Science.gov

Sample records for distribution

  1. Distributed processing; distributed functions?

    PubMed Central

    Fox, Peter T.; Friston, Karl J.

    2016-01-01

    After more than twenty years busily mapping the human brain, what have we learned from neuroimaging? This review (coda) considers this question from the point of view of structure–function relationships and the two cornerstones of functional neuroimaging; functional segregation and integration. Despite remarkable advances and insights into the brain’s functional architecture, the earliest and simplest challenge in human brain mapping remains unresolved: We do not have a principled way to map brain function onto its structure in a way that speaks directly to cognitive neuroscience. Having said this, there are distinct clues about how this might be done: First, there is a growing appreciation of the role of functional integration in the distributed nature of neuronal processing. Second, there is an emerging interest in data-driven cognitive ontologies, i.e., that are internally consistent with functional anatomy. We will focus this review on the growing momentum in the fields of functional connectivity and distributed brain responses and consider this in the light of meta-analyses that use very large data sets to disclose large-scale structure–function mappings in the human brain. PMID:22245638

  2. Distributed computing

    SciTech Connect

    Chambers, F.B.; Duce, D.A.; Jones, G.P.

    1984-01-01

    CONTENTS: The Dataflow Approach: Fundamentals of dataflow. Architecture and performance. Assembler level programming. High level dataflow programming. Declarative systems: Functional programming. Logic programming and prolog. The ''language first'' approach. Towards a successor to von Neumann. Loosely-coupled systems: Architectures. Communications. Distributed filestores. Mechanisms for distributed control. Distributed operating systems. Programming languages. Closely-coupled systems: Architecture. Programming languages. Run-time support. Development aids. Cyba-M. Polyproc. Modeling and verification: Using algebra for concurrency. Reasoning about concurrent systems. Each chapter includes references. Index.

  3. Distributed Intelligence.

    ERIC Educational Resources Information Center

    McLagan, Patricia A.

    2003-01-01

    Distributed intelligence occurs when people in an organization take responsibility for creating innovations, solving problems, and making decisions. Organizations that have it excel in their markets and the global environment. (Author/JOW)

  4. Distributed Leadership.

    ERIC Educational Resources Information Center

    Lashway, Larry

    2003-01-01

    School-reform efforts in recent years have stressed, and expanded, the leadership role of the principal. But in the view of many analysts, the task of transforming a school is too complex for one person to accomplish alone. Consequently, a new model of leadership is developing: distributed leadership. This Research Roundup summarizes five…

  5. Distributive Justice and Distributive Quality.

    ERIC Educational Resources Information Center

    Wexler, Jacqueline Grennan

    American higher education in this century has been almost schizophrenic in its development. As money and knowledge began to spread more distributively across the population, the population began to demand for its children a more equitable access into the world of the more privileged. Education and privilege were highly correlated. Greater access…

  6. Distributed Optimization

    NASA Technical Reports Server (NTRS)

    Macready, William; Wolpert, David

    2005-01-01

    We demonstrate a new framework for analyzing and controlling distributed systems, by solving constrained optimization problems with an algorithm based on that framework. The framework is ar. information-theoretic extension of conventional full-rationality game theory to allow bounded rational agents. The associated optimization algorithm is a game in which agents control the variables of the optimization problem. They do this by jointly minimizing a Lagrangian of (the probability distribution of) their joint state. The updating of the Lagrange parameters in that Lagrangian is a form of automated annealing, one that focuses the multi-agent system on the optimal pure strategy. We present computer experiments for the k-sat constraint satisfaction problem and for unconstrained minimization of NK functions.

  7. Distributed Saturation

    NASA Technical Reports Server (NTRS)

    Chung, Ming-Ying; Ciardo, Gianfranco; Siminiceanu, Radu I.

    2007-01-01

    The Saturation algorithm for symbolic state-space generation, has been a recent break-through in the exhaustive veri cation of complex systems, in particular globally-asyn- chronous/locally-synchronous systems. The algorithm uses a very compact Multiway Decision Diagram (MDD) encoding for states and the fastest symbolic exploration algo- rithm to date. The distributed version of Saturation uses the overall memory available on a network of workstations (NOW) to efficiently spread the memory load during the highly irregular exploration. A crucial factor in limiting the memory consumption during the symbolic state-space generation is the ability to perform garbage collection to free up the memory occupied by dead nodes. However, garbage collection over a NOW requires a nontrivial communication overhead. In addition, operation cache policies become critical while analyzing large-scale systems using the symbolic approach. In this technical report, we develop a garbage collection scheme and several operation cache policies to help on solving extremely complex systems. Experiments show that our schemes improve the performance of the original distributed implementation, SmArTNow, in terms of time and memory efficiency.

  8. Distributed visualization

    SciTech Connect

    Arnold, T.R.

    1991-12-31

    Within the last half decade or so, two technological evolutions have culminated in mature products of potentially great utility to computer simulation. One is the emergence of low-cost workstations with versatile graphics and substantial local CPU power. The other is the adoption of UNIX as a de facto ``standard`` operating system on at least some machines offered by virtually all vendors. It is now possible to perform transient simulations in which the number- crunching capability of a supercomputer is harnessed to allow both process control and graphical visualization on a workstation. Such a distributed computer system is described as it now exists: a large FORTRAN application on a CRAY communicates with the balance of the simulation on a SUN-3 or SUN-4 via remote procedure call (RPC) protocol. The hooks to the application and the graphics have been made very flexible. Piping of output from the CRAY to the SUN is nonselective, allowing the user to summon data and draw or plot at will. The ensemble of control, application, data handling, and graphics modules is loosely coupled, which further generalizes the utility of the software design.

  9. Distributed visualization

    SciTech Connect

    Arnold, T.R.

    1991-01-01

    Within the last half decade or so, two technological evolutions have culminated in mature products of potentially great utility to computer simulation. One is the emergence of low-cost workstations with versatile graphics and substantial local CPU power. The other is the adoption of UNIX as a de facto standard'' operating system on at least some machines offered by virtually all vendors. It is now possible to perform transient simulations in which the number- crunching capability of a supercomputer is harnessed to allow both process control and graphical visualization on a workstation. Such a distributed computer system is described as it now exists: a large FORTRAN application on a CRAY communicates with the balance of the simulation on a SUN-3 or SUN-4 via remote procedure call (RPC) protocol. The hooks to the application and the graphics have been made very flexible. Piping of output from the CRAY to the SUN is nonselective, allowing the user to summon data and draw or plot at will. The ensemble of control, application, data handling, and graphics modules is loosely coupled, which further generalizes the utility of the software design.

  10. Distributive Education. Physical Distribution. Instructor's Curriculum.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    This distributive education performance-based instructional unit is designed to help students understand the system of physical distribution and to act as an aid to guiding students in preparing for future careers in the transportation industry dealing with the retail, wholesale, and service occupations. (Physical distribution involves the moving…

  11. Annual Coal Distribution

    EIA Publications

    2016-01-01

    The Annual Coal Distribution Report (ACDR) provides detailed information on domestic coal distribution by origin state, destination state, consumer category, and method of transportation. Also provided is a summary of foreign coal distribution by coal-producing state. All data for the report year are final and this report supersedes all data in the quarterly distribution reports.

  12. STIS MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2013-10-01

    The performance of MAMA microchannel plates can be monitored using a MAMA fold distribution procedure. The fold distribution provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of change in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the STIS MAMA Fold Distribution, Proposal 13149, as Cycle 20.

  13. STIS MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2012-10-01

    The performance of MAMA microchannel plates can be monitored using a MAMA fold distribution procedure. The fold distribution provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of change in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the STIS MAMA Fold Distribution, Proposal 12778, as Cycle 19.

  14. Distributed Data Management and Distributed File Systems

    NASA Astrophysics Data System (ADS)

    Girone, Maria

    2015-12-01

    The LHC program has been successful in part due to the globally distributed computing resources used for collecting, serving, processing, and analyzing the large LHC datasets. The introduction of distributed computing early in the LHC program spawned the development of new technologies and techniques to synchronize information and data between physically separated computing centers. Two of the most challenges services are the distributed file systems and the distributed data management systems. In this paper I will discuss how we have evolved from local site services to more globally independent services in the areas of distributed file systems and data management and how these capabilities may continue to evolve into the future. I will address the design choices, the motivations, and the future evolution of the computing systems used for High Energy Physics.

  15. Exponentiated power Lindley distribution.

    PubMed

    Ashour, Samir K; Eltehiwy, Mahmoud A

    2015-11-01

    A new generalization of the Lindley distribution is recently proposed by Ghitany et al. [1], called as the power Lindley distribution. Another generalization of the Lindley distribution was introduced by Nadarajah et al. [2], named as the generalized Lindley distribution. This paper proposes a more generalization of the Lindley distribution which generalizes the two. We refer to this new generalization as the exponentiated power Lindley distribution. The new distribution is important since it contains as special sub-models some widely well-known distributions in addition to the above two models, such as the Lindley distribution among many others. It also provides more flexibility to analyze complex real data sets. We study some statistical properties for the new distribution. We discuss maximum likelihood estimation of the distribution parameters. Least square estimation is used to evaluate the parameters. Three algorithms are proposed for generating random data from the proposed distribution. An application of the model to a real data set is analyzed using the new distribution, which shows that the exponentiated power Lindley distribution can be used quite effectively in analyzing real lifetime data. PMID:26644927

  16. Exponentiated power Lindley distribution

    PubMed Central

    Ashour, Samir K.; Eltehiwy, Mahmoud A.

    2014-01-01

    A new generalization of the Lindley distribution is recently proposed by Ghitany et al. [1], called as the power Lindley distribution. Another generalization of the Lindley distribution was introduced by Nadarajah et al. [2], named as the generalized Lindley distribution. This paper proposes a more generalization of the Lindley distribution which generalizes the two. We refer to this new generalization as the exponentiated power Lindley distribution. The new distribution is important since it contains as special sub-models some widely well-known distributions in addition to the above two models, such as the Lindley distribution among many others. It also provides more flexibility to analyze complex real data sets. We study some statistical properties for the new distribution. We discuss maximum likelihood estimation of the distribution parameters. Least square estimation is used to evaluate the parameters. Three algorithms are proposed for generating random data from the proposed distribution. An application of the model to a real data set is analyzed using the new distribution, which shows that the exponentiated power Lindley distribution can be used quite effectively in analyzing real lifetime data. PMID:26644927

  17. Cumulative Poisson Distribution Program

    NASA Technical Reports Server (NTRS)

    Bowerman, Paul N.; Scheuer, Ernest M.; Nolty, Robert

    1990-01-01

    Overflow and underflow in sums prevented. Cumulative Poisson Distribution Program, CUMPOIS, one of two computer programs that make calculations involving cumulative Poisson distributions. Both programs, CUMPOIS (NPO-17714) and NEWTPOIS (NPO-17715), used independently of one another. CUMPOIS determines cumulative Poisson distribution, used to evaluate cumulative distribution function (cdf) for gamma distributions with integer shape parameters and cdf for X (sup2) distributions with even degrees of freedom. Used by statisticians and others concerned with probabilities of independent events occurring over specific units of time, area, or volume. Written in C.

  18. Doubly Distributed Transactions

    Energy Science and Technology Software Center (ESTSC)

    2014-08-25

    Doubly Distributed Transactions (D2T) offers a technique for managing operations from a set of parallel clients with a collection of distributed services. It detects and manages faults. Example code with a test harness is also provided

  19. Distributed Learning Metadata Standards

    ERIC Educational Resources Information Center

    McClelland, Marilyn

    2004-01-01

    Significant economies can be achieved in distributed learning systems architected with a focus on interoperability and reuse. The key building blocks of an efficient distributed learning architecture are the use of standards and XML technologies. The goal of plug and play capability among various components of a distributed learning system…

  20. Video Distribution Systems.

    ERIC Educational Resources Information Center

    Davoust, David

    1994-01-01

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

  1. Verification of LHS distributions.

    SciTech Connect

    Swiler, Laura Painton

    2006-04-01

    This document provides verification test results for normal, lognormal, and uniform distributions that are used in Sandia's Latin Hypercube Sampling (LHS) software. The purpose of this testing is to verify that the sample values being generated in LHS are distributed according to the desired distribution types. The testing of distribution correctness is done by examining summary statistics, graphical comparisons using quantile-quantile plots, and format statistical tests such as the Chisquare test, the Kolmogorov-Smirnov test, and the Anderson-Darling test. The overall results from the testing indicate that the generation of normal, lognormal, and uniform distributions in LHS is acceptable.

  2. FRIB cryogenic distribution system

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  3. Cubic-normal distribution

    NASA Astrophysics Data System (ADS)

    Peng, Gan Chew; Hin, Pooi Ah; Ho, C. K.

    2015-12-01

    The power-normal distribution given in Yeo and Johnson in year 2000 is a unimodal distribution with wide ranges of skewness and kurtosis. A shortcoming of the power-normal distribution is that the negative and positve parts of the underlying random variable have to be specified by two different expressions of the standard normal random variable. In this paper, we construct a new distribution, called the cubic-normal distribution, via a single polynomial expression in cubic root function. Apart from having the properties which are similar to those of the power-normal distribution, this cubic-normal distribution can be developed into a multivariate version which is more attractive from the theoretical and computational points of view.

  4. Bivariate extreme value distributions

    NASA Technical Reports Server (NTRS)

    Elshamy, M.

    1992-01-01

    In certain engineering applications, such as those occurring in the analyses of ascent structural loads for the Space Transportation System (STS), some of the load variables have a lower bound of zero. Thus, the need for practical models of bivariate extreme value probability distribution functions with lower limits was identified. We discuss the Gumbel models and present practical forms of bivariate extreme probability distributions of Weibull and Frechet types with two parameters. Bivariate extreme value probability distribution functions can be expressed in terms of the marginal extremel distributions and a 'dependence' function subject to certain analytical conditions. Properties of such bivariate extreme distributions, sums and differences of paired extremals, as well as the corresponding forms of conditional distributions, are discussed. Practical estimation techniques are also given.

  5. Distributed generation systems model

    SciTech Connect

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  6. Cooling water distribution system

    DOEpatents

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  7. Statistical distribution sampling

    NASA Technical Reports Server (NTRS)

    Johnson, E. S.

    1975-01-01

    Determining the distribution of statistics by sampling was investigated. Characteristic functions, the quadratic regression problem, and the differential equations for the characteristic functions are analyzed.

  8. Distribution of Chinese names

    NASA Astrophysics Data System (ADS)

    Huang, Ding-wei

    2013-03-01

    We present a statistical model for the distribution of Chinese names. Both family names and given names are studied on the same basis. With naive expectation, the distribution of family names can be very different from that of given names. One is affected mostly by genealogy, while the other can be dominated by cultural effects. However, we find that both distributions can be well described by the same model. Various scaling behaviors can be understood as a result of stochastic processes. The exponents of different power-law distributions are controlled by a single parameter. We also comment on the significance of full-name repetition in Chinese population.

  9. Smart distribution systems

    DOE PAGESBeta

    Jiang, Yazhou; Liu, Chen -Ching; Xu, Yin

    2016-04-19

    The increasing importance of system reliability and resilience is changing the way distribution systems are planned and operated. To achieve a distribution system self-healing against power outages, emerging technologies and devices, such as remote-controlled switches (RCSs) and smart meters, are being deployed. The higher level of automation is transforming traditional distribution systems into the smart distribution systems (SDSs) of the future. The availability of data and remote control capability in SDSs provides distribution operators with an opportunity to optimize system operation and control. In this paper, the development of SDSs and resulting benefits of enhanced system capabilities are discussed. Amore » comprehensive survey is conducted on the state-of-the-art applications of RCSs and smart meters in SDSs. Specifically, a new method, called Temporal Causal Diagram (TCD), is used to incorporate outage notifications from smart meters for enhanced outage management. To fully utilize the fast operation of RCSs, the spanning tree search algorithm is used to develop service restoration strategies. Optimal placement of RCSs and the resulting enhancement of system reliability are discussed. Distribution system resilience with respect to extreme events is presented. Furthermore, test cases are used to demonstrate the benefit of SDSs. Active management of distributed generators (DGs) is introduced. Future research in a smart distribution environment is proposed.« less

  10. Distribution and Marketing Syllabus.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The distributive education program for grades 7 to 12 is organized around three career education phases: the career education phase (grades 7-10), the distributive phase (grade 11), and the competency cluster phase (grade 12). The grade 11 syllabus provides a six-page introduction which covers scheduling, cooperative work experience, the school…

  11. Advanced Distribution Management System

    NASA Astrophysics Data System (ADS)

    Avazov, Artur R.; Sobinova, Liubov A.

    2016-02-01

    This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

  12. Software distribution using xnetlib

    SciTech Connect

    Dongarra, J.J. |; Rowan, T.H.; Wade, R.C.

    1993-06-01

    Xnetlib is a new tool for software distribution. Whereas its predecessor netlib uses e-mail as the user interface to its large collection of public-domain mathematical software, xnetlib uses an X Window interface and socket-based communication. Xnetlib makes it easy to search through a large distributed collection of software and to retrieve requested software in seconds.

  13. Univariate Probability Distributions

    ERIC Educational Resources Information Center

    Leemis, Lawrence M.; Luckett, Daniel J.; Powell, Austin G.; Vermeer, Peter E.

    2012-01-01

    We describe a web-based interactive graphic that can be used as a resource in introductory classes in mathematical statistics. This interactive graphic presents 76 common univariate distributions and gives details on (a) various features of the distribution such as the functional form of the probability density function and cumulative distribution…

  14. Groundwater and Distribution Workbook.

    ERIC Educational Resources Information Center

    Ekman, John E.

    Presented is a student manual designed for the Wisconsin Vocational, Technical and Adult Education Groundwater and Distribution Training Course. This program introduces waterworks operators-in-training to basic skills and knowledge required for the operation of a groundwater distribution waterworks facility. Arranged according to the general order…

  15. The Concept of Distribution

    ERIC Educational Resources Information Center

    Wild, Chris

    2006-01-01

    This paper is a personal exploration of where the ideas of "distribution" that we are trying to develop in students come from and are leading to, how they fit together, and where they are important and why. We need to have such considerations in the back of our minds when designing learning experiences. The notion of "distribution" as a lens…

  16. Electrical Distribution Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This program guide contains the standard electrical distribution curriculum for technical institutes in Georgia. The curriculum encompasses the minimum competencies required for entry-level workers in the electrical distribution field, and in job skills such as construction, maintenance, and repair of overhead and underground electrical…

  17. Metrics for Food Distribution.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in food distribution, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  18. 24 CFR 203.423 - Distribution of distributive shares.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Distribution of distributive shares... and Distributive Shares § 203.423 Distribution of distributive shares. (a) The Commissioner may provide for the distribution to the mortgagor of a share of the participating reserve account if...

  19. 24 CFR 203.423 - Distribution of distributive shares.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Distribution of distributive shares... and Distributive Shares § 203.423 Distribution of distributive shares. (a) The Commissioner may provide for the distribution to the mortgagor of a share of the participating reserve account if...

  20. Distributed Propulsion Vehicles

    NASA Technical Reports Server (NTRS)

    Kim, Hyun Dae

    2010-01-01

    Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. are enabling a high degree of integration of the airframe and propulsion system in aircraft design. The National Aeronautics and Space Administration (NASA) has been investigating a number of revolutionary distributed propulsion vehicle concepts to increase aircraft performance. The concept of distributed propulsion is to fully integrate a propulsion system within an airframe such that the aircraft takes full synergistic benefits of coupling of airframe aerodynamics and the propulsion thrust stream by distributing thrust using many propulsors on the airframe. Some of the concepts are based on the use of distributed jet flaps, distributed small multiple engines, gas-driven multi-fans, mechanically driven multifans, cross-flow fans, and electric fans driven by turboelectric generators. This paper describes some early concepts of the distributed propulsion vehicles and the current turboelectric distributed propulsion (TeDP) vehicle concepts being studied under the NASA s Subsonic Fixed Wing (SFW) Project to drastically reduce aircraft-related fuel burn, emissions, and noise by the year 2030 to 2035.

  1. Distributional Learning of Appearance

    PubMed Central

    Griffin, Lewis D.; Wahab, M. Husni; Newell, Andrew J.

    2013-01-01

    Opportunities for associationist learning of word meaning, where a word is heard or read contemperaneously with information being available on its meaning, are considered too infrequent to account for the rate of language acquisition in children. It has been suggested that additional learning could occur in a distributional mode, where information is gleaned from the distributional statistics (word co-occurrence etc.) of natural language. Such statistics are relevant to meaning because of the Distributional Principle that ‘words of similar meaning tend to occur in similar contexts’. Computational systems, such as Latent Semantic Analysis, have substantiated the viability of distributional learning of word meaning, by showing that semantic similarities between words can be accurately estimated from analysis of the distributional statistics of a natural language corpus. We consider whether appearance similarities can also be learnt in a distributional mode. As grounds for such a mode we advance the Appearance Hypothesis that ‘words with referents of similar appearance tend to occur in similar contexts’. We assess the viability of such learning by looking at the performance of a computer system that interpolates, on the basis of distributional and appearance similarity, from words that it has been explicitly taught the appearance of, in order to identify and name objects that it has not been taught about. Our experiment tests with a set of 660 simple concrete noun words. Appearance information on words is modelled using sets of images of examples of the word. Distributional similarity is computed from a standard natural language corpus. Our computation results support the viability of distributional learning of appearance. PMID:23460927

  2. Technologies for Distributed Defense

    SciTech Connect

    Seiders, Barbara AB; Rybka, Anthony J.

    2002-07-01

    For Americans, the nature of warfare changed on September 11, 2001. Our national security henceforth will require distributed defense. One extreme of distributed defense is represented by fully deployed military troops responding to a threat from a hostile nation state. At the other extreme is a country of "citizen soldiers," with families and communities securing their common defense through heightened awareness, engagement as good neighbors, and local support of and cooperation with local law enforcement, emergency and health care providers. Technologies - for information exploitation, biological agent detection, health care surveillance, and security - will be critical to ensuring success in distributed defense.

  3. Distributed analysis at LHCb

    NASA Astrophysics Data System (ADS)

    Williams, Mike; Egede, Ulrik; Paterson, Stuart; LHCb Collaboration

    2011-12-01

    The distributed analysis experience to date at LHCb has been positive: job success rates are high and wait times for high-priority jobs are low. LHCb users access the grid using the GANGA job-management package, while the LHCb virtual organization manages its resources using the DIRAC package. This clear division of labor has benefitted LHCb and its users greatly; it is a major reason why distributed analysis at LHCb has been so successful. The newly formed LHCb distributed analysis support team has also proved to be a success.

  4. Ticks: Geographic Distribution

    MedlinePlus

    ... Atlas. Download this map [PDF - 1 page] Lone star tick ( Amblyomma americanum ) Where found: Widely distributed in ... is distinguished by a white dot or “lone star” on her back. Lone star tick saliva can ...

  5. DOLIB: Distributed Object Library

    SciTech Connect

    D`Azevedo, E.F.; Romine, C.H.

    1994-10-01

    This report describes the use and implementation of DOLIB (Distributed Object Library), a library of routines that emulates global or virtual shared memory on Intel multiprocessor systems. Access to a distributed global array is through explicit calls to gather and scatter. Advantages of using DOLIB include: dynamic allocation and freeing of huge (gigabyte) distributed arrays, both C and FORTRAN callable interfaces, and the ability to mix shared-memory and message-passing programming models for ease of use and optimal performance. DOLIB is independent of language and compiler extensions and requires no special operating system support. DOLIB also supports automatic caching of read-only data for high performance. The virtual shared memory support provided in DOLIB is well suited for implementing Lagrangian particle tracking techniques. We have also used DOLIB to create DONIO (Distributed Object Network I/O Library), which obtains over a 10-fold improvement in disk I/O performance on the Intel Paragon.

  6. Estimating Bias Error Distributions

    NASA Technical Reports Server (NTRS)

    Liu, Tian-Shu; Finley, Tom D.

    2001-01-01

    This paper formulates the general methodology for estimating the bias error distribution of a device in a measuring domain from less accurate measurements when a minimal number of standard values (typically two values) are available. A new perspective is that the bias error distribution can be found as a solution of an intrinsic functional equation in a domain. Based on this theory, the scaling- and translation-based methods for determining the bias error distribution arc developed. These methods are virtually applicable to any device as long as the bias error distribution of the device can be sufficiently described by a power series (a polynomial) or a Fourier series in a domain. These methods have been validated through computational simulations and laboratory calibration experiments for a number of different devices.

  7. Polygamy of distributed entanglement

    NASA Astrophysics Data System (ADS)

    Buscemi, Francesco; Gour, Gilad; Kim, Jeong San

    2009-07-01

    While quantum entanglement is known to be monogamous (i.e., shared entanglement is restricted in multipartite settings), here we show that distributed entanglement (or the potential for entanglement) is by nature polygamous. By establishing the concept of one-way unlocalizable entanglement (UE) and investigating its properties, we provide a polygamy inequality of distributed entanglement in tripartite quantum systems of arbitrary dimension. We also provide a polygamy inequality in multiqubit systems and several trade-offs between UE and other correlation measures.

  8. Generic Distributed Simulation Architecture

    SciTech Connect

    Booker, C.P.

    1999-05-14

    A Generic Distributed Simulation Architecture is described that allows a simulation to be automatically distributed over a heterogeneous network of computers and executed with very little human direction. A prototype Framework is presented that implements the elements of the Architecture and demonstrates the feasibility of the concepts. It provides a basis for a future, improved Framework that will support legacy models. Because the Framework is implemented in Java, it may be installed on almost any modern computer system.

  9. Sparse distributed memory

    NASA Technical Reports Server (NTRS)

    Kanerva, Pentti

    1988-01-01

    Theoretical models of the human brain and proposed neural-network computers are developed analytically. Chapters are devoted to the mathematical foundations, background material from computer science, the theory of idealized neurons, neurons as address decoders, and the search of memory for the best match. Consideration is given to sparse memory, distributed storage, the storage and retrieval of sequences, the construction of distributed memory, and the organization of an autonomous learning system.

  10. Sparse distributed memory

    SciTech Connect

    Kanerva, P.

    1988-01-01

    Theoretical models of the human brain and proposed neural-network computers are developed analytically. Chapters are devoted to the mathematical foundations, background material from computer science, the theory of idealized neurons, neurons as address decoders, and the search of memory for the best match. Consideration is given to sparse memory, distributed storage, the storage and retrieval of sequences, the construction of distributed memory, and the organization of an autonomous learning system. 63 refs.

  11. Distribution system simulator

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    In a series of tests performed under the Department of Energy auspices, power line carrier propagation was observed to be anomalous under certain circumstances. To investigate the cause, a distribution system simulator was constructed. The simulator was a physical simulator that accurately represented the distribution system from below power frequency to above 50 kHz. Effects such as phase-to-phase coupling and skin effect were modeled. Construction details of the simulator, and experimental results from its use are presented.

  12. STIS MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2010-09-01

    The performance of MAMA microchannel plates can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the STIS MAMA Fold Analysis {11863} during Cycle 17.

  13. STIS MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2011-10-01

    The performance of MAMA microchannel plates can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the STIS MAMA Fold Analysis, Proposal 12416, as Cycle 18.

  14. Polygamy of distributed entanglement

    SciTech Connect

    Buscemi, Francesco; Gour, Gilad; Kim, Jeong San

    2009-07-15

    While quantum entanglement is known to be monogamous (i.e., shared entanglement is restricted in multipartite settings), here we show that distributed entanglement (or the potential for entanglement) is by nature polygamous. By establishing the concept of one-way unlocalizable entanglement (UE) and investigating its properties, we provide a polygamy inequality of distributed entanglement in tripartite quantum systems of arbitrary dimension. We also provide a polygamy inequality in multiqubit systems and several trade-offs between UE and other correlation measures.

  15. Distributed generation hits market

    SciTech Connect

    1997-10-01

    The pace at which vendors are developing and marketing gas turbines and reciprocating engines for small-scale applications may signal the widespread growth of distributed generation. Loosely defined to refer to applications in which power generation equipment is located close to end users who have near-term power capacity needs, distributed generation encompasses a broad range of technologies and load requirements. Disagreement is inevitable, but many industry observers associate distributed generation with applications anywhere from 25 kW to 25 MW. Ten years ago, distributed generation users only represented about 2% of the world market. Today, that figure has increased to about 4 or 5%, and probably could settle in the 20% range within a 3-to-5-year period, according to Michael Jones, San Diego, Calif.-based Solar Turbines Inc. power generation marketing manager. The US Energy Information Administration predicts about 175 GW of generation capacity will be added domestically by 2010. If 20% comes from smaller plants, distributed generation could account for about 35 GW. Even with more competition, it`s highly unlikely distributed generation will totally replace current market structures and central stations. Distributed generation may be best suited for making market inroads when and where central systems need upgrading, and should prove its worth when the system can`t handle peak demands. Typical applications include small reciprocating engine generators at remote customer sites or larger gas turbines to boost the grid. Additional market opportunities include standby capacity, peak shaving, power quality, cogeneration and capacity rental for immediate demand requirements. Integration of distributed generation systems--using gas-fueled engines, gas-fired combustion engines and fuel cells--can upgrade power quality for customers and reduce operating costs for electric utilities.

  16. Distribution of perfusion.

    PubMed

    Glenny, Robb; Robertson, H Thomas

    2011-01-01

    Local driving pressures and resistances within the pulmonary vascular tree determine the distribution of perfusion in the lung. Unlike other organs, these local determinants are significantly influenced by regional hydrostatic and alveolar pressures. Those effects on blood flow distribution are further magnified by the large vertical height of the human lung and the relatively low intravascular pressures in the pulmonary circulation. While the distribution of perfusion is largely due to passive determinants such as vascular geometry and hydrostatic pressures, active mechanisms such as vasoconstriction induced by local hypoxia can also redistribute blood flow. This chapter reviews the determinants of regional lung perfusion with a focus on vascular tree geometry, vertical gradients induced by gravity, the interactions between vascular and surrounding alveolar pressures, and hypoxic pulmonary vasoconstriction. While each of these determinants of perfusion distribution can be examined in isolation, the distribution of blood flow is dynamically determined and each component interacts with the others so that a change in one region of the lung influences the distribution of blood flow in other lung regions. PMID:23737171

  17. 24 CFR 213.278 - Distribution of distributive share.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Distribution of distributive share. 213.278 Section 213.278 Housing and Urban Development Regulations Relating to Housing and Urban... Management Housing Insurance and Distributive Shares § 213.278 Distribution of distributive share. When...

  18. 24 CFR 213.278 - Distribution of distributive share.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Distribution of distributive share. 213.278 Section 213.278 Housing and Urban Development Regulations Relating to Housing and Urban... Management Housing Insurance and Distributive Shares § 213.278 Distribution of distributive share. When...

  19. The isotopic distribution conundrum.

    PubMed

    Valkenborg, Dirk; Mertens, Inge; Lemière, Filip; Witters, Erwin; Burzykowski, Tomasz

    2012-01-01

    Although access to high-resolution mass spectrometry (MS), especially in the field of biomolecular MS, is becoming readily available due to recent advances in MS technology, the accompanied information on isotopic distribution in high-resolution spectra is not used at its full potential, mainly because of lack of knowledge and/or awareness. In this review, we give an insight into the practical problems related to calculating the isotopic distribution for large biomolecules, and present an overview of methods for the calculation of the isotopic distribution. We discuss the key events that triggered the development of various algorithms and explain the rationale of how and why the various isotopic-distribution calculations were performed. The review is focused around the developmental stages as briefly outlined below, starting with the first observation of an isotopic distribution. The observations of Beynon in the field of organic MS that chlorine appeared in a mass spectrum as two variants with odds 3:1 lie at the basis of the first wave of algorithms for the calculation of the isotopic distribution, based on the atomic composition of a molecule. From here on, we explain why more complex biomolecules such as peptides exhibit a highly complex isotope pattern when assayed by MS, and we discuss how combinatorial difficulties complicate the calculation of the isotopic distribution on computers. For this purpose, we highlight three methods, which were introduced in the 1980s. These are the stepwise procedure introduced by Kubinyi, the polynomial expansion from Brownawell and Fillippo, and the multinomial expansion from Yergey. The next development was instigated by Rockwood, who suggested to decompose the isotopic distribution in terms of their nucleon count instead of the exact mass. In this respect, we could claim that the term "aggregated" isotopic distribution is more appropriate. Due to the simplification of the isotopic distribution to its aggregated counterpart

  20. Vaginal drug distribution modeling.

    PubMed

    Katz, David F; Yuan, Andrew; Gao, Yajing

    2015-09-15

    This review presents and applies fundamental mass transport theory describing the diffusion and convection driven mass transport of drugs to the vaginal environment. It considers sources of variability in the predictions of the models. It illustrates use of model predictions of microbicide drug concentration distribution (pharmacokinetics) to gain insights about drug effectiveness in preventing HIV infection (pharmacodynamics). The modeling compares vaginal drug distributions after different gel dosage regimens, and it evaluates consequences of changes in gel viscosity due to aging. It compares vaginal mucosal concentration distributions of drugs delivered by gels vs. intravaginal rings. Finally, the modeling approach is used to compare vaginal drug distributions across species with differing vaginal dimensions. Deterministic models of drug mass transport into and throughout the vaginal environment can provide critical insights about the mechanisms and determinants of such transport. This knowledge, and the methodology that obtains it, can be applied and translated to multiple applications, involving the scientific underpinnings of vaginal drug distribution and the performance evaluation and design of products, and their dosage regimens, that achieve it. PMID:25933938

  1. Distributed replica dynamics

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Chill, Samuel T.; Henkelman, Graeme

    2015-11-01

    A distributed replica dynamics (DRD) method is proposed to calculate rare-event molecular dynamics using distributed computational resources. Similar to Voter's parallel replica dynamics (PRD) method, the dynamics of independent replicas of the system are calculated on different computational clients. In DRD, each replica runs molecular dynamics from an initial state for a fixed simulation time and then reports information about the trajectory back to the server. A simulation clock on the server accumulates the simulation time of each replica until one reports a transition to a new state. Subsequent calculations are initiated from within this new state and the process is repeated to follow the state-to-state evolution of the system. DRD is designed to work with asynchronous and distributed computing resources in which the clients may not be able to communicate with each other. Additionally, clients can be added or removed from the simulation at any point in the calculation. Even with heterogeneous computing clients, we prove that the DRD method reproduces the correct probability distribution of escape times. We also show this correspondence numerically; molecular dynamics simulations of Al(100) adatom diffusion using PRD and DRD give consistent exponential distributions of escape times. Finally, we discuss guidelines for choosing the optimal number of replicas and replica trajectory length for the DRD method.

  2. Distributed replica dynamics.

    PubMed

    Zhang, Liang; Chill, Samuel T; Henkelman, Graeme

    2015-11-01

    A distributed replica dynamics (DRD) method is proposed to calculate rare-event molecular dynamics using distributed computational resources. Similar to Voter's parallel replica dynamics (PRD) method, the dynamics of independent replicas of the system are calculated on different computational clients. In DRD, each replica runs molecular dynamics from an initial state for a fixed simulation time and then reports information about the trajectory back to the server. A simulation clock on the server accumulates the simulation time of each replica until one reports a transition to a new state. Subsequent calculations are initiated from within this new state and the process is repeated to follow the state-to-state evolution of the system. DRD is designed to work with asynchronous and distributed computing resources in which the clients may not be able to communicate with each other. Additionally, clients can be added or removed from the simulation at any point in the calculation. Even with heterogeneous computing clients, we prove that the DRD method reproduces the correct probability distribution of escape times. We also show this correspondence numerically; molecular dynamics simulations of Al(100) adatom diffusion using PRD and DRD give consistent exponential distributions of escape times. Finally, we discuss guidelines for choosing the optimal number of replicas and replica trajectory length for the DRD method. PMID:26547163

  3. Sparse distributed memory overview

    NASA Technical Reports Server (NTRS)

    Raugh, Mike

    1990-01-01

    The Sparse Distributed Memory (SDM) project is investigating the theory and applications of massively parallel computing architecture, called sparse distributed memory, that will support the storage and retrieval of sensory and motor patterns characteristic of autonomous systems. The immediate objectives of the project are centered in studies of the memory itself and in the use of the memory to solve problems in speech, vision, and robotics. Investigation of methods for encoding sensory data is an important part of the research. Examples of NASA missions that may benefit from this work are Space Station, planetary rovers, and solar exploration. Sparse distributed memory offers promising technology for systems that must learn through experience and be capable of adapting to new circumstances, and for operating any large complex system requiring automatic monitoring and control. Sparse distributed memory is a massively parallel architecture motivated by efforts to understand how the human brain works. Sparse distributed memory is an associative memory, able to retrieve information from cues that only partially match patterns stored in the memory. It is able to store long temporal sequences derived from the behavior of a complex system, such as progressive records of the system's sensory data and correlated records of the system's motor controls.

  4. Distributed Wind Market Applications

    SciTech Connect

    Forsyth, T.; Baring-Gould, I.

    2007-11-01

    Distributed wind energy systems provide clean, renewable power for on-site use and help relieve pressure on the power grid while providing jobs and contributing to energy security for homes, farms, schools, factories, private and public facilities, distribution utilities, and remote locations. America pioneered small wind technology in the 1920s, and it is the only renewable energy industry segment that the United States still dominates in technology, manufacturing, and world market share. The series of analyses covered by this report were conducted to assess some of the most likely ways that advanced wind turbines could be utilized apart from large, central station power systems. Each chapter represents a final report on specific market segments written by leading experts in this field. As such, this document does not speak with one voice but rather a compendium of different perspectives, which are documented from a variety of people in the U.S. distributed wind field.

  5. Distributed data transmitter

    DOEpatents

    Brown, Kenneth Dewayne; Dunson, David

    2006-08-08

    A distributed data transmitter (DTXR) which is an adaptive data communication microwave transmitter having a distributable architecture of modular components, and which incorporates both digital and microwave technology to provide substantial improvements in physical and operational flexibility. The DTXR has application in, for example, remote data acquisition involving the transmission of telemetry data across a wireless link, wherein the DTXR is integrated into and utilizes available space within a system (e.g., a flight vehicle). In a preferred embodiment, the DTXR broadly comprises a plurality of input interfaces; a data modulator; a power amplifier; and a power converter, all of which are modularly separate and distinct so as to be substantially independently physically distributable and positionable throughout the system wherever sufficient space is available.

  6. Distributed data transmitter

    DOEpatents

    Brown, Kenneth Dewayne; Dunson, David

    2008-06-03

    A distributed data transmitter (DTXR) which is an adaptive data communication microwave transmitter having a distributable architecture of modular components, and which incorporates both digital and microwave technology to provide substantial improvements in physical and operational flexibility. The DTXR has application in, for example, remote data acquisition involving the transmission of telemetry data across a wireless link, wherein the DTXR is integrated into and utilizes available space within a system (e.g., a flight vehicle). In a preferred embodiment, the DTXR broadly comprises a plurality of input interfaces; a data modulator; a power amplifier; and a power converter, all of which are modularly separate and distinct so as to be substantially independently physically distributable and positionable throughout the system wherever sufficient space is available.

  7. On exchangeable multinomial distributions

    PubMed Central

    George, E. Olusegun; Cheon, Kyeongmi; Yuan, Yilian; Szabo, Aniko

    2016-01-01

    We derive an expression for the joint distribution of exchangeable multinomial random variables, which generalizes the multinomial distribution based on independent trials while retaining some of its important properties. Unlike de Finneti's representation theorem for a binary sequence, the exchangeable multinomial distribution derived here does not require that the finite set of random variables under consideration be a subset of an infinite sequence. Using expressions for higher moments and correlations, we show that the covariance matrix for exchangeable multinomial data has a different form from that usually assumed in the literature, and we analyse data from developmental toxicology studies. The proposed analyses have been implemented in R and are available on CRAN in the CorrBin package.

  8. Partonic Transverse Momentum Distributions

    SciTech Connect

    Rossi, Patrizia

    2010-08-04

    In recent years parton distributions have been generalized to account also for transverse degrees of freedom and new sets of more general distributions, Transverse Momentum Dependent (TMD) parton distributions and fragmentation functions were introduced. Different experiments worldwide (HERMES, COMPASS, CLAS, JLab-Hall A) have measurements of TMDs in semi-inclusive DIS processes as one of their main focuses of research. TMD studies are also an important part of the present and future Drell-Yan experiments at RICH and JPARC and GSI, respectively, Studies of TMDs are also one of the main driving forces of the Jefferson Lab (JLab) 12 GeV upgrade project. Progress in phenomenology and theory is flourishing as well. In this talk an overview of the latest developments in studies of TMDs will be given and newly released results, ongoing activities, as well as planned near term and future measurements will be discussed.

  9. Mars elevation distribution

    NASA Technical Reports Server (NTRS)

    Wu, Sherman S. C.; Howington-Kraus, Annie E.; Ablin, Karyn K.

    1991-01-01

    A Digital Terrain Model (DTM) of Mars was derived with both Mercator and Sinusoidal Equal-Area projections from the global topographic map of Mars (scale 1:15 million, contour interval 1 km). Elevations on the map are referred to Mars' topographic datum that is defined by the gravity field at a 6.1-millibar pressure surface with respect to the center of mass of Mars. The DTM has a resolution at the equator of 1/59.226 degrees (exactly 1 km) per pixel. By using the DTM, the volumetric distribution of Mars topography above and below the datum has previously been calculated. Three types of elevation distributions of Mars' topography were calculated from the same DTM: (1) the frequency distribution of elevations at the pixel resolution; (2) average elevations in increments of 6 degrees in both longitude and latitude; and (3) average elevations in 36 separate blocks, each covering 30 degrees of latitude and 60 degrees of longitude.

  10. Discrete Pearson distributions

    SciTech Connect

    Bowman, K.O.; Shenton, L.R.; Kastenbaum, M.A.

