UNIVERSITY Introduction

Yeom, Heon Young

355

Conflicts in Policy-Based Distributed Systems Management  

Microsoft Academic Search

Modern distributed systems contain a large number of objects, and must be capable of evolving, without shutting down the complete system, to cater for changing requirements. There is a need for distributed, automated management agents whose behavior also has to dynamically change to reflect the evolution of the system being managed. Policies are a means of specifying and influencing management

Emil C. Lupu; Morris Sloman

1999-01-01

356

Flight plan management in a distributed air traffic control system  

Microsoft Academic Search

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

P. Queinnec; Gdrard Padiou

1993-01-01

357

Disquisition of Shooting Information Distribution System based on AJAX  

Microsoft Academic Search

According to the bussiness requirement of Shooting Information Distribution Systems (IDS) based on sufficient investigation, the development status of similar system and relatived technology at home and abroad are analysed and studied in this paper. The bussiness workflow is analysed deeply based on the example of shooting results inquiry. Then a solution is proposed for Information Distribution System by remote

Chen Peng; Luan Yinxia

2010-01-01

358

1 Research Group on Computer Networks and Distributed Systems  

E-print Network

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

Sola, Rolf Haenni

359

Collaborative Creativity: A Complex Systems Model with Distributed Affect  

E-print Network

that a dynamical systems approach similar to that used to understand the spread of innovative technologies is a new dynamical systems model of creativity in distributed groups that includes affect as wellCollaborative Creativity: A Complex Systems Model with Distributed Affect Cecilia R. Aragon

Anderson, Richard

360

Guest Editorial: Special Section on Security in Distributed Computing Systems  

Microsoft Academic Search

has always been of utmost importance, particularly in recent years as orchestrated attacks have sought to cripple critical infrastructures. Security issues in distributed com-puting systems involve reducing vulnerabilities as well as giving system management the insight and control needed to defend distributed information systems. All aspects of business and government operations and services are dependent upon the security and integrity

Wei Zhao

2003-01-01

361

Trends in multiprocessor and distributed operating systems designs  

Microsoft Academic Search

This paper presents an overview of the developments in operating systems technology for distributed computing systems and multiprocessor machines. We focus on those design principles that are now widely accepted as useful design paradigms. Approaches common to distributed and multiprocessor operating systems are identified. Issues discussed include process scheduling and synchronization, load balancing, virtual and shared-memory management and parallel file

Anand R. Tripathi; Neeran M. Karnik

1995-01-01

362

Computational methods for the control of distributed parameter systems  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

363

Influence of Subsea Cables on Offshore Power Distribution Systems  

Microsoft Academic Search

Subsea cable applications for the offshore power distribution systems create technical challenges in the system design, operation and maintenance. Harmonic parallel resonance introduced by subsea cables is one of the main concerns. In this paper, parallel resonance is investigated for an offshore distribution system with lengthy subsea cables on four interconnected platforms. Variable frequency drives are the dominant loads on

Xiaodong Liang; William Jackson

2008-01-01

364

Influence of Subsea Cables on Offshore Power Distribution Systems  

Microsoft Academic Search

Subsea cable applications for the offshore power distribution systems create technical challenges in the system design, operation, and maintenance. Harmonic parallel resonance introduced by subsea cables is one of the main concerns. In this paper, parallel resonance is investigated for an offshore distribution system with lengthy subsea cables on four interconnected platforms. Variable frequency drives (VFDs) are the dominant loads

Xiaodong Liang; William Michael Jackson

2009-01-01

365

An Open Simulation System Model for scientific applications  

NASA Technical Reports Server (NTRS)

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.

Williams, Anthony D.

1995-01-01

366

An Open Simulation System Model for Scientific Applications  

NASA Technical Reports Server (NTRS)

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.

Williams, Anthony D.

1995-01-01

367

Realizing Distributed TTCN-3 Test Systems with TCI  

Microsoft Academic Search

Distributed test setups for efficient load, performance, scalability, interworking, and end-to-end tests are gaining importance for the assessment of distributed communicating systems. The Testing and Test Control Notation TTCN-3 provides concepts for component-based distributed test systems in dynamic test configurations, where test components may reside on various network nodes to be near the interfaces of the tested system. The realization

Ina Schieferdecker; Theofanis Vassiliou-gioles

2003-01-01

368

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...

369

Transperitoneal view of the PROLENE hernia system open mesh repair.  

PubMed

The PROLENE Hernia System (PHS), consisting of an onlay and an underlay patch with a connector, has recently been introduced as an option for tension-free open repair of inguinal hernias and is touted for the repair of both direct and indirect hernias. In theory, the underlay is placed either through the internal ring or through the transversalis fascia and is seated in the preperitoneal space. To date, there have been no views of how this underlay is seated after open repair. Our objective was to determine the position and orientation of the underlay patch after open repair. After informed consent, two patients requiring both umbilical and inguinal hernia repairs had their inguinal hernias repaired using the open technique with the PHS. In the first patient, after open inguinal repair, the umbilical hernia was reduced, a 30 degrees laparoscope was placed intraperitoneally, and the underlay patch placed in the retroperitoneal space was visualized through the translucent peritoneum. In the second patient, the umbilical hernia was initially reduced, and the laparoscope was introduced to visualize the creation of the preperitoneal space and placement of the underlay during open repair of the inguinal hernia. As per our hypothesis, we show that the preperitoneal space is successfully created during open repair with the PHS with minimal trauma. More importantly, the underlay is deployed open and contours to the shape of the abdominal wall from the native intra-abdominal pressure, covering regions at risk for future herniation. PMID:16463951

Awad, Samir S; Bruckner, Brian; Fagan, Shawn P

2005-01-01

370

Can High-Performance Interconnects Benefit Hadoop Distributed File System? Sayantan Sur, Hao Wang, Jian Huang, Xiangyong Ouyang and Dhabaleswar K. Panda  

E-print Network

Can High-Performance Interconnects Benefit Hadoop Distributed File System? Sayantan Sur, Hao Wang and has been adopted by many organizations. The Hadoop Distributed File System (HDFS) lies at the heart, HDFS has also become the underlying file system for the Hadoop database (HBase), that is an Open

Panda, Dhabaleswar K.

371

Conventions spreading in open-ended systems  

NASA Astrophysics Data System (ADS)

We introduce a simple open-ended model that describes the emergence of a shared vocabulary. The ordering transition toward consensus is generated only by an agreement mechanism. This interaction defines a finite and small number of states, despite each individual having the ability to invent an unlimited number of new words. The existence of a phase transition is studied by analyzing the convergence times, the cognitive efforts of the agents and the scaling behavior in memory and time.

Brigatti, E.; Roditi, I.

2009-02-01

372

Distributed Impact Detector System (DIDS) Health Monitoring System Evaluation  

NASA Technical Reports Server (NTRS)

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.

Prosser, William H.; Madaras, Eric I.

