Note: This page contains sample records for the topic open distributed systems from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Resonance width distribution for open quantum systems  

NASA Astrophysics Data System (ADS)

Recent measurements of resonance widths for low-energy neutron scattering off heavy nuclei show large deviations from the Porter-Thomas distribution. We propose a “standard” width distribution based on the random matrix theory for a chaotic quantum system with a single open decay channel. Two methods of derivation lead to a single analytical expression that recovers, in the limit of very weak continuum coupling, the Porter-Thomas distribution. The parameter defining the result is the ratio of typical widths ? to the energy level spacing D. Compared to the Porter-Thomas distribution, the new distribution suppresses small widths and increases the probabilities of larger widths. We show also that it is necessary to take into account the ? channels.

Shchedrin, Gavriil; Zelevinsky, Vladimir

2012-10-01

2

Towards secure dataflow processing in open distributed systems  

Microsoft Academic Search

Open distributed systems such as service oriented architecture and cloud computing have emerged as promising platforms to deliver software as a service to users. However, for many security sen- sitive applications such as critical data processing, trus t manage- ment poses significant challenges for migrating those criti cal ap- plications into open distributed systems. In this paper, we present the

Juan Du; Wei Wei; Xiaohui Gu; Ting Yu

2009-01-01

3

Architecture for Open Distributed Software Systems  

Microsoft Academic Search

Distributed applications consist of discrete software components which are spread across multiple systems. The interaction between these components constitutes distrib- uted processing. If the discrete components are capable of exhibiting \\

Kazi Farooqui; Luigi Logrippo

1996-01-01

4

Architectural Support for Designing Fault-Tolerant Open Distributed Systems  

Microsoft Academic Search

An overview of the main techniques for designing fault-tolerant software and hardware systems is provided. The important features of the building blocks (computers, memories, buses, etc.) that can support an efficient implementation of fault-tolerant open distributed systems (FTODSs) are identified. Taking into account the features of these building blocks, an organization for FTODS is proposed. A distributed voting algorithm and

Salim Hariri; Alok N. Choudhary; Behçet Sarikaya

1992-01-01

5

An open design approach for distributed energy management systems  

Microsoft Academic Search

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

Liam Murphy; Felix F. Wu

1993-01-01

6

Wigner Distribution Function for Open Quantum Systems  

Microsoft Academic Search

Using the modified biorthonormal Heisenberg equations of motion for non-Hermitian (NH) Hamilton operators, in order to imply a consistent Lie-algebraic structure and also the equivalence between the Heisenberg and Schrödinger pictures, we have obtained the analytical form of the Wigner distribution function which is unavoidable complex. Its imaginary part accounts for the influence of additional degrees of freedom, which are

S. Baskoutas

1997-01-01

7

Role Signatures for Access Control in Open Distributed Systems  

Microsoft Academic Search

Implementing access control efficiently and effectively in an open and distributed system is a challenging problem. One reason for this is that users re- questing access to remote resources may be unknown to the authorization service that controls access to the requested resources. Hence, it seems inevitable that pre- defined mappings of principals in one domain to those in the

Jason Crampton; Hoon Wei Lim

2008-01-01

8

Defining Policies for Performance Management in Open Distributed Systems  

Microsoft Academic Search

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

B. Meyer; C. Popien

1994-01-01

9

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

10

Equilibrium Distributions in Open and Closed Statistical Systems  

Microsoft Academic Search

In this communication, the derivation of the Boltzmann-Gibbs and the Maxwellian distributions is presented from a geometrical point of view under the hypothesis of equiprobability. It is shown that both distributions can be obtained by working out the properties of the volume or the surface of the respective geometries delimited in phase space by an additive constraint. That is, the

Ricardo Lopez-Ruiz; Jaime Sanudo; Xavier Calbet

2010-01-01

11

Construction and management of highly available services in open distributed systems  

Microsoft Academic Search

The paper addresses the problem of the construction and management of highly available services in large, open distributed systems. A novel replication protocol is proposed to satisfy two fundamental requirements, in this environment: 1) hide replication from the service clients; 2) facilitate the dynamic configuration management of the server group. The protocol has been implemented and tested in the Regis

Christos T. Karamanolis; Jeff Magee

1998-01-01

12

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

13

Developing Simulation Models of Open Distributed Control System by Using Object-Oriented Structural and Behavioral Patterns  

Microsoft Academic Search

An open distributed control system (DCS), which consists of many devices and an open network interconnecting them, is now used in many automation areas. For assuring the control performance under the heavy traffic on the network, the simulation of a DCS is strongly needed. For this purpose, we propose an object- oriented design pattern approach as a uniform, efficient and

Toyoaki Tomura; Satoshi Kanai; S. Yamamoto

2001-01-01

14

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

15

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

16

Measurement of tracer gas distributions using an open-path FTIR system coupled with computed tomography  

Microsoft Academic Search

Optical remote sensing and iterative computed tomography (CT) can be combined to measure the spatial distribution of gaseous pollutant concentrations in a plane. We have conducted chamber experiments to test this combination of techniques using an Open Path Fourier Transform Infrared Spectrometer (OP-FTIR) and a standard algebraic reconstruction technique (ART). ART was found to converge to solutions that showed excellent

Anushka C. Drescher; Michael G. Yost; Doo Y. Park; Steven P. Levine; Ashok J. Gadgil; Marc L. Fischer; William W. Nazaroff

1995-01-01

17

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

18

The Saga Security System: A Security Architecture for Open Distributed Systems  

Microsoft Academic Search

In the paper we present an overview of Saga Security System,a security architectureinopen distributedsystems. An agent in Saga Security System is called a Saga Agent. The authorization model in Saga Security System (Saga authorization model)supportsthenovelconceptofa service path and provides uniform and flexible protection appro- priate for advanced computational models such as object- oriented systems and cooperative agent systems. With re-

Masakazu Soshi; Mamoru Maekawa

1997-01-01

19

Methane generation from coal during open system pyrolysis investigated by isotope specific, Gaussian distributed reaction kinetics  

Microsoft Academic Search

A reaction kinetic model is presented to differentiate individual complexes of reactions of the thermal decomposition of sedimentary organic matter during pyrolysis experiments. This model is applied to methane generation from coal during open system pyrolysis experiments with linear heating. The reaction kinetic model is based on the concept of a certain number of reaction complexes contributing to the generation

Bernhard Cramer

2004-01-01

20

Vapor Nucleation and Droplet Growth: Cluster Distribution Kinetics for Open and Closed Systems  

Microsoft Academic Search

A theory based on cluster distribution kinetics for single-monomer addition and dissociation is presented as a framework for homogeneous and heterogeneous vapor nucleation and growth dynamics. For continuous cluster and monomer distributions in a well-mixed non-steady-state flow system, population (mass) balance equations yield moment equations for the cluster mass moments. Nuclei are either homogeneously generated or heterogeneously seeded, and subsequent

Benjamin J. McCoy

2000-01-01

21

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

22

Silfide: A System for Open Access and Distributed Delivery of TEI Encoded Documents  

Microsoft Academic Search

This paper presents some aspects of the Silfide server, a system dedicated to the delivery of linguistic resources on the web. After presenting the main issues behind the design of such a system, we focus on the editorial choices related to the use of the Text Encoding Initiative to represent our textual documents. In particular, we focus on the accommodations

Laurent Romary; Patrice Bonhomme; Florence Bruneseaux; Jean-Marie Pierrel

1999-01-01

23

[The future of telepathology. An Internet "distributed system" with "open standards"].  

PubMed

With the availability of Internet, the interest in the possibilities of telepathology has increased considerably. In the foreground is thereby the need of the non-expert to bring in the opinions of experts on morphological findings by means of a fast and simple procedure. The new telepathology system iPath is in compliance with these needs. The system is based on small, but when possible independently working modules. This concept allows a simple adaptation of the system to the individual environment of the user (e.g. for different cameras, frame-grabbers, microscope steering tables etc.) and for individual needs. iPath has been in use for 6 months with various working groups. In telepathology a distinction is made between "passive" and "active" consultations but for both forms a non-expert brings in the opinion of an expert. In an active consultation both are in direct connection with each other (orally or via a chat-function), this is however not the case with a passive consultation. An active consultation can include the interactive discussion of the expert with the non-expert on images in an image database or the direct interpretation of images from a microscope by the expert. Four software modules are available for a free and as fast as possible application: (1) the module "Microscope control", (2) the module "Connector" (insertion of images directly from the microscope without a motorized microscope), (3) the module "Client-application" via the web-browser and (4) the module "Server" with a database. The server is placed in the internet and not behind a firewall. The server permanently receives information from the periphery and returns the information to the periphery on request. The only thing which the expert, the non-expert and the microscope have to know is how contact can made with the server. PMID:12089787

Brauchli, K; Helfrich, M; Christen, H; Jundt, G; Haroske, G; Mihatsch, M; Oberli, H; Oberholzer, M

2002-05-01

24

of Performance Models for Distributed Application Systems  

Microsoft Academic Search

Organizations have become increasingly dependent on computing systems to achieve their business goals. The performance of these systems in terms of response times and cost has a major impact on their effectiveness. To achieve openness and scalability, these systems have begun to rely on distributed environment technologies such as the Open Software Foundation's Distributed Computing Environment (DCE) and the Object

M. Qin; R. Lee; A. El Rayess; V. Vetland; J. Rolia

25

An Architecture for Operating System Support of Distributed Multimedia Systems  

Microsoft Academic Search

Distributed multimedia applications introduce new design challenges at all systems levels from network protocols and operating systems to application support platforms. The paper describes an object-oriented architecture integrating network services with the operating system to support distributed multimedia systems. The architecture, called Dynamic Object Architecture (DOA), is based on Open Distributed Processing (ODP), the international standard on distributed system and

Ya Xu; Cyril U. Orji; Yi Deng; Naphtali Rishe

1995-01-01

26

The Open Systems University.  

ERIC Educational Resources Information Center

The purpose of this paper is focused toward a systems understanding of the contemporary university, the American University being the data base. A general systems conceptualization called the open systems university is presented. Comprehensive and generic in character, it is hoped that the theory of the open university will be viable enough to…

Counelis, James Steve

27

Distributed computer control systems  

Microsoft Academic Search

This book focuses on recent advances in the theory, applications and techniques for distributed computer control systems. Contents (partial): Real-time distributed computer control in a flexible manufacturing system. Semantics and implementation problems of channels in a DCCS specification. Broadcast protocols in distributed computer control systems. Design considerations of distributed control architecture for a thermal power plant. The conic toolset for

Suski

1986-01-01

28

Local oscillator fluctuation opens a loophole for Eve in practical continuous-variable quantum-key-distribution systems  

NASA Astrophysics Data System (ADS)

We consider the security of practical continuous-variable quantum-key-distribution implementation with the local oscillator (LO) fluctuating in time, which opens a loophole for Eve to intercept the secret key. We show that Eve can simulate this fluctuation to hide her Gaussian collective attack by reducing the intensity of the LO. Numerical simulations demonstrate that if Bob does not monitor the LO intensity and does not scale his measurements with the instantaneous intensity values of LO, the secret key rate will be compromised severely.

Ma, Xiang-Chun; Sun, Shi-Hai; Jiang, Mu-Sheng; Liang, Lin-Mei

2013-08-01

29

Ground fault and overcurrent protection criteria for coal mine AC distribution systems. Open file report August 1979-October 1980  

SciTech Connect

Ground fault and overcurrent protection criteria for coal mine ac distribution systems were examined by authorization of the Bureau of Mines. The report begins with a literature review that discusses relaying topics including instrument transformers, ground fault pickup methods, static relaying, and comparison of relaying techniques. A chapter on ground fault relaying provides recommendations for maximum and minimum pickup levels as a function of maximum ground current and power system line-to-ground capacitance. Research in the area of phase overcurrent protection has resulted in a complete set of procedural recommendations for the selection and setting of overcurrent relays and current transformers, molded-case circuit breakers, and distribution system fuses in coal mine power systems. The final chapter discusses relay system maintenance and introduces a unique test set that is used to test the performance of relaying systems in coal mines.

Kiefer, J.A.; Kohler, J.L.

1980-10-31

30

A Framework for Open, Flexible and Distributed Learning.  

ERIC Educational Resources Information Center

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

Khan, Badrul H.

31

Secure Distributed File Systems.  

National Technical Information Service (NTIS)

Secure information distribution is a strategic capability as significant as weapons systems and tactics to military operations. The Department of Defense has recognized the importance of establishing and maintaining secure distributed file systems and exp...

T. M. Conroy W. H. Buxton

1994-01-01

32

Monitoring distributed systems  

Microsoft Academic Search

The monitoring of distributed systems involves the collection, interpretation, and display of information concerning the interactions among concurrently executing processes. This information and its display can support the debugging, testing, performance evaluation, and dynamic documentation of distributed systems. General problems associated with monitoring are outlined in this paper, and the architecture of a general purpose, extensible, distributed monitoring system is

Jeffrey Joyce; Greg Lomow; Konrad Slind; Brian Unger

1987-01-01

33

Distributed operating systems  

Microsoft Academic Search

Distributed operating systems have many aspects in common with centralized ones, but they also differ in certain ways. This paper is intended as an introduction to distributed operating systems, and especially to current university research about them. After a discussion of what constitutes a distributed operating system and how it is distinguished from a computer network, various key design issues

Andrew S. Tanenbaum; Robbert Van Renesse

1985-01-01

34

Ground fault and overcurrent protection criteria for coal mine AC distribution systems. Open file report August 1979October 1980  

Microsoft Academic Search

Ground fault and overcurrent protection criteria for coal mine ac distribution systems were examined by authorization of the Bureau of Mines. The report begins with a literature review that discusses relaying topics including instrument transformers, ground fault pickup methods, static relaying, and comparison of relaying techniques. A chapter on ground fault relaying provides recommendations for maximum and minimum pickup levels

J. A. Kiefer; J. L. Kohler

1980-01-01

35

Trust Management in Open Systems (TMOS).  

National Technical Information Service (NTIS)

Distributed software subjects face the problem of determining one another's trustworthiness. The problem considered in the Trust Management in Open Systems (TMOS) project is management of the exchange of sensitive credentials between strangers for the pur...

V. E. Jones W. H. Winsborough K. Seamons

2002-01-01

36

Open systems and databases  

SciTech Connect

This paper is part of a series of papers invited by the IEEE POWER CONTROL CENTER WORKING GROUP concerning the changing designs of modern control centers. Papers invited by the Working Group discuss the following issues: Benefits of Openness, Criteria for Evaluating Open EMS Systems, Hardware Design, Configuration Management, Security, Project Management, Databases, SCADA, Inter- and Intra-System Communications and Man-Machine Interfaces,'' The goal of this paper is to provide an introduction to the issues pertaining to Open Systems and Databases.'' The intent is to assist understanding of some of the underlying factors that effect choices that must be made when selecting a database system for use in a control room environment. This paper describes and compares the major database information models which are in common use for database systems and provides an overview of SQL. A case for the control center community to follow the workings of the non-formal standards bodies is presented along with possible uses and the benefits of commercially available databases within the control center. The reasons behind the emergence of industry supported standards organizations such as the Open Software Foundation (OSF) and SQL Access are presented.

Martire, G.S. (ECC, Inc., Fairfax, VA (United States)); Nuttall, D.J.H. (Unified Information, Inc., Kirkland, WA (United States))

1993-05-01

37

Hadoop distributed file system for the Grid  

Microsoft Academic Search

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

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

2009-01-01

38

Open quantum systems  

Microsoft Academic Search

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

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

2004-01-01

39

Open standard development platforms for distributed sensor networks  

NASA Astrophysics Data System (ADS)

In the development of distributed security sensor networks a large variety of prototype systems have been implemented and tested. However these systems tend to be developer specific and require substantial overhead in demonstrating more than one application. To bridge the gap between embedded, networked systems and desktop simulation environments, systems are necessary which are easily deployable and allow extended operation of distributed sensor networks, while allowing the flexibility to quickly test and evaluate a variety of operational algorithms. To enable fast optimization by leveraging the widest development community, open standards for such a portable development system are desired. An open development system allows individual developers and small groups to focus on and optimize specific aspects of a distributed sensor network within realistic deployment constraints, prior to complete integration and deployment of a system within a specific application. By providing an embedded sensor and processing platform with integrated wired and wireless networking, a modular software suite separating access and control of individual processes, and open APIs, algorithm development and software optimization can be greatly accelerated and more robustly tested. To meet the unique needs of distributed sensor network applications, additional separation must be provided between the access to various subsystems, for example real-time embedded control versus tasks with less stringent timing requirements. An open platform that separates these requirements allows developers to accelerate testing and development of applications by focusing on individual components of the distributed sensor system, such as target tracking or low power networking. The WINS NG 2.0 developer's platform, provided by Sensoria Corporation for the DARPA/ITO Sensor Information Technology (SensIT) program, provides one example of such a system. This systems bridge the gap between dedicated desktop development environments and embedded application-specif

Merrill, William; Sohrabi, Katayoun; Girod, Lewis; Elson, Jeremy; Newberg, Fredric; Kaiser, William J.

2002-08-01

40

Forecasting of open system behaviour  

Microsoft Academic Search

Two dynamic models of the forecasted behaviour of an open thermodynamic system under given expected variations in the open system behaviour have been obtained. The two dynamic models have been presented as two machines. Each machine is made up of a closed system, which is obtained from the open one by isolation, and an environment. The first machine is driven

S. Z. Stefanov

1997-01-01

41

Secure software distribution system  

SciTech Connect

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

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

1997-02-01

42

Security for distributed systems  

Microsoft Academic Search

This article is an introduction to the subject of security in distributed systems. It is assumed that the reader is generally familiar with the concepts of computer and communications security, by which we mean protection against risks which can compromise data integrity, allow unauthorised disclosure of information or lead to denial of service in systems. However, this article aims to

Peter Trueman

1986-01-01

43

Simplifying Distributed System Development  

Microsoft Academic Search

Distributed systems are difficult to design and develop. The difficulties arise both in basic safety correctness properties, as well as in achieving high performance. As a result of this complexity, the implementation of a dis- tributed system often contains the basic algorithm cou- pled with an embedded strategy for making choices, such as the choice of a node to interact

Maysam Yabandeh; Nedeljko Vasi; Dejan Kosti; Viktor Kuncak

44

Minimum Loss Configuration of Power Distribution System  

Microsoft Academic Search

This paper presents a new method for minimum loss reconfiguration for radial power distribution system, in which the choice of the switches to be opened \\/ closed is based on the calculation of voltage at the buses, real and reactive power flowing through lines, real power losses and voltage deviation, using distribution load flow (DLF) program. In the process of

Jaswanti; T. Thakur

2006-01-01

45

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

46

Factors Affecting Distributed System Security.  

National Technical Information Service (NTIS)

Recent work examining distributed system security requirements is critiqued. A notion of trust based on distributed system topology and distributed system node evaluation levels proposed in that work is shown to be deficient. The notion fails to make allo...

D. M. Nessett

1985-01-01

47

Automatic generation of performance models for distributed application systems  

Microsoft Academic Search

Organizations have become increasingly dependent on computing systems to achieve their business goals. The performance of these systems in terms of response times and cost has a major impact on their effectiveness. To achieve openness and scalability, these systems have begun to rely on distributed environment technologies such as the Open Software Foundation's Distributed Computing Environment (DCE) and the Object

M. Qin; R. Lee; Asham El Rayess; Vidar Vetland; Jerome A. Rolia

1996-01-01

48

Open Systems Approach to Supportability.  

National Technical Information Service (NTIS)

The open systems approach is both a technical approach to weapons systems engineering and a preferred business strategy that is becoming widely applied by manufacturers of large complex systems. Today, legacy systems continue to be developed with their ow...

A. G. Larson C. K. Banning J. F. Leonard

2002-01-01

49

Game Models for Open Systems.  

National Technical Information Service (NTIS)

An open system is a system whose behavior is jointly determined by its internal structure and by the input it receives from the environment. To solve control and verification problem open systems have often been modeled as games between the System and the...

L. de Alfaro

2006-01-01

50

Distributed spot pricing in radial distribution systems  

Microsoft Academic Search

Spot pricing is a method for pricing electricity that maximizes the economic efficiency of the power system. The authors derive an expression for the spot prices in a radial distribution system, in terms of system quantities such as power line flows. The system's radial structure leads to simplified spot price expressions. They do not assume that all the problem data

L. Murphy; R. J. Kaye; F. F. Wu

1994-01-01

51

Integrated luminosity distribution of Galactic open clusters  

NASA Astrophysics Data System (ADS)

The luminosity distribution of a sample of 221 Galactic open clusters has been derived from the integrated cluster parameters in order to study the cluster formation and history. Emphasis is given to the sharp cutoff at I(Mv) = -2.0 m; it is concluded that the cutoff is not due only to selection effects. The surface density of the clusters for different magnitude intervals is obtained along with a relation between I(Mv) and surface density which yields a steeper slope than that obtained by van den Bergh and Lafontaine (1984).

Bhatt, B. C.; Pandey, A. K.; Mahra, H. S.

1991-09-01

52

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

53

OpenSkies: a commercial 3D distributed visualization and simulation toolkit  

Microsoft Academic Search

A growing need for more advanced training capabilities and the proliferation of government standards into the commercial market has inspired Cybernet to create an advanced, distributed 3D Simulation Toolkit. This system, called OpenSkies, is a truly open, realistic distributed system for 3D visualization and simulation. One of the main strengths of OpenSkies is its capability for data collection and analysis.

Paul N. Cobb; Charles J. Jacobus; Douglas Haanpaa

2000-01-01

54

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

SciTech Connect

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

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

2011-06-28

55

Distributed fuzzy system modeling  

SciTech Connect

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

Pedrycz, W.; Chi Fung Lam, P.; Rocha, A.F. [Univ. of Manitoba, Winnipeg, Manitoba (Canada)

1995-05-01

56

Distributed Simulation Using Distributed Control Systems  

Microsoft Academic Search

Modern process automation and control systems must bo able to control discrete as well as continuous events. These events are sensed and controlled by distributed devices. Simulation is a necessity in order tct design and tune the automatic control system. This paper addresses the advantages and disadvantages of using the discrete and continuous functions available in the control system to

Morton W. Reed; PED PE

1990-01-01

57

Distributed simulation using distributed control systems  

Microsoft Academic Search

Modern process automation and control systems must be able to control discrete as well as continuous events. These events are sensed and controlled by distributed devices. Simulation is a necessity in order to design and tune the automatic control system. This paper addresses the advantages and disadvantages of using the discrete and continuous functions available in the control system to

Morton W. Reed

1990-01-01

58

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.

Skogmo, David (Albuquerque, NM)

1997-01-01

59

Open-PEA Space Charge Measurement System  

NASA Astrophysics Data System (ADS)

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

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

60

Distributed Power System for Microsatellites.  

National Technical Information Service (NTIS)

The Aerospace Corporation has independently developed a distributed 'Ring Bus' electric power system for Picosatellites. This distributed power system architecture is being implemented on a number of upcoming Picosatellite missions. The first implementati...