    1991-11-01

    These distributions are generated by a first order recursive scheme which equates the ratio of successive probabilities to the ratio of two corresponding quadratics. The use of a linearized form of this model will produce equations in the unknowns matched by an appropriate set of moments (assumed to exist). Given the moments we may find valid solutions. These are two cases; (1) distributions defined on the non-negative integers (finite or infinite) and (2) distributions defined on negative integers as well. For (1), given the first four moments, it is possible to set this up as equations of finite or infinite degree in the probability of a zero occurrence, the sth component being a product of s ratios of linear forms in this probability in general. For (2) the equation for the zero probability is purely linear but may involve slowly converging series; here a particular case is the discrete normal. Regions of validity are being studied. 11 refs.

  11. High voltage distributed amplifier

    NASA Astrophysics Data System (ADS)

    Willems, D.; Bahl, I.; Wirsing, K.

    1991-12-01

    A high-voltage distributed amplifier implemented in GaAs MMIC technology has demonstrated good circuit performance over at least two octave bandwidth. This technique allows for very broadband amplifier operation with good efficiency in satellite, active-aperture radar, and battery-powered systems. Also, by increasing the number of FETs, the amplifier can be designed to match different voltage rails. The circuit does require a small amount of additional chip size over conventional distributed amplifiers but does not require power dividers or additional matching networks. This circuit configuration should find great use in broadband power amplifier design.

  12. Distributed Sensors Simulator

    SciTech Connect

    Brennan, Sean M.

    2003-08-30

    The Distributed Sensors Simulator (DSS) is an infrastructure that allows the user to debug and test software for distributed sensor networks without the commitment inherent in using hardware. The flexibility of DSS allows developers and researchers to investigate topological, phenomenological, networking, robustness, and scaling issues; explore arbitrary algorithms for DSNs; and is particularly useful as a proof-of-concept tool. The user provides data on node location and specifications, defines event phenomena, and plugs in the application(s) to run. DSS in turn provides the virtual environmental embedding — but exposed to the user like no true embedding could ever be.

  13. A distributed Tier-1

    NASA Astrophysics Data System (ADS)

    Fischer, L.; Grønager, M.; Kleist, J.; Smirnova, O.

    2008-07-01

    The Tier-1 facility operated by the Nordic DataGrid Facility (NDGF) differs significantly from other Tier-1s in several aspects: firstly, it is not located at one or a few premises, but instead is distributed throughout the Nordic countries; secondly, it is not under the governance of a single organization but instead is a meta-center built of resources under the control of a number of different national organizations. We present some technical implications of these aspects as well as the high-level design of this distributed Tier-1. The focus will be on computing services, storage and monitoring.

  14. Input distributions for VISA

    SciTech Connect

    Liebetrau, A.M.

    1983-10-01

    Work is underway at Pacific Northwest Laboratory (PNL) to improve the probabilistic analysis used to model pressurized thermal shock (PTS) incidents in reactor pressure vessels, and, further, to incorporate these improvements into the existing Vessel Integrity Simulation Analysis (VISA) code. Two topics related to work on input distributions in VISA are discussed in this paper. The first involves the treatment of flaw size distributions and the second concerns errors in the parameters in the (Guthrie) equation which is used to compute ..delta..RT/sub NDT/, the shift in reference temperature for nil ductility transition.

  15. Distributed Sensors Simulator

    Energy Science and Technology Software Center (ESTSC)

    2003-08-30

    The Distributed Sensors Simulator (DSS) is an infrastructure that allows the user to debug and test software for distributed sensor networks without the commitment inherent in using hardware. The flexibility of DSS allows developers and researchers to investigate topological, phenomenological, networking, robustness, and scaling issues; explore arbitrary algorithms for DSNs; and is particularly useful as a proof-of-concept tool. The user provides data on node location and specifications, defines event phenomena, and plugs in the application(s)more » to run. DSS in turn provides the virtual environmental embedding — but exposed to the user like no true embedding could ever be.« less

  16. THERMAL DISTRIBUTION SYSTEM EXPERIMENT

    SciTech Connect

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

    1999-09-01

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

  17. Galactic distribution of pulsars

    NASA Technical Reports Server (NTRS)

    Seiradakis, J. H.

    1977-01-01

    The density distributions of pulsars in luminosity, period, Z-distance, and galactocentric distance were derived, using a uniform sample of pulsars detected during a 408-MHz pulsar survey at Jodrell Bank. There are indications of a fine-scale structure in the spatial distributions and evidence that there is a general correlation with other galactic populations and the overall spiral structure. The electron layer in our galaxy is shown to be wider than the pulsar layer and uniform on a large scale. The number of pulsars in the galaxy has been estimated and used to derive the pulsar birthrate.

  18. Galactic distribution of pulsars

    NASA Technical Reports Server (NTRS)

    Seiradakis, J. H.

    1976-01-01

    The density distributions of pulsars in luminosity, period, Z-distance, and galactocentric distance were derived using a uniform sample of pulsars detected during a 408 MHz pulsar survey at Jodrell Bank. There are indications of a fine scale structure in the spatial distribution and evidence that there is a general correlation with other galactic populations and the overall spiral structure. The electron layer in the galaxy is shown to be wider than the pulsar layer and uniform on a large scale. The number of pulsars in the galaxy was estimated and used to derive the pulsar birthrate.

  19. Program for standard statistical distributions

    NASA Technical Reports Server (NTRS)

    Falls, L. W.

    1972-01-01

    Development of procedure to describe frequency distributions involved in statistical theory is discussed. Representation of frequency distributions by first order differential equation is presented. Classification of various types of distributions based on Pearson parameters is analyzed.

  20. Distributed Continuous Registration.

    ERIC Educational Resources Information Center

    Myers, Donald L.

    1981-01-01

    The development, implementation, and features of Northern Colorado's continuous registration system are described. The system is an online distributed processing system, written in COBOL for an IBM Series I under the CPS operating system. Course selection, permit to enroll, and drop/add forms are provided. (Author/MLW)

  1. Enabling distributed petascale science.

    SciTech Connect

    Baranovski, A.; Bharathi, S.; Bresnahan, J.; chervenak, A.; Foster, I.; Fraser, D.; Freeman, T.; Gunter, D.; Jackson, K.; Keahey, K.; Kesselman, C.; Konerding, D. E.; Leroy, N.; Link, M.; Livny, M.; Miller, N.; Miller, R.; Oleynik, G.; Pearlman, L.; Schopf, J. M.; Schuler, R.; Tierney, B.; Mathematics and Computer Science; FNL; Univ. of Southern California; Univ. of Chicago; LBNL; Univ. of Wisconsin

    2007-01-01

    Petascale science is an end-to-end endeavour, involving not only the creation of massive datasets at supercomputers or experimental facilities, but the subsequent analysis of that data by a user community that may be distributed across many laboratories and universities. The new SciDAC Center for Enabling Distributed Petascale Science (CEDPS) is developing tools to support this end-to-end process. These tools include data placement services for the reliable, high-performance, secure, and policy-driven placement of data within a distributed science environment; tools and techniques for the construction, operation, and provisioning of scalable science services; and tools for the detection and diagnosis of failures in end-to-end data placement and distributed application hosting configurations. In each area, we build on a strong base of existing technology and have made useful progress in the first year of the project. For example, we have recently achieved order-of-magnitude improvements in transfer times (for lots of small files) and implemented asynchronous data staging capabilities; demonstrated dynamic deployment of complex application stacks for the STAR experiment; and designed and deployed end-to-end troubleshooting services. We look forward to working with SciDAC application and technology projects to realize the promise of petascale science.

  2. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  3. Distribution of Childrearing Demands.

    ERIC Educational Resources Information Center

    Zimmerman, Judith D.; And Others

    The tools of economic analysis were applied to demographic data in order to develop a social indicator measuring the extent of inequality in the distribution of childrearing responsibility in households from 1940 to 1980. With data drawn from the Current Population Survey of the Bureau of the Census, a "demand intensity" measure was developed.…

  4. Age Distribution of Groundwater

    NASA Astrophysics Data System (ADS)

    Morgenstern, U.; Daughney, C. J.

    2012-04-01

    Groundwater at the discharge point comprises a mixture of water from different flow lines with different travel time and therefore has no discrete age but an age distribution. The age distribution can be assessed by measuring how a pulse shaped tracer moves through the groundwater system. Detection of the time delay and the dispersion of the peak in the groundwater compared to the tracer input reveals the mean residence time and the mixing parameter. Tritium from nuclear weapons testing in the early 1960s resulted in a peak-shaped tritium input to the whole hydrologic system on earth. Tritium is the ideal tracer for groundwater because it is an isotope of hydrogen and therefore is part of the water molecule. Tritium time series data that encompass the passage of the bomb tritium pulse through the groundwater system in all common hydrogeologic situations in New Zealand demonstrate a semi-systematic pattern between age distribution parameters and hydrologic situation. The data in general indicate high fraction of mixing, but in some cases also indicate high piston flow. We will show that still, 45 years after the peak of the bomb tritium, it is possible to assess accurately the parameters of age distributions by measuring the tail of the bomb tritium.

  5. Distributive Education. Selling. Curriculum.

    ERIC Educational Resources Information Center

    Lankford, Dave; Comte, Don

    Nineteen lesson plans on selling are presented in this performance-based curriculum unit for distributive education. This unit is self-contained and consists of the following components: introduction (provides overview of unit content and describes why mastery of the objectives is important); performance objectives; pre-assessment instrument…

  6. Prototyping distributed simulation networks

    NASA Technical Reports Server (NTRS)

    Doubleday, Dennis L.

    1990-01-01

    Durra is a declarative language designed to support application-level programming. The use of Durra is illustrated to describe a simple distributed application: a simulation of a collection of networked vehicle simulators. It is shown how the language is used to describe the application, its components and structure, and how the runtime executive provides for the execution of the application.

  7. Distributed analysis in ATLAS

    NASA Astrophysics Data System (ADS)

    Dewhurst, A.; Legger, F.

    2015-12-01

    The ATLAS experiment accumulated more than 140 PB of data during the first run of the Large Hadron Collider (LHC) at CERN. The analysis of such an amount of data is a challenging task for the distributed physics community. The Distributed Analysis (DA) system of the ATLAS experiment is an established and stable component of the ATLAS distributed computing operations. About half a million user jobs are running daily on DA resources, submitted by more than 1500 ATLAS physicists. The reliability of the DA system during the first run of the LHC and the following shutdown period has been high thanks to the continuous automatic validation of the distributed analysis sites and the user support provided by a dedicated team of expert shifters. During the LHC shutdown, the ATLAS computing model has undergone several changes to improve the analysis workflows, including the re-design of the production system, a new analysis data format and event model, and the development of common reduction and analysis frameworks. We report on the impact such changes have on the DA infrastructure, describe the new DA components, and include recent performance measurements.

  8. Schooling and Income Distribution

    ERIC Educational Resources Information Center

    Marin, Alan; Psacharopoulos, George

    1976-01-01

    Analyzes the relationship between years of schooling and income distribution, based on human capital theory. (Available from North-Holland Publishing Company, P.O. Box 211, Amsterdam, the Netherlands; $13.50 annually, plus $4.00 postage and handling) (JG)

  9. Industrial power distribution

    SciTech Connect

    Sorrells, M.A.

    1990-01-01

    This paper is a broad overview of industrial power distribution. Primary focus will be on selection of the various low voltage components to achieve the end product. Emphasis will be on the use of national standards to ensure a safe and well designed installation.

  10. Distributed Information Management.

    ERIC Educational Resources Information Center

    Pottenger, William M.; Callahan, Miranda R.; Padgett, Michael A.

    2001-01-01

    Reviews the scope and effects of distributed information management. Discusses cultural and social influences, including library and Internet culture, information and knowledge, electronic libraries, and social aspects of libraries; digital collections; indexing; permanent link systems; metadata; the Open Archives initiative; digital object…

  11. Small School Distributive Education.

    ERIC Educational Resources Information Center

    Barnes, Bill

    Information on an atypical 1966-67 Distributive Education pilot program in New Mexico was given. The program was unique since one instructor conducted this program in two schools which were in separate rural districts (Dexter and Hagerman). Since both communities were primarily agricultural, with small student populations, the cost of such a…

  12. Multiagent distributed watershed management

    NASA Astrophysics Data System (ADS)

    Giuliani, M.; Castelletti, A.; Amigoni, F.; Cai, X.

    2012-04-01

    Deregulation and democratization of water along with increasing environmental awareness are challenging integrated water resources planning and management worldwide. The traditional centralized approach to water management, as described in much of water resources literature, is often unfeasible in most of the modern social and institutional contexts. Thus it should be reconsidered from a more realistic and distributed perspective, in order to account for the presence of multiple and often independent Decision Makers (DMs) and many conflicting stakeholders. Game theory based approaches are often used to study these situations of conflict (Madani, 2010), but they are limited to a descriptive perspective. Multiagent systems (see Wooldridge, 2009), instead, seem to be a more suitable paradigm because they naturally allow to represent a set of self-interested agents (DMs and/or stakeholders) acting in a distributed decision process at the agent level, resulting in a promising compromise alternative between the ideal centralized solution and the actual uncoordinated practices. Casting a water management problem in a multiagent framework allows to exploit the techniques and methods that are already available in this field for solving distributed optimization problems. In particular, in Distributed Constraint Satisfaction Problems (DCSP, see Yokoo et al., 2000), each agent controls some variables according to his own utility function but has to satisfy inter-agent constraints; while in Distributed Constraint Optimization Problems (DCOP, see Modi et al., 2005), the problem is generalized by introducing a global objective function to be optimized that requires a coordination mechanism between the agents. In this work, we apply a DCSP-DCOP based approach to model a steady state hypothetical watershed management problem (Yang et al., 2009), involving several active human agents (i.e. agents who make decisions) and reactive ecological agents (i.e. agents representing

  13. Photovoltaics support distribution feeder

    SciTech Connect

    Barker, P.P.; Bailey, B.; Peterson, A.J. Jr.

    1997-03-01

    The concept of supporting the transmission and distribution (T&D) system with a photovoltaic (PV) distributed energy source has gained increasing attention as the cost of PV energy has declined. Locating a PV system at a strategic point on the distribution feeder can enhance the overall T&D system performance and provide a source of renewable power generation. In such applications, the PV system peak output ranges from a few percent up to about 20 percent of the peak feeder load. A good example of one such project on a line supplied by the Pacific Gas & Electric Co.`s Kerman Substation near Fresno, California. Given the success of this and other projects, Niagara Mohawk Power Corp. (NMPC) will be testing a 100 kW ac output system interconnected with a 13.2 kV distribution feeder to demonstrate PV T&D support concepts in its service territory. The demonstration system construction and operation is to be funded by NMPC, Utility Photovoltaics Group (UPVG) and New York State Energy Research and Development Authority (NYSERDA). AWS Scientific will manage the site construction and be responsible for maintaining, operating and monitoring the performance of the system. As a prerequisite to construction of the system, the NMPC research and development department funded AWS Scientific Inc. (Albany, N.Y.) and Power Technologies Inc. (Schenectady, N.Y.) to investigate the use of PV energy for T&D support applications on its system. The study involved reviewing a large number of distribution circuits throughout NMPC`s service territory to find candidate locations for the 100 kW demonstration project. A key focus of the study was to find a feeder whereby the injection of PV energy provided maximum dispersed generation benefits.

  14. Distributed Experiment Automation System

    NASA Astrophysics Data System (ADS)

    Lebedev, Gennadi

    2003-03-01

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

  15. Bounding Species Distribution Models

    NASA Technical Reports Server (NTRS)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  16. Bounding species distribution models

    USGS Publications Warehouse

    Stohlgren, T.J.; Jarnevich, C.S.; Esaias, W.E.; Morisette, J.T.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used. ?? 2011 Current Zoology.

  17. Multipartite secure state distribution

    SciTech Connect

    Duer, W.; Briegel, H.-J.; Calsamiglia, J.

    2005-04-01

    We introduce the distribution of a secret multipartite entangled state in a real-world scenario as a quantum primitive. We show that in the presence of noisy quantum channels (and noisy control operations), any state chosen from the set of two-colorable graph states (Calderbank-Shor-Steane codewords) can be created with high fidelity while it remains unknown to all parties. This is accomplished by either blind multipartite entanglement purification, which we introduce in this paper, or by multipartite entanglement purification of enlarged states, which offers advantages over an alternative scheme based on standard channel purification and teleportation. The parties are thus provided with a secret resource of their choice for distributed secure applications.

  18. Distributed Agents for Autonomy

    NASA Astrophysics Data System (ADS)

    Blake, Rick; Amigoni, Francesco; Brambilla, Andrea; de la Rosa Steinz, Sonia; Lavagna, Michele; le Duc, Ian; Page, Jonathan; Page, Oliver; Steel, Robin; Wijnands, Quirien

    2010-08-01

    The Distributed Agents for Autonomy (DAFA) Study has been performed for ESA by SciSys UK Ltd, Vega GmbH and Politecnico di Milano. An analysis of past, present and future space missions has been conducted, structured around a set of three pre-defined mission scenarios: Formation Flying, Earth Observation and Planetary Exploration. This analysis led to the definition of a framework of use cases where the application of distributed autonomy seems necessary or appropriate, and a set of metrics that may be used to assess such deployments. Agent technology and architectures were extensively surveyed and the results used to elaborate each of the mission scenarios to the point where a software prototype could be constructed. Such a prototype was developed for a scenario based on the ExoMars mission and this has been used to highlight the advantages of a DAFA approach to the mission architecture.

  19. Towards heterogeneous distributed debugging

    SciTech Connect

    Damodaran-Kamal, S.K.

    1995-04-01

    Several years of research and development in parallel debugger design have given up several techniques, though implemented in a wide range of tools for an equally wide range of systems. This paper is an evaluation of these myriad techniques as applied to the design of a heterogeneous distributed debugger. The evaluation is based on what features users perceive as useful, as well as the ease of implementation of the features using the available technology. A preliminary architecture for such a heterogeneous tool is proposed. Our effort in this paper is significantly different from the other efforts at creating portable and heterogeneous distributed debuggers in that we concentrate on support for all the important issues in parallel debugging, instead of simply concentrating on portability and heterogeneity.

  20. Business size distributions

    NASA Astrophysics Data System (ADS)

    D'Hulst, R.; Rodgers, G. J.

    2001-10-01

    In a recent work, we introduced two models for the dynamics of customers trying to find the business that best corresponds to their expectation for the price of a commodity. In agreement with the empirical data, a power-law distribution for the business sizes was obtained, taking the number of customers of a business as a proxy for its size. Here, we extend one of our previous models in two different ways. First, we introduce a business aggregation rate that is fitness dependent, which allows us to reproduce a spread in empirical data from one country to another. Second, we allow the bankruptcy rate to take a different functional form, to be able to obtain a log-normal distribution with power-law tails for the size of the businesses.

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

    SciTech Connect

    Rizy, D Tom; Li, Fangxing; Li, Huijuan; Adhikari, Sarina; Kueck, John D

    2010-01-01

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

  2. Distributed Computerized Catalog System

    NASA Technical Reports Server (NTRS)

    Borgen, Richard L.; Wagner, David A.

    1995-01-01

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

  3. Distributed array radar

    NASA Astrophysics Data System (ADS)

    Heimiller, R. C.; Belyea, J. E.; Tomlinson, P. G.

    1983-11-01

    Distributed array radar (DAR) is a concept for efficiently accomplishing surveillance and tracking using coherently internetted mini-radars. They form a long baseline, very thinned array and are capable of very accurate location of targets. This paper describes the DAR concept. Factors involving two-way effective gain patterns for deterministic and random DAR arrays are analyzed and discussed. An analysis of factors affecting signal-to-noise ratio is presented and key technical and performance issues are briefly summarized.

  4. Symmetric generalized binomial distributions

    SciTech Connect

    Bergeron, H.; Curado, E. M. F.; Gazeau, J. P.; Rodrigues, Ligia M. C. S. E-mail: evaldo@cbpf.br E-mail: ligia@cbpf.br

    2013-12-15

    In two recent articles, we have examined a generalization of the binomial distribution associated with a sequence of positive numbers, involving asymmetric expressions of probabilities that break the symmetry win-loss. We present in this article another generalization (always associated with a sequence of positive numbers) that preserves the symmetry win-loss. This approach is also based on generating functions and presents constraints of non-negativeness, similar to those encountered in our previous articles.

  5. Distributed proximity sensor system

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan (Inventor)

    1988-01-01

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

  6. Fiber distributed feedback laser

    NASA Technical Reports Server (NTRS)

    Elachi, C.; Evans, G. A.; Yeh, C. (Inventor)

    1976-01-01

    Utilizing round optical fibers as communication channels in optical communication networks presents the problem of obtaining a high efficiency coupling between the optical fiber and the laser. A laser is made an integral part of the optical fiber channel by either diffusing active material into the optical fiber or surrounding the optical fiber with the active material. Oscillation within the active medium to produce lasing action is established by grating the optical fiber so that distributed feedback occurs.

  7. A distributable APSE

    NASA Technical Reports Server (NTRS)

    Taft, Tucker, S.

    1986-01-01

    A distributed Ada program library is a key element in a distributed Ada Program Support Environment (APSE). To implement this successfully, the program library universe as defined by the Ada Reference Manual must be broken up into independently manageable pieces. This in turn requires the support of a distributed database system, as well as a mechanism for identifying compilation units, linkable subprograms, and Ada types in a decentralized way, to avoid falling victim to the bottlenecks of a global database and/or global unique-identifier manager. It was found that the ability to decentralize Ada program library activity is a major advantage in the management of large Ada programs. Currently, there are 18 resource-catalog revision sets, each in its own Host Interface (HIF) partition, plus 18 partitions for testing each of these, plus 11 partitions for the top-level compiler/linker/program library manager components. Compiling and other development work can proceed in parallel in each of these partitions, without suffering the performance bottlenecks of global locks or global unique-identifier generation.

  8. INFERRING THE ECCENTRICITY DISTRIBUTION

    SciTech Connect

    Hogg, David W.; Bovy, Jo; Myers, Adam D.

    2010-12-20

    Standard maximum-likelihood estimators for binary-star and exoplanet eccentricities are biased high, in the sense that the estimated eccentricity tends to be larger than the true eccentricity. As with most non-trivial observables, a simple histogram of estimated eccentricities is not a good estimate of the true eccentricity distribution. Here, we develop and test a hierarchical probabilistic method for performing the relevant meta-analysis, that is, inferring the true eccentricity distribution, taking as input the likelihood functions for the individual star eccentricities, or samplings of the posterior probability distributions for the eccentricities (under a given, uninformative prior). The method is a simple implementation of a hierarchical Bayesian model; it can also be seen as a kind of heteroscedastic deconvolution. It can be applied to any quantity measured with finite precision-other orbital parameters, or indeed any astronomical measurements of any kind, including magnitudes, distances, or photometric redshifts-so long as the measurements have been communicated as a likelihood function or a posterior sampling.

  9. Inferring the Eccentricity Distribution

    NASA Astrophysics Data System (ADS)

    Hogg, David W.; Myers, Adam D.; Bovy, Jo

    2010-12-01

    Standard maximum-likelihood estimators for binary-star and exoplanet eccentricities are biased high, in the sense that the estimated eccentricity tends to be larger than the true eccentricity. As with most non-trivial observables, a simple histogram of estimated eccentricities is not a good estimate of the true eccentricity distribution. Here, we develop and test a hierarchical probabilistic method for performing the relevant meta-analysis, that is, inferring the true eccentricity distribution, taking as input the likelihood functions for the individual star eccentricities, or samplings of the posterior probability distributions for the eccentricities (under a given, uninformative prior). The method is a simple implementation of a hierarchical Bayesian model; it can also be seen as a kind of heteroscedastic deconvolution. It can be applied to any quantity measured with finite precision—other orbital parameters, or indeed any astronomical measurements of any kind, including magnitudes, distances, or photometric redshifts—so long as the measurements have been communicated as a likelihood function or a posterior sampling.

  10. Distributed instruction set computer

    SciTech Connect

    Wang, L.

    1989-01-01

    The Distributed Instruction Set Computer, or DISC for short, is an experimental computer system for fine-grained parallel processing. DISC employs a new parallel instruction set, an Early Binding and Scheduling data tagging scheme, and a distributed control mechanism to explore a software dataflow control method in a multiple-functional unit system. With zero system control overhead, multiple instructions are executed in parallel and/or out of order at the highest speed of n instructions/cycle, where n is the number of functional units. The quantitative simulation result indicates that a DISC system with 16 functional units can deliverer a maximal 7.7X performance speedup over a single functional-unit system at the same clock speed. Exploring a new parallel instruction set and distributed control mechanism, DISC represents three major breakthroughs in the domain of fine-grained parallel processing: (1) Fast multiple instruction issuing mechanism; (2) Parallel and/or out-of-order execution; (3) Software dataflow control scheme.

  11. GASIFICATION FOR DISTRIBUTED GENERATION

    SciTech Connect

    Ronald C. Timpe; Michael D. Mann; Darren D. Schmidt

    2000-05-01

    A recent emphasis in gasification technology development has been directed toward reduced-scale gasifier systems for distributed generation at remote sites. The domestic distributed power generation market over the next decade is expected to be 5-6 gigawatts per year. The global increase is expected at 20 gigawatts over the next decade. The economics of gasification for distributed power generation are significantly improved when fuel transport is minimized. Until recently, gasification technology has been synonymous with coal conversion. Presently, however, interest centers on providing clean-burning fuel to remote sites that are not necessarily near coal supplies but have sufficient alternative carbonaceous material to feed a small gasifier. Gasifiers up to 50 MW are of current interest, with emphasis on those of 5-MW generating capacity. Internal combustion engines offer a more robust system for utilizing the fuel gas, while fuel cells and microturbines offer higher electric conversion efficiencies. The initial focus of this multiyear effort was on internal combustion engines and microturbines as more realistic near-term options for distributed generation. In this project, we studied emerging gasification technologies that can provide gas from regionally available feedstock as fuel to power generators under 30 MW in a distributed generation setting. Larger-scale gasification, primarily coal-fed, has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries. Commercial-scale gasification activities are under way at 113 sites in 22 countries in North and South America, Europe, Asia, Africa, and Australia, according to the Gasification Technologies Council. Gasification studies were carried out on alfalfa, black liquor (a high-sodium waste from the pulp industry), cow manure, and willow on the laboratory scale and on alfalfa, black liquor, and willow on the bench scale. Initial parametric tests

  12. Planning Systems for Distributed Operations

    NASA Technical Reports Server (NTRS)

    Maxwell, Theresa G.

    2002-01-01

    This viewgraph representation presents an overview of the mission planning process involving distributed operations (such as the International Space Station (ISS)) and the computer hardware and software systems needed to support such an effort. Topics considered include: evolution of distributed planning systems, ISS distributed planning, the Payload Planning System (PPS), future developments in distributed planning systems, Request Oriented Scheduling Engine (ROSE) and Next Generation distributed planning systems.

  13. Estimating Dark Matter Distributions

    NASA Astrophysics Data System (ADS)

    Wang, Xiao; Woodroofe, Michael; Walker, Matthew G.; Mateo, Mario; Olszewski, Edward

    2005-06-01

    Thanks to instrumental advances, new, very large kinematic data sets for nearby dwarf spheroidal (dSph) galaxies are on the horizon. A key aim of these data sets is to help determine the distribution of dark matter in these galaxies. Past analyses have generally relied on specific dynamical models or highly restrictive dynamical assumptions. We describe a new, nonparametric analysis of the kinematics of nearby dSph galaxies designed to take full advantage of the future large data sets. The method takes as input the projected positions and radial velocities of stars known to be members of the galaxies but does not use any parametric dynamical model or the assumption that the mass distribution follows that of the visible matter. The problem of estimating the radial mass distribution M(r) (the mass within the true radius r) is converted into a problem of estimating a regression function nonparametrically. From the Jeans equation we show that the unknown regression function is subject to fundamental shape restrictions, which we exploit in our analysis using statistical techniques borrowed from isotonic estimation and spline smoothing. Simulations indicate that M(r) can be estimated to within a factor of 2 or better with samples as small as 1000 stars over almost the entire radial range sampled by the kinematic data. The technique is applied to a sample of 181 stars in the Fornax dSph galaxy. We show that the galaxy contains a significant, extended dark halo some 10 times more massive than its baryonic component. Although applied here to dSph kinematics, this approach can be used in the analysis of any kinematically hot stellar system in which the radial velocity field is discretely sampled.

  14. Representation of orientation distributions

    SciTech Connect

    Wenk, H.R.; Kocks, U.F.

    1985-01-01

    This paper illustrates the principles presented with a particular experimental texture: from the surface layer of a copper polycrystal cold-rolled to 60% reduction in thickness. Four incomplete pole figures (200, 220, 222, and 113) were determined by x-ray diffraction in reflection geometry. The measured pole figures nearly exhibited orthorhombic symmetry (as expected), which was then strictly enforced by averaging the four quadrants of the pole figure. The orientation distribution function was obtained using the expansion in spherical harmonics (with only even-order coefficients up to l = 18).

  15. Distributed Optimization System

    DOEpatents

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2004-11-30

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

  16. Distributed System Design Checklist

    NASA Technical Reports Server (NTRS)

    Hall, Brendan; Driscoll, Kevin

    2014-01-01

    This report describes a design checklist targeted to fault-tolerant distributed electronic systems. Many of the questions and discussions in this checklist may be generally applicable to the development of any safety-critical system. However, the primary focus of this report covers the issues relating to distributed electronic system design. The questions that comprise this design checklist were created with the intent to stimulate system designers' thought processes in a way that hopefully helps them to establish a broader perspective from which they can assess the system's dependability and fault-tolerance mechanisms. While best effort was expended to make this checklist as comprehensive as possible, it is not (and cannot be) complete. Instead, we expect that this list of questions and the associated rationale for the questions will continue to evolve as lessons are learned and further knowledge is established. In this regard, it is our intent to post the questions of this checklist on a suitable public web-forum, such as the NASA DASHLink AFCS repository. From there, we hope that it can be updated, extended, and maintained after our initial research has been completed.

  17. PULSE AMPLITUDE DISTRIBUTION RECORDER

    DOEpatents

    Cowper, G.

    1958-08-12

    A device is described for automatica1ly recording pulse annplitude distribution received from a counter. The novelty of the device consists of the over-all arrangement of conventional circuit elements to provide an easy to read permanent record of the pulse amplitude distribution during a certain time period. In the device a pulse analyzer separates the pulses according to annplitude into several channels. A scaler in each channel counts the pulses and operates a pen marker positioned over a drivable recorder sheet. Since the scalers in each channel have the sanne capacity, the control circuitry permits counting of the incoming pulses until one scaler reaches capacity, whereupon the input is removed and an internal oscillator supplies the necessary pulses to fill up the other scalers. Movement of the chart sheet is initiated wben the first scaler reaches capacity to thereby give a series of marks at spacings proportional to the time required to fill the remaining scalers, and accessory equipment marks calibration points on the recorder sheet to facilitate direct reading of the number of external pulses supplied to each scaler.

  18. Vascular Distribution of Nanomaterials

    PubMed Central

    Stapleton, Phoebe A.; Nurkiewicz, Timothy R.

    2014-01-01

    Once considered primarily occupational, novel nanotechnology innovation and application has led to widespread domestic use and intentional biomedical exposures. With these exciting advances, the breadth and depth of toxicological considerations must also be expanded. The vascular system interacts with every tissue in the body, striving to homeostasis. Engineered nanomaterials (ENM) have been reported to distribute in many different organs and tissues. However, these observations have tended to use approaches requiring tissue homogenization and/or gross organ analyses. These techniques, while effective in establishing presence, preclude an exact determination of where ENM are deposited within a tissue. It is necessary to identify this exact distribution and deposition of ENM throughout the cardiovascular system, with respect to vascular hemodynamics and in vivo/ in vitro ENM modifications taken into account if nanotechnology is to achieve its full potential. Distinct levels of the vasculature will first be described as individual compartments. Then the vasculature will be considered as a whole. These unique compartments and biophysical conditions will be discussed in terms of their propensity to favor ENM deposition. Understanding levels of the vasculature will also be discussed. Ultimately, future studies must verify the mechanisms speculated on and presented herein. PMID:24777845

  19. Coping with distributed computing

    SciTech Connect

    Cormell, L.

    1992-09-01

    The rapid increase in the availability of high performance, cost-effective RISC/UNIX workstations has been both a blessing and a curse. The blessing of having extremely powerful computing engines available on the desk top is well-known to many users. The user has tremendous freedom, flexibility, and control of his environment. That freedom can, however, become the curse of distributed computing. The user must become a system manager to some extent, he must worry about backups, maintenance, upgrades, etc. Traditionally these activities have been the responsibility of a central computing group. The central computing group, however, may find that it can no longer provide all of the traditional services. With the plethora of workstations now found on so many desktops throughout the entire campus or lab, the central computing group may be swamped by support requests. This talk will address several of these computer support and management issues by providing some examples of the approaches taken at various HEP institutions. In addition, a brief review of commercial directions or products for distributed computing and management will be given.

  20. Automated Gas Distribution System

    NASA Astrophysics Data System (ADS)

    Starke, Allen; Clark, Henry

    2012-10-01

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

  1. Distributed Active Archive Center

    NASA Technical Reports Server (NTRS)

    Bodden, Lee; Pease, Phil; Bedet, Jean-Jacques; Rosen, Wayne

    1993-01-01

    The Goddard Space Flight Center Version 0 Distributed Active Archive Center (GSFC V0 DAAC) is being developed to enhance and improve scientific research and productivity by consolidating access to remote sensor earth science data in the pre-EOS time frame. In cooperation with scientists from the science labs at GSFC, other NASA facilities, universities, and other government agencies, the DAAC will support data acquisition, validation, archive and distribution. The DAAC is being developed in response to EOSDIS Project Functional Requirements as well as from requirements originating from individual science projects such as SeaWiFS, Meteor3/TOMS2, AVHRR Pathfinder, TOVS Pathfinder, and UARS. The GSFC V0 DAAC has begun operational support for the AVHRR Pathfinder (as of April, 1993), TOVS Pathfinder (as of July, 1993) and the UARS (September, 1993) Projects, and is preparing to provide operational support for SeaWiFS (August, 1994) data. The GSFC V0 DAAC has also incorporated the existing data, services, and functionality of the DAAC/Climate, DAAC/Land, and the Coastal Zone Color Scanner (CZCS) Systems.

  2. Distributed Operations Planning

    NASA Technical Reports Server (NTRS)

    Fox, Jason; Norris, Jeffrey; Powell, Mark; Rabe, Kenneth; Shams, Khawaja

    2007-01-01

    Maestro software provides a secure and distributed mission planning system for long-term missions in general, and the Mars Exploration Rover Mission (MER) specifically. Maestro, the successor to the Science Activity Planner, has a heavy emphasis on portability and distributed operations, and requires no data replication or expensive hardware, instead relying on a set of services functioning on JPL institutional servers. Maestro works on most current computers with network connections, including laptops. When browsing down-link data from a spacecraft, Maestro functions similarly to being on a Web browser. After authenticating the user, it connects to a database server to query an index of data products. It then contacts a Web server to download and display the actual data products. The software also includes collaboration support based upon a highly reliable messaging system. Modifications made to targets in one instance are quickly and securely transmitted to other instances of Maestro. The back end that has been developed for Maestro could benefit many future missions by reducing the cost of centralized operations system architecture.

  3. Atlas Distributed Analysis Tools

    NASA Astrophysics Data System (ADS)

    de La Hoz, Santiago Gonzalez; Ruiz, Luis March; Liko, Dietrich

    2008-06-01

    The ATLAS production system has been successfully used to run production of simulation data at an unprecedented scale. Up to 10000 jobs were processed in one day. The experiences obtained operating the system on several grid flavours was essential to perform a user analysis using grid resources. First tests of the distributed analysis system were then performed. In the preparation phase data was registered in the LHC File Catalog (LFC) and replicated in external sites. For the main test, few resources were used. All these tests are only a first step towards the validation of the computing model. The ATLAS management computing board decided to integrate the collaboration efforts in distributed analysis in only one project, GANGA. The goal is to test the reconstruction and analysis software in a large scale Data production using Grid flavors in several sites. GANGA allows trivial switching between running test jobs on a local batch system and running large-scale analyses on the Grid; it provides job splitting and merging, and includes automated job monitoring and output retrieval.

  4. Distribution and moments of radial error. [Rayleigh distribution - random variables

    NASA Technical Reports Server (NTRS)

    White, R. G.

    1975-01-01

    An investigation of the moments and probability distribution of the resultant of two normally distributed random variables is presented. This is the so-called generalized Rayleigh distribution which has many applications in the study of wind shear, random noise, and radar. The most general formula was derived, and two special cases were considered for which tables of the moments and probability distribution functions are included as an appendix. One of the special cases was generalized to n-dimensions.

  5. Distributed Wind Energy in Idaho

    SciTech Connect

    Gardner, John; Johnson, Kathryn; Haynes, Todd; Seifert, Gary

    2009-01-31

    This project is a research and development program aimed at furthering distributed wind technology. In particular, this project addresses some of the barriers to distributed wind energy utilization in Idaho.

  6. Distributed charging of electrical assets

    DOEpatents

    Ghosh, Soumyadip; Phan, Dung; Sharma, Mayank; Wu, Chai Wah; Xiong, Jinjun

    2016-02-16

    The present disclosure relates generally to the field of distributed charging of electrical assets. In various examples, distributed charging of electrical assets may be implemented in the form of systems, methods and/or algorithms.

  7. DISTRIBUTED AMPLIFIER INCORPORATING FEEDBACK

    DOEpatents

    Bell, P.R. Jr.

    1958-10-21

    An improved distributed amplifier system employing feedback for stabilization is presented. In accordance with the disclosed invention, a signal to be amplified is applled to one end of a suitable terminated grid transmission line. At intervals along the transmission line, the signal is fed to stable, resistance-capacitance coupled amplifiers incorporating feedback loops therein. The output current from each amplifier is passed through an additional tube to minimize the electrostatic capacitance between the tube elements of the last stage of the amplifier, and fed to appropriate points on an output transmission line, similar to the grid line, but terminated at the opposite (input) end. The output taken from the unterminated end of the plate transmission line is proportional to the input voltage impressed upon the grid line.

  8. Process evaluation distributed system

    NASA Technical Reports Server (NTRS)

    Moffatt, Christopher L. (Inventor)

    2006-01-01

    The distributed system includes a database server, an administration module, a process evaluation module, and a data display module. The administration module is in communication with the database server for providing observation criteria information to the database server. The process evaluation module is in communication with the database server for obtaining the observation criteria information from the database server and collecting process data based on the observation criteria information. The process evaluation module utilizes a personal digital assistant (PDA). A data display module in communication with the database server, including a website for viewing collected process data in a desired metrics form, the data display module also for providing desired editing and modification of the collected process data. The connectivity established by the database server to the administration module, the process evaluation module, and the data display module, minimizes the requirement for manual input of the collected process data.

  9. Unstructured quantum key distribution

    NASA Astrophysics Data System (ADS)

    Coles, Patrick; Metodiev, Eric; Lutkenhaus, Norbert

    Quantum key distribution (QKD) allows for communication with security guaranteed by quantum theory. The main theoretical problem in QKD is to calculate the secret key rate for a given protocol. Analytical formulas are known for protocols with a high degree of symmetry, since symmetry simplifies the analysis. However, experimental imperfections break symmetries, hence the effect of imperfections on key rates is difficult to estimate. Furthermore, it is an interesting question whether (intentionally) asymmetric protocols could outperform symmetric ones. In this work, we develop a robust numerical approach for calculating the key rate for arbitrary discrete-variable QKD protocols. Ultimately this will allow researchers to study ``unstructured'' protocols, i.e., those that lack symmetry. Our approach relies on transforming the key rate calculation to the dual optimization problem, which dramatically reduces the number of parameters and hence the calculation time. We illustrate our method by investigating some unstructured protocols for which the key rate was previously unknown.

  10. Protocols for distributive scheduling

    NASA Technical Reports Server (NTRS)

    Richards, Stephen F.; Fox, Barry

    1993-01-01

    The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of space shuttle mission planning.

  11. Distributed road assessment system

    SciTech Connect

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

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

  12. Carotenoid Distribution in Nature.

    PubMed

    Alcaíno, Jennifer; Baeza, Marcelo; Cifuentes, Víctor

    2016-01-01

    Carotenoids are naturally occurring red, orange and yellow pigments that are synthesized by plants and some microorganisms and fulfill many important physiological functions. This chapter describes the distribution of carotenoid in microorganisms, including bacteria, archaea, microalgae, filamentous fungi and yeasts. We will also focus on their functional aspects and applications, such as their nutritional value, their benefits for human and animal health and their potential protection against free radicals. The central metabolic pathway leading to the synthesis of carotenoids is described as the three following principal steps: (i) the synthesis of isopentenyl pyrophosphate and the formation of dimethylallyl pyrophosphate, (ii) the synthesis of geranylgeranyl pyrophosphate and (iii) the synthesis of carotenoids per se, highlighting the differences that have been found in several carotenogenic organisms and providing an evolutionary perspective. Finally, as an example, the synthesis of the xanthophyll astaxanthin is discussed. PMID:27485217

  13. Sparse distributed memory

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1989-01-01

    Sparse distributed memory was proposed be Pentti Kanerva as a realizable architecture that could store large patterns and retrieve them based on partial matches with patterns representing current sensory inputs. This memory exhibits behaviors, both in theory and in experiment, that resemble those previously unapproached by machines - e.g., rapid recognition of faces or odors, discovery of new connections between seemingly unrelated ideas, continuation of a sequence of events when given a cue from the middle, knowing that one doesn't know, or getting stuck with an answer on the tip of one's tongue. These behaviors are now within reach of machines that can be incorporated into the computing systems of robots capable of seeing, talking, and manipulating. Kanerva's theory is a break with the Western rationalistic tradition, allowing a new interpretation of learning and cognition that respects biology and the mysteries of individual human beings.