2010-01-01

373

Spin density distribution in open-shell transition metal systems: A comparative post-Hartree-Fock, Density Functional Theory and quantum Monte Carlo study of the CuCl2 molecule  

E-print Network

We present a comparative study of the spatial distribution of the spin density (SD) of the ground state of CuCl2 using Density Functional Theory (DFT), quantum Monte Carlo (QMC), and post-Hartree-Fock wavefunction theory (WFT). A number of studies have shown that an accurate description of the electronic structure of the lowest-lying states of this molecule is particularly challenging due to the interplay between the strong dynamical correlation effects in the 3d shell of the copper atom and the delocalization of the 3d hole over the chlorine atoms. It is shown here that qualitatively different results for SD are obtained from these various quantum-chemical approaches. At the DFT level, the spin density distribution is directly related to the amount of Hartree-Fock exchange introduced in hybrid functionals. At the QMC level, Fixed-node Diffusion Monte Carlo (FN-DMC) results for SD are strongly dependent on the nodal structure of the trial wavefunction employed (here, Hartree-Fock or Kohn-Sham with a particula...

Caffarel, Michel; Scemama, Anthony; Ramírez-Solís, Alejandro

2014-01-01

374

Distributed Information System for Dynamic Ocean Data in Indonesia  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

375

Gluing for Dynamic Simulation of Distributed Mechanical Systems  

Microsoft Academic Search

A new concept of gluing, also known as co-simulation, for dynamic simulation of distributed mechanical systems is presented to couple subsystem models in a distributed computing environment. Using the new gluing algorithm, subsystem models can be analyzed at their distributed locations, using their own independent solvers, and on their own platforms. The gluing algorithm relies only on information available at

Gregory M. Hulbert; Zheng-Dong Ma; Jinzhong Wang

376

Full-chip verification methods for DSM power distribution systems  

Microsoft Academic Search

Power distribution verification is rapidly becoming a necessary step in deep submicron (DSM) design of high performance integrated circuits. With the increased load and reduced tolerances of DSM circuits, more failures are being seen due to poorly designed power distribution systems. This paper describes an efficient approach for the verification of power distribution at the full-chip transistor level based on

Gregory Steele; David Overhauser; Steffen Rochel; Syed Zakir Hussain

1998-01-01

377

Ceph: A Scalable, High-Performance Distributed File System  

Microsoft Academic Search

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,

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

2006-01-01

378

Distributed Diagnosis of Dynamic Systems Using Dynamic Bayesian Networks  

E-print Network

Distributed Diagnosis of Dynamic Systems Using Dynamic Bayesian Networks Indranil Roychoudhury.koutsoukos}@vanderbilt.edu Abstract: This paper presents a Dynamic Bayesian Network (DBN)-based distributed diagnosis scheme, where each distributed diagnoser generates globally correct diagnosis results without a centralized

Koutsoukos, Xenofon D.

379

Architectural Design of Adaptive Distributed Multimedia Systems  

E-print Network

Institute for Telecommunications Research (CITR)1, we have developed a prototype system for remote access to News-on-Demand. This system allows the user to remotely access a multimedia database, containing news multimedia system for remote access to multimedia databases. This design focuses on the aspects of the system

von Bochmann, Gregor

380

Non-equilibrium thermodynamics approach to open quantum systems  

E-print Network

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 of dynamical and thermodynamical properties of open quantum systems. The power of the approach is illustrated with the application to the damped harmonic oscillator and the damped driven two-level system resulting in analytical expressions for the non-Markovian and non-equilibrium entropy and inverse temperature.

Vitalii Semin; Francesco Petruccione

2014-10-23

381

Comments on open-ended magnetic systems for fusion  

SciTech Connect

Differentiating characteristics of magnetic confinement systems having externally generated magnetic fields that are open'' are listed and discussed in the light of their several potential advantages for fusion power systems. It is pointed out that at this stage of fusion research high-Q'' (as deduced from long energy confinement times) is not necessarily the most relevant criterion by which to judge the potential of alternate fusion approaches for the economic generation of fusion power. An example is given of a hypothetical open-geometry fusion power system where low-Q operation is essential to meeting one of its main objectives (low neutron power flux).

Post, R.F.

1990-09-24

382

OOONEIDA: an open, object-oriented knowledge economy for intelligent distributed automation  

Microsoft Academic Search

OOONEIDA is a new initiative for enabling decentralized, agile industrial control and automation in discrete manufacturing and continuous process systems. The goal of the OOONEIDA project is the creation of the technological infrastructure for a new, open knowledge economy for automation components and automated industrial products. This will be done by further development of the concept of reusable portable software

Valeriy Vyatkin; J. Christensen; J. L. M. Lastra; F. Auinger

2003-01-01

383

Greenstone: a comprehensive open-source digital library software system  

Microsoft Academic Search

This paper describes the Greenstone digital library software, a comprehensive, open-source system for the construction and presentation of information collections. Collections built with Greenstone offer effective full-text searching and metadata-based browsing facilities that are attractive and easy to use. Moreover, they are easily maintainable and can be augmented and rebuilt entirely automatically. The system is extensible: software \\

Ian H. Witten; Stefan J. Boddie; David Bainbridge; Rodger J. McNab

2000-01-01

384

Greenstone: A Comprehensive Open-Source Digital Library Software System  

Microsoft Academic Search

This paper describes the Greenstone digital library software, a comprehensive, open-source system for the construction and presentation of information collections. Collections built with Greenstone offer effective full-text searching and metadata-based browsing facilities that are attractive and easy to use. Moreover, they are easily maintainable and can be augmented and rebuilt entirely automatically. The system is extensible: software \\

Ian H. Witten; Rodger J. McNab; Stefan J. Boddie; David Bainbridge

1999-01-01

385

Quantum Games in Open Systems using Biophysic Hamiltonians  

E-print Network

We analyze the necessary physical conditions to model an open quantum system as a quantum game. By applying the formalism of Quantum Operations on a particular system, we use Kraus operators as quantum strategies. The physical interpretation is a conflict among different configurations of the environment. The resolution of the conflict displays regimes of minimum loss of information.

Jean Faber; Renato Portugal; Luiz Pinguelli Rosa

2006-06-26

386

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

ERIC Educational Resources Information Center

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

Gleason, Bernard W.

387

POSTER PRESENTATION Open Access Dynamics of neural systems in epilepsy  

E-print Network

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

Paris-Sud XI, Université de

388

GamingAnywhere--The First Open Source Cloud Gaming System  

E-print Network

believe, will stimulate more research innovations on cloud gaming systems and applications. Categories: Design, Measurement Additional Key Words and Phrases: Cloud games, remote rendering, live video streaming1 GamingAnywhere--The First Open Source Cloud Gaming System CHUN-YING HUANG, National Taiwan Ocean

Chen, Sheng-Wei

389

Integrating security in a large distributed system  

Microsoft Academic Search

Andrew is a distributed computing environment that is a synthesis of the personal computing and timesharing paradigms. When mature, it is expected to encompass over 5,000 workstations spanning the Carnegie Mellon University campus. This paper examines the security issues that arise in such an environment and describes the mechanisms that have been developed to address them. These mechanisms include the

Mahadev Satyanarayanan

1989-01-01

390

Component Interaction in Concurrent and Distributed Systems  

Microsoft Academic Search

Modern distributed programming environments commonly restrict programmers to a single form of intercomponent interaction. This forces programmers to emulate other interaction styles in terms of the dominant paradigm, obscuring their intent and resulting in a loss of clarity. Starting from a clear model of interaction between program components, this paper attempts to restore this missing clarity of intent. It achieves

Nat Pryce

1998-01-01

391

Managing Distributed Systems with Smart Subscriptions  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

392

Quantum key distribution systems and field trials  

Microsoft Academic Search

Recent progress in quantum key distribution (QKD), regarding high-speed and long-distance experiments and field trials are briefly reviewed. We also introduce our research on the randomness of quantum key. We have confirmed a quantum key, as a crypto key, assures the required randomness with some dynamic compensation.