E. J. Simburger D. Rumsey D. Hinkley S. Liu P. Carian

2004-01-01

61

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

62

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

63

Smart system for distributed sensing  

Microsoft Academic Search

This paper describes ongoing work for implementing a distributed multi-robot system for measuring various physical properties of the environment in a coordinated manner. Modeling spatial distributions of physical quantities such as temperature, illumination, humidity, gas concentrations, or magnetic flux provides an opportunity to observe how these distributions change in time, how to utilise the information captured by the distributions, and

Juha Röning; Janne Haverinen; Anssi Kemppainen; Henna Mörsäri; Ilari Vallivaara

2008-01-01

64

Reliability Analysis in Distributed Systems  

Microsoft Academic Search

Reliability of a distributed processing system is an important design parameter that can be described in terms of the reliability of processing elements and communication links and also of the redundancy of programs and data files. The traditional terminal-pair reliability does not capture the redundancy of programs and files in a distributed system. Two reliability measures are introduced: distributed program

Cauligi S. Raghavendra; Viktor K. Prasanna; Salim Hariri

1988-01-01

65

DISTRIBUTION SYSTEM CONSIDERATIONS FOR TREATMENT  

EPA Science Inventory

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

66

Recent development in open systems for EMS\\/SCADA  

Microsoft Academic Search

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

Yutaka Kokai; Fumio Masuda; Satoshi Horiike; Yasuji Sekine

1998-01-01

67

Distributed Modular Computer-Integrated Surgical Robotic Systems: Implementation Using Modular Software and Networked Systems  

Microsoft Academic Search

We seek to build CIS research systems within a flexible, open architecture. In this paper, we outline our solutions to the problems of system design, construction, and integration in this environment: building distributed, modular systems for sensing, control, and processing. Based on our experience building these systems, we utilize distributed network architectures, modular software components, and intelligent object distribution to

Andrew Bzostek; Rajesh Kumar; Nobuhiko Hata; Oliver Schorr; Ron Kikinis; Russell H. Taylor

2000-01-01

68

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

69

ANN - based distribution system reconfiguration  

SciTech Connect

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

Momoh, J.A.; Wang, Yanchun [Howard Univ., Washington, DC (United States). Electrical Engineering Dept.; Rizy, D.T. [Oak Ridge National Lab., TN (United States)

1997-08-01

70

Constructing Distributed Systems in Conic  

Microsoft Academic Search

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

Jeff Magee; Jeff Kramer; Morris Sloman

1989-01-01

71

Effective factor endowments, trade openness and income distribution in China  

Microsoft Academic Search

This paper studies the empirical relationship among factor endowment, trade openness and individual income distribution. Using\\u000a panel data, we show that factor endowment characters, to some extent, explains income gap in China. First, land and Capital\\u000a intensive provinces have a more equal income distribution while human capital and labor-intensive provinces have a less equal\\u000a income distribution. Second, Trade openness has

Xiaodong Lu; Guowei Cai

2011-01-01

72

Open Forum: The Future of Library Systems  

Microsoft Academic Search

Moderated by Maria Collins of North Carolina State University, discussion at this open forum on the future of library systems touched on open-source library systems, cloud computing, new initiatives by the Open Library Environment (OLE) Project and OCLC, and desired characteristics of future integrated library systems. Most participants had limited experience with next-generation library systems and attended the open forum

Maria Collins; Andrée J. Rathemacher

2010-01-01

73

Open Systems and Citizenship: Designing a Departmental Web Site as an Open System.  

ERIC Educational Resources Information Center

|Describes how members of the English Department at Texas Tech University redesigned their site as an open system in which control is distributed among department members. Describes the conversational approach they used to redesign the site, applies it to a critique of the original web site, then describes changes they implemented to remake the…

Spinuzzi, Clay; Bowie, Jennifer L.; Rodgers, Ida; Li, Xiangyi

2003-01-01

74

OpenSkies: a commercial 3D distributed visualization and simulation toolkit  

NASA Astrophysics Data System (ADS)

A growing need for more advanced training capabilities and the proliferation of government standards into the commercial market has inspired Cybernet to create an advanced, distributed 3D Simulation Toolkit. This system, called OpenSkies, is a truly open, realistic distributed system for 3D visualization and simulation. One of the main strengths of OpenSkies is its capability for data collection and analysis. Cybernet's Data Collection and Analysis Environment is closely integrated with OpenSkies to produce a unique, quantitative, performance-based measurement system. This system provides the capability for training students and operators on any complex equipment or system that can be created in a simulated world. OpenSkies is based on the military standard HLA networking architecture. This architecture allows thousands of users to interact in the same world across the Internet. Cybernet's OpenSkies simulation system brings the power and versatility of the OpenGL programming API to the simulation and gaming worlds. On top of this, Cybernet has developed an open architecture that allows the developer to produce almost any kind of new technique in their simulation. Overall, these capabilities deliver a versatile and comprehensive toolkit for simulation and distributed visualization.

Cobb, Paul N.; Jacobus, Charles J.; Haanpaa, Douglas

2000-05-01

75

Dynamic Configuration for Distributed Systems  

Microsoft Academic Search

Dynamic system configuration is the ability to modify and extend a system while it is running. The facility is a requirement in large distributed systems where it may not be possible or economic to stop the entire system to allow modification to part of its hardware or software. It is also useful during production of the system to aid incremental

Jeff Kramer; Jeff Magee

1985-01-01

76

Standard Data Exchanges for Distribution System Management  

SciTech Connect

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

Thomas E. McDermott

2007-10-05

77

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

78

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

79

Open-Source Software Development and Distributed Innovation  

Microsoft Academic Search

Open-source software development is a production model that exploits the distributed intelligence of participants in Internet communities. This model is efficient because of two related reasons: it avoids the inefficiencies of a strong intellectual property regime and it implements concurrently design and testing of software modules. The hazard of open source is that projects can 'fork' into competing versions. However,

Bruce Kogut; Anca Metiu

2001-01-01

80

Arachne Distributed Operating System.  

National Technical Information Service (NTIS)

Arachne is multicomputer operating system implemented at the University of Wisconsin that allows a network of microcomputers to cooperate to provide a general-purpose computing facility. After presenting an overview of the structure of Arachne, this paper...

R. A. Finkel M. H. Solomon

1981-01-01

81

Policy Service for Distributed Systems  

Microsoft Academic Search

The ever-increasing size and complexity of large distributed systems makesmanagement of such systems very difficult. This thesis describes a novel policynotation supported by a policy service which permits flexible evolution ofthe management system. Policies define the overall strategy of the managementsystem and hence influence its behaviour. The policies are interpretedby management agents and so can be easily modified or changed

Damian A. Marriott

1997-01-01

82

Change management of distributed systems  

Microsoft Academic Search

One of the major challenges in the use of distributed computing systems is the accomodation of evolutionary change. Systems evolve as human needs change, technology changes and the application environment changes. These changes may require modification of a function already provided by the system, or extension by the introduction of new functions. In general, evolutionary changes are difficult to accomodate

Jeff Kramer; Jeff Magee

1988-01-01

83

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

84

Small smart distributed control system  

Microsoft Academic Search

This paper presents a small-scale smart distributed control system (DCS) based on the RS-485 network. It discusses the network construction of the distributed control system, the characteristics of RS-485, how to construct a typical RS-485 two wire multi-drop network and the details of the communication protocol. The smart controller based on dual MCUs can execute many kinds of advanced control

Yirong Yang; Shanan Zhu

2002-01-01

85

Distributed computer emulation: Using OpenCL framework  

Microsoft Academic Search

The idea of distributed computer emulation is presented within this paper. Since classic emulation techniques put the power load on the host CPU only, the new approach tries to distribute the load among other available processors within the host platform. The implementation uses OpenCL framework. This standard allows writing high parallel and portable programs in ISO C99 subset language, runnable

Peter Jakubco; Norbert Adam; Eva Dankova

2011-01-01

86

Automated distribution fault locating system  

SciTech Connect

An automated fault locating system (FLS) was designed and implemented for the Colorado River Agency (CRA) 12.5/7.2-kV distribution system. This FLS was integrated into the supervisory control and data acquisition (SCADA) system which was installed at a hydropower plant. This FLS offers several benefits to the CRA distribution system. These benefits include reduced outage time, help in locating momentary faults, enhanced safety to the line crews, provide notification of an outage without receiving calls from the consumer, and decreased overtime.

Hager, G.E. [Electrical Systems Consultants Inc., Fort Collins, CO (United States); Medicine Bear, R.N. [City of Aztec, NM (United States); Baum, A.S. [Scipar Inc., Buffalo, NY (United States)

1996-05-01

87

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

88

Moving Open Access to Open Source: Transitioning an Open-Access Journal into the Open Journal Systems Journal Management System  

Microsoft Academic Search

From 1994 to 2008, the University of Idaho Library published the Electronic Green Journal, a peer-reviewed, cross-disciplinary, open-access journal on environmental issues. In 2007 the editorial board decided to transition the journal into the Open Journal Systems open-source journal-management system. The new system had to be customized, back issues had to be imported, and the editorial board had to be

Ben Hunter

2010-01-01

89

The Echo Distributed File System  

Microsoft Academic Search

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

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

90

A New Heuristic Reconfiguration Algorithm for Large Distribution Systems  

Microsoft Academic Search

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

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

2005-01-01

91

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

92

DASH -- Distributed Analysis System Hierarchy  

NASA Astrophysics Data System (ADS)

DASH is a distributed data reduction and analysis system constructed on CORBA. It plays an important role in the SUBARU computer system not only as an offline analysis system but also as a test and development environment of online quick analysis. We abstracted an object from astronomical data reduction/analysis procedures; `PROCube' (data reduction PROcedure Cube) and implemented it, so that we could share and reuse the reduction procedure. We are also trying to make it possible to retrieve sufficient original data for an analysis semi-automatically in cooperation with SUBARU data archive system (STARS).

Yagi, Masafumi; Mizumoto, Yoshihiko; Nishihara, Eiji; Yoshida, Michitoshi; Asai, Ryo; Chikada, Yoshihiro; Kosugi, George; Takata, Tadafumi; Ogasawara, Ryusuke; Ishihara, Yasuhide; Yanaka, Hiroshi; Morita, Yasuhiro; Nakamoto, Hiroyuki

93

Structuring Mechanisms in Distributed Systems.  

National Technical Information Service (NTIS)

The paper reviews some of the basic structuring mechanisms in distributed systems from the perspective of an wide-accepted reference model (ISO/OSI). The acceptance of the model and its related standards by international bodies (ISO, IEEE, CCITT, IEC etc....

R. Popescu-Zeletin

1985-01-01

94

WATER QUALITY MODELING DISTRIBUTION SYSTEMS  

EPA Science Inventory

This paper reviews the use of models for predicting water quality in distribution systems. esults of an extensive field study conducted by the USEPA and North Penn Mater Authority are examined. A case study of the model application to a waterborne disease outbreak in Cabool, Miss...

95

Voting mechanisms in distributed systems  

Microsoft Academic Search

It is shown how voting mechanisms can be exploited to improve the reliability of decisions in a distributed system. A model of decision making in which several processors (nodes) are assigned to work independently on various aspects of a problem and each returns a binary answer to a coordinator node is assumed. The coordinator combines the answers, using a voting

A. Kumar; K. Malik

1991-01-01

96

DISTRIBUTER - The distributed system for efficient execution of parallel programs  

Microsoft Academic Search

We developed the distributed system called “Distributer” in order to make use of millions of unused CPU cycles inside the LAN. The system is based on server-client architecture and the interaction with the system is implemented via web interface on the server side. Clients connect to server and periodically update their status based on which server distributes and sends jobs

Domagoj Matijevic; Petar Taler; Goran Martinovic

2010-01-01

97

Quasiequilibria in open quantum systems  

SciTech Connect

In this work, the steady-state or quasiequilibrium resulting from periodically modulating the Liouvillian of an open quantum system, L-circumflex-circumflex(t), is investigated. It is shown that differences between the quasiequilibrium and the instantaneous equilibrium occur due to nonadiabatic contributions from the gauge field connecting the instantaneous eigenstates of L-circumflex-circumflex(t) to a fixed basis. These nonadiabatic contributions are shown to result in an additional rotation and/or depolarization for a single spin-1/2 in a time-dependent magnetic field and to affect the thermal mixing of two coupled spins interacting with a time-dependent magnetic field.

Walls, Jamie D. [Department of Chemistry, University of Miami, Coral Gables, Florida 33124 (United States)

2010-03-15

98

Current Distribution in a Plasma Erosion Opening Switch.  

National Technical Information Service (NTIS)

The current distribution in a plasma erosion opening switch is determined from magnetic field probe data. During the closed state of the switch the current channel broadens rapidly. The width of the current channel is consistent with a bipolar current den...

B. V. Weber R. J. Commisso R. A. Meger J. M. Neri W. F. Oliphant

1985-01-01

99

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

100

The CEBAF Frequency Distribution System  

SciTech Connect

The RF system for the CEBAF accelerator requires that two frequencies, 70.000 and 499.000 MHz, be distributed throughout the accelerator site. Proper operation of the multipass beam requires an energy spread of less than 2.5 {times} 10{sup {minus}5}. This imposes stringent constraints on the allowed slow phase error, in turn implying that there must be active regulation of the phase of the distributed reference frequencies. There are several methods already in use that regulate the phase of a distributed signal. A SLAC type pulsed microwave interferometer was not readily applicable, as this method uses the off time in a pulsed accelerator to perform its phase correction and measurement; CEBAF is a continuous device with every RF bucket filled. Since the CEBAF system requires amplifiers in the distribution line, a diplexed reference signal such as that used at LANL would require a series of discrete control loops, tied together with an overall control loop. It was felt that a less compl

Krycuk, Anton; Mahoney, Kelly; Simrock, Stefan

1991-05-01

101

Distribution system reconfiguration for optimal operation of distributed generation  

Microsoft Academic Search

Using Distributed Generation (DG) is an interesting topic that has drawn attention of electrical engineers in recent years. The presence of these generation units in distribution systems, although has many advantages and benefits, has to be applied after performing detailed studies and investigations due to their complexities in operation, control and protection of network. Conventional electric distribution systems are radial

R. Tamizkar; S. A. M. Javadian; M.-R. Haghifam

2009-01-01

102

Distribution System Efficiency Improvement Guidebook.  

SciTech Connect

This report presents a simplified procedure for looking at a portion of a distribution system to determine the cost-effectiveness of making an investment to reduce losses. The exact calculation of losses is best done on a computer; however, many approximations have been made to simplify the calculations. The report is divided into sections dealing with conductors, transformers, modifications, reconductor, add phases, reinsulate, capacitors, economics, and examples.

United States. Bonneville Power Administration; CH2M Hill, Inc.

1981-12-01

103

Inclination Distribution of Exoplanetary Systems  

NASA Astrophysics Data System (ADS)

The Kepler Space Telescope is revealing for the first time valuable constraints on the inclination distribution of planetary systems with the discovery of systems of candidate multiple transiting planets. As an ensemble, the 170 candidate multi-transiting systems discovered by Kepler reveal a large population of 3-4 small nearly-coplanar planets with periods less than 125 days (Lissauer, Ragozzine, et al. 2011). The presence of multiple transiting planets does not measure the true mutual inclinations, but transit timing and duration variations (or lack thereof), multi-Rossiter-McLaughlin, and/or exoplanet mutual events can measure or put good constraints on true mutual inclinations in individual systems (Ragozzine & Holman 2010). I will discuss the recent results from Kepler observations on the inclination distributions of different exoplanet population. I will also discuss a new method for validating candidates in multi-transiting systems that uses the coplanarity of planetary systems to minimize the probability that such candidates are false positives. A summary of our understanding of exoplanetary inclinations and implications for the formation and evolution of planetary systems will also be provided. ESSII SOC: It is possible that I will focus my talk on a detailed analysis of KOI-500, the Kepler system with 5 candidate planets with new results showing that all the candidates are planets and discussing the intricate three-body resonance structure seen in this system. This work is supported by the Institute for Theory and Computation at Harvard University. Kepler was competitively selected as the tenth Discovery mission. Funding for this mission is provided by NASA's Science Mission Directorate.

Ragozzine, Darin; K. Team

2011-09-01

104

Two issues in the municipal ownership of electric power distribution systems. [Statistical\\/econometric scrutiny  

Microsoft Academic Search

Though municipal ownership of electric power distribution systems has been a growing public issue since the late 1960s, serious empirical econometric investigation of distribution has barely begun. The author opens with a critique of two recent works on distribution costs: one on distribution return to scale and one on comparative public\\/private efficiency. A new conceptualization of the factors influencing distribution

Neuberg

2009-01-01

105

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

106

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.

107

Distributed Generator Placement And Sizing in Unbalanced Radial Distribution System  

Microsoft Academic Search

To minimize power losses, it is important to determine the location and size of local generators to be placed in unbalanced power distribution systems. Because of some inherent features of unbalanced distribution systems, such as radial structure, large number of nodes, and a wide range of X\\/R ratios, the conventional techniques developed for the transmission systems generally fail to determine

T. Ramana; V. Ganesh; S. Sivanagaraju

2010-01-01

108

Zipf's Law in the Popularity Distribution of Chess Openings  

NASA Astrophysics Data System (ADS)

We perform a quantitative analysis of extensive chess databases and show that the frequencies of opening moves are distributed according to a power law with an exponent that increases linearly with the game depth, whereas the pooled distribution of all opening weights follows Zipf’s law with universal exponent. We propose a simple stochastic process that is able to capture the observed playing statistics and show that the Zipf law arises from the self-similar nature of the game tree of chess. Thus, in the case of hierarchical fragmentation the scaling is truly universal and independent of a particular generating mechanism. Our findings are of relevance in general processes with composite decisions.

Blasius, Bernd; Tönjes, Ralf

2009-11-01

109

75 FR 56920 - Express Mail Open and Distribute and Priority Mail Open and Distribute  

Federal Register 2010, 2011, 2012, 2013

...Tag 157 with Tag 257 (DDU), Tag 267 (SCF, NDC), and Label 257S (DDU), to assist...Ship Product File Download''). 2. For SCF distribution, use the destination in L005...Distribute containers destined to a NDC or SCF facility. b. Attach Tag 257 to sacks...

2010-09-17

110

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

Federal Register 2010, 2011, 2012, 2013

...Tag 157 with Tag 257 (DDU), Tag 267 (SCF, NDC), and Label 257S (DDU) for all...Ship Product File Download''). 2. For SCF distribution, use the destination in L005...Distribute containers destined to a NDC or SCF facility. b. Attach Tag 257 to sacks...

2010-11-26

111

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

112

Optimal reconfiguration of radial distribution systems to maximize loadability  

Microsoft Academic Search

This paper presents a new method for optimal reconfiguration of radial distribution systems (RDS). Optimal reconfiguration involves selection of the best set of branches to be opened, one each from each loop, such that the resulting RDS has the desired performance. Amongst the several performance criteria considered for optimal network reconfiguration, maximizing loadability is an important one. Owing to the

B. Venkatesh; Rakesh Ranjan; H. B. Gooi

2004-01-01

113

Agent-based distributed measurement system for advanced manufacturing  

Microsoft Academic Search

Intelligent software agent technology has been widely used in manufacturing to make plants more agile and dynamic to satisfy frequently changed requirements from market. After illustrating agent applications in measurement and manufacturing, a multi-agent architecture for measurement system for advanced manufacturing with characteristics of distribution, collaboration and openness is presented, which enables not only to perform measurement dynamically and autonomously

Guoqiang Lv; Qibin Feng; Haicheng Hu; Ping Jiang; Dan Ke

2005-01-01

114

A Calculus for Security Bootstrapping in Distributed Systems  

Microsoft Academic Search

A calculus of channel security properties is presented which allows the analysis and comparison of protocols for establishing secure channels in a distributed open system at a high level of abstraction. A channel is characterized by its direction, its time of availability and its security properties. Cryptographic primitives as well as trust relations are interpreted as transformations for channel security

Ueli M. Maurer; Pierre E. Schmid

1996-01-01

115

Open standard development platforms for distributed sensor networks  

Microsoft Academic Search

In the development of distributed security sensor networks a large variety of prototype systems have been implemented and tested. However these systems tend to be developer specific and require substantial overhead in demonstrating more than one application. To bridge the gap between embedded, networked systems and desktop simulation environments, systems are necessary which are easily deployable and allow extended operation

William Merrill; Katayoun Sohrabi; Lewis Girod; Jeremy Elson; Fredric Newberg; William J. Kaiser

2002-01-01

116

R-OSGi-based architecture of distributed smart home system  

Microsoft Academic Search

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

Jiankun Wu; Linpeng Huang; Dejun Wang; Fei Shen

2008-01-01

117

Defining A Distribution System for Computer-Controlled Distribution Automation  

Microsoft Academic Search

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

L. V. Mccall; B. J. Chambers

1983-01-01

118

Voltage control availability of distributed generators in power distribution system  

Microsoft Academic Search

In spite of many profitable or advantageous natures of distributed generators (DGs), for power systems, such badly behaved natures of DGs as (1) unstable power output, (2) voltage problem, (3)harmonics, (4)reverse power flow, etc. also exist. Therefore, it has been always emphasized that the unfavorable effects should not exist when distributed generators are connected to the power system. However, in

K. Nara; S. Ishizu; Y. Mishima

2005-01-01

119

Environment for Simulation of Distributed Systems.  

National Technical Information Service (NTIS)

The purpose of this research is to determine the feasibility of developing an environment for simulating the operations of distributed systems and mapping them into a parallel architecture. The distributed systems will consist of a hardware architecture a...

1990-01-01

120

Department of Defense Materiel Distribution System Study.  

National Technical Information Service (NTIS)

Transportation costs are one of the major factors in the review and analysis of the Defense Materiel Distribution System now under consideration by the DOD Materiel Distribution System (DODMDS) Study Group of the Joint Logistics Commanders. The purpose of...

J. C. Wolff R. S. Potter P. C. Alling R. W. LaPointe

1977-01-01

121

Passage Time Distribution for a Class of Queueing Networks: Closed, Open, or Mixed, with Different Classes of Customers with Applications to Computer System Modeling.  

National Technical Information Service (NTIS)

Networks of queues are important models of multiprogrammed time-shared computer systems and computer communication networks. Although equilibrium state probabilities of a broad class of network models have been derived in the past, analytic or approximate...

P. S. Yu

1977-01-01

122

Mace: language support for building distributed systems  

Microsoft Academic Search

Building distributed systems is particularly difficult bec ause of the asyn- chronous, heterogeneous, and failure-prone environment where these sys- tems must run. Tools for building distributed systems must strike a compro- mise between reducing programmer effort and increasing system efficiency. We present Mace , a C++ language extension and source-to-source compiler that translates a concise but expressive distributed syste m

Charles Edwin Killian; James W. Anderson; Ryan Braud; Ranjit Jhala; Amin Vahdat

2007-01-01

123

Dynamical Decoupling of Open Quantum Systems  

SciTech Connect

We propose a novel dynamical method for beating decoherence and dissipation in open quantum systems. We demonstrate the possibility of filtering out the effects of unwanted (not necessarily known) system-environment interactions and show that the noise-suppression procedure can be combined with the capability of retaining control over the effective dynamical evolution of the open quantum system. Implications for quantum information processing are discussed. {copyright} {ital 1999} {ital The American Physical Society}

Viola, L.; Lloyd, S. [d`Arbeloff Laboratory for Information Systems and Technology, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Knill, E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1999-03-01

124

Developing an Open System for the Assessment of Technology in Education: The Data Gathering Agent.  

ERIC Educational Resources Information Center

|Outlines design of an open computer system that relies on distributed computing for collection and storage of data from very large samples. Purpose of the system is to provide a base of reliable data for assessing impact of technology on delivery of educational materials. The system consists of an open instrument that generates student forms, an…

Oliva, Maurizio

1999-01-01

125

Distributed control system approach for a unified power system  

Microsoft Academic Search

This paper presents an approach for applying distributed control system, DCS for a unified power system. It is well known that the distributed control system is usually serves to control, largescale systems, such as unified power systems, production lines in factories, airplanes, and airport earth services. The proposed distributed control system consists of hardware software and a number of controllers

M. Z. El-Sadek; A. M. Hemeida; M. A. Abelwahab; A. Alkosy; S. A. Younies

2004-01-01

126

Stabilized fiber-optic frequency distribution system  

Microsoft Academic Search

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

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

1989-01-01

127

Integration of distributed generators into a real powerless distribution system  

Microsoft Academic Search

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

Samir Avdakovic; A. Lukac

2009-01-01

128

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

129

Simulation of urban water distribution system for distributed power generation  

Microsoft Academic Search

Distributed power generation is an emerging technique for satisfying the growing power demand due to the continuous population growth in the urban areas. Successful siting of distributed power generator needs to consider the spatial demand for power and the supporting infrastructures. One of the important supporting infrastructures is water supply system. This paper describes a framework that integrates urban growth

Preethi Prakash Rao; Ke Li

2011-01-01

130

Review on islanding operation of distribution system with distributed generation  

Microsoft Academic Search

The growing environmental concern and various benefits of distributed generation (DG) have resulted in significant penetration of DG in many distribution systems worldwide. One of the major expected benefits of DG is the improvement in the reliability of power supply by supplying load during power outage by operating in an island mode. However, there are many challenges to overcome before

Pukar Mahat; Zhe Chen; Birgitte Bak-Jensen

2011-01-01

131

Television Distribution System for Primary Schools.  

National Technical Information Service (NTIS)

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 t...