  14. Nuclear Parton Distribution Functions

    SciTech Connect

    I. Schienbein, J.Y. Yu, C. Keppel, J.G. Morfin, F. Olness, J.F. Owens

    2009-06-01

    We study nuclear effects of charged current deep inelastic neutrino-iron scattering in the framework of a {chi}{sup 2} analysis of parton distribution functions (PDFs). We extract a set of iron PDFs which are used to compute x{sub Bj}-dependent and Q{sup 2}-dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. We compare our results with nuclear correction factors from neutrino-nucleus scattering models and correction factors for charged-lepton--iron scattering. We find that, except for very high x{sub Bj}, our correction factors differ in both shape and magnitude from the correction factors of the models and charged-lepton scattering.

  15. Distributed feedback lasers

    NASA Technical Reports Server (NTRS)

    Ladany, I.; Andrews, J. T.; Evans, G. A.

    1988-01-01

    A ridge waveguide distributed feedback laser was developed in InGaAsP. These devices have demonstrated CW output powers over 7 mW with threshold currents as low as 60 mA at 25 C. Measurements of the frequency response of these devices show a 3 dB bandwidth of about 2 GHz, which may be limited by the mount. The best devices have a single mode spectra over the entire temperature range tested with a side mode suppression of about 20 dB in both CW and pulsed modes. The design of this device, including detailed modeling of the ridge guide structure, effective index calculations, and a discussion of the grating configuration are presented. Also, the fabrication of the devices is presented in some detail, especially the fabrication of and subsequent growth over the grating. In addition, a high frequency fiber pigtailed package was designed and tested, which is a suitable prototype for a commercial package.

  16. Hail Size Distribution Mapping

    NASA Technical Reports Server (NTRS)

    2008-01-01

    A 3-D weather radar visualization software program was developed and implemented as part of an experimental Launch Pad 39 Hail Monitor System. 3DRadPlot, a radar plotting program, is one of several software modules that form building blocks of the hail data processing and analysis system (the complete software processing system under development). The spatial and temporal mapping algorithms were originally developed through research at the University of Central Florida, funded by NASA s Tropical Rainfall Measurement Mission (TRMM), where the goal was to merge National Weather Service (NWS) Next-Generation Weather Radar (NEXRAD) volume reflectivity data with drop size distribution data acquired from a cluster of raindrop disdrometers. In this current work, we adapted these algorithms to process data from a cluster of hail disdrometers positioned around Launch Pads 39A or 39B, along with the corresponding NWS radar data. Radar data from all NWS NEXRAD sites is archived at the National Climatic Data Center (NCDC). That data can be readily accessed at . 3DRadPlot plots Level III reflectivity data at four scan elevations (this software is available at Open Channel Software, ). By using spatial and temporal interpolation/extrapolation based on hydrometeor fall dynamics, we can merge the hail disdrometer array data coupled with local Weather Surveillance Radar-1988, Doppler (WSR-88D) radial velocity and reflectivity data into a 4-D (3-D space and time) picture of hail size distributions. Hail flux maps can then be generated and used for damage prediction and assessment over specific surfaces corresponding to structures within the disdrometer array volume. Immediately following a hail storm, specific damage areas and degree of damage can be identified for inspection crews.

  17. CMCC Data Distribution Centre

    NASA Astrophysics Data System (ADS)

    Aloisio, Giovanni; Fiore, Sandro; Negro, A.

    2010-05-01

    The CMCC Data Distribution Centre (DDC) is the primary entry point (web gateway) to the CMCC. It is a Data Grid Portal providing a ubiquitous and pervasive way to ease data publishing, climate metadata search, datasets discovery, metadata annotation, data access, data aggregation, sub-setting, etc. The grid portal security model includes the use of HTTPS protocol for secure communication with the client (based on X509v3 certificates that must be loaded into the browser) and secure cookies to establish and maintain user sessions. The CMCC DDC is now in a pre-production phase and it is currently used only by internal users (CMCC researchers and climate scientists). The most important component already available in the CMCC DDC is the Search Engine which allows users to perform, through web interfaces, distributed search and discovery activities by introducing one or more of the following search criteria: horizontal extent (which can be specified by interacting with a geographic map), vertical extent, temporal extent, keywords, topics, creation date, etc. By means of this page the user submits the first step of the query process on the metadata DB, then, she can choose one or more datasets retrieving and displaying the complete XML metadata description (from the browser). This way, the second step of the query process is carried out by accessing to a specific XML document of the metadata DB. Finally, through the web interface, the user can access to and download (partially or totally) the data stored on the storage device accessing to OPeNDAP servers and to other available grid storage interfaces. Requests concerning datasets stored in deep storage will be served asynchronously.

  18. The Saguaro distributed operating system

    NASA Astrophysics Data System (ADS)

    Andrews, Gregory R.; Schlichting, Richard D.

    1989-05-01

    The progress achieved over the final year of the Saguaro distributed operating system project is presented. The primary achievements were in related research, including SR distributed programming language, the MLP system for constructing distributed mixed-language programs, the Psync interprocess communication mechanism, a configurable operating system kernal called the x-kernal, and the development of language mechanisms for performing failure handling in distributed programming languages.

  19. Distributed transit compartments for arbitrary lifespan distributions in aging populations.

    PubMed

    Koch, Gilbert; Schropp, Johannes

    2015-09-01

    Transit compartment models (TCM) are often used to describe aging populations where every individual has its own lifespan. However, in the TCM approach these lifespans are gamma-distributed which is a serious limitation because often the Weibull or more complex distributions are realistic. Therefore, we extend the TCM concept to approximately describe any lifespan distribution and call this generalized concept distributed transit compartment models (DTCMs). The validity of DTCMs is obtained by convergence investigations. From the mechanistic perspective the transit rates are directly controlled by the lifespan distribution. Further, DTCMs could be used to approximate the convolution of a signal with a probability density function. As example a stimulatory effect of a drug in an aging population with a Weibull-distributed lifespan is presented where distribution and model parameters are estimated based on simulated data. PMID:26100181

  20. Correction of Distributed Optical Aberrations

    SciTech Connect

    Baker, K; Olivier, S; Carrano, C; Phillion, D

    2006-02-12

    The objective of this project was to demonstrate the use of multiple distributed deformable mirrors (DMs) to improve the performance of optical systems with distributed aberrations. This concept is expected to provide dramatic improvement in the optical performance of systems in applications where the aberrations are distributed along the optical path or within the instrument itself. Our approach used multiple actuated DMs distributed to match the aberration distribution. The project developed the algorithms necessary to determine the required corrections and simulate the performance of these multiple DM systems.

  1. Distributed visualization framework architecture

    NASA Astrophysics Data System (ADS)

    Mishchenko, Oleg; Raman, Sundaresan; Crawfis, Roger

    2010-01-01

    An architecture for distributed and collaborative visualization is presented. The design goals of the system are to create a lightweight, easy to use and extensible framework for reasearch in scientific visualization. The system provides both single user and collaborative distributed environment. System architecture employs a client-server model. Visualization projects can be synchronously accessed and modified from different client machines. We present a set of visualization use cases that illustrate the flexibility of our system. The framework provides a rich set of reusable components for creating new applications. These components make heavy use of leading design patterns. All components are based on the functionality of a small set of interfaces. This allows new components to be integrated seamlessly with little to no effort. All user input and higher-level control functionality interface with proxy objects supporting a concrete implementation of these interfaces. These light-weight objects can be easily streamed across the web and even integrated with smart clients running on a user's cell phone. The back-end is supported by concrete implementations wherever needed (for instance for rendering). A middle-tier manages any communication and synchronization with the proxy objects. In addition to the data components, we have developed several first-class GUI components for visualization. These include a layer compositor editor, a programmable shader editor, a material editor and various drawable editors. These GUI components interact strictly with the interfaces. Access to the various entities in the system is provided by an AssetManager. The asset manager keeps track of all of the registered proxies and responds to queries on the overall system. This allows all user components to be populated automatically. Hence if a new component is added that supports the IMaterial interface, any instances of this can be used in the various GUI components that work with this

  2. Vacillation Made Easy: Distribution, Re-distribution, and Un-distribution of DOPL-based Processing

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott

    1993-01-01

    Distributed Objects Protocol Layer, or DOPL, Provides a simple and general data communication abstraction that can support the distribution of C++ applications software functionality among an arbitrary collection of processors. The purposed of the abstraction is to minimize the cost of revising processing distribution decisions throughout the software development cycle, including after software has beed delivered to users.

  3. Intraplacental retinol distribution.

    PubMed

    Saunders, Cláudia; Leal, Maria Do Carmo; Flores, Hernando; Soares, Alexandre Gonçalves; De Lima, Ana Paula Pereira Thiapó; Leite, Paula Costa; Gomes, Mirian Martins; De Souza Júnior, Paulo Roberto Borges; Ramalho, Rejane Andréa

    2005-12-01

    With the objective of evaluating intraplacental vitamin A distribution, 234 placental samples were collected, corresponding to six samples from each of the placentas analyzed: two from the lateral maternal portion, one from the central maternal portion, two from the lateral fetal portion, and one from the central fetal portion. Samples were obtained from 39 adult puerperal mothers with low-risk pregnancies, without vitamin A deficiency or night blindness. Retinol content determination was achieved through spectrophotometry. Retinol values obtained for each region were correlated with the most probable value for each placenta (P < 0.001). Despite differences in retinol content between samples, statistical data analysis showed that intra-tissue variation had no influence on the conversion of data into information. Consequently, any portion of the placenta may be used for retinol level determination purposes, due to the correlation between all portions and the most probable value. The findings of the present study represent an advance for surveys intending to incorporate the collection and dosage of placental vitamin A levels into their analyses, thus increasing the arsenal of pre-pathological or subclinical vitamin A deficiency markers, which can allow for earlier intervention on the maternal-infant group. PMID:16638665

  4. The distribution sphere model

    SciTech Connect

    Myers, B.F.; Montgomery, F.C.; Morris, R.N.

    1993-08-01

    The equivalent sphere model, which is widely used in calculating the release of fission gases from nuclear fuel, is idealized. The model is based on the diffusion of fission products in and their escape from a homogeneous sphere of fuel; the fission products are generated at a constant rate and undergo radiodecay. The fuel is assumed to be a set of spherical particles with a common radius. The value of the radius is such that the surface-to-volume ratio, S/V, of the set of spherical particles is the same as the S/V of the fuel mass of interest. The release rate depends on the dimensionless quantity {lambda}a{sup 2}/D where {lambda} is the radiodecay constant, a, the equivalent sphere radius and D, the diffusion coefficient. In the limit {lambda}t {much_gt} 1, the steady-state fractional release for isotopes with half-lives less than about 5 d is given by the familiar relation R/B = 3{radical}D/{lambda}a{sup 2} (1). For the spherical particles, S/V = 3/a. However, in important cases, the assumption of a single value of a is inappropriate. Examples of configurations for which multiple values of a are appropriate include powders, hydrolyzed fuel kernels, normally configured HTR fuel particles and perhaps, fuel kernels alone. In the latter case, one can imagine a distribution of values of a whose mean yields the value appropriate for agreement of Eq. (1) with measurement.

  5. Distributed Observer Network

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA s advanced visual simulations are essential for analyses associated with life cycle planning, design, training, testing, operations, and evaluation. Kennedy Space Center, in particular, uses simulations for ground services and space exploration planning in an effort to reduce risk and costs while improving safety and performance. However, it has been difficult to circulate and share the results of simulation tools among the field centers, and distance and travel expenses have made timely collaboration even harder. In response, NASA joined with Valador Inc. to develop the Distributed Observer Network (DON), a collaborative environment that leverages game technology to bring 3-D simulations to conventional desktop and laptop computers. DON enables teams of engineers working on design and operations to view and collaborate on 3-D representations of data generated by authoritative tools. DON takes models and telemetry from these sources and, using commercial game engine technology, displays the simulation results in a 3-D visual environment. Multiple widely dispersed users, working individually or in groups, can view and analyze simulation results on desktop and laptop computers in real time.

  6. Fuel distribution valve

    SciTech Connect

    Halvorsen, R.M.; Hurst, J.B.

    1986-09-30

    This patent describes a fuel flow distribution valve for dividing and metering fuel flow from a fuel source to nozzles for supplying fuel to an engine comprising valve body means having an inlet and outlets, intermediate liner means forming a longitudinal valve bore in the valve body means. The intermediate liner means has a reference surface thereon, a valve slidably supported in the valve bore slidable longitudinally therein and having a close tolerance diametral fit therewith. The valve has a positioning surface engageable with the reference surface and movable to a spaced apart position therefrom, spring means for biasing the valve in a first direction with respect to the liner means to engage the positioning surface and reference surface. The valve also has a means for directing inlet pressure against the valve in opposition to the spring means, pairs of in line-machined flow metering ports in the liner means and value with the ports in each pair being congruent by virtue of being machined simultaneously with a common tool in the liner means and the valve when the valve is in a fixed position in the bore with the positioning surface spaced a preselected longitudinal distance from the reference surface to define spaced pairs of congruent flow metering ports.

  7. Distribution of contaminants

    SciTech Connect

    Dana, M.T.

    1980-01-01

    Current knowledge of the distribution of atmospheric contaminants is reviewed. Emphasis is placed on regional measurements (those made in areas largely unaffected by local sources). Three specific networks were discussed. The Electric Power Research Institute sponsored Sulfate Regional Experiment (SURE) and the Multi State Atmospheric Power Production Program Study (MAP3S) are networks with event sampling and focus on atmospheric research problems and model verification while the National Atmospheric Deposition Program (NADP) serves to monitor nationwide deposition and dustfall measurements. The MAP3S network was analyzed. No statistically significant trends in concentrations of acid precipitation related pollutants were obtained in the network wide data. Strong positive correlations between the concentrations of acid precipitation related pollutants were obtained from the inland northeast US sites. Midwestern and coastal sites had more complex chemistries which require further study. Several species exhibited seasonal variations: H and SO/sub 4/ had low winter and high summer concentrations; NH/sub 4/ exhibited less variation while NO/sub 3/ appeared constant throughout the year. As a result of differing seasonal trends, the NO/sub 3//SO/sub 4/ ratio varied from 0.3 in the summer to greater than 1 in the winter. 58 references. (MDF)

  8. Data distribution satellite

    NASA Technical Reports Server (NTRS)

    Price, Kent M.; Jorasch, Ronald E.; Wiskerchen, Michael J.

    1991-01-01

    A description is given of a data distribution satellite (DDS) system. The DDS would operate in conjunction with the tracking and data relay satellite system to give ground-based users real time, two-way access to instruments in space and space-gathered data. The scope of work includes the following: (1) user requirements are derived; (2) communication scenarios are synthesized; (3) system design constraints and projected technology availability are identified; (4) DDS communications payload configuration is derived, and the satellite is designed; (5) requirements for earth terminals and network control are given; (6) system costs are estimated, both life cycle costs and user fees; and (7) technology developments are recommended, and a technology development plan is given. The most important results obtained are as follows: (1) a satellite designed for launch in 2007 is feasible and has 10 Gb/s capacity, 5.5 kW power, and 2000 kg mass; (2) DDS features include on-board baseband switching, use of Ku- and Ka-bands, multiple optical intersatellite links; and (3) system user costs are competitive with projected terrestrial communication costs.

  9. Distributed ultrafast fibre laser

    PubMed Central

    Liu, Xueming; Cui, Yudong; Han, Dongdong; Yao, Xiankun; Sun, Zhipei

    2015-01-01

    A traditional ultrafast fibre laser has a constant cavity length that is independent of the pulse wavelength. The investigation of distributed ultrafast (DUF) lasers is conceptually and technically challenging and of great interest because the laser cavity length and fundamental cavity frequency are changeable based on the wavelength. Here, we propose and demonstrate a DUF fibre laser based on a linearly chirped fibre Bragg grating, where the total cavity length is linearly changeable as a function of the pulse wavelength. The spectral sidebands in DUF lasers are enhanced greatly, including the continuous-wave (CW) and pulse components. We observe that all sidebands of the pulse experience the same round-trip time although they have different round-trip distances and refractive indices. The pulse-shaping of the DUF laser is dominated by the dissipative processes in addition to the phase modulations, which makes our ultrafast laser simple and stable. This laser provides a simple, stable, low-cost, ultrafast-pulsed source with controllable and changeable cavity frequency. PMID:25765454

  10. Distributed Merge Trees

    SciTech Connect

    Morozov, Dmitriy; Weber, Gunther

    2013-01-08

    Improved simulations and sensors are producing datasets whose increasing complexity exhausts our ability to visualize and comprehend them directly. To cope with this problem, we can detect and extract significant features in the data and use them as the basis for subsequent analysis. Topological methods are valuable in this context because they provide robust and general feature definitions. As the growth of serial computational power has stalled, data analysis is becoming increasingly dependent on massively parallel machines. To satisfy the computational demand created by complex datasets, algorithms need to effectively utilize these computer architectures. The main strength of topological methods, their emphasis on global information, turns into an obstacle during parallelization. We present two approaches to alleviate this problem. We develop a distributed representation of the merge tree that avoids computing the global tree on a single processor and lets us parallelize subsequent queries. To account for the increasing number of cores per processor, we develop a new data structure that lets us take advantage of multiple shared-memory cores to parallelize the work on a single node. Finally, we present experiments that illustrate the strengths of our approach as well as help identify future challenges.

  11. Distributed Deliberative Recommender Systems

    NASA Astrophysics Data System (ADS)

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

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

  12. LHCb distributed conditions database

    NASA Astrophysics Data System (ADS)

    Clemencic, M.

    2008-07-01

    The LHCb Conditions Database project provides the necessary tools to handle non-event time-varying data. The main users of conditions are reconstruction and analysis processes, which are running on the Grid. To allow efficient access to the data, we need to use a synchronized replica of the content of the database located at the same site as the event data file, i.e. the LHCb Tier1. The replica to be accessed is selected from information stored on LFC (LCG File Catalog) and managed with the interface provided by the LCG developed library CORAL. The plan to limit the submission of jobs to those sites where the required conditions are available will also be presented. LHCb applications are using the Conditions Database framework on a production basis since March 2007. We have been able to collect statistics on the performance and effectiveness of both the LCG library COOL (the library providing conditions handling functionalities) and the distribution framework itself. Stress tests on the CNAF hosted replica of the Conditions Database have been performed and the results will be summarized here.

  13. Voltage regulation in distribution networks with distributed generation

    NASA Astrophysics Data System (ADS)

    Blažič, B.; Uljanić, B.; Papič, I.

    2012-11-01

    The paper deals with the topic of voltage regulation in distribution networks with relatively high distributed energy resources (DER) penetration. The problem of voltage rise is described and different options for voltage regulation are given. The influence of DER on voltage profile and the effectiveness of the investigated solutions are evaluated by means of simulation in DIgSILENT. The simulated network is an actual distribution network in Slovenia with a relatively high penetration of distributed generation. Recommendations for voltage control in networks with DER penetration are given at the end.

  14. Constraining the double gluon distribution by the single gluon distribution

    NASA Astrophysics Data System (ADS)

    Golec-Biernat, Krzysztof; Lewandowska, Emilia; Serino, Mirko; Snyder, Zachary; Staśto, Anna M.

    2015-11-01

    We show how to consistently construct initial conditions for the QCD evolution equations for double parton distribution functions in the pure gluon case. We use to momentum sum rule for this purpose and a specific form of the known single gluon distribution function in the MSTW parameterization. The resulting double gluon distribution satisfies exactly the momentum sum rule and is parameter free. We also study numerically its evolution with a hard scale and show the approximate factorization into product of two single gluon distributions at small values of x, whereas at large values of x the factorization is always violated in agreement with the sum rule.

  15. Data distribution satellite

    NASA Technical Reports Server (NTRS)

    Stevens, Grady H.

    1992-01-01

    The Data Distribution Satellite (DDS), operating in conjunction with the planned space network, the National Research and Education Network and its commercial derivatives, would play a key role in networking the emerging supercomputing facilities, national archives, academic, industrial, and government institutions. Centrally located over the United States in geostationary orbit, DDS would carry sophisticated on-board switching and make use of advanced antennas to provide an array of special services. Institutions needing continuous high data rate service would be networked together by use of a microwave switching matrix and electronically steered hopping beams. Simultaneously, DDS would use other beams and on board processing to interconnect other institutions with lesser, low rate, intermittent needs. Dedicated links to White Sands and other facilities would enable direct access to space payloads and sensor data. Intersatellite links to a second generation ATDRS, called Advanced Space Data Acquisition and Communications System (ASDACS), would eliminate one satellite hop and enhance controllability of experimental payloads by reducing path delay. Similarly, direct access would be available to the supercomputing facilities and national data archives. Economies with DDS would be derived from its ability to switch high rate facilities amongst users needed. At the same time, having a CONUS view, DDS would interconnect with any institution regardless of how remote. Whether one needed high rate service or low rate service would be immaterial. With the capability to assign resources on demand, DDS will need only carry a portion of the resources needed if dedicated facilities were used. Efficiently switching resources to users as needed, DDS would become a very feasible spacecraft, even though it would tie together the space network, the terrestrial network, remote sites, 1000's of small users, and those few who need very large data links intermittently.

  16. Distributed Observer Network

    NASA Technical Reports Server (NTRS)

    Conroy, Michael; Mazzone, Rebecca; Little, William; Elfrey, Priscilla; Mann, David; Mabie, Kevin; Cuddy, Thomas; Loundermon, Mario; Spiker, Stephen; McArthur, Frank; Srey, Tate; Bonilla, Dennis

    2010-01-01

    The Distributed Observer network (DON) is a NASA-collaborative environment that leverages game technology to bring three-dimensional simulations to conventional desktop and laptop computers in order to allow teams of engineers working on design and operations, either individually or in groups, to view and collaborate on 3D representations of data generated by authoritative tools such as Delmia Envision, Pro/Engineer, or Maya. The DON takes models and telemetry from these sources and, using commercial game engine technology, displays the simulation results in a 3D visual environment. DON has been designed to enhance accessibility and user ability to observe and analyze visual simulations in real time. A variety of NASA mission segment simulations [Synergistic Engineering Environment (SEE) data, NASA Enterprise Visualization Analysis (NEVA) ground processing simulations, the DSS simulation for lunar operations, and the Johnson Space Center (JSC) TRICK tool for guidance, navigation, and control analysis] were experimented with. Desired functionalities, [i.e. Tivo-like functions, the capability to communicate textually or via Voice-over-Internet Protocol (VoIP) among team members, and the ability to write and save notes to be accessed later] were targeted. The resulting DON application was slated for early 2008 release to support simulation use for the Constellation Program and its teams. Those using the DON connect through a client that runs on their PC or Mac. This enables them to observe and analyze the simulation data as their schedule allows, and to review it as frequently as desired. DON team members can move freely within the virtual world. Preset camera points can be established, enabling team members to jump to specific views. This improves opportunities for shared analysis of options, design reviews, tests, operations, training, and evaluations, and improves prospects for verification of requirements, issues, and approaches among dispersed teams.

  17. Distribution of tsunami interevent times

    USGS Publications Warehouse

    Geist, E.L.; Parsons, T.

    2008-01-01

    The distribution of tsunami interevent times is analyzed using global and site-specific (Hilo, Hawaii) tsunami catalogs. An empirical probability density distribution is determined by binning the observed interevent times during a period in which the observation rate is approximately constant. The empirical distributions for both catalogs exhibit non-Poissonian behavior in which there is an abundance of short interevent times compared to an exponential distribution. Two types of statistical distributions are used to model this clustering behavior: (1) long-term clustering described by a universal scaling law, and (2) Omori law decay of aftershocks and triggered sources. The empirical and theoretical distributions all imply an increased hazard rate after a tsunami, followed by a gradual decrease with time approaching a constant hazard rate. Examination of tsunami sources suggests that many of the short interevent times are caused by triggered earthquakes, though the triggered events are not necessarily on the same fault.

  18. Distribution system harmonic filter planning

    SciTech Connect

    Ortmeyer, T.H.; Hiyama, Takashi

    1996-10-01

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

  19. Audio distribution and Monitoring Circuit

    NASA Technical Reports Server (NTRS)

    Kirkland, J. M.

    1983-01-01

    Versatile circuit accepts and distributes TV audio signals. Three-meter audio distribution and monitoring circuit provides flexibility in monitoring, mixing, and distributing audio inputs and outputs at various signal and impedance levels. Program material is simultaneously monitored on three channels, or single-channel version built to monitor transmitted or received signal levels, drive speakers, interface to building communications, and drive long-line circuits.

  20. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  1. Distribution of Clokey's Eggvetch

    SciTech Connect

    David C. Anderson

    1998-12-01

    monophylla), Utah juniper (Juniperus osteosperma), and big sagebrush (Artemisia tridentata ssp. tridentata). Overall, the populations of Clokey's eggvetch on the NTS appear to be vigorous and do not appear threatened. It is estimated that there are approximately 2300 plants on the NTS. It should be considered as a species of concern because of its localized distribution, but it does not appear to warrant protection under the ESA.

  2. Recoverable distributed shared virtual memory

    NASA Technical Reports Server (NTRS)

    Wu, Kun-Lung; Fuchs, W. Kent

    1990-01-01

    The problem of rollback recovery in distributed shared virtual environments, in which the shared memory is implemented in software in a loosely coupled distributed multicomputer system, is examined. A user-transparent checkpointing recovery scheme and a new twin-page disk storage management technique are presented for implementing recoverable distributed shared virtual memory. The checkpointing scheme can be integrated with the memory coherence protocol for managing the shared virtual memory. The twin-page disk design allows checkpointing to proceed in an incremental fashion without an explicit undo at the time of recovery. The recoverable distributed shared virtual memory allows the system to restart computation from a checkpoint without a global restart.

  3. Space platform utilities distribution study

    NASA Technical Reports Server (NTRS)

    Lefever, A. E.

    1980-01-01

    Generic concepts for the installation of power data and thermal fluid distribution lines on large space platforms were discussed. Connections with central utility subsystem modules and pallet interfaces were also considered. Three system concept study platforms were used as basepoints for the detail development. The tradeoff of high voltage low voltage power distribution and the impact of fiber optics as a data distribution mechanism were analyzed. Thermal expansion and temperature control of utility lines and ducts were considered. Technology developments required for implementation of the generic distribution concepts were identified.

  4. A four-way distribution amplifier for reference signal distribution

    NASA Technical Reports Server (NTRS)

    Lo, Y. V.

    1981-01-01

    A four way distribution amplifier with up to 100 dB isolation and with low phase noise of -140 dBc in a 1 Hz bandwidth 10 Hz from a 100 MHz signal was developed. It is to be used in the stabilized optical fiber distribution system to provide multiple outputs.

  5. Current Perspectives in Distributive Education.

    ERIC Educational Resources Information Center

    Klaurens, Mary K., Ed.; Trapnell, Gail, Ed.

    The volume on current perspectives in distributive education contains 29 individually authored articles organized into three sections. The first section on program conceptualization deals with the following subjects: the evolution of distributive education, program planning, advisory committees, placement services, postsecondary distributive…

  6. The Future of Distributed Leadership

    ERIC Educational Resources Information Center

    Gronn, Peter

    2008-01-01

    Purpose: This paper aims to assess the empirical utility and conceptual significance of distributed leadership. Design/methodology/approach: Three main sources of evidence are drawn on. The paper reviews some neglected commentary of an early generation of distributed leadership theorists. It also discusses a strand of social science writings on…

  7. Water Treatment Technology - Distribution Systems.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

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

  8. Reduplication and Distributivity in Kannada

    ERIC Educational Resources Information Center

    Anderson, Janet Katherine

    2012-01-01

    Reduplication of numerals and pronouns in Kannada is shown to be subject to locality conditions similar to those constraining binding. This dissertation explores an account of distributivity which exploits the similarity to binding, arguing that the source of the distributive reading in Numeral Reduplication is a bound element. [The dissertation…

  9. Leadership in Partially Distributed Teams

    ERIC Educational Resources Information Center

    Plotnick, Linda

    2009-01-01

    Inter-organizational collaboration is becoming more common. When organizations collaborate they often do so in partially distributed teams (PDTs). A PDT is a hybrid team that has at least one collocated subteam and at least two subteams that are geographically distributed and communicate primarily through electronic media. While PDTs share many…

  10. Workload Distribution among Agriculture Teachers

    ERIC Educational Resources Information Center

    Torres, Robert M.; Ulmer, Jonathan D.; Aschenbrener, Mollie S.

    2008-01-01

    Teachers distribute their time in many ways. The study sought to determine how agriculture teachers distribute their time among 11 selected teacher activities (i.e., preparation for instruction; classroom/laboratory teaching; laboratory preparation and/or maintenance; grading/scoring students' work; administrative duties-program management;…

  11. Distributed Leadership: Friend or Foe?

    ERIC Educational Resources Information Center

    Harris, Alma

    2013-01-01

    Distributed leadership is now widely known and variously enacted in schools and school systems. Distributed leadership implies a fundamental re-conceptualisation of leadership as practice and challenges conventional wisdom about the relationship between formal leadership and organisational performance. There has been much debate, speculation and…

  12. COS NUV MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2013-10-01

    The performance of the MAMA microchannel plate can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as Cycle 20 proposal 13128.

  13. Quality monitored distributed voting system

    DOEpatents

    Skogmo, D.

    1997-03-18

    A quality monitoring system can detect certain system faults and fraud attempts in a distributed voting system. The system uses decoy voters to cast predetermined check ballots. Absent check ballots can indicate system faults. Altered check ballots can indicate attempts at counterfeiting votes. The system can also cast check ballots at predetermined times to provide another check on the distributed voting system. 6 figs.

  14. Quality monitored distributed voting system

    DOEpatents

    Skogmo, David

    1997-01-01

    A quality monitoring system can detect certain system faults and fraud attempts in a distributed voting system. The system uses decoy voters to cast predetermined check ballots. Absent check ballots can indicate system faults. Altered check ballots can indicate attempts at counterfeiting votes. The system can also cast check ballots at predetermined times to provide another check on the distributed voting system.

  15. Quasistationary distributions for autocatalytic reactions

    SciTech Connect

    Parsons, R.W.; Pollett, P.K.

    1987-01-01

    The authors provide simple conditions for the existence of quasistationary distributions that can be used to describe the long-term behavior of open autocatalytic reaction systems. They illustrate with reference to a particular example that the quasistationary distribution is close to the usual stationary diffusion approximation.

  16. 2014 Distributed Wind Market Report

    SciTech Connect

    Orell, A.; Foster, N.

    2015-08-01

    The cover of the 2014 Distributed Wind Market Report.According to the 2014 Distributed Wind Market Report, distributed wind reached a cumulative capacity of almost 1 GW (906 MW) in the United States in 2014, reflecting nearly 74,000 wind turbines deployed across all 50 states, Puerto Rico, and the U.S. Virgin Islands. In total, 63.6 MW of new distributed wind capacity was added in 2014, representing nearly 1,700 units and $170 million in investment across 24 states. In 2014, America's distributed wind energy industry supported a growing domestic industrial base as exports from United States-based small wind turbine manufacturers accounted for nearly 80% of United States-based manufacturers' sales.

  17. Power Law Distribution in Education

    NASA Astrophysics Data System (ADS)

    Gupta, Hari M.; Campanha, José R.; Chavarette, Fábio R.

    We studied the statistical distribution of student's performance, which is measured through their marks, in university entrance examination (Vestibular) of UNESP (Universidade Estadual Paulista) with respect to (i) period of study-day versus night period (ii) teaching conditions - private versus public school (iii) economical conditions - high versus low family income. We observed long ubiquitous power law tails in physical and biological sciences in all cases. The mean value increases with better study conditions followed by better teaching and economical conditions. In humanities, the distribution is close to normal distribution with very small tail. This indicates that these power law tails in science subjects are due to the nature of the subjects themselves. Further and better study, teaching and economical conditions are more important for physical and biological sciences in comparison to humanities at this level of study. We explain these statistical distributions through Gradually Truncated Power law distributions. We discuss the possible reason for this peculiar behavior.

  18. Size distribution of ring polymers

    NASA Astrophysics Data System (ADS)

    Medalion, Shlomi; Aghion, Erez; Meirovitch, Hagai; Barkai, Eli; Kessler, David A.

    2016-06-01

    We present an exact solution for the distribution of sample averaged monomer to monomer distance of ring polymers. For non-interacting and local-interaction models these distributions correspond to the distribution of the area under the reflected Bessel bridge and the Bessel excursion respectively, and are shown to be identical in dimension d ≥ 2, albeit with pronounced finite size effects at the critical dimension, d = 2. A symmetry of the problem reveals that dimension d and 4 ‑ d are equivalent, thus the celebrated Airy distribution describing the areal distribution of the d = 1 Brownian excursion describes also a polymer in three dimensions. For a self-avoiding polymer in dimension d we find numerically that the fluctuations of the scaled averaged distance are nearly identical in dimension d = 2, 3 and are well described to a first approximation by the non-interacting excursion model in dimension 5.

  19. Distribution System Voltage Regulation by Distributed Energy Resources

    SciTech Connect

    Ceylan, Oguzhan; Liu, Guodong; Xu, Yan; Tomsovic, Kevin

    2014-01-01

    This paper proposes a control method to regulate voltages in 3 phase unbalanced electrical distribution systems. A constrained optimization problem to minimize voltage deviations and maximize distributed energy resource (DER) active power output is solved by harmony search algorithm. IEEE 13 Bus Distribution Test System was modified to test three different cases: a) only voltage regulator controlled system b) only DER controlled system and c) both voltage regulator and DER controlled system. The simulation results show that systems with both voltage regulators and DER control provide better voltage profile.

  20. Marketing and Distribution: Developing Career Interests in Distributive Education

    ERIC Educational Resources Information Center

    Searle, A. Gary

    1978-01-01

    The author discusses a variety of commercial interest inventories which may be used by the distributive education teacher-coordinator to guide students in exploring careers in the marketing cluster. ( MF)

  1. Lunar soil grain size distribution

    NASA Technical Reports Server (NTRS)

    Carrier, W. D., III

    1973-01-01

    A comprehensive review has been made of the currently available data for lunar grain size distributions. It has been concluded that there is little or no statistical difference among the large majority of the soil samples from the Apollo 11, 12, 14, and 15 missions. The grain size distribution for these soils has reached a steady state in which the comminution processes are balanced by the aggregation processes. The median particle size for the steady-state soil is 40 to 130 microns. The predictions of lunar grain size distributions based on the Surveyor television photographs have been found to be quantitatively in error and qualitatively misleading.

  2. Packing fraction of continuous distributions

    NASA Astrophysics Data System (ADS)

    Brouwers, Jos

    2014-03-01

    This study addresses the packing and void fraction of polydisperse particles with geometric and lognormal size distribution. It is demonstrated that a bimodal discrete particle distribution can be transformed into said continuous particle-size distributions. Furthermore, original and exact expressions are presented that predict the packing fraction of these particle assemblies. For a number of particle shapes and their packing modes (close, loose) the applicable parameters are given. The closed-form analytical expression governing the packing fractions are thoroughly compared with empirical and computational data reported in the literature, and good agreement is found.

  3. Valence quark spin distribution functions

    SciTech Connect

    Nathan Isgur

    1998-09-01

    The hyperfine interactions of the constituent quark model provide a natural explanation for many nucleon properties, including the {Delta} - N splitting, the charge radius of the neutron, and the observation that the proton's quark distribution function ratio d(x)/u(x) {r_arrow} 0 as x {r_arrow} 1. The hyperfine-perturbed quark model also makes predictions for the nucleon spin-dependent distribution functions. Precision measurements of the resulting asymmetries A{sub 1}{sup p}(x) and A{sub 1}{sup n}(x) in the valence region can test this model and thereby the hypothesis that the valence quark spin distributions are ''normal''.

  4. Exploiting replication in distributed systems

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    Techniques are examined for replicating data and execution in directly distributed systems: systems in which multiple processes interact directly with one another while continuously respecting constraints on their joint behavior. Directly distributed systems are often required to solve difficult problems, ranging from management of replicated data to dynamic reconfiguration in response to failures. It is shown that these problems reduce to more primitive, order-based consistency problems, which can be solved using primitives such as the reliable broadcast protocols. Moreover, given a system that implements reliable broadcast primitives, a flexible set of high-level tools can be provided for building a wide variety of directly distributed application programs.

  5. A prototype Distributed Audit System

    SciTech Connect

    Banning, D.L.

    1993-08-01

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

  6. The alignment-distribution graph

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert

    1993-01-01

    Implementing a data-parallel language such as Fortran 90 on a distributed-memory parallel computer requires distributing aggregate data objects (such as arrays) among the memory modules attached to the processors. The mapping of objects to the machine determines the amount of residual communication needed to bring operands of parallel operations into alignment with each other. We present a program representation called the alignment distribution graph that makes these communication requirements explicit. We describe the details of the representation, show how to model communication cost in this framework, and outline several algorithms for determining object mappings that approximately minimize residual communication.

  7. The alignment-distribution graph

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert

    1993-01-01

    Implementing a data-parallel language such as Fortran 90 on a distributed-memory parallel computer requires distributing aggregate data objects (such as arrays) among the memory modules attached to the processors. The mapping of objects to the machine determines the amount of residual communication needed to bring operands of parallel operations into alignment with each other. We present a program representation called the alignment-distribution graph that makes these communication requirements explicit. We describe the details of the representation, show how to model communication cost in this framework, and outline several algorithms for determining object mappings that approximately minimize residual communication.

  8. Wealth distribution on complex networks

    NASA Astrophysics Data System (ADS)

    Ichinomiya, Takashi

    2012-12-01

    We study the wealth distribution of the Bouchaud-Mézard model on complex networks. It is known from numerical simulations that this distribution depends on the topology of the network; however, no one has succeeded in explaining it. Using “adiabatic” and “independent” assumptions along with the central-limit theorem, we derive equations that determine the probability distribution function. The results are compared to those of simulations for various networks. We find good agreement between our theory and the simulations, except for the case of Watts-Strogatz networks with a low rewiring rate due to the breakdown of independent assumption.

  9. Dose distributions in regions containing beta sources: Irregularly shaped source distributions in homogeneous media

    SciTech Connect

    Werner, B.L. )

    1991-11-01

    Methods are introduced by which dose rate distributions due to nonuniform, irregularly shaped distributions of beta emitters can be calculated using dose rate distributions for uniform, spherical source distributions. The dose rate distributions can be written in the MIRD formalism.

  10. The Raid distributed database system

    NASA Technical Reports Server (NTRS)

    Bhargava, Bharat; Riedl, John

    1989-01-01

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

  11. BESIII production with distributed computing

    NASA Astrophysics Data System (ADS)

    Zhang, X. M.; Yan, T.; Zhao, X. H.; Ma, Z. T.; Yan, X. F.; Lin, T.; Deng, Z. Y.; Li, W. D.; Belov, S.; Pelevanyuk, I.; Zhemchugov, A.; Cai, H.

    2015-12-01

    Distributed computing is necessary nowadays for high energy physics experiments to organize heterogeneous computing resources all over the world to process enormous amounts of data. The BESIII experiment in China, has established its own distributed computing system, based on DIRAC, as a supplement to local clusters, collecting cluster, grid, desktop and cloud resources from collaborating member institutes around the world. The system consists of workload management and data management to deal with the BESIII Monte Carlo production workflow in a distributed environment. A dataset-based data transfer system has been developed to support data movements among sites. File and metadata management tools and a job submission frontend have been developed to provide a virtual layer for BESIII physicists to use distributed resources. Moreover, the paper shows the experience to cope with lack of grid experience and low manpower among the BESIII community.

  12. Fact Program - distributed exhaust nozzle

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Futuristic Airframe Concepts & Technology (FACT): Distributed exhaust nozzle mounted in the Low Speed Aeroacoustic Wind Tunnel. Angle is zero degrees with respect to microphones. Photographed in the Low Speed Aeroacoustic Wind Tunnel, Jet Noise Lab, building 1221-A.

  13. Multiple complementary gas distribution assemblies

    DOEpatents

    Ng, Tuoh-Bin; Melnik, Yuriy; Pang, Lily L; Tuncel, Eda; Nguyen, Son T; Chen, Lu

    2016-04-05

    In one embodiment, an apparatus includes a first gas distribution assembly that includes a first gas passage for introducing a first process gas into a second gas passage that introduces the first process gas into a processing chamber and a second gas distribution assembly that includes a third gas passage for introducing a second process gas into a fourth gas passage that introduces the second process gas into the processing chamber. The first and second gas distribution assemblies are each adapted to be coupled to at least one chamber wall of the processing chamber. The first gas passage is shaped as a first ring positioned within the processing chamber above the second gas passage that is shaped as a second ring positioned within the processing chamber. The gas distribution assemblies may be designed to have complementary characteristic radial film growth rate profiles.

  14. Distribution and flux of micrometeoroids

    NASA Technical Reports Server (NTRS)

    Morrison, D. A.; Zinner, E.

    1977-01-01

    The mass distribution, flux, and distribution in space of the micrometeoroid complex at 1 AU are estimated on the basis of data from Apollo 17 rocks and recent calibrations of solar-flare track-production rates. It is found that the size frequency distribution of microcraters on lunar rocks suggests a bimodal mass distribution of micrometeoroids, but the precise form of the curve requires further definition, particularly insofar as the degree of depletion of particles producing craters 10 to 100 microns in diameter is concerned. Variations in slope with crater-diameter or particle-mass increments are shown to indicate that different processes affect one or more particle populations. Fluxes corresponding to varied lunar surface orientation and residence time are calculated, but no striking difference is observed between the flux of submicron-diameter particles with orbits in the plane of the ecliptic and fluxes of particles with orbits normal to the plane in the solar apex direction.

  15. 2013 Distributed Wind Market Report

    SciTech Connect

    Orrell, Alice C.; Rhoads-Weaver, H. E.; Flowers, Larry T.; Gagne, Matthew N.; Pro, Boyd H.; Foster, Nikolas AF

    2014-08-20

    The purpose of this report is to quantify and summarize the 2013 U.S. distributed wind market to help plan and guide future investments and decisions by industry stakeholders, utilities, state and federal agencies, and other interested parties.

  16. The Binomial Distribution in Shooting

    ERIC Educational Resources Information Center

    Chalikias, Miltiadis S.

    2009-01-01

    The binomial distribution is used to predict the winner of the 49th International Shooting Sport Federation World Championship in double trap shooting held in 2006 in Zagreb, Croatia. The outcome of the competition was definitely unexpected.

