WorldWideScience

Sample records for availability cluster system

  1. High availability cluster system using Linux-PC

    International Nuclear Information System (INIS)

    The KEK electron/positron linac provides its beams to four rings. As its operation time exceeds 7000 hours per year, recently, the stable operation is very important. The availability of the control system is essential. In order to achieve high availability, two kinds of cluster computer systems based on the Linux-PC technology was introduced and evaluated. (author)

  2. Towards the Availability of the Distributed Cluster Rendering System: Automatic Modeling and Verification

    DEFF Research Database (Denmark)

    Wang, Kemin; Jiang, Zhengtao; Wang, Yongbin;

    2012-01-01

    In this study, we proposed a Continuous Time Markov Chain Model towards the availability of n-node clusters of Distributed Rendering System. It's an infinite one, we formalized it, based on the model, we implemented a software, which can automatically model with PRISM language. With the tool, whe...

  3. High Availability Cluster System for Local Disaster Recovery with Markov Modeling Approach

    CERN Document Server

    Lwin, T T

    2009-01-01

    The need for high availability (HA) and disaster recovery (DR) in IT environment is more stringent than most of the other sectors of enterprises. Many businesses require the availability of business-critical applications 24 hours a day, seven days a week, and can afford no data loss in the event of a disaster. It is vital that the IT infrastructure is resilient with regard to disruption, even site failures, and that business operations can continue without significant impact. As a result, DR has gained great importance in IT. Clustering of multiple industries standard servers together to allow workload sharing and fail-over capabilities is a low cost approach. In this paper, we present the availability model through Semi-Markov Process (SMP) and also analyze the difference in downtime of the SMP model and the approximate Continuous Time Markov Chain (CTMC) model. To acquire system availability, we perform numerical analysis and SHARPE tool evaluation.

  4. Cluster-based DBMS Management Tool with High-Availability

    Directory of Open Access Journals (Sweden)

    Jae-Woo Chang

    2005-02-01

    Full Text Available A management tool which is needed for monitoring and managing cluster-based DBMSs has been little studied. So, we design and implement a cluster-based DBMS management tool with high-availability that monitors the status of nodes in a cluster system as well as the status of DBMS instances in a node. The tool enables users to recognize a single virtual system image and provides them with the status of all the nodes and resources in the system by using a graphic user interface (GUI. By using a load balancer, our management tool can increase the performance of a cluster-based DBMS as well as can overcome the limitation of the existing parallel DBMSs.

  5. 基于ServiceGuard构建医院高可用性集群系统%Construction of Cluster System with High Availability Based on ServiceGuard

    Institute of Scientific and Technical Information of China (English)

    钱硕

    2014-01-01

    目的:建立高可靠性和高效的双机集群系统,保障医院信息系统(HIS)的安全。方法根据医院新数据库服务器项目,基于HP Unix操作系统、MC/ServiceGuard集群基础架构构建双机集群系统。结果双机集群系统可提高HIS的安全性和抗灾能力,确保了医院业务的平稳流畅运行。结论使用ServiceGuard软件构建双机集群系统的方法易操作,值得推广。%Objective To construct a dual-computer cluster system with high reliability and efifciency to ensure the security of hospital information system.Methods The system was constructed with MC/Service Guard cluster infrastructure and HP Unix operating system according to the server items of the new databases in the hospital.Results The stable and smooth operation of hospital businesses has been ensured with the application of the system which runs well in the hospital.Conclusion The security and disaster tolerance have been improved with the application of the system.

  6. Simulation bounds for system availability

    International Nuclear Information System (INIS)

    System availability is a dominant factor in the practicality of nuclear power electrical generating plants. A proposed model for obtaining either lower bounds or interval estimates on availability uses observed data on ''n'' failure-to-repair cycles of the system to estimate the parameters in the time-to-failure and time-to-repair models. These estimates are then used in simulating failure/repair cycles of the system. The availability estimate is obtained for each of 5000 samples of ''n'' failure/repair cycles to form a distribution of estimates. Specific percentile points of those simulated distributions are selected as lower simulation bounds or simulation interval bounds for the system availability. The method is illustrated with operational data from two nuclear plants for which an exponential time-to-failure and a lognormal time-to-repair are assumed

  7. Availability of periodically tested systems

    International Nuclear Information System (INIS)