1977-01-01

132

UV disinfection in a model distribution system  

Microsoft Academic Search

Two model distribution systems were operated in parallel to investigate the impact of UV disinfection on water distribution system biofilms and microbial community composition. One system received an influent irradiated with UV light, whereas the control received the same influent with no treatment. The biofilm in the UV system, as compared to the control, was more responsive (i.e., had a

Nicki Pozos; Kate Scow; Stefan Wuertz; Jeannie Darby

2004-01-01

133

Models for Deploying Open Source and Commercial Software to Support Earth Science Data Processing and Distribution  

NASA Astrophysics Data System (ADS)

Software deployment is needed to process and distribute scientific data throughout the data lifecycle. Developing software in-house can take software development teams away from other software development projects and can require efforts to maintain the software over time. Adopting and reusing software and system modules that have been previously developed by others can reduce in-house software development and maintenance costs and can contribute to the quality of the system being developed. A variety of models are available for reusing and deploying software and systems that have been developed by others. These deployment models include open source software, vendor-supported open source software, commercial software, and combinations of these approaches. Deployment in Earth science data processing and distribution has demonstrated the advantages and drawbacks of each model. Deploying open source software offers advantages for developing and maintaining scientific data processing systems and applications. By joining an open source community that is developing a particular system module or application, a scientific data processing team can contribute to aspects of the software development without having to commit to developing the software alone. Communities of interested developers can share the work while focusing on activities that utilize in-house expertise and addresses internal requirements. Maintenance is also shared by members of the community. Deploying vendor-supported open source software offers similar advantages to open source software. However, by procuring the services of a vendor, the in-house team can rely on the vendor to provide, install, and maintain the software over time. Vendor-supported open source software may be ideal for teams that recognize the value of an open source software component or application and would like to contribute to the effort, but do not have the time or expertise to contribute extensively. Vendor-supported software may also have the additional benefits of guaranteed up-time, bug fixes, and vendor-added enhancements. Deploying commercial software can be advantageous for obtaining system or software components offered by a vendor that meet in-house requirements. The vendor can be contracted to provide installation, support and maintenance services as needed. Combining these options offers a menu of choices, enabling selection of system components or software modules that meet the evolving requirements encountered throughout the scientific data lifecycle.

Yetman, G.; Downs, R. R.

2011-12-01

134

THE SPATIAL DISTRIBUTION OF STARS IN OPEN CLUSTERS  

SciTech Connect

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

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

2009-05-10

135

Dependency of Belief in Distributed Systems.  

National Technical Information Service (NTIS)

The paper investigates the problem of dependency of belief in distributed environments, where an agent may take others' beliefs as its own beliefs. Kripke models for dependency of belief in distributed systems are presented. The notion of dependency of be...

Z. Huang

1989-01-01

136

Geometric phases in open tripod systems  

SciTech Connect

We first consider stimulated Raman adiabatic passages in a closed four-level tripod system. In this case, the adiabatic eigenstates of the system acquire real geometric phases. When the system is open and subject to decoherence they acquire complex geometric phases that we determine by a Monte Carlo wave function approach. We calculate the geometric phases and the state evolution in the closed as well as in the open system cases and describe the deviation between these in terms of the phases acquired. When the system is closed, the adiabatic evolution implements a Hadamard gate. The open system implements an imperfect gate and hence has a fidelity below unity. We express this fidelity in terms of the acquired geometric phases.

Moeller, Ditte; Madsen, Lars Bojer; Moelmer, Klaus [Lundbeck Foundation Theoretical Center for Quantum System Research, Department of Physics and Astronomy, University of Aarhus, DK-8000 (Denmark)

2008-02-15

137

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

2002-03-21

138

Distributed distribution energy management system (DDEMS) exploratory experiments  

Microsoft Academic Search

An example of an in-house solution to a distribution automation system is presented. The results of several experiments carried out to identify the types of tools needed to implement a commercial-grade system with in-house staff are reported. A description is given of the information management system, the division district power management system, the workstation and personal computer tools, and the

G. B. Sheble

1991-01-01

139

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

140

Heterogeneous distributed database systems for production use  

Microsoft Academic Search

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

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

1990-01-01

141

Reengineering legacy systems for distributed environments  

Microsoft Academic Search

In the last decade, we have seen an increasing use of both the object-oriented paradigm and distributed systems. As a result, there is increasing interest in migrating and reengineering legacy systems to these new hardware technologies and software development paradigms. We define a reengineering environment that assists with the migration of legacy systems to distributed object environments. The reengineering environment

Miguel A. Serrano; Doris L. Carver; Carlos Montes De Oca

2002-01-01

142

Modeling and analysis of DC distribution systems  

Microsoft Academic Search

Research on modification and replacement of conventional AC distribution system to DC is widely undergoing. When DC distribution is applied in a system with DC-preferred appliances, it is possible to enhance energy consumption efficiency by reducing conversion losses. Moreover, renewable energy sources and storage devices can be fully utilized because they are more compatible with DC based system where generated

Gab-Su Seo; Jongbok Baek; Kyusik Choi; Hyunsu Bae; Bohyung Cho

2011-01-01

143

Quantum dynamics and open quantum systems  

NASA Astrophysics Data System (ADS)

The thesis deals with the quantum mechanical description of dynamical properties of open systems, and, in particular, with studying the temporal evolution of quantum systems interacting with their environments. In this thesis we apply a microscopic approach to study such systems thus explicitly considering the hamiltonian of the environment and its interaction with the quantum system under consideration. We also consider how the microscopic hamiltonians can be used in order to produce several logical operations as a result of the temporal dynamics of the systems governed by such hamiltonians. In the introductory chapter we start by discussing the physical motivation for studying open quantum systems and describe the most significant phenomena that result due to such interactions. We also briefly outline the experimental realizations in which the type of systems studied in the dissertation can arise. Then, in chapter 1, we consider a model of a quantum spin interacting with free electron gas. It is shown that this model can be mapped onto the spin-boson model with an Ohmic spectral function. The criterion for the localization of the spin is explicitly derived in terms of the parameters of the original fermionic model. In chapter 2, we study a general quantum system interacting with an environment modeled by the bosonic heat bath of the Caldeira and Leggett type. We argue that this model provides an appropriate description of adiabatic quantum decoherence, i.e. loss of entanglement on time scales short compared to those of thermal relaxation processes associated with energy exchange with the bath. Calculation of the elements of the reduced density matrix of the system is carried out exactly, and time-dependent decoherence is identified, similar to recent results for related models. Our key finding is that the decoherence process is controlled by the spectral properties of the interaction rather than by the system's hamiltonian. In chapter 3, a model of a quantum spin interacting with a spin environment is considered. The interaction is chosen to be such that the state of the environment is conserved. The reduced density matrix of the spin is calculated exactly for arbitrary coupling strength. The density matrix reaches its stationary state at t = /infty, which can be explicitly expressed in terms of elementary functions. It turns out that this state is quite different from the canonical distribution thus pointing out that the Markovian assumption is playing an essential role quantum mechanical description of a heat bath. Chapter 4 deals with quantum computing. We propose to design multi-spin quantum gates in which the input and output two-state systems (spins) are not necessarily identical. We outline the design criteria for such devices and then review recent results for single-unit Hamiltonians that accomplish the NOT and XOR functions. Chapter 5 is devoted to the problem of quantum copying. We consider a quantum evolution in which the basis states of I at time t are duplicated in at least two of the systems I, C, D, at time t + /Delta t. In essence, the restriction on the initial target states is exchanged for uncertainty as to which two of the three qubits retain copies of the initial source state. Finally, in chapter 6, we summarize and discuss the results obtained in the thesis and also describe directions for future research.

Mozyrsky, Dima

1999-02-01

144

How skew distributions emerge in evolving systems  

NASA Astrophysics Data System (ADS)

Despite the ubiquitous emergence of skew distributions such as power law, log-normal, and Weibull distributions, there still lacks proper understanding of the mechanism as well as relations between them. It is studied how such distributions emerge in general evolving systems and what makes the difference between them. Beginning with a master equation for general evolving systems, we obtain the time evolution equation for the size distribution function. Obtained in the case of size changes proportional to the current size are the power law stationary distribution with an arbitrary exponent and the evolving distribution, which is of either log-normal or Weibull type asymptotically, depending on production and growth in the system. This master equation approach thus gives a unified description of those three types of skew distribution observed in a variety of systems, providing physical derivation of them and disclosing how they are related.

Choi, M. Y.; Choi, H.; Fortin, J.-Y.; Choi, J.

2009-02-01

145

BK950037 Component & Distribution Info System  

Center for Biologics Evaluation and Research (CBER)

Text Version... 75MMH PRODUCT TRADE NAME: Components and Distribution Information System COMMON NAME: CDIS PREDICATE ... More results from www.fda.gov/downloads/biologicsbloodvaccines/bloodbloodproducts

146

Quantum Simulation for Open-System Dynamics  

NASA Astrophysics Data System (ADS)

Simulations are essential for predicting and explaining properties of physical and mathematical systems yet so far have been restricted to classical and closed quantum systems [1,2]. Although forays have been made into open-system quantum simulation [3], the strict algorithmic aspect has not been explored yet is necessary to account fully for resource consumption to deliver bounded-error answers to computational questions. An open-system quantum simulator would encompass classical and closed-system simulation and also solve outstanding problems concerning, e.g. dynamical phase transitions in non-equilibrium systems, establishing long-range order via dissipation, verifying the simulatability of open-system dynamics on a quantum Turing machine. We construct an efficient autonomous algorithm for designing an efficient quantum circuit to simulate many-body open-system dynamics described by a local Hamiltonian plus decoherence due to separate baths for each particle. The execution time and number of gates for the quantum simulator both scale polynomially with the system size.[4pt] [1] S. Lloyd, Science 273, 1073 (1996).[0pt] [2] D. W. Berry et al, Comm. Math. Phys. 270, 359 (2007).[0pt] [3] M. Kliesch et al, Phys. Rev. Lett. 107, 120501 (2011).

Wang, Dong-Sheng; de Oliveira, Marcos Cesar; Berry, Dominic; Sanders, Barry

2013-03-01

147

Quantum arrival time for open systems  

SciTech Connect

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

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

2010-07-15

148

Harmonic management in mv distribution systems  

Microsoft Academic Search

With many distribution customer loads being sensitive to excessive harmonic voltage distortion, electricity distribution network service providers should now be looking towards preventative measures to ensure that voltage distortion levels remain within limits set by the appropriate standards. Measures will need to be taken at the planning stage to ensure distribution systems are able to meet harmonic limits recommended by

Duane Robinson

2003-01-01

149

Multicanonical distribution: statistical equilibrium of multiscale systems.  

PubMed

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

Salazar, Domingos S P; Vasconcelos, Giovani L

2012-11-14

150

Multicanonical distribution: Statistical equilibrium of multiscale systems  

NASA Astrophysics Data System (ADS)

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

Salazar, Domingos S. P.; Vasconcelos, Giovani L.

2012-11-01

151

Formal test specifications in open systems  

Microsoft Academic Search

The development of formal test specifications for an open system standard is described. The effort is being conducted within the environment provided by the Clemson Automated Testing System (CATS). CATS features the ability to automatically translate formal test specifications into executable tests. The formal test specifications are written in accordance with a specification language designed in support of this effort.

J. F. Leathrum; K. A. Liburdy

1995-01-01

152

Test data visualization for open system standards  

Microsoft Academic Search

This paper describes a data visualization tool developed to support prototype development and testing of software standard interfaces in the open systems environment. The visualization capability is an extension of the Clemson Automated Testing System (CATS). CATS is a research facility which has proven valuable in exposing and addressing critical issues in emerging areas such as the IEEE POSIX real-time

D. Crane; J. F. Leathrum; Kathleen A. Liburdy

1994-01-01

153

Thermodynamics: Energy of closed and open systems  

Microsoft Academic Search

Summary  The definition of energy, in thermodynamics, is deepened by stating operative definitions of the basic concepts of physics\\u000a on which it rests, such as those of isolated system, ambient of a system, separable system and set of separable states. Then\\u000a the definition of energy is rigorously extended to open systems. The extension gives a clear physical meaning to the concept

E. Zanchini

1988-01-01

154

Distributed System Development in B  

Microsoft Academic Search

The B-Method is a method for the stepwise derivation of sequential programs.In this paper we show how the B-Method can be used for designingdistributed systems by embedding action systems within this method. Theaction system formalism is designed for the construction of parallel anddistributed systems in a stepwise manner within the refinement calculus.We describe how action systems are written in B

M. Butler; M. Walden

1996-01-01

155

Dependable distributed embedded system assessment platform design  

Microsoft Academic Search

Dependable distributed embedded systems (DDES) are being deployed widely in automobile industry over the world. These systems always post rigorous requirement for timing accuracy and reliability. Both hardware and software architecture have important effect on the system dependability. Adding or substitute for more reliable hardware could increase the system reliability moreover achieves faster system response. Apparently this would increase the

Huang Qiang; Liang XiaoFeng; Zhu YingYing

2007-01-01

156

Knowledge and Inhibition in Asynchronous Distributed Systems.  

National Technical Information Service (NTIS)

In an asynchronous distributed system, processes communicate only via message passing along channels with unbounded transmission time. Relative process speeds are arbitrary and processes do not have access to a common clock. For such systems, a useful mea...

K. E. Taylor

1990-01-01

157

The Center for Networking and Distributed Systems  

NSDL National Science Digital Library

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

158

Impact of high penetration residential PV systems on distribution systems  

Microsoft Academic Search

This paper investigates the operation and protection issues on a distribution system with high penetration of residential PV systems. PV systems are smaller scale resources and therefore they have different impact on a distribution circuit than larger scale resources. The paper indeed considers a typical residential feeder and investigates PV system impacts on the system at different penetration levels. Simulations

M. E. Baran; H. Hooshyar; Z. Shen; J. Gajda; K. M. M. Huq

2011-01-01

159

Determining the impact of distributed generation on power systems. I. Radial distribution systems  

Microsoft Academic Search

Distributed generation (DG) has much potential to improve distribution system performance and it should be encouraged. However, distribution system designs and operating practices are normally based on radial power flows and this creates a special challenge to the successful introduction of distributed generation. This paper has described a few of the issues that must be considered to insure that DG

Philip P. Barker; Robert W. de Mello

2000-01-01

160

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

161

NGSCB: A Trusted Open System  

Microsoft Academic Search

We describe Microsoft's Next Generation Secure Computing Base (NGSCB). The system provides high assurance computing in a manner consistent with the commercial requirements of mass market systems. This poses a number of challenges and we describe the system architecture we have used to overcome them. We pay particular attention to reducing the trusted computing base to a small and manageable

Marcus Peinado; Yuqun Chen; Paul England; John Manferdelli

2004-01-01

162

Facility location models for distribution system design  

Microsoft Academic Search

The design of the distribution system is a strategic issue for almost every company. The problem of locating facilities and allocating customers covers the core topics of distribution system design. Model formulations and solution algorithms which address the issue vary widely in terms of fundamental assumptions, mathematical complexity and computational performance. This paper reviews some of the contributions to the

Andreas Klose; Andreas Drexl

2005-01-01

163

Asset management, risk, and distribution system planning  

Microsoft Academic Search

Asset management is the art of balancing cost, performance, and risk. Viewed in this way, it has profound implications on distribution system planning, since traditional approaches balance only cost and performance without regard to risk. This paper examines distribution system planning in the context of reliability, risk, and asset management. It begins by providing an overview of asset management and

Richard E. Brown; John H. Spare

2004-01-01

164

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

165

RF phase distribution systems at the SLC  

SciTech Connect

Modern large linear accelerators require RF distribution systems with minimal phase drifts and errors. Through the use of existing RF coaxial waveguides, and additional installation of phase reference cables and monitoring equipment, stable RF distribution for the SLC has been achieved. This paper discusses the design and performance of SLAC systems, and some design considerations for future colliders. 6 refs., 4 figs.

Jobe, R.K.; Schwarz, H.D.

1989-04-01

166

A scalable distributed information management system  

Microsoft Academic Search

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

Praveen Yalagandula; Michael Dahlin

2004-01-01

167

Distributed control enables flexible intelligent system development  

Microsoft Academic Search

Intelligent systems that central physical tasks all need to turn intent into action. The end result is the generation of controlled motion, whether it's for an industrial process, the movement of a machine or vehicle, or movement of a mechanism for a specific function. In this context, RedZone Robotics has developed the Distributed Control System, a low-level distributed controller. Originally

J. N. Callen

1998-01-01

168

Distribution system: cost of repair and replacement  

Microsoft Academic Search

The Safe Drinking Water Act of 1974 mandates that EPA be concerned with the supply of potable water to the consumer. Although most emphasis has been placed on water quality as it leaves the treatment plant, interest is increasing in the role of the distribution system in causing water-quality deterioration. In addition, distribution systems often account for 80% of total

R. M. Clark; R. G. Eilers; J. A. Goodrich

1987-01-01

169

Cooperative Validation in Distributed Control Systems Design  

Microsoft Academic Search

The team of engineers designing and implementing distributed control system software must communicate within a multidisciplinary environment. One of the main problems is the interaction between hardware and software solutions. Software project presumptions may not be based only on minimum hardware requirements and on technology rules. Modern distributed control systems embrace all aspects of a complex and widespread object. Hence,

Dariusz Choinski; Mieczyslaw Metzger; Witold Nocon; Grzegorz Polaków

2007-01-01

170

Adiabatic approximation for weakly open systems  

SciTech Connect

We generalize the adiabatic approximation to the case of open quantum systems, in the joint limit of slow change and weak open system disturbances. We show that the approximation is 'physically reasonable' as under wide conditions it leads to a completely positive evolution, if the original master equation can be written on a time-dependent Lindblad form. We demonstrate the approximation for a non-Abelian holonomic implementation of the Hadamard gate, disturbed by a decoherence process. We compare the resulting approximate evolution with numerical simulations of the exact equation.

Thunstroem, Patrik; Aaberg, Johan; Sjoeqvist, Erik [Department of Quantum Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala (Sweden)

2005-08-15

171

Declarative Mediation in Distributed Systems  

Microsoft Academic Search

The mediation architecture is widely used for bridging heterogeneous data sources. We investigate how such architecture can\\u000a be extended to embrace information processing services and suggest a framework that supports declarative specification of\\u000a mediation logic. In this paper we show how our framework can be applied to enrich interface descriptions of distributed objects\\u000a and to integrate them with other client\\/server

Sergey Melnik

2000-01-01

172

An Architecture for Open Learning Management Systems  

Microsoft Academic Search

There exists an urgent demand on defining architectures for Learning Management Systems, so that high-level frameworks for understanding these systems can be discovered, and quality attributes like portability, interoperability, reusability and modifiability can be achieved. In this paper we propose a prototype architecture aimed to engineer Open Learning Management Systems, that professes state-of-the-art software engineering techniques such as layered structure

Simos Retalis; Manolis Skordalakis

2003-01-01

173

An Architecture for Open Learning Management Systems  

Microsoft Academic Search

There exists an urgent demand on defining architectures for Learning Management Systems, so that high-level frameworks for\\u000a understanding these systems can be discovered, and quality attributes like portability, interoperability, reusability and\\u000a modifiability can be achieved. In this paper we propose a prototype architecture aimed to engineer Open Learning Management\\u000a Systems, that professes state-of-the-art software engineering techniques such as layered structure

Symeon Retalis; Manolis Skordalakis

2001-01-01

174

Distributed algorithms over communicating membrane systems.  

PubMed

This paper presents fundamental distributed algorithms over membrane systems with antiport carriers. We describe distributed algorithms for collecting and dispersing information, leader election in these systems, and the mutual exclusion problem. Finally, we consider membrane systems producing correct results despite some failures at some of the components or the communication links. We show that membrane systems with antiport carriers provide an appropriate model for distributed computing, particularly for message-passing algorithms interpreted here as membrane transport in both directions, namely when two chemicals behave as input and output messages and pass the membranes in both directions using antiport carriers. PMID:12915270

Ciobanu, Gabriel

2003-07-01

175

A New Reconfiguration Approach for Distribution System with Distributed Generation  

Microsoft Academic Search

This paper presents a very simple and efficient method for minimum loss reconfiguration of distribution system based on sensitivity and branch-exchange algorithm. This paper uses the real power loss sensitivity with respect to the admittance of candidate branches to decide the real power incremental loss in the first stage which decides which loop switch should be closed. A branch exchange

Li Qiwang; Ding Wei; Zhang Jianquan; Liu Anhui

2009-01-01

176

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

2002-09-26

177

Distributed computer systems: Four case studies  

Microsoft Academic Search

Distributed computer applications built from off-the-shelf hardware and software are increasingly common. This paper examines four such distributed systems with contrasting degrees of decentralized hardware, control, and redundancy. The first is a one-site system, the second is a node replicated at a remote site for disaster backup, the third is a multi-site system with central control, and the fourth is

Jim Gray; Mark Anderton

1987-01-01

178

Communication mode of distributed multisensor detection system  

Microsoft Academic Search

Distributed Multi-sensor Detection System is a wide field distributed wireless detection system, which is composed of Command Center and varieties of Detection Units. The Command Center acquires a lot of real-time information from the area that has been monitored by means of bi-directional communication between it and each unit. Communication mode that has been adopted in this detection system will

Min Hua; Yingjun Meng; Dongsheng Gu; Ying Liu

2002-01-01

179

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

180

Reliability improvement of distribution systems using SSVR.  

PubMed

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

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

2008-11-11

181

Implementation of genetic algorithm for distribution systems loss minimum re-configuration  

Microsoft Academic Search

The loss minimum reconfiguration problem in the open loop radial distribution system is basically one of complex combinatorial optimization, since the normal open sectionalizing switches must be determined appropriately. The genetic algorithm was successfully applied to the loss minimum reconfiguration problem. In the proposed algorithm, strings consist of sectionalizing switch status or radial configurations, and the fitness function consists of

Koichi Nara; Atsushi Shiose; Minoru Kitagawa; Toshihisa Ishihara

1992-01-01

182

The Open Systems University and Organizational Intelligence.  

ERIC Educational Resources Information Center

The open systems model of the university defines the function of institutional research to be a cybernetic one. The internal and external reality-testing function is a vital duty and a moral charge. Though policy makers and educational practitioners can carry on for a considerable length of time with organizational intelligence of low validity,…

Counelis, James Steve

183

Integrating photovoltaics into utility distribution systems  

SciTech Connect

Electric utility distribution system impacts associated with the integration of distributed photovoltaic (PV) energy sources vary from site to site and utility to utility. The objective of this paper is to examine several utility- and site-specific conditions which may affect economic viability of distributed PV applications to utility systems. Assessment methodology compatible with technical and economic assessment techniques employed by utility engineers and planners is employed to determine PV benefits for seven different utility systems. The seven case studies are performed using utility system characteristics and assumptions obtained from appropriate utility personnel. The resulting site-specific distributed PV benefits increase nonsite-specific generation system benefits available to central station PV plants as much as 46%, for one utility located in the Southwest.

Zaininger, H.W. [Zaininger Engineering Co., Inc., San Jose, CA (United States); Barnes, P.R. [Oak Ridge National Lab., TN (United States)

1995-03-01

184

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

185

Open system for micro-ultrasound.  

PubMed

Micro-ultrasound is able to delineate small structures with fine spatial resolution on the order of several tens of microns. It is an invaluable imaging tool for many clinical and preclinical applications. This paper presents the development of an open system for various biomedical studies. The system design was based on field programmable gate array (FPGA) embedded in a printed circuit board to achieve flexible imaging applications. The major image processing algorithms were achieved by the novel field programmable technology for high speed and flexibility. Real-time imaging processing was achieved by fast processing algorithms and high speed data transfer interface. Extensive tests including hardware, algorithms, tissue mimicking phantom, and tissue specimen measurements were conducted to demonstrate good performance of the system. Multi-modality imaging was also facilitated by the developed open system. PMID:24109633

Qiu, Weibao; Zheng, Hairong; Sun, Lei

2013-07-01

186

Controlling open quantum systems using fast transitions  

NASA Astrophysics Data System (ADS)

Unitary control and decoherence appear to be irreconcilable in quantum mechanics. When a quantum system interacts with an environment, control strategies usually fail due to decoherence. In this article we implement a time-optimal unitary control protocol suitable for quantum open systems. The method is based on successive diabatic and sudden switch transitions in the avoided crossings of the energy spectra of closed systems. We show that the speed of this control protocol meets the fundamental bounds imposed by the quantum speed limit, thus making this scheme ideal for application where decoherence needs to be avoided. We show that this method can achieve complex control strategies with high accuracy in quantum open systems.

Poggi, Pablo M.; Lombardo, Fernando C.; Wisniacki, Diego A.