A. Tanaka; M. Fujiwara; Sae Woo Nam; Y. Nambu; S. Takahashi; W. Maeda; K.-I. Yoshino; S. Miki; Burm Baek; Zhen Wang; A. Tajima; M. Sasaki; A. Tomita

2008-01-01

393

Concurrency Control in Distributed Database Systems  

Microsoft Academic Search

In this paper we survey, consolidate, and present the state of the art in distributed database concurrency control. The heart of our analysts is a decomposition of the concurrency control problem into two major subproblems: read-write and write-write synchronization. We describe a series of synchromzation techniques for solving each subproblem and show how to combine these techniques into algorithms for

Philip A. Bernstein; Nathan Goodman

1981-01-01

394

DECALS: distributed experiment control and logging system  

Microsoft Academic Search

In developing distributed applications and services there is a need to be able to set up and run tests on a set of processes. The experiment might be to obtain performance data, to test the processes' behaviour, or to evaluate an application management strategy. Common requirements are • to load and run special versions of at least some of the

Alex Hubbard; C. Murray Woodside; Cheryl Schramm

1995-01-01

395

Spherical stellar systems with spheroidal velocity distributions  

Microsoft Academic Search

Families of anisotropic distribution functions that are consistent with any spherically symmetric density profile are derived by means of a method employing an algorithm which is sufficiently straightforward for the derivation of analytic solutions. Each solution is defined by a single, free, 'anisotropy radius' parameter. The models are isotropic in the center, and become either radially or tangentially anisotropic at

D. Merritt

1985-01-01

396

ESTIMATING COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS  

EPA Science Inventory

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

397

The Topaz System: Distributed Multiprocessor Personal Computing  

Microsoft Academic Search

this paper, we give a brief overview of Topaz, andthen make some observations based on our use of the systemand our plans for the future. These observations fall into twoareas: our experience with multiprocessing in a workstation,and our views on distribution and autonomy.2 Topaz overview

Paul McJones; Andy Hisgen

1987-01-01

398

Numerical Analysis of a Cold Air Distribution System  

E-print Network

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...

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

2006-01-01

399

Distributed Space System Technology Demonstrations with the Emerald Nanosatellite  

NASA Technical Reports Server (NTRS)

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.

Twiggs, Robert

2002-01-01

400

Fuzzy logic based operated device identification in power distribution systems  

E-print Network

Fault location in distribution systems is a challenging task because of the lack of homogeneity in the system and due to uncertainity in the data used for estimating the faulted sections. Fuzzy logic has widely been applied for handling...

Manivannan, Karthick Muthu

2012-06-07

401

3.3 Gigahertz Clocked Quantum Key Distribution System  

Microsoft Academic Search

A fibre-based quantum key distribution system operating up to a clock frequency of 3.3GHz is presented. The system demonstrates significantly increased key exchange rate potential and operates at a wavelength of 850nm.

Karen J. Gordon; Veronica Fernandez; Robert J. Collins; Ivan Rech; Sergio D. Cova; Paul D. Townsend; Gerald S. Buller

2006-01-01

402

3.3 Gigahertz Clocked Quantum Key Distribution System  

E-print Network

A fibre-based quantum key distribution system operating up to a clock frequency of 3.3GHz is presented. The system demonstrates significantly increased key exchange rate potential and operates at a wavelength of 850nm.

Karen J. Gordon; Veronica Fernandez; Robert J. Collins; Ivan Rech; Sergio D. Cova; Paul D. Townsend; Gerald S. Buller

2006-05-05

403

A New Power Flow Method in Radial Distribution Systems  

NASA Astrophysics Data System (ADS)

In this paper, a new efficient method is proposed for power flow calculation in radial distribution systems. The distribution busines is changing the need to plan and respond to technical change, growth in distributed generation and deregulated power markets. Thus, it is important to improve fundamental analytical tools in distribution systems. This paper proposes a new method for the power flow calculation in distribution systems. The Newton-Raphson method does not work in some distribution systems. As a result, DistFlow that focuses on the network topology was developed to overcome the problem. However, there is still room for improvement in terms of computational efficiency. In this paper, a method is proposed to improve the efficiency in creating the Jacobian.

Ohyoshi, Wataru; Mori, Hiroyuki

404

Nonlinear semiclassical dynamics of open systems.  

PubMed

A semiclassical approximation for an evolving density operator, driven by a 'closed' Hamiltonian and 'open' Markovian Lindblad operators, is reviewed. The theory is based on the chord function, i.e. the Fourier transform of the Wigner function. It reduces to an exact solution of the Lindblad master equation if the Hamiltonian is a quadratic function and the Lindblad operators are linear functions of positions and momenta. The semiclassical formulae are interpreted within a (real) double phase space, generated by an appropriate classical double Hamiltonian. An extra 'open' term in the double Hamiltonian is generated by the non-Hermitian part of the Lindblad operators in the general case of dissipative Markovian evolution. Decoherence narrows the relevant region of double phase space to the neighbourhood of a caustic for both the Wigner function and the chord function. This difficulty is avoided by the definition of a propagator, here developed in both representations. Generalized asymptotic equilibrium solutions are thus presented for the first time. PMID:21149370

Ozorio de Almeida, A M; Brodier, O

2011-01-28

405

Distributed Energy System Validation, Commissioning and  

E-print Network

................................................................................................................... 4 2.2 Sunny Boy PV Inverter System................................................................................ 9 3.1 PV System to Sunny Boy Inverter............................................................................ 9 3.2 Sunny Boy Inverter to PV Sub

406

Underground distribution cable incipient fault diagnosis system  

E-print Network

This dissertation presents a methodology for an efficient, non-destructive, and online incipient fault diagnosis system (IFDS) to detect underground cable incipient faults before they become catastrophic. The system provides vital information...

Jaafari Mousavi, Mir Rasoul

2007-04-25

407

An analysis of distributed solar fuel systems  

E-print Network

While solar fuel systems offer tremendous potential to address global clean energy needs, most existing analyses have focused on the feasibility of large centralized systems and applications. Not much research exists on ...

Thomas, Alex, S.M. Massachusetts Institute of Technology

2012-01-01

408

Distributed naming in a factored operating system  

E-print Network

A factored operating system (fos) is a new operating system design for manycore and cloud computers. In fos, OS services are separated from application code and run on distinct cores. Furthermore, each service is split ...