    There is at the present time a need in accurate models to asess the availability of periodically tested stand-by systems. This paper shows how to improve the well known 'saw-tooth curve' model in order to take into account various reliability parameters. A model is developed to assess the pointwise and the mean availabilities of periodically tested stand-by systems. Exact and approxination formulae are given. In addition, the model developed herein leads to optimize the test interval in order to minimize the mean unavailability. A safety diesel in a nuclear power plant is given as an example

  8. Supersymmetry for nuclear cluster systems

    International Nuclear Information System (INIS)

    A supersymmetry scheme is proposed for nuclear cluster systems. The bosonic sector of the superalgebra describes the relative motion of the clusters, while its fermionic sector is associated with their internal structure. An example of core+α configurations is discussed in which the core is a p-shell nucleus and the underlying superalgebra is U(4/12). The α-cluster states of the nuclei 20Ne and 19F are analysed and correlations between their spectra, electric quadrupole transitions, and one-nucleon transfer reactions are interpreted in terms of U(4/12) supersymmetry. (author)

  9. Active clusters in disordered systems

    International Nuclear Information System (INIS)

    We introduce an exact algorithm to calculate the distribution of large low energy clusters (droplets) in disordered manifolds and disordered magnets, and we analyze the extent to which these clusters can be treated as independent two-level systems. We show that interfaces in randomly diluted networks always have broad droplet distributions, while diluted antiferromagnets in a field can have either power law or exponential droplet distributions. copyright 1999 The American Physical Society

  10. Test System Impact on System Availability

    DEFF Research Database (Denmark)

    Pau, L. F.

    1987-01-01

    The specifications are presented for an imperfect automatic test system (ATS) (test frequency distribution, reliability, false alarm rate, nondetection rate) in order to account for the availability, readiness, mean time between unscheduled repairs (MTBUR), reliability, and maintenance of the...... system subject to monitoring and test. A time-dependent Markov model is presented, and applied in three cases, with examples of numerical results provided for preventive maintenance decisions, design of an automatic test system, buffer testing in computers, and data communications....

  11. Investigation of Cluster and Cluster Queuing System

    OpenAIRE

    Halifu, Saerda

    2008-01-01

    Cluster became main platform as parallel and distributed computing structure for high performance computing. Following the development of high performance computer architecture more and more different branches of natural science benefit fromhuge and efficient computational power. For instance bio-informatics, climate science, computational physics, computational chemistry, marine science, etc. Efficient and reliable computing powermay not only expending demand of existing high performance com...

  12. Elastic and Caloric Properties of Cluster Systems and Nanoparticles

    Directory of Open Access Journals (Sweden)

    G.A. Melnikov

    2014-07-01

    Full Text Available The mathematical relations to calculate the isobaric coefficient of thermal expansion, the coefficient of isobaric compressibility and difference of heats for cluster systems having got within the modified cluster model developed earlier by the authors on the assumption that in disordered condensed matters there is a cluster distribution by the particle number are conducted.

  13. Planetary systems in star clusters

    CERN Document Server

    Kouwenhoven, M B N; Cai, Maxwell Xu; Spurzem, Rainer

    2016-01-01

    Thousands of confirmed and candidate exoplanets have been identified in recent years. Consequently, theoretical research on the formation and dynamical evolution of planetary systems has seen a boost, and the processes of planet-planet scattering, secular evolution, and interaction between planets and gas/debris disks have been well-studied. Almost all of this work has focused on the formation and evolution of isolated planetary systems, and neglect the effect of external influences, such as the gravitational interaction with neighbouring stars. Most stars, however, form in clustered environments that either quickly disperse, or evolve into open clusters. Under these conditions, young planetary systems experience frequent close encounters with other stars, at least during the first 1-10 Myr, which affects planets orbiting at any period range, as well as their debris structures.

  14. Highly Available Trading System: Experiments with CORBA

    OpenAIRE

    Défago, X.; Mazouni, K. R.; Schiper, A.; Davies2, N; Raymond, K; Seitz, J.

    1998-01-01

    Highly Available Trading System: Experiments with CORBA X. Defago, K. R. Mazouni, and A. Schiper The Swiss Exchange system (SWX system) was the first stock exchange system in service to be fully computerised. For high availability, the trading system is built as a replicated service based on Isis. For portability reasons, the SWX team has considered basing the next version of the trading system on CORBA. Despite the numerous advantages of a CORBA based solution, it was necessary n...