2013-02-01

187

Intelligent Distributed Intrusion Detection Systems of Computer Communication Systems  

Microsoft Academic Search

The paper is devoted to present various intelligent, distributed network-based intrusion detection systems architectures and quality measures. Moreover an impact of network and their intrusion detection system architectures parameters on the intrusion detection systems quality is discussed.

Adam Grzech

2009-01-01

188

Design and Implementation of Ceph: A Scalable Distributed File System  

SciTech Connect

File system designers continue to look to new architectures to improve scalability. Object-based storage diverges from server-based (e.g. NFS) and SAN-based storage systems by coupling processors and memory with disk drives, delegating low-level allocation to object storage devices (OSDs) and decoupling I/O (read/write) from metadata (file open/close) operations. Even recent object-based systems inherit decades-old architectural choices going back to early UNIX file systems, however, limiting their ability to effectively scale to hundreds of petabytes. We present Ceph, a distributed file system that provides excellent performance and reliability with unprecedented scalability. Ceph maximizes the separation between data and metadata management by replacing allocation tables with a pseudo-random data distribution function (CRUSH) designed for heterogeneous and dynamic clusters of unreliable OSDs. We leverage OSD intelligence to distribute data replication, failure detection and recovery with semi-autonomous OSDs running a specialized local object storage file system (EBOFS). Finally, Ceph is built around a dynamic distributed metadata management cluster that provides extremely efficient metadata management that seamlessly adapts to a wide range of general purpose and scientific computing file system workloads. We present performance measurements under a variety of workloads that show superior I/O performance and scalable metadata management (more than a quarter million metadata ops/sec).

Weil, S A; Brandt, S A; Miller, E L; Long, D E; Maltzahn, C

2006-04-19

189

An Open Source Power System Analysis Toolbox  

Microsoft Academic Search

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

Federico Milano

2005-01-01

190

Web tool opens up power system visualization  

Microsoft Academic Search

This article presents a flexible architecture of a Web-based tool that serves as a platform for power system visualization with open data structures. Different from regular applications, this platform may be viewed as a semicompleted application. It implements common features of a power system application such as GIS-like drawing and visualization, built-in topology processor, and so on. Meanwhile, the platform

Fangxing Li

2003-01-01

191

Distributed Administrative Management Information System (DAMIS).  

ERIC Educational Resources Information Center

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

Juckiewicz, Robert; Kroculick, Joseph

192

Implementing Distributed Workflow Systems from XML Specifications  

Microsoft Academic Search

In enterprise-wide distributed workflow, multiple users co op- erate towards some common goal following predefined task specifications. This paper presents an approach for constru ct- ing a distributed workflow system starting from its XML spec- ification in terms of various participants' roles, access ri ghts based on roles, shared objects, operations, and workflow con - straints. The specifications are integrated

Anand R. Tripathi; Tanvir Ahmed; Vineet Kakani; Shremattie Jaman

2000-01-01

193

BIOFILM IN DRINKING WATER DISTRIBUTION SYSTEMS  

EPA Science Inventory

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

194

Implementing interactive configuration management for distributed systems  

Microsoft Academic Search

The paper describes an environment for interactive configuration management of software for distributed applications and services. Configuration management involves creating the components which form a distributed system; allocating these components to physical nodes and binding the interfaces of the components to each other or to existing services. Components and their required and provided interfaces are represented and accessible in the

Halldor FOSSA; Morris Sloman

1996-01-01

195

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

196

Distributed Reactive Systems Are Hard to Synthesize  

Microsoft Academic Search

The problem of synthesizing a finite-state distributed reactive system is considered. Given a distributed architecture A, which comprises several processors P1, . . ., P k and their interconnection scheme, and a propositional temporal specification ?, a solution to the synthesis problem consists of finite-state programs ?1, . . ., ?k (one for each processor), whose joint (synchronous) behavior maintains

Amir Pnueli; Roni Rosnert

1990-01-01

197

Distribution control at Exhaust Systems Europe  

Microsoft Academic Search

Discusses the selection of distribution control techniques for a manufacturer of exhaust systems. A method for this selection process is proposed and worked out for the case study company. Argues that selecting one control technique for a complete company is not advisable. Distribution control should be differentiated to clusters of products that have a similar set of product, process and

1996-01-01

198

System approach to distributed sensor management  

Microsoft Academic Search

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

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

2010-01-01

199

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...

200

Air Mobile Utility Distribution Systems.  

National Technical Information Service (NTIS)

Phase I involved: (1) a feasibility study of various plastic piping and insulation systems, (2) a state of the art survey to select candidate materials for testing and evaluation, (3) selection and development of a suitable testing program. Phase II consi...

M. A. White F. W. Spillers R. D. Duke

1975-01-01

201

Open architecture cardiology information system  

US Patent & Trademark Office Database

A clinical information reporting system for use with an electronic database for a health care facility, the electronic database being a rotational and modular database for the provision of a scalable and extensible configuration preferably consisting of a workstation as the base configuration and being configurable for use in small and medium network situations and being particularly adapted for the receipt, manipulation, modification and generation of cardiology reports such as resting ECG records and stress ECG records.

Wright; Gregory John (Seattle, WA); Hochberg; Philip Scott (Kirkland, WA); Bellusci; Darcy B. (Redmond, WA); Brinster; Eric Gregory (Everett, WA); Brinton; Mark Willard (Bellevue, WA); Folkerts; Sue R. (Snohomish, WA); Foster; Brian Timothy (Suquamish, WA); King; Anthony Edward (Seattle, WA); Maloney; Kevin Patrick (Seattle, WA); Newell; Todd Edwin (Kent, WA); Peterson; Eric David (Redmond, WA); Pierce; Thomas Dean (Edmonds, WA); Rabbers; David L. (Newcastle, WA); Shoemaker; Linda Jean (Edmonds, WA); Tolan; John Joseph (Snohomish, WA); Wootten; James M. (Kirkland, WA); Bolles; Gregory Allin (Snohomish, WA); Goddard; Kathie (Bellevue, WA); Malley; John Anthony (Seattle, WA); Schmidt; Kurt (Redmond, WA); Ly; Chou Ying (Kirkland, WA)

1999-12-21

202

Computer Systems for Distributed and Distance Learning.  

ERIC Educational Resources Information Center

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

Anderson, M.; Jackson, David

2000-01-01

203

A Survey of Distributed File Systems  

Microsoft Academic Search

Abstract This paper is a survey of the current state of the art in the design and implementation of distributed file systems. It consists of four major parts: an overview of background material, case studies of a number of contemporary file systems, identification of key design techniques, and an examination of current research issues. The systems surveyed are Sun NFS,

M. Satyanarayanan

1989-01-01

204

Communication synthesis for distributed embedded systems  

Microsoft Academic Search

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

Ross B. Ortega; Gaetano Borriello

1998-01-01

205

Ratings in Distributed Systems: A Bayesian Approach  

Microsoft Academic Search

For distributed systems at large and e-commerce systems in particular, ratings play an increasingly important role. Ratings confer reputation measures about sources. This paper reports our formalization of the rating process. This paper argues that ratings should be context- and individual- dependent quantities. In contrast to existing rating systems in many e-commerce or developer sites, our approach makes use of

Lik Mui; Mojdeh Mohtashemi; Cheewee Ang; Peter Szolovits; Ari Halberstadt

2001-01-01

206

Foundations of Knowledge for Distributed Systems.  

National Technical Information Service (NTIS)

Halpern and Moses present an interesting discussion of knowledge and common knowledge and common knowledge for distributed systems. They argue that while common knowledge is desirable, it is unattainable in certain settings. They suggest a hierarchy of we...

M. J. Fisher N. Immerman

1985-01-01

207

Adaptive Distribution System Protection: Final Report.  

National Technical Information Service (NTIS)

This report presents concepts, functions, and organizations of adaptive distribution system protection (ADSP) schemes. ADSP constantly monitors real time data, update relay characteristics and upper and lower bounds of control functions when required, and...

K. R. Shan

1987-01-01

208

Management of Water Distribution System Components.  

National Technical Information Service (NTIS)

The purpose of the study is to (1) analyze main break failures and (2) incorporate other drinking water distribution system components into a data base management structure for reliability analyses. Reliability analysis should be a part of an overall oper...

J. A. Goodrich C. P. S. Frebis E. J. Read R. M. Clark

1987-01-01

209

AC Distribution System for TFTR Pulsed Loads.  

National Technical Information Service (NTIS)

This paper outlines the AC distribution system associated with the Tokamak Fusion Test Reactor and discusses the significant areas related to design, protection, and equipment selection, particularly where there is a departure from normal utility and indu...

R. F. Carroll S. Ramakrishnan G. N. Lemmon W. I. Moo

1977-01-01

210

Distributed acoustic conversation shielding system  

US Patent & Trademark Office Database

A conversation shielding system comprises sensors that detect the location of a confidential conversation and the presence and location of a potential eavesdropper, audio output devices that produce masking sounds to shield the conversation from the eavesdropper, and a controller that automatically controls the operation of the output devices in response to data from the sensors. An optional portable controller may manually engage the system. A method for shielding conversation comprises identifying a conversation to be shielded, detecting a potential eavesdropper, automatically determining masking sound types, locations and volume that will shield the conversation, directing emission of masking sounds from at least one audio output device in order to shield the conversation, including adjusting the masking sound type, location, and volume in response to movement of the conversation or the eavesdropper, and continuing to shield the conversation until it ends or the eavesdropper is no longer detected.

Paradiso; Joseph A. (Medford, MA); Ono; Yasuhiro (Saitama, JP)

2012-07-24

211

Reconfiguration of Distributed Embedded-Control Systems  

Microsoft Academic Search

This paper deals with distributed multiagent reconfig- urable embedded-control systems following the component-based International Industrial Standard IEC61499 in which a function block (FB) is an event-triggered software component owning data and a control application is a distributed network of FBs. We de- fine an architecture of reconfigurable multiagent systems, where a reconfiguration agent modeled by nested state machines is affected

Mohamed Khalgui; Olfa Mosbahi; Zhiwu Li; Hans-Michael Hanisch

2011-01-01

212

A Generalized Model For Electric Distribution Systems  

Microsoft Academic Search

A generalized mathematical model is constructed of single-phase induction machines employed within a three-phase distribution system. It is shown that this composite model retains single-phase distribution detail and describes the intrinsic characteristics of the single-phase induction generator. Power system fault(s) and circuit breaker response(s) are also modeled. Preliminary results of digital simulation indicate that a small integration step size is

H. J. Robinson; T. W. Reddoch; J. W. Klein

1981-01-01

213

Distribution system modelling for voltage stability studies  

Microsoft Academic Search

This paper presents a method to include a radial distribution system, with cascaded tap-changers, in voltage stability studies. A rural distribution system, including the 50 kV, 20 kV, 10 kV and 0.4 kV levels, has been studied. A detailed model of the network down to the customer level, with all lines and transformers explicitly represented, has been compared with a

Rikard Lind; D. Karlsson

1996-01-01

214

Geometric magnetism in open quantum systems  

NASA Astrophysics Data System (ADS)

An isolated classical chaotic system, when driven by the slow change in several parameters, responds with two reaction forces: geometric friction and geometric magnetism. By using the theory of quantum fluctuation relations, we show that this holds true also for open quantum systems and provide explicit expressions for those forces in this case. This extends the concept of Berry curvature to the realm of open quantum systems. We illustrate our findings by calculating the geometric magnetism of a damped charged quantum harmonic oscillator transported along a path in physical space in the presence of a magnetic field and a thermal environment. We find that, in this case, the geometric magnetism is unaffected by the presence of the heat bath.

Campisi, Michele; Denisov, Sergey; Hänggi, Peter

2012-09-01

215

Examination and characterization of distribution system biofilms.  

PubMed Central

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

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

1987-01-01

216

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

217

Kinetic simulation of open beam-plasma systems  

SciTech Connect

Kinetic simulation of open plasma systems is considered within the Maxwell and Vlasov-Fokker-Planck equations (MVFP). Two approaches to the discrete simulation of open beam-plasma systems are described. 16 refs., 5 figs.

Batishchev, O.V.; Karas, V.I.; Levchenko, V.D. [Keldysh Institute of Applied Mathematics, Moscow (Russian Federation)] [and others

1994-07-01

218

REAL TIME SCHEDULING METHODS REQUIREMENTS IN DISTRIBUTED CONTROL SYSTEMS  

Microsoft Academic Search

Distributed control systems involve three main disciplines: control systems, real time systems, and communication systems. Control systems, due their stringent timing constraints, demand real time computing technology. Distributed control systems need communication systems when distributing sensors, actuators, the control procedures and data messaging. In general, demands of distributed control systems and properties of real time scheduling algorithms differ, for example,

Pau Martí; Ricard Villà; Josep M. Fuertes; Gerhard Fohler

2000-01-01

219

Utility interface problems of distributed PV system  

SciTech Connect

The authors theoretically examined the number of small scale (3-KW) PV systems which can be installed, considering voltage variation and harmonics, in a power distribution system and put in simultaneous grid-connected operation. Consequently, as long as adequate filters are installed, the total capacity of PV systems allowed to be connected with low voltage distribution feeders is about 15% of the capacity of main transformer of power distribution line for line-commutated systems, and about 40% for self-commutated ones. This paper also describes that protective coordination between small scale PV systems and utility grid can be accomplished by fuses and NFB at grid-connected points as a rule, and particular over/under-voltage relays or overcurrent relays or over/under-frequency relays may not be equipped externally but provided as control functions of inverters.

Takeda, Y.; Hashimoto, E.; Hayashi, T.; Takigawa, K.

1984-05-01

220

Optimal monitoring of water distribution systems  

NASA Astrophysics Data System (ADS)

The supervisory control and data acquisition (SCADA) technology is commonly used in water distribution systems in recently years. Monitoring is one of the most important steps in SCADA's implementation, and in reality monitoring stations used for water pressure are usually decided by experience or simply evenly distributed. For the purpose of more efficient monitoring, a method for optimal monitoring of water pressure in a water distribution system is proposed in this paper, in which, a sensitivity analysis is conducted for determining the sensitivity equation, and the sensitivity equation is then solved by a least-square method. It is found from examples that the method provides an efficient and practical way in which optimal monitoring scheme of water distribution system may be decided.

Liang, Jianwen; Xiao, Di; Zhang, Hongwei; Zhao, Xinhua

2003-08-01

221

Operational Survivability in Gracefully Degrading Distributed Processing Systems.  

National Technical Information Service (NTIS)

A simulator was designed and developed which will model possible distributed system network topologies, distributed system application topologies and their effect on application system performance as the configuration of the distributed system network is ...

E. W. Martin

1980-01-01

222

Cooperative Autonomic Management in Dynamic Distributed Systems  

NASA Astrophysics Data System (ADS)

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

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

223

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

224

Optimal monitoring of water distribution systems (II)  

NASA Astrophysics Data System (ADS)

The supervisory control and data acquisition (SCADA) technology has been used in water distribution systems in recently years, in which, waterhead at some nodes and/or flowrate in some links in the water distribution systems are monitored by radio or internet, and the waterhead and flowrate monitoring stations are usually determined by experience or simply evenly distributed. For the purpose of more efficient monitoring, optimal monitoring of waterhead in a water distribution system was developed by the authors, and as the second part of the study, this paper has proposed a method for optimal monitoring of flowrate in a water distribution system. A perturbation analysis is conducted to determine the sensitivity matrix, and the sensitivity equation is solved by a least square method, and the optimal monitoring of flowrate is then decided. The optimal monitoring solution is compared with the evenly distributed case, and it is found the optimal monitoring provides a more efficient and practical scheme if the number of monitoring stations is specified.

Xiao, Di; Liang, Jianwen; Zhao, Xinhua; Zhang, Hongwei

2004-07-01

225

Towards a Distributed Crisis Response Communication System  

Microsoft Academic Search

Reliable communication systems are one of the key success factors for a successful first response mission. Current crisis response communication systems suffer from damaged or destroyed infrastructure or are just overstressed in the case of a large scale disaster. We provide an outline for a distributed communication approach, which fulfills the requirements of first responders. It is based on a

Dirk Bradler; TU Darmstadt; Benjamin Schiller; Erwin Aitenbichler; Nicolas Liebau

226

Real Time Distributed Control Systems Using RTAI  

Microsoft Academic Search

The paper outlines the design and implementation of the Real Time Application Interface (RTAI) for Linux, as used for high performance local\\/distributed control systems implemented on low cost off the shelf general purpose computers. Its native lean real time middleware layer is described along with its use in an advanced tool to easily manage and monitor complex networked control systems.

Lorenzo Dozio; Paolo Mantegazza

2003-01-01

227

Challenges in Engineering Distributed Shipboard Control Systems  

Microsoft Academic Search

This paper presents a representative Navy shipboard control system and discusses its distributed implementa- tion. The real-time, fault t olerance and scalability as- pects are discussed; the system configuration is de- scribed; and the c omputing infrastructure is s umma- rized. The paper also p resents challenges which a re likely to be faced by the engineers of the next

Lonnie R. Welch; Binoy Ravindran; Robert D. Harrison; Leslie Madden; Michael W. Masters; Wayne Mills

1996-01-01

228

Modeling Risk in Distributed Healthcare Information Systems  

Microsoft Academic Search

This paper presents a modeling approach for performing a risk analysis study of networked healthcare information systems. The proposed method is based on CRAMM for studying the assets, threats and vulnerabilities of the distributed information system, and models their interrelationships using Bayesian networks. The most critical events are identified and prioritized, based on \\

Ilias Maglogiannis; Elias Zafiropoulos

2006-01-01

229

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.

230

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.

231

Design Considerations for Distributed Microsensor Systems  

Microsoft Academic Search

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

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

2000-01-01

232

Measurements of a Distributed File System  

Microsoft Academic Search

We analyzed the user-level file access patterns and caching behavior of the Sprite distributed file system. The first part of our analysis repeated a study done in 1985 of the: BSD UNIX file system. We found that file throughput has increased by a factor of 20 to an average of 8 Kbytes per second per active user over 10-minute intervals,

Mary G. Baker; John H. Hartman; Michael D. Kupfer; Ken W. Shirriff; John K. Ousterhout

1991-01-01

233

Performance of the Amoeba Distributed Operating System,  

National Technical Information Service (NTIS)

In the paper the authors report on the performance of the Amoeba distributed operating system. To make it into a system that can be used the authors have devoted considerable effort to providing high performance. They not only describe the performance of ...

R. van Renesse H. van Staveren A. S. Tanenbaum

1987-01-01

234

Experiences with the Amoeba Distributed Operating System.  

National Technical Information Service (NTIS)

The Amobea distributed operating system, in development and use for over eight years, is studied. The current version of the system is described in some detail, as it has evolved considerably since the first publication about it. Those aspects of the syst...

A. S. Tanenbaum R. Vanrenesse H. Vanstaveren G. J. Sharp S. J. Mullender

1989-01-01

235

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.

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

236

A New Approach to Load Flow Solutions for Radial Distribution System  

Microsoft Academic Search

This paper presents a new approach to load flow solutions for radial distribution system, in which the choice of the switches to be opened is based on the calculation of voltage at the buses, real and reactive power flowing through lines, real power losses and voltage deviation, using distribution load flow (DLF) program. In the process of load flow calculation,

T. Thakur; J. Dhiman

2006-01-01

237

Network Reconfiguration for Load Balancing in Radial Distribution Systems Using Genetic Algorithm  

Microsoft Academic Search

Network reconfiguration of a distribution system is an operation to alter the topological structure of distribution feeders by changing open \\/closed status of sectionalizing and tie switches. Network reconfiguration for time varying loads is very complex and extremely non-linear optimization, which can be effectively solved using genetic algorithm (GA). By transferring loads from the heavily loaded feeders to the lightly

P. V. Prasad; S. Sivanagaraju; N. Sreenivasulu

2007-01-01

238

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

239

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

240

A distributed microprocessing system for laboratory computing.  

PubMed

The concepts and practical implementation of a distributed processing system used for biomedical research demonstrably increase efficiency and cost effectiveness of microprocessor use. The hardware system is based on a minicomputer host and remote microcomputer slaves. Remote microcomputer systems are used for data acquisition and display, whereas the host system is used for data and program storage, as well as program compilation. The software used is the "C" programming language and the Unix operating system. Methods for programming the microcomputer in the higher level language "C" for laboratory usage are described. Examples illustrate how a distributed microprocessor system can be effectively used in a medical laboratory for the common tasks of data acquisition, processing, and display. PMID:7231225

Bourne, J R

241

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

242

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

243

Power System Information Delivering System Based on Distributed Object  

NASA Astrophysics Data System (ADS)

In recent years, improvement in computer performance and development of computer network technology or the distributed information processing technology has a remarkable thing. Moreover, the deregulation is starting and will be spreading in the electric power industry in Japan. Consequently, power suppliers are required to supply low cost power with high quality services to customers. Corresponding to these movements the authors have been proposed SCOPE (System Configuration Of PowEr control system) architecture for distributed EMS/SCADA (Energy Management Systems / Supervisory Control and Data Acquisition) system based on distributed object technology, which offers the flexibility and expandability adapting those movements. In this paper, the authors introduce a prototype of the power system information delivering system, which was developed based on SCOPE architecture. This paper describes the architecture and the evaluation results of this prototype system. The power system information delivering system supplies useful power systems information such as electric power failures to the customers using Internet and distributed object technology. This system is new type of SCADA system which monitors failure of power transmission system and power distribution system with geographic information integrated way.

Tanaka, Tatsuji; Tsuchiya, Takehiko; Tamura, Setsuo; Seki, Tomomichi; Kubota, Kenji

244

Design Patterns for Distributed Control System Benchmaking  

Microsoft Academic Search

In this paper, we describe the design and development of a simulation-agent interface for real-time distributed control system\\u000a benchmarking. This work is motivated by the need to test the feasibility of extending agent-based system to the physical device\\u000a level in manufacturing and other industrial automation systems. Our work focuses on the development of hybrid physical\\/simulation\\u000a environment that can be used

Karthik Soundararajan; Robert W. Brennan

245

A RDF Description of Distributed File Systems  

Microsoft Academic Search

The modern operating systems must integrate various Internet services, especially World-Wide Web facilities to access Web resources using file systems mechanisms. In this paper we present a high-level model describing an abstract distributed file system. The proposed description is based on Resource Description Framework (RDF) recommendation of the World-Wide Web Consortium, a standardized foundation for processing metadata. To represent the

Sabin C. Buraga

2000-01-01

246

Evolution of Quantum Entanglement in Open Systems  

SciTech Connect

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

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

2010-08-04

247

Quantum localization in open chaotic systems.  

PubMed

We study a quasibound state of a delta -kicked rotor with absorbing boundaries focusing on the nature of the dynamical localization in open quantum systems. The localization lengths xi of lossy quasibound states located near the absorbing boundaries decrease as they approach the boundary while the corresponding decay rates Gamma are dramatically enhanced. We find the relation xi approximately Gamma(-1/2) and explain it based upon the finite time diffusion, which can also be applied to a random unitary operator model. We conjecture that this idea is valid for the system exhibiting both the diffusion in classical dynamics and the exponential localization in quantum mechanics. PMID:18851192

Ryu, Jung-Wan; Hur, G; Kim, Sang Wook

2008-09-03

248

Quantum localization in open chaotic systems  

NASA Astrophysics Data System (ADS)

We study a quasibound state of a ? -kicked rotor with absorbing boundaries focusing on the nature of the dynamical localization in open quantum systems. The localization lengths ? of lossy quasibound states located near the absorbing boundaries decrease as they approach the boundary while the corresponding decay rates ? are dramatically enhanced. We find the relation ?˜?-1/2 and explain it based upon the finite time diffusion, which can also be applied to a random unitary operator model. We conjecture that this idea is valid for the system exhibiting both the diffusion in classical dynamics and the exponential localization in quantum mechanics.

Ryu, Jung-Wan; Hur, G.; Kim, Sang Wook

2008-09-01

249

Adaptive distribution system protection: Final report  

SciTech Connect

This report presents concepts, functions, and organizations of adaptive distribution system protection (ADSP) schemes. ADSP constantly monitors real time data, update relay characteristics and upper and lower bounds of control functions when required, and analyzes them to provide faster and more sensitive protection of all distribution system components and optimized control of loads, capacitors and reclosing sequence of circuit breakers and reclosers. Three proposed ADSP systems, Computer Overcurrent Relaying (COR) System, Directional Comparison Relaying (DCR) System and Differential Protective Coordination System, are discussed in detail. Evaluation of these three systems using technical, non-technical and economic parameters has led to the selection of the COR system as the most promising ADSP scheme for the following reasons: (1) it is simple to implement, (2) it uses the same protection philosophy and components currently being used by the electric utility industry and (3) it has a high-benefit-to-cost ratio. This report outlines strategies of integrating ADSP schemes into existing electric utility distribution systems. 21 refs., 19 figs., 6 tabs.

