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1

Open distributed supervisory system design using Petri nets  

Microsoft Academic Search

The design of supervisory system for automated environments can be seen as a task involving techniques and methods of two main areas: software and control engineering. In this context, the purpose of this work is to introduce a new approach for open distributed supervisory system design based on the merging of traditional techniques of software engineering (such as object-oriented concepts)

G. Bastidas; E. Villani; F. Junqueira; P. E. Miyagi

2003-01-01

2

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

3

The Delta4 approach to dependability in open distributed computing systems  

Microsoft Academic Search

As part of the European Strategic Programme for Research in Information Technology (ESPRIT), the Delta-4 project is seeking to define an open, fault-tolerant, distributed computing architecture. The authors present the overall Delta-4 framework for open, fault-tolerant, distributed computing systems and sketch the current implementation, which is based on a local area network with specific atomic multicasting and error-processing protocols for

D. Powell; G. Bonn; D. Seaton; P. Verissimo; F. Waeselynck

1988-01-01

4

Modeling and simulation for performance estimation of open distributed energy management systems  

Microsoft Academic Search

This paper describes a performance estimation tool developed for modeling and simulation of open distributed energy management systems to support their design. The approach of discrete event simulation with detailed models is considered for efficient performance estimation. The tool includes basic models constituting a platform, e.g., Ethernet, communication protocol, operating system, etc. Application softwares are modeled by specifying CPU time,

S. Horiike; Y. Okazaki

1995-01-01

5

Modeling and simulation for performance estimation of open distributed energy management systems  

Microsoft Academic Search

This paper describes a performance estimation tool developed for modeling and simulation of open distributed energy management systems to support their design. The approach of discrete event simulation with detailed models is considered for efficient performance estimation. The tool includes basic models constituting a platform, e.g. Ethernet, communication protocol, operating system, etc. Application softwares are modeled by specifying CPU time,

S. Horiike; Y. Okazaki

1996-01-01

6

TPCC-UVa: An Open-Source TPC-C Implementation for Parallel and Distributed Systems  

E-print Network

, such as the SPEC CPU2000 bench- mark suite [2], the NAS Parallel Benchmark [5] and the OLDEN benchmarks [8], amongTPCC-UVa: An Open-Source TPC-C Implementation for Parallel and Distributed Systems Diego R. Llanos,b.palop}@infor.uva.es Abstract This paper presents TPCC-UVa, an open-source im- plementation of the TPC-C benchmark intended

Llanos, Diego R.

7

The design of an open system with distributed real-time requirements  

Microsoft Academic Search

This paper describes some of the US Navy's New Attack Submarine C3I system - an open system with distributedreal-time requirements. It also presents our research design and prototyping efforts that address these requirements.It concludes by discussing several areas where further research is needed to allow open systems to better supportreal-time applications.1 IntroductionWith the advent of U.S. government mandates for open

Roman Ginis; Victor Fay Wolfe; Janet J. Prichard

1996-01-01

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

The Earth System Grid Federation: An Open Infrastructure for Access to Distributed Geospatial 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).

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

2013-01-01

10

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

11

Phase-type distributions and representations: Some results and open problems for system theory  

Microsoft Academic Search

In this paper we consider phase-type distributions. These distributions correspond to the random hitting time of an absorbing Markov chain. They are used for modelling various random times, in particular, those which appear in manufacturing systems as processing times, times to failure, repair times, etc. The Markovian nature of these distributions allows the use of very efficient matrix based computer

Christian Commault; Stéphane Mocanu

2003-01-01

12

The Design of an Open System with Distributed RealTime Requirements  

E-print Network

@cs.ecu.edu Abstract This paper describes some of the US Navy's New Attack Submarine C3I system ­ an open system in specifying the requirements and a possible design of aspects of the US Navy's New Attack Submarine (NSSN

Rhode Island, University of

13

Developing Components of a Distributed Earth System Observatory using Open Source Technology  

Microsoft Academic Search

We present recent progress in the development of an Earth System Observatory at the University of New Hampshire. This effort combines existing open source geoinformatics tools, and focuses on custom, lightweight, and simple interfaces for querying and performing data manipulation with mathematical and conditional queries, and displaying results as maps and data tables. We also consider the extent to which

B. Braswell; C. Vorosmarty; A. Magill; B. Fekete; S. Glidden; D. Justice; A. Schloss; A. Proussevitch; M. Fahnestock

2006-01-01

14

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

Microsoft Academic Search

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

Nigel Davies; Kerry Raymond; Gordon S. Blair

1999-01-01

15

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

16

Open Clients for Distributed Databases  

NASA Astrophysics Data System (ADS)

We are actively developing a collection of open source example clients that demonstrate use of our "back end" data management infrastructure. The data management system is reported elsewhere at this meeting (Arko and Chayes: A Scaleable Database Infrastructure). In addition to their primary goal of being examples for others to build upon, some of these clients may have limited utility in them selves. More information about the clients and the data infrastructure is available on line at http://data.ldeo.columbia.edu. The available examples to be demonstrated include several web-based clients including those developed for the Community Review System of the Digital Library for Earth System Education, a real-time watch standers log book, an offline interface to use log book entries, a simple client to search on multibeam metadata and others are Internet enabled and generally web-based front ends that support searches against one or more relational databases using industry standard SQL queries. In addition to the web based clients, simple SQL searches from within Excel and similar applications will be demonstrated. By defining, documenting and publishing a clear interface to the fully searchable databases, it becomes relatively easy to construct client interfaces that are optimized for specific applications in comparison to building a monolithic data and user interface system.

Chayes, D. N.; Arko, R. A.

2001-12-01

17

Development of an open, event-based and platform independent architecture for distributed and intelligent control systems  

Microsoft Academic Search

New developments confirm the trend of autonomous distributed control systems in the field of manufacturing and automation. To fulfill this demand a new concept of the design of control systems is required in which the structure, the interfaces and communication and interaction opportunities with no restrictions to the platform or hardware are defined. The concept presented in this paper is

K. Feldmann; W. Wolf; M. Weber

2004-01-01

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

Open systems storage platforms  

NASA Technical Reports Server (NTRS)

The building blocks for an open storage system includes a system platform, a selection of storage devices and interfaces, system software, and storage applications CONVEX storage systems are based on the DS Series Data Server systems. These systems are a variant of the C3200 supercomputer with expanded I/O capabilities. These systems support a variety of medium and high speed interfaces to networks and peripherals. System software is provided in the form of ConvexOS, a POSIX compliant derivative of 4.3BSD UNIX. Storage applications include products such as UNITREE and EMASS. With the DS Series of storage systems, Convex has developed a set of products which provide open system solutions for storage management applications. The systems are highly modular, assembled from off the shelf components with industry standard interfaces. The C Series system architecture provides a stable base, with the performance and reliability of a general purpose platform. This combination of a proven system architecture with a variety of choices in peripherals and application software allows wide flexibility in configurations, and delivers the benefits of open systems to the mass storage world.

Collins, Kirby

1992-01-01

20

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

21

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, V.; Dixon, K.; Laverdure, N.; Knudsen, P.; Arenius, D. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States); Barrios, M.; Jones, S.; Johnson, M.; Casagrande, F. [Facility for Rare Isotope Beams (FRIB), Michigan State University, East Lansing, MI 48824 (United States)

2014-01-29

22

SPECIALISSUE DISTRIBUTED SYSTEMS  

E-print Network

guides and controls a flock of birds or a school of fish? The answers to these questions involve examplesSPECIALISSUE DISTRIBUTED SYSTEMS Growth of distributed systemshas attained unstoppablemomentum their implementation with more confidence. LEONARD KLEINROCK DISTRIBUTED SYSTEMS IN NATURE How did the killer bees find

Newhall, Tia

23

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

24

Distribution system grounding fundamentals  

Microsoft Academic Search

The most common medium voltage electric distribution system in the United States is multigrounded wye using a common neutral for both primary and secondary systems. The effective interconnection of the multigrounded wye neutral conductor with the earth ground reference is very important for safe and effective operation of these systems. Areas of concern include: public safety, operating personnel safety, system

Edward S. Thomas; Richard A. Barber; J. B. Dagenhart; A. L. Clapp

2004-01-01

25

75 FR 72686 - Express Mail Open and Distribute and Priority Mail Open and Distribute  

Federal Register 2010, 2011, 2012, 2013

...product; and adding a five-pound minimum weight requirement for Express Mail Open and...concerns about the five-pound minimum weight limit for Express Mail Open and Distribute...is establishing a five-pound minimum weight requirement for all Express Mail...

2010-11-26

26

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

27

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

28

DIstributed VIRtual System (DIVIRS) project  

NASA Technical Reports Server (NTRS)

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

Schorr, Herbert; Neuman, Clifford B.

1995-01-01

29

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

30

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

NASA Astrophysics Data System (ADS)

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

Kanmani, S.; Gandhimathi, R.

2013-06-01

31

Distributed Computerized Catalog System  

NASA Technical Reports Server (NTRS)

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

Borgen, Richard L.; Wagner, David A.

1995-01-01

32

Distribution system grounding fundamentals  

Microsoft Academic Search

This article is an overview of the various relationships between neutral currents, ground currents, electrode impedances, and voltage potentials that are encountered in the operation of multi-grounded wye distribution systems. This system continuation is the most commonly used configuration among U.S. domestic utilities. Voltages range from 4.16\\/2.4 kV to 34.5\\/19.9 kV. The most common system voltages are 15- and 25-kV

EDWARD S. THOMAS; JOHN B. DAGENHART; RICHARD A. BARBER; ALLEN L. CLAPP

2005-01-01

33

Open quantum systems and random matrix theory  

NASA Astrophysics Data System (ADS)

A simple model for open quantum systems is analyzed with random matrix theory. The system is coupled to the continuum in a minimal way. In this paper the effect on the level statistics of opening the system is seen. In particular the ?3(L ) statistic, the width distribution and the level spacing are examined as a function of the strength of this coupling. The emergence of a super-radiant transition is observed. The level spacing and ?3(L ) statistics exhibit the signatures of missed levels or intruder levels as the super-radiant state is formed.

Mulhall, Declan

2015-01-01

34

Distributed Optimization System  

DOEpatents

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

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

2004-11-30

35

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

36

Distribution system reliability indices  

SciTech Connect

Distribution system reliability assessment can be divided into two basic segments of measuring past performance and predicting future performance. This paper compares the results obtained from tow surveys dealing with United States and Canadian utility activities in regard to service continuity data collection and utilization. The paper also presents a summary of service continuity statistics for those Canadian utilities that participate in the Canadian Electrical Association annual service continuity reports.

Billinton, R.; Billinton, J.E.

1989-01-01

37

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

38

Automated Gas Distribution System  

NASA Astrophysics Data System (ADS)

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

Starke, Allen; Clark, Henry

2012-10-01

39

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

40

Distributed road assessment system  

DOEpatents

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

Beer, N. Reginald; Paglieroni, David W

2014-03-25

41

Dynamics of explosive paroxysms at open-vent andesitic systems: High-resolution mass distribution analyses of the 2006 Tungurahua fall deposit (Ecuador)  

NASA Astrophysics Data System (ADS)

Long-lasting andesitic eruptions sometimes include strong short-lived explosive events, which can pose significant hazards in populated regions. The origin and dynamics of such violent eruptions remain poorly known and may involve a combination of different factors. Tungurahua volcano, Ecuador, reawakens in 1999 and is an example of such an open-vent system that experienced a strong and deadly andesitic pyroclastic flow-forming event in August 2006. Inspection of the deposits suggested that the event could have been triggered by magma mixing (coexistence of both silicic pumices and andesitic scoria in the tephra), magma-water interaction (presence of xenolithic clasts) or deep andesitic magma reinjection (based on mineral chemistry). Here we investigate these options by performing a high-resolution mass budget analysis of the scoria fall deposit. This is achieved by analysing componentry compositions and their mass distribution pattern in the layer, which allow us to document and integrate exponential and power laws mass decay rates over wide areas. The results yield a total mass for the tephra layer of ˜2×1010 kg. The pumice mass fraction is far too small (<0.4%) to account for the high explosivity of the 2006 event. Similarly, the xenoclastic mass fraction is unexpectedly small (0.2%) and suggests limited magma-water interaction. Instead, we interpret these xenoclasts as a result of upper conduit erosion at a rate of ˜30 cm/h during the paroxysm. Altogether our results support an explosive event fed by a deep gas-rich andesitic reinjection, which would have incorporated a pocket of older differentiated magma and eroded the upper conduit during the sub-plinian event. The high-resolution mass-based approach reveals useful to decipher the origin of the violent 2006 paroxysm and has potential to improve magnitude determinations of ancient eruption by considering componentry mass instead of volume. It is also applicable for monitoring purposes in the context of ongoing crises at andesitic volcanoes worldwide

Eychenne, Julia; Le Pennec, Jean-Luc; Ramón, Patricio; Yepes, Hugo

2013-01-01

42

Tsallis Entropy Based Velocity Distribution in Open Channel Flows  

E-print Network

The Tsallis entropy is applied to derive both 1-D and 2-D velocity distributions in an open channel cross section. These distributions contain a parameter m through which the Tsallis entropy becomes a generalization of the Shannon entropy. Different...

Luo, Hao

2010-07-14

43

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

44

Distributed Intrusion Detection System  

NSDL National Science Digital Library

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

45

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

46

The Distributed Annotation System  

PubMed Central

Background Currently, most genome annotation is curated by centralized groups with limited resources. Efforts to share annotations transparently among multiple groups have not yet been satisfactory. Results Here we introduce a concept called the Distributed Annotation System (DAS). DAS allows sequence annotations to be decentralized among multiple third-party annotators and integrated on an as-needed basis by client-side software. The communication between client and servers in DAS is defined by the DAS XML specification. Annotations are displayed in layers, one per server. Any client or server adhering to the DAS XML specification can participate in the system; we describe a simple prototype client and server example. Conclusions The DAS specification is being used experimentally by Ensembl, WormBase, and the Berkeley Drosophila Genome Project. Continued success will depend on the readiness of the research community to adopt DAS and provide annotations. All components are freely available from the project website . PMID:11667947

Dowell, Robin D; Jokerst, Rodney M; Day, Allen; Eddy, Sean R; Stein, Lincoln

2001-01-01

47

Continuous flow systems. Distribution of residence times  

Microsoft Academic Search

When a fluid flows through a vessel at a constant rate, either “piston-flow” or perfect mixing is usually assumed. In practice, many systems do not conform to either of these assumptions, so that calculations based on them may be inaccurate. It is explained how distribution-functions for residence-times can be defined and measured for actual systems. Open and packed tubes are

P. V. Danckwerts

1995-01-01

48

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

49

Systems architecture for distributed applications  

NASA Technical Reports Server (NTRS)

This paper describes the kernel of a distributed operating system called ADAPT. The system runs on top of existing single host operating systems that are networked together. It's purpose is to transform this network of individual systems into a single system that will be easier for application programmers to use. This single system need not be monolithic; ADAPT facilitates the construction of both integrated and modular distributed systems.

Peebles, R.

1980-01-01

50

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

51

Load Balancing in Distributed Systems  

Microsoft Academic Search

In a distributed computing system made up of different types of processors each processor in the system may have different performance and reliability characteristics. In order to take advantage of this diversity of processing power, a modular distributed program should have its modules assigned in such a way that the applicable system performance index, such as execution time or cost,

Timothy C. K. Chou; Jacob A. Abraham

1982-01-01

52

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

53

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

54

Gossiping in distributed systems  

E-print Network

Exchange of information between various nodes in a distributed network can be useful to utilize the available resources effectively. Gossiping algorithms can be used for this purpose. We begin with a survey of various gossiping schemes for different...

Penubothu, Muralidhar V

1994-01-01

55

Open systems for plant process computers  

SciTech Connect

Arizona Public Service (APS) Company recently upgraded the Emergency Response Facility (ERF) computer at the Palo Verde Nuclear Generating Stations (PVNGS). The project was initiated to provide the ability to record and display plant data for later analysis of plant events and operational problems (one of the great oversights at nearly every nuclear plant constructed) and to resolve a commitment to correct performance problems on the display side of the system. A major forming objective for the project was to lay a foundation with ample capability and flexibility to provide solutions for future real-time data needs at the plants. The Halliburton NUS Corporation`s Idaho Center (NUS) was selected to develop the system. Because of the constant changes occurring in the computer hardware and software industry, NUS designed and implemented a distributed Open Systems solution based on the UNIX Operating System. This Open System is highly portable across a variety of computer architectures and operating systems and is based on NUS` R*TIME{reg_sign}, a mature software system successfully operating in 14 nuclear plants and over 80 fossil plants. Along with R*TIME, NUS developed two Man-Machine Interface (MMI) versions: R*TIME/WIN, a Microsoft Windows application designed for INTEL-based personal computers operating either Microsoft`s Windows 3.1 or Windows NT operating systems; and R*TIME/X, based on the standard X Window System utilizing the Motif Window Manager.

Norris, D.L. [Halliburton NUS, Idaho Falls, ID (United States); Pate, R.L. [Arizona Public Service Co., Phoenix, AZ (United States)

1995-03-01

56

Automated Power-Distribution System  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

57

Software Development for Distributed Systems  

Microsoft Academic Search

My prime interest in participating in this session is to project the applicability of SP to the development of software for Distributed Computer Systems (such as the UC Irvine Distributed Computer System and the CMU C.MMP). The difficulties common to all software design and development efforts are made even more acute when writing software for a DCS. Setting up experiments

D. J. Faber

1975-01-01

58

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

59

Water Treatment Technology - Distribution Systems.  

ERIC Educational Resources Information Center

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

Ross-Harrington, Melinda; Kincaid, G. David

60

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

61

Control of distributed UPS systems  

Microsoft Academic Search

This paper is concerned with the control aspects of distributed uninterruptible power supply (UPS) systems. These are systems in which the UPS units and the critical loads are located flexibly in an interconnected network in the manner of a typical power system. Decentralized control without data communication is an essential control requirement for such systems. The main aim of this

M. C. Chandrokar; D. M. Divan; B. Banerjee

1994-01-01

62

Distributed proximity sensor system  

NASA Technical Reports Server (NTRS)

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

Lee, Sukhan (inventor)

1988-01-01

63

Integrated distribution control and protection system  

SciTech Connect

A prototype distribution automation system incorporating protection, control, and monitoring functions has been developed, installed, and operated at a utility substation. The system, which employs a distributed microprocessor-based architecture, is of interest to electric utilities because of its potential to improve use of power system facilities, enhance system operation, reduce outage duration, and provide more timely information for system planning. The project team developed a system functional specification and used specialized computer software to improve and expand previously implemented programs for automatic control functions. In addition, team members developed computer programs for digital feeder protection functions, designed and developed prototype hardware for the subsystems, and developed resident firmware. Finally, they installed and operated the completed system at a Texas Utility Electric Company substation in Fort Worth, Texas, and evaluated results of the one-year demonstration, which included open- and closed-loop testing of all functions. The outcome of this project indicated that reliable digital feeder protection could be accomplished, automatic control functions could be implemented to improve power system operation efficiency, and secure digital data communications could be achieved in the substation environment. As a result of the successful demonstration of these capabilities, GE has embarked on the commercial development of digital products that perform selected functions from the integrated distribution control and protection system.