  15. Availability Of JobTracker Machine In Hadoop/MapReduce Zookeeper Coordinated Clusters

    Directory of Open Access Journals (Sweden)

    Ekpe Okorafor

    2012-06-01

    Full Text Available It is difficult to use the traditional Message Passing Interface (MPI approach to implement synchronization, coordination, and prevent deadlocks in distributed systems. This difficulty is lessened by the use of Apache's Hadoop/MapReduce and Zookeeper to provide Fault Tolerance in a Homogeneously Distributed Hardware/Software environment. A mathematical model for the availability of the JobTracker in Hadoop/MapReduce using Zookeeper's Leader Election Service is presented in this paper. Although the availability is less than what is expected in f+1 Fault Tolerance systems for crash failures, this approach makes coordination and synchronization easy, reduces the effect of Byzantine faults and provides Fault Tolerance for distributed systems. The results obtained show that the availability changes with change in the number of Zookeeper servers. This model can help determine how many servers are optimal for high availability, from which vendor they must be purchased, and when to use a Zookeeper coordinated Hadoop cluster to perform safety critical tasks.

  16. Libra: An Economy driven Job Scheduling System for Clusters

    OpenAIRE

    Sherwani, Jahanzeb; Ali, Nosheen; Lotia, Nausheen; Hayat, Zahra; Buyya, Rajkumar

    2002-01-01

    Clusters of computers have emerged as mainstream parallel and distributed platforms for high-performance, high-throughput and high-availability computing. To enable effective resource management on clusters, numerous cluster managements systems and schedulers have been designed. However, their focus has essentially been on maximizing CPU performance, but not on improving the value of utility delivered to the user and quality of services. This paper presents a new computational economy driven ...

  17. Fossil systems in the 400d cluster catalog

    DEFF Research Database (Denmark)

    Voevodkin, Alexey; Borozdin, Konstantin; Heitmann, Katrin;

    2010-01-01

    We report the discovery of seven new fossil systems in the 400d cluster survey. Our search targets nearby, z ≤ 0.2, and X-ray bright, LX ≥ 10^43 erg s-1, clusters of galaxies. Where available, we measure the optical luminosities from Sloan Digital Sky Survey images, thereby obtaining uniform sets...

  18. System availability top-down apportionment method

    International Nuclear Information System (INIS)

    A top-down method for apportioning overall manufacturing facility availability among systems and subsystems is presented. Characteristics which influence equipment reliability are defined. Experts, using engineering judgement, score each characteristic for each equipment system whose availability design goal is to be established. Scores for each characteristic are combined into weighting factors. A mathematical model is derived which incorporates these weighting factors. This methodology establishes tradeoffs among facility systems: the method imposes high-availability requirements on those systems in which an incremental increase in availability is easier to attain, and lower requirements on those in which an increase in availability is more difficult and costly. An example application of the method is presented

  19. Dynamically allocated virtual clustering management system

    Science.gov (United States)

    Marcus, Kelvin; Cannata, Jess

    2013-05-01

    The U.S Army Research Laboratory (ARL) has built a "Wireless Emulation Lab" to support research in wireless mobile networks. In our current experimentation environment, our researchers need the capability to run clusters of heterogeneous nodes to model emulated wireless tactical networks where each node could contain a different operating system, application set, and physical hardware. To complicate matters, most experiments require the researcher to have root privileges. Our previous solution of using a single shared cluster of statically deployed virtual machines did not sufficiently separate each user's experiment due to undesirable network crosstalk, thus only one experiment could be run at a time. In addition, the cluster did not make efficient use of our servers and physical networks. To address these concerns, we created the Dynamically Allocated Virtual Clustering management system (DAVC). This system leverages existing open-source software to create private clusters of nodes that are either virtual or physical machines. These clusters can be utilized for software development, experimentation, and integration with existing hardware and software. The system uses the Grid Engine job scheduler to efficiently allocate virtual machines to idle systems and networks. The system deploys stateless nodes via network booting. The system uses 802.1Q Virtual LANs (VLANs) to prevent experimentation crosstalk and to allow for complex, private networks eliminating the need to map each virtual machine to a specific switch port. The system monitors the health of the clusters and the underlying physical servers and it maintains cluster usage statistics for historical trends. Users can start private clusters of heterogeneous nodes with root privileges for the duration of the experiment. Users also control when to shutdown their clusters.