Beckmann, Nathan (Nathan Zachary)

2010-01-01

409

A model system for examining the radial distribution function  

NSDL National Science Digital Library

The radial distribution function is a measure of the spatial distribution of a system of particles. The authors discuss an experiment suitable for undergraduates that illustrates the meaning of the radial distribution function for a two-dimensional system of hard spheres comprised of varying area fractions. Larger area fractions lead to an increase in the correlation length and the magnitude of the underlying particleâparticle correlations.

Younge, K.; Christenson, C.; Bohara, A.; Crnkovic, J.; Saulnier, Paul

2011-07-02

410

DSF: A Common Platform for Distributed Systems Research and Development  

Microsoft Academic Search

This paper presents Distributed Systems Foundation (DSF), a common platform for distributed systems research and development.\\u000a It can run a distributed algorithm written in Java under multiple execution modes—simulation, massive multi-tenancy, and real\\u000a deployment. DSF provides a set of novel features to facilitate testing and debugging, including chaotic timing test and time\\u000a travel debugging with mutable replay. Unlike existing research

Chunqiang Tang

2009-01-01

411

Dynamic Computation Migration in Distributed Shared Memory Systems  

E-print Network

Dynamic Computation Migration in Distributed Shared Memory Systems by Wilson Cheng-Yi Hsieh S Computation Migration in Distributed Shared Memory Systems by Wilson Cheng-Yi Hsieh Submitted of the requirements for the degree of Doctor of Philosophy in Computer Science Abstract Computation migration is a new

Gummadi, Ramakrishna

412

Separating Data and Control Transfer in Distributed Operating Systems  

E-print Network

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 A increased reliability, when compared to current LANs such as Ethernet. We believe that these new network

Thekkath, Chandramohan A.

413

File Replication and Distribution System for Low Bandwidth Networks  

Microsoft Academic Search

In this paper, we introduce DISTREP, a multiplatform and operating system independent file distribution and replication package. It features dynamic distribution and low-overhead network connections that efficiently conserve network bandwidth. A complete replication to M machines of N bytes in DISTREP may only require a transfer of at least N bytes, less than the NM bytes that other systems require.

Daniel G. Pamintuan II; Eliezer A. Albacea

2002-01-01

414

A review of integrated analysis of production–distribution systems  

Microsoft Academic Search

This paper reviews recent work on integrated analysis of production–distribution systems, and identifies important areas where further research is needed. By integrated analysis we understand analysis performed on models that integrate decisions of different production and distribution functions for a simultaneous optimization. We review work that explicitly considers the transportation system in the analysis, since we are interested in the

Ana Maria Sarmiento; Rakesh Nagi

1999-01-01

415

Delft University of Technology Parallel and Distributed Systems Report Series  

E-print Network

, wildlife habitat monitoring, climate control, and disaster management. The underlying technologyDelft University of Technology Parallel and Distributed Systems Report Series Distributed of Information Technology and Systems Delft University of Technology, The Netherlands koen@pds.twi.tudelft.nl N

Langendoen, Koen

416

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...

417

Stability of phase-modulated quantum key distribution systems  

Microsoft Academic Search

The stability of double Mach-Zehnder implementation has been investigated in experiment, which is important for practical quantum key distribution systems. The results of experiment show that the random fluctuation of interference visibility comes from polarization disturbance, especially from that of transmission fiber. A theoretical model is built and a necessary condition is given for intrinsic-stabilization unidirectional quantum key distribution system.

Zheng-Fu Han; Xiao-Fan Mo; You-Zhen Gui; Guang-Can Guo

2005-01-01

418

Quantum key distribution system clocked at 2 GHz  

Microsoft Academic Search

An improved quantum key distribution test system operating at clock rates of up to 2GHz using a specially adapted commercially-available silicon single-photon counting module is presented. The use of an enhanced detector has improved the fiber-based quantum key distribution test system performance in terms of transmission distance and quantum bit error rate.

Karen J. Gordon; Veronica Fernandez; Gerald S. Buller; Ivan Rech; Sergio D. Cova; Paul D. Townsend

2005-01-01

419

Optimal static load balancing in distributed computer systems  

Microsoft Academic Search

A distributed computer system that consists of a set of heterogeneous host computers connected in an arbitrary fashion by a communications network is considered. A general model is developed for such a distributed computer system, in which the host computers and the communications network are represented by product-form queuing networks. In this model, a job may be either processed at

Asser N. Tantawi; Donald F. Towsley

1985-01-01

420

Modeling the Delivery Physiology of Distributed Learning Systems.  

ERIC Educational Resources Information Center

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

Paquette, Gilbert; Rosca, Ioan

2003-01-01

421

Graffiti: A Framework for Testing Collaborative Distributed File System  

E-print Network

Graffiti: A Framework for Testing Collaborative Distributed File System Metadata C. MALTZAHN metadata for online content [21] we present Graffiti, a distributed organization layer for collaboratively sharing rich metadata across heterogeneous file systems. The primary purpose of Graffiti is to provide

Maltzahn, Carlos

422

Logging and Recovery in Adaptive Software Distributed Shared Memory Systems  

Microsoft Academic Search

Software distributed shared memory (DSM) improves the programmability of message-passing machines and work- station clusters by providing a shared memory abstract (i.e., a coherent global address space) to programmers. As in any distributed system, however, the probability of software DSM failures increases as the system size grows. This pa- per presents a new, efficient logging protocol for adaptive software DSM

Angkul Kongmunvattana; Nian-feng Tzeng

1999-01-01

423

Holistic schedulability analysis for distributed hard real-time systems  

Microsoft Academic Search

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

Ken Tindell; John Clark

1994-01-01

424

A Taxonomy and Survey on Distributed File Systems  

Microsoft Academic Search

Applications that process large volumes of data (such as, search engines, grid computing applications, data mining applications, etc.) require a backend infrastructure for storing data. The distributed file system is the central component for storing data infrastructure. There have been many projects focused on network computing that have designed and implemented distributed file systems with a variety of architectures and

Doan Thanh Tran; Subaji Mohan; Eunmi Choi; SangBum Kim; Pilsung Kim

2008-01-01

425

An Overview of Checkpointing in Uniprocessor and Distributed Systems,  

E-print Network

An Overview of Checkpointing in Uniprocessor and Distributed Systems, Focusing on Implementation of Tennessee July, 1997 1 #12; An Overview of Checkpointing in Uniprocessor and Distributed Systems, Focusing://www.cs.utk.edu/~plank/plank/papers/Wiley.html for complete publishing information concerning this paper. Abstract Checkpointing is the act of saving

Plank, Jim

426

Analysis Model for Domestic Hot Water Distribution Systems: Preprint  

SciTech Connect

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.