Not Available

1991-12-01

64

Main Injector power distribution system  

SciTech Connect

The paper describes a new power distribution system for Fermilab's Main Injector. The system provides 13.8 kV power to Main Injector accelerator (accelerator and conventional loads) and is capable of providing power to the rest of the laboratory (backfeed system). Design criteria, and features including simulation results are given.

Cezary Jach and Daniel Wolff

2002-06-03

65

Toward Distributed Declarative Control of Networked Cyber-Physical Systems  

Microsoft Academic Search

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

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

2010-01-01

66

Distributed Control of Positive Systems  

E-print Network

For positive systems, and more generally positively dominated systems, it is shown that distributed H-infinity optimal controllers can be computed using linear programming, with a complexity that scales linearly with the number of states and interconnections. Hence two fundamental advantages are achieved compared to classical methods for multi-variable control: Distributed implementations and scalable computations. The results are illustrated by examples from control of mechanical structures, transportation networks and electrical power transmission.

Rantzer, Anders

2012-01-01

67

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

68

Fractal Weyl laws for chaotic open systems  

E-print Network

We present a result relating the density of quantum resonances for an open chaotic system to the fractal dimension of the associated classical repeller. The result is supported by numerical computation of the resonances of the system of n disks on a plane. The result generalizes the Weyl law for the density of states of a closed system to chaotic open systems.

W. T. Lu; S. Sridhar; Maciej Zworski

2003-05-30

69

Distribution of resonances in the quantum open baker map  

NASA Astrophysics Data System (ADS)

We study relevant features of the spectrum of the quantum open baker map. The opening consists of a cut along the momentum p direction of the 2-torus phase space, modeling an open chaotic cavity. We study briefly the classical forward trapped set and analyze the corresponding quantum nonunitary evolution operator. The distribution of eigenvalues depends strongly on the location of the escape region with respect to the central discontinuity of this map. This introduces new ingredients to the association among the classical escape and quantum decay rates. Finally, we could verify that the validity of the fractal Weyl law holds in all cases.

Pedrosa, Juan M.; Carlo, Gabriel G.; Wisniacki, Diego A.; Ermann, Leonardo

2009-01-01

70

Controlling distributed energy constrained resources for power system ancillary services  

Microsoft Academic Search

Demand response, load control and control of distributed energy storage devices are gaining attention as mechanisms to support power system operation in “smart grids”, for example by providing ancillary services such as spinning reserves and regulation. This paper addresses some of the key open questions in developing algorithms to communicate with and control large populations of distributed resources, and borrows

Ashwin Kashyap; Duncan Callaway

2010-01-01

71

Open source portal to distributed image repositories  

Microsoft Academic Search

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

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

2004-01-01

72

Automated Power-Distribution System  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

73

A Distributed Object Tracing System  

Microsoft Academic Search

Trace-based analysis has always been used to guide and motivate more effective hardware and software design. Existing traces available, however, are unsuitable for studying object-based storage system, a very active area of current storage research, because they are collected from the traditional file systems and don't contain information about object. Thus, a kind of distributed object tracing system is presented

Ke Zhou; Chun-hua Li; Dan Feng; Yang Wang; Liang Lu; Yong-guang Ji

2006-01-01

74

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

75

An Open Framework for Distributed Context Management in Ubiquitous Environment  

Microsoft Academic Search

In this paper, we aim to propose an open framework for ubiquitous environment. In this framework, a distributed context management architecture and a communication model based on standard protocols are proposed. With this framework, a smart device is able to join to the ubiquitous environment and search for context-aware services based on standard protocols, such as UPnP and DNS. A

Jun-Hong Lu; Chiung-Ying Wang; Ren-Hung Hwang

2009-01-01

76

Maintaining consistency in distributed systems  

NASA Technical Reports Server (NTRS)

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

Birman, Kenneth P.

1991-01-01

77

Air distribution effectiveness with stratified air distribution systems  

E-print Network

1 Air distribution effectiveness with stratified air distribution systems Kisup Lee* Zheng Jiang, Ph.D Qingyan Chen, Ph.D. Student Member ASHRAE Fellow ASHRAE ABSTRACT Stratified air distribution systems such as Traditional Displacement Ventilation (TDV) and Under- Floor Air Distribution (UFAD

Chen, Qingyan "Yan"

78

Research Challenges in Distributed Cyber-Physical Systems  

Microsoft Academic Search

Moore's law, automation considerations, and the pervasive need for timely information lead to a next generation of distributed systems that are open, highly interconnected, and deeply embedded in the physical world. Such systems, called cyber-physical, were recently named the first research priority in networking and information technology in the US by the nation's presidential council of advisors on science and

Tarek F. Abdelzaher

2008-01-01

79

Properly Understanding the Impacts of Distributed Resources on Distribution Systems  

SciTech Connect

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

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

2010-01-01

80

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

81

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

82

A Distributed Visual Surveillance System  

Microsoft Academic Search

We present a distributed vision-based surveillance sys- tem. The system acquires and processes grey level images through one or multiple Camera Units monitoring certain area(s) via a Local Area Network (LAN) and is capable of combining information from multiple Camera Units to obtain a consensus decision. It can be trained to detect cer- tain type of intrusions, for example pedestrians,

Xiaojing Yuan; Zehang Sun; Yaakov L. Varol; George Bebis

2003-01-01

83

Transparent Recovery in Distributed Systems  

Microsoft Academic Search

We are investigating transparent optimistic solutions to problems in dis-tributed systems such as recovery [6], replication [3], parallelization [2], and concurrent competing alternatives [4]. By a transparent solution to such a problem we mean that a program is transformed automatically, and that the behavior of the program is equivalent to a possible behavior of the un-transformed program; in addition, the

David F. Bacon

1991-01-01

84

Perturbative approach to Markovian open quantum systems  

PubMed Central

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

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

2014-01-01

85

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

ERIC Educational Resources Information Center

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

Breeding, Marshall

2005-01-01

86

The ATLAS distributed analysis system  

NASA Astrophysics Data System (ADS)

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

Legger, F.; Atlas Collaboration

2014-06-01

87

Staggered repulsion of transmission eigenvalues in symmetric open mesoscopic systems  

NASA Astrophysics Data System (ADS)

Quantum systems with discrete symmetries can usually be desymmetrized, but this strategy fails when considering transport in open systems with a symmetry that maps different openings onto each other. We investigate the joint probability density of transmission eigenvalues for such systems in random-matrix theory. In the orthogonal symmetry class we show that the eigenvalue statistics manifests level repulsion only between every second transmission eigenvalue. This finds its natural statistical interpretation as a staggered superposition of two eigenvalue sequences. For a large number of channels, the statistics for a system with a lead-transposing symmetry approaches that of a superposition of two uncorrelated sets of eigenvalues as in systems with a lead-preserving symmetry (which can be desymmetrized). These predictions are confirmed by numerical computations of the transmission-eigenvalue spacing distribution for quantum billiards and for the open kicked rotator.

Kopp, Marten; Schomerus, Henning; Rotter, Stefan

2008-08-01

88

An expert system operational aid for restoration and loss reduction of distribution systems  

Microsoft Academic Search

An application of expert system techniques to the restoration of distribution systems is reported. Primary feeders are typically radial in structure. To increase system reliability, neighboring feeders are connected through a normally open tie switch. When load zones on a feeder interrupted due to a fault, system operators need to identify neighboring feeders and try to restore customers through the

C.-C. Liu; S. J. Lee; S. S. Venkata

1988-01-01

89

CEBAF Distributed Data Acquisition System  

SciTech Connect

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

Trent Allison; Thomas Powers

2005-05-01

90

An Open Distributed Architecture for Sensor Networks for Risk Management  

PubMed Central

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

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

2008-01-01

91

Collaborative naming in distributed systems  

NASA Astrophysics Data System (ADS)

Proposes an alternative naming model for distributed systems which is specifically oriented towards support for naming in group work (for example, in applications such as joint editing and computer conferencing). The goal of the model is to allow a great deal of flexibility in naming and to support both individual and group use of names. A particular focus of the work is on mechanisms for evolving from the initial use of individual names towards common names for objects in a given group context as well as for translating names between different group members and gradually propagating changes in names. The overall aim of the paper is that this model could influence the design of future distributed CSCW systems and also suggest extensions to current name servers and directories. The authors discuss the requirements of a group oriented naming mechanism. They then focus on a flexible model of naming within a single naming context. Once this is established, they then look at how naming contexts could be federated in order to provide a more structured namespace suitable for large scale distributed systems.

Benford, S.; Lee, Ok-Ki

1993-12-01

92

Adaptive diagnosis in distributed systems.  

PubMed

Real-time problem diagnosis in large distributed computer systems and networks is a challenging task that requires fast and accurate inferences from potentially huge data volumes. In this paper, we propose a cost-efficient, adaptive diagnostic technique called active probing. Probes are end-to-end test transactions that collect information about the performance of a distributed system. Active probing uses probabilistic reasoning techniques combined with information-theoretic approach, and allows a fast online inference about the current system state via active selection of only a small number of most-informative tests. We demonstrate empirically that the active probing scheme greatly reduces both the number of probes (from 60% to 75% in most of our real-life applications), and the time needed for localizing the problem when compared with nonadaptive (preplanned) probing schemes. We also provide some theoretical results on the complexity of probe selection, and the effect of "noisy" probes on the accuracy of diagnosis. Finally, we discuss how to model the system's dynamics using dynamic Bayesian networks (DBNs), and an efficient approximate approach called sequential multifault; empirical results demonstrate clear advantage of such approaches over "static" techniques that do not handle system's changes. PMID:16252819

Rish, Irina; Brodie, Mark; Ma, Sheng; Odintsova, Natalia; Beygelzimer, Alina; Grabarnik, Genady; Hernandez, Karina

2005-09-01

93

Television Distribution System for Primary Schools.  

ERIC Educational Resources Information Center

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

South Australia Education Dept., Adelaide.

94

Development of an Integrated Distribution Management System  

Microsoft Academic Search

This final report details the components, functionality, costs, schedule and benefits of developing an Integrated Distribution Management System (IDMS) for power distribution system operation. The Distribution Automation (DA) and Supervisory Control and Data Acquisition (SCADA) systems used by electric power companies to manage the distribution of electric power to retail energy consumers are vital components of the Nations critical infrastructure.

Schatz; Joe E

2010-01-01

95

Explicit Knowledge Distribution in an Omnidirectional Distributed Vision System  

E-print Network

Explicit Knowledge Distribution in an Omnidirectional Distributed Vision System E. Menegatti , G. Cicirelli §, C. Simionato , T. D'Orazio §, E. Pagello , H. Ishiguro Intelligent Autonomous Systems Dis- tributed Vision System that learns to navigate a robot in an office-like environment without any

Menegatti, Emanuele

96

Parallel and distributed information systems  

SciTech Connect

As you know, this conference focuses specifically on the management of information in parallel or distributed systems. Due to the emergence of new applications, we are seeing many new advances in the field. These application areas include multimedia data on demand, the information superhighway, data mining in large commercial and scientific databases, and mobile computing. Concurrent with these new applications, we are witnessing changes in the both research and commercial computing environments - high-end computing, once the domain of traditional mainframes, is being replaced by parallel processors based on off-the-shelf components. At the low end, personal digital assistants and personal communication services point to the emergence of a large consumer-oriented distributed information environment. In between, the client/server model long familiar to research environments has become commonplace in business computing.

Not Available

1994-01-01

97

Distributed antenna system and method  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

98

Modeling distributed hybrid systems in Ptolemy II  

Microsoft Academic Search

We present Ptolemy II as a modeling and simulation environment for distributed hybrid systems. In Ptolemy II, a distributed hybrid system is specified as a hierarchy of models: an event-based top level and distributed islands of hybrid systems. Each hybrid system is in turn a hierarchy of continuous-time models and finite state machines. A variety of models of computation was

Jie Liu; Xiaojun Liu; Edward A. Lee

2001-01-01

99

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

100

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.

101

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

102

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

103

Building a generalized distributed system model  

NASA Technical Reports Server (NTRS)

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

Mukkamala, Ravi

1991-01-01

104

Functional specialization in distributed operating systems  

Microsoft Academic Search

A distributed operating system provides the same functionality and interface as a monolithic operating system. That is, for both systems the goal is to make the computing and storage facilities as provided by the hardware available to the users of the system. In distributed operating system new hardware can be added to the system to increase the storage or computing

Robbert van Renesse; Andrew S. Tanenbaum; Gregory J. Sharp

1988-01-01

105

{open_quotes}Shift-Betel{close_quotes}: A (very) distributed mainframe  

SciTech Connect

Over the last four years, CERN has progressively converted its central batch production facilities from classic mainframe platforms (Cray XMP, IBM, ESA, Vax 9000) to distributed RISC based facilities, which have now attained a very large size. Both a CPU-intensive system ({open_quotes}CSF{close_quotes}, the Central Simulation Facility) and an I/O-intensive system ({open_quotes}SHIFT{close_quotes}, the Scaleable Heterogeneous Integrated Facility) have been developed, plus a distributed data management subsystem allowing seamless access to CERN`S central tape store and to large amounts of economical disk space. The full system is known as {open_quotes}CORE{close_quotes}, the Centrally Operated Risc Environment; at the time of writing CORE comprises around 2000 CERN Units of Computing (about 8000 MIPs) and over a TeraByte of online disk space. This distributed system is connected using standard networking technologies (IP protocols over Ethernet, FDDI and UltraNet), but which until quite recently were only implemented at sufficiently high speed in the Local Area.

Segal, B.; Martin, O.; Hassine, F.; Hemmer, F.; Jouanigot, J.M. [CERN, Geneva (Switzerland)

1994-12-31

106

OpenRIMS: an open architecture radiology informatics Management system.  

PubMed

The following are benefits of an integrated picture archiving and communication system/radiology information system archive built with open-source tools and methods: open source, inexpensive interfaces can be updated as needed, and reduced risk of redundant and inconsistent data. Also, wide adoption would promote standard data mining tools, reducing user needs to learn multiple methods to perform the same task. A model has been constructed capable of accepting orders, performing exam resource scheduling, providing Digital communications in Medicine (DICOM) work list information to modalities, archiving studies, and supporting DICOM query/retrieve from third-party viewing software. The multitiered architecture uses a single database communicating via an open database connectivity bridge to a Linux server with Health Level 7 (HL7), DICOM, and HTTP connections. Human interaction is supported via a browser, whereas other informatics systems communicate over the HL7 and DICOM links. The system is still under development, but the primary database schema is complete, as are key pieces of the Web user interface. Additional work is needed on the DICOM/HL7 interface broker and completion of the base DICOM service classes. PMID:12105742

Langer, Steve G

2002-01-01

107

An open laboratory automatic management system based on RFID  

Microsoft Academic Search

Open laboratories have great significance in university's education of science and technology, because it is difficult to manage open laboratories, basically many universities don't set up or seldom set up open laboratories. Combined with RFID technology, this paper discusses a kind of open laboratory management system suitable for electronic specialty. This system can realize open laboratory automatic management, doesn't need

Lu Ang; Fan Ying; Guan Zong qi

2010-01-01

108

The Planetary Data System Distributed Inventory System  

NASA Technical Reports Server (NTRS)

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

Hughes, J. Steven; McMahon, Susan K.

1996-01-01

109

Designing Distributed, Real-Time Systems  

E-print Network

- - Designing Distributed, Real-Time Systems Kevin L. Mills INFT 796 SUMMER 1993 DIRECTED READINGS IN SOFTWARE ENGINEERING WITH DR. H. GOMAA GEORGE MASON UNIVERSITY #12;Designing Distributed, Real-Time Systems problem faced by designers of software systems, and particularly by designers of distributed, real-time

Mills, Kevin

110

Control of Distributed Uninterruptible Power Supply Systems  

Microsoft Academic Search

In the last years, the use of distributed uninterruptible power supply (UPS) systems has been growing into the market, becoming an alternative to large conventional UPS systems. In addition, with the increasing interest in renewable energy integration and distributed generation, distributed UPS systems can be a suitable solution for storage energy in micro grids. This paper depicts the most important

Josep M. Guerrero; Lijun Hang; Javier Uceda

2008-01-01

111

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

112

Reliability Improvement Programs in Steam Distribution and Power Generation Systems  

E-print Network

Steam Group of failed open traps affecting Trap the differential pressures. Insufficient Heat Low differential pressure affecting Transfer the steam trap flow rate. Freezing Bottlenecks in the condensate system. Water Hammer Trap discharge over ~OF...REI:IABILITY IMPROVEMENT PROGRAMS IN STEAM DISTRIBUTION AND POWER GENERATION SYSTEMS Robert D. Atlas Tech/Serv Corporation Blue Bell, PA This paper will present alternatives to costly corrective maintenance repairs of the steam trap...

Atlas, R. D.

113

17 CFR 270.12b-1 - Distribution of shares by registered open-end management investment company.  

Code of Federal Regulations, 2011 CFR

...Distribution of shares by registered open-end management investment company. 270...Distribution of shares by registered open-end management investment company. (a...shall be unlawful for any registered open-end management investment company...

2011-04-01

114

17 CFR 270.12b-1 - Distribution of shares by registered open-end management investment company.  

Code of Federal Regulations, 2010 CFR

...Distribution of shares by registered open-end management investment company. 270...Distribution of shares by registered open-end management investment company. (a...shall be unlawful for any registered open-end management investment company...