  20. Globular Cluster Systems in Brightest Cluster Galaxies. II: NGC 6166

    CERN Document Server

    Harris, William E; Whitmore, Bradley C; Gnedin, Oleg Y; Geisler, Douglas; Rothberg, Barry

    2015-01-01

    We present new deep photometry of the globular cluster system (GCS) around NGC 6166, the central supergiant galaxy in Abell 2199. HST data from the ACS and WFC3 cameras in F475W, F814W are used to determine the spatial distribution of the GCS, its metallicity distribution function (MDF), and the dependence of the MDF on galactocentric radius and on GC luminosity. The MDF is extremely broad, with the classic red and blue subpopulations heavily overlapped, but a double-Gaussian model can still formally match the MDF closely. The spatial distribution follows a Sersic-like profile detectably to a projected radius of at least $R_{gc} = 250$ kpc. To that radius, the total number of clusters in the system is N_{GC} = 39000 +- 2000, the global specific frequency is S_N = 11.2 +- 0.6, and 57\\% of the total are blue, metal-poor clusters. The GCS may fade smoothly into the Intra-Cluster Medium of A2199; we see no clear transition from the core of the galaxy to the cD halo or the ICM. The radial distribution, projected e...

  1. Cluster formation in quantum critical systems

    International Nuclear Information System (INIS)

    The presence of magnetic clusters has been verified in both antiferromagnetic and ferromagnetic quantum critical systems. We review some of the strongest evidence for strongly doped quantum critical systems (Ce(Ru0.24Fe0.76)2Ge2) and we discuss the implications for the response of the system when cluster formation is combined with finite size effects. In particular, we discuss the change of universality class that is observed close to the order-disorder transition. We detail the conditions under which clustering effects will play a significant role also in the response of stoichiometric systems and their experimental signature.

  2. Classification of clusters in the system of information support of the clustering strategy

    Directory of Open Access Journals (Sweden)

    G.T. Piatnytska

    2015-12-01

    Full Text Available The aim of research is to develop recommendations to classify clusters within establishment and development of information system for clustering strategy implementation at the regional level, country level, etc. The main results of research. It is found that nowadays different semantic content and number of features to classify clusters are used in scientific sources and practice. Advantages and disadvantages of clusters depending on the purpose and basic conditions of their formation are identified. Different scientific approaches to typing of competitive clusters and clusters classification by development stages are compared. In June 2015, we interviewed 15 experts (businessmen, government officials, academics about the highest priority features of clusters classification in the data base required for the development and monitoring of the clustering strategy. It was determined that the highest priority features must be: sectoral affiliation; intensity of innovation policy within the cluster; divisions given its geographical component; export potential; number of employees and development stage (corresponding stages of the life cycle of cluster, which received respectively 1,5; 1,5; 3; 4,5; 4,5 and 6 standardized ranks among the twenty features of classification that are most often found in scientific publications and described in this study. Conclusions and directions of further researches. It is revealed that today the forming of clusters in Ukraine is still at an early stage, although the international practice of clustering has long confirmed of its positive impact on economic growth in the regions where it is implemented. One reason of this situation is inadequate information and advisory support of cluster policy in our country. It is recommended to establish national and regional information centers to provide information about: cluster initiative; active clusters and their members; international, national and regional programs to

  3. An Artificial Immune Classification and Clustering Systems: A Survey

    Directory of Open Access Journals (Sweden)

    Stephen Ajay Anurag Beri

    2014-01-01

    Full Text Available Artificial immune systems (AIS are a class of computationally intelligent systems which consider many properties of natural immune system .Several AIS are widely used in different application areas such as classification, clustering, web mining, virus detection, learning, image processing, robotics control, bio-informatics and anomaly detection. Among this classification and clustering are widely used areas. Most of the the artificial immune system used in the classification and clustering area make use some key features of AIS such as feature extraction, recognition and learning. This paper gives an effective survey aboutartificial immune systems which are used in the classification and clustering areasand also make use of the features such as feature selection, pattern recognition and machine learning.