Shan, K.R.

1987-06-15

250

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

Code of Federal Regulations, 2010 CFR

...ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183...If a grounded distribution system is provided...of the number of power sources. This...Each propulsion, power, lighting, or distribution system having...

2009-10-01

251

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

Code of Federal Regulations, 2010 CFR

...ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120...If a grounded distribution system is provided...of the number of power sources. This...Each propulsion, power, lighting, or distribution system having...

2009-10-01

252

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

Code of Federal Regulations, 2010 CFR

...ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183...If a grounded distribution system is provided...of the number of power sources. This...Each propulsion, power, lighting, or distribution system having...

2010-10-01

253

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

Code of Federal Regulations, 2010 CFR

...ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120...If a grounded distribution system is provided...of the number of power sources. This...Each propulsion, power, lighting, or distribution system having...

2010-10-01

254

46 CFR 28.855 - Electrical distribution systems.  

Code of Federal Regulations, 2010 CFR

...Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must...or conductor grounded. (b) A grounded electrical distribution system must have only one connection to ground....

2009-10-01

255

46 CFR 28.360 - Electrical distribution systems.  

Code of Federal Regulations, 2010 CFR

...Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must...or conductor grounded. (b) A grounded electrical distribution system must have only one connection to ground....

2009-10-01

256

46 CFR 28.360 - Electrical distribution systems.  

Code of Federal Regulations, 2010 CFR

...Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must...or conductor grounded. (b) A grounded electrical distribution system must have only one connection to ground....

2010-10-01

257

47 CFR 73.626 - DTV distributed transmission systems.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false DTV distributed transmission systems. 73.626 Section 73...Stations § 73.626 DTV distributed transmission systems. (a) A DTV station...Such operation is called a distributed transmission system (DTS). Except as...

2012-10-01

258

47 CFR 73.6023 - Distributed transmission systems.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Distributed transmission systems. 73.6023 Section 73...Stations § 73.6023 Distributed transmission systems. Station licensees...television channel in a distributed transmission system. [73 FR 74064, Dec....

2012-10-01

259

47 CFR 73.626 - DTV distributed transmission systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false DTV distributed transmission systems. 73.626 Section 73...Stations § 73.626 DTV distributed transmission systems. (a) A DTV station...Such operation is called a distributed transmission system (DTS). Except as...

2011-10-01

260

47 CFR 73.6023 - Distributed transmission systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Distributed transmission systems. 73.6023 Section 73...Stations § 73.6023 Distributed transmission systems. Station licensees...television channel in a distributed transmission system. [73 FR 74064, Dec....

2011-10-01

261

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

262

46 CFR 28.360 - Electrical distribution systems.  

Code of Federal Regulations, 2011 CFR

...Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor grounded. (b) A grounded electrical distribution system must have only one connection to...

2011-10-01

263

46 CFR 28.855 - Electrical distribution systems.  

Code of Federal Regulations, 2011 CFR

...Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor grounded. (b) A grounded electrical distribution system must have only one connection to...

2011-10-01

264

46 CFR 28.360 - Electrical distribution systems.  

Code of Federal Regulations, 2012 CFR

...Electrical distribution systems. (a) Each electrical distribution system which has a neutral bus or conductor must have the neutral bus or conductor grounded. (b) A grounded electrical distribution system must have only one connection to...

2012-10-01

265

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

266

Switch placement to improve system reliability for radial distribution systems with distributed generation  

Microsoft Academic Search

To improve system reliability for radial distribution systems with distributed generation (DG) under fault conditions, switch placement schemes are proposed to form self-supported areas after fault isolation. Customer priority is also considered in this problem. The switch placement problem is formulated as a nondifferentiable, multiobjective optimization problem. Graph-based algorithms, which incorporate direct load control, are developed to locate switches. Their

Yiming Mao; Karen N. Miu

2003-01-01

267

A review of distributed power systems part I: DC distributed power system  

Microsoft Academic Search

The present development state in DC distributed power systems (DPS) is comprehensively reviewed in this tutorial. Basic distributed structures and their characteristics are described. The system level design considerations are discussed. The profile of current technologies is drawn. Finally, the issues and challenges in this research area are identified. These issues include not only improving efficiency, but also increased concerns

Shiguo Luo; ISSA BATARSEH

2005-01-01

268

Specific heat anomalies of open quantum systems.  

PubMed

The evaluation of the specific heat of an open damped quantum system is a subtle issue. One possible route is based on the thermodynamic partition function which is the ratio of the partition functions of system plus bath and of the bath alone. For the free damped particle it has been shown, however, that the ensuing specific heat may become negative for appropriately chosen environments. Being an open system this quantity then naturally must be interpreted as the change in the specific heat obtained as the difference between the specific heat of the heat bath coupled to the system degrees of freedom and the specific heat of the bath alone. While this difference may become negative, the involved specific heats themselves are always positive; thus, the known thermodynamic stability criteria are perfectly guaranteed. For a damped quantum harmonic oscillator, instead of negative values, under appropriate conditions one can observe a dip in the difference of specific heats as a function of temperature. Stylized minimal models containing a single oscillator heat bath are employed to elucidate the occurrence of the anomalous temperature dependence of the corresponding specific heat values. Moreover, we comment on the consequences for the interpretation of the density of states based on the thermal partition function. PMID:19658471

Ingold, Gert-Ludwig; Hänggi, Peter; Talkner, Peter

2009-06-09

269

Specific heat anomalies of open quantum systems  

NASA Astrophysics Data System (ADS)

The evaluation of the specific heat of an open damped quantum system is a subtle issue. One possible route is based on the thermodynamic partition function which is the ratio of the partition functions of system plus bath and of the bath alone. For the free damped particle it has been shown, however, that the ensuing specific heat may become negative for appropriately chosen environments. Being an open system this quantity then naturally must be interpreted as the change in the specific heat obtained as the difference between the specific heat of the heat bath coupled to the system degrees of freedom and the specific heat of the bath alone. While this difference may become negative, the involved specific heats themselves are always positive; thus, the known thermodynamic stability criteria are perfectly guaranteed. For a damped quantum harmonic oscillator, instead of negative values, under appropriate conditions one can observe a dip in the difference of specific heats as a function of temperature. Stylized minimal models containing a single oscillator heat bath are employed to elucidate the occurrence of the anomalous temperature dependence of the corresponding specific heat values. Moreover, we comment on the consequences for the interpretation of the density of states based on the thermal partition function.

Ingold, Gert-Ludwig; Hänggi, Peter; Talkner, Peter

2009-06-01

270

Minimizing the impact of distributed generation on distribution protection system by solid state fault current limiter  

Microsoft Academic Search

Connection of new distributed generation (DG) to the existing distribution network increases the fault current and disturbs the existing distribution protection system. In this paper a solid state fault current limiter (SSFCL) application is proposed to minimize the effect of the DG on the distribution protection system in a radial system during a fault. The protection problems at distributed generation

S. A. A. Shahriari; M. Abapour; A. Yazdian; M. R. Haghifam

2010-01-01

271

Distributed intrusion detection system based on ARTIS  

NASA Astrophysics Data System (ADS)

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

Qiao, Peili; Su, Jie; Sun, Chengwei

2005-03-01

272

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

273

Parameter adaptive control of stochastic distributed systems  

Microsoft Academic Search

The parameter adaptive control problem of linear stochastic distributed-parameter systems is considered and treated by invoking the partitioning\\/non-linear separation approach. Both continuous-time and discrete-time systems are studied, with volume and\\/or boundary control and disturbance inputs. The following cases are considered: spatially-continuous and point-wise measurements\\/control actions, continuous and quantized parameter space, non-gaussian initial state, uncertainty in continuous and point-wise measurements, cost-function

S. G. TZAFESTAS

1980-01-01

274

UBC DISTRIBUTED CONTINUOUS MEDIA FILE SYSTEM  

Microsoft Academic Search

Abstract This report describes the internal design of the UBC Distributed Continuous Media File Server as of April 1995. The most significant unique characteristic of this system is its approach,to admission control which,utilizes the time-varying requirements,of the variable bit-rate data streams currently admitted into the system to properly allocate disk resources. The structure of the processes which implement,the file server

Dwight J. Makaroff; Norman C. Hutchinson; Gerald W. Neufeld

275

Security Enhancements for Distributed Control Systems  

Microsoft Academic Search

Security enhancements for distributed control systems (DCSs) must be sensitive to operational issues, especially availability.\\u000a This paper presents three security enhancements for DCSs that satisfy this requirement: end-to-end security for DCS protocol\\u000a communications, role-based authorization to control access to devices and prevent unauthorized changes to operational parameters,\\u000a and reduced operating system kernels for enhanced device security. The security enhancements have

Jeffrey L. Hieb; James H. Graham; Sandip C. Patel

2007-01-01

276

Graphical user interfaces for heterogeneous distributed systems  

NASA Astrophysics Data System (ADS)

In modern object-oriented computer systems the internal state of the entire system consists of the internal states of many objects, probably distributed over a heterogeneous network of computers. The man machine interaction in such an application is based on the visualization of states on one hand and the modification of states in combination with event generation on the other hand. This paper describes concept and realization of a reusable service for general man machine communication.

Brinkschulte, Uwe; Siormanolakis, Marios; Vogelsang, Holger

1996-03-01

277

Interconnecting a distributed processor system for avionics  

Microsoft Academic Search

This paper describes the interconnection scheme devised for an advanced Air Force system concept called Distribution Processor\\/Memory (DP\\/M) in which topologically irregular networks of small computers are used to perform avionics processing. The interconnection scheme involves the use of a combination of global and point-to-point busses to handle message traffic in predominantly homogeneous systems of from 5 to 20 computers.

George A. Anderson

1973-01-01

278

DC microgrid based distribution power generation system  

Microsoft Academic Search

This paper describes an autonomous-control method for a DC microgrid system having distribution power generators. This system consists of following five generation and control units; a solar-cell generation unit, a wind-turbine generation unit, a battery energy-storage unit, a flywheel power-leveling unit, and an AC grid-connected power control unit. The proposed control method intended for suppression of circulating current detects only

Y. Ito; Y. Zhongqing; H. Akagi

2004-01-01

279

DISTRIBUTION SYSTEM RELIABILITY ANALYSIS USING A MICROCOMPUTER  

EPA Science Inventory

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

280

Multiple Systems of Distribution for Street Lighting  

Microsoft Academic Search

The wider use of multiple lamps supplied from standard secondary distribution systems is considered as a step in simplifying operating problems and reducing the disporportionate cost which goes to cover fixed charges on special equipment and additional lines for street lighting only. The advantages in simplicity and flexibility of multiple connected lamps are discussed with particular reference to the frequent

Ward Harrison

1920-01-01

281

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

282

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

283

Distributed Control System for a Humanoid Robot  

Microsoft Academic Search

A humanoid robot generally has more than thirty DOFs to be controlled in real-time and needs to deal with information of multiple sensors such as encoders, force, gyro, acceleration and vision sensors. Therefore an effective control system is crucial for the humanoid robot. In this paper, we propose a distributed control architecture for humanoid robots based on the combination of

Zhangguo Yu; Qiang Huang; Jianxi Li; Qing Shi; Xuechao Chen; Kejie Li

2007-01-01

284

Overcurrent protection alternatives for underground distribution systems  

Microsoft Academic Search

Pad-Mounted Switchgear that is applied on underground distribution systems effects many aspects of electric utility service. Some of these include overcurrent protection characteristics, the ability of the line service crews to quickly restore service after a fault, the overall reliability of service to the customer, and, to some degree, the cost of the electric service to the customer. The user

M. T. Bishop; A. G. Jones; W. F. Israel

1995-01-01

285

Distributed Computation as an Economic System  

Microsoft Academic Search

As computer networks grow and blanket the planet, they become a community of concurrent processes, which, in their interactions, strategies, and lack of perfect knowledge, become analogous to human market economies. Economics may thus offer new ways of designing and understanding the behavior of distributed computer systems. Copyright 1995 by American Economic Association.

Bernardo A Huberman; Tad Hogg

1995-01-01

286

Process Partitioning for Distributed Embedded Systems  

Microsoft Academic Search

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

Junwei Hou; Wayne Wolf

1996-01-01

287

Quality monitoring in clock synchronized distributed systems  

Microsoft Academic Search

Clock synchronization in distributed computer systems is an enabler for the introduction of real-time. So far, many approaches are published which implement clock synchronization on a protocol basis over state of the art packet oriented networks. One very recent example is the introduction of real-time into industrial Ethernet net- works, like in Profinet or Powerlink. In addition to this usually

Georg Gaderer; Patrick Loschmidt; Thilo Sauter

2006-01-01

288

Bias in parallel and distributed simulation systems  

Microsoft Academic Search

Even after several decades of research, modeling is considered an art, with a high liability to produce incorrect abstractions of real world systems. Therefore, validation and verification of simulation models is considered an indispensable method to establish the credibility of developed models. In the process of parallelizing or distributing a given credible simulation model, a bias is introduced, possibly leading

Tobias Kiesling; R. E. A. Khayari; J. Luthi

2005-01-01

289

Bias in parallel and distributed simulation systems  

Microsoft Academic Search

Even after several decades of research, modeling is con- sidered an art, with a high liability to produce incorrect abstractions of real world systems. Therefore, validation and verification of simulation models is considered an in- dispensable method to establish the credibility of developed models. In the process of parallelizing or distributing a given credible simulation model, a bias is introduced,

Tobias Kiesling; Johannes Lüthi; Rachid El Abdouni Khayari

2005-01-01

290

Composite fault location for Distribution Management Systems  

Microsoft Academic Search

The problem of fault location is an integral part of Distribution Management System (DMS) solutions. This paper presents a method of locating fault in unsymmetrical networks, including both radial and meshed parts of the network. The real-time information regarding the topological condition of the network and the status updates of the Fault Indicators are used as input to the fault

I. Dzafic; P. Mohapatra; H. T. Neisius

2010-01-01

291

Management policy service for distributed systems  

Microsoft Academic Search

Interpreting policy in automated managers facilitates the dynamic change of behaviour of a distributed management system by simply changing policies. This paper describes a management policy notation which can be used to define both authorisation policies (what activities a manager is permitted to do) and obligation policies (the activities a manager must perform). Some example policy specifications are given to

Damian Marriott; Morris Sloman

1996-01-01

292

MANAGEMENT POLICY SERVICE FOR DISTRIBUTED SYSTEMS  

Microsoft Academic Search

Interpreting policy in automated managers facilitates the dynamic change of behaviour of a distributed management system by simply changing policies. This paper describes a management policy notation which can be used to define both authorisation policies (what activities a manager is permitted to do) and obligation policies (the activities a manager must perform). Some example policy specifications are given to

Damian A. Marriott; Morris S. Sloman; Nicholas Yialelis

1995-01-01

293

DISTRIBUTION SYSTEM: COST OF REPAIR AND REPLACEMENT  

EPA Science Inventory

The Safe Drinking Water Act of 1974 mandates that EPA be concerned with the supply of potable water to the consumer. Although most emphasis has been placed on water quality as it leaves the treatment plant interest is increasing in the role of the distribution system in causing w...

294

MANAGEMENT OF WATER DISTRIBUTION SYSTEM COMPONENTS  

EPA Science Inventory

The purpose of the study is to (1) analyze main break failures and (2) incorporate other drinking water distribution system components into a data base management structure for reliability analyses. Reliability analysis should be a part of an overall operation and maintenance str...

295

Velocity distribution measurement with oculomotor system  

Microsoft Academic Search

In this paper we propose a method of measuring velocity distribution with oculomotor system by using spatiotemporal differentiation. The velocity of the moving pattern is measured by spatiotemporal differentiations. It has been difficult to derive velocity by the spatiotemporal method when the moving pattern displacement between frames becomes large. It is shown that we can expand the measurable velocity range

Hideaki Takahashi; Teruo Yamaguchi; Hiroshi Harada

2007-01-01

296

Authentication in distributed systems: a bibliography  

Microsoft Academic Search

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

Armin Liebl

1993-01-01

297

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

298

Planform development of distributed, sheet-like subglacial water systems  

NASA Astrophysics Data System (ADS)

Planform configuration of a subglacial drainage system plays a crucial role in determining how these systems affect the overlying ice. Drainage helps control coupling between a glacier and its underlying bed. Systems that are deep relative to bed roughness and distribute water can increase slip rates. Shallow or coalescent water systems can couple ice and bed and lower slip rates of an overlying glacier. Whether the system is distributed or coalescent typically depends on how quickly water moves subglacially as well as its supply rate. Rates of water evacuation are governed by gradients driving flow and system transmissivity. Transmissivity is governed by effective pressure that determines closure rates and hydraulic gradient that determines melt rates that open the system. Work by Creyts and Schoof [2009] using a simple model shows that the transmissivity is not necessarily monotonic in subglacial systems but can be a multi-valued function of both closure and melt. A simplification in their formulation is the lack of an along-path water balance. We extend their work to show how the along-path water balance acts to form a distributed subglacial network and give planform geometry. Switches between different branches of the water depth relationship correspond to either the establishment or shut-down of a ‘connected’ drainage system and yield either more or less hydraulically conductive areas of the subglacial system. We show how along-path discharge affects water depth and spatial switches from one state to another. We conclude by discussing state behavior relative to subglacial conditions beneath present ice sheets.

Creyts, T. T.; Schoof, C.

2010-12-01

299

Data reprocessing on worldwide distributed systems  

SciTech Connect

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

Wicke, Daniel; /Fermilab

2004-12-01

300

Data reprocessing on worldwide distributed systems  

SciTech Connect

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

Diesburg, Mike; Wicke, Daniel; /Fermilab

2004-12-01

301

Scheduling parallel programs in distributed systems  

SciTech Connect

Scheduling parallel programs under the processor-sharing discipline for uniprocessors, multiprocessors, and distributed systems was studied. Two classes of parallel programs are considered: those without any IPC (called Fork-Join jobs) and those with asynchronous and uniform IPC (called clusters). The study is divided into two parts: (1) develops analytical solutions for Fork-Join Jobs on uniprocessors and multiprocessors; and (2) develops and evaluates via simulation Fork-Join jobs and clusters on distributed systems. The types of site scheduling studied are TS-PS where tasks of a job are scheduled independently at processor-sharing servers, JS-PS in which tasks of a job are scheduled as a single entity at processor-sharing servers, and FCFS where tasks of a job are scheduled independently by order of arrival. For Poisson job arrivals and exponentially distributed task service times, analytical solutions and computationally efficient bounds were found for Fork-Join TS-PS and JS-PS job response times. An algorithm was developed to schedule parallel programs in distributed systems. Over a wide range of parameters the algorithms was found to be superior to both no-load balancing, NLB, and shortest-queue first scheduling, SQF.

Rommel, C.G.

1988-01-01

302

A Novel Framework for Building Distributed Data Acquisition and Monitoring Systems  

Microsoft Academic Search

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

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

2007-01-01

303

High-performance computing and distributed systems  

SciTech Connect

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

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

1992-09-01

304

High-performance computing and distributed systems  

SciTech Connect

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

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

1992-09-01

305

Spectroscopic studies in open quantum systems  

PubMed

The Hamiltonian H of an open quantum system is non-Hermitian. Its complex eigenvalues E(R) 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 neighboring resonance states. Level repulsion may occur along the real or imaginary axis (the latter is called resonance trapping). In any case, the eigenvalues of the two states avoid crossing in the complex plane. We then calculate the poles of the S matrix and the corresponding wave functions 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 waveguide. The calculations are performed by using the method of exterior complex scaling. Re(H) and Im(H) cause changes in the structure of the wave functions which are permanent, as a rule. 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 effects arising from the interplay between resonance trapping and level repulsion along the real axis are not involved in the statistical theory (random matrix theory). PMID:11088480

Rotter; Persson; Pichugin; Seba

2000-07-01

306

14 CFR 23.1445 - Oxygen distribution system.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Oxygen distribution system. 23.1445 Section...AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC...Equipment § 23.1445 Oxygen distribution system. (a) Except... (b) Nonmetallic oxygen distribution lines must not be...

2013-01-01

307

Quantum Speed Limits in Open System Dynamics  

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

308

Quantum speed limits in open system dynamics.  

PubMed

Bounds to the speed of evolution of a quantum system are of fundamental interest in quantum metrology, quantum chemical dynamics, and quantum computation. We derive a time-energy uncertainty relation for open quantum systems undergoing a general, completely positive, and trace preserving evolution which provides a bound to the quantum speed limit. When the evolution is of the Lindblad form, the bound is analogous to the Mandelstam-Tamm relation which applies in the unitary case, with the role of the Hamiltonian being played by the adjoint of the generator of the dynamical semigroup. The utility of the new bound is exemplified in different scenarios, ranging from the estimation of the passage time to the determination of precision limits for quantum metrology in the presence of dephasing noise. PMID:23414008

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

2013-01-30

309

Feshbach projection formalism for open quantum systems.  

PubMed

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

Chru?ci?ski, Dariusz; Kossakowski, Andrzej

2013-07-30

310

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

311

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

312

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

313

A Novel Method for Optimal Distributed Generator Placement in Radial Distribution Systems  

Microsoft Academic Search

Optimal placement of distributed generators is essential, as inappropriate placement may increase the system losses. This article proposes a novel methodology for finding the optimal size and location for installation of Distributed Generators (DGs) so as to minimize total power losses in radial distribution systems. Distribution load flow is used to find the power loss in the system. The Proposed

Sri K. Nagaraju; S. Sivanagaraju; T. Ramana; S. Satyanarayana; P. V. Prasad

2011-01-01

314

Distance protection in distribution systems: How it assists with integrating distributed resources  

Microsoft Academic Search

The integration of distributed generation (DG) or distributed resources in the distribution system poses technical constraints for the electrical power system owner or manager. The addition of relatively large amounts of generation to the distribution system can potentially challenge the historical settings principles and design assumptions made in developing protection and control strategies based on overcurrent protection. The necessity and

David Martin; Pankaj Sharma; Amy Sinclair; Dale Finney

2012-01-01

315

Fault Location in Power Distribution System With Penetration of Distributed Generation  

Microsoft Academic Search

It has been shown that coordination between protec- tive devices in distribution systems in the presence of significant distributed generation (DG) will be disrupted. With the recent trend of adopting and integrating renewable resources and mi- crogrids with distribution systems, it is probable that distribution systems will have significant and arbitrary penetration of DG in the near future. This will

Sukumar M. Brahma

2011-01-01

316

Diradical character dependences of the first and second hyperpolarizabilities of asymmetric open-shell singlet systems  

NASA Astrophysics Data System (ADS)

The static first and second hyperpolarizabilities (referred to as ? and ?, respectively) of asymmetric open-shell singlet systems have been investigated using the asymmetric two-site diradical model within the valence configuration interaction level of theory in order to reveal the effect of the asymmetric electron distribution on the diradical character and subsequently on ? and ?. It is found that the increase of the asymmetric electron distribution causes remarkable changes in the amplitude and the sign of ? and ?, and that their variations are intensified with the increase of the diradical character. These results demonstrate that the asymmetric open-shell singlet systems with intermediate diradical characters can exhibit further enhancements of ? and ? as compared to conventional asymmetric closed-shell systems and also to symmetric open-shell singlet systems with intermediate diradical characters.

Nakano, Masayoshi; Champagne, Benoît

2013-06-01

317

Odorant loss in natural gas distribution systems  

SciTech Connect

The loss of odorant compounds (odor fading) was studied using flow reactors which simulated the typical operating conditions of a gas distribution system. A unique method was developed to simulate rust on the inside surface of the pipeline. The study indicated that odorant loss can be impacted by the following operating parameters: Pressure; Temperature; Velocity; Iron oxide compounds; Thickness of iron oxide layer in pipe.

Moran, E.A.; Pai, P.G.; Carducci, M.I. (Lab. Services, Dept. of Engineering Activity, Michigan Consolidated Gas Co., MI (US))

1991-04-01

318

Electric power distribution and load transfer system  

SciTech Connect

This patent describes a power distribution system. It comprises at least two switch means for controlling the application of power from a power source to a power output; at least two current means for preventing reverse power flow through respective ones of switch means; and processing means for providing control signals to operate the switch means, effective to switch respective ones of the power sources between on and off states with respect to the power output.