2010-04-01

115

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

116

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

117

Providing reusability in distributed object control systems  

Microsoft Academic Search

Large scale, distributed industrial and scientific systems share many technical problems in the implementation of their control systems. Up to the present control system developers have had little opportunity of reusing software developed in one control system in the implementation of another. With the advent of standards in distributed object technology, it is now feasible to reuse control objects in

R. McClatchey; J.-M. Le Goff

1995-01-01

118

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

119

Middleware Architectures for Distributed Embedded Systems  

Microsoft Academic Search

A wide range of high-performance distributed embedded systems have been designed and deployed. Physically distributed embedded systems are used for manufacturing and control, traffic analysis, and other problems. Interestingly, today's systems-on-chips are sufficiently complex that they must be treated as distributed embedded systems. At all scales of physical extent, middleware is required to manage the computations. This paper looks at

Wayne Wolf

2008-01-01

120

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

2005-11-30

121

OpenRIMS: an open architecture radiology informatics management system.  

PubMed

The benefits of an integrated picture archiving and communication system/radiology information system (PACS/RIS) archive built with open source tools and methods are 2-fold. Open source permits an inexpensive development model where interfaces can be updated as needed, and the code is peer reviewed by many eyes (analogous to the scientific model). Integration of PACS/RIS functionality reduces the risk of inconsistent data by reducing interfaces among databases that contain largely redundant information. Also, wide adoption would promote standard data mining tools--reducing user needs to learn multiple methods to perform the same task. A model has been constructed capable of accepting HL7 orders, performing examination and resource scheduling, providing digital imaging and communications in medicine (DICOM) worklist information to modalities, archiving studies, and supporting DICOM query/retrieve from third party viewing software. The multitiered architecture uses a single database communicating via an ODBC bridge to a Linux server with HL7, DICOM, and HTTP connections. Human interaction is supported via a web browser, whereas automated informatics services communicate over the HL7 and DICOM links. The system is still under development, but the primary database schema is complete as well as key pieces of the web user interface. Additional work is needed on the DICOM/HL7 interface broker and completion of the base DICOM service classes. PMID:12297975

Langer, Steve

2002-06-01

122

Performance simulation of distributed energy management systems  

Microsoft Academic Search

The performance simulation of an open architecture energy management system (EMS) can provide detailed quantitative performance information long before a system is built. A method for simulating the performance of LAN-based EMSs is presented. The simulation shows how the performance of the system with respect to throughput and response time can be predicted. The results of the simulation of a

K. Kato; H. Rod Fudeh

1991-01-01

123

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

124

Continuously Diagonalized Density Operatorof Open Systems  

E-print Network

We showed several years ago that the density operator of Markovian open systems can be diagonalized continuously in time. The resulting pure state jump processes correspond to quantum trajectories proposed in recent quantum optics calculations or, at fundamental level, to exact consistent histories.

Lajos Diosi

1994-10-26

125

Open Source Course Management and Assessment System  

E-print Network

Cross-Institutional Resource Library Resource Assembly Course Management Resource Assembly Course-CAPA Architecture Shared Cross-Institutional Resource Library Resource Assembly Course Management Resource AssemblyLON-CAPA: Open Source Course Management and Assessment System Gerd Kortemeyer Michigan State

126

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.

127

Performance related issues in distributed database systems  

NASA Technical Reports Server (NTRS)

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

Mukkamala, Ravi

1991-01-01

128

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

129

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

130

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

131

A reliability assessment methodology for distribution systems with distributed generation  

E-print Network

be applied in preliminary planning studies for such systems. The method uses a sequential Monte Carlo simulation of the distribution systemÂ?s stochastic model to generate the operating behavior and combines that with a path augmenting Max flow algorithm...

Duttagupta, Suchismita Sujaya

2006-08-16

132

Understanding distributed control for energy management systems  

Microsoft Academic Search

Proposes that cost and reliability advantages can be realized by providing control and optimization functions at the local level while monitoring, alarming, reporting, and supervisory calculations are performed at a central location. Identifies this combination of local and central supervision as distributed control. Discusses low initial cost, geographic control distribution, functional control distribution, system comparisons, reliability and responsiveness, and cost

Manchon

1983-01-01

133

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

134

Distributed approximation of open-channel flow routing accounting for backwater effects  

E-print Network

Distributed approximation of open-channel flow routing accounting for backwater effects Simon on the channel dynamics. Key words: Open-channel flow routing, Saint-Venant equations, frequency response managers control flows in such open-channels using hydraulic structures (dams, weirs, gates). The water

Paris-Sud XI, Université de

135

An Open-Control Concept for a Holonic Multiagent System  

NASA Astrophysics Data System (ADS)

MAS are particularly adapted to deal with distributed and dynamic environment. The management of business workflow, or data flow, flexible manufacturing systems is typically a good application field for them. This kind of application requires centralization of the data control and flexibility to face with changes on the network. In the context of FMS, where products and resources entities can be seen as active, this paper presents the open-control concept and gives an example of its instantiation with holonic scheme. The open-control concept proposed in this paper exhibits the classic explicit control, as well as an innovative type of control called implicit control that allows system entities to be influenced via an Optimization Mechanism (OM). We illustrate our proposition by an implementation on a flexible assembly cell in our university.

Adam, Emmanuel; Berger, Thierry; Sallez, Yves; Trentesaux, Damien

136

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

137

Properties of adsorbates as open quantum systems  

NASA Astrophysics Data System (ADS)

We have recently developed a novel cluster-model approach to investigate adsorbate-surface systems. In our approach, a physically relevant subsystem is described as an open quantum system by considering a model cluster subject to the outgoing-wave boundary condition (OBC) at the edge of the cluster. We refer to this model as an open-boundary cluster model (OCM). Many known disadvantages of the conventional cluster-model approach, in which a model cluster is treated as an isolated system, have been remedied by introducing the OBC, whereas the local picture inherent in cluster models still remains valid. In our present research, the adsorption energy and the electron-transfer rate from adsorbates to surfaces are calculated with the OCM. Their dependences on the adsorption-distance and the Fermi energy are reasonably explained by analyzing the quasi-diabatic energy levels based on the local picture of adsorption.

Yasuike, Tomokazu; Nobusada, Katsuyuki

2008-10-01

138

Waves in Open Systems: Eigenfunction Expansions  

E-print Network

An open system is not conservative because energy can escape to the outside. An open system by itself is thus not conservative. As a result, the time-evolution operator is not hermitian in the usual sense and the eigenfunctions (factorized solutions in space and time) are no longer normal modes but quasinormal modes (QNMs) whose frequencies $\\omega$ are complex. QNM analysis has been a powerful tool for investigating open systems. Previous studies have been mostly system specific, and use a few QNMs to provide approximate descriptions. Here we review recent developments which aim at a unifying treatment. The formulation leads to a mathematical structure in close analogy to that in conservative, hermitian systems. Many of the mathematical tools for the latter can hence be transcribed. Emphasis is placed on those cases in which the QNMs form a complete set for outgoing wavefunctions, so that in principle all the QNMs together give an exact description of the dynamics. Applications to optics in microspheres and to gravitational waves from black holes are reviewed, and directions for further development are outlined.

E. S. C. Ching; P. T. Leung; W. M. Suen; S. S. Tong; K. Young

1999-04-06

139

Spectroscopic studies in open quantum systems  

E-print Network

The spectroscopic properties of an open quantum system are determined by the eigenvalues and eigenfunctions of an effective Hamiltonian H consisting of the Hamiltonian H_0 of the corresponding closed system and a non-Hermitian correction term W arising from the interaction via the continuum of decay channels. The eigenvalues E_R of H are complex. They are the poles of the S-matrix and provide both the energies and widths of the states. We illustrate the interplay between Re(H) and Im(H) by means of the different interference phenomena between two neighboured resonance states. Level repulsion along the real axis appears if the interaction is caused mainly by Re(H) while a bifurcation of the widths appears if the interaction occurs mainly due to Im(H). We then calculate the poles of the S-matrix and the corresponding wavefunctions for a rectangular microwave resonator with a scatter as a function of the area of the resonator as well as of the degree of opening to a guide. The calculations are performed by using the method of exterior complex scaling. Re(W) and Im(W) cause changes in the structure of the wavefunctions which are permanent, as a rule. At full opening to the lead, short-lived collective states are formed together with long-lived trapped states. The wavefunctions of the short-lived states at full opening to the lead are very different from those at small opening. The resonance picture obtained from the microwave resonator shows all the characteristic features known from the study of many-body systems in spite of the absence of two-body forces. The poles of the S-matrix determine the conductance of the resonator. Effects arising from the interplay between resonance trapping and level repulsion along the real axis are not involved in the statistical theory.

I. Rotter; E. Persson; K. Pichugin; P. Seba

2000-02-14

140

Steam generator feedwater distribution system  

SciTech Connect

A method for substantially uniformly mixing feedwater with recirculating water in a steam generator, having a shell, a wrapper, an annular down comer region positioned between said shell and said wrapper, an inlet nozzle, a tube bundle positioned within said wrapper and a distribution device, comprising the steps of: directing the flow of said feedwater from said inlet nozzle into said distribution device and circumferentially in both directions around at least a portion of aid annular down comer region; directing the flow of said feedwater uniformly distributed around said wrapper in an ascending direction in said distribution device toward a downwardly directing means of said distribution device; discharging said feedwater from said downwardly directing means into said down comer region; and mixing said feedwater exiting said downwardly directing means with descending recirculating water in said down comer region of said steam generator prior to entry of said feedwater into said tube bundle for providing a substantially uniform mixture of said feedwater and said recirculating water for reducing thermal shock and water hammer to said steam generator.

Wilson, R.M.; Chan, K.W.; Ford, D.E.

1993-05-25

141

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

142

Lighting system with heat distribution face plate  

DOEpatents

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

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

2013-09-10

143

Hybrid solar lighting distribution systems and components  

DOEpatents

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

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

2011-07-05

144

A Distributed Monitoring System For Power Quality  

Microsoft Academic Search

In the present paper, prototype architecture for a distributed system for online power quality parameters monitoring is illustrated. An interconnection between two different server types was performed. The remote processing and exchange of information on geographically distributed systems is a reality that becomes more and more integrating part of the technical and civil life. In this context the automation of

C. Donciu; C. Schreiner; M. Cretu; E. Lunca

145

Troubleshooting Distributed Systems via Data Mining  

Microsoft Academic Search

Through massive parallelism, distributed systems enable the multiplication of productivity. Unfortunately, increasing the scale of available machines to users will also multiply debugging when failure occurs. Data mining allows the extraction of patterns within large amounts of data and therefore forms the foundation for a useful method of debugging, particularly within such distributed systems. This paper outlines a successful application

David A. Cieslak; Douglas Thain; Nitesh V. Chawla

2006-01-01

146

Research into a distributed fault diagnosis system and its application  

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

147

Steam generator feedwater distribution system  

Microsoft Academic Search

A method for substantially uniformly mixing feedwater with recirculating water in a steam generator, having a shell, a wrapper, an annular down comer region positioned between said shell and said wrapper, an inlet nozzle, a tube bundle positioned within said wrapper and a distribution device, comprising the steps of: directing the flow of said feedwater from said inlet nozzle into

R. M. Wilson; K. W. Chan; D. E. Ford

1993-01-01

148

Shear flow pumping in open microfluidic systems  

E-print Network

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

Markus Rauscher; S. Dietrich; Joel Koplik

2006-10-26

149

Detecting data anomalies methods in distributed systems  

NASA Astrophysics Data System (ADS)

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

Mosiej, Lukasz

2009-06-01

150

Differences Between Distributed and Parallel Systems  

SciTech Connect

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

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

1998-10-01

151

Integration of fieldbus systems into distributed object-oriented systems  

Microsoft Academic Search

We describe an approach for integrating fieldbus systems into distributed object oriented systems. Integration of fieldbus systems into distributed object oriented systems means to treat the first one as an integral part of the last one. This integration has a methodological and a technical viewpoint. The first is related to the integration of models describing the application and its management,

P. Neumann; F. Iwanitz

1997-01-01

152

Impact of system security in an open market on nuclear power generating stations  

Microsoft Academic Search

In open market competition, the power industry will change from a vertically integrated and regulated monopoly to a functionally unbundled industry. The electric power system will split into separate disciplines namely generation, transmission, and distribution. The power producers can sell electricity directly to the consumers using the electric utility's transmission and distribution lines. The electric utilities are under great pressure

Narinder K. Trehan

2000-01-01

153

Human tracking using distributed vision systems  

Microsoft Academic Search

We present a wide area human tracking method using distributed computer vision systems. Each vision system consists of a camera and an image processor and they are all connected through a computer network. In this paper, we propose a method for human tracking and for coordination of all the vision systems. The human tracking method works on each vision system

Atsushi NAKAZAWA; Hirokazu KATO; Seiji INOKUCHI

1998-01-01

154

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

155

Measuring Advances in HVAC Distribution System Design  

SciTech Connect

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

Franconi, E.

1998-05-01

156

Open quantum systems and Dicke superradiance  

E-print Network

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.

Hichem Eleuch; Ingrid Rotter

2014-02-19

157

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

158

Development of an Integrated Distribution Management System  

SciTech Connect

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

Schatz, Joe E.

2010-10-20

159

Fluctuations of work in nearly adiabatically driven open quantum systems  

E-print Network

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

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

2014-11-18

160

A distributed building evacuation system  

E-print Network

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

Qumsiyeh, Dany M

2008-01-01

161

A Distributed Building Evacuation System  

E-print Network

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

Qumsiyeh, Dany M.

2008-07-14

162

Policy Provisioning for Distributed Identity Management Systems  

E-print Network

-grained access control for managing identity from security and privacy perspectives, they have not fullyPolicy Provisioning for Distributed Identity Management Systems Hidehito Gomi Yahoo! JAPAN Research framework is described that supports the management of the lifecycle of identity information distributed be

Boyer, Edmond

163

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...

164

Distributing Executive Information Systems through Networks.  

ERIC Educational Resources Information Center

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

Penrod, James I.; And Others

1993-01-01

165

Simulation-Based Testing of Distributed Systems  

Microsoft Academic Search

Developers of distributed systems routinely construct discrete-event simulations to help them un- derstand and evaluate the behavior of inter-component protocols. Typically written using an imperative programming language, these simulations capture basic algorithmic functionality at the same time as they focus attention on properties critical to distribution, including topology, timing, bandwidth, and overall scalability. We ask the following question: Can simulations

Matthew J. Rutherford; Antonio Carzaniga; Alexander L. Wolf

2006-01-01

166

Multicommodity Distribution System Design by Benders Decomposition  

Microsoft Academic Search

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

A. M. Geoffrion; G. W. Graves

1974-01-01

167

Network design consideration for distributed control systems  

Microsoft Academic Search

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

Feng-Li Lian; James Moyne; Dawn Tilbury

2002-01-01

168

Urban water supply distributed control system  

Microsoft Academic Search

The rapid growing of the wide urban residential areas imposes the expansion as well as the modernization of the existing water supply facilities. Process automation system based upon utilization of an industrial PLC and PC systems including all the network components represents the best way to improve the water distribution technological process. The system includes remote terminal units - RTU,

E. Stancel; I. Stoian; I. Kovacs; B. Z. Gyurka; S. Balogh

2008-01-01

169

A Distributed System for Cooperative MIMO Transmissions  

E-print Network

a distributed system for facilitating cooperative MIMO transmissions in networks without multiple antenna. At the physical layer, MIMO systems use multiple antennas to achieve spatial diversity. However, MIMO systems require multi-antennas devices, which may not be feasible in some devices due to cost and size limitations

Kalyanaraman, Shivkumar

170

Managing Distributed Systems with Smart Subscriptions  

E-print Network

Managing Distributed Systems with Smart Subscriptions Robert E. Filman Diana D. Lee Research on using "smart subscriptions" to recognize weakly structured events. We present a hierarchy paths between components. By injecting the behavior for error recovery, behavior for error recovery

Filman, Robert E.

171

Distributed-data imaging system  

SciTech Connect

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

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

1996-05-01

172

Concurrency control in heterogeneous distributed database systems  

E-print Network

CONCURRENCY CONTROL IN HETEROGENEOUS DISTRIBUTED DATABASE SYSTEMS A Thesis by MD. REZAUR RAHMAN Subnritted to the Office of Graduate Studies of Texas ARM University in partial fulfilln&ent of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Computer Science CONCURRENCY CONTROL IN HETEROGENEOUS DISTRIBUTED DATABASE SYSTEMS A Thesis by MD. REZAUR RAHMAN Approved as to style and content by: unguk L. Kim (Co-Chair of Committee) J. C. Liu (Co...

Rahman, Md. Rezaur

2012-06-07

173

DCBITS: Distributed Case Base Intelligent Tutoring System  

NASA Astrophysics Data System (ADS)

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

Rishi, O. P.; Govil, Rekha

2008-05-01

174

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

175

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

176

Analysis of Task Assignment Policies in Scalable Distributed Web-Server Systems  

Microsoft Academic Search

A distributed multi-server Web site can provide the scalability necessary to keep up with growing client demand at popular sites. Load balancing of these distributed Web-server systems, consisting of multiple Web servers for document retrieval and a Domain name server (DNS) for address resolution, opens interesting new problems. In this paper, we investigate the effects of using a more active

Michele Colajanni; Philip S. Yu; Daniel M. Dias

1998-01-01

177

Lightning protection of distribution systems. Final report  

SciTech Connect

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

Uman, M.A.

1985-02-01

178

Studying distribution system reliability against lightning  

SciTech Connect

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

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

1989-01-01

179

Support for User Interfaces for Distributed Systems  

NASA Technical Reports Server (NTRS)

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

Eychaner, Glenn; Niessner, Albert

2005-01-01

180

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

181

Variational functions in driven open quantum systems  

SciTech Connect

We consider the Lindblad-type master equation of an open system. We address the question how to construct a functional of the quantum state which displays a monotonic behavior in time. This thus defines uniquely the direction of time in the system. As the generator of time evolution is not a Hermitian operator, the theory requires the considerations of right and left eigenstates. In this paper we assume them to form two complete bases, which allows us to construct the desired quantity. This can be interpreted as a generalized entropy functional. We show how the construction is carried out in the general case, and we illustrate the theory by solving the case of an externally driven and damped two-level system. The treatment is related to earlier work in the field, and its possible relation to time inversion is discussed.

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

2003-03-01

182

Integrating CLIPS applications into heterogeneous distributed systems  

NASA Technical Reports Server (NTRS)

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

Adler, Richard M.

1991-01-01

183

Distributed Access View Integrated Database (DAVID) system  

NASA Technical Reports Server (NTRS)

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

Jacobs, Barry E.