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

2011-11-01

427

Introduction to a system for distributed databases (SDD1)  

Microsoft Academic Search

The declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. SDD-1 is a distributed database management system currently being developed by Computer Corporation of America. Users interact with SDD-1 precisely as if it were a nondistributed database system because SDD-1 handles all issues arising from

James B. Rothnie Jr.; Philip A. Bernstein; Stephen Fox; Nathan Goodman; Michael Hammer; T. A. Landers; Christopher L. Reeve; David W. Shipman; Eugene Wong

1980-01-01

428

Analysis of multi-stage open shop processing systems  

E-print Network

We study algorithmic problems in multi-stage open shop processing systems that are centered around reachability and deadlock detection questions. We characterize safe and unsafe system states. We show that it is easy to recognize system states that can be reached from the initial state (where the system is empty), but that in general it is hard to decide whether one given system state is reachable from another given system state. We show that the problem of identifying reachable deadlock states is hard in general open shop systems, but is easy in the special case where no job needs processing on more than two machines (by linear programming and matching theory), and in the special case where all machines have capacity one (by graph-theoretic arguments).

Eggermont, Christian; Woeginger, Gerhard J

2011-01-01

429

FIPA agent based network distributed control system  

SciTech Connect

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

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

2003-03-01

430

Lessons learned in transitioning to an open systems environment  

NASA Technical Reports Server (NTRS)

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).

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

1994-01-01

431

Arbitrarily accurate dynamical control in open quantum systems.  

PubMed

We show that open-loop dynamical control techniques may be used to synthesize unitary transformations in open quantum systems in such a way that decoherence is perturbatively compensated for to a desired (in principle arbitrarily high) level of accuracy, which depends only on the strength of the relevant errors and the achievable rate of control modulation. Our constructive and fully analytical solution employs concatenated dynamically corrected gates, and is applicable independently of detailed knowledge of the system-environment interactions and environment dynamics. Explicit implications for boosting quantum gate fidelities in realistic scenarios are addressed. PMID:20366973

Khodjasteh, Kaveh; Lidar, Daniel A; Viola, Lorenza

2010-03-01

432

Effect of particle distribution on electrostatic tomography system  

NASA Astrophysics Data System (ADS)

Particle is charged due to frictional contact and collisions between particles and pipe wall. Electrostatic tomography technology (EST) is used to monitor the traveling particle charge. However the electric field distribution in the electrostatic sensor arrays is simultaneously affected by both the particle permittivity distribution and particle charge. In the paper, the effect of the different particle flow regimes on EST is investigated numerically and experimentally. Results indicated the particle distribution affected the induced charge on the electrostatic sensor array. But the effect relates to the relationship between the charge distribution and the particle distribution. Furthermore, a fusion of dual modality tomography system consisting of a capacitance sensor and electrostatic sensor arrays is used to investigate the relationship between the particle distribution and charge distribution in a gravity conveying rig. Results showed that the higher particle concentration has higher charge distribution in the gravity conveying rig. Additionally, the measurement of the mass flow rate by EST was investigated.

Gao, Heming; Xu, Chuanlong; Fu, Feifei; Wang, Shimin

2012-03-01

433

DETERIORATION OF DRINKING WATER DISTRIBUTION SYSTEMS  

EPA Science Inventory

A frequently overlooked fact, but one that is becoming of increasing concern, is the effect that the drinking water delivery system can have on the quality of water received at the tap. Deterioration of aging water supply systems can result in pipeline failures, pressure losses, ...

434

Transient Analysis of Water Distribution Systems  

Microsoft Academic Search

The pressures generated by transient (water hammer) conditions in pipe systems are frequently three or more times the value of normal operating pressures. Thus, transient pressures must be known if the size and strength of the required pipe is to be rationally selected, if surge-suppression equipment is to be logically sized, and if system operating rules are to be intelligently

Bryan W. Karney; Duncan McInnis

1990-01-01

435

Interfaces for Distributed Systems of Information Servers.  

ERIC Educational Resources Information Center

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

Kahle, Brewster; And Others

1992-01-01

436

Quantum key distribution system for metropolitan-area networks  

Microsoft Academic Search

Requirements and specifications of quantum key distribution (QKD) systems are examined particularly for metropolitanarea networks. A design of QKD system is considered to satisfy the specifications. BB84 protocol with decoy method is chosen. The unidirectional system based on planer light wave circuit for high speed operation is proposed for quantum transmission. Issues on system control such as clock synchronization and

A. Tomita

2007-01-01

437

Federated database systems for managing distributed, heterogeneous, and autonomous databases  

Microsoft Academic Search

A federated database system (FDBS) is a collection of cooperating database systems that are autonomous and possibly heterogeneous. In this paper, we define a reference architecture for distributed database management systems from system and schema viewpoints and show how various FDBS architectures can be developed. We then define a methodology for developing one of the popular architectures of an FDBS.

Amit P. Sheth; James A. Larson

1990-01-01

438

Spearmints: hardware support for performance measurements in distributed systems  

Microsoft Academic Search

Spearmints, a system of hardware components that can be easily interfaced to the nodes of an instrumented distributed system for monitoring or evaluation using event-triggered measurements, is described. Each machine of the target system must have one sensor that collects relevant events and marks them with global time stamps. The sensors can be attached to a common measurement system that

Uwe Kleinhans; Joerg Kaiser; Karol Czaja

1993-01-01

439

Distributed video game streaming system for pervasive gaming  

E-print Network

Distributed video game streaming system for pervasive gaming A. Jurgelionis1 , F. Bellotti2 , A. De video game streaming system. Newly developed streaming protocols and system architectures enable that the Games@Large system is capable of running video games of different genres, also including First Person

Eisert, Peter

440

Flight Plan Management in a Distributed Air Traffic Control System  

E-print Network

Flight Plan Management in a Distributed Air Traffic Control System Philippe Qu'einnec G control system to replace the existing one. Air traffic control systems are sys­ tems with very high requirement of availability [3]. An important part of an air traffic control system is the flight plan service

Grigoras, .Romulus

441

Snapshots in Hadoop Distributed File System Sameer Agarwal  

E-print Network

Snapshots in Hadoop Distributed File System Sameer Agarwal UC Berkeley Dhruba Borthakur Facebook. #12;Figure 1: HDFS Files 2 Background: HDFS Design Similarly to Google File System [6], Hadoop of any file system, as snapshots enable system adminis- trators to perform data backup and recovery

California at Irvine, University of

442

An Efficient Logging Scheme for Recoverable Distributed Shared Memory Systems  

E-print Network

system environments. Index Terms -- Checkpointing, Distributed shared memory system, Fault tolerant there is a failure [16]. An approach to provide fault­tolerance to the DSM systems is to use checkpointing and rollback recov­ ery. Checkpointing is an operation to save intermedi­ ate system states on the stable

Yeom, Heon Young

443

Integrating security in a group oriented distributed system  

NASA Technical Reports Server (NTRS)

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

Reiter, Michael; Birman, Kenneth; Gong, LI

1992-01-01

444

Automatic code generation for distributed robotic systems  

SciTech Connect

Hetero Helix is a software environment which supports relatively large robotic system development projects. The environment supports a heterogeneous set of message-passing LAN-connected common-bus multiprocessors, but the programming model seen by software developers is a simple shared memory. The conceptual simplicity of shared memory makes it an extremely attractive programming model, especially in large projects where coordinating a large number of people can itself become a significant source of complexity. We present results from three system development efforts conducted at Oak Ridge National Laboratory over the past several years. Each of these efforts used automatic software generation to create 10 to 20 percent of the system.