  4. Risk based management of safety systems' availability

    International Nuclear Information System (INIS)

    The paper presents the results of Task 14 of the OECD/NEA Committee on the Safety of Nuclear Installations (CSNI) Principal Working Group 5. Following completion of work on 'PSA Application to Technical Specifications', Task 14 was initiated at the Autumn 1992 meeting of the Principal Working Group, and was completed at the end of 1994. The agreed objective of the task was to review the possibilities for using probabilistic safety analysis (PSA) based insights in the real time management of safety system reliability. The practicality of on-line risk based monitoring of safety systems' availability status has been demonstrated by seven years of experience at each of four nuclear power reactors in the United Kingdom. Within this experience many thousands of status changes have been monitored and evaluated. 4 refs, 3 figs

  5. Traffic Accident, System Model and Cluster Analysis in GIS

    Directory of Open Access Journals (Sweden)

    Veronika Vlčková

    2015-07-01

    Full Text Available One of the many often frequented topics as normal journalism, so the professional public, is the problem of traffic accidents. This article illustrates the orientation of considerations to a less known context of accidents, with the help of constructive systems theory and its methods, cluster analysis and geoinformation engineering. Traffic accident is reframing the space-time, and therefore it can be to study with tools of technology of geographic information systems. The application of system approach enabling the formulation of the system model, grabbed by tools of geoinformation engineering and multicriterial and cluster analysis.

  6. Clustering

    Directory of Open Access Journals (Sweden)

    Jinfei Liu

    2013-04-01

    Full Text Available DBSCAN is a well-known density-based clustering algorithm which offers advantages for finding clusters of arbitrary shapes compared to partitioning and hierarchical clustering methods. However, there are few papers studying the DBSCAN algorithm under the privacy preserving distributed data mining model, in which the data is distributed between two or more parties, and the parties cooperate to obtain the clustering results without revealing the data at the individual parties. In this paper, we address the problem of two-party privacy preserving DBSCAN clustering. We first propose two protocols for privacy preserving DBSCAN clustering over horizontally and vertically partitioned data respectively and then extend them to arbitrarily partitioned data. We also provide performance analysis and privacy proof of our solution..

  7. Clustering of periodic orbits in chaotic systems

    International Nuclear Information System (INIS)

    In the framework of the semiclassical approach, the universal spectral correlations in Hamiltonian systems with classical chaotic dynamics can be attributed to the systematic correlations between the actions of periodic orbits which (up to the switch in the momentum direction) pass through approximately the same points of the phase space. By considering symbolic dynamics of the system one can introduce a natural ultrametric distance between periodic orbits and organize them into clusters of orbits approaching each other in the phase space. We study the distribution of cluster sizes for the baker's map in the asymptotic limit of long trajectories. This problem is equivalent to the one of counting degeneracies in the length spectrum of the de Bruijn graphs. Based on this fact, we derive the probability Pk that k randomly chosen periodic orbits belong to the same cluster. Furthermore, we find asymptotic behaviour of the largest cluster size |Cmax| and derive the probability P(t) that a random periodic orbit belongs to a cluster smaller than t|Cmax|, t ∈ [0, 1]. (paper)

  8. Attitude Estimation in Fractionated Spacecraft Cluster Systems

    Science.gov (United States)

    Hadaegh, Fred Y.; Blackmore, James C.

    2011-01-01

    An attitude estimation was examined in fractioned free-flying spacecraft. Instead of a single, monolithic spacecraft, a fractionated free-flying spacecraft uses multiple spacecraft modules. These modules are connected only through wireless communication links and, potentially, wireless power links. The key advantage of this concept is the ability to respond to uncertainty. For example, if a single spacecraft module in the cluster fails, a new one can be launched at a lower cost and risk than would be incurred with onorbit servicing or replacement of the monolithic spacecraft. In order to create such a system, however, it is essential to know what the navigation capabilities of the fractionated system are as a function of the capabilities of the individual modules, and to have an algorithm that can perform estimation of the attitudes and relative positions of the modules with fractionated sensing capabilities. Looking specifically at fractionated attitude estimation with startrackers and optical relative attitude sensors, a set of mathematical tools has been developed that specify the set of sensors necessary to ensure that the attitude of the entire cluster ( cluster attitude ) can be observed. Also developed was a navigation filter that can estimate the cluster attitude if these conditions are satisfied. Each module in the cluster may have either a startracker, a relative attitude sensor, or both. An extended Kalman filter can be used to estimate the attitude of all modules. A range of estimation performances can be achieved depending on the sensors used and the topology of the sensing network.