1991-01-01

184

DIstributed VIRtual System (DIVIRS) Project  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

185

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

Microsoft Academic Search

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

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

2010-01-01

186

Revise CS 552: Distributed Systems to CS552: Distributed Real-Time Systems  

E-print Network

-to-end design of real-time systems 2 Main material is from Allen Burns' book 3 From Formal methods for real-timeRevise CS 552: Distributed Systems to CS552: Distributed Real-Time Systems Course Description As the advance of computer hardware, embedded devices, and network tech- nology, real-time applications have

Heller, Barbara

187

Performance Monitoring of Distributed Data Processing Systems  

NASA Technical Reports Server (NTRS)

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

Ojha, Anand K.

2000-01-01

188

A Distributed Heterogeneous Supercomputing Management System  

Microsoft Academic Search

A general management framework for distributed heterogenous supercomputing systems (DHSSs) that is based on an application-characterization technique is presented. The technique uses code profiling and analytical benchmarking of supercomputers. An optimal scheduling of tasks in these systems is an NP-complete problem. The use of network caching to reduce the complexity associated with the scheduling decisions is discussed. An experimental prototype

Arif Ghafoor; Jaehyung Yang

1993-01-01

189

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

190

Real-time distributed multimedia systems  

SciTech Connect

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

Rahurkar, S.S.; Bourbakis, N.G. [Binghamton Univ., NY (United States)

1996-12-31

191

Expert System Detects Power-Distribution Faults  

NASA Technical Reports Server (NTRS)

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

Walters, Jerry L.; Quinn, Todd M.

1994-01-01

192

On the Choice of Insurance Distribution Systems  

Microsoft Academic Search

We examine insurers' choice between independent and exclusive agents. We assume that alternative distribution systems are efficient mechanisms for controlling contracting problems among policyholders, insurers, and agents. Because the use of independent agents helps control potential expropriative behavior by the insurer, the independent agency system should be more valuable for ownership structures where such problems are more severe. Thus, ownership

K. W. Joong; David Mayers; Clifford W. Smith

1996-01-01

193

GRAMS: a distributed multimedia service system  

NASA Astrophysics Data System (ADS)

This paper is on the design and implementation of GRAMS (Gopher-style Real-time ATM Multimedia Services), a multimedia system designed for a star configuration ATM LAN with the central server providing multimedia services to multiple users in real-time. It is also the initial step towards and the essential part of a distributed multimedia system over larger area networks.

Hui, Joseph Y.; Zhang, Junbiao

1994-04-01

194

Wireless network emulation for distributed processing systems  

Microsoft Academic Search

A formidable challenge for laboratory integration and testing of a wireless distributed processing system is establishing a representative wireless network for data communications. Realistic network performance is particularly necessary when system operation is sensitive to the throughput, delay, and reliability characteristics of a low-bandwidth ad hoc network. When the processing node data interfaces are actually radios with embedded networking protocols,

Robert J. Wellington; M. D. Kubischta

2003-01-01

195

Distilled Water Distribution Systems. Laboratory Design Notes.  

ERIC Educational Resources Information Center

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

Sell, J.C.

196

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

197

Data Integration in Computer Distributed Systems  

NASA Astrophysics Data System (ADS)

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

Kwiecie?, B?a?ej

198

Distributed algorithms for monitoring and control of electric power transmission and distribution systems  

Microsoft Academic Search

The benefits of distributed computing systems are massively increased computing power and improved reliability. Distributed computing systems are particularly attractive for monitoring and control of large-scale electric power transmission and distribution systems. In this dissertation two aspects of distributed computing have been investigated. First, a distributed software model for the implementation of network security functions in energy management systems is

Neyer

1989-01-01

199

Onsite Wastewater Treatment Systems: Spray Distribution System  

E-print Network

it is sprayed onto the soil surface. How- ever, state regulations require that each system be designed to handle the most amount of wastewater expected from that household or business, and to be able to handle it during the Bruce Lesikar Professor...

Lesikar, Bruce J.

2008-10-23

200

Open, reconfigurable cytometric acquisition system: ORCAS.  

PubMed

A digital signal processing (DSP)-based digital data acquisition system has been developed to support novel flow cytometry efforts. The system flexibility includes how it detects, captures, and processes event data. Custom data capture boards utilizing analog to digital converters (ADCs) and field programmable gate arrays (FPGA) detect events and capture correlated event data. A commercial DSP board processes the captured data and sends the results over the IEEE 1394 bus to the host computer that provides a user interface for acquisition, display, analysis, and storage. The system collects list mode data, correlated pulse shapes, or streaming data from a variety of detector types using Linux, Mac OS X, and Windows host computers. It extracts pulse features not found on commercial systems with excellent sensitivity and linearity over a wide dynamic range. List mode data are saved in FCS 3.0 formatted files while streaming or correlated waveform data are saved in custom format files for postprocessing. Open, reconfigurable cytometric acquisition system is compact, scaleable, flexible, and modular. Programmable feature extraction algorithms have exciting possibilities for both new and existing applications. The recent availability of a commercial data capture board will enable general availability of similar systems. PMID:17680705

Naivar, Mark A; Parson, Jimmie D; Wilder, Mark E; Habbersett, Robert C; Edwards, Bruce S; Sklar, Larry; Nolan, John P; Graves, Steven W; Martin, John C; Jett, James H; Freyer, James P

2007-11-01

201

Disentanglement and decoherence by open system dynamics  

NASA Astrophysics Data System (ADS)

The destruction of quantum interference, decoherence, and the destruction of entanglement both appear to occur under the same circumstances. To address the connection between these two phenomena, we consider the evolution of arbitrary initial states of a two-particle system under open system dynamics described by a class of master equations which produce decoherence of each particle. We show that all initial states become separable after a finite time, and we produce the explicit form of the separated state. The result extends and amplifies an earlier result of Diósi. We illustrate the general result by considering the case in which the initial state is an Einstein-Podolsky-Rosen state (in which both the positions and momenta of a particle pair are perfectly correlated). This example clearly illustrates how the spreading out in phase space produced by the environment leads to certain disentanglement conditions becoming satisfied.

Dodd, P. J.; Halliwell, J. J.

2004-05-01

202

Disentanglement and decoherence by open system dynamics  

SciTech Connect

The destruction of quantum interference, decoherence, and the destruction of entanglement both appear to occur under the same circumstances. To address the connection between these two phenomena, we consider the evolution of arbitrary initial states of a two-particle system under open system dynamics described by a class of master equations which produce decoherence of each particle. We show that all initial states become separable after a finite time, and we produce the explicit form of the separated state. The result extends and amplifies an earlier result of Diosi. We illustrate the general result by considering the case in which the initial state is an Einstein-Podolsky-Rosen state (in which both the positions and momenta of a particle pair are perfectly correlated). This example clearly illustrates how the spreading out in phase space produced by the environment leads to certain disentanglement conditions becoming satisfied.

Dodd, P.J.; Halliwell, J.J. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

2004-05-01

203

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

204

Energy optimization of water distribution system  

SciTech Connect

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

Not Available

1993-02-01

205

Dynamics of open systems governed by the Milburn equation  

NASA Astrophysics Data System (ADS)

Within the framework of the Milburn model of intrinsic decoherence [G. J. Milburn, Phys. Rev. A 44, 5401 (1991)], which is based on an assumption of an existence of the fundamental time step, we study the dynamics of open systems. We show that evolution of an open system governed by the Milburn equation can be significantly modified compared to the standard Schrödinger quantum mechanics. This modification is most pronounced when an open system is strongly coupled to its environment.

Bužek, V.; Konôpka, M.

1998-09-01

206

Distributed microcomputer control system for advanced teleoperation  

Microsoft Academic Search

A modular and expandable distributed microcomputer hardware and software system is described matching the natural needs of real-time mechanization of manipulator control in space teleoperation. The natural needs include: (a) distribution of real-time control computing power between control station and remote robot arms equipped with smart end effectors and (b) the use of interchangeable control techniques like (i) generalized force-reflecting

C. P. Fong; R. S. Dotson; A. K. Bejczy

1986-01-01

207

A system for distributed intrusion detection  

Microsoft Academic Search

The network intrusion-detection concept is extended from the LAN (local area network) environment to arbitrarily wider areas, with the network topology being arbitrary as well. The generalized distributed environment is heterogeneous, i.e. the network nodes can be hosts or servers from different vendors, or some of them could be LAN managers. The proposed architecture for this distributed intrusion-detection system consists

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

1991-01-01

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

Optical Clock Distribution in Electronic Systems  

Microsoft Academic Search

Techniques for distribution of optical signals, both free space and guided, within electronic systems has been extensively investigated over more than a decade. Particularly at the lower levels of packaging (intra- chip and chip-to-chip), miniaturized optical elements including difiractive optics and micro-refractive optics have received considerable attention. In the case of optical distribution of data, there is the need for

Stuart K. Tewksbury; Lawrence A. Hornak

1997-01-01

210

46 CFR 28.855 - Electrical distribution systems.  

...2014-10-01 2014-10-01 false Electrical distribution systems. 28.855 Section...Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a...

2014-10-01

211

46 CFR 28.855 - Electrical distribution systems.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Electrical distribution systems. 28.855 Section...Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a...

2013-10-01

212

46 CFR 28.855 - Electrical distribution systems.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Electrical distribution systems. 28.855 Section...Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a...

2012-10-01

213

46 CFR 28.855 - Electrical distribution systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Electrical distribution systems. 28.855 Section...Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a...

2010-10-01

214

46 CFR 28.855 - Electrical distribution systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Electrical distribution systems. 28.855 Section...Aleutian Trade Act Vessels § 28.855 Electrical distribution systems. (a) Each electrical distribution system which has a...

2011-10-01

215

46 CFR 28.360 - Electrical distribution systems.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Electrical distribution systems. 28.360 Section...16 Individuals on Board § 28.360 Electrical distribution systems. (a) Each electrical distribution system which has a...

2013-10-01

216

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

217

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

218

Distributed Filtering and Estimation for Industrial Systems  

Microsoft Academic Search

\\u000a Distributed Filtering and estimation methods for industrial systems are studied. Such methods are particularly useful in case\\u000a that measurements about the industrial system are collected and processed by n different monitoring stations. The overall concept is that at each monitoring station a filter is used to track the state\\u000a of the system by fusing measurements which are provided by various

Gerasimos G. Rigatos

219

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

220

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

221

An Open-Source Learning Content Management and Assessment System  

E-print Network

-CAPA Architecture Shared Cross-Institutional Resource Library Resource Assembly Course Management Resource AssemblyLON-CAPA An Open-Source Learning Content Management and Assessment System Gerd Kortemeyer-CAPA is free open-source a learning content management system an assessment system around since 1992 #12

222

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

223

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

224

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

225

PHOSPHORUS IN ALUM AMENDED POULTRY LITTER SYSTEMS: DISTRIBUTION, SPECIATION, AND  

E-print Network

PHOSPHORUS IN ALUM AMENDED POULTRY LITTER SYSTEMS: DISTRIBUTION, SPECIATION, AND INTERACTIONS;PHOSPHORUS IN ALUM AMENDED POULTRY LITTER SYSTEMS: DISTRIBUTION, SPECIATION, AND INTERACTIONS WITH ALUMINUM

Sparks, Donald L.

226

Relativistic Quantum Metrology in Open System Dynamics  

E-print Network

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

Tian, Zehua; Fan, Heng; Jing, Jiliang

2015-01-01

227

A Distributed Architecture for Norm Management in Multi-Agent Systems  

Microsoft Academic Search

Abstract. Norms, that is, obligations, prohibitions and permissions, are useful abstractions to facilitate coordination in open, heterogeneous multi-agent systems. We observe a lack of distributed architectures and non-centralised computational models for norms. We propose a model, viz., normative structures, to regulate the behaviour of autonomous agents taking part in simultaneous and possibly related activities within a multi- agent system. This

Andrés García-camino; Juan A. Rodríguez-aguilar; Wamberto Weber Vasconcelos

2007-01-01

228

A Distributed Architecture for Norm Management in Multi-Agent Systems  

Microsoft Academic Search

Norms, that is, obligations, prohibitions and permissions, are useful abstractions to facilitate coordination in open, heterogeneous multi-agent systems. We observe a lack of distributed architectures and non-centralised computational models for norms. We propose a model, viz., normative structures, to regulate the behaviour of autonomous agents taking part in simultaneous and possibly related activities within a multi- agent system. This artifact

A. Garc; J. A. Rodr guez-Aguilar; W. Vasconcelos

229

High temperature hot water distribution system study  

SciTech Connect

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

NONE

1996-12-01

230

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

231

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

232

Deceit: A flexible distributed file system  

NASA Technical Reports Server (NTRS)

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

Siegel, Alex; Birman, Kenneth; Marzullo, Keith

1989-01-01

233

STABILITY CONDITIONS FOR SOME DISTRIBUTED SYSTEMS: BUFFERED RANDOM ACCESS SYSTEMS  

E-print Network

STABILITY CONDITIONS FOR SOME DISTRIBUTED SYSTEMS: BUFFERED RANDOM ACCESS SYSTEMS August 18, 1993.S.A. Abstract We consider the standard slotted ALOHA system with a finite number of buffered users. Stability on the stability region have been established, however, the exact stability region is known only for the symmetric

Szpankowski, Wojciech

234

Distributed Neural Systems for Face Perception  

E-print Network

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

Bucci, David J.

235

Biofilm accumulation in drinking water distribution systems  

Microsoft Academic Search

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

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

1993-01-01

236

Harmonic analysis of electrical distribution systems  

SciTech Connect

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

NONE

1996-03-01

237

Optimal capacitor placement on radial distribution systems  

Microsoft Academic Search

Capacitor placement problem on radial distribution systems is formulated and a solution algorithm is proposed. The location, type, and size of capacitors, voltage constraints, and load variations are considered in the problem. The objective of capacitor placement is peak power and energy loss reduction by raking into account the cost of capacitors. The problem is formulated as a mixed integer

M. E. Baran; F. F. Wu

1989-01-01

238

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

239

Network Coding for Distributed Storage Systems  

Microsoft Academic Search

Peer-to-peer distributed storage systems pro- vide reliable access to data through redundancy spread over nodes across the Internet. A key goal is to minimize the amount of bandwidth used to maintain that redundancy. Storing a file using an erasure code, in fragments spread across nodes, promises to require less redundancy and hence less maintenance bandwidth than simple replication to provide

Alexandros G. Dimakis; Brighten Godfrey; Martin J. Wainwright; Kannan Ramchandran

2007-01-01

240

Distributed expert systems for network performance optimization  

Microsoft Academic Search

A distributed expert system that uses a simulation-based optimization methodology for queuing networks and whose architecture permits parallel simulation of multiple configurations is presented. A knowledge-based search that is a randomized combination of steepest descent and branch and bound algorithms in which the generating function of new states uses qualitative reasoning and the gradient of the objective function is estimated

YUVAL LIROV; BENJAMIN MELAMED

1990-01-01

241

ITMOC ITO.012 Session 6: Distributed Systems  

E-print Network

even heard of crashes [Lamport] A distributed system is one in which hardware or software components Aircraft industry Additional processing units are used for specific needs (data logging, cockpit displays for instance) Peer-to-Peer (P2P) file sharing networks Each user contributes to the network Auto

Cheverst, Keith

242

COST FOR WATER SUPPLY DISTRIBUTION SYSTEM REHABILITATION  

EPA Science Inventory

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

243

Experience with the Condor distributed batch system  

Microsoft Academic Search

Condor is a distributed batch system designed to provide convenient access to unutilized workstations while preserving the rights of their owners and to meet the needs of users who are frustrated by the limitations of computing on a single workstation. Several principles have driven the design of Condor. The first is that workstation owners should always have the resources of

M. Litzkow; M. Livny

1990-01-01

244

DOT: A New Distributed Data Management System  

Microsoft Academic Search

In this paper we have proposed a new distributed data management system (DDMS) called DOT which provides high performance in an environment of high data mobility and heterogeneous host capabilities. The storage sites of DOT are divided in some groups where a group of client sites is under an administrator site. Intra group and inter group communications in DOT are

A. Akther; K. S. N. Ripon; K. M. Alam

2007-01-01

245

Ray tracing on distributed memory parallel systems  

NASA Technical Reports Server (NTRS)

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

Jensen, David W.; Reed, Daniel A.

1990-01-01

246

A Distributed Operating System for the IWOs  

E-print Network

Amoeba A Distributed Operating System for the IWOs Sape J. Mullender and Guido van Rossum Centre programs take advantage of multiple CPUs, even when all The Amoeba puter Science in Amsterdam. Amoeba hard to achieve extremely high performance: Amoeba is already one speed, fault tolerance

Tanenbaum, Andrew S.

247

Experiences with the Amoeba Distributed Operating System  

E-print Network

Experiences with the Amoeba Distributed Operating System Andrew S. Tanenbaum Robbert van Renesse 1 Kruislaan 413 1098 SJ Amsterdam, The Netherlands Internet: sape@cwi.nl, jack@cwi.nl, guido@cwi.nl The Amoeba.W.O.) under grant 125-30-10. #12;INTRODUCTION The Amoeba project is a research effort aimed at understanding

Tanenbaum, Andrew S.

248

The non-Markovian stochastic Schrödinger equation for open systems  

Microsoft Academic Search

We present the non-Markovian generalisation of the widely used stochastic Schrödinger equation. Our result allows one to describe open quantum systems in terms of stochastic state vectors rather than density operators, without Markov approximation. Moreover, it unifies two recent independent attempts towards a stochastic description of non-Markovian open systems, based on path integrals on the one hand and coherent states

Lajos Diósi; Walter T. Strunz

1997-01-01

249

The non-Markovian stochastic Schrodinger equation for open systems  

Microsoft Academic Search

We present the non-Markovian generalization of the widely used stochastic Schrodinger equation. Our result allows to describe open quantum systems in terms of stochastic state vectors rather than density operators, without Markov approximation. Moreover, it unifies two recent independent attempts towards a stochastic description of non-Markovian open systems, based on path integrals on the one hand and coherent states on

Lajos Diosi; Walter T. Strunz

250

GamingAnywhere--The First Open Source Cloud Gaming System  

E-print Network

1 GamingAnywhere--The First Open Source Cloud Gaming System CHUN-YING HUANG, National Taiwan Ocean source cloud gaming system, called GamingAnywhere. In addition to its openness, we design Gaming by the researchers, game developers, service providers, and end users for setting up cloud gaming testbeds, which, we

Chen, Sheng-Wei

251

Empowering open systems through cross-platform interoperability  

NASA Astrophysics Data System (ADS)

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

Lyke, James C.