Jones, J.P.

1993-01-01

445

Automatic code generation for distributed robotic systems  

SciTech Connect

Hetero Helix is a software environment which supports relatively large robotic system development projects. The environment supports a heterogeneous set of message-passing LAN-connected common-bus multiprocessors, but the programming model seen by software developers is a simple shared memory. The conceptual simplicity of shared memory makes it an extremely attractive programming model, especially in large projects where coordinating a large number of people can itself become a significant source of complexity. We present results from three system development efforts conducted at Oak Ridge National Laboratory over the past several years. Each of these efforts used automatic software generation to create 10 to 20 percent of the system.

Jones, J.P.

1993-02-01

446

Impact of Intermittent Wind Distributed Generation on the Reliability of Distribution System  

Microsoft Academic Search

A Monte Carlo simulation approach is proposed in this paper to evaluate the impact of intermittent wind distributed generation on distribution system. Indices providing direct reliability indicators on the addition of WTG are used to reflect the impact. Taking into account the fluctuating nature of wind speed, the random failures of generating units and recognized dependencies, wind speed model, wind

Zeng Ming; Wu Jianhong; Wang Jingjing; Tian Kuo

2010-01-01

447

Integrating the Spiralog File System into the OpenVMS Operating System  

Microsoft Academic Search

Digital' s Spiralog file system is a log-structured file system that makes extensive use of write- back caching. Its technology is substantially different from that of the traditional OpenVMS file system, known as Files-11. The integration of the Spiralog file system into the OpenVMS environment had to ensure that existing appli- cations ran unchanged and at the same time had

Mark A. Howell; Julian M. Palmer

448

A Multidisciplinary, Model-Driven, Distributed Science Data System Architecture  

Microsoft Academic Search

\\u000a The twenty-first century has transformed the world of science by breaking the physical boundaries of distributed organizations\\u000a and interconnecting them into virtual science environments, allowing for systems and systems of systems to seamlessly access\\u000a and share information and resources across highly geographically distributed areas. This e-science transformation is enabling\\u000a new scientific discoveries by allowing for greater collaboration as well as

Daniel J. Crichton; Chris A. Mattmann; John S. Hughes; Sean C. Kelly; Andrew F. Hart

449

A Web browser based DMS-distribution management system  

Microsoft Academic Search

In this paper we describe an application corresponding to a DMS system-distribution management system-that is organized in terms of a distributed multitask client-server architecture. The system is implemented according to the object oriented paradigm leading to a number of objects related with electric devices and specific algorithms. At this level of development, these algorithms correspond to topology processor, state estimation,

M. P. Silva; J. T. Saraiva; A. V. Sousa

2000-01-01

450

Research Challenges for a Scalable Distributed Information Management System  

Microsoft Academic Search

A Scalable Distributed Information Management System (SDIMS) that aggregates information about large-scale networked systems can serve as a basic building for a broad-range of large-scale distributed applications simplifying the design, development, and deployment of such services. In this document, we outline four key requirements such an aggregation system should satisfy to be useful as a general middleware building block -

Praveen Yalagandula; Mike Dahlin

451

Intelligent mapping of communicating processes in distributed computing systems  

Microsoft Academic Search

In this paper we present TEACHER 4.1, a system for designing automatically heuristics that map a set of cmnmunicating processes on a real-time distributed computing system. The problem of optimal promas mapping is NP-hard and involves the optimal placement of precesses on the distributed system and the optimaf routing of messages from one computer to another. The design of efficient

Arthur Ieumwananonthachai; Akiko N. Aizawa; Steven R. Schwartz; Benjamin W. Wah; Jerry C. Yan

1991-01-01

452

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

NASA Technical Reports Server (NTRS)

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

Rogers, J. L., Jr.

1981-01-01

453

HARTOS: a distributed real-time operating system  

Microsoft Academic Search

This paper outlines the design objectives and research goals for HARTOS, a distributed real-time operating system being developed at The University of Michigan. This effort is part of a larger research project to design and implement an experimental distributed real-time system called the Hexagonal Architecture for Real-Time Systems (HARTS). An important feature of HARTS is the use of an intelligent

Dilip D. Kandlur; Daniel L. Kiskis; Kang G. Shin

1989-01-01

454

A Distributed Facilities Automation System For IBM Buildings  

E-print Network

A DISTRIBUTED FACILITIES AUTOMATION SYSTEM FOR IBM BUILDINGS Walter D. Houle, Sr. IBM Corporation Atlanta, Georgia INTRODUCTION Automatic building control systems have rapidly evolved from time-based on-off energy management controllers... to distributed microprocessor-based direct digital control (DDC) Building Automation Systems. Precipitous decreases in the cost of electronic controls have now made it practical and cost effective to install all-electronic controls instead...

Houle, W. D. Sr.

455

Open Architecture Submarine Cable Observatory Systems  

Microsoft Academic Search

The NEPTUNE observatory system has introduced a new technology approach, bringing the Internet to subsea cabled science observatory systems. The subsea nodes, providing subsea connection points provisioning data and power, provide a gateway between the permanent infrastructure and the instrumentation. The proven high reliability and long life of the subsea communications equipment offers the opportunity to install permanent observatories for

N. J. Hazell; G. Waterworth; A. Lecroart

2007-01-01

456

System identification of an open water channel  

Microsoft Academic Search

In this paper, models of the water level in an irrigation channel are derived from system identification experiments. We present the complete system identification procedure from experiment design to model validation, taking into account prior physical information and that the intended use of the models is prediction and control. It is shown that first and second order models capture the

Erik Weyer

2001-01-01

457

INITIAL DISTRIBUTION SYSTEM EVALUATION GUIDANCE MANUAL  

EPA Science Inventory

Guidance to drinking water utilities (community and noncommunity nontransient water systems) and state drinking water administrators (primacy agents) on how to select disinfection byproduct monitoring locations to comply with the requirements of the Stage 2 Disinfectants and Disi...

458

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

NASA Astrophysics Data System (ADS)

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

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

459

Minimizing Energy Consumption in a Water Distribution System: A Systems Modeling Approach  

E-print Network

In a water distribution system from groundwater supply, the bulk of energy consumption is expended at pump stations. These pumps pressurize the water and transport it from the aquifer to the distribution system and to elevated storage tanks. Each...