  17. Performance of distributed multiscale simulations

    PubMed Central

    Borgdorff, J.; Ben Belgacem, M.; Bona-Casas, C.; Fazendeiro, L.; Groen, D.; Hoenen, O.; Mizeranschi, A.; Suter, J. L.; Coster, D.; Coveney, P. V.; Dubitzky, W.; Hoekstra, A. G.; Strand, P.; Chopard, B.

    2014-01-01

    Multiscale simulations model phenomena across natural scales using monolithic or component-based code, running on local or distributed resources. In this work, we investigate the performance of distributed multiscale computing of component-based models, guided by six multiscale applications with different characteristics and from several disciplines. Three modes of distributed multiscale computing are identified: supplementing local dependencies with large-scale resources, load distribution over multiple resources, and load balancing of small- and large-scale resources. We find that the first mode has the apparent benefit of increasing simulation speed, and the second mode can increase simulation speed if local resources are limited. Depending on resource reservation and model coupling topology, the third mode may result in a reduction of resource consumption. PMID:24982258

  18. Visualizing Spatially Varying Distribution Data

    NASA Technical Reports Server (NTRS)

    Kao, David; Luo, Alison; Dungan, Jennifer L.; Pang, Alex; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Box plot is a compact representation that encodes the minimum, maximum, mean, median, and quarters information of a distribution. In practice, a single box plot is drawn for each variable of interest. With the advent of more accessible computing power, we are now facing the problem of visual icing data where there is a distribution at each 2D spatial location. Simply extending the box plot technique to distributions over 2D domain is not straightforward. One challenge is reducing the visual clutter if a box plot is drawn over each grid location in the 2D domain. This paper presents and discusses two general approaches, using parametric statistics and shape descriptors, to present 2D distribution data sets. Both approaches provide additional insights compared to the traditional box plot technique

  19. Distributed processing for speech understanding

    SciTech Connect

    Bronson, E.C.; Siegel, L.

    1983-01-01

    Continuous speech understanding is a highly complex artificial intelligence task requiring extensive computation. This complexity precludes real-time speech understanding on a conventional serial computer. Distributed processing technique can be applied to the speech understanding task to improve processing speed. In the paper, the speech understanding task and several speech understanding systems are described. Parallel processing techniques are presented and a distributed processing architecture for speech understanding is outlined. 35 references.

  20. UNIX code management and distribution

    SciTech Connect

    Hung, T.; Kunz, P.F.

    1992-09-01

    We describe a code management and distribution system based on tools freely available for the UNIX systems. At the master site, version control is managed with CVS, which is a layer on top of RCS, and distribution is done via NFS mounted file systems. At remote sites, small modifications to CVS provide for interactive transactions with the CVS system at the master site such that remote developers are true peers in the code development process.

  1. Structure functions and parton distributions

    SciTech Connect

    Martin, A.D.; Stirling, W.J.; Roberts, R.G.

    1995-07-01

    The MRS parton distribution analysis is described. The latest sets are shown to give an excellent description of a wide range of deep-inelastic and other hard scattering data. Two important theoretical issues-the behavior of the distributions at small x and the flavor structure of the quark sea-are discussed in detail. A comparison with the new structure function data from HERA is made, and the outlook for the future is discussed.

  2. Generalized parton distributions in nuclei

    SciTech Connect

    Vadim Guzey

    2009-12-01

    Generalized parton distributions (GPDs) of nuclei describe the distribution of quarks and gluons in nuclei probed in hard exclusive reactions, such as e.g. deeply virtual Compton scattering (DVCS). Nuclear GPDs and nuclear DVCS allow us to study new aspects of many traditional nuclear effects (nuclear shadowing, EMC effect, medium modifications of the bound nucleons) as well as to access novel nuclear effects. In my talk, I review recent theoretical progress in the area of nuclear GPDs.

  3. COS NUV MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2010-09-01

    The performance of the MAMA microchannel plate can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the COS MAMA Fold Analysis {11891} during Cycle 17.

  4. COS NUV MAMA Fold Distribution

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2012-10-01

    The performance of the MAMA microchannel plate can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the COS MAMA Fold Analysis {12723} during Cycle 19.

  5. Modeling Nucleon Generalized Parton Distributions

    SciTech Connect

    Radyushkin, Anatoly V.

    2013-05-01

    We discuss building models for nucleon generalized parton distributions (GPDs) H and E that are based on the formalism of double distributions (DDs). We find that the usual "DD+D-term'' construction should be amended by an extra term, generated by GPD E(x,\\xi). Unlike the $D$-term, this function has support in the whole -1 < x< 1 region, and in general does not vanish at the border points|x|=\\xi.

  6. The ATLAS distributed analysis system

    NASA Astrophysics Data System (ADS)

    Legger, F.; Atlas Collaboration

    2014-06-01

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

  7. Double distributions and evolution equations

    SciTech Connect

    A.V. Radyushkin

    1998-05-01

    Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive meson electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements < p{prime} {vert_bar}O(0,z){vert_bar}p > of quark and gluon light-cone operators. In their previous papers the authors used two types of nonperturbative functions parameterizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F{sub {zeta}}(X;t). Here they discuss in more detail the double distributions (DD's) and evolution equations which they satisfy. They propose simple models for F(x,y;t=0) DD's with correct spectral and symmetry properties which also satisfy the reduction relations connecting them to the usual parton densities f(x). In this way, they obtain self-consistent models for the {zeta}-dependence of nonforward distributions. They show that, for small {zeta}, one can easily obtain nonforward distributions (in the X > {zeta} region) from the parton densities: F{sub {zeta}} (X;t=0) {approx} f(X{minus}{zeta}/2).

  8. Distribution functions of probabilistic automata

    NASA Technical Reports Server (NTRS)

    Vatan, F.

    2001-01-01

    Each probabilistic automaton M over an alphabet A defines a probability measure Prob sub(M) on the set of all finite and infinite words over A. We can identify a k letter alphabet A with the set {0, 1,..., k-1}, and, hence, we can consider every finite or infinite word w over A as a radix k expansion of a real number X(w) in the interval [0, 1]. This makes X(w) a random variable and the distribution function of M is defined as usual: F(x) := Prob sub(M) { w: X(w) < x }. Utilizing the fixed-point semantics (denotational semantics), extended to probabilistic computations, we investigate the distribution functions of probabilistic automata in detail. Automata with continuous distribution functions are characterized. By a new, and much more easier method, it is shown that the distribution function F(x) is an analytic function if it is a polynomial. Finally, answering a question posed by D. Knuth and A. Yao, we show that a polynomial distribution function F(x) on [0, 1] can be generated by a prob abilistic automaton iff all the roots of F'(x) = 0 in this interval, if any, are rational numbers. For this, we define two dynamical systems on the set of polynomial distributions and study attracting fixed points of random composition of these two systems.

  9. The RHESSI Microflare Height Distribution

    NASA Technical Reports Server (NTRS)

    Christe, P.; Krucker, S.; Saint-Hilaire, P.

    2011-01-01

    We present the first in-depth statistical survey of flare source heights observed by RHESSI. Flares were found using a flare-finding algorithm designed to search the 6-10 keV count-rate when RHESSI's full sensitivity was available in order to find the smallest events (Christe et al., 2008). Between March 2002 and March 2007, a total of 25,006 events were found. Source locations were determined in the 4-10 keV, 10-15 keV, and 15-30 keV energy ranges for each event. In order to extract the height distribution from the observed projected source positions, a forward-fit model was developed with an assumed source height distribution where height is measured from the photosphere. We find that the best flare height distribution is given by g (h) oc exp(-h/lambda) where lambda = 6.1 plus or minus 0.3 Mm is the scale height. A power law height distribution with a negative power law index, gamma = 3.1 plus or minus 0.3 is also consistent with the data. Interpreted as thermal loop top sources, these heights are compared to loops generated by a potential field model (PFSS). The measured flare heights distribution are found to be much steeper than the potential field loop height distribution which may be a signature of the flare energization process.

  10. Distribution System of the Future

    SciTech Connect

    Kueck, JD

    2003-04-23

    The distribution system of the future is going to be as much of a revolution to the electric energy industry as the wireless telephone has been to consumer communications. An electricity market transformation must occur before the changes can take place, but this evolution is already starting to occur in many parts of the country. In this paper, we discuss a vision for a future distribution system, areas that will be key for technology development, and the advantages of the new electricity market. Present day distribution systems are in a sense, unintelligent. Distribution systems respond to faults, or short circuits, by sensing the very high fault current and then opening circuit breakers to isolate the fault. Some newer automated systems determine fault location and then close other circuit breakers to provide an alternate path for power after the fault so that the number of customers left without power is minimized, but the extent of the reconfiguration is limited. Distribution systems also have some methods to regulate voltage, but there is little real time local response to contingencies such as loss of a transmission line or a generator. In present day distribution systems, there is very little control of load, or demand response, and Distributed Energy Resources (DER, distributed generation, storage, and responsive load) located in the distribution system are prohibited from even regulating voltage. In fact, industry standards and utility interconnection agreements typically require that when a contingency occurs on a distribution or transmission system that results in a voltage or frequency excursion, the DER is to disconnect rather than help. There is a pressing need to evolve the distribution system model to one that can respond to contingencies sensed locally, and has the local intelligence and autonomy to deal with contingencies such as unusual loading, transmission congestion, and line outages. Markets must be simple for customers to participate in the

  11. Fluorescence lifetime distributions in proteins.

    PubMed Central

    Alcala, J. R.; Gratton, E.; Prendergast, F. G.

    1987-01-01

    The fluorescence lifetime value of tryptophan residues varies by more than a factor of 100 in different proteins and is determined by several factors, which include solvent exposure and interactions with other elements of the protein matrix. Because of the variety of different elements that can alter the lifetime value and the sensitivity to the particular environment of the tryptophan residue, it is likely that non-unique lifetime values result in protein systems. The emission decay of most proteins can be satisfactorily described only using several exponential components. Here it is proposed that continuous lifetime distributions can better represent the observed decay. An approach based on protein dynamics is presented, which provides fluorescence lifetime distribution functions for single tryptophan residue proteins. First, lifetime distributions for proteins interconverting between two conformations, each characterized by a different lifetime value, are derived. The evolution of the lifetime values as a function of the interconversion rate is studied. In this case lifetime distributions can be obtained from a distribution of rates of interconversion between the two conformations. Second, the existence of a continuum of energy substates within a given conformation was considered. The occupation of a particular energy substate at a given temperature is proportional to the Boltzmann factor. The density of energy states of the potential well depends upon the width of the well, which determines the degree of freedom the residue can move in the conformational space. Lifetime distributions can be obtained by association of each energy substate with a different lifetime value and assuming that the average conformation can change as the energy of the substate is increased. Finally, lifetime distributions for proteins interconverting between two conformations, each characterized by a quasi-continuum of energy substates, are presented. The origin of negative components

  12. Knowledge in a distributed environment

    SciTech Connect

    Moses, Y.O.

    1986-01-01

    The distributed nature of information in a distributed system is one of the major issues that protocols for cooperation and coordination between individual components in such a system must handle. Individual sites customarily have only partial knowledge about the general state of the system. Moreover, different information is available at the different sites of the system. Consequently, a central role of communication in such protocols is to inform particular sites about events that take place at other sites, and to transform the system's state of knowledge in a way that will guarantee the successful achievement of the goals of the protocol. This thesis is an initial attempt to study the role of knowledge in distributed system. A general framework is presented for defining knowledge in a distributed system, and a variety of states of knowledge are identified that groups of processors may have. These states of knowledge seem to capture basic aspects of coordinated actions in a distributed environment. This machinery is applied to the analysis of a number of problems. Finally, this machinery is applied to the study of fault tolerance in systems of unreliable processors, providing considerable insight into the Byzantine agreement problem, and obtaining improved protocols for Byzantine agreement and many related problems.

  13. Distributed Wind Policy Comparison Tool

    SciTech Connect

    2011-12-01

    Power through Policy: 'Best Practices' for Cost-Effective Distributed Wind is a U.S. Department of Energy (DOE)-funded project to identify distributed wind technology policy best practices and to help policymakers, utilities, advocates, and consumers examine their effectiveness using a pro forma model. Incorporating a customized feed from the Database of State Incentives for Renewables and Efficiency (DSIRE), the Web-based Distributed Wind Policy Comparison Tool (Policy Tool) is designed to assist state, local, and utility officials in understanding the financial impacts of different policy options to help reduce the cost of distributed wind technologies. The Policy Tool can be used to evaluate the ways that a variety of federal and state policies and incentives impact the economics of distributed wind (and subsequently its expected market growth). It also allows policymakers to determine the impact of policy options, addressing market challenges identified in the U.S. DOE’s '20% Wind Energy by 2030' report and helping to meet COE targets.

  14. Size distribution of ring polymers

    PubMed Central

    Medalion, Shlomi; Aghion, Erez; Meirovitch, Hagai; Barkai, Eli; Kessler, David A.

    2016-01-01

    We present an exact solution for the distribution of sample averaged monomer to monomer distance of ring polymers. For non-interacting and local-interaction models these distributions correspond to the distribution of the area under the reflected Bessel bridge and the Bessel excursion respectively, and are shown to be identical in dimension d ≥ 2, albeit with pronounced finite size effects at the critical dimension, d = 2. A symmetry of the problem reveals that dimension d and 4 − d are equivalent, thus the celebrated Airy distribution describing the areal distribution of the d = 1 Brownian excursion describes also a polymer in three dimensions. For a self-avoiding polymer in dimension d we find numerically that the fluctuations of the scaled averaged distance are nearly identical in dimension d = 2, 3 and are well described to a first approximation by the non-interacting excursion model in dimension 5. PMID:27302596

  15. Distributed resource management: garbage collection

    SciTech Connect

    Bagherzadeh, N.

    1987-01-01

    In recent years, there has been a great interest in designing high-performance distributed symbolic-processing computers. These architectures have special needs for resource management and dynamic reclamation of unused memory cells and objects. The memory management or garbage-collection aspects of these architectures are studied. Also introduced is a synchronous distributed algorithm for garbage collection. A special data structure is defined to handle the distributed nature of the problem. The author formally expresses the algorithm and shows the results of a synchronous garbage-collection simulation and its effect on the interconnection-network message to traffic. He presents an asynchronous distributed garbage collection to handle the resource management for a system that does not require a global synchronization mechanism. The distributed data structure is modified to include the asynchronous aspects of the algorithm. This method is extended to a multiple-mutator scheme, and the problem of having several processors share portion of a cyclical graph is discussed. Two models for the analytical study of the garbage-collection algorithms discussed are provided.

  16. Size distribution of ring polymers.

    PubMed

    Medalion, Shlomi; Aghion, Erez; Meirovitch, Hagai; Barkai, Eli; Kessler, David A

    2016-01-01

    We present an exact solution for the distribution of sample averaged monomer to monomer distance of ring polymers. For non-interacting and local-interaction models these distributions correspond to the distribution of the area under the reflected Bessel bridge and the Bessel excursion respectively, and are shown to be identical in dimension d ≥ 2, albeit with pronounced finite size effects at the critical dimension, d = 2. A symmetry of the problem reveals that dimension d and 4 - d are equivalent, thus the celebrated Airy distribution describing the areal distribution of the d = 1 Brownian excursion describes also a polymer in three dimensions. For a self-avoiding polymer in dimension d we find numerically that the fluctuations of the scaled averaged distance are nearly identical in dimension d = 2, 3 and are well described to a first approximation by the non-interacting excursion model in dimension 5. PMID:27302596

  17. Integrated Transmission and Distribution Control

    SciTech Connect

    Kalsi, Karanjit; Fuller, Jason C.; Tuffner, Francis K.; Lian, Jianming; Zhang, Wei; Marinovici, Laurentiu D.; Fisher, Andrew R.; Chassin, Forrest S.; Hauer, Matthew L.

    2013-01-16

    Distributed, generation, demand response, distributed storage, smart appliances, electric vehicles and renewable energy resources are expected to play a key part in the transformation of the American power system. Control, coordination and compensation of these smart grid assets are inherently interlinked. Advanced control strategies to warrant large-scale penetration of distributed smart grid assets do not currently exist. While many of the smart grid technologies proposed involve assets being deployed at the distribution level, most of the significant benefits accrue at the transmission level. The development of advanced smart grid simulation tools, such as GridLAB-D, has led to a dramatic improvement in the models of smart grid assets available for design and evaluation of smart grid technology. However, one of the main challenges to quantifying the benefits of smart grid assets at the transmission level is the lack of tools and framework for integrating transmission and distribution technologies into a single simulation environment. Furthermore, given the size and complexity of the distribution system, it is crucial to be able to represent the behavior of distributed smart grid assets using reduced-order controllable models and to analyze their impacts on the bulk power system in terms of stability and reliability. The objectives of the project were to: • Develop a simulation environment for integrating transmission and distribution control, • Construct reduced-order controllable models for smart grid assets at the distribution level, • Design and validate closed-loop control strategies for distributed smart grid assets, and • Demonstrate impact of integrating thousands of smart grid assets under closed-loop control demand response strategies on the transmission system. More specifically, GridLAB-D, a distribution system tool, and PowerWorld, a transmission planning tool, are integrated into a single simulation environment. The integrated environment

  18. Phenomenology of preequilibrium angular distributions

    SciTech Connect

    Kalbach, C.; Mann, F.M.

    1980-05-01

    The systematics of continuum angular distributions from a wide variety of light ion nuclear reactions have been studied. To first order, the shape of the angular distributions have been found to depend only on the energy of the outgoing particle and on the division of the cross section into multi-step direct and multi-step compound parts. The angular distributions can be described in terms of Legendre polynomials with the reduced polynomial coefficients exhibiting a simple dependence on the outgoing particle energy. Two integer and four continuous parameters with universal values are needed to describe the coefficients for outgoing energies of 2 to 60 MeV in all the reaction types studied. This parameterization combined with a modified Griffin model computer code permits the calculation of double differential cross sections for light ion continuum reactions where no data is available.

  19. Oceanic Satellite Data Distribution System

    NASA Technical Reports Server (NTRS)

    Montgomery, D. R.

    1980-01-01

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

  20. Distributed semantic networks and CLIPS

    NASA Technical Reports Server (NTRS)

    Snyder, James; Rodriguez, Tony

    1991-01-01

    Semantic networks of frames are commonly used as a method of reasoning in many problems. In most of these applications the semantic network exists as a single entity in a single process environment. Advances in workstation hardware provide support for more sophisticated applications involving multiple processes, interacting in a distributed environment. In these applications the semantic network may well be distributed over several concurrently executing tasks. This paper describes the design and implementation of a frame based, distributed semantic network in which frames are accessed both through C Language Integrated Production System (CLIPS) expert systems and procedural C++ language programs. The application area is a knowledge based, cooperative decision making model utilizing both rule based and procedural experts.

  1. What makes distributed practice effective?

    PubMed Central

    Benjamin, Aaron S.; Tullis, Jonathan

    2010-01-01

    The advantages provided to memory by the distribution of multiple practice or study opportunities are among the most powerful effects in memory research. In this paper, we critically review the class of theories that presume contextual or encoding variability as the sole basis for the advantages of distributed practice, and recommend an alternative approach based on the idea that some study events remind learners of other study events. Encoding variability theory encounters serious challenges in two important phenomena that we review here: superadditivity and nonmonotonicity. The bottleneck in such theories lies in the assumption that mnemonic benefits arise from the increasing independence, rather than interdependence, of study opportunities. The reminding model accounts for many basic results in the literature on distributed practice, readily handles data that are problematic for encoding variability theories, including superadditivity and nonmonotonicity, and provides a unified theoretical framework for understanding the effects of repetition and the effects of associative relationships on memory. PMID:20580350

  2. Maintaining consistency in distributed systems

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1991-01-01

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

  3. Modern Messaging for Distributed Sytems

    NASA Astrophysics Data System (ADS)

    Magnoni, L.

    2015-05-01

    Modern software applications rarely live in isolation and nowadays it is common practice to rely on services or consume information provided by remote entities. In such a distributed architecture, integration is key. Messaging, for more than a decade, is the reference solution to tackle challenges of a distributed nature, such as network unreliability, strong-coupling of producers and consumers and the heterogeneity of applications. Thanks to a strong community and a common effort towards standards and consolidation, message brokers are today the transport layer building blocks in many projects and services, both within the physics community and outside. Moreover, in recent years, a new generation of messaging services has appeared, with a focus on low-latency and high-performance use cases, pushing the boundaries of messaging applications. This paper will present messaging solutions for distributed applications going through an overview of the main concepts, technologies and services.

  4. Distributed phased array architecture study

    NASA Technical Reports Server (NTRS)

    Bourgeois, Brian

    1987-01-01

    Variations in amplifiers and phase shifters can cause degraded antenna performance, depending also on the environmental conditions and antenna array architecture. The implementation of distributed phased array hardware was studied with the aid of the DISTAR computer program as a simulation tool. This simulation provides guidance in hardware simulation. Both hard and soft failures of the amplifiers in the T/R modules are modeled. Hard failures are catastrophic: no power is transmitted to the antenna elements. Noncatastrophic or soft failures are modeled as a modified Gaussian distribution. The resulting amplitude characteristics then determine the array excitation coefficients. The phase characteristics take on a uniform distribution. Pattern characteristics such as antenna gain, half power beamwidth, mainbeam phase errors, sidelobe levels, and beam pointing errors were studied as functions of amplifier and phase shifter variations. General specifications for amplifier and phase shifter tolerances in various architecture configurations for C band and S band were determined.

  5. Distributional Cost-Effectiveness Analysis

    PubMed Central

    Asaria, Miqdad; Griffin, Susan; Cookson, Richard

    2015-01-01

    Distributional cost-effectiveness analysis (DCEA) is a framework for incorporating health inequality concerns into the economic evaluation of health sector interventions. In this tutorial, we describe the technical details of how to conduct DCEA, using an illustrative example comparing alternative ways of implementing the National Health Service (NHS) Bowel Cancer Screening Programme (BCSP). The 2 key stages in DCEA are 1) modeling social distributions of health associated with different interventions, and 2) evaluating social distributions of health with respect to the dual objectives of improving total population health and reducing unfair health inequality. As well as describing the technical methods used, we also identify the data requirements and the social value judgments that have to be made. Finally, we demonstrate the use of sensitivity analyses to explore the impacts of alternative modeling assumptions and social value judgments. PMID:25908564

  6. Distributed systems status and control

    NASA Technical Reports Server (NTRS)

    Kreidler, David; Vickers, David

    1990-01-01

    Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

  7. Distributed Scheduling Extension on Hadoop

    NASA Astrophysics Data System (ADS)

    Dadan, Zeng; Xieqin, Wang; Ningkang, Jiang

    Distributed computing splits a large-scale job into multiple tasks and deals with them on clusters. Cluster resource allocation is the key point to restrict the efficiency of distributed computing platform. Hadoop is the current most popular open-source distributed platform. However, the existing scheduling strategies in Hadoop are kind of simple and cannot meet the needs such as sharing the cluster for multi-user, ensuring a concept of guaranteed capacity for each job, as well as providing good performance for interactive jobs. This paper researches the existing scheduling strategies, analyses the inadequacy and adds three new features in Hadoop which can raise the weight of job temporarily, grab cluster resources by higher-priority jobs and support the computing resources share among multi-user. Experiments show they can help in providing better performance for interactive jobs, as well as more fairly share of computing time among users.

  8. Shape of Pion Distribution Amplitude

    SciTech Connect

    Radyushkin, Anatoly

    2009-11-01

    A scenario is investigated in which the leading-twist pion distribution amplitude $\\varphi_\\pi (x)$ is approximated by the pion decay constant $f_\\pi$ for all essential values of the light-cone fraction $x$. A model for the light-front wave function $\\Psi (x, k_\\perp)$ is proposed that produces such a distribution amplitude and has a rapidly decreasing (exponential for definiteness) dependence on the light-front energy combination $ k_\\perp^2/x(1-x)$. It is shown that this model easily reproduces the fit of recent large-$Q^2$ BaBar data on the photon-pion transition form factor. Some aspects of scenario with flat pion distribution amplitude are discussed.

  9. How robust are distributed systems

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1989-01-01

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

  10. Overdispersion: Notes on discrete distributions

    SciTech Connect

    Bowman, K.O.; Shenton, L.R.; Kastenbaum, M.A.; Broman, K.

    1992-09-01

    We introduce mixtures of binomial distributions derived by assuming that the probability parameter p varies according to some law. We use the transformation p = exp({minus}t) and consider various appropriate densities for the transformed variables. In the process, the Laplace transform becomes the fundamental entity. Large numbers of new binomial mixtures are generated in this way. Some transformations may involve several variates that lead to ``multivariate`` binomial mixtures. An extension of this to the logarithmic distribution, with parameter p, is possible. Frullani integrals and Laplace transforms are encountered. Graphical representations of some of the more significant distributions are given. These include probability functions, regions of validity, and three dimensional representations of probability functions showing the response to variation of parameters when two parameters are involved.

  11. Overdispersion: Notes on discrete distributions

    SciTech Connect

    Bowman, K.O. ); Shenton, L.R. ); Kastenbaum, M.A. ); Broman, K. )

    1992-09-01

    We introduce mixtures of binomial distributions derived by assuming that the probability parameter p varies according to some law. We use the transformation p = exp([minus]t) and consider various appropriate densities for the transformed variables. In the process, the Laplace transform becomes the fundamental entity. Large numbers of new binomial mixtures are generated in this way. Some transformations may involve several variates that lead to multivariate'' binomial mixtures. An extension of this to the logarithmic distribution, with parameter p, is possible. Frullani integrals and Laplace transforms are encountered. Graphical representations of some of the more significant distributions are given. These include probability functions, regions of validity, and three dimensional representations of probability functions showing the response to variation of parameters when two parameters are involved.

  12. Hydronic distribution system computer model

    SciTech Connect

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

    1994-10-01

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

  13. Distribution Metrics and Image Segmentation

    PubMed Central

    Georgiou, Tryphon; Michailovich, Oleg; Rathi, Yogesh; Malcolm, James; Tannenbaum, Allen

    2007-01-01

    The purpose of this paper is to describe certain alternative metrics for quantifying distances between distributions, and to explain their use and relevance in visual tracking. Besides the theoretical interest, such metrics may be used to design filters for image segmentation, that is for solving the key visual task of separating an object from the background in an image. The segmenting curve is represented as the zero level set of a signed distance function. Most existing methods in the geometric active contour framework perform segmentation by maximizing the separation of intensity moments between the interior and the exterior of an evolving contour. Here one can use the given distributional metric to determine a flow which minimizes changes in the distribution inside and outside the curve. PMID:18769529

  14. Distributive Marketing Education: Innovative Instructional Techniques in Distributive Marketing Education.

    ERIC Educational Resources Information Center

    Office of Education (DHEW), Washington, DC.

    The conference featured more than 40 presentations representing existing and planned innovative programs in all levels of distributive marketing education in six States. In addition to the presentations (not reproduced in their entirety in the report), there were sessions and workshops for secondary, post secondary, and adult levels and for city…

  15. CUMPOIS- CUMULATIVE POISSON DISTRIBUTION PROGRAM

    NASA Technical Reports Server (NTRS)

    Bowerman, P. N.

    1994-01-01

    The Cumulative Poisson distribution program, CUMPOIS, is one of two programs which make calculations involving cumulative poisson distributions. Both programs, CUMPOIS (NPO-17714) and NEWTPOIS (NPO-17715), can be used independently of one another. CUMPOIS determines the approximate cumulative binomial distribution, evaluates the cumulative distribution function (cdf) for gamma distributions with integer shape parameters, and evaluates the cdf for chi-square distributions with even degrees of freedom. It can be used by statisticians and others concerned with probabilities of independent events occurring over specific units of time, area, or volume. CUMPOIS calculates the probability that n or less events (ie. cumulative) will occur within any unit when the expected number of events is given as lambda. Normally, this probability is calculated by a direct summation, from i=0 to n, of terms involving the exponential function, lambda, and inverse factorials. This approach, however, eventually fails due to underflow for sufficiently large values of n. Additionally, when the exponential term is moved outside of the summation for simplification purposes, there is a risk that the terms remaining within the summation, and the summation itself, will overflow for certain values of i and lambda. CUMPOIS eliminates these possibilities by multiplying an additional exponential factor into the summation terms and the partial sum whenever overflow/underflow situations threaten. The reciprocal of this term is then multiplied into the completed sum giving the cumulative probability. The CUMPOIS program is written in C. It was developed on an IBM AT with a numeric co-processor using Microsoft C 5.0. Because the source code is written using standard C structures and functions, it should compile correctly on most C compilers. The program format is interactive, accepting lambda and n as inputs. It has been implemented under DOS 3.2 and has a memory requirement of 26K. CUMPOIS was

  16. Cloud Distribution Statistics from LITE

    NASA Technical Reports Server (NTRS)

    Winker, David M.

    1998-01-01

    The Lidar In-Space Technology Experiment (LITE) mission has demonstrated the utility of spaceborne lidar in observing multilayer clouds and has provided a dataset showing the distribution of tropospheric clouds and aerosols. These unambiguous observations of the vertical distribution of clouds will allow improved verification of current cloud climatologies and GCM cloud parameterizations. Although there is now great interest in cloud profiling radar, operating in the mm-wave region, for the spacebased observation of cloud heights the results of the LITE mission have shown that satellite lidars can also make significant contributions in this area.

  17. SINGULARITIES OF GENERALIZED PARTON DISTRIBUTIONS

    SciTech Connect

    Anatoly Radyushkin

    2012-12-01

    We discuss recent developments in building models for generalized parton distributions (GPDs) that are based on the formalism of double distributions (DDs). A special attention is given to a careful analysis of the singularity structure of DDs. The DD formalism is applied to construction of a model GPDs with a singular Regge behavior. Within the developed DD-based approach, we discuss the structure of GPD sum rules. It is shown that separation of DDs into the so-called ``plus'' part and the D-term part may be treated as a renormalization procedure for the GPD sum rules. This approach is compared with an alternative prescription based on analytic regularization.

  18. Shared versus distributed memory multiprocessors

    NASA Technical Reports Server (NTRS)

    Jordan, Harry F.

    1991-01-01

    The question of whether multiprocessors should have shared or distributed memory has attracted a great deal of attention. Some researchers argue strongly for building distributed memory machines, while others argue just as strongly for programming shared memory multiprocessors. A great deal of research is underway on both types of parallel systems. Special emphasis is placed on systems with a very large number of processors for computation intensive tasks and considers research and implementation trends. It appears that the two types of systems will likely converge to a common form for large scale multiprocessors.

  19. Medium Effects in Parton Distributions

    SciTech Connect

    William Detmold, Huey-Wen Lin

    2011-12-01

    A defining experiment of high-energy physics in the 1980s was that of the EMC collaboration where it was first observed that parton distributions in nuclei are non-trivially related to those in the proton. This result implies that the presence of the nuclear medium plays an important role and an understanding of this from QCD has been an important goal ever since Here we investigate analogous, but technically simpler, effects in QCD and examine how the lowest moment of the pion parton distribution is modified by the presence of a Bose-condensed gas of pions or kaons.

  20. Distributional preferences and competitive behavior☆

    PubMed Central

    Balafoutas, Loukas; Kerschbamer, Rudolf; Sutter, Matthias

    2012-01-01

    We study experimentally the relationship between distributional preferences and competitive behavior. We find that spiteful subjects react strongest to competitive pressure and win in a tournament significantly more often than efficiency-minded and inequality averse subjects. However, when given the choice between a tournament and a piece rate scheme, efficiency-minded subjects choose the tournament most often, while spiteful and inequality averse subjects avoid it. When controlling for distributional preferences, risk attitudes and past performance, the gender gap in the willingness to compete is no longer significant, indicating that gender-related variables explain why twice as many men as women self-select into competition. PMID:23576829

  1. Modeling Nucleon Generalized Parton Distributions

    SciTech Connect

    Radyushkin, Anatoly V.

    2013-05-01

    We discuss building models for nucleon generalized parton distributions (GPDs) H and E that are based on the formalism of double distributions (DDs). We found that the usual "DD+D-term" construction should be amended by an extra term, xiE^1_+ (x,xi) built from the alpha/Beta moment of the DD e(Beta,alpha) that generates GPD E(x,xi). Unlike the D-term, this function has support in the whole -1< x<1 region, and in general does not vanish at the border points |x|=xi.

  2. Standard Distributions: One Graph Fits All

    ERIC Educational Resources Information Center

    Wagner, Clifford H.

    2007-01-01

    Standard distributions are ubiquitous but not unique. With suitable scaling, the graph of a standard distribution serves as the graph for every distribution in the family. The standard exponential can easily be taught in elementary statistics courses.

  3. Are quasar redshifts randomly distributed

    NASA Technical Reports Server (NTRS)

    Weymann, R. J.; Boroson, T.; Scargle, J. D.

    1978-01-01

    A statistical analysis of possible clumping (not periodicity) of emission line redshifts of QSO's shows the available data to be compatible with random fluctuations of a smooth, non-clumped distribution. This result is demonstrated with Monte Carlo simulations as well as with the Kolmogorov-Smirnov test. It is in complete disagreement with the analysis by Varshni, which is shown to be incorrect.

  4. 76 FR 42768 - Capital Distribution

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ... Office of Thrift Supervision Capital Distribution AGENCY: Office of Thrift Supervision (OTS), Treasury... Reduction Act of 1995, 44 U.S.C. 3507. The Office of Thrift Supervision within the Department of the... Thrift Supervision, 1700 G Street, NW., Washington, DC 20552. FOR FURTHER INFORMATION CONTACT: You...

  5. Distributed user services for supercomputers

    NASA Technical Reports Server (NTRS)

    Sowizral, Henry A.

    1989-01-01

    User-service operations at supercomputer facilities are examined. The question is whether a single, possibly distributed, user-services organization could be shared by NASA's supercomputer sites in support of a diverse, geographically dispersed, user community. A possible structure for such an organization is identified as well as some of the technologies needed in operating such an organization.

  6. Distributed Leadership: Democracy or Delivery?

    ERIC Educational Resources Information Center

    Hargreaves, Andy; Fink, Dean

    2008-01-01

    Purpose: This article aims to discusses the nature and benefits of lateral approaches to educational change, especially in the form of distributed leadership, that treat schools, localities, states, or nations, as "living systems" interconnected by mutual influence. Design/methodology/approach: The paper presents a conceptual discussion of the…

  7. A distributed telerobotics construction set

    NASA Technical Reports Server (NTRS)

    Wise, James D.

    1994-01-01

    During the course of our research on distributed telerobotic systems, we have assembled a collection of generic, reusable software modules and an infrastructure for connecting them to form a variety of telerobotic configurations. This paper describes the structure of this 'Telerobotics Construction Set' and lists some of the components which comprise it.

  8. Career Information: Marketing and Distribution.

    ERIC Educational Resources Information Center

    American Vocational Association, Inc., Washington, DC.

    The publication is a bibliography prepared in an attempt to assist guidance and distributive education personnel in their task of securing relevant published career information. Depending on overall adequacy, three categories of the National Vocational Guidance Association (NVGA)--highly recommended, recommended, and useful--were used in rating…

  9. Tools for distributed application management

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Wood, Mark; Cooper, Robert; Birman, Kenneth P.

    1990-01-01

    Distributed application management consists of monitoring and controlling an application as it executes in a distributed environment. It encompasses such activities as configuration, initialization, performance monitoring, resource scheduling, and failure response. The Meta system is described: a collection of tools for constructing distributed application management software. Meta provides the mechanism, while the programmer specifies the policy for application management. The policy is manifested as a control program which is a soft real time reactive program. The underlying application is instrumented with a variety of built-in and user defined sensors and actuators. These define the interface between the control program and the application. The control program also has access to a database describing the structure of the application and the characteristics of its environment. Some of the more difficult problems for application management occur when pre-existing, nondistributed programs are integrated into a distributed application for which they may not have been intended. Meta allows management functions to be retrofitted to such programs with a minimum of effort.

  10. Tools for distributed application management

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Cooper, Robert; Wood, Mark; Birman, Kenneth P.

    1990-01-01

    Distributed application management consists of monitoring and controlling an application as it executes in a distributed environment. It encompasses such activities as configuration, initialization, performance monitoring, resource scheduling, and failure response. The Meta system (a collection of tools for constructing distributed application management software) is described. Meta provides the mechanism, while the programmer specifies the policy for application management. The policy is manifested as a control program which is a soft real-time reactive program. The underlying application is instrumented with a variety of built-in and user-defined sensors and actuators. These define the interface between the control program and the application. The control program also has access to a database describing the structure of the application and the characteristics of its environment. Some of the more difficult problems for application management occur when preexisting, nondistributed programs are integrated into a distributed application for which they may not have been intended. Meta allows management functions to be retrofitted to such programs with a minimum of effort.

  11. Distributed Leadership in Educational Institutions

    ERIC Educational Resources Information Center

    Göksoy, Süleyman

    2015-01-01

    In recent years, many studies are conducted about shared leadership process. Distributed leadership (DL) approach addresses leadership along with teams, groups and organizational characteristics. In practice, this approach objects the supposition that an individual should take the lead in order to ensure change. Proponents of this idea claim that…

  12. Parallel, Distributed Scripting with Python

    SciTech Connect

    Miller, P J

    2002-05-24

    Parallel computers used to be, for the most part, one-of-a-kind systems which were extremely difficult to program portably. With SMP architectures, the advent of the POSIX thread API and OpenMP gave developers ways to portably exploit on-the-box shared memory parallelism. Since these architectures didn't scale cost-effectively, distributed memory clusters were developed. The associated MPI message passing libraries gave these systems a portable paradigm too. Having programmers effectively use this paradigm is a somewhat different question. Distributed data has to be explicitly transported via the messaging system in order for it to be useful. In high level languages, the MPI library gives access to data distribution routines in C, C++, and FORTRAN. But we need more than that. Many reasonable and common tasks are best done in (or as extensions to) scripting languages. Consider sysadm tools such as password crackers, file purgers, etc ... These are simple to write in a scripting language such as Python (an open source, portable, and freely available interpreter). But these tasks beg to be done in parallel. Consider the a password checker that checks an encrypted password against a 25,000 word dictionary. This can take around 10 seconds in Python (6 seconds in C). It is trivial to parallelize if you can distribute the information and co-ordinate the work.

  13. Distributed Learning and Institutional Restructuring.

    ERIC Educational Resources Information Center

    Hawkins, Brian L.

    1999-01-01

    Discusses the following challenges institutions must consider as they enter the new marketplace of distributed learning: library access, faculty workload, faculty incentives, faculty-support structures, intellectual property, articulation agreements, financial aid, pricing, cross-subsidization of programs, institutional loyalty and philanthropy,…

  14. Requiring Collaboration or Distributing Leadership?

    ERIC Educational Resources Information Center

    Kennedy, Anne; Deuel, Angie; Nelson, Tamara Holmlund; Slavit, David

    2011-01-01

    Through the process of initiating, implementing, and sustaining a schoolwide professional learning community (PLC), teachers and administrators at the pseudonymous Silver Valley Middle School provide a powerful example of distributed leadership in action. New leadership roles, coordination, and interdependency among staff have led to an increased…

  15. Educational Micropolitics and Distributed Leadership

    ERIC Educational Resources Information Center

    Flessa, Joseph

    2009-01-01

    This article critically reviews two bodies of literature that potentially share common concerns, yet rarely overlap: distributed leadership and educational micropolitics. Alternative explanations for the split between these two analytical approaches to school organization are explored in sections on problem framing, methodology, and the…

  16. Size distribution of detached drops

    NASA Astrophysics Data System (ADS)

    Baluev, V. V.; Stepanov, V. M.

    1989-10-01

    The law governing the size distribution of detached gas-liquid streams of drops has been determined analytically, and a comparison is carried out against experimental data existing in the literature. The derived theoretical relationships offer an excellent description of existing experimental results.

  17. Bug Distribution and Pattern Classification.

    ERIC Educational Resources Information Center

    Tatsuoka, Kikumi K.; Tatsuoka, Maurice M.

    The study examines the rule space model, a probabilistic model capable of measuring cognitive skill acquisition and of diagnosing erroneous rules of operation in a procedural domain. The model involves two important components: (1) determination of a set of bug distributions (bug density functions representing clusters around the rules); and (2)…

  18. Modeling Natural Variation through Distribution

    ERIC Educational Resources Information Center

    Lehrer, Richard; Schauble, Leona

    2004-01-01

    This design study tracks the development of student thinking about natural variation as late elementary grade students learned about distribution in the context of modeling plant growth at the population level. The data-modeling approach assisted children in coordinating their understanding of particular cases with an evolving notion of data as an…

  19. Prior Distributions on Symmetric Groups

    ERIC Educational Resources Information Center

    Gupta, Jayanti; Damien, Paul

    2005-01-01

    Fully and partially ranked data arise in a variety of contexts. From a Bayesian perspective, attention has focused on distance-based models; in particular, the Mallows model and extensions thereof. In this paper, a class of prior distributions, the "Binary Tree," is developed on the symmetric group. The attractive features of the class are: it…

  20. Is Creative Thinking Normally Distributed?

    ERIC Educational Resources Information Center

    Wakefield, John F.

    The hypothesis of positive skew in distributions of response to creative thinking tasks was studied. Data were obtained from examinees' responses to problem-solving tasks in three published studies of creative thinking. Subjects included 23 fifth graders (12 females and 11 males), 29 high school students (10 females and 19 males), and 47 female…

  1. Cooperative distributed architecture for mashups

    NASA Astrophysics Data System (ADS)

    Al-Haj Hassan, Osama Mohammad; Ramaswamy, Lakshmish; Hamad, Fadi; Abu Taleb, Anas

    2014-05-01

    Since the advent of Web 2.0, personalised applications such as mashups have become widely popular. Mashups enable end-users to fetch data from distributed data sources, and refine it based on their personal needs. This high degree of personalisation that mashups offer comes at the expense of performance and scalability. These scalability challenges are exacerbated by the centralised architectures of current mashup platforms. In this paper, we address the performance and scalability issues by designing CoMaP - a distributed mashup platform. CoMaP's architecture comprises of several cooperative mashup processing nodes distributed over the Internet upon which mashups can, fully or partially, be executed. CoMaP incorporates a dynamic and efficient scheme for deploying mashups on the processing nodes. Our scheme considers a number of parameters such as variations in link delays and bandwidths, and loads on mashup processing nodes. CoMaP includes effective and low-cost mechanisms for balancing loads on the processing nodes as well for handling node failures. Furthermore, we propose novel techniques that leverage keyword synonyms, ontologies and caching to enhance end-user experience. This paper reports several experiments to comprehensively study CoMaP's performance. The results demonstrate CoMaP's benefits as a scalable distributed mashup platform.