2014-06-01

252

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

253

Microcanonical origin of the maximum entropy principle for open systems.  

PubMed

There are two distinct approaches for deriving the canonical ensemble. The canonical ensemble either follows as a special limit of the microcanonical ensemble or alternatively follows from the maximum entropy principle. We show the equivalence of these two approaches by applying the maximum entropy formulation to a closed universe consisting of an open system plus bath. We show that the target function for deriving the canonical distribution emerges as a natural consequence of partial maximization of the entropy over the bath degrees of freedom alone. By extending this mathematical formalism to dynamical paths rather than equilibrium ensembles, the result provides an alternative justification for the principle of path entropy maximization as well. PMID:23214548

Lee, Julian; Pressé, Steve

2012-10-01

254

PILOT: An intelligent distributed operations support system  

NASA Technical Reports Server (NTRS)

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

Rasmussen, Arthur N.

1993-01-01

255

Data distribution satellite system architecture concept  

NASA Technical Reports Server (NTRS)

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

Price, Kent M.; Jorasch, Ronald E.

1990-01-01

256

Stabilized fiber-optic frequency distribution system  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

257

RESEARCH Open Access Fractional order polytopic systems: robust  

E-print Network

RESEARCH Open Access Fractional order polytopic systems: robust stability and stabilisation of commensurate fractional order polytopic systems (FOS). In the proposed approach, Linear Matrix Inequalities of a fractional order such that 0

Paris-Sud XI, Université de

258

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

259

Proceedings: Transmission and distribution automation systems  

SciTech Connect

The EPRI-sponsored seminar on Transmission and Distribution Automation provided the participants with information on the conception, development and design, and implementation of systems employing digital technology and fiber optics for integrated system for protection, control, monitoring, and communication in substations. Eighty engineers from utilities, suppliers, and consultants attended the seminar. Twenty-five papers were presented and discussed at the seminar. Demonstrations of developed equipment were held at the seminar site and at two host utilities where transmission substation automation systems have been installed. Each report will be automated individually.

Not Available

1990-03-01

260

Distributed parallel messaging for multiprocessor systems  

DOEpatents

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

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

2013-06-04

261

Customers' Interaction in Super Distributed Energy Systems  

NASA Astrophysics Data System (ADS)

This paper deals with numerical analysis of behaviors for cooperative and competitive systems operated in the super distributed environment. Since the behavior is dictated by a complicated interaction of electric power outputs produced by numerous dispersed generators, the study is focused on the macroscopic behavior as well as the microscopic behavior of numerous dispersed generators based on the stability analysis of the Hopfield neural network. Some simulation results using a typical energy system model make it clear that maintenance of supply-and-demand balance becomes difficult when customers with a dispersed generation system cannot obtain sufficient information from their neighborhood.

Ishii, Tsunayoshi; Yasuda, Keiichiro

262

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

E-print Network

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

deYoung, Brad

263

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

264

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

265

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

266

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

267

Web services for distributed and interoperable hydro-information systems  

NASA Astrophysics Data System (ADS)

Web services support the integration and interoperability of Web-based applications and enable machine-to-machine interaction. The concepts of web services and open distributed architecture were applied to the development of T-DSS, the prototype customised for web based hydro-information systems. T-DSS provides mapping services, database related services and access to remote components, with special emphasis placed on output flexibility (e.g. multilingualism), where SOAP web services are mainly used for communication. The remote components are represented above all by distant data and mapping services (e.g. eteorological predictions), modelling and analytical systems (currently HEC-HMS, Modflow and additional utilities), which support decision making in water management.

Horak, J.; Orlik, A.; Stromsky, J.

2007-06-01

268

Web services for distributed and interoperable hydro-information systems  

NASA Astrophysics Data System (ADS)

Web services support the integration and interoperability of Web-based applications and enable machine-to-machine interaction. The concepts of web services and open distributed architecture were applied to the development of T-DSS, the prototype customised for web based hydro-information systems. T-DSS provides mapping services, database related services and access to remote components, with special emphasis placed on the output flexibility (e.g. multilingualism), where SOAP web services are mainly used for communication. The remote components are represented above all by remote data and mapping services (e.g. meteorological predictions), modelling and analytical systems (currently HEC-HMS, MODFLOW and additional utilities), which support decision making in water management.

Horak, J.; Orlik, A.; Stromsky, J.

2008-03-01

269

Lightning protection of distribution systems. Final report  

SciTech Connect

Research work on the lightning protection of distribution systems is described. The rationale behind the planning of the first major phase of the work - the field experiments conducted in the Tampa Bay area during August 1978 and July to September 1979 is explained. The aims of the field work were to characterize lightning in the Tampa Bay area, and to identify the lightning parameters associated with the occurrence of line outages and equipment damage on the distribution systems of the participating utilities. The equipment developed for these studies is fully described. The field work provided: general data on lightning - e.g., electric and magnetic fields of cloud and ground flashes; data from automated monitoring of lightning activity; stroke current waveshapes and peak currents measured at distribution arresters; and line outage and equipment damage on 13 kV networks in the Tampa Bay area. Computer aided analyses were required to collate and to process the accumulated data. The computer programs developed for this work are described. Improved models of the lightning ground flash were developed and incorporated into improved analytical methods for calculating the response of distribution system to overvoltages produced by direct strokes and by induction from nearby strokes. The development of the following are described: an improved model of the leader, and its incorporation into the electrogeometric method for determining the point of contact at ground level; a more detailed model of the lightning ground flash, and its incorporation into a computer program for calculating line outage rates due to direct lightning strikes; and a multi-conductor travelling wave technique for calculating voltage and current surges on the phase conductor and the neutral of an unshielded distribution line subject to a direct lightning strike.

Darveniza, M.; Uman, M.A.

1982-09-01

270

Reliability evaluation of distribution system with distributed generation based on Islanding algorithm  

Microsoft Academic Search

Distributed generation (DG), which is interlinked with distribution system, will inevitably have an impact to system. In the paper, a reliability evaluation method is proposed, which is based on the analysis to the structure and power flow of distribution system with distributed generation. First, a new concept, the smallest unit, is put forward for improving the fault traversal networks times.

Guoquan Wang; Zongqi Liu; Nian Liu; Jianhua Zhang

2008-01-01

271

Open process and open-source enterprise systems  

Microsoft Academic Search

Enterprise systems have become pervasive, especially at the high end of the market where SAP and Oracle service large organisations. There is a great deal of value in enterprise systems offered to all organisations, but many small and medium businesses (SMBs) cannot afford the excessive software costs of established ERP systems. There have been a number of alternative forms of

Sang M. Lee; David L. Olson; Sang-Heui Lee

2009-01-01

272

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

273

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

274

Power Distribution System Planning with GIS Consideration  

NASA Astrophysics Data System (ADS)

This paper proposes a method for solving radial distribution system planning problems taking into account geographical information. The proposed method can automatically determine appropriate location and size of a substation, routing of feeders, and sizes of conductors while satisfying all constraints, i.e. technical constraints (voltage drop and thermal limit) and geographical constraints (obstacle, existing infrastructure, and high-cost passages). Sequential quadratic programming (SQP) and minimum path algorithm (MPA) are applied to solve the planning problem based on net price value (NPV) consideration. In addition this method integrates planner's experience and optimization process to achieve an appropriate practical solution. The proposed method has been tested with an actual distribution system, from which the results indicate that it can provide satisfactory plans.

Wattanasophon, Sirichai; Eua-Arporn, Bundhit

275

Distributed optically integrated manufacture system based on CORBA  

NASA Astrophysics Data System (ADS)

Focused on the shortcoming and insufficiency of reconfigurable manufacture system (RMS) for optical manufacturing in control layer and interface of manufacturing execution systems (MES) and control layer, the difference of MES-plan layer interface and that of MES-control layer is discussed, and an architecture of distributed optically integrated manufacture executing system based on fieldbus/Ethernet network and common object request broker architecture (CORBA) is presented. In this solution, the optical manufacture equipments are connected by fieldbus network, a gateway is used for the communication of fieldbus manufacture equipment and MES in the workshop, and CORBA services which provide a general interface for communication of heterogeneous fieldbus manufacture equipment of workshop are realized on the gateway. Then all specifics of heterogeneous fieldbus manufacture equipments are concealed, which show as virtual equipment and can be accessed in a simple and unified way. So the control layer is composed of virtual equipment and easy to be reconfigured. Similarly workshop management function components are modeled and encapsulated by CORBA interface, and MES could be integrated to RMS expediently. The optical integrated manufacture system presented is proved with good ability of flexible, reconfigurable, opening and high feasibility, and met the reconfigurable requirement of distributed optical manufacturing workshop preferably.

Cen, Ming; Jiang, Jian-chun; Liu, Xing-fa; Hu, Rui-fei

2007-12-01

276

Relativistic Quantum Metrology in Open System Dynamics  

E-print Network

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

Zehua Tian; Jieci Wang; Heng Fan; Jiliang Jing

2015-01-27

277

Relativistic Quantum Metrology in Open System Dynamics  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

278

Relativistic Quantum Metrology in Open System Dynamics  

PubMed Central

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

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

2015-01-01

279

Relativistic quantum metrology in open system dynamics.  

PubMed

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

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

2015-01-01

280

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

281

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

Code of Federal Regulations, 2011 CFR

...what the open video system operator, or its affiliate...is applicable to a new market entrant (the open video system operator) that will...but not limited to payments for programming and...2) An open video system operator can...

2011-10-01

282

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

Code of Federal Regulations, 2013 CFR

...what the open video system operator, or its affiliate...is applicable to a new market entrant (the open video system operator) that will...but not limited to payments for programming and...2) An open video system operator can...

2013-10-01

283

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

Code of Federal Regulations, 2010 CFR

...what the open video system operator, or its affiliate...is applicable to a new market entrant (the open video system operator) that will...but not limited to payments for programming and...2) An open video system operator can...

2010-10-01

284

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

Code of Federal Regulations, 2012 CFR

...what the open video system operator, or its affiliate...is applicable to a new market entrant (the open video system operator) that will...but not limited to payments for programming and...2) An open video system operator can...

2012-10-01

285

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

...building and maintaining the open video system. Contained in...of each component. When an open video system operator provides...the programming and packaging flows from the independent program provider, who bears the cost. The open video system operator...

2014-10-01

286

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)

1987-01-01

287

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

288

Distributed Power Electronics for PV Systems (Presentation)  

SciTech Connect

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

Deline, C.

2011-12-01

289

Performance Estimation for Real-Time Distributed Embedded Systems  

Microsoft Academic Search

Many embedded computing systems are distributed systems: communicating processes executing on several CPUs\\/ASICs. This paper describes a performance analysis algorithm for a set of tasks executing on a heterogeneous distributed system. Tight bounds are essential to the synthesis and verification of application-specific distributed systems, such as embedded computing systems. Our bounding algorithms are valid for a general problem model: The

Ti-yen Yen; Wayne Wolf

1998-01-01

290

Quantifying entanglement in multipartite conditional states of open quantum systems by measurements of their photonic environment  

E-print Network

A key lesson of the decoherence program is that information flowing out from an open system is stored in the quantum state of the surroundings. Simultaneously, quantum measurement theory shows that the evolution of any open system when its environment is measured is nonlinear and leads to pure states conditioned on the measurement record. Here we report the discovery of a fundamental relation between measurement and entanglement which is characteristic of this scenario. It takes the form of a scaling law between the amount of entanglement in the conditional state of the system and the probabilities of the experimental outcomes obtained from measuring the state of the environment. Using the scaling, we construct the distribution of entanglement over the ensemble of experimental outcomes for standard models with one open channel and provide rigorous results on finite-time disentanglement in systems coupled to non-Markovian baths. The scaling allows the direct experimental detection and quantification of entangl...

Urbina, Juan Diego; Viviescas, Carlos

2012-01-01

291

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

Code of Federal Regulations, 2010 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral of each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2010-10-01

292

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

Code of Federal Regulations, 2011 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral of each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2011-10-01

293

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

Code of Federal Regulations, 2010 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral or each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2010-10-01

294

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

Code of Federal Regulations, 2013 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral of each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2013-10-01

295

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

Code of Federal Regulations, 2012 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral of each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2012-10-01

296

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

Code of Federal Regulations, 2013 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral or each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2013-10-01

297

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

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral or each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2014-10-01

298

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

Code of Federal Regulations, 2012 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral or each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2012-10-01

299

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

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral of each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2014-10-01

300

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

Code of Federal Regulations, 2011 CFR

...accessible. (b) Each propulsion, power, lighting, or distribution system...The neutral or each grounded generation and distribution system must...except the neutral of an emergency power generation system must be grounded...

2011-10-01

301

Toward Knowledge Propagation in an Omnidirectional Distributed Vision System  

E-print Network

Toward Knowledge Propagation in an Omnidirectional Distributed Vision System Emanuele Menegatti Enrico Pagello Takashi Minato Takayuki Nakamura Hiroshi Ishiguro Intelligent Autonomous Systems between the Omnidirectional Visual Agents of a Distributed Vision System. The application we chose

Menegatti, Emanuele

302

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

SciTech Connect

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

Clark, D.A.

1996-03-04

303

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

304

Distribution system planning using knowledge based expert system  

SciTech Connect

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

Ranjan, R.; Das, D. [Birla Inst. of Tech. and Science, Rajasthan (India). Electrical and Electronics Engineering Dept.; Kothari, D.P. [Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies

1995-12-31

305

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

306

The non-Markovian stochastic Schrodinger equation for open systems  

E-print Network

We present the non-Markovian generalization of the widely used stochastic Schrodinger equation. Our result allows to describe open quantum systems in terms of stochastic state vectors rather than density operators, without approximation. Moreover, it unifies two recent independent attempts towards a stochastic description of non-Markovian open systems, based on path integrals on the one hand and coherent states on the other. The latter approach utilizes the analytical properties of coherent states and enables a microscopic interpretation of the stochastic states. The alternative first approach is based on the general description of open systems using path integrals as originated by Feynman and Vernon.

Lajos Diosi; Walter T. Strunz

1997-06-22

307

The non-Markovian stochastic Schrödinger equation for open systems  

E-print Network

We present the non-Markovian generalization of the widely used stochastic Schrodinger equation. Our result allows to describe open quantum systems in terms of stochastic state vectors rather than density operators, without approximation. Moreover, it unifies two recent independent attempts towards a stochastic description of non-Markovian open systems, based on path integrals on the one hand and coherent states on the other. The latter approach utilizes the analytical properties of coherent states and enables a microscopic interpretation of the stochastic states. The alternative first approach is based on the general description of open systems using path integrals as originated by Feynman and Vernon.

Diósi, L; Diosi, Lajos; Strunz, Walter T.

1997-01-01

308

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

Microsoft Academic Search

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

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

2005-01-01

309

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

310

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

NASA Astrophysics Data System (ADS)

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

Rank, R.; Reynolds, R. G.

2005-12-01

311

A universal time-varying distributed H-system of degree 2.  

PubMed

A time-varying distributed H system is a splicing system which has the following feature: at different moments one uses different sets of splicing rules. The number of these sets is called the degree of the system. The passing from a set of rules to another one is specified in a cycle. It is a well known fact that any formal language can be generated by a time-varying distributed H-system of degree at least 7. Here we prove that there are universal time-varying distributed H-systems of degree 2. The question of whether or not there are universal time-varying distributed H-systems of degree 1 remains open. PMID:10636032

Margenstern, M; Rogozhin, Y

1999-10-01

312

Estimation of Velocity Distribution and Suspended Sediment Discharge in Open Channels Using Entropy  

E-print Network

????????????????.?????..... 6 2. LITERATURE REVIEW???????????????.????... 8 2.1 Entropy concept and theory???????????.?????. 8 2.1.1 Shannon entropy?????????????.????. 9 2.1.2 Tsallis entropy?????????????.????? 10 2.1.3 Principle of maximum entropy???????.????... 10...????????????..??? 20 2.3 Suspended sediment discharge in open channels??????..?? 20 3. EXPERIMENTAL AND FIELD DATA???????????..??.. 25 4. HYPOTHESIS ON THE CUMULATIVE DISTRIBUTION FUNCTION? 30 4.1 2D velocity distribution???????????..??????.. 30 4.1.1 Setting...

Cui, Huijuan

2011-08-08

313

Quantum hacking: attacking practical quantum key distribution systems  

NASA Astrophysics Data System (ADS)

Quantum key distribution (QKD) can, in principle, provide unconditional security based on the fundamental laws of physics. Unfortunately, a practical QKD system may contain overlooked imperfections and violate some of the assumptions in a security proof. Here, we report two types of eavesdropping attacks against a practical QKD system. The first one is "time-shift" attack, which is applicable to QKD systems with gated single photon detectors (SPDs). In this attack, the eavesdropper, Eve, exploits the time mismatch between the open windows of the two SPDs. She can acquire a significant amount of information on the final key by simply shifting the quantum signals forwards or backwards in time domain. Our experimental results in [9] with a commercial QKD system demonstrate that, under this attack, the original QKD system is breakable. This is the first experimental demonstration of a feasible attack against a commercial QKD system. This is a surprising result. The second one is "phase-remapping" attack [10]. Here, Eve exploits the fact that a practical phase modulator has a finite response time. In principle, Eve could change the encoded phase value by time-shifting the signal pulse relative to the reference pulse.

Qi, Bing; Fung, Chi-Hang Fred; Zhao, Yi; Ma, Xiongfeng; Tamaki, Kiyoshi; Chen, Christine; Lo, Hoi-Kwong

2007-09-01

314

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

315

Open Source Ch Control System Toolkit and Web-Based  

E-print Network

Open Source Ch Control System Toolkit and Web-Based Control System Design for Teaching Automatic, and WCCDM for teaching automatic control of linear time-invariant systems is presented. With the CCST.20454 Keywords: control systems; Web-based education INTRODUCTION Automatic control has become a major

Cheng, Harry H.