Johnston, John

2011-08-08

460

Distributed Sensor Coordination for Advanced Energy Systems  

SciTech Connect

The ability to collect key system level information is critical to the safe, efficient and reli- able operation of advanced energy systems. With recent advances in sensor development, it is now possible to push some level of decision making directly to computationally sophisticated sensors, rather than wait for data to arrive to a massive centralized location before a decision is made. This type of approach relies on networked sensors (called “agents” from here on) to actively collect and process data, and provide key control deci- sions to significantly improve both the quality/relevance of the collected data and the as- sociating decision making. The technological bottlenecks for such sensor networks stem from a lack of mathematics and algorithms to manage the systems, rather than difficulties associated with building and deploying them. Indeed, traditional sensor coordination strategies do not provide adequate solutions for this problem. Passive data collection methods (e.g., large sensor webs) can scale to large systems, but are generally not suited to highly dynamic environments, such as ad- vanced energy systems, where crucial decisions may need to be reached quickly and lo- cally. Approaches based on local decisions on the other hand cannot guarantee that each agent performing its task (maximize an agent objective) will lead to good network wide solution (maximize a network objective) without invoking cumbersome coordination rou- tines. There is currently a lack of algorithms that will enable self-organization and blend the efficiency of local decision making with the system level guarantees of global decision making, particularly when the systems operate in dynamic and stochastic environments. In this work we addressed this critical gap and provided a comprehensive solution to the problem of sensor coordination to ensure the safe, reliable, and robust operation of advanced energy systems. The differentiating aspect of the proposed work is in shift- ing the focus towards “what to observe” rather than “how to observe” in large sensor networks, allowing the agents to actively determine both the structure of the network and the relevance of the information they are seeking to collect. In addition to providing an implicit coordination mechanism, this approach allows the system to be reconfigured in response to changing needs (e.g., sudden external events requiring new responses) or changing sensor network characteristics (e.g., sudden changes to plant condition). Outcome Summary: All milestones associated with this project have been completed. In particular, private sensor objective functions were developed which are aligned with the global objective function, sensor effectiveness has been improved by using “sensor teams,” system efficiency has been improved by 30% using difference evaluation func- tions, we have demonstrated system reconfigurability for 20% changes in system con- ditions, we have demonstrated extreme scalability of our proposed algorithm, we have demonstrated that sensor networks can overcome disruptions of up to 20% in network conditions, and have demonstrated system reconfigurability to 20% changes in system conditions in hardware-based simulations. This final report summarizes how each of these milestones was achieved, and gives insight into future research possibilities past the work which has been completed. The following publications support these milestones [6, 8, 9, 10, 16, 18, 19].

Tumer, Kagan

2013-07-31

461

Century Electric Distribution System Operations Lorenzo Kristov,1  

E-print Network

supply to competition, allowing customers greater choice over the sources of energy and creating new Independent System Operator Paul De Martini, Caltech Resnick Institute Introduction The electric industry has 1990s opened up the wholesale markets with numerous competitive generation companies transacting over

Low, Steven H.

462

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

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

463

Reliability cost/worth considerations in distribution system evaluation  

NASA Astrophysics Data System (ADS)

Reliability cost/worth assessment plays an important role in power system planning, operation and expansion as it provides an opportunity to incorporate customer concerns in the analysis. This thesis focuses on the reliability cost/worth analysis of radial distribution systems. Distribution system reliability indices can be evaluated using analytical methods or by Monte Carlo simulation. The sequential simulation technique makes it possible to incorporate the time varying and random nature of load and cost models in the reliability evaluation. This simulation technique can also provide a wide range. of indices and their probability distributions. This research work focuses on distribution system reliability cost/worth evaluation. The main objectives are: (1) the development of analytical and time sequential simulation techniques to evaluate reliability cost/worth indices, (2) the utilization of these techniques in optimal planning and operation decisions, (3) an examination of the effect on reliability worth prediction of time varying load and cost models, and the dispersed nature of cost data, and (4) the consideration of wind generation as an alternative supply in a radial distribution system. An analytical technique designated as the reliability network equivalent approach has been developed to improve the computing efficiency of the conventional failure model and effect analysis method for distribution system reliability evaluation. A time sequential simulation approach is also developed and used to evaluate the basic distribution system reliability indices and their distributions. A generalized analytical technique and a time sequential simulation technique in which the time varying nature of the load and cost models are incorporated in the analysis have been developed and used to evaluate reliability cost/worth indices. These indices are utilized in an optimization process to determine the optimal number of switches and locations in a distribution system. A bisection search technique Is used to simplify the optimization procedure. This thesis also recognizes the impact of different load and cost models and the dispersed nature of cost data on the distribution system reliability indices. The time varying load and cost models for seven different customers have been developed and illustrated The effect of the time varying load and cost models on reliability worth is illustrated by application to several test distribution systems. The effect on the reliability worth indices of the dispersed nature of the cost data is also considered in the, simulation technique. Economic and environment concerns have created an increased interest in the use of wind Economic and environment concerns have created an increased interest in as an alternative energy source. The impact on the reliability performance of a distribution system of using wind generation as an alternative supply is investigated. The effect of different wind sites and wind turbine generator parameters on system reliability is examined.

Wang, Peng

1999-12-01

464

Kicked quantized cavity mode - An open-systems-theory approach  

Microsoft Academic Search

Techniques from the quantum theory of open systems (operations) are applied to the model of a kicked quantized cavity mode presented by Filipowicz et al. (1986). It is noted that these techniques make possible a straightforward discussion of atomic velocity profile in the model, which can be experimentally realized by injecting a low-density beam of Rydberg atoms into a high-Q

G. J. Milburn

1987-01-01

465

A Model Regional Open Learning System. Final Report.  

ERIC Educational Resources Information Center

This 1978 report on the model regional open learning system of the University of Mid-America (UMA), Lincoln, Nebraska, summarizes the activities of the following program areas: course development, delivery, research and dissemination, and governance and administration. Descriptions are provided of courses in the following stages of development:…

McBride, Jack

466

Control of a two Level Open Quantum System  

E-print Network

Control of a two Level Open Quantum System Domenico D'Alessandro Department of Mathematics@iastate.edu, slava@ameslab.gov Abstract We study the control problem for a general (finite di- mensional) quantum use sensitivity functions as a tool to compare control laws and trajectories in this formu- lation. We

Sontag, Eduardo

467

TAMPER-RESILIENT METHODS FOR WEB-BASED OPEN SYSTEMS  

E-print Network

in the College of Computing Georgia Institute of Technology August 2007 Copyright c 2007 by James Caverlee #12;TAMPER-RESILIENT METHODS FOR WEB-BASED OPEN SYSTEMS Approved by: Ling Liu, Advisor College of Computing Georgia Institute of Technology Sham Navathe College of Computing Georgia Institute of Technology William

Liu, Ling

468

Open cycle air turbine solar thermal power system  

Microsoft Academic Search

Solar electrical power generation using a heated air turbine in conjunction with a tower-mounted central receiver and heliostat field can be hybrid fossil fuel fired so as to avoid thermal storage problems. Using a regenerative gas turbine open cycle, no cooling system is required. It is shown that with a solar receiver concept allowing a fast thermal response to transient

E. Le Grives

1979-01-01

469

An open cycle turbine solar thermal power system  

Microsoft Academic Search

Solar electrical power generation using a heated air turbine in conjunction with a tower mounted central receiver and heliostat field was hybrid fossil fuel fired so as to avoid thermal storage problems. Using a regenerative gas turbine open cycle, no cooling system was required. It is shown that with a solar receiver concept allowing a fast thermal response to transient

E. Legrives

1979-01-01

470

Evolution Patterns of Open-Source Software Systems and Communities  

E-print Network

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

Nakakoji, Kumiyo

471

On Manageability and Robustness of Open Multi-Agent Systems  

E-print Network

On Manageability and Robustness of Open Multi-Agent Systems Naftaly H. Minsky and Takahiro Murata) and the robustness of the agent- community under certain unexpected adverse conditions, such as unpre- dictable build a scalable infrastructure that supports monitoring, steering and a degree of robustness, in spite