  2. Random distributed feedback fibre lasers

    NASA Astrophysics Data System (ADS)

    Turitsyn, Sergei K.; Babin, Sergey A.; Churkin, Dmitry V.; Vatnik, Ilya D.; Nikulin, Maxim; Podivilov, Evgenii V.

    2014-09-01

    The concept of random lasers exploiting multiple scattering of photons in an amplifying disordered medium in order to generate coherent light without a traditional laser resonator has attracted a great deal of attention in recent years. This research area lies at the interface of the fundamental theory of disordered systems and laser science. The idea was originally proposed in the context of astrophysics in the 1960s by V.S. Letokhov, who studied scattering with “negative absorption” of the interstellar molecular clouds. Research on random lasers has since developed into a mature experimental and theoretical field. A simple design of such lasers would be promising for potential applications. However, in traditional random lasers the properties of the output radiation are typically characterized by complex features in the spatial, spectral and time domains, making them less attractive than standard laser systems in terms of practical applications. Recently, an interesting and novel type of one-dimensional random laser that operates in a conventional telecommunication fibre without any pre-designed resonator mirrors-random distributed feedback fibre laser-was demonstrated. The positive feedback required for laser generation in random fibre lasers is provided by the Rayleigh scattering from the inhomogeneities of the refractive index that are naturally present in silica glass. In the proposed laser concept, the randomly backscattered light is amplified through the Raman effect, providing distributed gain over distances up to 100 km. Although an effective reflection due to the Rayleigh scattering is extremely small (˜0.1%), the lasing threshold may be exceeded when a sufficiently large distributed Raman gain is provided. Such a random distributed feedback fibre laser has a number of interesting and attractive features. The fibre waveguide geometry provides transverse confinement, and effectively one-dimensional random distributed feedback leads to the generation

  3. The neutron star mass distribution

    SciTech Connect

    Kiziltan, Bülent; Kottas, Athanasios; De Yoreo, Maria; Thorsett, Stephen E.

    2013-11-20

    In recent years, the number of pulsars with secure mass measurements has increased to a level that allows us to probe the underlying neutron star (NS) mass distribution in detail. We critically review the radio pulsar mass measurements. For the first time, we are able to analyze a sizable population of NSs with a flexible modeling approach that can effectively accommodate a skewed underlying distribution and asymmetric measurement errors. We find that NSs that have evolved through different evolutionary paths reflect distinctive signatures through dissimilar distribution peak and mass cutoff values. NSs in double NS and NS-white dwarf (WD) systems show consistent respective peaks at 1.33 M {sub ☉} and 1.55 M {sub ☉}, suggesting significant mass accretion (Δm ≈ 0.22 M {sub ☉}) has occurred during the spin-up phase. The width of the mass distribution implied by double NS systems is indicative of a tight initial mass function while the inferred mass range is significantly wider for NSs that have gone through recycling. We find a mass cutoff at ∼2.1 M {sub ☉} for NSs with WD companions, which establishes a firm lower bound for the maximum NS mass. This rules out the majority of strange quark and soft equation of state models as viable configurations for NS matter. The lack of truncation close to the maximum mass cutoff along with the skewed nature of the inferred mass distribution both enforce the suggestion that the 2.1 M {sub ☉} limit is set by evolutionary constraints rather than nuclear physics or general relativity, and the existence of rare supermassive NSs is possible.

  4. Centaur size distribution with DECam

    NASA Astrophysics Data System (ADS)

    Fuentes, Cesar; Trilling, David E.; Schlichting, Hilke

    2014-11-01

    We present the results of the 2014 centaur search campaign on the Dark Energy Camera (DECam) in Tololo, Chile. This is the largest debiased Centaur survey to date, measuring for the first time the size distribution of small Centaurs (1-10km) and the first time the sizes of planetesimals from which the entire Solar System formed are directly detected.The theoretical model for the coagulation and collisional evolution of the outer solar system proposed in Schlichting et al. 2013 predicts a steep rise in the size distribution of TNOs smaller than 10km. These objects are below the detection limit of current TNO surveys but feasible for the Centaur population. By constraining the number of Centaurs and this feature in their size distribution we can confirm the collisional evolution of the Solar System and estimate the rate at which material is being transferred from the outer to the inner Solar System. If the shallow power law behavior from the TNO size distribution at ~40km can be extrapolated to 1km, the size of the Jupiter Family of Comets (JFC), there would not be enough small TNOs to supply the JFC population (Volk & Malhotra, 2008), debunking the link between TNOs and JFCs.We also obtain the colors of small Centaurs and TNOs, providing a signature of collisional evolution by measuring if there is in fact a relationship between color and size. If objects smaller than the break in the TNO size distribution are being ground down by collisions then their surfaces should be fresh, and then appear bluer in the optical than larger TNOs that are not experiencing collisions.

  5. Distributed data analysis in ATLAS

    NASA Astrophysics Data System (ADS)

    Nilsson, Paul; Atlas Collaboration

    2012-12-01

    Data analysis using grid resources is one of the fundamental challenges to be addressed before the start of LHC data taking. The ATLAS detector will produce petabytes of data per year, and roughly one thousand users will need to run physics analyses on this data. Appropriate user interfaces and helper applications have been made available to ensure that the grid resources can be used without requiring expertise in grid technology. These tools enlarge the number of grid users from a few production administrators to potentially all participating physicists. ATLAS makes use of three grid infrastructures for the distributed analysis: the EGEE sites, the Open Science Grid, and Nordu Grid. These grids are managed by the gLite workload management system, the PanDA workload management system, and ARC middleware; many sites can be accessed via both the gLite WMS and PanDA. Users can choose between two front-end tools to access the distributed resources. Ganga is a tool co-developed with LHCb to provide a common interface to the multitude of execution backends (local, batch, and grid). The PanDA workload management system provides a set of utilities called PanDA Client; with these tools users can easily submit Athena analysis jobs to the PanDA-managed resources. Distributed data is managed by Don Quixote 2, a system developed by ATLAS; DQ2 is used to replicate datasets according to the data distribution policies and maintains a central catalog of file locations. The operation of the grid resources is continually monitored by the Ganga Robot functional testing system, and infrequent site stress tests are performed using the Hammer Cloud system. In addition, the DAST shift team is a group of power users who take shifts to provide distributed analysis user support; this team has effectively relieved the burden of support from the developers.

  6. Gaussian Velocity Distributions in Avalanches

    NASA Astrophysics Data System (ADS)

    Shattuck, Mark

    2004-03-01

    Imagine a world where gravity is so strong that if an ice cube is tilted the shear forces melt the surface and water avalanches down. Further imagine that the ambient temperature is so low that the water re-freezes almost immediately. This is the world of granular flows. As a granular solid is tilted the surface undergoes a sublimation phase transition and a granular gas avalanches down the surface, but the inelastic collisions rapidly remove energy from the flow lowering the granular temperature (kinetic energy per particle) until the gas solidifies again. It is under these extreme conditions that we attempt to uncover continuum granular flow properties. Typical continuum theories like Navier-Stokes equation for fluids follow the space-time evolution of the first few moments of the velocity distribution. We study continuously avalanching flow in a rotating two-dimensional granular drum using high-speed video imaging and extract the position and velocities of the particles. We find a universal near Gaussian velocity distribution throughout the flowing regions, which are characterized by a liquid-like radial distribution function. In the remaining regions, in which the radial distribution function develops sharp crystalline peaks, the velocity distribution has a Gaussian peak but is much broader in the tails. In a companion experiment on a vibrated two-dimensional granular fluid under constant pressure, we find a clear gas-solid phase transition in which both the temperature and density change discontinuously. This suggests that a low temperature crystal and a high temperature gas can coexist in steady state. This coexistence could result in a narrower, cooler, Gaussian peak and a broader, warmer, Gaussian tail like the non-Gaussian behavior seen in the crystalline portions of the rotating drum.

  7. Distributed intelligence in an astronomical Distributed Sensor Network

    NASA Astrophysics Data System (ADS)

    White, R. R.; Davis, H.; Vestrand, W. T.; Wozniak, P. R.

    2008-03-01

    The Telescope Alert Operations Network System (TALONS) was designed and developed in the year 2000, around the architectural principles of a distributed sensor network. This network supported the original Rapid Telescopes for Optical Response (RAPTOR) project goals; however, only with further development could TALONS meet the goals of the larger Thinking Telescope Project. The complex objectives of the Thinking Telescope project required a paradigm shift in the software architecture - the centralised intelligence merged into the TALONS network operations could no longer meet all of the new requirements. The intelligence needed to be divorced from the network operations and developed as a series of peripheral intelligent agents, distributing the decision making and analytical processes based on the temporal volatility of the data. This paper is presented as only one part of the poster from the workshop and in it we will explore the details of this architecture and how that merges with the current Thinking Telescope system to meet our project goals.

  8. A heuristic for efficient data distribution management in distributed simulation

    NASA Astrophysics Data System (ADS)

    Gupta, Pankaj; Guha, Ratan K.

    2005-05-01

    In this paper, we propose an algorithm for reducing the complexity of region matching and efficient multicasting in data distribution management component of High Level Architecture (HLA) Run Time Infrastructure (RTI). The current data distribution management (DDM) techniques rely on computing the intersection between the subscription and update regions. When a subscription region and an update region of different federates overlap, RTI establishes communication between the publisher and the subscriber. It subsequently routes the updates from the publisher to the subscriber. The proposed algorithm computes the update/subscription regions matching for dynamic allocation of multicast group. It provides new multicast routines that exploit the connectivity of federation by communicating updates regarding interactions and routes information only to those federates that require them. The region-matching problem in DDM reduces to clique-covering problem using the connections graph abstraction where the federations represent the vertices and the update/subscribe relations represent the edges. We develop an abstract model based on connection graph for data distribution management. Using this abstract model, we propose a heuristic for solving the region-matching problem of DDM. We also provide complexity analysis of the proposed heuristics.

  9. Mixture of Skewed α-Stable Distributions

    NASA Astrophysics Data System (ADS)

    Shojaei, S. R. Hosseini; Nassiri, V.; Mohammadian, Gh. R.; Mohammadpour, A.

    2011-03-01

    Expectation maximization (EM) algorithm and the Bayesian techniques are two approaches for statistical inference of mixture models [3, 4]. By noting the advantages of the Bayesian methods, practitioners prefer them. However, implementing Markov chain Monte Carlo algorithms can be very complicated for stable distributions, due to the non-analytic density or distribution function formulas. In this paper, we introduce a new class of mixture of heavy-tailed distributions, called mixture of skewed stable distributions. Skewed stable distributions belongs to the exponential family and they have analytic density representation. It is shown that skewed stable distributions dominate skew stable distribution functions and they can be used to model heavy-tailed data. The class of skewed stable distributions has an analytic representation for its density function and the Bayesian inference can be done similar to the exponential family of distributions. Finally, mixture of skewed stable distributions are compared to the mixture of stable distributions through a simulations study.

  10. 26 CFR 1.652(a)-2 - Distributions in excess of distributable net income.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Distributions in excess of distributable net... Only § 1.652(a)-2 Distributions in excess of distributable net income. If the amount of income required to be distributed currently to beneficiaries exceeds the distributable net income of the trust...

  11. Distribution Integrity Management Plant (DIMP)

    SciTech Connect

    Gonzales, Jerome F.

    2012-05-07

    This document is the distribution integrity management plan (Plan) for the Los Alamos National Laboratory (LANL) Natural Gas Distribution System. This Plan meets the requirements of 49 CFR Part 192, Subpart P Distribution Integrity Management Programs (DIMP) for the LANL Natural Gas Distribution System. This Plan was developed by reviewing records and interviewing LANL personnel. The records consist of the design, construction, operation and maintenance for the LANL Natural Gas Distribution System. The records system for the LANL Natural Gas Distribution System is limited, so the majority of information is based on the judgment of LANL employees; the maintenance crew, the Corrosion Specialist and the Utilities and Infrastructure (UI) Civil Team Leader. The records used in this report are: Pipeline and Hazardous Materials Safety Administration (PHMSA) 7100.1-1, Report of Main and Service Line Inspection, Natural Gas Leak Survey, Gas Leak Response Report, Gas Leak and Repair Report, and Pipe-to-Soil Recordings. The specific elements of knowledge of the infrastructure used to evaluate each threat and prioritize risks are listed in Sections 6 and 7, Threat Evaluation and Risk Prioritization respectively. This Plan addresses additional information needed and a method for gaining that data over time through normal activities. The processes used for the initial assessment of Threat Evaluation and Risk Prioritization are the methods found in the Simple, Handy Risk-based Integrity Management Plan (SHRIMP{trademark}) software package developed by the American Pipeline and Gas Agency (APGA) Security and Integrity Foundation (SIF). SHRIMP{trademark} uses an index model developed by the consultants and advisors of the SIF. Threat assessment is performed using questions developed by the Gas Piping Technology Company (GPTC) as modified and added to by the SHRIMP{trademark} advisors. This Plan is required to be reviewed every 5 years to be continually refined and improved. Records

  12. Nation Radiobiology Archives Distributed Access

    SciTech Connect

    Smith, S. K.; Prather, J. C.; Ligotke, E. K.; Watson, C. R.

    1992-06-01

    NRADA1.1 is a supplement to NRADA1.0. This version eliminates several bugs, and includes a few new features. The diskettes consist of a distributed subset of information representative of the extensive NRA databases and database access software maintained at the Pacific Northwest Laboratory which provide an introduction to the scope and style of the NRA Information Systems. Information in the NRA Summary, Inventory, and Bibliographic database is available upon request. Printed reports have been provided in the past. The completion of the NRADA1.1 is the realization of a long standing goal of the staff and advisory committee. Information may be easily distributed to the user in an electronic form which preserves the relationships between the various databases.

  13. Hazards Data Distribution System (HDDS)

    USGS Publications Warehouse

    Jones, Brenda; Lamb, Rynn

    2015-01-01

    When emergencies occur, first responders and disaster response teams often need rapid access to aerial photography and satellite imagery that is acquired before and after the event. The U.S. Geological Survey (USGS) Hazards Data Distribution System (HDDS) provides quick and easy access to pre- and post-event imagery and geospatial datasets that support emergency response and recovery operations. The HDDS provides a single, consolidated point-of-entry and distribution system for USGS-hosted remotely sensed imagery and other geospatial datasets related to an event response. The data delivery services are provided through an interactive map-based interface that allows emergency response personnel to rapidly select and download pre-event ("baseline") and post-event emergency response imagery.

  14. Models for the hotspot distribution

    SciTech Connect

    Jurdy, D.M. ); Stefanick, M. )

    1990-10-01

    Published hotspot catalogues all show a hemispheric concentration beyond what can be expected by chance. Cumulative distributions about the center of concentration are described by a power law with a fractal dimension closer to 1 than 2. Random sets of the corresponding sizes do not show this effect. A simple shift of the random sets away from a point would produce distributions similar to those of hotspot sets. The possible relation of the hotspots to the locations of ridges and subduction zones is tested using large sets of randomly-generated points to estimate areas within given distances of the plate boundaries. The probability of finding the observed number of hotspots within 10 of the ridges is about what is expected.

  15. Nation Radiobiology Archives Distributed Access

    Energy Science and Technology Software Center (ESTSC)

    1992-06-01

    NRADA1.1 is a supplement to NRADA1.0. This version eliminates several bugs, and includes a few new features. The diskettes consist of a distributed subset of information representative of the extensive NRA databases and database access software maintained at the Pacific Northwest Laboratory which provide an introduction to the scope and style of the NRA Information Systems. Information in the NRA Summary, Inventory, and Bibliographic database is available upon request. Printed reports have been provided inmore » the past. The completion of the NRADA1.1 is the realization of a long standing goal of the staff and advisory committee. Information may be easily distributed to the user in an electronic form which preserves the relationships between the various databases.« less

  16. A global distributed storage architecture

    NASA Technical Reports Server (NTRS)

    Lionikis, Nemo M.; Shields, Michael F.

    1996-01-01

    NSA architects and planners have come to realize that to gain the maximum benefit from, and keep pace with, emerging technologies, we must move to a radically different computing architecture. The compute complex of the future will be a distributed heterogeneous environment, where, to a much greater extent than today, network-based services are invoked to obtain resources. Among the rewards of implementing the services-based view are that it insulates the user from much of the complexity of our multi-platform, networked, computer and storage environment and hides its diverse underlying implementation details. In this paper, we will describe one of the fundamental services being built in our envisioned infrastructure; a global, distributed archive with near-real-time access characteristics. Our approach for adapting mass storage services to this infrastructure will become clear as the service is discussed.

  17. Estimators for the Cauchy distribution

    SciTech Connect

    Hanson, K.M.; Wolf, D.R.

    1993-12-31

    We discuss the properties of various estimators of the central position of the Cauchy distribution. The performance of these estimators is evaluated for a set of simulated experiments. Estimators based on the maximum and mean of the posterior probability density function are empirically found to be well behaved when more than two measurements are available. On the contrary, because of the infinite variance of the Cauchy distribution, the average of the measured positions is an extremely poor estimator of the location of the source. However, the median of the measured positions is well behaved. The rms errors for the various estimators are compared to the Fisher-Cramer-Rao lower bound. We find that the square root of the variance of the posterior density function is predictive of the rms error in the mean posterior estimator.

  18. Conformation Distributions in Adsorbed Proteins.

    NASA Astrophysics Data System (ADS)

    Meuse, Curtis W.; Hubbard, Joseph B.; Vrettos, John S.; Smith, Jackson R.; Cicerone, Marcus T.

    2007-03-01

    While the structural basis of protein function is well understood in the biopharmaceutical and biotechnology industries, few methods for the characterization and comparison of protein conformation distributions are available. New methods capable of measuring the stability of protein conformations and the integrity of protein-protein, protein-ligand and protein-surface interactions both in solution and on surfaces are needed to help the development of protein-based products. We are developing infrared spectroscopy methods for the characterization and comparison of molecular conformation distributions in monolayers and in solutions. We have extracted an order parameter describing the orientational and conformational variations of protein functional groups around the average molecular values from a single polarized spectrum. We will discuss the development of these methods and compare them to amide hydrogen/deuterium exchange methods for albumin in solution and on different polymer surfaces to show that our order parameter is related to protein stability.

  19. Distributed antenna system and method

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  20. Antenna structure with distributed strip

    SciTech Connect

    Rodenbeck, Christopher T.

    2008-10-21

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  1. Antenna structure with distributed strip

    SciTech Connect

    Rodenbeck, Christopher T.

    2008-03-18

    An antenna comprises electrical conductors arranged to form a radiating element including a folded line configuration and a distributed strip configuration, where the radiating element is in proximity to a ground conductor. The folded line and the distributed strip can be electrically interconnected and substantially coplanar. The ground conductor can be spaced from, and coplanar to, the radiating element, or can alternatively lie in a plane set at an angle to the radiating element. Embodiments of the antenna include conductor patterns formed on a printed wiring board, having a ground plane, spacedly adjacent to and coplanar with the radiating element. Other embodiments of the antenna comprise a ground plane and radiating element on opposed sides of a printed wiring board. Other embodiments of the antenna comprise conductors that can be arranged as free standing "foils". Other embodiments include antennas that are encapsulated into a package containing the antenna.

  2. Digitally controlled distributed phase shifter

    SciTech Connect

    Hietala, V.M.; Kravitz, S.H.; Vawter, G.A.

    1992-12-31

    A digitally controlled distributed phase shifter is comprised of N phase shifters. Digital control is achieved by using N binary length-weighted electrodes located on the top surface of a waveguide. A control terminal is attached to each electrode thereby allowing the application of a control signal. The control signal is either one of two discrete bias voltages. The application of the discrete bias voltages change the modal index of a portion of the waveguide that corresponds to a length of the electrode to which the bias voltage is applied, thereby causing the phase to change through the underlying portion of the waveguide. The digitally controlled distributed phase shift network has a total phase shift comprised of the sum of the individual phase shifters.

  3. Secure key storage and distribution

    DOEpatents

    Agrawal, Punit

    2015-06-02

    This disclosure describes a distributed, fault-tolerant security system that enables the secure storage and distribution of private keys. In one implementation, the security system includes a plurality of computing resources that independently store private keys provided by publishers and encrypted using a single security system public key. To protect against malicious activity, the security system private key necessary to decrypt the publication private keys is not stored at any of the computing resources. Rather portions, or shares of the security system private key are stored at each of the computing resources within the security system and multiple security systems must communicate and share partial decryptions in order to decrypt the stored private key.

  4. Enhanced distributed energy resource system

    DOEpatents

    Atcitty, Stanley; Clark, Nancy H.; Boyes, John D.; Ranade, Satishkumar J.

    2007-07-03

    A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

  5. Distributed Supervisory Protection Interlock System

    SciTech Connect

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

    1989-03-01

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

  6. SAMICS marketing and distribution model

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A SAMICS (Solar Array Manufacturing Industry Costing Standards) was formulated as a computer simulation model. Given a proper description of the manufacturing technology as input, this model computes the manufacturing price of solar arrays for a broad range of production levels. This report presents a model for computing these marketing and distribution costs, the end point of the model being the loading dock of the final manufacturer.

  7. Distribution-free discriminant analysis

    SciTech Connect

    Burr, T.; Doak, J.

    1997-05-01

    This report describes our experience in implementing a non-parametric (distribution-free) discriminant analysis module for use in a wide range of pattern recognition problems. Issues discussed include performance results on both real and simulated data sets, comparisons to other methods, and the computational environment. In some cases, this module performs better than other existing methods. Nearly all cases can benefit from the application of multiple methods.

  8. Power management and distribution technology

    NASA Technical Reports Server (NTRS)

    Dickman, John Ellis

    1993-01-01

    Power management and distribution (PMAD) technology is discussed in the context of developing working systems for a piloted Mars nuclear electric propulsion (NEP) vehicle. The discussion is presented in vugraph form. The following topics are covered: applications and systems definitions; high performance components; the Civilian Space Technology Initiative (CSTI) high capacity power program; fiber optic sensors for power diagnostics; high temperature power electronics; 200 C baseplate electronics; high temperature component characterization; a high temperature coaxial transformer; and a silicon carbide mosfet.

  9. Charge Distribution in Mesospheric Clouds

    SciTech Connect

    Misra, Shikha; Mishra, S. K.; Sodha, M. S.

    2011-11-29

    This work presents an analytical model for the physical understanding of the charge distribution on pure (with high work function) and dirty (with low work function) ice dust particles in polar mesospheric clouds PMCs (NLCs and PMSEs). The analysis is based on number and energy balance of constituents and allows the charge to be only an integral multiple (positive or negative) of the electronic charge.

  10. The data distribution satellite system

    NASA Technical Reports Server (NTRS)

    Bruno, Ronald C.; Weinberg, Aaron

    1991-01-01

    The Data Distributed Satellite (DDS) will be capable of providing the space research community with inexpensive and easy access to space payloads and space data. Furthermore, the DDS is shown to be a natural outgrowth of advances and evolution in both NASA's Space Network and commercial satellite communications. The roadmap and timescale for this evolution is described along with key demonstrations, proof-of-concept models, and required technology development that will support the projected system evolution toward the DDS.

  11. Small Aircraft Data Distribution System

    NASA Technical Reports Server (NTRS)

    Chazanoff, Seth L.; Dinardo, Steven J.

    2012-01-01

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

  12. CEBAF Distributed Data Acquisition System

    SciTech Connect

    Trent Allison; Thomas Powers

    2005-05-01

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

  13. DIstributed VIRtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, Clifford B.

    1995-01-01

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

  14. Distributed Relaxation for Conservative Discretizations

    NASA Technical Reports Server (NTRS)

    Diskin, Boris; Thomas, James L.

    2001-01-01

    A multigrid method is defined as having textbook multigrid efficiency (TME) if the solutions to the governing system of equations are attained in a computational work that is a small (less than 10) multiple of the operation count in one target-grid residual evaluation. The way to achieve this efficiency is the distributed relaxation approach. TME solvers employing distributed relaxation have already been demonstrated for nonconservative formulations of high-Reynolds-number viscous incompressible and subsonic compressible flow regimes. The purpose of this paper is to provide foundations for applications of distributed relaxation to conservative discretizations. A direct correspondence between the primitive variable interpolations for calculating fluxes in conservative finite-volume discretizations and stencils of the discretized derivatives in the nonconservative formulation has been established. Based on this correspondence, one can arrive at a conservative discretization which is very efficiently solved with a nonconservative relaxation scheme and this is demonstrated for conservative discretization of the quasi one-dimensional Euler equations. Formulations for both staggered and collocated grid arrangements are considered and extensions of the general procedure to multiple dimensions are discussed.

  15. Distributed Virtual System (DIVIRS) Project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1993-01-01

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

  16. Redshifts distribution in A262

    NASA Astrophysics Data System (ADS)

    Hassan, M. S. R.; Abidin, Z. Z.; Ibrahim, U. F. S. U.; Hashim, N.; Lee, D. A. A.

    2016-05-01

    Galaxy clusters are the largest virialized systems in the Universe containing a collection of galaxies of different redshifts. The redshift distribution of galaxies in galaxy clusters is concentrated at a certain redshift range which remarkably tells us that only the galaxies in a certain radial range belong to the galaxy cluster. This leads to a boundary estimation of the cluster. Background and foreground systems are represented by a histogram that determines whether some of the galaxies are too far or too high in redshift to be counted as the member of the cluster. With the recent advances in multifibre spectroscopy, it has become possible to perform detailed analysis of the redshift distribution of several galaxy clusters in the Abell Catalogue. This has given rise to significantly improved estimates of cluster membership, extent and dynamical history. Here we present a spectroscopic analysis of the galaxy cluster A262. We find 55 galaxies fall within z = 0.0143 and 0.0183 with velocity range 4450-5300 km s-1, and are therefore members of the cluster. We derived a new mean redshift of z = 0.016 173 ± 0.000 074 (4852 ± 22 km s-1) for the system of which we compare with our neutral hydrogen (H I) detection which peaks at 4970 ± 0.5 km s-1. It is found that the distribution of H I tends to be located at the edge of the cluster since most of spiral rich galaxies were away from cluster centre.

  17. Energy conservation in electric distribution

    SciTech Connect

    Lee, Chong-Jin

    1994-12-31

    This paper discusses the potential for energy and power savings that exist in electric power delivery systems. These savings translate into significant financial and environmental benefits for electricity producers and consumers as well as for society in general. AlliedSignal`s knowledge and perspectives on this topic are the result of discussions with hundreds of utility executives, government officials and other industry experts over the past decade in conjunction with marketing our Amorphous Metal technology for electric distribution transformers. Amorphous metal is a technology developed by AlliedSignal that significantly reduces the energy lost in electric distribution transformers at an incremental cost of just a few cents per kilo-Watt-hour. The purpose of this paper is to discuss: Amorphous Metal Alloy Technology; Energy Savings Opportunity; The Industrial Barriers and Remedies; Worldwide Demand; and A Low Risk Strategy. I wish this presentation will help KEPCO achieve their stated aims of ensuring sound development of the national economy and enhancement of public life through the economic and stable supply of electric power. AlliedSignal Korea Ltd. in conjunction with AlliedSignal Amorphous Metals in the U.S. are here to work with KEPCO, transformer manufacturers, industry, and government agencies to achieve greater efficiency in power distribution.

  18. Jefferson Lab's Distributed Data Acquisition

    SciTech Connect

    Trent Allison; Thomas Powers

    2006-05-01

    Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) occasionally experiences fast intermittent beam instabilities that are difficult to isolate and result in downtime. The Distributed Data Acquisition (Dist DAQ) system is being developed to detect and quickly locate such instabilities. It will consist of multiple Ethernet based data acquisition chassis distributed throughout the seven-eights of a mile CEBAF site. Each chassis will monitor various control system signals that are only available locally and/or monitored by systems with small bandwidths that cannot identify fast transients. The chassis will collect data at rates up to 40 Msps in circular buffers that can be frozen and unrolled after an event trigger. These triggers will be derived from signals such as periodic timers or accelerator faults and be distributed via a custom fiber optic event trigger network. This triggering scheme will allow all the data acquisition chassis to be triggered simultaneously and provide a snapshot of relevant CEBAF control signals. The data will then be automatically analyzed for frequency content and transients to determine if and where instabilities exist.

  19. Probability distributions of turbulent energy.

    PubMed

    Momeni, Mahdi; Müller, Wolf-Christian

    2008-05-01

    Probability density functions (PDFs) of scale-dependent energy fluctuations, P[deltaE(l)] , are studied in high-resolution direct numerical simulations of Navier-Stokes and incompressible magnetohydrodynamic (MHD) turbulence. MHD flows with and without a strong mean magnetic field are considered. For all three systems it is found that the PDFs of inertial range energy fluctuations exhibit self-similarity and monoscaling in agreement with recent solar-wind measurements [Hnat, Geophys. Res. Lett. 29, 86 (2002)]. Furthermore, the energy PDFs exhibit similarity over all scales of the turbulent system showing no substantial qualitative change of shape as the scale of the fluctuations varies. This is in contrast to the well-known behavior of PDFs of turbulent velocity fluctuations. In all three cases under consideration the P[deltaE(l)] resemble Lévy-type gamma distributions approximately Delta;{-1} exp(-|deltaE|/Delta)|deltaE|;{-gamma} The observed gamma distributions exhibit a scale-dependent width Delta(l) and a system-dependent gamma . The monoscaling property reflects the inertial-range scaling of the Elsässer-field fluctuations due to lacking Galilei invariance of deltaE . The appearance of Lévy distributions is made plausible by a simple model of energy transfer. PMID:18643170

  20. DIstributed VIRtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1994-01-01

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

  1. Antiquark distributions in the proton

    SciTech Connect

    Brooks, M.; Carey, T.; Garvey, G.

    1997-07-01

    This is the final report of a three-year Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The study of quark and antiquark distributions in the nucleon has been a major endeavor in nuclear and particle physics. Results from a recent deep-inelastic scattering experiment suggest the surprising possibility that the up and down antiquark distributions in the proton are not symmetric. A sensitive and direct determination of the antiquark distributions in the proton can be made by comparing the Drell-Yan cross sections on hydrogen versus deuterium targets. The authors have proposed a new experiment (E866) at Fermilab to carry out such measurements. E866 has been taking data since September 1996. Preliminary results show that the apparatus is working very well. The authors anticipate having seven months of beam in 1997, which would allow them to achieve the sensitivities for a definitive measurement of flavor symmetry of sea quarks in the proton.

  2. Preliminary Iron Distribution on Vesta

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Mittlefehldt, David W.

    2013-01-01

    The distribution of iron on the surface of the asteroid Vesta was investigated using Dawn's Gamma Ray and Neutron Detector (GRaND) [1,2]. Iron varies predictably with rock type for the howardite, eucrite, and diogenite (HED) meteorites, thought to be representative of Vesta. The abundance of Fe in howardites ranges from about 12 to 15 wt.%. Basaltic eucrites have the highest abundance, whereas, lower crustal and upper mantle materials (cumulate eucrites and diogenites) have the lowest, and howardites are intermediate [3]. We have completed a mapping study of 7.6 MeV gamma rays produced by neutron capture by Fe as measured by the bismuth germanate (BGO) detector of GRaND [1]. The procedures to determine Fe counting rates are presented in detail here, along with a preliminary distribution map, constituting the necessary initial step to quantification of Fe abundances. We find that the global distribution of Fe counting rates is generally consistent with independent mineralogical and compositional inferences obtained by other instruments on Dawn such as measurements of pyroxene absorption bands by the Visual and Infrared Spectrometer (VIR) [4] and Framing Camera (FC) [5] and neutron absorption measurements by GRaND [6].

  3. Distributed Virtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1993-01-01

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

  4. Distributed and Collaborative Software Analysis

    NASA Astrophysics Data System (ADS)

    Ghezzi, Giacomo; Gall, Harald C.

    Throughout the years software engineers have come up with a myriad of specialized tools and techniques that focus on a certain type of software analysissoftware analysis such as source code analysis, co-change analysis or bug prediction. However, easy and straight forward synergies between these analyses and tools rarely exist because of their stand-alone nature, their platform dependence, their different input and output formats and the variety of data to analyze. As a consequence, distributed and collaborative software analysiscollaborative software analysis scenarios and in particular interoperability are severely limited. We describe a distributed and collaborative software analysis platform that allows for a seamless interoperability of software analysis tools across platform, geographical and organizational boundaries. We realize software analysis tools as services that can be accessed and composed over the Internet. These distributed analysis services shall be widely accessible in our incrementally augmented Software Analysis Broker software analysis broker where organizations and tool providers can register and share their tools. To allow (semi-) automatic use and composition of these tools, they are classified and mapped into a software analysis taxonomy and adhere to specific meta-models and ontologiesontologies for their category of analysis.

  5. Infrastructure for distributed enterprise simulation

    SciTech Connect

    Johnson, M.M.; Yoshimura, A.S.; Goldsby, M.E.

    1998-01-01

    Traditional discrete-event simulations employ an inherently sequential algorithm and are run on a single computer. However, the demands of many real-world problems exceed the capabilities of sequential simulation systems. Often the capacity of a computer`s primary memory limits the size of the models that can be handled, and in some cases parallel execution on multiple processors could significantly reduce the simulation time. This paper describes the development of an Infrastructure for Distributed Enterprise Simulation (IDES) - a large-scale portable parallel simulation framework developed to support Sandia National Laboratories` mission in stockpile stewardship. IDES is based on the Breathing-Time-Buckets synchronization protocol, and maps a message-based model of distributed computing onto an object-oriented programming model. IDES is portable across heterogeneous computing architectures, including single-processor systems, networks of workstations and multi-processor computers with shared or distributed memory. The system provides a simple and sufficient application programming interface that can be used by scientists to quickly model large-scale, complex enterprise systems. In the background and without involving the user, IDES is capable of making dynamic use of idle processing power available throughout the enterprise network. 16 refs., 14 figs.

  6. Building a generalized distributed system model

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi

    1991-01-01

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

  7. 21 CFR 820.160 - Distribution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Distribution. 820.160 Section 820.160 Food and... QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.160 Distribution. (a) Each manufacturer shall establish and maintain procedures for control and distribution of...

  8. 40 CFR 152.132 - Supplemental distribution.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Supplemental distribution. 152.132... Supplemental distribution. The registrant may distribute or sell his registered product under another person's name and address instead of (or in addition to) his own. Such distribution and sale is...

  9. 21 CFR 820.160 - Distribution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Distribution. 820.160 Section 820.160 Food and... QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.160 Distribution. (a) Each manufacturer shall establish and maintain procedures for control and distribution of...

  10. 40 CFR 152.132 - Supplemental distribution.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Supplemental distribution. 152.132... Supplemental distribution. The registrant may distribute or sell his registered product under another person's name and address instead of (or in addition to) his own. Such distribution and sale is...

  11. 30 CFR 57.12006 - Distribution boxes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Distribution boxes. 57.12006 Section 57.12006... and Underground § 57.12006 Distribution boxes. Distribution boxes shall be provided with a... deenergized, and the distribution box shall be labeled to show which circuit each device controls....

  12. 30 CFR 57.12006 - Distribution boxes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distribution boxes. 57.12006 Section 57.12006... and Underground § 57.12006 Distribution boxes. Distribution boxes shall be provided with a... deenergized, and the distribution box shall be labeled to show which circuit each device controls....

  13. Television Distribution System for Primary Schools.

    ERIC Educational Resources Information Center

    South Australia Education Dept., Adelaide.

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

  14. World-wide distribution automation systems

    SciTech Connect

    Devaney, T.M.

    1994-12-31

    A worldwide power distribution automation system is outlined. Distribution automation is defined and the status of utility automation is discussed. Other topics discussed include a distribution management system, substation feeder, and customer functions, potential benefits, automation costs, planning and engineering considerations, automation trends, databases, system operation, computer modeling of system, and distribution management systems.

  15. Statistical Physics for Adaptive Distributed Control

    NASA Technical Reports Server (NTRS)

    Wolpert, David H.

    2005-01-01

    A viewgraph presentation on statistical physics for distributed adaptive control is shown. The topics include: 1) The Golden Rule; 2) Advantages; 3) Roadmap; 4) What is Distributed Control? 5) Review of Information Theory; 6) Iterative Distributed Control; 7) Minimizing L(q) Via Gradient Descent; and 8) Adaptive Distributed Control.

  16. Problem solving in a distributed environment

    NASA Technical Reports Server (NTRS)

    Rashid, R. F.

    1980-01-01

    Distributed problem solving is anayzed as a blend of two disciplines: (1) problem solving and ai; and (2) distributed systems (monitoring). It may be necessary to distribute because the application itself is one of managing distributed resources (e.g., distributed sensor net) and communication delays preclude centralized processing, or it may be desirable to distribute because a single computational engine may not satisfy the needs of a given task. In addition, considerations of reliability may dictate distribution. Examples of multi-process language environment are given.

  17. Invariant distributions on compact homogeneous spaces

    SciTech Connect

    Gorbatsevich, V V

    2013-12-31

    In this paper, we study distributions on compact homogeneous spaces, including invariant distributions and also distributions admitting a sub-Riemannian structure. We first consider distributions of dimension 1 and 2 on compact homogeneous spaces. After this, we study the cases of compact homogeneous spaces of dimension 2, 3, and 4 in detail. Invariant distributions on simply connected compact homogeneous spaces are also treated. Bibliography: 18 titles.

  18. A distributed clients/distributed servers model for STARCAT

    NASA Technical Reports Server (NTRS)

    Pirenne, B.; Albrecht, M. A.; Durand, D.; Gaudet, S.

    1992-01-01

    STARCAT, the Space Telescope ARchive and CATalogue user interface has been along for a number of years already. During this time it has been enhanced and augmented in a number of different fields. This time, we would like to dwell on a new capability allowing geographically distributed user interfaces to connect to geographically distributed data servers. This new concept permits users anywhere on the internet running STARCAT on their local hardware to access e.g., whichever of the 3 existing HST archive sites is available, or get information on the CFHT archive through a transparent connection to the CADC in BC or to get the La Silla weather by connecting to the ESO database in Munich during the same session. Similarly PreView (or quick look) images and spectra will also flow directly to the user from wherever it is available. Moving towards an 'X'-based STARCAT is another goal being pursued: a graphic/image server and a help/doc server are currently being added to it. They should further enhance the user independence and access transparency.

  19. The pulsar spectral index distribution

    NASA Astrophysics Data System (ADS)

    Bates, S. D.; Lorimer, D. R.; Verbiest, J. P. W.

    2013-05-01

    The flux-density spectra of radio pulsars are known to be steep and, to first order, described by a power-law relationship of the form Sν ∝ να, where Sν is the flux density at some frequency ν and α is the spectral index. Although measurements of α have been made over the years for several hundred pulsars, a study of the intrinsic distribution of pulsar spectra has not been carried out. From the result of pulsar surveys carried out at three different radio frequencies, we use population synthesis techniques and a likelihood analysis to deduce what underlying spectral index distribution is required to replicate the results of these surveys. We find that in general the results of the surveys can be modelled by a Gaussian distribution of spectral indices with a mean of -1.4 and unit standard deviation. We also consider the impact of the so-called gigahertz-peaked spectrum pulsars proposed by Kijak et al. The fraction of peaked-spectrum sources in the population with any significant turnover at low frequencies appears to be at most 10 per cent. We demonstrate that high-frequency (>2 GHz) surveys preferentially select flatter spectrum pulsars and the converse is true for lower frequency (<1 GHz) surveys. This implies that any correlations between α and other pulsar parameters (for example age or magnetic field) need to carefully account for selection biases in pulsar surveys. We also expect that many known pulsars which have been detected at high frequencies will have shallow, or positive, spectral indices. The majority of pulsars do not have recorded flux density measurements over a wide frequency range, making it impossible to constrain their spectral shapes. We also suggest that such measurements would allow an improved description of any populations of pulsars with `non-standard' spectra. Further refinements to this picture will soon be possible from the results of surveys with the Green Bank Telescope and LOFAR.

  20. Atlas of quasar energy distributions

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Wilkes, Belinda J.; Mcdowell, Jonathan C.; Green, Richard F.; Bechtold, Jill; Willner, S. P.; Oey, M. S.; Polomski, Elisha; Cutri, Roc

    1994-01-01

    We present an atlas of the spectral energy distributions (SEDs) of normal, nonblazar, quasars over the whole available range (radio to 10 keV X-rays) of the electromagnetic spectrum. The primary (UVSX) sample includes 47 quasars for which the spectral energy distributions include X-ray spectral indices and UV data. Of these, 29 are radio quiet, and 18 are radio loud. The SEDs are presented both in figures and in tabular form, with additional tabular material published on CD-ROM. Previously unpublished observational data for a second set of quasars excluded from the primary sample are also tabulated. The effects of host galaxy starlight contamination and foreground extinction on the UVSX sample are considered and the sample is used to investigate the range of SED properties. Of course, the properties we derive are influenced strongly by the selection effects induced by quasar discovery techniques. We derive the mean energy distribution (MED) for radio-loud and radio-quiet objects and present the bolometric corrections derived from it. We note, however, that the dispersion about this mean is large (approximately one decade for both the infrared and ultraviolet components when the MED is normalized at the near-infrared inflection). At least part of the dispersion in the ultraviolet may be due to time variability, but this is unlikely to be important in the infrared. The existence of such a large dispersion indicates that the MED reflects only some of the properties of quasars and so should be used only with caution.

  1. Force distributions in granular materials

    NASA Astrophysics Data System (ADS)

    Jaeger, Heinrich M.