316

SODA: An Optimizing Scheduler for Large-Scale Stream-Based Distributed Computer Systems  

Microsoft Academic Search

This paper describes the SODA scheduler for System S, a highly scalable distributed stream processing system. Unlike traditional batch applications, streaming applications are\\u000a open-ended. The system cannot typically delay the processing of the data. The scheduler must be able to shift resource allocation\\u000a dynamically in response to changes to resource availability, job arrivals and departures, incoming data rates and so

Joel L. Wolf; Nikhil Bansal; Kirsten Hildrum; Sujay Parekh; Deepak Rajan; Rohit Wagle; Kun-lung Wu; Lisa Fleischer

2008-01-01

317

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

318

System approach to distributed sensor management  

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

319

ORAL PRESENTATION Open Access HTLV-1 world distribution and estimation of the  

E-print Network

ORAL PRESENTATION Open Access HTLV-1 world distribution and estimation of the number on Human Retroviruses: HTLV and Related Viruses Montreal, Canada. 26-30 June 2013 HTLV-1, identified 32 estimated the number of HTLV-1 carriers to be 10-20 millions. At that time, large regions had not been

Paris-Sud XI, Université de

320

Distribution System Analysis Tools for Studying High Penetration of PV  

E-print Network

Distribution System Analysis Tools for Studying High Penetration of PV with Grid Support Features Electric Energy System #12;#12;Distribution System Analysis Tools for Studying High Penetration of PV project titled "Distribution System Analysis Tools for Studying High Penetration of PV with Grid Support

321

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

322

Conserved current in Markovian open-quantum systems  

SciTech Connect

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

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

2006-06-15

323

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.

324

Distributed, cooperating knowledge-based systems  

NASA Technical Reports Server (NTRS)

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

Truszkowski, Walt

1991-01-01

325

Distributed Online Learning in Social Recommender Systems  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

326

Differential distributions of synechococcus subgroups across the california current system.  

PubMed

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

327

Nearest level spacing statistics in open chaotic systems: a generalization of the Wigner Surmise  

E-print Network

We investigate the nearest level spacing statistics of open chaotic wave systems. To this end we derive the spacing distributions for the three Wigner ensembles in the one-channel case. The theoretical results give a clear physical meaning of the modifications on the spacing distributions produced by the coupling to the environment. Based on the analytical expressions obtained, we then propose general expressions of the spacing distributions for any number of channels, valid from weak to strong coupling. The latter expressions contain one free parameter. The surmise is successfully compared with numerical simulations of non-Hermitian random matrices and with experimental data obtained with a lossy electromagnetic chaotic cavity.

Charles Poli; Germán A. Luna-Acosta; Hans-Jürgen Stockmann

2014-07-13

328

Hot Water Distribution System Model Enhancements  

SciTech Connect

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

Hoeschele, M.; Weitzel, E.

2012-11-01

329

A System for Open-Access 3 He Human Lung  

E-print Network

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

Walsworth, Ronald L.

330

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

331

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

332

RESEARCH ARTICLE Open Access Complex phylogenetic distribution of a non-  

E-print Network

into amino acids, is universal in nearly all genetic systems, including viruses, bacteria, archaebacteria reassignments have been traced to changes in tRNAs, either by single nucleotide substitution, base modification, and become reassigned ("captured") by muta- tions of noncognate tRNAs. This mechanism is essentially neutral

333

Distributed Pipeline Scheduling: A Framework for Distributed, Heterogeneous Real-Time System Design  

Microsoft Academic Search

This paper describes the Distributed Pipeline Scheduling Framework that provides a systematic approach to designing distributed, heterogeneous real- time systems. This paper formalizes Distributed Pipe- lining Scheduling by providing a set of abstractions and transformations to map real-time applications to sys- tem resources, to create highly efficient and predictable systems, and to de-compose the very complex multi- resource system timing

Saurav Chatterjee; Jay K. Strosnider

1995-01-01

334

CODA: a scalable, distributed data acquisition system  

SciTech Connect

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

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

1994-02-01

335

CODA: A scalable, distributed data acquisition system  

SciTech Connect

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

Watson, W.A. III; Chen, J.; Heyes, G.; Jastrzembski, E.; Quarrie, D. (CEBAF, Newport News, VA (United States))

1994-02-01

336

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

337

The AI Bus architecture for distributed knowledge-based systems  

NASA Technical Reports Server (NTRS)

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

Schultz, Roger D.; Stobie, Iain

1991-01-01

338

Distributed control system for turbine engines  

SciTech Connect

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

Shaffer, P.L. [General Electric Aircraft Engines, Cincinnati, OH (United States)

1999-01-01

339

43 CFR 418.27 - Distribution system operation.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Distribution system operation. 418.27 Section 418.27 ...NEWLANDS RECLAMATION PROJECT, NEVADA Operations and Management § 418.27 Distribution system operation. (a) The District must...

2010-10-01

340

Accountability in Cloud Computing and Distributed Computer Systems Hongda Xiao  

E-print Network

Abstract Accountability in Cloud Computing and Distributed Computer Systems Hongda Xiao 2014, authentication protocols, and encryption. With the rise of internet technologies, especially cloud computing mechanisms for realistic scenarios in cloud computing and distributed computer systems. First, we propose

Feigenbaum, Joan

341

49 CFR 191.11 - Distribution system: Annual report.  

Code of Federal Regulations, 2013 CFR

... false Distribution system: Annual report. 191.11 Section 191.11...NATURAL AND OTHER GAS BY PIPELINE; ANNUAL REPORTS, INCIDENT REPORTS, AND SAFETY-RELATED...191.11 Distribution system: Annual report. (a) General....

2013-10-01

342

49 CFR 191.11 - Distribution system: Annual report.  

Code of Federal Regulations, 2011 CFR

... false Distribution system: Annual report. 191.11 Section 191.11...NATURAL AND OTHER GAS BY PIPELINE; ANNUAL REPORTS, INCIDENT REPORTS, AND SAFETY-RELATED...191.11 Distribution system: Annual report. (a) General....

2011-10-01

343

49 CFR 191.11 - Distribution system: Annual report.  

Code of Federal Regulations, 2010 CFR

... false Distribution system: Annual report. 191.11 Section 191.11...NATURAL AND OTHER GAS BY PIPELINE; ANNUAL REPORTS, INCIDENT REPORTS, AND SAFETY-RELATED...191.11 Distribution system: Annual report. (a) Except as...

2010-10-01

344

49 CFR 191.11 - Distribution system: Annual report.  

Code of Federal Regulations, 2012 CFR

... false Distribution system: Annual report. 191.11 Section 191.11...NATURAL AND OTHER GAS BY PIPELINE; ANNUAL REPORTS, INCIDENT REPORTS, AND SAFETY-RELATED...191.11 Distribution system: Annual report. (a) General....

2012-10-01

345

Open Source Software in Critical Systems  

Microsoft Academic Search

This paper summarizes the main conclusions and recommendations from a Working Group on “Open Source Software and Dependability”.\\u000a The Group was launched in the framework of a cooperative structure, a Network for Dependability Engineering, and gathered\\u000a representatives often academic and industrial organizations.

Philippe David; Hélène Waeselynck; Yves Crouzet

346

Virtual Fingerprinting as a Foundation for Reputation in Open Systems  

E-print Network

-to-peer systems. Open systems that attempt to make access control decisions based on the identities of their par entity in attribute-based trust management systems. We then show how these identities can be turned {adamlee,winslett}@cs.uiuc.edu Abstract. The lack of available identity information in attribute

347

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 controls. 1 Introduction The possibility of actively controlling the state of quantum mechanical systems], [12], [13], [17]). If the requirement for a control law is to steer the state of the system from

Sontag, Eduardo

348

RESEARCH Open Access Local and systemic innate immune response  

E-print Network

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

Paris-Sud XI, Université de

349

Developing open systems using theories and models of the world  

SciTech Connect

This paper considers an open system as such that can deal with inputs that were not anticipated by the designer. Using an ATR system as an example, we show how the combination of logic with software engineering techniques allowed us to improve the performance of the system.

Kokar, M.M.; Korona, Z. [Northeastern Univ., Boston, MA (United States)

1996-12-31

350

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

NASA Astrophysics Data System (ADS)

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

Thompson, Benjamin A.; Frinchaboy, Peter M.

2015-01-01

351

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

352

Physicomimetics Positioning Methodology for Distributed Autonomous Systems  

E-print Network

, by acting as a distributed computational mesh. Keywords: physicomimetics; artificial physics; chemical plume, to collect, aggregate, and fuse distributed data into a tactical assessment. The result is enhanced

353

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

PubMed Central

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

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

2014-01-01

354

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

PubMed

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

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

2014-01-01

355

Sun's Network File System (NFS) One of the first uses of distributed client/server computing was in the  

E-print Network

for easy sharing of data across clients. Thus, if you access a file on one machine (Client 0 application issues system calls to the client-side file system (such as open(), read(), write(), close48 Sun's Network File System (NFS) One of the first uses of distributed client/server computing

Arpaci-Dusseau, Remzi

356

Wide area network performance modeling of distributed energy management systems  

Microsoft Academic Search

A distributed energy management system consists of networked hardware and software capable of monitoring and controlling the operations of an electric utility. When several of these distributed systems are connected to each other via wide area network connections, then a truly geographically distributed environment exists where data between systems can be shared. Heavy communication network loads and transit time constraints

C. Langhorne; C. Carlson; S. Chowdhury

1993-01-01

357

Wide area network performance modeling of distributed energy management systems  

Microsoft Academic Search

A distributed energy management system consists of networked hardware and software capable of monitoring and controlling the operations of an electric utility. When several of these distributed systems are connected to each other via wide area network connections, then a truly geographically distributed environment exists where data between systems can be shared. Heavy communication network loads and transit time constraints

C. Langhorne; C. Carlson; S. Chowdhury

1994-01-01

358

Amoeba: A Distributed Operating System for the 1990s  

Microsoft Academic Search

Amoeba is the distributed system developed at the Free University (VU) and Centre for Mathematics and Computer Science (CWI), both in Amsterdam. Throughout the project's ten-year history, a major concern of the designers has been to combine the research themes of distributed systems, such as high availability, use of parallelism and scalability, with simplicity and high performance. Distributed systems are

Sape J. Mullender; Guido Van Rossum; Andrew S. Tanenbaum; Robbert Van Renesse; Hans Van Staveren

1990-01-01

359

Waiting time distribution for continuous stochastic systems  

NASA Astrophysics Data System (ADS)

The waiting time distribution (WTD) is a common tool for analyzing discrete stochastic processes in classical and quantum systems. However, there are many physical examples where the dynamics is continuous and only approximately discrete, or where it is favourable to discuss the dynamics on a discretized and a continuous level in parallel. An example is the hindered motion of particles through potential landscapes with barriers. In the present paper we propose a consistent generalization of the WTD from the discrete case to situations where the particles perform continuous barrier crossing characterized by a finite duration. To this end, we introduce a recipe to calculate the WTD from the Fokker-Planck (Smoluchowski) equation. In contrast to the closely related first passage time distribution (FPTD), which is frequently used to describe continuous processes, the WTD contains information about the direction of motion. As an application, we consider the paradigmatic example of an overdamped particle diffusing through a washboard potential. To verify the approach and to elucidate its numerical implications, we compare the WTD defined via the Smoluchowski equation with data from direct simulation of the underlying Langevin equation and find full consistency provided that the jumps in the Langevin approach are defined properly. Moreover, for sufficiently large energy barriers, the WTD defined via the Smoluchowski equation becomes consistent with that resulting from the analytical solution of a (two-state) master equation model for the short-time dynamics developed previously by us [Phys. Rev. E 86, 061135 (2012), 10.1103/PhysRevE.86.061135]. Thus, our approach "interpolates" between these two types of stochastic motion. We illustrate our approach for both symmetric systems and systems under constant force.

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

2014-12-01

360

A radial distribution function-based open boundary force model for multi-centered molecules  

NASA Astrophysics Data System (ADS)

We derive an expression for radial distribution function (RDF)-based open boundary forcing for molecules with multiple interaction sites. Due to the high-dimensionality of the molecule configuration space and missing rotational invariance, a computationally cheap, 1D approximation of the arising integral expressions as in the single-centered case is not possible anymore. We propose a simple, yet accurate model invoking standard molecule- and site-based RDFs to approximate the respective integral equation. The new open boundary force model is validated for ethane in different scenarios and shows very good agreement with data from periodic simulations.

Neumann, Philipp; Eckhardt, Wolfgang; Bungartz, Hans-Joachim

2014-12-01

361

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

362

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

DOEpatents

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

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

2014-11-11

363

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

364

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

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

365

Clock distribution system for digital computers  

DOEpatents

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

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

1981-01-01

366

Guidelines for the implementation of an open source information system  

SciTech Connect

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

Doak, J.; Howell, J.A.

1995-08-01

367

Distributed information system on molecular spectroscopy  

NASA Astrophysics Data System (ADS)

The urgency of creating the information-computational systems (ICS) on molecular spectroscopy follows from the circumstance that for some molecules the number of calculated energy levels counts hundreds of thousands, and the number of spectral lines sometimes reaches hundreds of millions. Publication of such data volumes in regular journals is inappropriate. Comparison of different calculated spectral characteristics or their comparison with experimental data beyond computer processing is hopeless. We find information systems to be an adequate form for holding such data volumes and a toolkit for handling them. Correct digital data processing requires appropriate sets of metadata arranged in the form of ontology of molecular spectroscopy. Our information system provides the data on spectral line parameters, water molecule energy levels, and absorption coefficients. Within this distributed IS one can solve two types of problems: manipulation with data and calculation of spectral functions. Among the latest experimental data in the IS there are data obtained at the Institute of Applied Physics RAS. To calculate the absorption coefficients for the molecules of carbonic acid gas, we take into consideration spectral line interference.

Bykov, A. D.; Fazliev, A. Z.; Kozodoev, A. V.; Privezentsev, A. I.; Sinitsa, L. N.; Tonkov, M. V.; Filippov, N. N.; Tretyakov, M. Yu.

2006-12-01

368

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

PubMed Central

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

2011-01-01

369

Fault-tolerant power distribution system  

NASA Technical Reports Server (NTRS)

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

Volp, Jeffrey A. (Inventor)

1987-01-01

370

Driven harmonic oscillator as a quantum simulator for open systems  

E-print Network

We show theoretically how a driven harmonic oscillator can be used as a quantum simulator for non-Markovian damped harmonic oscillator. In the general framework, the results demonstrate the possibility to use a closed system as a simulator for open quantum systems. The quantum simulator is based on sets of controlled drives of the closed harmonic oscillator with appropriately tailored electric field pulses. The non-Markovian dynamics of the damped harmonic oscillator is obtained by using the information about the spectral density of the open system when averaging over the drives of the closed oscillator. We consider single trapped ions as a specific physical implementation of the simulator, and we show how the simulator approach reveals new physical insight into the open system dynamics, e.g. the characteristic quantum mechanical non-Markovian oscillatory behavior of the energy of the damped oscillator, usually obtained by the non-Lindblad-type master equation, can have a simple semiclassical interpretation.

Jyrki Piilo; Sabrina Maniscalco

2006-10-03

371

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

372

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

373

Models and Feedback Stabilization of Open Quantum Systems  

E-print Network

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

Pierre Rouchon

2014-07-26

374

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

375

Control Landscapes for Observable Preparation with Open Quantum Systems  

E-print Network

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

Rebing Wu; Alexander Pechen; Herschel Rabitz; Michael Hsieh; Benjamin Tsou

2007-08-16

376

Open System Dynamics with Non-Markovian Quantum Trajectories  

Microsoft Academic Search

A non-Markovian stochastic Schrödinger equation for a quantum system coupled to an environment of harmonic oscillators is presented. The ensemble average recovers the reduced density matrix without approximation and hence it allows one to determine open system dynamics with strong and non-Markovian environmental effects in a very efficient way. We demonstrate the power of our approach with several illustrative examples.

Walter T. Strunz; Lajos Diósi; Nicolas Gisin

1999-01-01

377

Stochastic pure state representation for open quantum systems  

Microsoft Academic Search

We show that the usual master equation formalism of markovian open quantum systems is completely equivalent to a certain state vector formalism. The state vector of the system satisfies a given frictional Schrödinger equation except for random instant transitions of discrete nature. Hasse's frictional hamiltonian is recovered for the damped harmonic oscillator.

L. Diósi

1986-01-01

378

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

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

379

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

380

DOMES: A distributed ocean modelling system  

SciTech Connect

With research interests shifting away from primarily military or industrial applications to more environmental applications, the area of ocean modelling has become an increasingly popular and exciting area of research. This paper presents a CIPS (Computation Field Simulation) system customized for the solution of oceanographic problems. This system deals primarily with the generation of simple, yet efficient grids for coastal areas. The two primary grid approaches are both structured in methodology. The first approach is a standard approach which is used in such popular grid generation softwares as GE-NIE++, EAGLEVIEW, and TIGER, where the user defines boundaries via points, lines, or curves, varies the distribution of points along these boundaries and then creates the interior grid. The second approach is to allow the user to interactively select points on the screen to form the boundary curves and then create the interior grid from these spline curves. The program has been designed with the needs of the ocean modeller in mind so that the modeller can obtain results in a timely yet elegant manner. The modeller performs four basic steps in using the program. First, he selects a region of interest from a popular database. Then, he creates a grid for that region. Next, he sets up boundary and input conditions and runs a circulation model. Finally, the modeller visualizes the output.

Shaunak, S.K.; Soni, B.K. [Mississippi State Univ., MS (United States)

1996-12-31

381

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

382

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

383

Novel architectures and control for distributed UPS systems  

Microsoft Academic Search

This paper is concerned with the circuit configuration and control of parallel distributed uninterruptible power supply (UPS) systems. These systems are expected to provide high quality continuous power to critical loads in the face of mains disturbances or failure. This paper discusses the system configuration issues of distributed UPS. These can be classified as online or line-interactive systems. Decentralized control

M. C. Chandorkar; D. M. Divan; Y. Hu; B. Banerjee

1994-01-01

384

Study of distributed computing system based on web services  

NASA Astrophysics Data System (ADS)

For the security issues in distributed computing applications, combined with Web Services management system design and implementation, based on the research of Web Services and its security technology, this paper designs a distributed computing test system based on Web Services, in detail describes its key technologies, which further validates the advantages of Web Services technology for the distributed computing in loosely coupled network environment.

Wang, Lu-Feng

2013-03-01

385

A Study of Application Development under Proprietary and Open Source Systems  

NASA Astrophysics Data System (ADS)

Our experience has shown that utilization of either proprietary or open source software systems for application development can be a very enabling experience. The systems in consideration are IDL*, a stable, commercial software package initially developed for astronomical applications and Python**, a younger, evolving, Open Source system whose use in astronomy is growing rapidly. We will attempt to show from our perspectives some of the advantages and disadvantages of using these systems for application development. Both systems are interpreted programming languages which provide the user with powerful, and easy to use, interactive environments. They facilitate rapid prototyping, have accessible graphics and GUI capabilities, support an array of numerical functions, and can interface to compiled languages. The fundamental differences between the languages are manifested in the breadth and/or maturity of the available capabilities, and the accessibility to the underlying language structure. Whether to choose a commercial or open source product is entirely dependent upon the risk model of an individual or institution. A mature system can provide a sense of stability and security in time-tested functionality; an evolving system can provide cutting-edge technologies on a rapid timescale. Our experiences have taught us that it is most important to be aware of the systems available, as well as their strengths and weaknesses, so that we can choose the appropriate technology for the problem at hand. * IDL Interactive Data Language, is distributed by Research Systems, Inc. (RSI), a Kodak Company. ** Python was created by Guido van Rossum, 2001 Python Software Foundation.