Minsky, Naftaly

472

Chinese Localisation of Evergreen: An Open Source Integrated Library System  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to investigate various issues related to Chinese language localisation in Evergreen, an open source integrated library system (ILS). Design/methodology/approach: A Simplified Chinese version of Evergreen was implemented and tested and various issues such as encoding, indexing, searching, and sorting…

Zou, Qing; Liu, Guoying

2009-01-01

473

Jumplike unravelings for non-Markovian open quantum systems  

Microsoft Academic Search

Non-Markovian evolution of an open quantum system can be ``unraveled'' into pure state trajectories generated by a non-Markovian stochastic (diffusive) Schrödinger equation, as introduced by Diósi, Gisin, and Strunz. Recently we have shown that such equations can be derived using the modal (hidden variable) interpretation of quantum mechanics. In this paper we generalize this theory to treat jumplike unravelings. To

Jay Gambetta; T. Askerud; H. M. Wiseman

2004-01-01

474

Fractal Weyl law behavior in an open, chaotic Hamiltonian system  

E-print Network

We numerically show fractal Weyl law behavior in an open Hamiltonian system that is described by a smooth potential and which supports numerous above-barrier resonances. This behavior holds even relatively far away from the classical limit. The complex resonance wave functions are found to be localized on the fractal classical repeller.

Jordan A. Ramilowski; S. D. Prado; F. Borondo; David Farrelly

2009-11-05

475

An Approach for Recovering Distributed System Architectures  

Microsoft Academic Search

Reasoning about software systems at the architectural level is key to effective software development, management, evolution and reuse. All too often, though, the lack of appropriate documentation leads to a situation where architectural design information has to be recovered directly from implemented software artifacts. This is a very demanding process, particularly when involving recovery of runtime abstractions (clients, servers, interaction

Nabor C. Mendonça; Jeff Kramer

2001-01-01

476

Residential hot water distribution systems: Roundtablesession  

SciTech Connect

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

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

2002-08-01

477

Computing Replica Placement in Distributed Systems  

Microsoft Academic Search

IntroductionThe actual gains in availability, reliability andperformance which are achieved by object replication area complex function of many factors including thenumber of replicas, the placement of those replicas, thenature of the transactions performed on the replicatedobject, the choice of replication protocols and theavailability and performance characteristics of themachines and networks composing the system. Forexample, consider a naming or directory service

Daniel L. Mccue; Mark C. Little

1992-01-01

478

Epidemic Information Dissemination in Distributed Systems  

Microsoft Academic Search

Easy to deploy, robust, and highly resilient to failures, epidemic algorithms are a potentially effective mechanism for propagating information in large peer-to-peer systems deployed on Internet or ad hoc networks. It is possible to adjust the parameters of epidemic algorithm to achieve high reliability despite process crashes and disconnections, packet losses, and a dynamic network topology. Although researchers have used

Patrick Th. Eugster; Rachid Guerraoui; Anne-marie Kermarrec; Laurent Massoulié

2004-01-01

479

Distributed geographic information systems in forest management  

Microsoft Academic Search

Managing a forest in the present implies a look towards the future and, in the field of geographic information systems (GIS), it involves the interoperability of existing data and information, which are increasingly determinant in intelligent forest planning and management. Recognizing the global importance of forests in economic, environmental and social dimensions presents a new challenge for those interested in

Andre Barriguinha; Pedro Cabral; Miguel Neto

2011-01-01

480

PREDICTING WATER QUALITY IN DISTRIBUTION SYSTEMS  

EPA Science Inventory

The quality of a public water supply although acceptable when it leaves the treatment plant, may deteriorate before it reaches the user. Deterioration may be caused by either chemical or biological transformations or by a loss of system integrity. There have been a growing number...

481

Distributed control and computation in a parallel modular robotic system  

NASA Astrophysics Data System (ADS)

New generations of modular and reconfigurable robotic systems with many degrees of freedom can be transformed to achieve different functions, modes of manipulation, and means of mobility resulting in efficient multifunctional systems which adapt to complex environments. The design of modular distributed algorithms and architectures for control of these systems is particularly challenging since kinematic and dynamic performance must be maintained throughout a range of alternative physical reconfigurations. The 'Tetrobot' is a prototype modular system using parallel, variable geometry truss-like mechanisms which can be reconfigured to create moving platforms, walking machines, manipulator arms, a pipe crawler and other devices. Modular algorithms for distributed control and dynamic redundancy resolution of these system will be discussed, and the principles of distributed control for modular systems generalize beyond these specific mechanisms. The resulting Tetrobot system has a range of interesting applications including space robotics, construction, mining, medical, undersea, and flexible manufacturing.

Lee, Woo H.; Sanderson, Arthur C.

1999-08-01

482

Energy loss analysis of an integrated space power distribution system  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

483

Seismic Fragility of the LANL Fire Water Distribution System  

SciTech Connect

The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10{sup -3} that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels. Assumptions are presented in Section 2.2 of this report.

Greg Mertz

2007-03-30

484

A distributed timing system for sychronizing control and data correlation  

SciTech Connect

Synchronization is necessary in experimental physics machines to provide positive control over related events. The Ground Test Accelerator (GTA) timing system provides this function through a distributed control system, known as the Experimental Physics and Industrial Control System (EPICS). The EPICS timing system was designed to take advantage of a distributed architecture, and provides time stamping for synchronous data correlation as well as event control. The system has been successfully demonstrated on over a dozen controller nodes for operation and data analysis. The design of the hardware, software, and operational results are discussed.

Stettler, M.; Thout, M.; Dalesio, L.R.; Cole, R.; Fite, C.; Slentz, G.; Warren, D.

1992-09-01

485

Dynamic current distribution controls of a parallel connected converter system  

Microsoft Academic Search

Based on the central-limit control algorithm for the parallel connected converter system, two improved dynamic current distribution control methods are introduced: the programmable current distribution control (PCDC) and the maximum current limit control (MCLC). In PCDC, the ratio of the output current of each converter to the total output current can be programmed according to the desired application objective while

C. Q. Lee; K. Siri; T.-F. Wu

1991-01-01

486

Adaptive cache-driven request distribution in clustered EJB systems  

Microsoft Academic Search

This paper presents an algorithm for request distribution in clustered EJB systems. A classification for EJB requests is first introduced, on which request distribution is based. The objective is to achieve load balancing and to enhance the caching performance in the EJB containers. The algorithm is based on periodically collecting traffic statistics from the EJB containers, and then solving a

Hazem Elmeleegy; Noha Adly; Magdy Nagi

2004-01-01

487

A Smart Energy System: Distributed Resource Management, Control and Optimization  

E-print Network

A Smart Energy System: Distributed Resource Management, Control and Optimization Yong Ding, Student of distributed energy resource and consumption management, which proposes to design a networked and embedded platform for realizing a dynamic energy mix and optimizing the energy consumption dy- namically. Based

Beigl, Michael