    2002-03-01

    A fundamental problem in the study of disordered materials concerns the propagation of forces. Static granular media, such as sand particles inside a rigid container, have emerged as an important model system as they embody the zero temperature limit of disordered materials comprised of hardsphere repulsive particles. In this talk, I will review recent results on the distribution forces along the boundaries of granular material subjected to an applied load. While the spatial distribution of mean forces sensitively reflects the (macroscopic) packing structure of the material, the ensemble-averaged probability distribution of force fluctuations around the mean value, P(f), exhibits universal behavior. The shape of P(f) is found to be independent not only of the macroscopic packing arrangement but also of the inter-particle friction and, over a wide range, of the applied external stress. This shape is characterized by an exponential decay in the probability density for fluctuations above the mean force and only a small reduction, by no more than a factor two, for fluctuations below the mean [1]. Surprisingly, the exponential, non-Gaussian behavior appears to hold up even in the case of highly compressible grains, and it also has been observed in simulations of supercooled liquids [2]. I will discuss the implications of these findings on our current understanding of stress transmission in disordered media in general, and on glassy behavior in particular. [1] D. L. Blair, N. W. Mueggenburg, A. H. Marshall, H. M. Jaeger, and S. R. Nagel, Phys. Rev. E 63, 041304 (2001). [2] S. O’Hern, S. A. Langer, A. J. Liu, and S. R. Nagel, Phys. Rev. Lett. 86, 111 (2001). * Work performed in collaboration with D. L. Blair, J. M. Erikson, A. H. Marshall, N. W. Mueggenburg, and S. R. Nagel.

  2. Universality of Charged Multiplicity Distributions

    SciTech Connect

    Goulianos, K.; /Rockefeller U.

    1981-12-01

    The charged multiplicity distributions of the diffractive and non-diffractive components of hadronic interactions, as well as those of hadronic states produced in other reactions, are described well by a universal Gaussian function that depends only on the available mass for pionization, has a maximum at n{sub o} {approx_equal} 2M{sup 1/2}, where M is the available mass in GeV, and a peak to width ratio n{sub o}/D {approx_equal} 2.

  3. The Distributed Processing Library (DPL)

    NASA Astrophysics Data System (ADS)

    Allan, D. J.

    The Distributed Processing Library (DPL) provides multiple processing services across heterogeneous collections of UNIX workstations for the ASTERIX data analysis package. The DPL programmer provides a worker task to perform the units of parallel computation, and writes the flow control logic in the client using DPL to manage queues of jobs on multiple workers. DPL conceals the interprocess communication from the client and worker processes allowing existing sequential algorithms to be adapted easily. The system has been tested on a mixture of machines running Solaris and OSF, and has shown that the library is useful for units of computation taking as little as 50 milliseconds.

  4. Flux distributions in jointed ? tapes

    NASA Astrophysics Data System (ADS)

    Koblischka, M. R.; Johansen, T. H.; Bratsberg, H.; Vase, P.

    1998-06-01

    Superconducting joints between monofilamentary, Ag-sheathed 0953-2048/11/6/005/img8 tapes were investigated by means of magneto-optic imaging. Two types of joint were studied; one joint with direct contact between the tape cores, and the other one with an Ag layer between them. The local flux distributions directly reveal the obstacles hindering the current flow through the joints. The direct contact of the tape cores provides joints which can carry about 80% of the current of the original tape, whereas the joints with the Ag layer are considerably worse. This difference becomes even more drastic in applied magnetic fields.

  5. Distributed GPU Computing in GIScience

    NASA Astrophysics Data System (ADS)

    Jiang, Y.; Yang, C.; Huang, Q.; Li, J.; Sun, M.

    2013-12-01

    Geoscientists strived to discover potential principles and patterns hidden inside ever-growing Big Data for scientific discoveries. To better achieve this objective, more capable computing resources are required to process, analyze and visualize Big Data (Ferreira et al., 2003; Li et al., 2013). Current CPU-based computing techniques cannot promptly meet the computing challenges caused by increasing amount of datasets from different domains, such as social media, earth observation, environmental sensing (Li et al., 2013). Meanwhile CPU-based computing resources structured as cluster or supercomputer is costly. In the past several years with GPU-based technology matured in both the capability and performance, GPU-based computing has emerged as a new computing paradigm. Compare to traditional computing microprocessor, the modern GPU, as a compelling alternative microprocessor, has outstanding high parallel processing capability with cost-effectiveness and efficiency(Owens et al., 2008), although it is initially designed for graphical rendering in visualization pipe. This presentation reports a distributed GPU computing framework for integrating GPU-based computing within distributed environment. Within this framework, 1) for each single computer, computing resources of both GPU-based and CPU-based can be fully utilized to improve the performance of visualizing and processing Big Data; 2) within a network environment, a variety of computers can be used to build up a virtual super computer to support CPU-based and GPU-based computing in distributed computing environment; 3) GPUs, as a specific graphic targeted device, are used to greatly improve the rendering efficiency in distributed geo-visualization, especially for 3D/4D visualization. Key words: Geovisualization, GIScience, Spatiotemporal Studies Reference : 1. Ferreira de Oliveira, M. C., & Levkowitz, H. (2003). From visual data exploration to visual data mining: A survey. Visualization and Computer Graphics, IEEE

  6. Distributed intelligence for supervisory control

    NASA Technical Reports Server (NTRS)

    Wolfe, W. J.; Raney, S. D.

    1987-01-01

    Supervisory control systems must deal with various types of intelligence distributed throughout the layers of control. Typical layers are real-time servo control, off-line planning and reasoning subsystems and finally, the human operator. Design methodologies must account for the fact that the majority of the intelligence will reside with the human operator. Hierarchical decompositions and feedback loops as conceptual building blocks that provide a common ground for man-machine interaction are discussed. Examples of types of parallelism and parallel implementation on several classes of computer architecture are also discussed.

  7. Synchronous Sampling for Distributed Experiments

    NASA Astrophysics Data System (ADS)

    Wittkamp, M.; Ettl, J.

    2015-09-01

    Sounding Rocket payloads, especially for atmospheric research, often consists of several independent sensors or experiments with different objectives. The data of these sensors can be combined in the post processing to improve the scientific results of the flight. One major requirement for this data-correlation is a common timeline for the measurements of the distributed experiments. Within this paper we present two ways to achieve absolute timing for asynchronously working experiments. The synchronization process is using the Global Positioning System (GPS) and a standard serial communication protocol for transport of timestamps and flight-states.

  8. Distributed Control with Collective Intelligence

    NASA Technical Reports Server (NTRS)

    Wolpert, David H.; Wheeler, Kevin R.; Tumer, Kagan

    1998-01-01

    We consider systems of interacting reinforcement learning (RL) algorithms that do not work at cross purposes , in that their collective behavior maximizes a global utility function. We call such systems COllective INtelligences (COINs). We present the theory of designing COINs. Then we present experiments validating that theory in the context of two distributed control problems: We show that COINs perform near-optimally in a difficult variant of Arthur's bar problem [Arthur] (and in particular avoid the tragedy of the commons for that problem), and we also illustrate optimal performance in the master-slave problem.

  9. Video distribution system cost model

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    A cost model that can be used to systematically identify the costs of procuring and operating satellite linked communications systems is described. The user defines a network configuration by specifying the location of each participating site, the interconnection requirements, and the transmission paths available for the uplink (studio to satellite), downlink (satellite to audience), and voice talkback (between audience and studio) segments of the network. The model uses this information to calculate the least expensive signal distribution path for each participating site. Cost estimates are broken downy by capital, installation, lease, operations and maintenance. The design of the model permits flexibility in specifying network and cost structure.

  10. Microbial distribution of selenocysteine lyase.

    PubMed Central

    Chocat, P; Esaki, N; Nakamura, T; Tanaka, H; Soda, K

    1983-01-01

    We studied the distribution of selenocysteine lyase, a novel enzyme catalyzing the conversion of selenocysteine into alanine and H2Se, which we first demonstrated in various mammalian tissues (Esaki et al., J. Biol. Chem. 257:4386-4391, 1982). Enzyme activity was found in various bacteria such as Alcaligenes viscolactis and Pseudomonas alkanolytica. No significant activity was found in yeasts and fungi. Selenocysteine lyases from A. viscolactis and P. alkanolytica acted specifically on L-selenocysteine and required pyridoxal 5'-phosphate as a cofactor. PMID:6225771

  11. The CJ12 parton distributions

    SciTech Connect

    Accardi, Alberto; Owens, Jeff F.

    2013-07-01

    Three new sets of next-to-leading order parton distribution functions (PDFs) are presented, determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed for the description of deep-inelastic scattering data at large x and low Q^2, and nuclear corrections for deuterium targets. The PDF sets correspond to three different models for the nuclear effects, and provide a more realistic uncertainty range for the d quark PDF compared with previous fits. Applications to weak boson production at colliders are also discussed.

  12. Distributed Accounting on the Grid

    NASA Technical Reports Server (NTRS)

    Thigpen, William; Hacker, Thomas J.; McGinnis, Laura F.; Athey, Brian D.

    2001-01-01

    By the late 1990s, the Internet was adequately equipped to move vast amounts of data between HPC (High Performance Computing) systems, and efforts were initiated to link together the national infrastructure of high performance computational and data storage resources together into a general computational utility 'grid', analogous to the national electrical power grid infrastructure. The purpose of the Computational grid is to provide dependable, consistent, pervasive, and inexpensive access to computational resources for the computing community in the form of a computing utility. This paper presents a fully distributed view of Grid usage accounting and a methodology for allocating Grid computational resources for use on a Grid computing system.

  13. Heat distribution by natural convection

    SciTech Connect

    Balcomb, J.D.

    1985-01-01

    Natural convection can provide adequate heat distribution in many situtations that arise in buildings. This is appropriate, for example, in passive solar buildings where some rooms tend to be more strongly solar heated than others or to reduce the number of heating units required in a building. Natural airflow and heat transport through doorways and other internal building apertures is predictable and can be accounted for in the design. The nature of natural convection is described, and a design chart is presented appropriate to a simple, single-doorway situation. Natural convective loops that can occur in buildings are described and a few design guidelines are presented.

  14. Workshop on momentum distributions: Summary

    SciTech Connect

    Simmons, R.O.

    1988-01-01

    This has been an extraordinary Workshop touching many branches of physics. The Workshop has treated momentum distributions in fluid and solid condensed matter, in nuclei, and in electronic systems. Both theoretical and experimental concepts and methods have been considered in all these branches. A variety of specific illustrations and applications in physical systems have been presented. One finds that some common unifying themes emerge. One finds, also, that some examples are available to illustrate where one branch is more mature than others and to contrast where expectations for future progress may be most encouraged. 6 refs., 2 figs.

  15. Model-free distributed learning

    NASA Technical Reports Server (NTRS)

    Dembo, Amir; Kailath, Thomas

    1990-01-01

    Model-free learning for synchronous and asynchronous quasi-static networks is presented. The network weights are continuously perturbed, while the time-varying performance index is measured and correlated with the perturbation signals; the correlation output determines the changes in the weights. The perturbation may be either via noise sources or orthogonal signals. The invariance to detailed network structure mitigates large variability between supposedly identical networks as well as implementation defects. This local, regular, and completely distributed mechanism requires no central control and involves only a few global signals. Thus it allows for integrated on-chip learning in large analog and optical networks.

  16. Measurement Of Spectral Power Distribution

    NASA Astrophysics Data System (ADS)

    Moore, J. R.

    1980-11-01

    The majority of spectroradiometers make measurements at a number of discrete wavelength settings spaced evenly across the spectrum. Many modern light sources such as fluorescent or metal halide lamps have complex line spectra which may not be properly evaluated by this method. An automated spectroradiometer system involving a non-stop spectral scan with continuous integration of the output signal from the detector is described. The method is designed to make accurate measurements of all types of spectral power distribution whether made up of lines or continuum or any mixture of the two.

  17. Distributed optimization system and method

    DOEpatents

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2003-06-10

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

  18. Plankton distribution and ocean dispersal.

    PubMed

    McManus, Margaret Anne; Woodson, C Brock

    2012-03-15

    Plankton are small organisms that dwell in oceans, seas and bodies of fresh water. In this review, we discuss life in the plankton, which involves a balance between the behavioral capabilities of the organism and the characteristics and movement of the water that surrounds it. In order to consider this balance, we discuss how plankton interact with their environment across a range of scales - from the smallest viruses and bacteria to larger phytoplankton and zooplankton. We find that the larger scale distributions of plankton, observed in coastal waters, along continental shelves and in ocean basins, are highly dependent upon the smaller scale interactions between the individual organism and its environment. Further, we discuss how larger scale organism distributions may affect the transport and/or retention of plankton in the ocean environment. The research reviewed here provides a mechanistic understanding of how organism behavior in response to the physical environment produces planktonic aggregations, which has a direct impact on the way marine ecosystems function. PMID:22357594

  19. Analyzing ion distributions around DNA.

    PubMed

    Lavery, Richard; Maddocks, John H; Pasi, Marco; Zakrzewska, Krystyna

    2014-07-01

    We present a new method for analyzing ion, or molecule, distributions around helical nucleic acids and illustrate the approach by analyzing data derived from molecular dynamics simulations. The analysis is based on the use of curvilinear helicoidal coordinates and leads to highly localized ion densities compared to those obtained by simply superposing molecular dynamics snapshots in Cartesian space. The results identify highly populated and sequence-dependent regions where ions strongly interact with the nucleic and are coupled to its conformational fluctuations. The data from this approach is presented as ion populations or ion densities (in units of molarity) and can be analyzed in radial, angular and longitudinal coordinates using 1D or 2D graphics. It is also possible to regenerate 3D densities in Cartesian space. This approach makes it easy to understand and compare ion distributions and also allows the calculation of average ion populations in any desired zone surrounding a nucleic acid without requiring references to its constituent atoms. The method is illustrated using microsecond molecular dynamics simulations for two different DNA oligomers in the presence of 0.15 M potassium chloride. We discuss the results in terms of convergence, sequence-specific ion binding and coupling with DNA conformation. PMID:24906882

  20. Spatial Distributions of Young Stars

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Hillenbrand, Lynne A.

    2008-10-01

    We analyze the spatial distribution of young stars in Taurus-Auriga and Upper Sco, as determined from the two-point correlation function (i.e., the mean surface density of neighbors). The corresponding power-law fits allow us to determine the fractal dimensions of each association's spatial distribution, measure the stellar velocity dispersions, and distinguish between the bound binary population and chance alignments of members. We find that the fractal dimension of Taurus is D ~ 1.05, consistent with its filamentary structure. The fractal dimension of Upper Sco may be even shallower (D ~ 0.7), but this fit is uncertain due to the limited area and possible spatially variable incompleteness. We also find that random stellar motions have erased all primordial structure on scales of lsim0.07° in Taurus and lsim1.7° in Upper Sco; given ages of ~1 and ~5 Myr, the corresponding internal velocity dispersions are ~0.2 and ~1.0 km s-1, respectively. Finally, we find that binaries can be distinguished from chance alignments at separations of lsim120'' (17,000 AU) in Taurus and lsim75'' (11,000 AU) in Upper Sco. The binary populations in these associations that we previously studied, spanning separations of 3''-30'', is dominated by binary systems. However, the few lowest mass pairs (Mprim <~ 0.3 M⊙) might be chance alignments.

  1. Distributed computing at the SSCL

    SciTech Connect

    Cormell, L.; White, R.

    1993-05-01

    The rapid increase in the availability of high performance, cost- effective RISC/UNIX workstations has been both a blessing and a curse. The blessing of having extremely powerful computing engines available on the desk top is well-known to many users. The user has tremendous freedom, flexibility, and control of his environment. That freedom can, however, become the curse of distributed computing. The user must become a system manager to some extent, he must worry about backups, maintenance, upgrades, etc. Traditionally these activities have been the responsibility of a central computing group. The central computing group, however, may find that it can no linger provide all of the traditional services. With the plethora of workstations now found on so many desktops throughout the entire campus or lab, the central computing group may be swamped by support requests. This talk will address several of these computer support and management issues by discussing the approach taken at the Superconducting Super Collider Laboratory. In addition, a brief review of the future directions of commercial products for distributed computing and management will be given.

  2. ANNs pinpoint underground distribution faults

    SciTech Connect

    Glinkowski, M.T.; Wang, N.C.

    1995-10-01

    Many offline fault location techniques in power distribution circuits involve patrolling along the lines or cables. In overhead distribution lines, most of the failures can be located quickly by visual inspection without the aid of special equipment. However, locating a fault in underground cable systems is more difficult. It involves additional equipment (e.g., thumpers, radars, etc.) to transform the invisibility of the cable into other forms of signals, such as acoustic sound and electromagnetic pulses. Trained operators must carry the equipment above the ground, follow the path of the signal, and draw lines on their maps in order to locate the fault. Sometimes, even smelling the burnt cable faults is a way of detecting the problem. These techniques are time consuming, not always reliable, and, as in the case of high-voltage dc thumpers, can cause additional damage to the healthy parts of the cable circuit. Online fault location in power networks that involve interconnected lines (cables) and multiterminal sources continues receiving great attention, with limited success in techniques that would provide simple and practical solutions. This article features a new online fault location technique that: uses the pattern recognition feature of artificial neural networks (ANNs); utilizes new capabilities of modern protective relaying hardware. The output of the neural network can be graphically displayed as a simple three-dimensional (3-D) chart that can provide an operator with an instantaneous indication of the location of the fault.

  3. Countercurrent distribution of biological cells

    NASA Technical Reports Server (NTRS)

    1982-01-01

    It is known that the addition of phosphate buffer to two polymer aqueous phase systems has a strong effect on the partition behavior of cells and other particles in such mixtures. The addition of sodium phosphate to aqueous poly(ethylene glycol) dextran phase systems causes a concentration-dependent shift in binodial on the phase diagram, progressively lowering the critical conditions for phase separation as the phosphate concentration is increased. Sodium chloride produces no significant shift in the critical point relative to the salt-free case. Accurate determinations of the phase diagram require measurements of the density of the phases; data is presented which allows this parameter to be calculated from polarimetric measurements of the dextran concentrations of both phases. Increasing polymer concentrations in the phase systems produce increasing preference of the phosphate for the dextran-rich bottom phase. Equilibrium dialysis experiments showed that poly(ethylene glycol) effectively rejected phosphate, and to a lesser extent chloride, but that dextran had little effect on the distribution of either salt. Increasing ionic strength via addition of 0.15 M NaCl to phase systems containing 0.01 M phosphate produces an increased concentration of phosphate ions in the bottom dextran-rich phase, the expected effect in this type of Donnan distribution.

  4. Distributed nestmate recognition in ants

    PubMed Central

    Esponda, Fernando; Gordon, Deborah M.

    2015-01-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  5. Ising model for distribution networks

    NASA Astrophysics Data System (ADS)

    Hooyberghs, H.; Van Lombeek, S.; Giuraniuc, C.; Van Schaeybroeck, B.; Indekeu, J. O.

    2012-01-01

    An elementary Ising spin model is proposed for demonstrating cascading failures (breakdowns, blackouts, collapses, avalanches, etc.) that can occur in realistic networks for distribution and delivery by suppliers to consumers. A ferromagnetic Hamiltonian with quenched random fields results from policies that maximize the gap between demand and delivery. Such policies can arise in a competitive market where firms artificially create new demand, or in a solidarity environment where too high a demand cannot reasonably be met. Network failure in the context of a policy of solidarity is possible when an initially active state becomes metastable and decays to a stable inactive state. We explore the characteristics of the demand and delivery, as well as the topological properties, which make the distribution network susceptible of failure. An effective temperature is defined, which governs the strength of the activity fluctuations which can induce a collapse. Numerical results, obtained by Monte Carlo simulations of the model on (mainly) scale-free networks, are supplemented with analytic mean-field approximations to the geometrical random field fluctuations and the thermal spin fluctuations. The role of hubs versus poorly connected nodes in initiating the breakdown of network activity is illustrated and related to model parameters.

  6. Overlapping clusters for distributed computation.

    SciTech Connect

    Mirrokni, Vahab; Andersen, Reid; Gleich, David F.

    2010-11-01

    Scalable, distributed algorithms must address communication problems. We investigate overlapping clusters, or vertex partitions that intersect, for graph computations. This setup stores more of the graph than required but then affords the ease of implementation of vertex partitioned algorithms. Our hope is that this technique allows us to reduce communication in a computation on a distributed graph. The motivation above draws on recent work in communication avoiding algorithms. Mohiyuddin et al. (SC09) design a matrix-powers kernel that gives rise to an overlapping partition. Fritzsche et al. (CSC2009) develop an overlapping clustering for a Schwarz method. Both techniques extend an initial partitioning with overlap. Our procedure generates overlap directly. Indeed, Schwarz methods are commonly used to capitalize on overlap. Elsewhere, overlapping communities (Ahn et al, Nature 2009; Mishra et al. WAW2007) are now a popular model of structure in social networks. These have long been studied in statistics (Cole and Wishart, CompJ 1970). We present two types of results: (i) an estimated swapping probability {rho}{infinity}; and (ii) the communication volume of a parallel PageRank solution (link-following {alpha} = 0.85) using an additive Schwarz method. The volume ratio is the amount of extra storage for the overlap (2 means we store the graph twice). Below, as the ratio increases, the swapping probability and PageRank communication volume decreases.

  7. Evaluation of distributed computing tools

    SciTech Connect

    Stanberry, L.

    1992-10-28

    The original goal stated in the collaboration agreement from LCC`s perspective was ``to show that networking tools available in UNICOS perform well enough to meet the requirements of LCC customers.`` This translated into evaluating how easy it was to port ELROS over CRI`s ISO 2.0, which itself is a port of ISODE to the Cray. In addition we tested the interoperability of ELROS and ISO 2.0 programs running on the Cray, and communicating with each other, and with servers or clients running on other machines. To achieve these goals from LCC`s side, we ported ELROS to the Cray, and also obtained and installed a copy of the ISO 2.0 distribution from CRI. CRI`s goal for the collaboration was to evaluate the usability of ELROS. In particular, we were interested in their potential feedback on the use of ELROS in implementing ISO protocols--whether ELROS would be easter to use and perform better than other tools that form part of the standard ISODE system. To help achieve these goals for CRI, we provided them with a distribution tar file containing the ELROS system, once we had completed our port of ELROS to the Cray.

  8. Evaluation of distributed computing tools

    SciTech Connect

    Stanberry, L.

    1992-10-28

    The original goal stated in the collaboration agreement from LCC's perspective was to show that networking tools available in UNICOS perform well enough to meet the requirements of LCC customers.'' This translated into evaluating how easy it was to port ELROS over CRI's ISO 2.0, which itself is a port of ISODE to the Cray. In addition we tested the interoperability of ELROS and ISO 2.0 programs running on the Cray, and communicating with each other, and with servers or clients running on other machines. To achieve these goals from LCC's side, we ported ELROS to the Cray, and also obtained and installed a copy of the ISO 2.0 distribution from CRI. CRI's goal for the collaboration was to evaluate the usability of ELROS. In particular, we were interested in their potential feedback on the use of ELROS in implementing ISO protocols--whether ELROS would be easter to use and perform better than other tools that form part of the standard ISODE system. To help achieve these goals for CRI, we provided them with a distribution tar file containing the ELROS system, once we had completed our port of ELROS to the Cray.

  9. Agent Communications using Distributed Metaobjects

    SciTech Connect

    Goldsmith, Steven Y.; Spires, Shannon V.

    1999-06-10

    There are currently two proposed standards for agent communication languages, namely, KQML (Finin, Lobrou, and Mayfield 1994) and the FIPA ACL. Neither standard has yet achieved primacy, and neither has been evaluated extensively in an open environment such as the Internet. It seems prudent therefore to design a general-purpose agent communications facility for new agent architectures that is flexible yet provides an architecture that accepts many different specializations. In this paper we exhibit the salient features of an agent communications architecture based on distributed metaobjects. This architecture captures design commitments at a metaobject level, leaving the base-level design and implementation up to the agent developer. The scope of the metamodel is broad enough to accommodate many different communication protocols, interaction protocols, and knowledge sharing regimes through extensions to the metaobject framework. We conclude that with a powerful distributed object substrate that supports metaobject communications, a general framework can be developed that will effectively enable different approaches to agent communications in the same agent system. We have implemented a KQML-based communications protocol and have several special-purpose interaction protocols under development.

  10. Distributed and collaborative synthetic environments

    NASA Technical Reports Server (NTRS)

    Bajaj, Chandrajit L.; Bernardini, Fausto

    1995-01-01

    Fast graphics workstations and increased computing power, together with improved interface technologies, have created new and diverse possibilities for developing and interacting with synthetic environments. A synthetic environment system is generally characterized by input/output devices that constitute the interface between the human senses and the synthetic environment generated by the computer; and a computation system running a real-time simulation of the environment. A basic need of a synthetic environment system is that of giving the user a plausible reproduction of the visual aspect of the objects with which he is interacting. The goal of our Shastra research project is to provide a substrate of geometric data structures and algorithms which allow the distributed construction and modification of the environment, efficient querying of objects attributes, collaborative interaction with the environment, fast computation of collision detection and visibility information for efficient dynamic simulation and real-time scene display. In particular, we address the following issues: (1) A geometric framework for modeling and visualizing synthetic environments and interacting with them. We highlight the functions required for the geometric engine of a synthetic environment system. (2) A distribution and collaboration substrate that supports construction, modification, and interaction with synthetic environments on networked desktop machines.

  11. Intelligent distributed medical image management

    NASA Astrophysics Data System (ADS)

    Garcia, Hong-Mei C.; Yun, David Y.

    1995-05-01

    The rapid advancements in high performance global communication have accelerated cooperative image-based medical services to a new frontier. Traditional image-based medical services such as radiology and diagnostic consultation can now fully utilize multimedia technologies in order to provide novel services, including remote cooperative medical triage, distributed virtual simulation of operations, as well as cross-country collaborative medical research and training. Fast (efficient) and easy (flexible) retrieval of relevant images remains a critical requirement for the provision of remote medical services. This paper describes the database system requirements, identifies technological building blocks for meeting the requirements, and presents a system architecture for our target image database system, MISSION-DBS, which has been designed to fulfill the goals of Project MISSION (medical imaging support via satellite integrated optical network) -- an experimental high performance gigabit satellite communication network with access to remote supercomputing power, medical image databases, and 3D visualization capabilities in addition to medical expertise anywhere and anytime around the country. The MISSION-DBS design employs a synergistic fusion of techniques in distributed databases (DDB) and artificial intelligence (AI) for storing, migrating, accessing, and exploring images. The efficient storage and retrieval of voluminous image information is achieved by integrating DDB modeling and AI techniques for image processing while the flexible retrieval mechanisms are accomplished by combining attribute- based and content-based retrievals.

  12. Distributed nestmate recognition in ants.

    PubMed

    Esponda, Fernando; Gordon, Deborah M

    2015-05-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  13. A distributed programming environment for Ada

    NASA Technical Reports Server (NTRS)

    Brennan, Peter; Mcdonnell, Tom; Mcfarland, Gregory; Timmins, Lawrence J.; Litke, John D.

    1986-01-01

    Despite considerable commercial exploitation of fault tolerance systems, significant and difficult research problems remain in such areas as fault detection and correction. A research project is described which constructs a distributed computing test bed for loosely coupled computers. The project is constructing a tool kit to support research into distributed control algorithms, including a distributed Ada compiler, distributed debugger, test harnesses, and environment monitors. The Ada compiler is being written in Ada and will implement distributed computing at the subsystem level. The design goal is to provide a variety of control mechanics for distributed programming while retaining total transparency at the code level.

  14. Distance distribution in configuration-model networks

    NASA Astrophysics Data System (ADS)

    Nitzan, Mor; Katzav, Eytan; Kühn, Reimer; Biham, Ofer

    2016-06-01

    We present analytical results for the distribution of shortest path lengths between random pairs of nodes in configuration model networks. The results, which are based on recursion equations, are shown to be in good agreement with numerical simulations for networks with degenerate, binomial, and power-law degree distributions. The mean, mode, and variance of the distribution of shortest path lengths are also evaluated. These results provide expressions for central measures and dispersion measures of the distribution of shortest path lengths in terms of moments of the degree distribution, illuminating the connection between the two distributions.

  15. Water Distribution and Removal Model

    SciTech Connect

    Y. Deng; N. Chipman; E.L. Hardin

    2005-08-26

    The design of the Yucca Mountain high level radioactive waste repository depends on the performance of the engineered barrier system (EBS). To support the total system performance assessment (TSPA), the Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is developed to describe the thermal, mechanical, chemical, hydrological, biological, and radionuclide transport processes within the emplacement drifts, which includes the following major analysis/model reports (AMRs): (1) EBS Water Distribution and Removal (WD&R) Model; (2) EBS Physical and Chemical Environment (P&CE) Model; (3) EBS Radionuclide Transport (EBS RNT) Model; and (4) EBS Multiscale Thermohydrologic (TH) Model. Technical information, including data, analyses, models, software, and supporting documents will be provided to defend the applicability of these models for their intended purpose of evaluating the postclosure performance of the Yucca Mountain repository system. The WD&R model ARM is important to the site recommendation. Water distribution and removal represents one component of the overall EBS. Under some conditions, liquid water will seep into emplacement drifts through fractures in the host rock and move generally downward, potentially contacting waste packages. After waste packages are breached by corrosion, some of this seepage water will contact the waste, dissolve or suspend radionuclides, and ultimately carry radionuclides through the EBS to the near-field host rock. Lateral diversion of liquid water within the drift will occur at the inner drift surface, and more significantly from the operation of engineered structures such as drip shields and the outer surface of waste packages. If most of the seepage flux can be diverted laterally and removed from the drifts before contacting the wastes, the release of radionuclides from the EBS can be controlled, resulting in a proportional reduction in dose release at the accessible environment. The purposes

  16. [Relations between reward-distribution patterns and distribution strategies: how five-year-old children distribute rewards].

    PubMed

    Tsutsu, Kiyomi

    2013-08-01

    The relationship between children's reward-distribution judgments and their distribution strategies was investigated. Five-year-old children (N = 61) were presented with two stories where two characters made different numbers of origami stars. The children were asked to distribute different numbers of rewards to the characters: equal to (Middle-N), less than (Small-N), or more than (Large-N) the total number of stars in each story. Distribution strategies were categorized into two types: One-round, where rewards were distributed in one round only, and Cyclic, where the rewards were distributed in several cycles across the characters. In the Small-N of both stories (4 or 8 rewards), most children distributed rewards equally. When the number of rewards was 4, more than half used the One-round strategy, but when it was 8, more than half used the Cyclic strategy. In the Middle-N and Large-N conditions, most equal distributions used the Cyclic strategy, whereas almost all the proportional-equity distributions were associated with the One-round strategy, and most ordinal-equity distributions used the Cyclic strategy. The relationships between automatic/controlled reward-distribution judgments and distribution strategies were discussed. PMID:24063154

  17. Duplex Direct Data Distribution System

    NASA Technical Reports Server (NTRS)

    Greenfield, Israel (Technical Monitor)

    2001-01-01

    The NASA Glenn Research Center (GRC) is developing and demonstrating communications and network technologies that are helping to enable the near-Earth space Internet. GRC envisions several service categories. The first of these categories is direct data distribution or D3 (pronounced "D-cubed"). Commercially provided D3 will make it possible to download a data set from a spacecraft, like the International Space Station. as easily as one can extract a file from a remote server today, using a file transfer protocol. In a second category, NASA spacecraft will make use of commercial satellite communication (SATCOM) systems. Some of those services will come from purchasing time on unused transponders that cover landmasses. While it is likely there will be gaps in service coverage, Internet services should be available using these systems. This report addresses alternative methods of implementing a full duplex enhancement of the GRC developed experimental Ka-Band Direct Data Distribution (D3) space-to-ground communication link. The resulting duplex version is called the Duplex Direct Data Distribution (D4) system. The D4 system is intended to provide high-data-rate commercial direct or internet-based communications service between the NASA spacecraft in low earth orbit (LEO) and the respective principal investigators associated with these spacecraft. Candidate commercial services were assessed regarding their near-term potential to meet NASA requirements. Candidates included Ka-band and V-band geostationary orbit and non-geostationary orbit satellite relay services and direct downlink ("LEO teleport") services. End-to-end systems concepts were examined and characterized in terms of alternative link layer architectures. Alternatives included a Direct Link, a Relay Link, a Hybrid Link, and a Dual Mode Link. The direct link assessment examined sample ground terminal placements and antenna angle issues. The SATCOM-based alternatives examined existing or proposed commercial

  18. Density Distributions of Cyclotrimethylenetrinitramines (RDX)

    SciTech Connect

    Hoffman, D M

    2002-03-19

    As part of the US Army Foreign Comparative Testing (FCT) program the density distributions of six samples of class 1 RDX were measured using the density gradient technique. This technique was used in an attempt to distinguish between RDX crystallized by a French manufacturer (designated insensitive or IRDX) from RDX manufactured at Holston Army Ammunition Plant (HAAP), the current source of RDX for Department of Defense (DoD). Two samples from different lots of French IRDX had an average density of 1.7958 {+-} 0.0008 g/cc. The theoretical density of a perfect RDX crystal is 1.806 g/cc. This yields 99.43% of the theoretical maximum density (TMD). For two HAAP RDX lots the average density was 1.786 {+-} 0.002 g/cc, only 98.89% TMD. Several other techniques were used for preliminary characterization of one lot of French IRDX and two lot of HAAP RDX. Light scattering, SEM and polarized optical microscopy (POM) showed that SNPE and Holston RDX had the appropriate particle size distribution for Class 1 RDX. High performance liquid chromatography showed quantities of HMX in HAAP RDX. French IRDX also showed a 1.1 C higher melting point compared to HAAP RDX in the differential scanning calorimetry (DSC) consistent with no melting point depression due to the HMX contaminant. A second part of the program involved characterization of Holston RDX recrystallized using the French process. After reprocessing the average density of the Holston RDX was increased to 1.7907 g/cc. Apparently HMX in RDX can act as a nucleating agent in the French RDX recrystallization process. The French IRDX contained no HMX, which is assumed to account for its higher density and narrower density distribution. Reprocessing of RDX from Holston improved the average density compared to the original Holston RDX, but the resulting HIRDX was not as dense as the original French IRDX. Recrystallized Holston IRDX crystals were much larger (3-500 {micro}m or more) then either the original class 1 HAAP RDX or

  19. Regional distribution of rat electroolfactogram.

    PubMed

    Ezeh, P I; Davis, L M; Scott, J W

    1995-06-01

    1. Electroolfactorgram (EOG) recordings were made from different regions of the rat olfactory epithelium to test for spatial distribution of odor responses. 2. The EOG recordings showed spatial distribution of the odor responses in the olfactory epithelium. While some odorants (amyl acetate, anisole, and ethyl butyrate) were more effective in evoking responses in the dorsal recess near the septum, other odorants (including limonene, cineole, cyclooctane, and hexane) were more effective in the lateral recesses among the turbinate bones. These differences were seen as statistically significant odorant-by-position interactions in analysis of variance. 3. Comparisons of recordings along the anteroposterior dimension of the epithelium produced smaller differences between the odor responses. These were not significant for 3-mm distances, but were statistically significant for 5- to 6-mm distances along the dorsomedial epithelium. 4. The latencies were significantly longer in the lateral recesses than in the medial region. This probably reflects a more tortuous air path along the turbinate bones to the lateral recesses. 5. The olfactory receptor cells were activated by antidromic stimulation via the nerve layer of the olfactory bulb. The population spikes evoked from the olfactory receptor cells could be suppressed by prior stimulation with odorants that evoked strong EOG responses. This collision of the antidromic action potentials with the odor-evoked action potentials indicates that the same population of receptor cells was activated in both cases. 6. The flow rate and duration of the artificial sniff were varied systematically in some experiments. The differential distribution of response sizes was present at all flow rates and sniff durations. Some odors (e.g., amyl acetate and anisole) produced increased responses in the epithelium of the lateral recesses when flow rates or sniff durations were high. We suggest that these changes may reflect the sorptive properties

  20. Distributed Aviation Concepts and Technologies

    NASA Technical Reports Server (NTRS)

    Moore, Mark D.

    2008-01-01

    Aviation has experienced one hundred years of evolution, resulting in the current air transportation system dominated by commercial airliners in a hub and spoke infrastructure. While the first fifty years involved disruptive technologies that required frequent vehicle adaptation, the second fifty years produced a stable evolutionary optimization of decreasing costs with increasing safety. This optimization has resulted in traits favoring a centralized service model with high vehicle productivity and cost efficiency. However, it may also have resulted in a system that is not sufficiently robust to withstand significant system disturbances. Aviation is currently facing rapid change from issues such as environmental damage, terrorism threat, congestion and capacity limitations, and cost of energy. Currently, these issues are leading to a loss of service for weaker spoke markets. These catalysts and a lack of robustness could result in a loss of service for much larger portions of the aviation market. The impact of other competing transportation services may be equally important as casual factors of change. Highway system forecasts indicate a dramatic slow down as congestion reaches a point of non-linearly increasing delay. In the next twenty-five years, there is the potential for aviation to transform itself into a more robust, scalable, adaptive, secure, safe, affordable, convenient, efficient and environmentally friendly system. To achieve these characteristics, the new system will likely be based on a distributed model that enables more direct services. Short range travel is already demonstrating itself to be inefficient with a centralized model, providing opportunities for emergent distributed services through air-taxi models. Technologies from the on-demand revolution in computers and communications are now available as major drivers for aviation on-demand adaptation. Other technologies such as electric propulsion are currently transforming the automobile

  1. Parton distributions from lattice QCD: an update

    SciTech Connect

    Detmold, W; Melnitchouk, W; Thomas, A W

    2004-04-01

    We review the extraction of parton distributions from their moments calculated in lattice QCD, focusing in particular on their extrapolation to the physical region. As examples, we consider both the unpolarized and polarized isovector parton distributions of the nucleon.

  2. Radon Transform and Light-Cone Distributions

    NASA Astrophysics Data System (ADS)

    Teryaev, O. V.

    2016-08-01

    The relevance of Radon transform for generalized and transverse momentum dependent parton distributions is discussed. The new application for conditional (fracture) parton distributions and dihadron fragmentation functions is suggested.

  3. Radon Transform and Light-Cone Distributions

    NASA Astrophysics Data System (ADS)

    Teryaev, O. V.

    2016-05-01

    The relevance of Radon transform for generalized and transverse momentum dependent parton distributions is discussed. The new application for conditional (fracture) parton distributions and dihadron fragmentation functions is suggested.

  4. Distributed PV Adoption in Maine Through 2021

    SciTech Connect

    Gagnon, Pieter; Sigrin, Ben

    2015-11-06

    NREL has used its dSolar (distributed solar) model to generate low-medium-high estimates of distributed PV adoption in Maine through 2021. This presentation gives a high-level overview of the model and modeling results.

  5. Distributive Justice and the Moral Development Curriculum.

    ERIC Educational Resources Information Center

    Krogh, Suzanne Lowell; Lamme, Linda Leonard

    1985-01-01

    Teaching strategies to help elementary social studies teachers teach distributive justice--i.e., fair sharing of available resources--are provided. Also described are the approximate age levels and the different levels of reasoning associated with distributive justice. (RM)

  6. Can Data Recognize Its Parent Distribution?

    SciTech Connect

    A.W.Marshall; J.C.Meza; and I. Olkin

    1999-05-01

    This study is concerned with model selection of lifetime and survival distributions arising in engineering reliability or in the medical sciences. We compare various distributions, including the gamma, Weibull and lognormal, with a new distribution called geometric extreme exponential. Except for the lognormal distribution, the other three distributions all have the exponential distribution as special cases. A Monte Carlo simulation was performed to determine sample sizes for which survival distributions can distinguish data generated by their own families. Two methods for decision are by maximum likelihood and by Kolmogorov distance. Neither method is uniformly best. The probability of correct selection with more than one alternative shows some surprising results when the choices are close to the exponential distribution.

  7. 21 CFR 225.110 - Distribution records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... distribution record shall include the date of shipment, the name and address of purchaser, the quantity shipped... identification shall appear on the distribution record or the label issued with each shipment. (2) The...

  8. The Molecular Weight Distribution of Polymer Samples

    ERIC Educational Resources Information Center

    Horta, Arturo; Pastoriza, M. Alejandra

    2007-01-01

    Various methods for the determination of the molecular weight distribution (MWD) of different polymer samples are presented. The study shows that the molecular weight averages and distribution of a polymerization completely depend on the characteristics of the reaction itself.

  9. Array distribution in data-parallel programs

    NASA Technical Reports Server (NTRS)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert; Sheffler, Thomas J.

    1994-01-01

    We consider distribution at compile time of the array data in a distributed-memory implementation of a data-parallel program written in a language like Fortran 90. We allow dynamic redistribution of data and define a heuristic algorithmic framework that chooses distribution parameters to minimize an estimate of program completion time. We represent the program as an alignment-distribution graph. We propose a divide-and-conquer algorithm for distribution that initially assigns a common distribution to each node of the graph and successively refines this assignment, taking computation, realignment, and redistribution costs into account. We explain how to estimate the effect of distribution on computation cost and how to choose a candidate set of distributions. We present the results of an implementation of our algorithms on several test problems.

  10. RANGELAND NUTRITIONAL PATTERNS AND CATTLE DISTRIBUTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several animal and environmental characteristics affect livestock distribution on rangelands. An understanding of mechanisms governing livestock distribution can help land and livestock managers avoid or ameliorate potential deleterious grazing effects. This research tested hypotheses that foragin...

  11. An improved distributed arithmetic architecture

    NASA Technical Reports Server (NTRS)

    Guo, X.; Lynn, D. W.

    1991-01-01

    Speed requirements have been, and will continue to be, a major consideration in the design of hardware to implement digital signal processing functions like digital filters and transforms like the DFT and DCT. The conventional approach is to increase speed by adding hardware and increasing chip area. The real challenge is to save chip area while still maintaining high speed performance. The approach we propose is based on the distributed arithmetic implementation (DA) of digital filters. The improvement is based on two observations. Firstly, a single memory element can replace several identical memory elements in a fully parallel DA implementation. Secondly, truncation or rounding may be introduced into the computation at strategic points without increasing error unduly. Both of these approaches can be used to attain area savings without impairing speed of operation.