Stobie, E. B.; de La Peña, M. D.

386

A Hierarachical Adaptive Distributed System-Level Diagnosis Algorithm  

Microsoft Academic Search

Consider a system composed of N nodes that can be faulty or fault-free. The purpose of distributed system-level diagnosis is to have each fault-free node determine the state of all nodes of the system. This paper presents a Hierarchical Adaptive Distributed System-level Diagnosis (Hi-ADSD) algorithm, which is a fully distributed algorithm that allows every fault-free node to achieve diagnosis in,

Elias Procópio Duarte Jr.; Takashi Nanya

1998-01-01

387

DEVELOPMENT OF A SORBENT DISTRIBUTION AND RECOVERY SYSTEM  

EPA Science Inventory

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

388

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

389

Distributed information system (water fact sheet)  

USGS Publications Warehouse

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

Harbaugh, A.W.

1986-01-01

390

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

391

MFR: Multi-Loss Flexible Recovery in Distributed Storage Systems  

Microsoft Academic Search

Distributed storage systems provide reliable access to data through redundancy spread in network system. A key goal is to minimize bandwidth overhead to maintain the redundancy. This paper studies the flexible recovery from multiple node failures in distributed storage systems. Via a cut-based analysis of information flow graph, we obtain a lower bound of maintenance bandwidth for multi-loss flexible recovery

Xiaozhao Wang; Yinlong Xu; Yuchong Hu; Kaiqian Ou

2010-01-01

392

Proportional-Share Scheduling for Distributed Storage Systems  

Microsoft Academic Search

Fully distributed storage systems have gained popularity in the past few years because of their ability to use cheap commodity hardware and their high scalability. While there are a num- ber of algorithms for providing differentiated quality of service to clients of a centralized storage system, the problem has not been solved for distributed storage systems. Providing perfor- mance guarantees

Yin Wang; Arif Merchant

2007-01-01

393

ConcurrentMentor: A Visualization System for Distributed Programming Education  

E-print Network

ConcurrentMentor: A Visualization System for Distributed Programming Education Steve Carr is challenging for students. In order to assist in distributed systems instruction, we have developed Concurrent to the visualization system is generated by an accompanying communica- tion library that closely follows abstractions

Shene, Ching-Kuang

394

Performance estimation for real-time distributed embedded systems  

Microsoft Academic Search

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

Ti-yen Yen; Wayne Wolf

1995-01-01

395

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

396

Herding Sheep: Live System Development for Distributed Augmented Reality  

E-print Network

Herding Sheep: Live System Development for Distributed Augmented Reality Asa MacWilliams, Christian been widely different and taylored to specific tasks. In this paper, we use the example of the SHEEP, debugging and altering a com- plex, distributed, highly interactive AR system. The SHEEP system was designed

Bruegge, Bernd

397

Optimal Dispatch of Photovoltaic Inverters in Residential Distribution Systems  

E-print Network

Optimal Dispatch of Photovoltaic Inverters in Residential Distribution Systems Emiliano Dall. The increased penetration of roof-top photovoltaic (PV) systems has highlighted pressing needs to address power--Distribution networks, inverter control, optimal power flow (OPF), photovoltaic (PV) systems, sparsity, voltage

Giannakis, Georgios

398

Job Admission and Resource Allocation in Distributed Streaming Systems  

Microsoft Academic Search

This paper describes a new and novel scheme for job admis- sion and resource allocation employed by the SODA scheduler in System S. Capable of processing enormous quantities of streaming data, Sys- tem S is a large-scale, distributed stream processing system designed to handle complex applications. The problem of scheduling in distributed, stream-based systems is quite unlike that in more

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

2009-01-01

399

Tableaux Methods for Access Control in Distributed Systems  

Microsoft Academic Search

The aim of access control is to limit what users of distributed systems can do directly or through their programs. As the size of the systems and the sensitivity of data increase formal methods of analysis are often required. This paper presents a prefixed tableaux method for the calculus of access control in distributed system developed at DEC-SRC by Abadi,

Fabio Massacci

1997-01-01

400

Distributed Antenna System: Performance Analysis in Multi-user Scenario  

E-print Network

Distributed Antenna System: Performance Analysis in Multi-user Scenario Lin Dai Dept. Electronic--This paper provides a comparative study of the distributed antenna system (DAS) and the conventional co- located antenna system (CAS) in the multi-user scenario. It is demonstrated that thanks to the decrease

Dai, Lin

401

Self-Managed Leasing for Distributed Systems Kevin Bowers  

E-print Network

Self-Managed Leasing for Distributed Systems Kevin Bowers Renssalaer Polytechnic Institute bowerk enabled system, given a fixed allocation of resources, to vary lease periods to achieve the best responsiveness. Keywords algorithm, self-managing, performance, Jini, leasing 1. INTRODUCTION Distributed systems

Mills, Kevin

402

Strategic evaluation of energy and distribution management systems  

Microsoft Academic Search

To maintain a secure and economic operation for huge power systems, some advanced power system control facilities and technologies, such as energy management system (EMS) and distribution management system (DMS), have been introduced into business operations since 1995. In average, an EMS\\/DMS system can run no more than ten years in China. Accordingly, most of the existing systems in China

Hsing Hung Chen; Chao Ma

2008-01-01

403

Elimination of direct current distribution systems from new generating stations  

SciTech Connect

This paper advances the concept that it may be both possible and advantageous to eliminate the traditional direct current distribution system from a new generating station. The latest developments in uninterruptible power supply (UPS) technology are what have made this option technically feasible. A traditional dc distribution system will be compared to an ac distribution system supplied by a UPS to investigate the merits of the proposed approach.

Jancauskas, J.R. [Parsons Power Group, Chattanooga, TN (United States)

1996-12-31

404

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

405

Automation of the Athens (Tennessee) electric power distribution system  

SciTech Connect

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

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

1988-01-01

406

Control of multi-evaporator air-conditioning systems for flow distribution  

Microsoft Academic Search

Modern air-conditioners incorporate variable-speed compressors and variable-opening expansion valves as the actuators for improving cooling performance and energy efficiency. These actuators have to be properly feedback-controlled; otherwise the systems may exhibit even poorer performance than the conventional machines which use fixed-speed compressors and mechanical expansion valves. In this paper, a control strategy with flow distribution capability is proposed for multi-evaporator

Jin-Long Lin; T.-J. Yeh

2009-01-01

407

RFID based production and distribution management systems for home appliance industry  

Microsoft Academic Search

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

Xubing Chen; Yuhui Wang; Zhouping Yin

2010-01-01

408

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

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

409

Sensor Networks for Monitoring and Control of Water Distribution Systems  

E-print Network

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

Whittle, Andrew

410

Distribution of Systemic Clarithromycin to Gingiva  

PubMed Central

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

Burrell, Renita C.; Walters, John D.

2008-01-01

411

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

412

Empirical Semantics of Agent Communication in Open Systems  

Microsoft Academic Search

The paper proposes a novel approach to the semantics of communication of self-interested and autonomous agents in open systems. It deflnes the semantics of communicative acts primarily as the observable efiect of their actual use in social encounters, and difiers thus fundamentally from men- talistic and current objectivist approaches to the semantics of agent communication languages. Empirical communica- tion semantics

Matthias Nickles; Gerhard Weiss

2003-01-01

413

Non-Markovian Open Quantum Systems: Lorentzian from Ohmic  

E-print Network

As a general mission, reduced dynamics and master equations are advocated as alternative method and philosophy instead of Green functions, Kubo theory and the like. A smart reduction of the Lorentzian open system to the Ohmic one (Imamoglu, 1994) is presented in simple terms.

Diósi, Lajos

2011-01-01

414

A Flexible, Open, Decentralized System for Digital Pathology Networks  

E-print Network

A Flexible, Open, Decentralized System for Digital Pathology Networks Robert SCHULERa,1 and David E and sharing of digitized microscopy slides and new methods for digital pathology. Collaborative research centers, outsourced medical services, and multi-site organizations stand to benefit from sharing pathology

Chervenak, Ann

415

An Open-Source Learning Content Management and Assessment System  

E-print Network

Assembly Course Management LON-CAPA Architecture Shared Cross-Institutional Resource Library (Base de Dados-Institutional Resource Library Resource Assembly Course Management Resource Assembly Course Management #12;CourseLON-CAPA An Open-Source Learning Content Management and Assessment System Gerd Kortemeyer

416

Carbon 14 dating of groundwater from closed and open systems  

Microsoft Academic Search

Groundwaters may be dated by using carbon 14, provided that the raw data are properly adjusted. However, adjustment factors determined from geochemical or isotopic measurements and based on simple models of carbonate dissolution do not always agree with adjustment factors obtained by independent means. In this paper, established adjustment methods are reinterpreted in terms of closed and open system models

T. M. L. Wigley

1975-01-01

417

Feedback interconnection of open quantum systems: A small gain theorem  

Microsoft Academic Search

This paper examines the stability of quan- tum feedback networks. We introduce a novel charac- terization, in terms of equivalence classes of operators, that may be used to describe open quantum systems. In this characterization, equivalence classes of operators are shown to be elements of a Banach space such that the norm of an operator is analogous to the root

Ram Abhinav Somaraju; Ian R. Petersen

2009-01-01

418

Frozen Natural Orbital for open-shell systems within  

E-print Network

Frozen Natural Orbital (FNO) for open-shell systems within Equation of motion-coupled cluster (EOM of motion-coupled cluster (EOM-CC) approach Arik Landau Anna I. Krylov #12;Outline: · motivation is essential Wave-function based methods, e.g., EOM-CC, provide accurate and reliable calculations #12

Krylov, Anna I.

419

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

E-print Network

Open Giant Intelligent Information Systems and Its Multiagent-Oriented System Design Longbing Cao field of complex intelligent information systems. In this paper, we mainly discuss about system design intelligent information system, many computing paradigms, such as object-oriented analysis and design

Cao, Longbing

420

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

421

Government Open Systems Interconnection Profile (GOSIP) transition strategy  

NASA Astrophysics Data System (ADS)

This thesis analyzes the Government Open Systems Interconnection Profile (GOSIP) and the requirements of the Federal Information Processing Standard (FIPS) Publication 146-1. It begins by examining the International Organization for Standardization (ISO) Open Systems Interconnection (OSI) architecture and protocol suites and the distinctions between GOSIP version one and two. Additionally, it explores some of the GOSIP protocol details and discusses the process by which standards organizations have developed their recommendations. Implementation considerations from both government and vendor perspectives illustrate the barriers and requirements faced by information systems managers, as well as basic transition strategies. The result of this thesis is to show a transition strategy through an extended and coordinated period of coexistence due to extensive legacy systems and GOSIP product unavailability. Recommendations for GOSIP protocol standards to include capabilities outside the OSI model are also presented.

Laxen, Mark R.

1993-09-01

422

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

E-print Network

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

Paris-Sud XI, Université de

423

A novel multi-objective PSO for electrical distribution system planning incorporating distributed generation  

Microsoft Academic Search

This paper presents a novel particle swarm optimization (PSO) based multi-objective planning approach for electrical distribution\\u000a systems incorporating distributed generation (DG). The proposed strategy can be used for planning of both radial and meshed\\u000a networks incorporating DG. The DG plays an important role in the distribution system planning due to its increasing use motivated\\u000a by reduction of power loss, voltage

S. Ganguly; N. C. Sahoo; D. Das

2010-01-01

424

Architectures for Distributed Information Systems Supporting Environmental Simulation  

Microsoft Academic Search

Different distributed environmental simulation systems are presented. They take advantage of the possibilities of modern network technologies to gather input data, perform simulation and spread the simulation results. The term `distributed' applies in this context both to the simulation, which is a parallel (distributed) simulation on computer networks, and to the fact, that all components (pre- and postprocessing and the

Steffen Unger; Torsten Asselmeyer

2000-01-01

425

Control and supervisory system for power distribution equipment  

Microsoft Academic Search

A control and supervisory system for power distribution equipment is described including a plurality of terminal control devices each controlling a corresponding power distribution device connected therewith, each of the terminal control devices comprising: control instruction means in each terminal device operable to generate and output a control command for controlling the plurality of power distribution devices, the control command

Ichiro Arinobu; Hirohisa Mizuhara; Yasuhiro Ishii; Katsuya Sakai; Hiromitsu. Takahashi

1993-01-01

426

High-level language support for programming distributed systems  

Microsoft Academic Search

A strategy for simplifying the programming of heterogeneous distributed systems is presented. The approach used is based on integrating a high-level distributed programming model, the process model, directly into programming languages. Distributed applications written in such languages are portable across different environments, are shorter, and are simpler to develop than similar applications developed using conventional approaches. The process model is

Joshua S. Auerbach; David F. Bacon; Arthur P. Goldberg; Germán S. Goldszmidt; Ajei S. Gopal; Mark T. Kennedy; Andy Lowry; James R. Russell; William Silverman; Robert E. Strom; Daniel M. Yellin; Shaula Yemini

1992-01-01

427

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

428

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

NASA Astrophysics Data System (ADS)

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

Mitra, Parag

429

A Configuration and Control Method of DC Loop Type Distribution System Including Distributed Generators  

NASA Astrophysics Data System (ADS)

In the large-scale factories like ironworks, many power electronic inverter loads exist, and these inverter loads are connected into ac systems by using rectifiers. On the other hand, DGs (Distributed Generators) such as photovoltaic generators and fuel cells, or ESSs (Energy Storage Systems) such as secondary batteries and SMESs (Superconducting Magnetic Energy Strages), which are dc power sources will be introduced to distribution systems more and more. These are connected into ac systems by using inverters. Therefore, it is expected that some countermeasures to achieve a dc distribution system which can reduce power losses due to rectifiers and inverters, should be developed. In this paper, a dc loop type distribution system is proposed as one of the new dc distribution system configurations. The calculation results of power losses for the dc loop type distribution system are compared with those for an ac distribution system. Moreover, this paper shows configurations and simulation results of the inverter, bi-directional rectifier and PFC (Power Factor Corrector) used in this system.

Saisho, Masaki; Ise, Toshifumi; Tsuji, Kiichiro

430

PAR and Supply Distribution System The PAR Program is administered by Materials Logistics (Central Distribution)  

E-print Network

Logistics (Central Distribution) Services, a division of Materials Management. · The PAR Program is focused, except in the OR and NICU. (Materials Management will be reviewing a PAR system for the multiple units#12;PAR and Supply Distribution System OVERVIEW · The PAR Program is administered by Materials

Oliver, Douglas L.

431

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...

432

Lindblad master equation approach to superconductivity in open quantum systems  

NASA Astrophysics Data System (ADS)

We consider an open quantum Fermi system which consists of a single degenerate level with pairing interactions embedded into a superconducting bath. The time evolution of the reduced density matrix for the system is given by the Linblad master equation, where the dissipators describe exchange of Bogoliubov quasiparticles with the bath. We obtain fixed points of the time evolution equation for the covariance matrix and study their stability by analyzing full dynamics of the complex order parameter.

Kosov, Daniel S.; Prosen, Tomaž; Žunkovi?, Bojan

2011-11-01

433

Quantum decay of an open chaotic system: a semiclassical approach  

E-print Network

We study the quantum probability to survive in an open chaotic system in the framework of the van Vleck-Gutzwiller propagator and present the first such calculation that accounts for quantum interference effects. Specifically we calculate quantum deviations from the classical decay after the break time for both broken and preserved time-reversal symmetry. The source of these corrections is identified in interfering pairs of correlated classical trajectories. In our approach the quantized chaotic system is modelled by a quatum graph.

Mathias Puhlmann; Holger Schanz; Tsampikos Kottos; Theo Geisel

2005-03-13

434

Distillation of Bell states in open systems  

SciTech Connect

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

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

2010-04-15

435

Open Architecture Submarine Cable Observatory Systems  

Microsoft Academic Search

To deliver high power and broadband communication to the ocean floor requires a number of changes to existing technology developed to bridge oceans from shore to shore. The dry-dry solution is well mastered and although it evolves over time following technological innovations, adapting it to become a dry-wet solution represents a major technical challenge. The cabled observatory system developed for

A. Lecroart; N. Hazell; G. Waterworth; J.-F. Marcerou

2007-01-01

436

A support architecture for reliable distributed computing systems  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

437

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

438

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.

Gordon, K J; Collins, R J; Rech, I; Cova, S D; Townsend, P D; Buller, G S; Gordon, Karen J.; Fernandez, Veronica; Collins, Robert J.; Rech, Ivan; Cova, Sergio D.; Townsend, Paul D.; Buller, Gerald S.

2006-01-01

439

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

440

Motion Planning for Metamorphic Systems: Feasibility, Decidability and Distributed  

E-print Network

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

Dumitrescu, Adrian

441

Space Station Freedom power management and distribution system design  

NASA Technical Reports Server (NTRS)

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

Teren, Fred

1989-01-01

442

Open Source Public Sector Business Intelligence Systems  

Microsoft Academic Search

\\u000a Although business intelligence (BI) solutions have been a long-standing topic of major interest in private sector, public\\u000a administrations (PA), however, took only first steps towards strategic management. While PA are obliged to implement new public\\u000a management (NPM) approaches, such as new accounting systems or an output-oriented management, to collect management-relevant\\u000a data, there is little support regarding how to employ these

Jörg Becker; Björn Niehaves; Felix Müller-Wienbergen; Martin Matzner

443

Experimental specification of open systems evolution physical principles  

NASA Astrophysics Data System (ADS)

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

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

444

Use of natural gas distribution systems to deliver hydrogen  

SciTech Connect

A complex system of gas distribution equipment, consisting of many kinds of pipes, fittings, meters, regulators, valves, and other equipment typical of present-day gas distribution systems, was constructed in the laboratory at the Institute of Gas Technology. The equipment was hooked up in a loop system. The system was operated on natural gas for a few weeks before being switched to pure hydrogen for a 6-month test. The results of the test are summarized.