Bradford, M.P.; Parkinson, G.W.; Grant, R.M.

1989-10-10

319

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

320

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

321

Distributed simulation for power system analysis including shipboard systems  

Microsoft Academic Search

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

Jian Wu; Noel N. Schulz; Wenzhong Gao

2007-01-01

322

Approach Light System (ALS) Multiple Distribution System Redesign.  

National Technical Information Service (NTIS)

The effort is an attempt, without sacrificing reliability, to provide a lower cost Approach Lght System (ALS) distribution system by changing from the present series output circuits to a multiple type with constant voltage and using parallel step-down tra...

R. P. Marek

1974-01-01

323

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

324

Neutron chain length distributions in subcritical systems  

SciTech Connect

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

Nolen, S.D.; Spriggs, G.

1999-09-27

325

Quantum response of dephasing open systems  

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

326

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

Microsoft Academic Search

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

J. Ozols

1997-01-01

327

Pseudorational Impulse Responses — Algebraic System Theory for Distributed Parameter Systems  

NASA Astrophysics Data System (ADS)

This paper gives a comprehensive account on a class of distributed parameter systems, whose impulse response is called pseudorational. This notion was introduced by the author in 1980's, and is particularly amenable for the study of systems with bounded-time memory. We emphasize algebraic structures induced by this class of systems. Some recent results on coprimeness issues and H? control are discussed and illustrated.

Yamamoto, Yutaka

328

Optimizing Location and Sizing of Distributed Generation in Distribution Systems  

Microsoft Academic Search

Recent changes in the electric utility infrastructure have create opportunities for many technological innovations, including the employment of distributed generation (DG) to achieve a variety of benefits. Both utility and customers benefit from DG. Among the many benefits of distributed generation, there are many directions to solve problem of DG but all also want to accomplish to achieve the optimality

T. Q. D. Khoa; P. T. T. Binh; H. B. Tran

2006-01-01

329

The application of Open System Architecture to planetary surface systems  

NASA Astrophysics Data System (ADS)

The issues that future planet surface activities must confront are explored, the basic concepts that provide the basis for establishing an Open System Architecture (OSA) are defined, the appropriate features of such an architecture are identified, and examples of OSAs are discussed. OSAs are designed to provide flexibility and evolutionary growth of planet surface systems to support the users needs. An OSA is based on two fundamental principles: precise definition of component functionality and the establishment of standards. An OAS must be functionally decomposed, top down, to identify all functions, subfunctions, subsubfunctions, etc., that are required to be performed by the system. There is an allocation of function, or process, to components. The functional packaging within a component becomes the user's primary perception of the system. The standards of an OSA enable the user to attain the full functional capabilities inherent in the system.

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

330

Smart distribution system design: Automatic reconfiguration for improved reliability  

Microsoft Academic Search

This paper explores distribution system automation, automatic reconfiguration after a disturbance and the impact on reliability in a `smart' power distribution system. The use of network incidence or connectivity matrices is shown and an example indicates the potential operational capabilities of a `smart distribution system'. A discussion of the potential advantages of electronic switching in distribution engineering is also given.

D. Haughton; G. T. Heydt

2010-01-01

331

A simple algorithm for unbalanced radial distribution system load flow  

Microsoft Academic Search

Many programs of real-time applications in the area of distribution automation, such as network optimization, Var planning, switching, state estimation, and so forth, require a robust and efficient load flow method for distribution systems. Such a load flow method must be able to model the special features of distribution systems in sufficient detail. Many approaches for unbalanced radial distribution system

Sivkumar Mishra

2008-01-01

332

Scry: A distributed image handling system  

SciTech Connect

Scry is a distributed image handling system that provides both image compression and transport on local and wide area networks, and a collection of higher level graphics and scientific visualization functions. The system can be distributed among workstations, between supercomputers and workstations, and between supercomputers, workstations and video animation controllers. The system is most commonly used to produce video based movie displays of time dependent data and complex 3D data sets, and to handle the images resulting from certain image processing operations. In the scientific visualization process, the system is typically used in one of two configurations. In the first, the supercomputer application generates data (e.g., flow field vectors) that are compressed and sent to a graphics workstation over a wide area network. The graphics workstation environment is used to design and debug the graphics visualization for a movie. Finally, the raster images that represent the frames of the movie are compressed and sent over a local area network to the video animation controller. This report discusses the use of this program.

Robertson, D.W.; Johnston, W.E.; Chua, Teck-Joo; Huang, J.; Renema, F.; Rible, M.; Texier, N.; Wishinsky, B.J.

1989-04-01

333

Development of adaptive protection scheme for distribution systems with high penetration of distributed generation  

Microsoft Academic Search

Conventional power distribution system is radial in nature, characterized by a single source feeding a network of downstream feeders. Protection scheme for distribution system, primarily consisting of fuses and reclosers and, in some cases, relays, has traditionally been designed assuming the system to be radial. After connecting distributed generation (DG), part of the system may no longer be radial, which

Sukumar M. Brahma; Adly A. Girgis

2004-01-01

334

Active Coordinated Operation of Distribution Network System for Many Connections of Distributed Generators  

NASA Astrophysics Data System (ADS)

Recently, total number of distributed generators (DGS) such as photovoltaic generation system and wind turbine generation system connected to an actual distribution network increases drastically. The distribution network connected with many distributed generators must be operated keeping reliability of power supply, power quality and loss minimization. In order to accomplish active distribution network operation to take advantage of many connections of DGS, a new coordinated operation of distribution system with many connections of DGS is necessary. In this paper, the authors propose a coordinated operation of distribution network system connected with many DGS by using newly proposed sectionalizing switches control, sending voltage control and computation of available DG connection capability. In order to check validity of the proposed coordinated operation of distribution system, numerical simulations using the proposed coordinated distribution system operation are carried out in a practical distribution network model.

Hayashi, Yasuhiro; Kawasaki, Shoji; Matsuki, Junya; Wakao, Shinji; Baba, Junpei; Hojo, Masahide; Yokoyama, Akihiko; Kobayashi, Naoki; Hirai, Takao; Oishi, Kohei

335

Overcurrent protection alternatives for underground distribution systems  

SciTech Connect

Pad-Mounted Switchgear that is applied on underground distribution systems effects many aspects of electric utility service. Some of these include overcurrent protection characteristics, the ability of the line service crews to quickly restore service after a fault, the overall reliability of service to the customer, and, to some degree, the cost of the electric service to the customer. The user must develop a system design philosophy and then determine the equipment features needed to help meet the goals of the chosen system design. Since these goals may vary with the type of load being served, equipment features that may be selected will be discussed for single phase and three phase services. The application benefits of pad-mounted sectionalizing switch gear, pad-mounted fused switch gear, and pad-mounted VFI switchgear will be compared in these applications.

Bishop, M.T. [Cooper Power Systems, Franksville, WI (United States). Systems Engineering Group; Jones, A.G.; Israel, W.F. [Cooper Power Systems, South Milwaukee, WI (United States). Kyle Distribution Switchgear

1995-01-01

336

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

337

Age Dependence of the Vertical Distribution of Young Open Clusters  

NASA Astrophysics Data System (ADS)

The ages of 203 open clusters from the list of Dambis (1999) are computed in terms of Cambridge evolutionary tracks with and without the allowance for convective overshooting (Pols et al. 1998). The vertical scaleheight of the cluster layer for 123 objects at Galactocentric distances R_g = R_0 ± 1 kpc is found to vary non-monotonically with age exhibiting a wavelike pattern similar to the one earlier found for the Cepheid population (Joeveer 1974). The period of these variations is equal to PZ = 74 ± 2 Myr and PZ = 92 ± 2 Myr if cluster ages are computed in terms of evolutionary models of Pols et al. (1998) without and with overshooting, respectively. If interpreted as a manifestation of vertical virial oscillations, the implications of the pattern found are threefold: (1) the period of vertical oscillations can be reconciled with the known local density of visible matter only if cluster ages are computed with no or mild overshooting (PZ = 74 ± 2 Myr), which implies a maximum local density of ? = 0.118 ± 0.006 Modot pc^{-3} compared to ? = 0.102 Modot pc^{-3} recently inferred from Hipparcos data (Holmberg & Flynn 2000), whereas the period derived from ages computed using models with overshooting (PZ = 92 ± 2 Myr) implies a maximum local density of only ? = 0.075 ± 0.003 Modot pc^{-3} and is thus totally incompatible with recent estimates; (2) there is not much room left for the dark matter (?_DM le 0.027 Modot pc^{-3}) in the Galactic disk near the solar Galactocentric distance, and (3) at the time of their formation open clusters have, on the average, excess kinetic energy (in the vertical direction) and as a population are not in virial equilibrium; moreover, the initial vertical coordinates of open clusters (at the time of their birth) are strongly and positively correlated with initial vertical velocities (the correlation coefficient is r(Z_0,V_{Z(0)}) = 0.81 ± 0.08), thus favoring a scenario where star formation in the disk is triggered by some massive objects falling to the Galactic plane.

Dambis, A. K.

338

A DEVELOPMENT FRAMEWORK FOR OPEN SERVICE MANAGEMENT SYSTEMS  

Microsoft Academic Search

Management systems for communication services operate in a competitive, multi-domain environment in which open interfaces are essential for service providers in order to interoperate with customers and other service providers. Open interfaces and framework agreements are also required to take advantage commercial off the shelf components and so reduce the costs and time taken in management system development. This paper

David Lewis

1999-01-01

339

A Power Systems Analysis Software Package For Open Electricity Markets  

Microsoft Academic Search

This paper reports a power system analysis tool with particular emphasis on its application in open electricity markets. Traditionally, vertically integrated utilities are planned and operated to provide generation to meet load demand in an economical and reliable manner. With the emergence of open electricity market, power systems have become more complex because utilities have to desegregate to promote competition

Joseph N. Y. Cheung

2006-01-01

340

A model for open architecture mission control systems  

NASA Astrophysics Data System (ADS)

A model is described which provides a theoretical underpinning open systems view of Mission Control. Various Facets of the open ecosystem approach are described as are their interactions. A hypothesis is put forward that Mission Control flexibility is best achieved not by vertically integrated systems but through a new model which tracks the IT industry's evolution.

Pavlick, Timothy J.

2013-05-01

341

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

2012-10-15

342

Trust and Partial Typing in Open Systems of Mobile Agents (Extended Abstract)  

Microsoft Academic Search

We present a partially-typed semantics for D?, a distributed ?- calculus. The semantics is designed for mobile agents in open dis- tributed systems in which some sites may harbor malicious inten- tions. Nonetheless, the semantics guarantees traditional type-safety properties at \\

James Riel; Matthew Hennessy

1999-01-01

343

Wireless Clock Distribution System Using an External Antenna  

Microsoft Academic Search

A compact wireless clock distribution system with an external planar array antenna which can provide phase and amplitude distributions suitable for synchronizing circuits over a 35-mm diameter circular area at 3 GHz is proposed. The computer systems using this wireless clock distribution can have a comparable form factor as systems using a conventional clock network. The system is composed of

Ran Li; Xiaoling Guo; Dong-Jun Yang; K. O. Kenneth

2007-01-01

344

Broadcasting Systems: An Advanced CATV System with Wireless Distribution  

NASA Astrophysics Data System (ADS)

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

Tsuzuku, Aiichiro

2001-12-01

345

A fuzzy genetic approach for network reconfiguration to enhance voltage stability in radial distribution systems  

Microsoft Academic Search

This paper presents a fuzzy genetic approach for reconfiguration of radial distribution systems (RDS) so as to maximize the voltage stability of the network for a specific set of loads. The network reconfiguration involves a mechanism for selection of the best set of branches to be opened, one from each loop, such that the reconfigured RDS possesses desired performance characteristics.

N. C. Sahoo; K. Prasad

2006-01-01

346

A Cooperative Simulation Mechanism of Distributed Control Systems Based on Object-Oriented Design Pattern  

Microsoft Academic Search

Distributed control systems (DCSs) consisting of a plant, a controller composed of many devices, and an open network interconnecting devices, are now used in many automation areas. For assuring the control performance under the heavy traffic on the network, the simulation of DCS is strongly needed. In the case of DCSs for controlling a mechanical plant, the graphical and cooperative

Toyoaki Tomura; Satoshi Kanai; Takeshi Kishinami

2003-01-01

347

In Pursuit of Correct Paradigms for Object-Oriented Real-Time Distributed Systems  

Microsoft Academic Search

Real time distributed applications based on object oriented technology raise many complex issues, most of them still open. We elaborate on the reasons why traditional paradigms, found adequate for tackling simple problems, cannot help in addressing these complex issues. A detailed illustration is given with a problem in modular avionics, which has been addressed by resorting to proof based system

Patrice Carrére; Jean-françois Hermant; Gérard Le Lann

1999-01-01

348

Personal Computers for Real-Time Control of Power System Distribution Networks  

Microsoft Academic Search

Personal computers offer a new way to design low-price, real-time supervisory control and data aquisition (SCADA) systems. The concept open up new areas of application by providing computerized control where it previously was unrealistic due. to the cost. Computerized control of distribution level networks is thus possible.

Ulf Sandberg; Hats Faxer

1984-01-01

349

A distributed system for fast alignment of next-generation sequencing data  

Microsoft Academic Search

We developed a scalable distributed computing system using the Berkeley Open Interface for Network Computing (BOINC) to align next-generation sequencing (NGS) data quickly and accurately. NGS technology is emerging as a promising platform for gene expression analysis due to its high sensitivity compared to traditional genomic microarray technology. However, despite the benefits, NGS datasets can be prohibitively large, requiring significant

Jaydeep K. Srimani; Po-Yen Wu; John H. Phan; May D. Wang

2010-01-01

350

Active Loss Allocation Systems in Radial Distribution Systems  

Microsoft Academic Search

In the restructured power system under deregulation, proper pricing of electricity has emerged as a key issue. The cost of transmission and distribution activities needs to be allocated to the users of these networks. Among others, power losses are one of the costs to be allocated. The main difficulty faced in allocating losses is the nonlinearity between the losses and

Sivkumar Mishra; Debapriya Das; Subrata Paul

2010-01-01

351

Distributed fiber optic moisture intrusion sensing system  

DOEpatents

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

Weiss, Jonathan D. (Albuquerque, NM)

2003-06-24

352

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

Microsoft Academic Search

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

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

1990-01-01

353

Impact of Distributed Generators on Protective Devices in Radial Distribution Systems  

Microsoft Academic Search

Proper protection of distribution systems is essential to ensure high reliability and power quality. With the proposed migration to the inclusion of distributed generation in distribution systems, it is critical that the protection schemes be adapted to address these new and very different system characteristics. The authors of this paper have studied the impact of the integration of DGs in

Karen L. Butler-Purry; Matthew Marotti

2006-01-01

354

Water Quality Deterioration in Distribution Systems Part 2: Microbial Processes in Distribution Mains  

Microsoft Academic Search

Summary: Part 1 of this series summarized the early development of scientific understanding of the role of microorganism s in water distribution systems. The earliest concerns were for the transmission of disease by organisms which penetrated the distribution system. By mid- century, an understanding of need for the maintenance of a bacteriostatic disinfectant residual in the distribution system was well

Thomas L. O'Connor; John T. O'Connor

355

A New Power Flow Method in Radial Distribution Systems  

Microsoft Academic Search

In this paper, a new efficient method is proposed for power flow calculation in radial distribution systems. The distribution busines is changing the need to plan and respond to technical change, growth in distributed generation and deregulated power markets. Thus, it is important to improve fundamental analytical tools in distribution systems. This paper proposes a new method for the power

Wataru Ohyoshi; Hiroyuki Mori

2006-01-01

356

Contextualizing normative open multi-agent systems  

Microsoft Academic Search

Open MASs can be extremely dynamic due to heterogeneous agents that migrate among them to obtain resources or services not found locally. In order to prevent malicious actions and to ensure agent trust, open MAS should be enhanced with normative mechanisms. However, it is not reasonable to expect that foreign agents know in advance all the norms of the MAS

Carolina Howard Felicíssimo; Caroline Chopinaud; Jean-pierre Briot; Amal El Fallah-seghrouchni; Carlos José Pereira De Lucena

2008-01-01

357

Investigating Advances in the Acquisition of Systems Based on Open Architecture and Open Source Software.  

National Technical Information Service (NTIS)

In 2007-08, we began an investigation of problems, issues, and opportunities that arise during the acquisition of software systems that rely on open architectures and open source software. The current effort funded for 2009-10 (funding received in 2010) s...

H. Asuncion T. A. Alspaugh W. Scacchi

2011-01-01

358

Definitions and Requirements for Distributed Real-Time Systems.  

National Technical Information Service (NTIS)

The performance parameters are defined for distributed real-time control systems and the differences in requirements are described between these and the other major categories of distributed real-time systems: resource sharing. Examples of explicit values...

C. Berggren

1988-01-01

359

49 CFR 192.747 - Valve maintenance: Distribution systems.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Valve maintenance: Distribution systems. 192...SAFETY STANDARDS Maintenance § 192.747 Valve maintenance: Distribution systems. (a) Each valve, the use of which may be necessary...

2011-10-01

360

49 CFR 192.747 - Valve maintenance: Distribution systems.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Valve maintenance: Distribution systems. 192...SAFETY STANDARDS Maintenance § 192.747 Valve maintenance: Distribution systems. (a) Each valve, the use of which may be necessary...

2012-10-01

361

Open cycle lithium chloride cooling system  

NASA Astrophysics Data System (ADS)

A lithium chloride open cycle absorption chiller has been designed, built and tested. Solution reconcentration takes place in a small counter current packed column supplied with solar heated air. Removal of noncondensable gases that enter the chiller dissolved in the strong solution and the make-up refrigerant streams is accomplished by a liquid-jet ejector and a small vacuum pump. Cooling capacities approaching 1.4 tons and COP levels of 0.58 have been achieved at non-optimum operating conditions. Test results from preliminary system operation suggest that mass transfer processes in both the packed column reconcentrator and the absorber are controlled by concentration gradients in the lithium chloride solution. Liquid phase controlled mass transfer dictates an operating strategy different from the previously assumed gas phase controlled process to obtain maximum rates of evaporation in the packed column. Determination of optimal operating conditions leading to decreased electrical power consumption and improved cooling capacity and coefficient of performance will require further analysis and testing.

Lenz, T. G.; Loef, G. O. G.; Iyer, R.; Wenger, J.

1983-05-01

362

Open MPI for Cray XE/XK Systems  

SciTech Connect

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

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

2012-01-01

363

The Production and Distribution of Knowledge through Open and Distance Learning  

Microsoft Academic Search

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

Stephen Fox

1989-01-01

364

Managing the Complexity of Large Free and Open Source Package-Based Software Distributions  

Microsoft Academic Search

The widespread adoption of Free and Open Source Soft- ware (FOSS) in many strategic contexts of the information technology society has drawn the attention on the issues re- garding how to handle the complexity of assembling and managing a huge number of (packaged) components in a consistent and effective way. FOSS distributions (and in particular GNU\\/Linux-based ones) have always provided

Fabio Mancinelli; Jaap Boender; Roberto Di Cosmo; Jerome Vouillon; Berke Durak; Xavier Leroy; Ralf Treinen

2006-01-01

365

Combination of Neural Network and SBFM Algorithm for Monitoring VOCs Distribution by Open Path FTIR Spectrometry  

Microsoft Academic Search

In this research, the combination of artificial neural network (ANN) modeling and smooth basis function minimization (SBFM) algorithm were applied to Open Path Fourier transform infrared spectroscopy (OP?FTIR) for monitoring volatile organic compounds' concentration distribution in the air. ANN was utilized to analyze the measured mixture spectra containing chloroform, methanol, and methylene chloride; Then, SBFM was used to reconstruct each

Yibo Ren; Yan Li; Baihua Yu; Junde Wang; Lanping Hu

2007-01-01

366

A Declarative Extension of IDL-based Type Definitions within Open Distributed Environments  

Microsoft Academic Search

An open distributed environment can be perceived as a service market where servicesare freely offered and requested. Any infrastructure which seeks to provide appropriatemechanisms for such an environment has to include some mediator functionalityto bring together matching service requests and service offers. The matching algorithmthat the mediator must perform commonly builds upon an IDL-based type definitionfor service specification. In order

Arno Puder

1994-01-01

367

Power Flow Analysis for Balanced and Unbalanced Radial Distribution Systems  

Microsoft Academic Search

This paper reports on an efficient method of power flow analysis for solving balanced and unbalanced radial distribution systems. The radial distribution system is modelled as a series of interconnected single feeders. Using Kirchoff's laws, a set of iterative power flow equations was developed to conduct the power flow studies. Due to the voltage dependency of loads in distribution systems,

H. M. Mok; S. Elangovan; M. M. A. Salama; Cao Longjian

368

Structural transformation of the Japanese retail distribution system  

Microsoft Academic Search

States that there is compelling evidence that the Japanese retail distribution system is changing. This study uses census data for ten years (1985 to 1994) to understand past changes in the structure of the retail distribution system. To understand the likely changes to the distribution system in the future, data were collected from 136 Japanese manufacturers and retailers. Results suggest

Ritu Lohtia; Ramesh Subramaniam

2000-01-01

369

Imposing Radiality Constraints in Distribution System Optimization Problems  

Microsoft Academic Search

Distribution systems commonly operate with a radial topology, so all models of optimization problems in these distribution systems should consider radiality in their formulation. This work presents a literature review, a critical analysis, and a proposal for incorporating the radiality constraints in mathematical models of optimization problems for radial distribution systems. The objective is to show that the radiality constraints

Marina Lavorato; John F. Franco; Marcos J. Rider; Rubén Romero

2012-01-01

370

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

371

Services Supporting Management of Distributed Applications and Systems  

Microsoft Academic Search

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

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

1997-01-01

372

Allocating modelling resources in distributed model management systems  

Microsoft Academic Search

Due to the growing popularity of distributed computing systems and the increased level of modelling activity in most organizations, significant benefits can be realized through the implementation of distributed model management systems (DMMS). These systems can be defined as a collection of logically related modelling resources distributed over a computer network. In several ways, functions of DMMS are isomorphic to

Ishwar Murthy; Deb Ghosh; Allen Moffett

1992-01-01

373

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

374

HPC: A Model of Structure and Change in Distributed Systems  

Microsoft Academic Search

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

Thomas J. Leblanc; Stuart A. Friedberg

1985-01-01

375

Multiple weapon system distributed sensor concept  

NASA Astrophysics Data System (ADS)

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

Rafailov, Michael K.

2009-05-01

376

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

377

Energy Efficiency of Distributed Environmental Control Systems  

SciTech Connect

In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control with a thermostat at each workstation. The thermal model shows that, un-optimized, DECS would lead to an increase in building energy consumption between 3-16% compared to the conventional approach depending on the climate regional and personal preferences of building occupants. Variations in building shape had little impact in the relative energy usage. 2. Development of a gradient-based optimization method to minimize energy consumption of DECS while keeping each occupant’s thermal dissatisfaction below a given threshold. The DECS energy usage was calculated using the simplified thermal model. OSFA control; providing a uniform temperature to the entire building, and occupant-selected HIYW control with a thermostat at each workstation were implemented for 3 cities representing 3 different climatic regions and control scenarios. It is shown that optimization allows DECS to deliver a higher level of individual and population thermal comfort while achieving annual energy savings between 14 and 26% compared to OSFA. The optimization model also allowed us to study the influence of the partitions’ thermal resistance and the variability of internal loads at each office. These influences didn’t make significant changes in the optimized energy consumption relative to OSFA. The results show that it is possible to provide thermal comfort for each occupant while saving energy compared to OSFA Furthermore, to simplify the implementation of this approach, a fuzzy logic system has been developed to generalize the overall optimization strategy. Its performance was almost as good as the gradient system. The fuzzy system provided thermal comfort to each occupant and saved energy compared to OSFA. The energy savings of the fuzzy system were not as high as for the gradient-optimized system, but the fuzzy system avoided complete connectivity, and the optimization did not have to be repeated for each population. 3. We employed a detailed CFD model of adjacent occupied cubicles to extend the thermal-circuit model in three significant ways: (a) relax the “office wall” requirement by allowing energy to flow between zones via advection as well as conduction, (b) improve the comfort model to account both for radiation as well as convection heat transfer, and (c) support ventilation systems in which the temperature is stratified, such as in underfloor air distribution systems. Initially, three-dimensional CFD simulations of several cubicle configurations, with an adjoining corridor, were performed both to understand the advection between cubicles and the

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

2011-02-23

378

openEyes: an open-hardware open-source system for low-cost eye tracking  

Microsoft Academic Search

Eye tracking has long held the promise of being a useful methodology for human computer interaction. However, a number of barriers have stood in the way of the integration of eye tracking into everyday applications, including the intrusiveness, robustness, availability and price of eye-tracking systems. To lower these barriers, we have developed the openEyes system. The system consists of an

Dongheng Li; Derrick J. Parkhurst

2006-01-01

379

A review of distributed power systems. Part II. High frequency AC distributed power systems  

Microsoft Academic Search

The present development state in high frequency (HF) AC distributed power systems (DPS) is reviewed. First, background and motivations of developing HF AC-DPS are addressed. Two types of basic HF AC-DPSs based on sine wave and square\\/PWM (pulsewidth modulated) wave bus are described, and the system level design considerations are discussed. Further, the issues and challenges in this research area

SHIGUO LUO; ISSA BATARSEH

2006-01-01

380

Open loop compensation in a stack-mass positioning system  

NASA Astrophysics Data System (ADS)

A piezoceramic stack-mass positioning system was tested with different frequencies and voltages for its response to different input conditions. It is observed that the response of the positioning system varied with different input conditions. A technique is developed to compensate for this variation by the use of an open loop compensator. This open loop controller is able to compensate for the phase lag inherent in the stack-mass system, thereby improving its dynamic response and position resolution.