  12. Geographic distribution of Bhanja virus.

    PubMed

    Hubálek, Z

    1987-01-01

    A review on the geographic distribution, vectors and hosts of Bhanja virus (Bunyaviridae) is based on reports about: isolations of the virus; antibody surveys. Bhanja virus has been isolated in 15 countries of Asia, Africa and Europe, and antibodies against it have been detected in 15 additional countries. Vector range includes ticks of the family Ixodidae (subfam. Amblyomminae; not subfam. Ixodinae): 13 species of 6 genera (Haemaphysalis, Dermacentor, Hyalomma, Amblyomma, Rhipicephalus and Boophilus) yielded the virus. Bhanja virus has only rarely been isolated from vertebrates (Atelerix, Xerus, Ovis, Bos; possibly bats), though antibodies have been detected frequently in a wide range of mammals (Ruminantia being the major hosts), in several species of birds (Passeriformes, Galliformes) and even reptiles (Ophisaurus apodus). Natural foci of the Bhanja virus infections are of the boskematic type (sensu Rosický), associated closely with pastures of domestic ruminants infested by ticks in the regions of tropical, subtropical and partly temperate climatic zones. PMID:3108117

  13. Cooperative Fault Tolerant Distributed Computing

    SciTech Connect

    Fagg, Graham E.

    2006-03-15

    HARNESS was proposed as a system that combined the best of emerging technologies found in current distributed computing research and commercial products into a very flexible, dynamically adaptable framework that could be used by applications to allow them to evolve and better handle their execution environment. The HARNESS system was designed using the considerable experience from previous projects such as PVM, MPI, IceT and Cumulvs. As such, the system was designed to avoid any of the common problems found with using these current systems, such as no single point of failure, ability to survive machine, node and software failures. Additional features included improved inter-component connectivity, with full support for dynamic down loading of addition components at run-time thus reducing the stress on application developers to build in all the libraries they need in advance.

  14. The Outer Halo Metallicity Distribution

    NASA Astrophysics Data System (ADS)

    MA, ZHIBO; Morrison, H.; Harding, P.; Xue, X.; Rix, H.; Rockosi, C.; Johnson, J.; Lee, Y.; Cudworth, K.

    2012-01-01

    We present a new determination of the metallicity distribution function in the Milky Way halo, based on an in situ sample of more than 5000 K giants from SDSS/SEGUE. We have also measured the metallicity gradient in the halo, using our sample which stretches from 5 kpc to more than 100 kpc from the galactic center. The halo metallicity gradient has been a controversial topic in recent studies, but our in-situ study overcomes the problems caused in these studies by their extrapolations from local samples to the distant halo. We also describe our extensive checks of the log g and [Fe/H] measurements from the SEGUE Stellar Parameters pipeline, using globular and open cluster stars and SEGUE stars with follow-up high-resolution analysis. In addition, we present a new Bayesian estimate of distances to the K giants, which avoids the distance bias introduced by the red giant branch luminosity function.

  15. Distributed simulation of network protocols

    NASA Technical Reports Server (NTRS)

    Paterra, Frank; Overstreet, C. Michael; Maly, Kurt J.

    1990-01-01

    Simulations of high speed network protocols are very CPU intensive operations requiring very long run times. Very high speed network protocols (Gigabit/sec rates) require longer simulation runs in order to reach a steady state, while at the same time requiring additional CPU processing for each unit of time because of the data rates for the traffic being simulated. As protocol development proceeds and simulations provide insights into any problems associated with the protocol, the simulation model often must be changed to generate additional or finer statistical performance information. Iterating on this process is very time consuming due to the required run times for the simulation models. The results of the efforts to distribute a high speed ring network protocol, Carrier Sensed Multiple Access/Ring Network (CSMA/RN), are presented.

  16. Distribution of multidirectional environmental effects

    SciTech Connect

    Bitner-Gregersen, E.M.

    1996-12-31

    An extension of the joint environmental model developed for Haltenbanken (off central Norway) is presented. The existing model is limited to the following environmental parameters: 1-hour mean wind speed, current speed, significant wave height (sea and swell), spectral peak period (sea and swell), the main wave direction (wind and current are assumed to be collinear with the main wave direction) and sea water level. The model has been based on experience gained from measurements and hindcast data from the Norwegian Continental Shelf. The extension of the joint environmental model includes the possibility of environmental effects approaching from different directions. It is based on hindcast data and developed for severe weather conditions. A procedure for inclusion a lower limit in the wave period distribution, as an alternative to application of a double peak spectrum, is also proposed. The model is meant to provide an input to reliability analysis of offshore structures.

  17. Embodied and Distributed Parallel DJing.

    PubMed

    Cappelen, Birgitta; Andersson, Anders-Petter

    2016-01-01

    Everyone has a right to take part in cultural events and activities, such as music performances and music making. Enforcing that right, within Universal Design, is often limited to a focus on physical access to public areas, hearing aids etc., or groups of persons with special needs performing in traditional ways. The latter might be people with disabilities, being musicians playing traditional instruments, or actors playing theatre. In this paper we focus on the innovative potential of including people with special needs, when creating new cultural activities. In our project RHYME our goal was to create health promoting activities for children with severe disabilities, by developing new musical and multimedia technologies. Because of the users' extreme demands and rich contribution, we ended up creating both a new genre of musical instruments and a new art form. We call this new art form Embodied and Distributed Parallel DJing, and the new genre of instruments for Empowering Multi-Sensorial Things. PMID:27534347

  18. The Distribution Patterns of Psoriasis

    PubMed Central

    Mitchell, J. C.

    1962-01-01

    Observation of the Koebner response was used in the clinical evaluation, determination of prognosis and management of seven patients with psoriasis. The Koebner response may be observed in patients with progressive and eruptive psoriasis; it is not the etiological factor but determines the localization of lesions when a psoriatic reaction is active. The eliciting stimuli for response are varied and non-specific; a common factor is cutaneous injury. Other skin diseases may provoke suitable eliciting cutaneous injury and determine the distribution patterns of sebo-psoriasis, psoriasis inversus, and psoriasiform neurodermatitis. Cutaneous injury is followed by repair or an attempt at repair. Psoriasis is a reaction pattern to non-specific stimuli in which psoriatic defect is brought to light by the increased rate of metabolism in cells regenerating after injury. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5 PMID:20327334

  19. On generalized distributions and pathways

    NASA Astrophysics Data System (ADS)

    Mathai, A. M.; Haubold, H. J.

    2008-03-01

    The scalar version of the pathway model of Mathai [A.M. Mathai, Linear Alg. Appl. 396 (2005) 317] is shown to be associated with a large number of probability models used in physics. Different families of densities are listed here, which are all connected through the pathway parameter α, generating a distributional pathway. The idea is to switch from one functional form to another through this parameter and it is shown that one can proceed from the generalized type-1 beta family to generalized type-2 beta family to generalized gamma family. It is also shown that the pathway model is available by maximizing a generalized measure of entropy, leading to an entropic pathway, covering the particularly interesting cases of Tsallis statistics [C. Tsallis, J. Stat. Phys. 52 (1988) 479] and superstatistics [C. Beck, E.G.D. Cohen, Physica A 322 (2003) 267].

  20. Concepts for Distributed Engine Control

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Thomas, Randy; Saus, Joseph

    2007-01-01

    Gas turbine engines for aero-propulsion systems are found to be highly optimized machines after over 70 years of development. Still, additional performance improvements are sought while reduction in the overall cost is increasingly a driving factor. Control systems play a vitally important part in these metrics but are severely constrained by the operating environment and the consequences of system failure. The considerable challenges facing future engine control system design have been investigated. A preliminary analysis has been conducted of the potential benefits of distributed control architecture when applied to aero-engines. In particular, reductions in size, weight, and cost of the control system are possible. NASA is conducting research to further explore these benefits, with emphasis on the particular benefits enabled by high temperature electronics and an open-systems approach to standardized communications interfaces.

  1. Distributed multi-sensor fusion

    NASA Astrophysics Data System (ADS)

    Scheffel, Peter; Fish, Robert; Knobler, Ron; Plummer, Thomas

    2008-03-01

    McQ has developed a broad based capability to fuse information in a geographic area from multiple sensors to build a better understanding of the situation. The paper will discuss the fusion architecture implemented by McQ to use many sensors and share their information. This multi sensor fusion architecture includes data sharing and analysis at the individual sensor, at communications nodes that connect many sensors together, at the system server/user interface, and across multi source information available through networked services. McQ will present a data fusion architecture that integrates a "Feature Information Base" (FIB) with McQ's well known Common Data Interchange Format (CDIF) data structure. The distributed multi sensor fusion provides enhanced situation awareness for the user.

  2. Measuring the Distribution of Spitefulness

    PubMed Central

    Kimbrough, Erik O.; Reiss, J. Philipp

    2012-01-01

    Spiteful, antisocial behavior may undermine the moral and institutional fabric of society, producing disorder, fear, and mistrust. Previous research demonstrates the willingness of individuals to harm others, but little is understood about how far people are willing to go in being spiteful (relative to how far they could have gone) or their consistency in spitefulness across repeated trials. Our experiment is the first to provide individuals with repeated opportunities to spitefully harm anonymous others when the decision entails zero cost to the spiter and cannot be observed as such by the object of spite. This method reveals that the majority of individuals exhibit consistent (non-)spitefulness over time and that the distribution of spitefulness is bipolar: when choosing whether to be spiteful, most individuals either avoid spite altogether or impose the maximum possible harm on their unwitting victims. PMID:22905108

  3. Hourly temporal distribution of wind

    NASA Astrophysics Data System (ADS)

    Deligiannis, Ilias; Dimitriadis, Panayiotis; Koutsoyiannis, Demetris

    2016-04-01

    The wind process is essential for hydrometeorology and additionally, is one of the basic renewable energy resources. Most stochastic forecast models are limited up to daily scales disregarding the hourly scale which is significant for renewable energy management. Here, we analyze hourly wind timeseries giving emphasis on the temporal distribution of wind within the day. We finally present a periodic model based on statistical as well as hydrometeorological reasoning that shows good agreement with data. Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students in the Assembly.

  4. Distribution of Culicoides in Greece.

    PubMed

    Patakakis, Michael J; Papazahariadou, Margarita; Wilson, Anthony; Mellor, Philip S; Frydas, Stavros; Papadopoulos, Orestis

    2009-12-01

    Culicoides biting midges (Diptera: Ceratopogonidae) were trapped between 1999 and 2004 at 122 locations in mainland Greece and on most of the larger Aegean and Ionian islands, using OVI light traps, in order to determine the distribution and seasonal activity of bluetongue virus vectors and other Culicoides species. Thirty-nine Culicoides species were identified, six of which (C. furcillatus, C. impunctatus, C. paolae, C. pictipennis, C. riethi, and C. scoticus) were identified for the first time in Greece. Two of these (C. impunctatus and C. scoticus) may be of veterinary importance due to their role as vectors of bluetongue virus and related orbiviruses. In addition, C. imicola was detected for the first time in mainland Greece. PMID:20836829

  5. Interoperability of heterogeneous distributed systems

    NASA Astrophysics Data System (ADS)

    Zaschke, C.; Essendorfer, B.; Kerth, C.

    2016-05-01

    To achieve knowledge superiority in today's operations interoperability is the key. Budget restrictions as well as the complexity and multiplicity of threats combined with the fact that not single nations but whole areas are subject to attacks force nations to collaborate and share information as appropriate. Multiple data and information sources produce different kinds of data, real time and non-real time, in different formats that are disseminated to the respective command and control level for further distribution. The data is most of the time highly sensitive and restricted in terms of sharing. The question is how to make this data available to the right people at the right time with the right granularity. The Coalition Shared Data concept aims to provide a solution to these questions. It has been developed within several multinational projects and evolved over time. A continuous improvement process was established and resulted in the adaptation of the architecture as well as the technical solution and the processes it supports. Coming from the idea of making use of existing standards and basing the concept on sharing of data through standardized interfaces and formats and enabling metadata based query the concept merged with a more sophisticated service based approach. The paper addresses concepts for information sharing to facilitate interoperability between heterogeneous distributed systems. It introduces the methods that were used and the challenges that had to be overcome. Furthermore, the paper gives a perspective how the concept could be used in the future and what measures have to be taken to successfully bring it into operations.

  6. Distributed etched diffraction grating demultiplexer

    NASA Astrophysics Data System (ADS)

    Jafari, Amir

    This doctoral thesis studies the concept of a distributed etched diffraction grating (DEDG) and presents a methodology to engineer the spectral response of the device. The design which incorporates a distributed Bragg reflector (DBR) at the facets of a conventional etched diffraction grating demultiplexer promises for a superior performance in multiple aspects. Where in a conventional etched diffraction grating, smooth vertical deep etched walls are required in order to realize a low insertion loss device; in the DEDG such requirement is significantly mitigated. Deep etched walls are replaced with shallowly etched diffraction grating facets followed by a DBR structure and as a result devices with significantly lower insertion loss are achievable. The feasibility of the application of DEDG as a wavelength demultiplexer was demonstrated through fabrication and characterization of a prototype device. The proof of concept device was fabricated using the state of the art deep UV optical lithography and reactive ion etching in a nano-photonic silicon-on-insulator (SOI) material platform. The fabricated device was then characterized in the lab. Furthermore, incorporation of the DBR structure at the facets of the conventional etched diffraction grating decouples the reflection and diffraction functionalities, rendering the DEDG suitable for spectral response engineering. According to the application, the output spectral response of the device can be tailored through careful design and optimization of the incorporated DBR. In this thesis, through numerical simulations we have shown that functionalities such as polarization independent performance and at top insertion loss envelop are viable. A methodology to engineer the spectral response of the DEDG is discussed in details.

  7. The genetics of fat distribution.

    PubMed

    Schleinitz, Dorit; Böttcher, Yvonne; Blüher, Matthias; Kovacs, Peter

    2014-07-01

    Fat stored in visceral depots makes obese individuals more prone to complications than subcutaneous fat. There is good evidence that body fat distribution (FD) is controlled by genetic factors. WHR, a surrogate measure of FD, shows significant heritability of up to ∼60%, even after adjusting for BMI. Genetic variants have been linked to various forms of altered FD such as lipodystrophies; however, the polygenic background of visceral obesity has only been sparsely investigated in the past. Recent genome-wide association studies (GWAS) for measures of FD revealed numerous loci harbouring genes potentially regulating FD. In addition, genes with fat depot-specific expression patterns (in particular subcutaneous vs visceral adipose tissue) provide plausible candidate genes involved in the regulation of FD. Many of these genes are differentially expressed in various fat compartments and correlate with obesity-related traits, thus further supporting their role as potential mediators of metabolic alterations associated with a distinct FD. Finally, developmental genes may at a very early stage determine specific FD in later life. Indeed, genes such as TBX15 not only manifest differential expression in various fat depots, but also correlate with obesity and related traits. Moreover, recent GWAS identified several polymorphisms in developmental genes (including TBX15, HOXC13, RSPO3 and CPEB4) strongly associated with FD. More accurate methods, including cardiometabolic imaging, for assessment of FD are needed to promote our understanding in this field, where the main focus is now to unravel the yet unknown biological function of these novel 'fat distribution genes'. PMID:24632736

  8. Ecophysiological controls of conifer distributions

    SciTech Connect

    Woodward, F.I.

    1995-07-01

    The boreal forest covers the most extensive worldwide area of conifer-dominated vegetation, with a total global area of about 12 million km{sup 2}. This large area is very species poor; in North America there are only nine widespread and dominant species of trees, of which six are conifers-Picea mariana, Picea glauca, Abies balsamea, Larix laricina, Pinus contorta, and Pinus banksiana. The remaining three angiosperms are Betula papyrifera, Populus tremuloides, and Populus balsamifera. In Fennoscandia and the former Soviet Union, 14 species dominate the boreal forest, 10 of which are conifers-Abies sibirica, Larix gmelinii, Larix sibirica, Larix sukaczewii, Picea abies, Picea ajanensis, Picea obovata, Pinus pumila, Pinus sibifica, and Pinus sylvestris. The dominant angiosperm trees are Betula pendula, Betula pubescens, Chosenia arbutifolia, and Populus tremula. Such species paucity detracts from realizing the remarkable capacity of these species to endure the harshest forest climates of the world. Both the short-term geological history and the current climate are major causes of the species paucity in the boreal forest. In general, the boreal forest has been present in its current distribution only since the Holocene era. In most cases, the dominant species of the boreal forest completed their postglacial expansion to their current distributions only over the past 2000 years. So the ecology of the forest is very young, in comparison with forests in warmer climates. It might be expected that over subsequent millennia, with no climatic change, there could be a slow influx of new species to the boreal zone; however, the extreme climatic, edaphic, and disturbance characteristics of the area are likely to set insurmountable limits on this influx of diversity.

  9. Aspects of Distributivity in Mandarin Chinese

    ERIC Educational Resources Information Center

    Tsai, Yaping

    2009-01-01

    One important task of any semantic theory of plurals is to account for the collective/distributive ambiguity. The goal of this dissertation is to achieve greater understanding of plurality and the collectivity/distributivity distinction from a cross-linguistic perspective by examining the phenomenon of distributivity in Mandarin Chinese. I show…

  10. The Tsallis distribution at the LHC: Phenomenology

    SciTech Connect

    Cleymans, J.

    2014-11-11

    An overview is presented of transverse momentum distributions of particles at the LHC using the Tsallis distribution. The use of a thermodynamically consistent form of this distribution leads to an excellent description of charged and identified particles. The values of the Tsallis parameter q are truly remarkably consistent.

  11. Distributive Education II. Course of Study.

    ERIC Educational Resources Information Center

    Nelson, Frank W.

    This curriculum guide for teacher-coordinators is designed to provide a course of study in distributive education (Distributive Education II) in Oklahoma. Content is in nine sections with each section consisting of one or more instructional units: (1) Orientation (Introduction to Distributive Occupations, DECA), (2) Survival Skills (Job…

  12. 21 CFR 225.110 - Distribution records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Distribution records. 225.110 Section 225.110 Food...: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Records and Reports § 225.110 Distribution records. (a) Distribution records permit the manufacturer to relate complaints to specific batches...

  13. 20 CFR 618.930 - Second distribution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Second distribution. 618.930 Section 618.930 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TRADE ADJUSTMENT ASSISTANCE... distribution. The Department will distribute at least 90 percent of the total training funds for a fiscal...

  14. Distributed Pervasive Worlds: The Case of Exergames

    ERIC Educational Resources Information Center

    Laine, Teemu H.; Sedano, Carolina Islas

    2015-01-01

    Pervasive worlds are computing environments where a virtual world converges with the physical world through context-aware technologies such as sensors. In pervasive worlds, technology is distributed among entities that may be distributed geographically. We explore the concept, possibilities, and challenges of distributed pervasive worlds in a case…

  15. Distributed Leadership through the Looking Glass

    ERIC Educational Resources Information Center

    Harris, Alma; Spillane, James

    2008-01-01

    Distributed leadership is an idea that is growing in popularity. There is widespread interest in the notion of distributing leadership although interpretations of the term vary. A distributed leadership perspective recognises that there are multiple leaders and that leadership activities are widely shared within and between organisations. A…

  16. 7 CFR 1000.5 - Distributing plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Distributing plant. 1000.5 Section 1000.5 Agriculture... Definitions § 1000.5 Distributing plant. Distributing plant means a plant that is approved by a duly... plants....

  17. 7 CFR 1000.5 - Distributing plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Distributing plant. 1000.5 Section 1000.5 Agriculture... Definitions § 1000.5 Distributing plant. Distributing plant means a plant that is approved by a duly... plants....

  18. 7 CFR 1000.5 - Distributing plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Distributing plant. 1000.5 Section 1000.5 Agriculture... Definitions § 1000.5 Distributing plant. Distributing plant means a plant that is approved by a duly... plants....

  19. 7 CFR 1000.5 - Distributing plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Distributing plant. 1000.5 Section 1000.5 Agriculture... Definitions § 1000.5 Distributing plant. Distributing plant means a plant that is approved by a duly... plants....

  20. 7 CFR 1000.5 - Distributing plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Distributing plant. 1000.5 Section 1000.5 Agriculture... Definitions § 1000.5 Distributing plant. Distributing plant means a plant that is approved by a duly... plants....

  1. Investigating School Leadership Practice: A Distributed Perspective.

    ERIC Educational Resources Information Center

    Spillane, James P.; Halverson, Richard; Diamond, John B.

    2001-01-01

    Argues for scholarship that investigates leadership practice; specifically, the practice of leading classroom instruction. Articulates a distributed perspective, grounded in activity theory and distributed cognition, to frame such investigations. Suggests that school leadership is best understood as a distributed practice stretched over the…

  2. 21 CFR 820.160 - Distribution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Distribution. 820.160 Section 820.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.160 Distribution. (a) Each manufacturer shall establish...

  3. Household income distribution in the USA

    NASA Astrophysics Data System (ADS)

    Efthimiou, Costas J.; Wearne, Adam

    2016-03-01

    In this article we present an alternative model for the distribution of household incomes in the United States. We provide arguments from two differing perspectives which both yield the proposed income distribution curve, and then fit this curve to empirical data on household income distribution obtained from the United States Census Bureau.

  4. Multimedia Environmental Distribution of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Liu, Haoyang Haven

    Engineered nanomaterials (ENMs), which may be released to the environment due to human-related activities, can move across environmental phase boundaries and be found in most media. Given the rapid development and growing applications of nanotechnology, there is concern and thus the need to assess the potential environmental impact associated with ENMs. Accordingly, a modeling platform was developed to enable evaluation of the dynamic multimedia environmental distribution of ENMs (MendNano) and the range of potential exposure concentrations of ENMs. The MendNano was based on a dynamic multimedia compartmental modeling approach that was guided by detailed analysis of the agglomeration of ENMs, life-cycle analysis based estimates of their potential release to the environment, and incorporation of mechanistic sub-models of various intermedia transport processes. Model simulations for various environmental scenarios indicated that ENM accumulation in the sediment increased significantly with increased ENMs attachment to suspended solids in water. Atmospheric dry and wet depositions can be important pathways for ENMs input to the terrestrial environment in the absence of direct and distributed ENM release to soil. Increased ENM concentration in water due to atmospheric deposition (wet and dry) is expected as direct ENM release to water diminishes. However, for soluble ENMs dissolution can be the dominant pathway for suspended ENM removal from water even compared to advective transport. For example, simulations for Los Angeles showed that dry deposition, rain scavenging, and wind dilution can remove 90% of ENMs from the atmospheric airshed in ~100-230 days, ~2-6 hrs, and ~0.5-2 days, respectively. For the evaluated ENMs (metal, metal oxides, carbon nanotubes (CNT), nanoclays), mass accumulation in the multimedia environment was mostly in the soil and sediment. Additionally, simulation results for TiO2 in Los Angeles demonstrates that the ENM concentrations in air and

  5. Experiences with distributing graphic software between processors

    SciTech Connect

    Hamlin, G.; George, J.E.

    1982-01-01

    Software to aid the distribution and coordination of tasks between different processors was developed to distribute applications written in Fortran. This development led to the discovery of problems unique to Fortran and to interesting practical solutions. Two graphical applications were distributed to a variety of machines and machine pairs: CDC 7600-LSI/11, CRAY-LSI/11, VAX 11/780, and Apollo. These distributions pointed out several parameters such as the use of Fortran COMMON, communication parameters, and processing capabilities that can affect the successful distribution of applications.

  6. Experiences with distributing graphic software between processors

    SciTech Connect

    Hamlin, G.; George, J.E.

    1982-01-01

    Software to aid the distribution and coordination of tasks between different processors was developed to distribute applications written in Fortran. This development led to the discovery of problems unique to Fortran and to interesting practical solutions. Two graphical applications were distributed to a variety of machines and machine pairs: CDC 7600-LSI/11, Cray-LSI/11, VAX 11/780, and Apollo. These distributions pointed out several parameters such as the use of Fortran Common, communication parameters, and processing capabilities that can affect the successful distribution of applications.

  7. Diffraction Theory and Almost Periodic Distributions

    NASA Astrophysics Data System (ADS)

    Strungaru, Nicolae; Terauds, Venta

    2016-09-01

    We introduce and study the notions of translation bounded tempered distributions, and autocorrelation for a tempered distribution. We further introduce the spaces of weakly, strongly and null weakly almost periodic tempered distributions and show that for weakly almost periodic tempered distributions the Eberlein decomposition holds. For translation bounded measures all these notions coincide with the classical ones. We show that tempered distributions with measure Fourier transform are weakly almost periodic and that for this class, the Eberlein decomposition is exactly the Fourier dual of the Lebesgue decomposition, with the Fourier-Bohr coefficients specifying the pure point part of the Fourier transform. We complete the project by looking at few interesting examples.

  8. Positive phase space distributions and uncertainty relations

    NASA Technical Reports Server (NTRS)

    Kruger, Jan

    1993-01-01

    In contrast to a widespread belief, Wigner's theorem allows the construction of true joint probabilities in phase space for distributions describing the object system as well as for distributions depending on the measurement apparatus. The fundamental role of Heisenberg's uncertainty relations in Schroedinger form (including correlations) is pointed out for these two possible interpretations of joint probability distributions. Hence, in order that a multivariate normal probability distribution in phase space may correspond to a Wigner distribution of a pure or a mixed state, it is necessary and sufficient that Heisenberg's uncertainty relation in Schroedinger form should be satisfied.

  9. Efficient Session Type Guided Distributed Interaction

    NASA Astrophysics Data System (ADS)

    Sivaramakrishnan, K. C.; Nagaraj, Karthik; Ziarek, Lukasz; Eugster, Patrick

    Recently, there has been much interest in multi-party session types (MPSTs) as a means of rigorously specifying protocols for interaction among multiple distributed participants. By capturing distributed interaction as series of typed interactions, MPSTs allow for the static verification of compliance of corresponding distributed object programs. We observe that explicit control flow information manifested by MPST opens intriguing avenues also for performance enhancements. In this paper, we present a session type assisted performance enhancement framework for distributed object interaction in Java. Experimental evaluation within our distributed runtime infrastructure illustrates the costs and benefits of our composable enhancement strategies.

  10. Graviton scattering and matter distribution.

    PubMed

    Britten, R J

    1992-05-01

    In this model gravitation results from the emission and absorption of quanta (gravitons) that are scattered a few times in crossing a typical galaxy. Many features of the universe can be explained in terms of this model, although theoretical justification for the scattering of gravitons is lacking. Gravitons follow a random walk and diffuse through the outer regions of a galaxy. As a result the force of attraction follows a 1/R law, matching observed galactic rotation curves and explaining galactic dynamics without the need of dark matter. The model makes predictions regarding early stages in the expansion of the universe and the establishment of the mass distribution. It may be assumed that a nearly uniform expanding cloud of gas was present that was subject to collapse under gravitational forces. The 1/R law of attraction due to graviton diffusion is orders of magnitude more effective for initiation of collapse than the inverse square law, and it applies to blocks of gas larger than the graviton mean free path. Delay in the spread of gravitational attraction by diffusion sets a time-dependent range beyond which the attractive force is zero. In the model this causes arrays of matter to collapse locally into zones with a spacing set by the length of the range of the attractive force. An initial examination indicates that under these conditions the background radiation could have been released from a nearly uniform distribution at the time of decoupling of radiation and matter, followed by gravitational collapse into blocks of galactic mass. In the model the diffusion of gravitons continued and collapse became possible on a larger scale, initiating the formation of galactic clusters and still larger structures. The slow rate of diffusion then prevented the largest structures from attracting each other and permitted the formation of the voids on a very large scale. The model predicts that on the largest scale there is a three-dimensional repeated array of structures

  11. Statistics of the galaxy distribution

    NASA Astrophysics Data System (ADS)

    Lachièze-Rey, Marc

    1989-09-01

    The universe appears from recent observational results to be a highly structured but also highly disordered medium. This accounts for the difficulties with a conventional statistical approach. Since the statistics of disordered media is an increasingly well-studied field in physics, it is tempting to try to adapt its methods for the study of the universe (the use of correlation functions also resulted from the adaptation of techniques from a very different field to astrophysics). This is already the case for the fractal analysis, which, mainly developed in microscopic statistics, is increasingly used in astrophysics. I suggest a new approach, also derived from the study of disordered media, both from the study of percolation clusters and from the dynamics of so-called “cluster aggregation” gelification models. This approach is briefly presented. Its main interest lies in two points. First, it suggests an analysis able to characterize features of unconventional statistics (those that seem to be present in the galaxy distribution and which conventional indicators are unable to take into account). It appears also a priori very convenient for a synthetic approach, since it can be related to the other indicators used up to now: the link with the void probability function is very straightforward. The connexion with fractals can be said to be contained in the method, since the objects defined during this analysis are themselves fractal: different kinds of fractal dimensions are very easy to extract from the analysis. The link with the percolation studies is also very natural since the method is adapted from the study of percolation clusters. It is also expected that the information concerning the topology is contained in this approach; this seems natural since the method is very sensitive to the topology of the distribution and posses some common characteristics with the topology analysis already developed by Gott et al. (1986). The quantitative relations remain

  12. Protection of Active Distribution Systems with DGs

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  13. Bernstein instability driven by thermal ring distribution

    SciTech Connect

    Yoon, Peter H.; Hadi, Fazal; Qamar, Anisa

    2014-07-15

    The classic Bernstein waves may be intimately related to banded emissions detected in laboratory plasmas, terrestrial, and other planetary magnetospheres. However, the customary discussion of the Bernstein wave is based upon isotropic thermal velocity distribution function. In order to understand how such waves can be excited, one needs an emission mechanism, i.e., an instability. In non-relativistic collision-less plasmas, the only known Bernstein wave instability is that associated with a cold perpendicular velocity ring distribution function. However, cold ring distribution is highly idealized. The present Brief Communication generalizes the cold ring distribution model to include thermal spread, so that the Bernstein-ring instability is described by a more realistic electron distribution function, with which the stabilization by thermal spread associated with the ring distribution is demonstrated. The present findings imply that the excitation of Bernstein waves requires a sufficiently high perpendicular velocity gradient associated with the electron distribution function.

  14. Influence of breakup on fusion barrier distributions

    NASA Astrophysics Data System (ADS)

    Patel, D.; Nayak, B. K.; Mukherjee, S.; Biswas, D. C.; Mirgule, E. T.; John, B. V.; Gupta, Y. K.; Mukhopadhyay, S.; Prajapati, G.; Danu, L. S.; Rath, P. K.; Desai, V.; Deshmukh, N.; Saxena, A.

    2013-04-01

    Fusion barrier distributions have been extracted from the quasi-elastic scattering excitation functions, measured at backward angle θlab = 160° in reactions of 6,7Li+209Bi. The present results have been compared with the barrier distributions obtained from the fusion excitation function measurements for the above mentioned systems. The fusion barrier distributions from the quasi-elastic scattering excitation functions have been analyzed with simplified Coupled Channels calculations using Fresco. Inclusions of resonant states for both 6,7Li projectiles improve the predictions to describe the measured quasi-elastic scattering excitation functions and barrier distributions. For both the reactions peak positions of fusion barrier distributions are shifted towards a lower energy side in comparison to that obtained from the fusion excitation function measurements. The observed discrepancy in peak positions of barrier distributions obtained from quasi-elastic scattering and fusion excitation function measurements has been discussed in terms of total reaction threshold distribution.

  15. Hierarchical model for distributed seismicity

    SciTech Connect

    Tejedor, Alejandro; Gomez, Javier B.; Pacheco, Amalio F.

    2010-07-15

    A cellular automata model for the interaction between seismic faults in an extended region is presented. Faults are represented by boxes formed by a different number of sites and located in the nodes of a fractal tree. Both the distribution of box sizes and the interaction between them is assumed to be hierarchical. Load particles are randomly added to the system, simulating the action of external tectonic forces. These particles fill the sites of the boxes progressively. When a box is full it topples, some of the particles are redistributed to other boxes and some of them are lost. A box relaxation simulates the occurrence of an earthquake in the region. The particle redistributions mostly occur upwards (to larger faults) and downwards (to smaller faults) in the hierarchy producing new relaxations. A simple and efficient bookkeeping of the information allows the running of systems with more than fifty million faults. This model is consistent with the definition of magnitude, i.e., earthquakes of magnitude m take place in boxes with a number of sites ten times bigger than those boxes responsible for earthquakes with a magnitude m-1 which are placed in the immediate lower level of the hierarchy. The three parameters of the model have a geometrical nature: the height or number of levels of the fractal tree, the coordination of the tree and the ratio of areas between boxes in two consecutive levels. Besides reproducing several seismicity properties and regularities, this model is used to test the performance of some precursory patterns.

  16. Distributed consensus on camera pose.

    PubMed

    Jorstad, Anne; DeMenthon, Daniel; Wang, I-Jeng; Burlina, Philippe

    2010-09-01

    Our work addresses pose estimation in a distributed camera framework. We examine how processing cameras can best reach a consensus about the pose of an object when they are each given a model of the object, defined by a set of point coordinates in the object frame of reference. The cameras can only see a subset of the object feature points in the midst of background clutter points, not knowing which image points match with which object points, nor which points are object points or background points. The cameras individually recover a prediction of the object's pose using their knowledge of the model, and then exchange information with their neighbors, performing consensus updates locally to obtain a single estimate consistent across all cameras, without requiring a common centralized processor. Our main contributions are: 1) we present a novel algorithm performing consensus updates in 3-D world coordinates penalized by a 3-D model, and 2) we perform a thorough comparison of our method with other current consensus methods. Our method is consistently the most accurate, and we confirm that the existing consensus method based upon calculating the Karcher mean of rotations is also reliable and fast. Experiments on simulated and real imagery are reported. PMID:20363678

  17. Monitoring the DIRAC distributed system

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

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

  18. Multimedia Environmental Distribution of Nanomaterials

    NASA Astrophysics Data System (ADS)

    Liu, Haoyang Haven

    Engineered nanomaterials (ENMs), which may be released to the environment due to human-related activities, can move across environmental phase boundaries and be found in most media. Given the rapid development and growing applications of nanotechnology, there is concern and thus the need to assess the potential environmental impact associated with ENMs. Accordingly, a modeling platform was developed to enable evaluation of the dynamic multimedia environmental distribution of ENMs (MendNano) and the range of potential exposure concentrations of ENMs. The MendNano was based on a dynamic multimedia compartmental modeling approach that was guided by detailed analysis of the agglomeration of ENMs, life-cycle analysis based estimates of their potential release to the environment, and incorporation of mechanistic sub-models of various intermedia transport processes. Model simulations for various environmental scenarios indicated that ENM accumulation in the sediment increased significantly with increased ENMs attachment to suspended solids in water. Atmospheric dry and wet depositions can be important pathways for ENMs input to the terrestrial environment in the absence of direct and distributed ENM release to soil. Increased ENM concentration in water due to atmospheric deposition (wet and dry) is expected as direct ENM release to water diminishes. However, for soluble ENMs dissolution can be the dominant pathway for suspended ENM removal from water even compared to advective transport. For example, simulations for Los Angeles showed that dry deposition, rain scavenging, and wind dilution can remove 90% of ENMs from the atmospheric airshed in ~100-230 days, ~2-6 hrs, and ~0.5-2 days, respectively. For the evaluated ENMs (metal, metal oxides, carbon nanotubes (CNT), nanoclays), mass accumulation in the multimedia environment was mostly in the soil and sediment. Additionally, simulation results for TiO2 in Los Angeles demonstrates that the ENM concentrations in air and

  19. Distributed Seams for Gigapixel Panoramas.

    PubMed

    Philip, Sujin; Summa, Brian; Tierny, Julien; Bremer, Peer-Timo; Pascucci, Valerio

    2015-03-01

    Gigapixel panoramas are an increasingly popular digital image application. They are often created as a mosaic of many smaller images. The mosaic acquisition can take many hours causing the individual images to differ in exposure and lighting conditions. A blending operation is often necessary to give the appearance of a seamless image. The blending quality depends on the magnitude of discontinuity along the image boundaries. Often, new boundaries, or seams, are first computed that minimize this transition. Current techniques based on multi-labeling Graph Cuts are too slow and memory intensive for gigapixel sized panoramas. In this paper, we present a parallel, out-of-core seam computing technique that is fast, has small memory footprint, and is capable of running efficiently on different types of parallel systems. Its maximum memory usage is configurable, in the form of a cache, which can improve performance by reducing redundant disk I/O and computations. It shows near-perfect scaling on symmetric multiprocessing systems and good scaling on clusters and distributed shared memory systems. Our technique improves the time required to compute seams for gigapixel imagery from many hours (or even days) to just a few minutes, while still producing boundaries with energy that is on-par with Graph Cuts. PMID:26357067

  20. The compositional distribution of asteroids

    NASA Astrophysics Data System (ADS)

    DeMeo, F.; Carry, B.; Alexander, C.; Walsh, K.; Chapman, C.

    2014-07-01

    Each compositional class of asteroid is a relic of the temperature and composition conditions in which it formed. The current distribution reveals the history of the Solar System, and each body acts as a marker of any mixing that occurred since formation. The remnant of a primordial temperature gradient, seen as transition from the S class to C class dominating in different regions of the asteroid belt has been a paradigm for three decades [1-4]. Today, we are armed with major advancements from the past decade that have revolutionized the field of asteroids in areas such as discovery, physical characterization, and dynamical models. A new and more detailed compositional map [5,6] created with data from the Sloan Digital Sky Survey [7] allows us to re-examine compositional trends in the main asteroid belt and what the physical and dynamical implications might be. This talk is related to recent work from DeMeo & Carry 2013, 2014 [5,6] and an upcoming chapter of the "Asteroids IV" book in 2015.

  1. Distributed data transfers in CMS

    NASA Astrophysics Data System (ADS)

    Magini, Nicolo; Ratnikova, Natalia; Rossman, Paul; Sánchez-Hernández, Alberto; Wildish, Tony

    2011-12-01

    The multi-tiered computing infrastructure of the CMS experiment at the LHC depends on the reliable and fast transfer of data between the different CMS computing sites. Data have to be transferred from the Tier-0 to the Tier-l sites for archival in a timely manner to avoid overflowing disk buffers at CERN. Data have to be transferred in bursts to all Tier-2 level sites for analysis as well as synchronized between the different Tier-l sites. The data transfer system is the key ingredient which enables the optimal usage of all distributed resources. The operation of the transfer system consists of monitoring and debugging of transfer issues to guarantee a timely delivery of data to all corners of the CMS computing infrastructure. Further task of transfer operation is to guarantee the consistency of the data at all sites, both on disk and on tape. Procedures to verify the consistency and to debug and repair problems will be discussed.

  2. Low jitter RF distribution system

    SciTech Connect

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

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

  3. Microflare Statistics and Frequency Distribution

    NASA Astrophysics Data System (ADS)

    Christe, S. D.; Hannah, I.; Rauscher, E.; Krucker, S.; McTiernan, J.; Lin, R. P.

    2005-05-01

    RHESSI is uniquely suited to observe solar microflares due to its unique sensitivity in the 3-15 keV energy range (up to ~100 times better than previous solar instruments). As such, it provides new information on these low level transients. Initial results (Krucker et al 2002, Benz & Grigis 2002) suggest that microflares are different from larger flares. They are more often associated with steep nonthermal spectra (power law index -5 to -7). In this study, we present microflare statistics from times of low activity. A list of microflares was created by applying the standard RHESSI flare-finding algorithm to the lower 6-12 keV energy range (~10,000 events). Imaging was used in order to obtain positions of solar events and reject non-solar events. These solar events were then each spectrally analyzed. We present microflare statistics, including active region productivity, and the microflare frequency distribution. This work was supported by NASA contract NAS5-98033.

  4. Organizing Diverse, Distributed Project Information

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.

    2003-01-01

    SemanticOrganizer is a software application designed to organize and integrate information generated within a distributed organization or as part of a project that involves multiple, geographically dispersed collaborators. SemanticOrganizer incorporates the capabilities of database storage, document sharing, hypermedia navigation, and semantic-interlinking into a system that can be customized to satisfy the specific information-management needs of different user communities. The program provides a centralized repository of information that is both secure and accessible to project collaborators via the World Wide Web. SemanticOrganizer's repository can be used to collect diverse information (including forms, documents, notes, data, spreadsheets, images, and sounds) from computers at collaborators work sites. The program organizes the information using a unique network-structured conceptual framework, wherein each node represents a data record that contains not only the original information but also metadata (in effect, standardized data that characterize the information). Links among nodes express semantic relationships among the data records. The program features a Web interface through which users enter, interlink, and/or search for information in the repository. By use of this repository, the collaborators have immediate access to the most recent project information, as well as to archived information. A key advantage to SemanticOrganizer is its ability to interlink information together in a natural fashion using customized terminology and concepts that are familiar to a user community.

  5. The learnability of critical distributions

    NASA Astrophysics Data System (ADS)

    Schwab, David; Torrence, Johannah; Torlai, Giacomo; Melko, Roger; Palmer, Stephanie

    Many biological systems, including some neural population codes, have been shown empirically to sit near a critical point. Here we study the learnability of such codes. We first construct networks of interacting binary neurons with random, sparse interactions (i.e. a Erdos-Renyi graph) of uniform strength. We then characterize the discriminability of those interactions from data samples by performing a direct coupling analysis and thresholding the direct information between each pair of neurons to predict the presence or absence of an interaction. By sweeping through threshold values, we compute the area under the ROC curve as a measure of discriminability of the interactions. We show that the resulting discriminability is maximized when the original distribution is at its critical point. We next trained deep neural networks to discriminate between samples drawn from two nearby temperatures in the 2D Ising model. We find distinct signatures of decoding performance in the vicinity of the critical point. This technique may be useful for detecting phase transitions in models without an a priori identified order parameter.