Gregory, D.P.

1980-01-01

445

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

446

Structuring Distributed Systems for Recoverability and Crash Resistance  

Microsoft Academic Search

An object-oriented multilevel model of computation is used to discuss recoverability and crash resistance issues in distributed systems. Of particular importance are the issues that are raised when recoverability and crash resistance properties are desired from objects whose concrete representations are distributed over several nodes. The execution of a program at a node of the system can give rise to

SANTOSHKUMAR SHRIVASTAVA

1981-01-01

447

TESLA Report 2001-37 THE TESLA CRYOGENIC DISTRIBUTION SYSTEM  

E-print Network

with a quadrupole and dipole steering coils. The paper describes the cryogenic distribution system necessaryTESLA Report 2001-37 THE TESLA CRYOGENIC DISTRIBUTION SYSTEM S. Wolff, H. Lierl, B. Petersen, DESY Electron Laser (FEL) with wave lengths down to 0.1 nm. The accelerating structures consist of 1.3 GHz

448

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

449

Using Replication and Partitioning to Build Secure Distributed Systems  

E-print Network

policies; this problem is even more acute in distributed systems with mutual dis­ trust. This paper securely on a distributed system with untrusted hosts. The code and data of the computation are partitioned, and without placing undue trust in any host. The compiler automatically generates secure run­time protocols

Zdancewic, Steve

450

Using Replication and Partitioning to Build Secure Distributed Systems  

E-print Network

policies; this problem is even more acute in distributed systems with mutual dis- trust. This paper securely on a distributed system with untrusted hosts. The code and data of the computation are partitioned, and without placing undue trust in any host. The compiler automatically generates secure run-time protocols

Zdancewic, Steve

451

Stability and Stabilization of Distributed time Delay Systems Frederic Gouaisbaut  

E-print Network

Stability and Stabilization of Distributed time Delay Systems Fr´ed´eric Gouaisbaut Abstract-- This paper is dedicated to the stability and stabi- lization of state-distributed delay systems. The key idea this reformulation, new stability criterion is proposed and is formulated in the form of Linear Matrix Inequality

Boyer, Edmond

452

A Cognitive Fault Diagnosis System for Distributed Sensor Networks  

E-print Network

1 A Cognitive Fault Diagnosis System for Distributed Sensor Networks Cesare Alippi, IEEE Fellow positives induced by the model bias of the HMMs. Index Terms--Fault diagnosis; distributed sensor network and inappropriate control actions. A Fault Diagnosis System plays the important role of su- pervising the process

Alippi, Cesare

453

Simulation-based test adequacy criteria for distributed systems  

Microsoft Academic Search

Developers of distributed systems routinely construct discrete-event simulations to help understand and evaluate the behavior of inter-component protocols. Simulations are abstract models of systems and their environments, captur- ing basic algorithmic functionality at the same time as they focus attention on properties critical to distribution, includ- ing topology, timing, bandwidth, and overall scalability. We claim that simulations can be treated

Matthew J. Rutherford; Antonio Carzaniga; Alexander L. Wolf

2006-01-01

454

Locally distributed automation – but with which fieldbus system?  

Microsoft Academic Search

Discusses the distribution of application functions to process-oriented field devices and process-remote components in distributed automation systems. Describes the use of fieldbus systems, function block technology based on standardised function blocks and a suitable infrastructure to enable these function blocks to cooperate during run time.

Peter Neumann

1999-01-01

455

Distributed collaborative decision support system for rocket launch operation  

Microsoft Academic Search

This paper presents an overview of a decision support system for rocket launch operation from the viewpoint of distributed collaboration mechanisms. The system comprises interface agents that mediate between operators on site or support engineers in distance and various Web services that function as large-grain-size task modules for operation support. In order to orchestrate the distributed Web services over the

Shohei Misono; Seiji Koide; Norikazu Shimada; Masanori Kawamura; Susumu Nagano

2005-01-01

456

Short Paper: Troubleshooting Distributed Systems via Data Mining  

Microsoft Academic Search

Through massive parallelism, distributed systems enable the multiplication of productivity. Unfortunately, increas- ing the scale of available machines to users will also mul- tiply debugging when failure occurs. Data mining allows the extraction of patterns within large amounts of data and therefore forms the foundation for a useful method of de- bugging, particularly within such distributed systems. This paper outlines

David A. Cieslak; Douglas Thain; Nitesh V. Chawla

457

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

458

Microeconomic Algorithms for Load Balancing in Distributed Computer Systems  

Microsoft Academic Search

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

Donald F. Ferguson; Yechiam Yemini; Cliristos Nikolaou

1988-01-01

459

Design tool for under-floor air distribution system  

Microsoft Academic Search

Under-floor air distribution (UFAD) system can provide indoor air quality improvement and energy saving potential. The conditioned air is supplied directly from the floor diffusers to the occupied zone and exhausted through the return grille on the ceiling. Partial thermal stratification within the occupied zone can be generated. Higher air distribution effectiveness can be achieved when the system is properly

Guangqing Xue

2011-01-01

460

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...

461

Quantum speedup for multi-qubit open systems  

E-print Network

Quantum speed limit (QSL) time captures the intrinsic minimal time interval for a quantum system evolving from an initial state to a target state. In single qubit open systems, it was found that the memory (non-Markovian) effect of environment plays an essential role in accelerating quantum evolution. In this work, we investigate the QSL time for multi-qubit open systems. We find that for certain class of states, the memory effect still acts as the indispensable requirement for speeding up quantum evolution, while for another class of states, speedup takes place even when the environment is of no memory. In particular, when the initial state is in product state |111...1>, there exists a sudden transition from no speedup to speedup in memoryless environment. On the other hand, we also display an evidence for the subtle connection between QSL time and entanglement that weak entanglement can accelerate quantum evolution even better.

Chen Liu; Zhen-Yu Xu; Shiqun Zhu

2014-10-30

462

Quantum Metrology in Open Systems: Dissipative Cramér-Rao Bound  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

463

Quantum Metrology in Open Systems: Dissipative Cramér-Rao Bound  

E-print Network

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

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

2014-03-31

464

Distributed algorithms for monitoring and control of electric power transmission and distribution systems  

SciTech Connect

The benefits of distributed computing systems are massively increased computing power and improved reliability. Distributed computing systems are particularly attractive for monitoring and control of large-scale electric power transmission and distribution systems. In this dissertation two aspects of distributed computing have been investigated. First, a distributed software model for the implementation of network security functions in energy management systems is proposed. Second, a theoretical framework for the development of distributed algorithms is developed. The framework is applied to some of the functions necessary for the operation of an automated power distribution system. The proposed distributed model for the software of energy management systems is based on the object-oriented methodology. A prototype implementation of the power flow function is described as a concrete example for the application of the model. Other network security functions discussed are state estimation and bad data detection. The proposed model reduces the effort of development and maintenance of large-scale energy management system software. It provides a tool for coping with the constantly increasing complexity of these software systems. A framework for the development of distributed algorithms is proposed. A special class of separable continuous constrained optimization problems is considered. A class of asynchronous iterative algorithms is developed. The solution of the separable continuous constrained optimization problem is emphasized because many problems arising in the operation of an automated distribution system can be formulated as constrained optimization problems. It is shown that these optimization problems can be solved with a set of largely independent processors which exchange a minimum of information.

Neyer, A.F.

1989-01-01

465

Disentanglement by dissipative open system dynamics  

SciTech Connect

This paper investigates disentanglement as a result of evolution according to a class of master equations which include dissipation and interparticle interactions. Generalizing an earlier result of Diosi, the time taken for complete disentanglement iscalculated (i.e., for disentanglement from any other system). The dynamics of two harmonically coupled oscillators is solved in order to study the competing effects of environmental noise and interparticle coupling on disentanglement. An argument based on separability conditions for Gaussian states is used to arrive at a set of conditions on the couplings sufficient for all initial states to disentangle for good after a finite time.

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

2004-05-01

466

Disentanglement by dissipative open system dynamics  

NASA Astrophysics Data System (ADS)

This paper investigates disentanglement as a result of evolution according to a class of master equations which include dissipation and interparticle interactions. Generalizing an earlier result of Diósi, the time taken for complete disentanglement iscalculated (i.e., for disentanglement from any other system). The dynamics of two harmonically coupled oscillators is solved in order to study the competing effects of environmental noise and interparticle coupling on disentanglement. An argument based on separability conditions for Gaussian states is used to arrive at a set of conditions on the couplings sufficient for all initial states to disentangle for good after a finite time.

Dodd, P. J.

2004-05-01

467

47 CFR 76.1712 - Open video system (OVS) requests for carriage.  

...2014-10-01 2014-10-01 false Open video system (OVS) requests for carriage...BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Documents...Maintained for Inspection § 76.1712 Open video system (OVS) requests for...

2014-10-01

468

47 CFR 76.1712 - Open video system (OVS) requests for carriage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Open video system (OVS) requests for carriage...BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Documents...Maintained for Inspection § 76.1712 Open video system (OVS) requests for...

2013-10-01

469

47 CFR 76.1712 - Open video system (OVS) requests for carriage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Open video system (OVS) requests for carriage...BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Documents...Maintained for Inspection § 76.1712 Open video system (OVS) requests for...

2011-10-01

470

47 CFR 76.1712 - Open video system (OVS) requests for carriage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Open video system (OVS) requests for carriage...BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Documents...Maintained for Inspection § 76.1712 Open video system (OVS) requests for...

2012-10-01

471

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

Code of Federal Regulations, 2010 CFR

...requirements under the Commission's open video system regulations concerning must-carry...including a list of all local commercial and non-commercial television... (2) Information. An open video system operator shall provide...

2010-10-01

472

47 CFR 76.1712 - Open video system (OVS) requests for carriage.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Open video system (OVS) requests for carriage...BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Documents...Maintained for Inspection § 76.1712 Open video system (OVS) requests for...

2010-10-01

473

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

474

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

475

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

476

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

477

Distributed Satellite Communication System Design: First-Order Interactions between System and Network  

E-print Network

Distributed Satellite Communication System Design: First-Order Interactions between System to bankruptcy. The upfront capital required to implement a satellite communications system is staggering and performance of a system. Traditionally, the first step toward designing satellite communication systems

de Weck, Olivier L.

478

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

479

Heat-exchange statistics in driven open quantum systems  

E-print Network

As the dimensions of physical systems approach the nanoscale, the laws of thermodynamics must be reconsidered due to the increased importance of fluctuations and quantum effects. While the statistical mechanics of small classical systems is relatively well understood, the quantum case still poses challenges. Here we set up a formalism that allows to calculate the full probability distribution of energy exchanges between a periodically driven quantum system and a thermalized heat reservoir. The formalism combines Floquet theory with a generalized master equation approach. For a driven two-level system and in the long-time limit, we obtain a universal expression for the distribution, providing clear physical insight into the exchanged energy quanta. We illustrate our approach in two analytically solvable cases and discuss the differences in the corresponding distributions. Our predictions could be directly tested in a variety of systems, including optical cavities and solid-state devices.

S. Gasparinetti; P. Solinas; A. Braggio; M. Sassetti

2014-07-29

480

Heat-exchange statistics in driven open quantum systems  

NASA Astrophysics Data System (ADS)

As the dimensions of physical systems approach the nanoscale, the laws of thermodynamics must be reconsidered due to the increased importance of fluctuations and quantum effects. While the statistical mechanics of small classical systems is relatively well understood, the quantum case still poses challenges. Here, we set up a formalism that allows us to calculate the full probability distribution of energy exchanges between a periodically driven quantum system and a thermalized heat reservoir. The formalism combines Floquet theory with a generalized master equation approach. For a driven two-level system and in the long-time limit, we obtain a universal expression for the distribution, providing clear physical insight into the exchanged energy quanta. We illustrate our approach in two analytically solvable cases and discuss the differences in the corresponding distributions. Our predictions could be directly tested in a variety of systems, including optical cavities and solid-state devices.

Gasparinetti, S.; Solinas, P.; Braggio, A.; Sassetti, M.

2014-11-01

481

Communication synthesis for distributed embedded systems  

Microsoft Academic Search

Abstract: Communication synthesis is an essential step in hardware-software co-synthesis: many embedded systems use custom communication topologies and the communication links are often a significant part of the system cost. This paper describes new techniques for the analysis and synthesis of the communication requirements of embedded systems during co-synthesis. Our analysis algorithm derives delay bounds on communication in the system

Ti-Yen Yen; Wayne Wolf

1995-01-01

482

Power distribution system planning with reliability modeling and optimization  

SciTech Connect

A new approach for the systemized optimization of power distribution systems is presented in this paper. Distribution system reliability is modeled in the optimization objective function via outage costs and costs of switching devices, along with the nonlinear costs of investment, maintenance and energy losses of both the substations and the feeders. The optimization model established is multi-stage, mixed-integer and nonlinear, which is solved by a network-flow programming algorithm. A multi-stage interlacing strategy and a nonlinearity iteration method are also designed. Supported by an extensive database, the planning software tool has been applied to optimize the power distribution system of a developing city.

Tang, Y. [Siemens Power Corp., Roswell, GA (United States)] [Siemens Power Corp., Roswell, GA (United States)

1996-02-01

483

Design of an integrated distribution control system  

Microsoft Academic Search

In an effort to supply electric power at minimum cost, the electric utility industry continues to examine techniques that will allow the power system to operate more effectively and efficiently. In recent years, interest has developed in automated methods to facilitate the planning and operation of electric power systems. These techniques include the Supervisory Control and Data Acquisition system (SCADA)

S. L. Purucker; T. W. Reddoch; J. S. Detwiler; L. D. Monteen

1984-01-01

484

Open loop optimization of a complex steam cogeneration system  

SciTech Connect

For years power engineers have dreamed of the day when they could perform on-line or even near on-line optimization of complicated steam cogeneration systems. Early attempts at using linear programming achieved some success, but linear programming does not provide for complete closure of the system`s heat balance. Tennessee Eastman Division of Eastman Chemical Co. operates a steam system comprised of 24 boilers and 19 steam turbine generators. In the Fall of 1995 a near on-line, open loop optimization system was placed into initial testing. This system uses a heat balance model coupled with an optimizer employing a non-linear programming algorithm. This paper will discuss the development and installation of the system and will review some of the results that have been achieved.

Clary, A.T. [Eastman Chemical Co., Kingsport, TN (United States). Tennessee Eastman Div.

1996-12-31

485

Hall conductance and topological invariant for open systems  

PubMed Central

The Hall conductivity given by the Kubo formula is a linear response of quantum transverse transport to a weak electric field. It has been intensively studied for quantum systems without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formulism to deal with this issue for topological insulators. The Hall conductance of a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory developed for open systems in this paper. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed. PMID:25248375

Shen, H. Z.; Wang, W.; Yi, X. X.

2014-01-01

486

Hall conductance and topological invariant for open systems.  

PubMed

The Hall conductivity given by the Kubo formula is a linear response of quantum transverse transport to a weak electric field. It has been intensively studied for quantum systems without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formulism to deal with this issue for topological insulators. The Hall conductance of a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory developed for open systems in this paper. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed. PMID:25248375

Shen, H Z; Wang, W; Yi, X X

2014-01-01

487

Hall conductance and topological invariant for open systems  

NASA Astrophysics Data System (ADS)

The Hall conductivity given by the Kubo formula is a linear response of quantum transverse transport to a weak electric field. It has been intensively studied for quantum systems without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formulism to deal with this issue for topological insulators. The Hall conductance of a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory developed for open systems in this paper. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed.

Shen, H. Z.; Wang, W.; Yi, X. X.

2014-09-01

488

Hall conductance and topological invariant for open systems  

E-print Network

The Hall conductivity given by the Kubo formula is a linear response of the quantum transverse transport to a weak electric field. It has been intensively studied for a quantum system without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formalism to deal with this issue for topological insulators. The Hall conductance for a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory of open system. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed.

H. Z. Shen; W. Wang; X. X. Yi

2014-10-07

489

Securing Dynamic Distributed Storage Systems Against Eavesdropping and Adversarial Attacks  

Microsoft Academic Search

We address the problem of securing distributed storage systems against eavesdropping and adversarial attacks. An important aspect of these systems is node failures over time, necessitating, thus, a repair mechanism in order to maintain a desired high system reliability. In such dynamic settings, an important security problem is to safeguard the system from an intruder who may come at different

Sameer Pawar; Salim El Rouayheb; Kannan Ramchandran

2011-01-01

490

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

491

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

492

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

493

The Design of an Integrated Distribution Control system  

Microsoft Academic Search

The Athens Automation and Control Experiment, (AACE) F is a major test of automation techniques for electric distribution systems to quantify the benefits and to correlate these capabilities and benefits with bulk power system operations. A key element in the experiment is the design of the hardware\\/software: associated. with the computer, communications, and control system which constitute the automation system.

S. L. Purucker; T. W. Reddoch; J. S. Detwiler; L. D. Monteen

1985-01-01

494

STATE RESTORATION IN DISTRIBUTED SYSTEMS Philip M. MERLIN  

E-print Network

1 STATE RESTORATION IN DISTRIBUTED SYSTEMS Philip M. MERLIN Department of Electrical Engineering error recovery", i.e. restoring a system, or some part of a system, to a previous state which deal of independence between activities, the system can be restored to a state that could have existed

Newcastle upon Tyne, University of

495

Automation of Space Station module power management and distribution system  

NASA Technical Reports Server (NTRS)

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

Bechtel, Robert; Weeks, Dave; Walls, Bryan

1990-01-01

496

A Comparison of Two Distributed Systems: Amoeba and Sprite  

E-print Network

A Comparison of Two Distributed Systems: Amoeba and Sprite [To appear in Computing Systems .] Fred operating systems, Amoeba and Sprite. Although the systems share many goals, they diverged on two) follow from the philosophical differences. For example, Amoeba provides a high­performance user­level IPC

497

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

Code of Federal Regulations, 2012 CFR

...Distribution systems reporting transmission pipelines; transmission or gathering systems reporting distribution pipelines. 191.13 Section 191.13 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...

2012-10-01

498

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

Code of Federal Regulations, 2011 CFR

...Distribution systems reporting transmission pipelines; transmission or gathering systems reporting distribution pipelines. 191.13 Section 191.13 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...

2011-10-01

499

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

Code of Federal Regulations, 2013 CFR

...Distribution systems reporting transmission pipelines; transmission or gathering systems reporting distribution pipelines. 191.13 Section 191.13 Transportation...Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...

2013-10-01

500

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