Duong, Khanh; Garcia, Ephrahim

1995-03-01

381

Air distribution effectiveness and thermal stratification with stratified air distribution systems  

Microsoft Academic Search

Stratified air distribution systems such as Traditional Displacement Ventilation (TDV) and Under-Floor Air Distribution (UFAD) have been known to provide better indoor air quality. This thesis examined the influence of several key design parameters of TDV and UFAD in air distribution effectiveness and thermal stratification. ^ First, the literature concerning the ventilation performance of the TDV and UFAD systems was

Ki Sup Lee

2011-01-01

382

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

Microsoft Academic Search

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

U. Leeton; T. Ratniyomchai; T. Kulworawanichpong

2010-01-01

383

Fault Distribution Modeling Using Stochastic Bivariate Models for Prediction of Voltage Sag in Distribution Systems  

Microsoft Academic Search

This paper presents a new method regarding fault distribution modeling for the stochastic prediction study of voltage sags in the distribution system. 2-D stochastic models for fault modeling make it possible to obtain the fault performance for the whole system of interest, which helps to obtain not only sag performance at individual locations but also system sag performance through system

Bach Quoc Khanh; Dong-Jun Won; Seung-Il Moon

2008-01-01

384

Fault distribution modeling using stochastic bivariate models for prediction of voltage sag in distribution systems  

Microsoft Academic Search

This paper presents a new method on fault distribution modeling for stochastic prediction study of voltage sags in the distribution system. Two-dimensional stochastic models for fault modeling make it possible to obtain the fault performance for the whole system of interest, which helps obtaining not only sag performance at individual locations but also system sag performance through system indices of

Bach Quoc Khanh; Dong-Jun Won; Seung-II Moon

2008-01-01

385

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

NASA Astrophysics Data System (ADS)

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

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

2009-11-01

386

Open cycle ocean thermal energy conversion system  

SciTech Connect

An improved open cycle ocean thermal energy conversion system includes 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 flow path 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 flow path 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 there for and impart a desired flow direction to the steam. 10 figs.

Wittig, J.M.

1980-02-19

387

Open cycle ocean thermal energy conversion system  

SciTech Connect

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

388

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

389

Detection of contamination of municipal water distribution systems  

SciTech Connect

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

Cooper, John F. (Oakland, CA)

2012-01-17

390

Thermodynamic potentials in closed and open nanocrystalline systems: SiGe islands on Si(001)  

Microsoft Academic Search

The driving forces for alloying in Si-Ge epitaxial nanocrystalline islands were quantified experimentally. Closed and open systems were emulated by controlling surface diffusion kinetics [1]. Grazing Incidence X-Ray Diffraction (GIXRD) experiments were performed to map the composition and the strain distribution within the Si-Ge:Si(001) islands, permitting the evaluation of the relevant thermodynamic potentials for alloying. For the closed system the

Marina S. Leite; Angelo Malachias; Stefan W. Kycia; Ted I. Kamins; R. Stanley Williams; Gilberto Medeiros-Ribeiro

2008-01-01

391

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

392

An open operating system for a single-user machine  

Microsoft Academic Search

The file system and modularization of a single-user operating system are described. The main points of interest are the openness of the system, which establishes no sharp boundary between itself and the user's programs, and the techniques used to make the system robust.

Butler W. Lampson; Robert F. Sproull

1979-01-01

393

Personal Computers for Real-Time Control of Power System Distribution Networks  

Microsoft Academic Search

Personal computers offer a new way to design low-price, real-time supervisory control and data aquisition (SCADA) systems. The concept open up new areas of application by providing computerized control where it previously was unrealistic due to the cost. Computerized control of distribution level networks is thus possible. This paper analyzes the functional requirements of a SCADA-system, for realtime supervision and

Ulf Sandberg; Mats Faxer

1984-01-01

394

The Information System For Power Distribution System As Answer On New Demands In Power Distribution System  

Microsoft Academic Search

Information is most important thing now in 21st century. The many power utility company do not use information system for technical problems. This company work as before ten or fifty years. Only way for progress is insert information system into power utility system. Information system go into power utility company first as billing system. Next step is accounting, information system

S. M. Dragojlovic; O. T. Milenkovic; M. Vujicic

2005-01-01

395

Oxygen Enrichment for Open Cycle Magnetohydrodynamic Power Systems.  

National Technical Information Service (NTIS)

Efficient coal fired, open cycle MHD power generation systems require a combustion flame temperature of approximately 4600 F to provide adequate electrical conductivity in the MHD gas. To achieve this high flame temperature, either highly preheated combus...

1979-01-01

396

24. VIEW TO SOUTHWEST. DETAIL, GEAR TRAIN SYSTEM, BRIDGE OPEN ...  

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

24. VIEW TO SOUTHWEST. DETAIL, GEAR TRAIN SYSTEM, BRIDGE OPEN INDICATOR POINTER AT UPPER CENTER, CONTROL CABIN INFERIOR. - Gianella Bridge, Spanning Sacramento River at State Highway 32, Hamilton City, Glenn County, CA

397

16. VIEW NORTH FROM SWINGSPAN DECK, CHANNEL OPEN, FENDER SYSTEM ...  

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

16. VIEW NORTH FROM SWING-SPAN DECK, CHANNEL OPEN, FENDER SYSTEM AND ABUTMENT ON CHANNEL END OF NORTHERN FIXED SPAN; new bridge located on right - Tipers Bridge, Spanning Great Wicomico River at State Route 200, Kilmarnock, Lancaster County, VA

398

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

399

Research on multi-robot open architecture of an intelligent CNC system based on parameter-driven technology  

Microsoft Academic Search

This paper presents a multi-robot open architecture of an intelligent computer numerical control (CNC) system based on parameter-driven technology that has been developed for flexible and high-efficiency manipulation. An open architecture control system capable of distributed processing of decision-making and extraction of task information provides a premise for intelligent control and flexible operation. Intelligent detection with database feedback based on

Weike Song; Gang Wang; Juliang Xiao; Guodong Wang; Ying Hong

400

A model system for examining the radial distribution function  

Microsoft Academic Search

The radial distribution function provides a means of characterizing an amorphous material and is a measure of the spatial distribution of a system of particles. We introduce an experiment suitable for the undergraduate laboratory that illustrates the meaning and application of the radial distribution function to a two-dimensional system of hard spheres comprised of varying area fractions. Larger area fractions

K. Younge; C. Christenson; A. Bohara; J. Crnkovic; P. Saulnier

2004-01-01

401

Modeling and simulation of microturbine based distributed generation system  

Microsoft Academic Search

Distributed generation (DG) is predicted to play an important role in the electric power system in the near future. It is widely accepted that micro turbine-generation are currently attracting lot of attention to meet users' need in the distributed generation market. In order to investigate the ability of microturbine units in distribution systems, their efficient modeling is required. This paper

D. N. Gaonkar; R. N. Patel

2006-01-01

402

Impacts of Fault Diagnosis Schemes on Distribution System Reliability  

Microsoft Academic Search

Design and development of fault diagnosis schemes (FDS) for electric power distribution systems are major steps in realizing the self-healing function of a smart distribution grid. The application of the FDS in the electric power distribution systems is mainly aimed at precise detecting and locating of the deteriorated components, thereby enhancing the quality and reliability of the electric power delivered

Shahram Kazemi; Matti Lehtonen; Mahmud Fotuhi-Firuzabad

2012-01-01

403

Conceptualizing a shared language subsystem for distributed decision support systems  

Microsoft Academic Search

Researchers have only recently begun to develop formal architectures for support systems that capitalize on advancements in distributed technologies. Conceptual models have been proposed for distributed versions of both DSS and GDSS. To date, however, these developments have largely been limited to techniques employing shared global data spaces. Research on other approaches to distributed support systems development, including that based

Shawn D Bird

1997-01-01

404

Optimal fuzzy controller for voltage control in distribution systems  

Microsoft Academic Search

The increasing diffusion of distributed generation plants in recent years highlights problems concerning voltage regulation in medium voltage (MV) radial distribution networks. Among various possible control techniques able to regulate voltage profiles, intelligent systems based ones seems to be very promising. In particular, fuzzy control techniques are very interesting for a wide range of applicative fields like power distribution systems

Vito Calderaro; Vincenzo Galdi; Antonio Piccolo; Giovanni Massa

2011-01-01

405

Distribution system reliability: default data and model validation  

Microsoft Academic Search

Distribution system reliability assessment is able to predict the interruption profile of a distribution system based on system topology and component reliability data. Unfortunately, many utilities do not have enough historical component reliability data to perform such an assessment, and are not confident that other sources of data are representative of their particular system. As a result, these utilities do

R. E. Brown; J. R. Ochoa

1998-01-01

406

DC bus voltage control for a distributed power system  

Microsoft Academic Search

This paper addresses voltage control of distributed DC power systems. DC power systems have been discussed as a result of the introduction of renewable, small-scale power generation units. Also, telecommunication power systems featuring UPS properties might benefit from a broader introduction of DC power systems. Droop control is utilized to distribute the load between the source converters. In order to

P. Karlsson; J. Svensson

2003-01-01

407

DAISY: An Object-Oriented System for Distributed Artificial Intelligence  

Microsoft Academic Search

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

Agostino Poggi

1994-01-01

408

Wide area network performance study of a distribution management system  

Microsoft Academic Search

Moving towards a more competitive environment, distribution automation is considered a necessity for future power system operations. To include new automatic functions in a distribution management systems (DMS), loadings of the data links in the SCADA system will become very heavy. System upgrade or migration will need to be considered such that it can maintain a proper performance. To avoid

C. L. Su; C. N. Lu; M. C. Lin

1999-01-01

409

Agent-based modeling and simulation for open complex systems  

Microsoft Academic Search

Agent-based modeling and simulation (ABMS) offers a promising approach to deal with complexities of open complex systems. This article proposed an approach of agent-based modeling and simulation enhanced with pattern-oriented modeling strategy for open complex systems. An agent-based meta-model and its relevant model structure provided a unifying model basis of pattern-oriented agent-based modeling and simulation. This article implemented the agent-based

Guangjun Zhang; Yaodong Li

2010-01-01

410

An open-systems approach to video on demand  

Microsoft Academic Search

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

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

1994-01-01

411

ADSM -- An automated distribution system modeling tool for engineering analyses  

SciTech Connect

Designing and operating the distribution system efficiently and economically requires distribution engineers to perform various analytical studies frequently. The system models for these analyses are derived from the information residing in diverse utility databases. One major problem in utilizing these databases is the data mismatch due to different software specifications and hardware platforms. This means additional effort is required to transform data among these systems before engineers can perform any distribution system analyses. The Automated Distribution System Modeler (ADSM) developed jointly at the University of Washington (UW) and Puget Sound Power and Light Co. (PSPL) provides an automated approach for the distribution system modeling. This software tool builds a unified distribution system model automatically from the utility databases and provides a generic interface to various engineering analysis tools. This paper describes the Object-Oriented design concept of such a tool and discusses the merits of the Geographic Information System (GIS) environment used as a platform for ADSM.

Wei, X.G.; Venkata, S.S. [Univ. of Washington, Seattle, WA (United States). Electric Energy Group; Sumic, Z. [Univ. of Washington, Seattle, WA (United States). Electric Energy Group]|[Puget Sound Power and Light Co., Bellevue, WA (United States)

1995-02-01

412

Analysis of Stress and Strain Distribution in the Artery Wall Consisted of Layers with Different Elastic Modulus and Opening Angle  

NASA Astrophysics Data System (ADS)

Bovine thoracic aorta is stiffer in the inner wall than in the outer, and its opening angle is larger in the inner layer than in the outer. A model for mechanical analysis of such a heterogeneous artery wall was developed. The wall was assumed to be made of thin, incompressible, homogeneous, and isotropic layers having different elastic properties and opening angle. Stress and strain distributions in the wall were calculated using the opening angle and stress-strain relationship measured in thin sliced layers of bovine thoracic aortas. Stress distribution was uniform under a physiological condition if elastic properties and the opening angle were set uniform. Stress distribution was not uniform under any condition when the material heterogeneity was introduced. Such non-uniformity was reduced if heterogeneity in the opening angle was considered. The opening angle may be higher in the inner wall to compensate stress concentration caused by the material heterogeneity.

Matsumoto, Takeo; Sato, Masaaki

413

Fast Reconfiguration of Distribution Systems Considering Loss Minimization  

Microsoft Academic Search

This paper addresses the problem of finding the state of switching devices (open or closed) in primary distribution networks so that the total loss is minimum. Radiality and capacity constraints are taken into account. This optimization problem is a mixed-integer nonlinear optimization problem, in which the integer variables represent the state of the switches, and the continuous variables represent the

Hernán Prieto Schmidt; Nathan Ida; Nelson Kagan; João Carlos Guaraldo

2005-01-01

414

Geomorphic elements on modern distributive fluvial systems  

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

415

Distributed Fiber-Optic Intrusion Sensor System  

NASA Astrophysics Data System (ADS)

A distributed sensor system for detecting and locating intruders based on the phase-sensitive optical-time-domain reflectometer ( phi-OTDR) is described. The sensing element is a cabled single-mode telecommunications fiber buried along the monitored perimeter. Light pulses from a continuous-wave Er:fiber Fabry-Pérot laser with a narrow (approx 3 kHz) instantaneous linewidth and low (few kilohertz per second) frequency drift are injected into one end of the fiber, and the backscattered light is monitored with a photodetector. The effect of phase changes resulting from the pressure of the intruder on the ground immediately above the buried fiber are sensed by subtracting a phi-OTDR trace from an earlier stored trace. In laboratory tests with fiber on reels, the effects of localized phase perturbations induced by a piezoelectric fiber stretcher on phi-OTDR traces were observed. In field tests, people walking on the ground above a buried fiber cable induced phase shifts of several-pi radians.

Juarez, Juan C.; Maier, Eric W.; Choi, Kyoo Nam; Taylor, Henry F.

2005-06-01

416

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

417

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.

2011-01-01

418

Failure Model of a Distributed Transaction Processing System.  

National Technical Information Service (NTIS)

A general-purpose formal model of a distributed database system, including the necessary hardware, is developed, and its feasibility of implementation is shown with a practical example. The distributed programming environment is modelled as a set of objec...

K. Bjoern

1991-01-01

419

Open confinement systems and the D- sup 3 He reaction  

SciTech Connect

In this paper, the special synergisms between open-ended magnetic confinement systems and the D-{sup 3}He fuel cycle are discussed, both in general terms and through examples. Properties of open systems that make them especially suited for this fuel cycle include their ability to stably confine high-beta plasmas, their compatibility with electrostatic direct converters, and their linear geometry, which can greatly simplify the practical attainment of high magnetic fields. The example systems given include a linear collider and thermal barrier tandem mirror systems for both terrestrial and space travel applications. It is concluded that satisfying the demanding physics requirements posed by the D-{sup 3}He fuel cycle may be more readily possible through the use of open-ended magnetic systems than it will be through the use of closed systems of the tokamak genre.

Post, R.F. (Lawrence Livermore National Lab., CA (United States)); Santarius, J.F. (Wisconsin Univ., Madison, WI (United States). Food Research Inst.)

1992-08-01

420

The role of testing methodologies in open systems standards  

Microsoft Academic Search

This paper describes the lifecycle role of a conformance testing research facility in the open systems standards environment. This facility, the Clemson Automated Testing System (CATS), has demonstrated the value of integrating formalized test methods within all phases of standards development. IEEE's effort to develop a standard for operating systems interfaces (POSIX) has provided a working environment to investigate and

G. Deshmukh; R. Deshpande; J. Leathrum; K. Liburdy

1994-01-01

421

Entanglement generation and evolution in open quantum systems  

Microsoft Academic Search

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we study the continuous variable entanglement for a system consisting of two independent harmonic oscillators interacting with a general environment. We solve the Kossakowski-Lindblad master equation for the time evolution of the considered system and describe the entanglement in terms of the covariance matrix

Aurelian Isar

2009-01-01

422

Exploring Open Software System Acquisition Processes and Architectures  

Microsoft Academic Search

Abstract This study explores and develops concepts leading to the combination of best practices from open source software development (OSSD) projects with emerging capabilities for virtual system acquisition Virtual system acquisition is an evolving approach to demonstrate significant improvements in reducing the cost and cycle time for acquiring software - intensive systems, while improving their quality It employs techniques and

Walt Scacchi

423

Co-evaluation computation-based distributed intrusion detection system  

NASA Astrophysics Data System (ADS)

To improve detecting rates and reduce false detection of distributed network intrusion detection system, and to improve parallel processing ability of distributed intrusion detection system,co-evaluation computation-based distributed intrusion detection system is proposed. Optimized immune detecting method is used to reduce redundancy of detector. Multiagents evaluation computation is used to enhance self-learning ability and self-adaptation ability of network intrusion detection. Co-evaluation technology is used to speed co-evaluating of multi-agents in network intrusion detection system and then improve evaluating ability of distributed system. Experiments verify the validity of the method.

Su, Jie; Qiao, Peili; Li, Tao

2010-04-01

424

Optimal conductor selection for radial distribution systems  

Microsoft Academic Search

In this paper, an algorithm is proposed for selecting the optimum size of conductors of feeder sigments of radial distribution networks. The optimal size of conductor determined by load flow method is applied to the optimal distance radial distribution network. The conductor, which is determined by the proposed method, will maximize the total saving in cost of conducting material and

S Sivanagaraju; N Sreenivasulu; M Vijayakumar; T Ramana

2002-01-01

425

Evaluation System of Air Distribution in Gymnasium  

Microsoft Academic Search

Based on the characteristics and special function of gymnasiums, this thesis made a comprehensive assessment on mode selection of air distribution in gymnasiums by proposing that air distribution in gymnasiums be totally evaluated from the standpoints of degree of satisfaction in auditoriums and playing areas, improved air exchange efficiency and improved afterheat elimination efficiency. The thesis made a general conclusion

Ting Liao; Yon Ma; Junpeng Pang

2011-01-01

426

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...

427

Instantaneous magnetic field distribution in brushless permanent magnet DC motors. I. Open-circuit field  

Microsoft Academic Search

An analytical technique for predicting the instantaneous magnetic field distribution in the airgap region of radial-field topologies of brushless permanent-magnet DC motors, under any specified load condition and accounting implicitly for the stator winding current waveform and the effect of stator-slot-openings, has been developed. It is based on the superposition of the component fields due to the permanent magnet and

Z. Q. Zhu; David Howe; Ekkehard Bolte; Bemd Ackermann

1993-01-01

428

Constraints for the interconnection of distributed generation in radial distribution systems  

Microsoft Academic Search

After the recent introduction of the competitive electricity market in many countries, the number of small-size generators connected to the distribution systems is rapidly increasing. This paper analyses the impact of distributed generation (DG) on medium voltage (MV) distribution networks. In particular the modifications of voltage profiles, line currents and short circuit currents caused by the introduction of a synchronous

A. Agustoni; M. Brenna; R. Faranda; E. Tironi; C. Pincella; G. Simioli

2002-01-01

429

Investigating the Electric Power Distribution System (EPDS) Bus Voltage in the Presence of Distributed Generation (DG)  

Microsoft Academic Search

This paper investigates the Electric Power Distribution System (EPDS) bus voltage in the presence of Distributed Generation (DG). Distribution Company's (Discos) planner endeavor to develop new planning strategies for their network in order to serve the load growth and provide their customers with a reliable electric supply. In this research work, five different cases including preplanned islanding and grid-connected mode

Hasham Khan; Mohammad Ahmad Choudhry; Tahir Mahmood; Aamir Hanif

2006-01-01

430

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.

Burrell, Renita C.; Walters, John D.