  9. Q-systems as cluster algebras

    Energy Technology Data Exchange (ETDEWEB)

    Kedem, Rinat [Department of Mathematics, University of Illinois, 1409 West Green Street, Urbana, IL 61821 (United States)], E-mail: rinat@uiuc.edu

    2008-05-16

    Q-systems first appeared in the analysis of the Bethe equations for the XXX model and generalized Heisenberg spin chains (Kirillov and Reshetikhin 1987 Zap. Nauchn. Sem. Leningr. Otd. Mat. Inst. Steklov. 160 211-21, 301). Such systems are known to exist for any simple Lie algebra and many other Kac-Moody algebras. We formulate the Q-system associated with any simple, simply-laced Lie algebras g in the language of cluster algebras (Fomin and Zelevinsky 2002 J. Am. Math. Soc. 15 497-529), and discuss the relation of the polynomiality property of the solutions of the Q-system in the initial variables, which follows from the representation-theoretical interpretation, to the Laurent phenomenon in cluster algebras (Fomin and Zelevinsky 2002 Adv. Appl. Math. 28 119-44)

  10. HALR: A TCP Enhancement Scheme Using Local Caching in High-Availability Cluster

    Science.gov (United States)

    Feng, Yi-Hsuan; Huang, Nen-Fu; Wu, Yen-Min

    In this paper, we study the end-to-end TCP performance over a path deploying a High-Availability cluster, whose characteristics are highlighted by the failover procedure to remove single-point failure. This paper proposes an approach, called High-Availability Local Recovery (HALR), to enhance TCP performance in the face of a cluster failover. To minimize the latency of retransmission, HALR saves TCP packets selectively and resends them locally after the failover is finished. For better understanding, we further develop simple analytic models to predict the TCP performance in the aspect of flow latency under a range of failover times and the effects of HALR. Using simulation results, we validate our models and show that HALR improves the TCP performance significantly over a failover event as compared with the original TCP. Typically, HALR reduces the flow latency from 4.1sec to less than 1.9sec when the failover time equals to 500ms. The simulation by real packet trace further demonstrates that the memory requirement of the proposed solution is not a concern for modern network equipments.

  11. Traveling cluster approximation for uncorrelated amorphous systems

    International Nuclear Information System (INIS)

    In this paper, the authors apply the TCA concepts to spatially disordered, uncorrelated systems (e.g., fluids or amorphous metals without short-range order). This is the first approximation scheme for amorphous systems that takes cluster effects into account while preserving the Herglotz property for any amount of disorder. They have performed some computer calculations for the pair TCA, for the model case of delta-function potentials on a one-dimensional random chain. These results are compared with exact calculations (which, in principle, taken into account all cluster effects) and with the CPA, which is the single-site TCA. The density of states for the pair TCA clearly shows some improvement over the CPA, and yet, apparently, the pair approximation distorts some of the features of the exact results. They conclude that the effects of large clusters are much more important in an uncorrelated liquid metal than in a substitutional alloy. As a result, the pair TCA, which does quite a nice job for alloys, is not adequate for the liquid. Larger clusters must be treated exactly, and therefore an n-TCA with n > 2 must be used

  12. High available GNU/Linux systems

    OpenAIRE

    Rivero de la Cruz, Agustí

    2014-01-01

    High availability goals and ways to reach them, from a GNU/Linux point of view. Objetivos de alta disponibilidad y formas de llegar a ellos, desde el punto de vista de GNU/Linux. Objectius d'alta disponibilitat i formes d'arribar-hi, des del punt de vista de GNU/Linux.

  13. The HST/ACS Coma Cluster Survey IV. Intergalactic Globular Clusters and the Massive Globular Cluster System at the Core of the Coma Galaxy Cluster

    OpenAIRE

    Peng, Eric W.; Ferguson, Henry C.; Goudfrooij, Paul; Hammer, Derek; Lucey, John R.; Marzke, ; Ronald O.; Puzia, Thomas H.; Carter, David; Balcells, Marc; Bridges, Terry; Chiboucas, Kristin; del Burgo, Carlos; Graham, Alister W.; Guzman, Rafael; Hudson, Michael J.

    2011-01-01

    Intracluster stellar populations are a natural result of tidal interactions in galaxy clusters. Measuring these populations is difficult, but important for understanding the assembly of the most massive galaxies. The Coma cluster is one of the nearest truly massive galaxy clusters, and is host to a correspondingly large system of globular clusters (GCs). We use imaging from the HST/ACS Coma Cluster Survey to present the first definitive detection of a large population of intracluster GCs (IGC...