  6. 26 CFR 1.963-3 - Distributions counting toward a minimum distribution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 10 2011-04-01 2011-04-01 false Distributions counting toward a minimum distribution. 1.963-3 Section 1.963-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... Distributions counting toward a minimum distribution. (a) Conditions under which earnings and profits...

  7. 13 CFR 107.1560 - Distributions by Licensee-required Distributions to private investors and SBA.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Distributions to private investors and SBA. 107.1560 Section 107.1560 Business Credit and Assistance SMALL... private investors and SBA. You must make Distributions under this § 107.1560 if you have outstanding... Distribution: (1) All Distributions to private investors reduce Retained Earnings Available for...

  8. 13 CFR 107.1560 - Distributions by Licensee-required Distributions to private investors and SBA.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Distributions to private investors and SBA. 107.1560 Section 107.1560 Business Credit and Assistance SMALL... private investors and SBA. You must make Distributions under this § 107.1560 if you have outstanding... Distribution: (1) All Distributions to private investors reduce Retained Earnings Available for...

  9. 13 CFR 107.1560 - Distributions by Licensee-required Distributions to private investors and SBA.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Distributions to private investors and SBA. 107.1560 Section 107.1560 Business Credit and Assistance SMALL... private investors and SBA. You must make Distributions under this § 107.1560 if you have outstanding... Distribution: (1) All Distributions to private investors reduce Retained Earnings Available for...

  10. 13 CFR 107.1560 - Distributions by Licensee-required Distributions to private investors and SBA.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Distributions to private investors and SBA. 107.1560 Section 107.1560 Business Credit and Assistance SMALL... private investors and SBA. You must make Distributions under this § 107.1560 if you have outstanding... Distribution: (1) All Distributions to private investors reduce Retained Earnings Available for...

  11. A Survey on Distributed File System Technology

    NASA Astrophysics Data System (ADS)

    Blomer, J.

    2015-05-01

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

  12. Global Distribution of Pyrogenic Carbon

    NASA Astrophysics Data System (ADS)

    Reisser, Moritz; Abiven, Samuel; Schmidt, Michael W. I.

    2016-04-01

    Pyrogenic Carbon (PyC) is ubiquitous in the environment and represents presumably one of the most stable compounds of the total organic carbon. Due to its persistence in the soil, it might play an important role in the global carbon cycle. In order to model future CO2 emissions from soils it is thus crucial to know where and how much of PyC exists on a global scale. Yet, only rough estimates for global PyC stocks in soils could be made, and even less is known about the distribution across ecosystems. Therefore we propose here literature analysis of data on PyC concentrations and stocks worldwide. We extracted PyC values in soils from the literature (n = 600) and analysed the percentage of PyC in the soil organic carbon (SOC) as a function of climate (temperature, precipitation), soil parameters (pH, clay content), fire characteristics (fire frequency and fire regime) and land use. Overall, the average contribution of PyC to SOC was 13 %, ranging from 0.1 % up to 60 %. We observed that the PyC content was significantly higher with high clay content, higher pH, and in cultivated land as compared to forest and grassland. We did not observe any relationships between fire activity, frequency or intensity and PyC % at a global scale. When the fire regime was monitored on site (only 12 % of the data we collected), we observed higher PyC concentrations with higher fire frequencies. We hypothesise that the resolution of global fire datasets is neither temporally nor spatially high enough to explain the very local fire history of the soil samples. Data points were not homogeneously distributed on the globe, but rather aggregated in places like Central Europe, the Russian Steppe or North America. Therefore, a global interpolation is not directly possible. We modelled PyC concentrations, based on the five most significant parameters, which were clay content, pH, mean annual temperature and precipitation as well as land use. We then predicted worldwide PyC using global datasets

  13. Sample-Based Vegetation Distribution Information Synthesis.

    PubMed

    Xu, Chanchan; Yang, Gang; Yang, Meng

    2015-01-01

    In constructing and visualizing a virtual three-dimensional forest scene, we must first obtain the vegetation distribution, namely, the location of each plant in the forest. Because the forest contains a large number of plants, the distribution of each plant is difficult to obtain from actual measurement methods. Random approaches are used as common solutions to simulate a forest distribution but fail to reflect the specific biological arrangements among types of plants. Observations show that plants in the forest tend to generate particular distribution patterns due to growth competition and specific habitats. This pattern, which represents a local feature in the distribution and occurs repeatedly in the forest, is in line with the "locality" and "static" characteristics in the "texture data", making it possible to use a sample-based texture synthesis strategy to build the distribution. We propose a vegetation distribution data generation method that uses sample-based vector pattern synthesis. A sample forest stand is obtained first and recorded as a two-dimensional vector-element distribution pattern. Next, the large-scale vegetation distribution pattern is synthesized automatically using the proposed vector pattern synthesis algorithm. The synthesized distribution pattern resembles the sample pattern in the distribution features. The vector pattern synthesis algorithm proposed in this paper adopts a neighborhood comparison technique based on histogram matching, which makes it efficient and easy to implement. Experiments show that the distribution pattern synthesized with this method can sufficiently preserve the features of the sample distribution pattern, making our method meaningful for constructing realistic forest scenes. PMID:26252952

  14. Non-Gaussian Photon Probability Distribution

    NASA Astrophysics Data System (ADS)

    Solomon, Benjamin T.

    2010-01-01

    This paper investigates the axiom that the photon's probability distribution is a Gaussian distribution. The Airy disc empirical evidence shows that the best fit, if not exact, distribution is a modified Gamma mΓ distribution (whose parameters are α = r, βr/√u ) in the plane orthogonal to the motion of the photon. This modified Gamma distribution is then used to reconstruct the probability distributions along the hypotenuse from the pinhole, arc from the pinhole, and a line parallel to photon motion. This reconstruction shows that the photon's probability distribution is not a Gaussian function. However, under certain conditions, the distribution can appear to be Normal, thereby accounting for the success of quantum mechanics. This modified Gamma distribution changes with the shape of objects around it and thus explains how the observer alters the observation. This property therefore places additional constraints to quantum entanglement experiments. This paper shows that photon interaction is a multi-phenomena effect consisting of the probability to interact Pi, the probabilistic function and the ability to interact Ai, the electromagnetic function. Splitting the probability function Pi from the electromagnetic function Ai enables the investigation of the photon behavior from a purely probabilistic Pi perspective. The Probabilistic Interaction Hypothesis is proposed as a consistent method for handling the two different phenomena, the probability function Pi and the ability to interact Ai, thus redefining radiation shielding, stealth or cloaking, and invisibility as different effects of a single phenomenon Pi of the photon probability distribution. Sub wavelength photon behavior is successfully modeled as a multi-phenomena behavior. The Probabilistic Interaction Hypothesis provides a good fit to Otoshi's (1972) microwave shielding, Schurig et al. (2006) microwave cloaking, and Oulton et al. (2008) sub wavelength confinement; thereby providing a strong case that

  15. Sample-Based Vegetation Distribution Information Synthesis

    PubMed Central

    Xu, Chanchan; Yang, Gang; Yang, Meng

    2015-01-01

    In constructing and visualizing a virtual three-dimensional forest scene, we must first obtain the vegetation distribution, namely, the location of each plant in the forest. Because the forest contains a large number of plants, the distribution of each plant is difficult to obtain from actual measurement methods. Random approaches are used as common solutions to simulate a forest distribution but fail to reflect the specific biological arrangements among types of plants. Observations show that plants in the forest tend to generate particular distribution patterns due to growth competition and specific habitats. This pattern, which represents a local feature in the distribution and occurs repeatedly in the forest, is in line with the “locality” and “static” characteristics in the “texture data”, making it possible to use a sample-based texture synthesis strategy to build the distribution. We propose a vegetation distribution data generation method that uses sample-based vector pattern synthesis. A sample forest stand is obtained first and recorded as a two-dimensional vector-element distribution pattern. Next, the large-scale vegetation distribution pattern is synthesized automatically using the proposed vector pattern synthesis algorithm. The synthesized distribution pattern resembles the sample pattern in the distribution features. The vector pattern synthesis algorithm proposed in this paper adopts a neighborhood comparison technique based on histogram matching, which makes it efficient and easy to implement. Experiments show that the distribution pattern synthesized with this method can sufficiently preserve the features of the sample distribution pattern, making our method meaningful for constructing realistic forest scenes. PMID:26252952

  16. A distributed program composition system

    NASA Technical Reports Server (NTRS)

    Brown, Robert L.

    1989-01-01

    A graphical technique for creating distributed computer programs is investigated and a prototype implementation is described which serves as a testbed for the concepts. The type of programs under examination is restricted to those comprising relatively heavyweight parts that intercommunicate by passing messages of typed objects. Such programs are often presented visually as a directed graph with computer program parts as the nodes and communication channels as the edges. This class of programs, called parts-based programs, is not well supported by existing computer systems; much manual work is required to describe the program to the system, establish the communication paths, accommodate the heterogeneity of data types, and to locate the parts of the program on the various systems involved. The work described solves most of these problems by providing an interface for describing parts-based programs in this class in a way that closely models the way programmers think about them: using sketches of diagraphs. Program parts, the computational modes of the larger program system are categorized in libraries and are accessed with browsers. The process of programming has the programmer draw the program graph interactively. Heterogeneity is automatically accommodated by the insertion of type translators where necessary between the parts. Many decisions are necessary in the creation of a comprehensive tool for interactive creation of programs in this class. Possibilities are explored and the issues behind such decisions are presented. An approach to program composition is described, not a carefully implemented programming environment. However, a prototype implementation is described that can demonstrate the ideas presented.

  17. Security of Quantum Key Distribution

    NASA Astrophysics Data System (ADS)

    Lütkenhaus, Norbert

    2007-03-01

    Quantum Key Distribution (QKD) is the most advanced application of Quantum Information Science. It allows extending secret keys over some distances in such a way that the security of the resulting key material can be guaranteed by the laws of quantum mechanics. In contrast to presently used encryption techniques, the security of QKD can be proven in terms of information-theoretic measures. The resulting key can then be used for many tasks, including exchanging secret messages. QKD has been developed in the language of abstract two-level systems, the qubits. They cannot be easily implemented in optical signals. It took some time to bring the protocols and theory of QKD to the point where they fit to the realities of fiber-optical or free-space applications, including lossy channels. Today, QKD schemes can be implemented reliably using standard off-the-shelf components. Information theoretic security is a theoretical concept. Naturally, it is impossible to demonstrate directly that a given experimental set-up indeed creates a secret key. What one can do is to show that the experiment can give data within a certain parameters regime, such as error rate and loss rate, for which a security proof exists. I will discuss what parameter regime gives provable secure key and which parameter regime cannot lead to secret key. It is desirable to prove `unconditional security,' as it is termed in the world of classical cryptography: no assumption is made about the attacks of an eavesdropper on the quantum channel. However, one has to assume that the signal structure and the measurement device are correctly described by the adopted model and that no eavesdropper can intrude the sender or receiver unit. In this talk I will briefly introduce the concept of QKD and optical implementations. Especially I will discuss security aspects of modern approaches of QKD schemes that allow us to increase the covered distance and the achievable rate.

  18. Hierarchical model for distributed seismicity.

    PubMed

    Tejedor, Alejandro; Gómez, Javier B; Pacheco, Amalio F

    2010-07-01

    A cellular automata model for the interaction between seismic faults in an extended region is presented. Faults are represented by boxes formed by a different number of sites and located in the nodes of a fractal tree. Both the distribution of box sizes and the interaction between them is assumed to be hierarchical. Load particles are randomly added to the system, simulating the action of external tectonic forces. These particles fill the sites of the boxes progressively. When a box is full it topples, some of the particles are redistributed to other boxes and some of them are lost. A box relaxation simulates the occurrence of an earthquake in the region. The particle redistributions mostly occur upwards (to larger faults) and downwards (to smaller faults) in the hierarchy producing new relaxations. A simple and efficient bookkeeping of the information allows the running of systems with more than fifty million faults. This model is consistent with the definition of magnitude, i.e., earthquakes of magnitude m take place in boxes with a number of sites ten times bigger than those boxes responsible for earthquakes with a magnitude m-1 which are placed in the immediate lower level of the hierarchy. The three parameters of the model have a geometrical nature: the height or number of levels of the fractal tree, the coordination of the tree and the ratio of areas between boxes in two consecutive levels. Besides reproducing several seismicity properties and regularities, this model is used to test the performance of some precursory patterns. PMID:20866700

  19. Bilateral Trade Flows and Income Distribution Similarity

    PubMed Central

    2016-01-01

    Current models of bilateral trade neglect the effects of income distribution. This paper addresses the issue by accounting for non-homothetic consumer preferences and hence investigating the role of income distribution in the context of the gravity model of trade. A theoretically justified gravity model is estimated for disaggregated trade data (Dollar volume is used as dependent variable) using a sample of 104 exporters and 108 importers for 1980–2003 to achieve two main goals. We define and calculate new measures of income distribution similarity and empirically confirm that greater similarity of income distribution between countries implies more trade. Using distribution-based measures as a proxy for demand similarities in gravity models, we find consistent and robust support for the hypothesis that countries with more similar income-distributions trade more with each other. The hypothesis is also confirmed at disaggregated level for differentiated product categories. PMID:27137462

  20. Langevin granulometry of the particle size distribution

    NASA Astrophysics Data System (ADS)

    Kákay, Attila; Gutowski, M. W.; Takacs, L.; Franco, V.; Varga, L. K.

    2004-06-01

    The problem of deriving the particle size distribution directly from superparamagnetic magnetization curves is studied by three mathematical methods: (1) least-squares deviation with regularization procedure, (2) simulated annealing and (3) genetic algorithm. Software has been developed for the latest versions of all these methods and its performance compared for various models of underlying particle size distributions (Dirac dgr-like, lognormal- and Gaussian-shaped). For single peak distributions all three methods give reasonable and similar results, but for bimodal distributions the genetic algorithm is the only acceptable one. The genetic algorithm is able to recover with the same precision both the lognormal and Gaussian single and double (mixed) model distributions. The sensitivity of the genetic algorithm—the most promising method—to uncertainty of measurements was also tested; correct peak position and its half width were recovered for Gaussian distributions, when the analysed data were contaminated with noise of up to 5% of MS.

  1. Electron butterfly distribution modulation by magnetosonic waves

    NASA Astrophysics Data System (ADS)

    Maldonado, Armando A.; Chen, Lunjin; Claudepierre, Seth G.; Bortnik, Jacob; Thorne, Richard M.; Spence, Harlan

    2016-04-01

    The butterfly pitch angle distribution is observed as a dip in an otherwise normal distribution of electrons centered about αeq=90°. During storm times, the formation of the butterfly distribution on the nightside magnetosphere has been attributed to L shell splitting combined with magnetopause shadowing and strong positive radial flux gradients. It has been shown that this distribution can be caused by combined chorus and magnetosonic wave scattering where the two waves work together but at different local times. Presented in our study is an event on 21 August 2013, using Van Allen Probe measurements, where a butterfly distribution formation is modulated by local magnetosonic coherent magnetosonic waves intensity. Transition from normal to butterfly distributions coincides with rising magnetosonic wave intensity while an opposite transition occurs when wave intensity diminishes. We propose that bounce resonance with waves is the underlying process responsible for such rapid modulation, which is confirmed by our test particle simulation.

  2. Bilateral Trade Flows and Income Distribution Similarity.

    PubMed

    Martínez-Zarzoso, Inmaculada; Vollmer, Sebastian

    2016-01-01

    Current models of bilateral trade neglect the effects of income distribution. This paper addresses the issue by accounting for non-homothetic consumer preferences and hence investigating the role of income distribution in the context of the gravity model of trade. A theoretically justified gravity model is estimated for disaggregated trade data (Dollar volume is used as dependent variable) using a sample of 104 exporters and 108 importers for 1980-2003 to achieve two main goals. We define and calculate new measures of income distribution similarity and empirically confirm that greater similarity of income distribution between countries implies more trade. Using distribution-based measures as a proxy for demand similarities in gravity models, we find consistent and robust support for the hypothesis that countries with more similar income-distributions trade more with each other. The hypothesis is also confirmed at disaggregated level for differentiated product categories. PMID:27137462

  3. Radial particle distributions in PARMILA simulation beams

    SciTech Connect

    Boicourt, G.P.

    1984-03-01

    The estimation of beam spill in particle accelerators is becoming of greater importance as higher current designs are being funded. To the present, no numerical method for predicting beam-spill has been available. In this paper, we present an approach to the loss-estimation problem that uses probability distributions fitted to particle-simulation beams. The properties of the PARMILA code's radial particle distribution are discussed, and a broad class of probability distributions are examined to check their ability to fit it. The possibility that the PARMILA distribution is a mixture is discussed, and a fitting distribution consisting of a mixture of two generalized gamma distributions is found. An efficient algorithm to accomplish the fit is presented. Examples of the relative prediction of beam spill are given. 26 references, 18 figures, 1 table.

  4. Computer security in DOE distributed computing systems

    SciTech Connect

    Hunteman, W.J.

    1990-01-01

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

  5. A maximum entropy framework for nonexponential distributions

    PubMed Central

    Peterson, Jack; Dixit, Purushottam D.; Dill, Ken A.

    2013-01-01

    Probability distributions having power-law tails are observed in a broad range of social, economic, and biological systems. We describe here a potentially useful common framework. We derive distribution functions for situations in which a “joiner particle” k pays some form of price to enter a community of size , where costs are subject to economies of scale. Maximizing the Boltzmann–Gibbs–Shannon entropy subject to this energy-like constraint predicts a distribution having a power-law tail; it reduces to the Boltzmann distribution in the absence of economies of scale. We show that the predicted function gives excellent fits to 13 different distribution functions, ranging from friendship links in social networks, to protein–protein interactions, to the severity of terrorist attacks. This approach may give useful insights into when to expect power-law distributions in the natural and social sciences. PMID:24297895

  6. Characterizing maximally singular phase-space distributions

    NASA Astrophysics Data System (ADS)

    Sperling, J.

    2016-07-01

    Phase-space distributions are widely applied in quantum optics to access the nonclassical features of radiations fields. In particular, the inability to interpret the Glauber-Sudarshan distribution in terms of a classical probability density is the fundamental benchmark for quantum light. However, this phase-space distribution cannot be directly reconstructed for arbitrary states, because of its singular behavior. In this work, we perform a characterization of the Glauber-Sudarshan representation in terms of distribution theory. We address important features of such distributions: (i) the maximal degree of their singularities is studied, (ii) the ambiguity of representation is shown, and (iii) their dual space for nonclassicality tests is specified. In this view, we reconsider the methods for regularizing the Glauber-Sudarshan distribution for verifying its nonclassicality. This treatment is supported with comprehensive examples and counterexamples.

  7. Information Theory and the Earth's Density Distribution

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1979-01-01

    An argument for using the information theory approach as an inference technique in solid earth geophysics. A spherically symmetric density distribution is derived as an example of the method. A simple model of the earth plus knowledge of its mass and moment of inertia lead to a density distribution which was surprisingly close to the optimum distribution. Future directions for the information theory approach in solid earth geophysics as well as its strengths and weaknesses are discussed.

  8. Atomic hydrogen distribution. [in Titan atmospheric model

    NASA Technical Reports Server (NTRS)

    Tabarie, N.

    1974-01-01

    Several possible H2 vertical distributions in Titan's atmosphere are considered with the constraint of 5 km-A a total quantity. Approximative calculations show that hydrogen distribution is quite sensitive to two other parameters of Titan's atmosphere: the temperature and the presence of other constituents. The escape fluxes of H and H2 are also estimated as well as the consequent distributions trapped in the Saturnian system.

  9. Analyzing Distributed Processing For Electric Utilities

    NASA Technical Reports Server (NTRS)

    Klein, Stanley A.; Kirkham, Harold; Beardmore, Julie A.

    1990-01-01

    Distributed Processing Trade-Off Model for Electric Utility Operation computer program based upon study performed at California Institute of Technology for NASA's Jet Propulsion Laboratory. Study presented technique addressing question of tradeoffs between expanding communications network or expanding capacity of distributed computers in energy-management systems (EMS) of electric utility. Gives EMS planners macroscopic tool for evaluation of architectures of distributed-processing systems and major technical and economic tradeoffs as well as interactions within systems.

  10. Red cell distribution width and nonalcoholic steatohepatitis

    PubMed Central

    Gulcan Kurt, Yasemin; Cayci, Tuncer; Aydin, Fevzi Nuri; Agilli, Mehmet

    2014-01-01

    Red cell distribution width is a measure of deviation of the volume of red blood cells. It is a marker of anisocytosis and often used to evaluate the possible causes of anemia. Elevated red cell distribution width levels are also associated with acute and chronic inflammatory responses. In nonalcoholic steatohepatitis, inflammation is accompanied with steatosis. For assuming red cell distribution width as a marker of nonalcoholic steatohepatitis, intervening factors such as levels of inflammatory markers should also be evaluated. PMID:25473202

  11. Size distributions of solar energetic particle events

    NASA Technical Reports Server (NTRS)

    Cliver, E.; Reames, D.; Kahler, S.; Cane, H.

    1991-01-01

    NASA particle detectors on the IMP-8 are employed to determine the size distributions of the peak fluxes of events related to solar-energetic particles including protons and electrons. The energetic proton events show a flatter size distribution which suggests that not all flares are proton flares. Both the electron and proton events are classified as either 'impulsive' or 'gradual', and the impulsive events tend to have a steeper power-law distribution.

  12. Intelligent Systems for Power Management and Distribution

    NASA Technical Reports Server (NTRS)

    Button, Robert M.

    2002-01-01

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

  13. Beam expansion with specified final distributions

    SciTech Connect

    Jason, A.J.; Blind, B.; Halbach, K.

    1997-05-09

    The formation of nearly uniformly distributed beams has been accomplished by the use of multipole magnets. Multipole fields, however, are an inappropriate basis for creating precise distributions, particularly since substantial departures from uniformity are produced with a finite number of multipole elements. A more appropriate formalism that allows precise formation of a desired distribution is presented. Design of nonlinear magnets for uniform-beam production and the optics of an accompanying expansion system are presented.

  14. Coal distribution, January--June 1990

    SciTech Connect

    Not Available

    1990-10-17

    The Coal Distribution report provides information on coal production, distribution, and stocks in the United States to a wide audience including Congress, federal and state agencies, the coal industry, and the general public. This issue presents information for January through June 1990. Coal distribution data are shown (in tables 1--34) by coal-producing state of origin, consumer use, method of transportation, and state of destination. 6 figs., 34 tabs.

  15. Particle Size Distributions in Atmospheric Clouds

    NASA Technical Reports Server (NTRS)

    Paoli, Roberto; Shariff, Karim

    2003-01-01

    In this note, we derive a transport equation for a spatially integrated distribution function of particles size that is suitable for sparse particle systems, such as in atmospheric clouds. This is done by integrating a Boltzmann equation for a (local) distribution function over an arbitrary but finite volume. A methodology for evolving the moments of the integrated distribution is presented. These moments can be either tracked for a finite number of discrete populations ('clusters') or treated as continuum variables.

  16. Accuracy analysis of distributed simulation systems

    NASA Astrophysics Data System (ADS)

    Lin, Qi; Guo, Jing

    2010-08-01

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

  17. The role of order in distributed programs

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Marzullo, Keith

    1989-01-01

    The role of order in building distributed systems is discussed. It is the belief that a principle of event ordering underlies the wide range of operating systems mechanisms that were put forward for building robust distributed software. Stated concisely, this principle achieves correct distributed behavior by ordering classes of distributed events that conflict with one another. By focusing on order, simplified descriptions can be obtained and convincingly correct solutions to problems that might otherwise have looked extremely complex. Moreover, it is observed that there are a limited number of ways to obtain order, and that the choice made impacts greatly on performance.

  18. The shape of terrestrial abundance distributions.

    PubMed

    Alroy, John

    2015-09-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood-related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the "double geometric." Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  19. Distributed memory compiler design for sparse problems

    NASA Technical Reports Server (NTRS)

    Wu, Janet; Saltz, Joel; Berryman, Harry; Hiranandani, Seema

    1991-01-01

    A compiler and runtime support mechanism is described and demonstrated. The methods presented are capable of solving a wide range of sparse and unstructured problems in scientific computing. The compiler takes as input a FORTRAN 77 program enhanced with specifications for distributing data, and the compiler outputs a message passing program that runs on a distributed memory computer. The runtime support for this compiler is a library of primitives designed to efficiently support irregular patterns of distributed array accesses and irregular distributed array partitions. A variety of Intel iPSC/860 performance results obtained through the use of this compiler are presented.

  20. Passive containment cooling water distribution device

    DOEpatents

    Conway, Lawrence E.; Fanto, Susan V.

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using a series of radial guide elements and cascading weir boxes to collect and then distribute the cooling water into a series of distribution areas through a plurality of cascading weirs. The cooling water is then uniformly distributed over the curved surface by a plurality of weir notches in the face plate of the weir box.

  1. Distributed computing and nuclear reactor analysis

    SciTech Connect

    Brown, F.B.; Derstine, K.L.; Blomquist, R.N.

    1994-03-01

    Large-scale scientific and engineering calculations for nuclear reactor analysis can now be carried out effectively in a distributed computing environment, at costs far lower than for traditional mainframes. The distributed computing environment must include support for traditional system services, such as a queuing system for batch work, reliable filesystem backups, and parallel processing capabilities for large jobs. All ANL computer codes for reactor analysis have been adapted successfully to a distributed system based on workstations and X-terminals. Distributed parallel processing has been demonstrated to be effective for long-running Monte Carlo calculations.

  2. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  3. WWW media distribution via Hopwise reliable multicast

    SciTech Connect

    Donnelley, J.E.

    1994-12-01

    Repeated access to WWW pages currently makes inefficient use of available network bandwidth. A Distribution Point Model is proposed where large and relatively static sets of pages (e.g. magazines or other such media) are distributed via bulk multicast to LAN distribution points for local access. Some access control issues are discussed. Hopwise Reliable Multicast (HRM) is proposed to simplify reliable multicast of non real time bulk data between LANs. HRM uses TCP for reliability and flow control on a hop by hop basis throughout a multicast distribution tree created by today`s Internet MBone.

  4. The shape of terrestrial abundance distributions

    PubMed Central

    Alroy, John

    2015-01-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood–related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the “double geometric.” Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  5. Research in Distributed Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  6. Distributed flexoelectric structural sensing: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Hu, S. D.; Li, H.; Tzou, H. S.

    2015-07-01

    "Distributed" sensors are sensitive to spatially distributed structural behaviors, as compared with conventional "discrete" sensors measuring only discrete and local behaviors. The phenomenon of electric polarization induced by strain gradients in solid dielectrics is known as the direct flexoelectric effect. In this study, distributed dynamic sensing using flexoelectric materials is proposed and the flexoelectric signal of distributed flexoelectric sensors laminated on an arbitrary shell structure is defined. Both the open-circuit and the close-circuit models of distributed flexoelectric sensing are developed. An equivalent flexoelectric constant is measured using the proposed open-circuit voltage model. Flexoelectric responses of various locations of a BST beam exhibit consistency and linearity in the case of small deflection. The inferred flexoelectric constant is comparable with the reported maximal coefficient and it also proves that the proposed model is effective to the flexoelectric constant measurement. Distributed sensing behaviors are also experimentally validated on the flexoelectric cantilever beam. Results show that theoretical predictions match well with the experimental results for the fundamental mode. Experiments of distributed sensing signals of beams suggest that distributed flexoelectric sensors are competent to provide the mode shape of strain gradients. Thus, distributed sensing based on the flexoelectric effect is effective to monitoring structural dynamic behaviors.

  7. Helicity and Transversity Distributions at HERMES

    SciTech Connect

    De Nardo, Lara

    2005-02-10

    Results obtained by the HERMES Collaboration for the polarized parton distributions {delta}u, {delta}d, {delta}u-bar, {delta}d-bar, {delta}s extracted from inclusive and semi-inclusive asymmetries on H and D in a LO analysis are presented. The up and down distributions are measured with good precision and are determined to be positive and negative respectively. The sea distributions have been extracted for the first time and the strange sea is consistent with zero within errors.Single spin asymmetries on transversely polarized hydrogen target provide evidence of transversity distributions.

  8. Wigner distribution function in nonlinear optics.

    PubMed

    Dragoman, D

    1996-07-20

    Transformation laws for the Wigner distribution function, the radiant intensity, the radiant emittance, and the first- and second-order moments of the Wigner distribution function through an inhomogeneous, Kerr-type medium have been derived as well as for the beam quality factor and the kurtosis parameter. It is shown that the inhomogeneous Kerr-type medium can be approximated from the Wigner-distribution-function transformation-law point of view with a symplectic ABCD matrix with elements depending on the field distribution. PMID:21102821

  9. Dynamic object management for distributed data structures

    NASA Technical Reports Server (NTRS)

    Totty, Brian K.; Reed, Daniel A.

    1992-01-01

    In distributed-memory multiprocessors, remote memory accesses incur larger delays than local accesses. Hence, insightful allocation and access of distributed data can yield substantial performance gains. The authors argue for the use of dynamic data management policies encapsulated within individual distributed data structures. Distributed data structures offer performance, flexibility, abstraction, and system independence. This approach is supported by data from a trace-driven simulation study of parallel scientific benchmarks. Experimental data on memory locality, message count, message volume, and communication delay suggest that data-structure-specific data management is superior to a single, system-imposed policy.

  10. Classifications and comparisons of multilocus recombination distributions

    PubMed Central

    Karlin, Samuel; Liberman, Uri

    1978-01-01

    Various classifications and representations of multilocus recombination structures are delineated based on generalized notions of linkage values and recombination rates. An important class of recombination distributions (called the count-location chiasma process) is parameterized by a distribution of the number of crossover events and, for each such crossover count, by a conditional distribution of crossover locations. A number of properties of this recombination structure are developed. A multilocus definition of a “natural” recombination range is set forth. Orderings among recombination distributions in the multilocus setting are also discussed. Comparisons are made in terms of complete linkage, free assortment and noninterference schemes serving as standards. PMID:16592601

  11. NASA Constellation Distributed Simulation Middleware Trade Study

    NASA Technical Reports Server (NTRS)

    Hasan, David; Bowman, James D.; Fisher, Nancy; Cutts, Dannie; Cures, Edwin Z.

    2008-01-01

    This paper presents the results of a trade study designed to assess three distributed simulation middleware technologies for support of the NASA Constellation Distributed Space Exploration Simulation (DSES) project and Test and Verification Distributed System Integration Laboratory (DSIL). The technologies are the High Level Architecture (HLA), the Test and Training Enabling Architecture (TENA), and an XML-based variant of Distributed Interactive Simulation (DIS-XML) coupled with the Extensible Messaging and Presence Protocol (XMPP). According to the criteria and weights determined in this study, HLA scores better than the other two for DSES as well as the DSIL.

  12. The WorkPlace distributed processing environment

    NASA Technical Reports Server (NTRS)

    Ames, Troy; Henderson, Scott

    1993-01-01

    Real time control problems require robust, high performance solutions. Distributed computing can offer high performance through parallelism and robustness through redundancy. Unfortunately, implementing distributed systems with these characteristics places a significant burden on the applications programmers. Goddard Code 522 has developed WorkPlace to alleviate this burden. WorkPlace is a small, portable, embeddable network interface which automates message routing, failure detection, and re-configuration in response to failures in distributed systems. This paper describes the design and use of WorkPlace, and its application in the construction of a distributed blackboard system.

  13. Tools for Supporting Distributed Agile Project Planning

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Maurer, Frank; Morgan, Robert; Oliveira, Josyleuda

    Agile project planning plays an important part in agile software development. In distributed settings, project planning is severely impacted by the lack of face-to-face communication and the inability to share paper index cards amongst all meeting participants. To address these issues, several distributed agile planning tools were developed. The tools vary in features, functions and running platforms. In this chapter, we first summarize the requirements for distributed agile planning. Then we give an overview on existing agile planning tools. We also evaluate existing tools based on tool requirements. Finally, we present some practical advices for both designers and users of distributed agile planning tools.

  14. Tools for monitoring and controlling distributed applications

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Wood, Mark D.

    1991-01-01

    The Meta system is a UNIX-based toolkit that assists in the construction of reliable reactive systems, such as distributed monitoring and debugging systems, tool integration systems and reliable distributed applications. Meta provides mechanisms for instrumenting a distributed application and the environment in which it executes, and Meta supplies a service that can be used to monitor and control such an instrumented application. The Meta toolkit is built on top of the ISIS toolkit; they can be used together in order to build fault-tolerant and adaptive, distributed applications.

  15. Reusable and Extensible High Level Data Distributions

    NASA Technical Reports Server (NTRS)

    Diaconescu, Roxana E.; Chamberlain, Bradford; James, Mark L.; Zima, Hans P.

    2005-01-01

    This paper presents a reusable design of a data distribution framework for data parallel high performance applications. We are implementing the design in the context of the Chapel high productivity programming language. Distributions in Chapel are a means to express locality in systems composed of large numbers of processor and memory components connected by a network. Since distributions have a great effect on,the performance of applications, it is important that the distribution strategy can be chosen by a user. At the same time, high productivity concerns require that the user is shielded from error-prone, tedious details such as communication and synchronization. We propose an approach to distributions that enables the user to refine a language-provided distribution type and adjust it to optimize the performance of the application. Additionally, we conceal from the user low-level communication and synchronization details to increase productivity. To emphasize the generality of our distribution machinery, we present its abstract design in the form of a design pattern, which is independent of a concrete implementation. To illustrate the applicability of our distribution framework design, we outline the implementation of data distributions in terms of the Chapel language.

  16. Rank-Size Distribution of Notes in Harmonic Music: Hierarchic Shuffling of Distributions

    NASA Astrophysics Data System (ADS)

    Del Río, Manuel Beltrán; Cocho, Germinal

    We trace the rank size distribution of notes in harmonic music, which on previous works we suggested was much better represented by the Two-parameter, first class Beta distribution than the customary power law, to the ranked mixing of distributions dictated by the harmonic and instrumental nature of the piece. The same representation is shown to arise in other fields by the same type of ranked shuffling of distributions. We include the codon content of intergenic DNA sequences and the ranked distribution of sizes of trees in a determined area as examples. We show that the fittings proposed increase their accuracy with the number of distributions that are mixed and ranked.

  17. On a heuristic point of view concerning the citation distribution: introducing the Wakeby distribution.

    PubMed

    Katchanov, Yurij L; Markova, Yulia V

    2015-01-01

    The paper proposes a heuristic approach to modeling the cumulative distribution of citations of papers in scientific journals by means of the Wakeby distribution. The Markov process of citation leading to the Wakeby distribution is analyzed using the terminal time formalism. The Wakeby distribution is derived in the paper from the simple and general inhomogeneous Choquet-Deny convolution equation for a non-probability measure. We give statistical evidence that the Wakeby distribution is a reasonable approximation of the empirical citation distributions. AMS Subject Classification: 91D30; 91D99. PMID:25763305

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

    DOEpatents

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

    2014-11-11

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

  19. 47 CFR 54.515 - Distributing support.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Distributing support. 54.515 Section 54.515 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Schools and Libraries § 54.515 Distributing support. (a) A telecommunications carrier providing...

  20. 47 CFR 54.515 - Distributing support.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Distributing support. 54.515 Section 54.515 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Schools and Libraries § 54.515 Distributing support. (a) A telecommunications carrier providing...

  1. Distributed Leadership: According to the Evidence

    ERIC Educational Resources Information Center

    Harris, Alma

    2008-01-01

    Purpose: This paper aims to provide an overview of the literature concerning distributed leadership and organisational change. The main purpose of the paper is to consider the empirical evidence that highlights a relationship between distributed leadership and organisational outcomes. Design/methodological approach: The paper draws on several…

  2. 25 CFR 273.31 - Distribution formula.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Distribution formula. 273.31 Section 273.31 Indians... formula. (a) Funds shall be distributed to eligible contractors based upon the number of eligible Indian... formula. (b) The Assistant Secretary may make exceptions to the provisions of paragraph (a) of...

  3. Transversity distribution functions in the valon model

    NASA Astrophysics Data System (ADS)

    Alizadeh Yazdi, Z.; Taghavi-Shahri, F.; Arash, F.; Zomorrodian, M. E.

    2014-05-01

    We use the valon model to calculate the transversity distribution functions inside the nucleon. Transversity distributions indicate the probability to find partons with spin aligned (antialigned) to the transversely polarized nucleon. The results are in good agreement with all available experimental data and also global fits.

  4. Performance related issues in distributed database systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi

    1991-01-01

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

  5. 28 CFR 91.24 - Grant distribution.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Grant distribution. 91.24 Section 91.24 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) GRANTS FOR CORRECTIONAL FACILITIES Correctional Facilities on Tribal Lands § 91.24 Grant distribution. (a) From the amounts appropriated under section...

  6. Distributed cooperative control of AC microgrids

    NASA Astrophysics Data System (ADS)

    Bidram, Ali

    In this dissertation, the comprehensive secondary control of electric power microgrids is of concern. Microgrid technical challenges are mainly realized through the hierarchical control structure, including primary, secondary, and tertiary control levels. Primary control level is locally implemented at each distributed generator (DG), while the secondary and tertiary control levels are conventionally implemented through a centralized control structure. The centralized structure requires a central controller which increases the reliability concerns by posing the single point of failure. In this dissertation, the distributed control structure using the distributed cooperative control of multi-agent systems is exploited to increase the secondary control reliability. The secondary control objectives are microgrid voltage and frequency, and distributed generators (DGs) active and reactive powers. Fully distributed control protocols are implemented through distributed communication networks. In the distributed control structure, each DG only requires its own information and the information of its neighbors on the communication network. The distributed structure obviates the requirements for a central controller and complex communication network which, in turn, improves the system reliability. Since the DG dynamics are nonlinear and non-identical, input-output feedback linearization is used to transform the nonlinear dynamics of DGs to linear dynamics. Proposed control frameworks cover the control of microgrids containing inverter-based DGs. Typical microgrid test systems are used to verify the effectiveness of the proposed control protocols.

  7. 7 CFR 251.6 - Distribution plan.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 4 2013-01-01 2013-01-01 false Distribution plan. 251.6 Section 251.6 Agriculture... Distribution plan. (a) Contents of the plan. The State agency must submit for approval by the appropriate FNS Regional Office a plan which contains: (1) A designation of the State agency responsible for...

  8. 7 CFR 251.6 - Distribution plan.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Distribution plan. 251.6 Section 251.6 Agriculture... Distribution plan. (a) Contents of the plan. The State agency must submit for approval by the appropriate FNS Regional Office a plan which contains: (1) A designation of the State agency responsible for...

  9. 7 CFR 251.6 - Distribution plan.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 4 2012-01-01 2012-01-01 false Distribution plan. 251.6 Section 251.6 Agriculture... Distribution plan. (a) Contents of the plan. The State agency must submit for approval by the appropriate FNS Regional Office a plan which contains: (1) A designation of the State agency responsible for...

  10. 7 CFR 251.6 - Distribution plan.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Plan submission. A complete plan will be required for Fiscal Year 2001, to be submitted no later than... 7 Agriculture 4 2010-01-01 2010-01-01 false Distribution plan. 251.6 Section 251.6 Agriculture... Distribution plan. Link to an amendment published at 74 FR 62474, Nov. 30, 2009. (a) Contents of the plan....

  11. Distributing Radiant Heat in Insulation Tests

    NASA Technical Reports Server (NTRS)

    Freitag, H. J.; Reyes, A. R.; Ammerman, M. C.

    1986-01-01

    Thermally radiating blanket of stepped thickness distributes heat over insulation sample during thermal vacuum testing. Woven of silicon carbide fibers, blanket spreads heat from quartz lamps evenly over insulation sample. Because of fewer blanket layers toward periphery of sample, more heat initially penetrates there for more uniform heat distribution.

  12. Rawls and the Distribution of Education.

    ERIC Educational Resources Information Center

    Beattie, Catherine

    1982-01-01

    John Rawls has formulated two principles to capture our intuitions about justice and to guide us in efforts to realize it in society. Although he may consider the present distribution of resources for education just, a much more nearly equal distribution is both desirable and more consistent with Rawls' principles. (Author/BRR)

  13. Content Locality in Distributed Digital Libraries.

    ERIC Educational Resources Information Center

    Viles, Charles L.; French, James C.

    1999-01-01

    Introduces content locality--the degree to which content-similar documents are colocated in a distributed collection--in distributed digital libraries. Proposes two metrics for measurement of content locality, one based on topic signatures and the other based on collection statistics. Provides derivations and analysis of both metrics and uses them…

  14. 34 CFR 642.33 - Geographic distribution.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Geographic distribution. 642.33 Section 642.33 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY... Grant? § 642.33 Geographic distribution. The Secretary, to the greatest extent possible, awards...

  15. 28 CFR 91.24 - Grant distribution.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Grant distribution. 91.24 Section 91.24 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) GRANTS FOR CORRECTIONAL FACILITIES Correctional Facilities on Tribal Lands § 91.24 Grant distribution. (a) From the amounts appropriated under section...

  16. 5 CFR 1655.15 - Taxable distributions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... to be false; (5) With the exception of a loan described in 5 CFR 1620.45, the loan is not repaid in... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Taxable distributions. 1655.15 Section... Taxable distributions. (a) The Board may declare any unpaid loan principal, plus unpaid interest, to be...

  17. 5 CFR 1655.15 - Taxable distributions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... to be false; (5) With the exception of a loan described in 5 CFR 1620.45, the loan is not repaid in... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Taxable distributions. 1655.15 Section... Taxable distributions. (a) The Board may declare any unpaid loan principal, plus unpaid interest, to be...

  18. 28 CFR 91.24 - Grant distribution.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Grant distribution. 91.24 Section 91.24 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) GRANTS FOR CORRECTIONAL FACILITIES Correctional Facilities on Tribal Lands § 91.24 Grant distribution. (a) From the amounts appropriated under section...

  19. 7 CFR 3565.213 - Geographic distribution.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Geographic distribution. 3565.213 Section 3565.213 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.213 Geographic distribution....

  20. 7 CFR 3565.213 - Geographic distribution.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Geographic distribution. 3565.213 Section 3565.213 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.213 Geographic distribution....