2008-01-01

431

MODIST: Transparent Model Checking of Unmodified Distributed Systems  

Microsoft Academic Search

MODIST is the first model checker designed for transparently checking unmodified distributed systems running on unmod- ified operating systems. It achieves this transparency via a novel architecture: a thin interposition layer exposes all ac- tions in a distributed system and a centralized, OS-independent model checking engine explores these actions systematically. We made MODIST practical through three techniques: an ex- ecution

Junfeng Yang; Tisheng Chen; Ming Wu; Zhilei Xu; Xuezheng Liu; Haoxiang Lin; Mao Yang; Fan Long; Lintao Zhang; Lidong Zhou

2009-01-01

432

An Architecture for Real-Time Distributed Artificial Intelligent Systems  

Microsoft Academic Search

This paper introduces a new architecture for a real-time distributed artificial intelligence system: DENIS—a Dynamic Embedded Noticeboard Information System. The fundamental idea underlying the architecture draws heavily upon a distributed human system analogy, as seen, for example, in the workplace. The aim of DENIS is to provide a simple, meaningful means by which autonomous intelligent agents can cooperate and coordinate

J. Holt; M. G. Rodd

1994-01-01

433

A Wireless Distributed Wall Climbing Robotic System for Reconnaissance Purpose  

Microsoft Academic Search

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

Shanqiang Wu; Mantian Li; Shu Xiao; Yang Li

2006-01-01

434

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

435

Assessment of distributed photovoltaic electric-power systems. Final report  

Microsoft Academic Search

The purpose of this study was to develop a methodology for assessing the potential impacts of distributed photovoltaic (PV) systems on electric utility systems, including subtransmission and distribution networks, and to apply that methodology to several illustrative examples. The investigations focused upon five specific utilities. Three were actual planned future systems for Northeast Utilities Service Company, Alabama Power Company, and

R. W. Neal; P. F. DeDuck; R. N. Marshall

1982-01-01

436

Assessment of distributed photovoltaic electric-power systems. Summary report  

Microsoft Academic Search

The purpose of this study was to develop a methodology for assessing the potential impacts of distributed photovoltaic (PV) systems on electric utility systems, including subtransmission and distribution networks, and to apply that methodology to several illustrative examples. The investigations focused upon five specific utilities. Three were actual planned future systems for Northeast Utilities Service Company, Alabama Power Company, and

R. W. Neal; P. F. DeDuck; R. N. Marshall

1982-01-01

437

Service restoration of power distribution systems incorporating load curtailment  

Microsoft Academic Search

Power distribution systems are now integrating Smart Grid technologies allowing for widespread implementation of demand response and direct load control. This paper will present a service restoration problem formulation and solution algorithm for power distribution systems which incorporates load curtailment. A ranking based heuristic search algorithm is proposed which prioritizes the multi-objective service restoration problem and returns a new system

Michael Kleinberg; Karen Miu; Hsiao-Dong Chiang

2009-01-01

438

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

439

Planning optimal intelligent metering for distribution system monitoring and control  

Microsoft Academic Search

The accuracy of the distribution system state estimation is highly influenced by optimal meter allocation. This paper presents an innovative method for the placement optimization of power distribution system measurement. The goal of the method is to minimize the number of necessary measurements and required Remote Terminal Units, subject to the system observability requirements. The method based on particle swarm

L. Ramesh; S. P. Chowdhury; A. A. Natarajan

2008-01-01

440

Establishment of typical harmonic voltage levels in radial distribution systems  

Microsoft Academic Search

This paper reports on a simple method to identify problem areas with relation to harmonic distortion within radial distribution systems at the planning stage. The purpose of the work is to produce a simple method of establishing harmonic distortion levels throughout a study distribution system when only limited system data and load information is available. The preliminary work presented in

D. A. Robinson; V. J. Gosbell; B. S. P. Perera; D. J. Mannix

2000-01-01

441

PADS: A Policy Architecture for Building Distributed Storage Systems  

Microsoft Academic Search

This paper presents PADS, a new policy ar- chitecture that makes it easier to develop distributed stor- age systems. PADS is based on two key ideas. First, a distributed storage system is implemented by speci- fying a control plane that embodies the design policy of the system over a data plane that provides a set of common mechanisms. Second, the

Nalini Belaramani; Jiandan Zheng; Amol Nayate; Robert Soul; Mike Dahlin; Robert Grimm

442

PADS: A Policy Architecture for Distributed Storage Systems  

Microsoft Academic Search

This paper presents PADS ,a policy architecturefor build- ing distributed storage systems. A policy architecture has two aspects. First, a common set of mechanisms that al- low new systems to be implemented simply by defining new policies. Second, a structure for how policies, them- selves, should be specified. In the case of distributed storage systems, PADS defines a data plane

Nalini Moti Belaramani; Jiandan Zheng; Amol Nayate; Robert Soulé; Michael Dahlin; Robert Grimm

2009-01-01

443

Wide area network performance study of a distribution management system  

Microsoft Academic Search

Distribution automation is considered a necessity for providing better power service in a more competitive environment. When new automatic functions are included in a distribution management system (DMS), loadings of the data links in the supervisory control and data acquisition (SCADA) system will become very heavy. In order to maintain a proper performance, system upgrade or migration will need to

C.-L Su; C.-N Lu; M.-C Lin

2000-01-01

444

The electrical power distribution system for the nonelectrical engineer  

Microsoft Academic Search

An attempt is made to introduce to the nonelectrical engineer the basic components and terminologies associated with a power distribution system and to present the needs such a system requires to remain safe and reliable. Particular reference is made to the power distribution system of a cement plant

Robert A. Haas; M. J. Klova

1991-01-01

445

GEM: a generalized event monitoring language for distributed systems  

Microsoft Academic Search

Event-based monitoring is critical for managing and debugging networks and distributed systems. This paper presents GEM—an interpreted generalized event monitoring language. It allows high-level, abstract events to be specified in terms of combinations of lower-level events from different nodes in a loosely coupled distributed system. Event monitoring components can thus be distributed within the system to perform filtering, correlation and

Masoud Mansouri-Samani; Morris Sloman

1997-01-01

446

WiDS Checker: Combating Bugs in Distributed Systems  

Microsoft Academic Search

Despite many efforts, the predominant practice of debugging a distributed system is still printf-based log mining, which is both tedious and error-prone. In this paper, we present WiDS Checker, a unified framework that can check distributed systems through both simulation and reproduced runs from real deployment. All instances of a distributed system can be executed within one simulation process, multiplexed

Xuezheng Liu; Wei Lin; Aimin Pan; Zheng Zhang

2007-01-01

447

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

SciTech Connect

This paper presents a computer and communications system for controlling the operations of load management, distribution automation and distribution SCADA for a G and T cooperative, Old Dominion Electric Cooperative and its twelve member cooperatives. The system is currently being designed and delivered by a team of vendors, which involves an EMS/SCADA system vendor and a load management/distribution automation equipment vendor. The system coordinates the scheduling of load management for the member cooperatives so as to minimize the power bills to the power suppliers. Each member cooperative can use the system to implement distribution SCADA and distribution automation functions, thus improving its operation efficiency and service quality. This paper describes the functionalities, special features and the implementation and development experience for the system.

Chan, M.L. (ML Consulting Group, Sunnyvale, CA (US)); Crouch, W.H. Jr. (Old Dominion Electric Cooperative, Inc., Glen Allen, VA (US))

1990-01-01

448

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

449

Formation of Electron Distribution Function in ECR Discharge Sustained by Strong Microwave Emission in an Open Trap  

SciTech Connect

We consider a formation of Electron Distribution Function (EDF) in the Electron Cyclotron Resonance (ECR) discharge in an open trap. The ECR heating by strong microwaves, ionization, collisions and ambipolar losses are considered. The model is based on a system of two-dimensional Fokker-Plank equation for EDF. The stationary solution for EDF is investigated analytically. It consists of three groups of electrons: hot electrons with highly anisotropic velocity distribution that are heated in the ECR region, cold electrons with isotropic distribution that define the losses from the trap and warm electrons with considerably anisotropic distribution that are concentrated in the center of the trap and do not reach the ECR region. We build a qualitative model for the electron distribution function such that the original differential equation for EDF is transformed into two algebraic equations with two unknown parameters: neutral density and main plasma density. The latter can be solved analytically. The applicability of these results to a self-consistent model for ECR ion source is discussed. We show that the solution contradicts experimental results so that important effect is not taken into account in the model.

Erukhimov, V.L.; Semenov, V.E. [Institute of Applied Physics, RAS, Russia, 603950, Nizhny Novgorod, Ulyanova 46 (Russian Federation)

2005-03-15

450

Meeting the real-time synchronization requirements of multimedia in open distributed processing  

Microsoft Academic Search

D'stributed systems has been an area of 'nrense activity over the pasr ien years. The suo.ecr is entering a stage of maturity with word now focusing on standards for Open DisiribLred Processing (ODP). Recent y. nowever, a number of new cha lenges nave emerged for oistrio-red systems. Among these cha lenges, oisirib-red systems are 'ncreasingly having to support multimedia services,

Geoff Coulson; Gordon S. Blair

1994-01-01

451

Lightning-caused distribution transformer outages on a Florida distribution system  

Microsoft Academic Search

The data obtained from the research project on characteristics of lightning surges on distribution lines are presented. This project was conducted to measure the lightning-caused currents and voltages that occur on distribution lines and to quantify the distribution system damage that occurs because of lightning. During the 3-year data-gathering period, 2,448 distribution transformers were monitored. The estimated lightning-caused transformer failure

D. E. Parrish

1991-01-01

452

Task Allocation for Maximizing Reliability of Distributed Computer Systems  

Microsoft Academic Search

For distributed systems, system reliability is defined as the probability that the system can run an entire task successfully. When the system's hardware configuration is fixed, the system reliability is mainly dependent on the software design. The task allocation problem is addressed with the goal of maximizing the system reliability. A quantitative problem model, algorithms for optimal and suboptimal solutions,

Sol M. Shatz; Jia-ping Wang; Masanori Goto

1992-01-01

453

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

454

Current and Potential Distributions in Corrosion Systems.  

National Technical Information Service (NTIS)

Current and potential distribution calculations in corrosion are reviewed. The mathematical methods used, and the specific results for galvanic corrosion, cathodic protection, and localized corrosion are described. (ERA citation 05:038474)

W. H. Smyrl

1980-01-01

455

Foundations of Knowledge for Distributed Systems. Revision.  

National Technical Information Service (NTIS)

We give a simple, yet very general definition for distributed protocols. We then define notions of knowledge and common knowledge appropriate for these protocols. We study how changes in the states of knowledge relate to more standard notions of computati...

M. J. Fisher N. Immerman

1985-01-01

456

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...

457

STANDARDIZED COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS  

EPA Science Inventory

Presented within this report are cost data for construction and operation/maintenance of domestic water distribution and transmission pipelines, domestic water pumping stations, and domestic water storage reservoirs. ipeline cost data include costs for commonly utilized pipe mate...

458

Simplifying protection system design for distribution substations  

Microsoft Academic Search

Orion New Zealand Limited (Orion) is a distribution utility that serves the city of Christchurch, the second largest city in New Zealand. Orion is adopting the technical capabilities found in the IEC 61850 standard and other technologies for a simple-to-implement, fit-for-purpose design for distribution protection. Orion is successfully using protective relays that provide multiple zones of protection in one device,

Rich Hunt; John Coursey; Stephen Hirsch

2012-01-01

459

Open Access: How Is Scholarly Information Service System Going?  

NASA Astrophysics Data System (ADS)

Open access movement has resulted in a change of the entire scholarly communication environment. Scholarly information service system (SISS) had a significant change which is represented in the emergency of various open access publishing mode and diversification of integrated value-added service providers. This paper analyzed this change, and discussed how academic library should react to the change; also some possible impacts on scientific communication were discussed.

Xia, Nanqiang; Zhang, Yaokun

460

Distributed intrusion detection system based on grid security model  

NASA Astrophysics Data System (ADS)

Grid computing has developed rapidly with the development of network technology and it can solve the problem of large-scale complex computing by sharing large-scale computing resource. In grid environment, we can realize a distributed and load balance intrusion detection system. This paper first discusses the security mechanism in grid computing and the function of PKI/CA in the grid security system, then gives the application of grid computing character in the distributed intrusion detection system (IDS) based on Artificial Immune System. Finally, it gives a distributed intrusion detection system based on grid security system that can reduce the processing delay and assure the detection rates.

Su, Jie; Liu, Yahui

2008-03-01

461

Impact of customer scattering on distribution system reliability with distributed generation  

Microsoft Academic Search

This paper proposes the impact of customer scattering on reliability level of distribution system with distributed generation (DG). Variations of customer scattering are formed into six cases. Each customer scattering case is analyzed for finding the reliability indices of the system when there is no DG, and when DG unit is installed at various locations along the feeder. In addition,

N. Chaiyabut; P. Damrongkulkamjorn

2010-01-01

462

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

463

On Distributed Computing Systems Reliability Analysis Under Program Execution Constraints  

Microsoft Academic Search

Presents an algorithm for computing the reliability of distributed computing systems (DCS). The algorithm, called the Fast Reliability Evaluation Algorithm, is based on the factoring theorem employing several reliability preserving reduction techniques. The effect of file distributions, program distributions, and various topologies on reliability of the DCS is studied in detail using the proposed algorithm. Compared with existing algorithms on

Deng-jyi Chen; Min-sheng Lin

1994-01-01

464

Fast decoupled power flow for unbalanced radial distribution systems  

Microsoft Academic Search

This paper presents a novel power flow formulation and an effective solution method for general unbalanced radial distribution systems. Comprehensive models are considered including lines, switches, transformers, shunt capacitors, cogenerators, and several types of loads. A new problem formulation of three-phase distribution power flow equations taking into account the radial structure of the distribution network is presented. A distinguishing feature

Ray D. Zimmerman; Hsiao-Dong Chiang

1995-01-01

465

Probability distribution of channel holding time in cellular telephony systems  

Microsoft Academic Search

This paper investigates the channel holding time and call inter-arrival distributions in cellular telephony systems. Up until now, it has been generally assumed that both these distributions can be approximated by the negative exponential model. A study is presented which, using real cellular data, determines the actual distributions. It is shown that the negative exponential assumption for channel holding time

Chris Jedrzycki; V. C. M. Leung

1996-01-01

466

Driven harmonic oscillator as a quantum simulator for open systems  

SciTech Connect

We show theoretically how a driven harmonic oscillator can be used as a quantum simulator for the non-Markovian damped harmonic oscillator. In the general framework, our 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 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.

Piilo, Jyrki; Maniscalco, Sabrina [Department of Physics, University of Turku, FI-20014 Turun yliopisto (Finland)

2006-09-15

467

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

468

Optimization of open pit loading and hauling systems  

SciTech Connect

PITSIM-II is a computer simulation package that optimizes and simulates open pit haulage systems. The computer model was created in a generalized form that allows the analysis of any open pit loading and hauling system. The main objective of the model is to aid mine management in designing the haulage system and selecting the optimum combination of mixed size trucks. It is also a valuable tool in assisting the mine operator to operate the fleet in an optimum way, in order to meet certain production and blending targets. The other objectives of the model is to aid short and long range production scheduling in terms of forecasting the expected production rates.

Fytas, K.; Calder, P.N.

1984-12-01

469

Open-system electronic dynamics and thermalized electronic structure  

NASA Astrophysics Data System (ADS)

We propose and implement a novel computational method for simulating open-system electronic dynamics and obtaining thermalized electronic structures within an open quantum system framework. The system-bath interaction equation of motion is derived and modeled from the local harmonic oscillator description for electronic density change. The nonequilibrium electronic dynamics in a thermal bath is simulated using first-order kinetics. The resultant electronic densities are temperature-dependent and can take characteristics of the ground and excited states. We present results of calculations performed on H2 and 1,3-butadiene performed at the Hartree-Fock level of theory using a minimal Slater-type orbital basis set.

Chapman, Craig T.; Liang, Wenkel; Li, Xiaosong

2011-01-01

470

On-demand pressurized water distribution system impacts on sprinkler network design and performance  

Microsoft Academic Search

On-farm irrigation networks are designed for optimum performance at a specific upstream pressure head. In pressurized water\\u000a distribution systems operating on demand, the upstream pressure head of the on-farm network can be subject to high and continuous\\u000a fluctuations depending on the number of the hydrants being simultaneously opened. In this paper, a methodology combining network\\u000a design and performance analysis of

Andre Daccache; N. Lamaddalena; U. Fratino

2010-01-01

471

Massively Distributed Systems : From Grids and P2P to Clouds  

Microsoft Academic Search

This keynote describes the evolution of massively distributed computing systems and their key techniques. Clusters of computers\\u000a now prevail, expand, and become the core components in large-scale computational\\/ information\\/data Grids. The Open Grid Service\\u000a Architecture, specifying the Grid software, protocol, and service standards, are only partially implemented in Globus and\\u000a other Grid toolkits. Grid security demand globalization among various PKI

Kai Hwang

2008-01-01

472

Reinforcement Learning (RL) to Optimal Reconfiguration of Radial Distribution System (RDS)  

Microsoft Academic Search

\\u000a This paper presents a Reinforcement Learning (RL) method for optimal reconfiguration of radial distribution system (RDS).\\u000a Optimal reconfiguration involves selection of the best set of branches to be opened, one from each loop, such that the resulting\\u000a RDS has the desired performance. Among the several performance criteria considered for optimal network reconfiguration, an\\u000a important one is real power losses minimization,

John G. Vlachogiannis; Nikos D. Hatziargyriou

2004-01-01

473

Worst-Case Response Time Analysis for OSEK\\/VDX Compliant Real-Time Distributed Control Systems  

Microsoft Academic Search

Temporal behaviors prediction is very critical for real-time control systems. This paper presents a method to analyse the worst-case response time of OSEK\\/VDX compliant hard real-time distributed control systems. OSEK\\/VDX is an industry standard for an open-ended architecture for distributed control units in vehicles. Traditional time analysis methods based on the fixed priority preemptive scheduling model do not account for

Lei Wang; Zhaohui Wu; Mingde Zhao

2004-01-01

474

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

ERIC Educational Resources Information Center

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

Gleason, Bernard W.

475

Profitability under an Open versus a Closed System  

Microsoft Academic Search

This paper explores the conditions under which a monopolist selling a system consisting of a main component and differentiated secondary components can increase profits by allowing competition in the aftermarket for the secondary components. Opening the system in this fashion can increase profits by giving consumers an added incentive to incur the setup cost of purchasing the main component. This

Michael Kende

1998-01-01

476

Non-Hermitian Tunneling of Open Quantum Systems  

Microsoft Academic Search

We discuss some aspects of the time picture of tunneling for open quantum systems described by non-Hermitian (NH) Hamiltonians. The concept of sojourn time for such systems is introduced in the framework of the biorthonormal formalism. Due to the various definitions of probability density in the non-Hermitian case, we get three different sojourn times, two real and one complex. We

P. Angelopoulou; S. Baskoutas; A. Jannussis; R. Mignani; V. Papatheou

1995-01-01

477

Optimal Open-Loop Control of Stochastic Systems.  

National Technical Information Service (NTIS)

The problem of optimal open-loop control of stochastic systems is treated. The system is assumed to be modeled by a stochastic differential equation and the admissible controls are taken to be deterministic functions of time. The optimal control is the co...

J. D. Dillow

1969-01-01

478

Greenstone: a comprehensive open-source digital library software system  

Microsoft Academic Search

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

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

2000-01-01

479

Greenstone: A Comprehensive Open-Source Digital Library Software System  

Microsoft Academic Search

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

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

1999-01-01

480

OpenWLC: A Scalable Workload Characterization System  

Microsoft Academic Search

This paper discusses the design and development of a workload characterization system, known as OpenWLC, for large-scale computing systems. Large-scale hereafter implies computing systems with number of nodes ranging from thousands to hundreds of thousand. In such environment, it is critical to accurately monitor the system activities (workloads) and determine the potential performance bottlenecks that limit its effectiveness. Obviously, the

Hong Ong; Rajagopal Subramaniyan; Chokchai Leangsuksun; R. Scott Studham

481

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Distribution of shares by registered open-end...CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.12b-1...necessarily limited to, advertising, compensation of underwriters,...

2013-04-01

482

Mathematical Simulation of Power Conditioning Systems. Volume 4: Systems Simulation: Regulated Bus, AC Distribution, MPPT System Simulation Mathematique des Systemes de Conditionnement de Puissance. Simulation des Systemes. Barre Regulee, Distribution Alternative, Systeme Mppt.  

National Technical Information Service (NTIS)

Systems simulations are presented for the regulated bus concept, for the ac distribution system, and for the Maximum Power Point Tracking (MPPT) distribution system. Results show that the regulated bus system performs relatively well both for continuous a...

R. Prajoux J. Mazankine

1976-01-01

483

A Power Flow Method for Radial and Meshed Distribution Systems Including Distributed Generation and Step Voltage Regulator Modeling  

Microsoft Academic Search

This paper proposes a new power flow method for radial and meshed distribution systems. The method convert a meshed distribution system with distributed generators into an equivalent single source radial distribution system, by breaking out the tie lines and distributed generators con- nections, and by abstracting auxiliary buses to the distri- bution network. The approach goes beyond the previous works

Diego Issicaba; J. Coelho

2007-01-01

484

Network Reconfiguration for Service Restoration in Shipboard Power Distribution Systems  

Microsoft Academic Search

The electric power systems of U.S. Navy ships supply energy to sophisticated systems for weapons, communications, navigation, and operation. Circuit breakers (CBs) and fuses are provided at different locations for isolation of faulted loads, generators, or distribution system from unfaulted portions of the system. These faults could be due to widespread system fault resulting from battle damage or material casualties

K. L. Butler; N. D. R. Sarma; V. Ragendra Prasad

2001-01-01

485

Network reconfiguration for service restoration in shipboard power distribution systems  

Microsoft Academic Search

Summary form only given, as follows. The electric power systems of US Navy ships supply energy to sophisticated systems for weapons, communications, navigation and operation. Circuit breakers (CBs) and fuses are provided at different locations for isolation of faulted loads, generators or distribution system from unfaulted portions of the system. These faults could be due to widespread system faults resulting

K. L. Butler; N. D. R. Sarma; V. Ragendra Prasad

2002-01-01

486

Network reconfiguration for service restoration in shipboard power distribution systems  

Microsoft Academic Search

The electric power systems of US Navy ships supply energy to sophisticated systems for weapons, communications, navigation and operation. Circuit breakers (CBs) and fuses are provided at different locations for isolation of faulted loads, generators or distribution system from unfaulted portions of the system. These faults could be due to widespread system fault resulting from battle damage or material casualties

Karen L. Butler; N. D. R. Sarma; V. Ragendra Prasad

2001-01-01

487

Systems under Intelligent Distributed DoS Attacks  

Microsoft Academic Search

In the framework of a set of clients communicating with a critical server over the Internet, a recent approach to protect communication from Distributed Denial of Service (DDoS) attacks involves the usage of overlay systems. SOS, MAYDAY and I3 are such systems. The overlay system serves as an intermediate forwarding system between the clients and the server, where the systems

Xun Wang; Sriram Chellappan; Phillip Boyer; Dong Xuan

488

A distributed intelligent robot system based on microcomputers  

Microsoft Academic Search

An intelligent robot system based on a distributed microcomputer system with five microprocessors is described. The improvement and extension of each processor are performed to build a real-time, but inexpensive intelligent robot system. Main efforts focus on the implementation of the system, system information classification and exchange, and function modules in each CPU. Shared information is divided into data base,

Tao Hong; Kai Xia; Wenli Xu; Chongduan Chen; Lin Lu

1993-01-01

489

Using distributed OLTP technology in a high performance storage system.  

National Technical Information Service (NTIS)

The design of scaleable mass storage systems requires various system components to be distributed across multiple processors. Most of these processes maintain persistent database-type information (i.e., metadata) on the resources they are responsible for ...

T. W. Tyler D. S. Fisher

1995-01-01

490

Completion report harmonic analysis of electrical distribution systems.  

National Technical Information Service (NTIS)

Harmonic currents have increased dramatically in electrical distribution systems in the last few years due to the growth in non-linear loads found in most electronic devices. Because electrical systems have been designed for linear voltage and current wav...

L. M. Tolbert

1996-01-01

491

Solar System Formation and the Distribution of Volatile Species.  

National Technical Information Service (NTIS)

To understand how the solar system formed we must understand the compositional distribution of the current system. Volatile species are particularly important in that their stability as condensed phases is limited in temperature-pressure space, and hence ...

J. I. Lunine

1994-01-01

492

49 CFR 191.11 - Distribution system: Annual report.  

Code of Federal Regulations, 2012 CFR

... Distribution system: Annual report. 191.11 Section 191.11...OTHER GAS BY PIPELINE; ANNUAL REPORTS, INCIDENT REPORTS, AND SAFETY-RELATED CONDITION...report for that system on DOT Form PHMSA F 7100.1-1....

2012-10-01

493

49 CFR 191.11 - Distribution system: Annual report.  

Code of Federal Regulations, 2011 CFR

... Distribution system: Annual report. 191.11 Section 191.11...OTHER GAS BY PIPELINE; ANNUAL REPORTS, INCIDENT REPORTS, AND SAFETY-RELATED CONDITION...report for that system on DOT Form PHMSA F 7100.1-1....

2011-10-01

494

An Analysis of the U.S. Distribution System  

Microsoft Academic Search

This paper forms part of an OECD project which addressed the issue of the structure and change in the distribution systems of seven OECD countries.The paper begins with a conceptual framework describing the functions, market outcomes and economic implications of the distribution sector. Next, it gives an overview of the U.S. distribution system in the 1980s. In particular, it discusses

Roger R. Betancourt

1993-01-01

495

Distributed Manufacturing as co-evolutionary system  

Microsoft Academic Search

Research into Distributed Manufacturing – originally focusing on control of autonomous production cells – has embraced over time the challenges of research into industrial networks and more and more identical issues are pursued in both of these fields. Existing strands of research in networks often explore social-dynamic relationships and contractual aspects, thereby ignoring the underlying dynamics based on characteristic issues:

R. Dekkers

2009-01-01

496

Indexing Patterns within a Distributed System  

Microsoft Academic Search

This paper is concerning issues regarding the semantic indexing of resources in a peer to peer network. An important requirement is a good quality of the discovery, i.e. the selection of results very related to a specific request. Keys used for indexing and the corresponding urls of indexed resources are stored in a distributed hash table scattered among the different

C. Mouline; Cristian Lai

2010-01-01

497

Language and learning in distributed systems  

Microsoft Academic Search

This study begins with the observation that in the last thirty years the nature of work has changed, becoming increasingly focused on highly complex tasks that require cross disciplinary teams cooperating in a fully distributed performance. ^ The objective of the research is descriptive, and addresses two main questions. The first question is, Do jointly developed linguistic artifacts tend to

Michael Kevin McMahon

2004-01-01

498

Abstract Communication Model for Distributed Systems  

Microsoft Academic Search

Abstract, In some distributed and mobile communication models, a message disappears in one place and miraculously appears in another. In reality, of course, there are no miracles. A message goes from one network to another; it can be lost or corrupted in the process. Here, we present a realistic but high-level communication model where abstract communicators represent various nets and

Uwe Glässer; Yuri Gurevich; Margus Veanes

2004-01-01

499

AIRFLOW DISTRIBUTION IN EXHAUST VENTILATION SYSTEMS  

Microsoft Academic Search

The distribution of airflows converging at a junction can be estimated from the predicted pressures just upstream of the junction fitting. However, the total pressure approach requires iterative solutions at each junction, and the current implementation of the static pressure approach provides a poor fit to published empirical data. A model to predict pressures upstream of junctions is proposed and

Steven E. Guffey

1991-01-01

500

ESTIMATING COSTS FOR WATER SUPPLY DISTRIBUTION SYSTEMS  

EPA Science Inventory

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