  14. Availability of a Renewable, Checked System

    DEFF Research Database (Denmark)

    Platz, O.

    1976-01-01

    Recurrent expressions are given for point and interval unavailability of a renewable system subjected to periodic checking/repair. The expressions are generalizations of the basic relations in the theory of discrete renewal processes. The asymptotic limits for long times follow simply from a...

  15. Clustering in correlated and uncorrelated percolative systems

    International Nuclear Information System (INIS)

    Clustering phenomena in two types of two-dimensional systems exhibiting correlated precolation are studied by Monte Carlo techniques. One of these is an Ising spin glass in which the curved plaquettes (i.e. elementary cells having odd number of frustrated bonds) are treated as ''particles''. The other system is a lattice gas model in which the occupation of a given site depends on the occupation probabilities of its nearest-neighbouring sites as well as on the temperature of the lattice. The peak in the weighted average cluster size in both of these systems is shifted towards lower concentration as compared with the corresponding case of uncorrelated percolation, indicating an earlier on-set of percolation threshold. The peaks in the total number of clusters as a function of density, however, is shifted towards higher concentrations in the Ising spin glass and towards lower concentrations in the kinetic Ising model. The results for the corresponding uncorrelated percolation systems are obtained with the help of the low density series expansion of Sykes and Glen. (author)

  16. Early evolution of the birth cluster of the solar system

    OpenAIRE

    Pfalzner, Susanne

    2012-01-01

    The solar system was most likely born in a star cluster containing at least 1000 stars. It is highly probable that this cluster environment influenced various properties of the solar system like its chemical composition, size and the orbital parameters of some of its constituting bodies. In the Milky Way, clusters with more than 2000 stars only form in two types - starburst clusters and leaky clusters - each following a unique temporal development in the mass-radius plane. The aim is here to ...

  17. Dynamic Resource Management in a Cluster for Scalability and High-Availability

    OpenAIRE

    Gallard, Pascal; Morin, Christine; Lottiaux, Renaud

    2002-01-01

    In order to execute high performance applications on a cluster, it is highly desirable to provide distributed services that globally manage physical resources distributed over the cluster nodes. However, as a distributed service may use resources located on different nodes, it becomes sensitive to changes in the cluster configuration due to node addition, reboot or failure. In this paper, we propose a generic service performing dynamic resource management in a cluster in order to provide dist...

  18. Rotary Mode Core Sample System availability improvement

    International Nuclear Information System (INIS)

    The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2

  19. Application of Cluster Analysis In Expert System - A Brief Survey

    Directory of Open Access Journals (Sweden)

    Mamta Tiwari

    2011-09-01

    Full Text Available This is era of knowledge and information. One very major task that has been evolved now a day is to mine a knowledge base. On the other hand expert systems are used extensively in many domains. There are many applications of expert systems for predicting and finding a feasible solution for any particular problem. Various tools also have been evolves for upgrading and modifying the existing expert systems and making them more useful in their intended purposes. The current paper explains the expert systems that use cluster analysis as a tool and briefly discusses few such expert systems.

  20. Clustering phenomena in superheavy nuclear systems

    International Nuclear Information System (INIS)

    Dynamics of heavy-ion low energy damped collisions is studied within the model based on the Langevin type equations. Shell effects on the multi-dimensional potential energy surface play an important role in these reactions. This leads to several local minima on the fission path of heavy nucleus — so called isomeric states which are nothing else but the two-cluster configurations with magic or semi-magic cores surrounded with a certain number of shared nucleons. In a giant nuclear system (formed, for example, in U + U collision) the three-body clustering configurations may also appear. Enhanced yield of the nuclides far from the projectile and target masses was found in the multi-nucleon transfer reactions due to the shell effects. It suggests that the low-energy damped collisions of transactinide nuclei may be used as an alternative way for the production of surviving superheavy long-living neutron-rich nuclei. (author)

  1. Using an MPI Cluster in the Control of a Mobile Robots System

    Directory of Open Access Journals (Sweden)

    Mohamed Salim LMIMOUNI

    2014-07-01

    Full Text Available Recently, HPC (High Performance Computing systems have gone from supercomputers to clusters. The clusters are used in all tasks that require very high computing power such as weather forecasting, climate research, molecular modeling, physical simulations, cryptanalysis, etc. The use of clusters is increasingly important in the scientific community, where the need for high performance computing (HPC is still growing. In this paper, we propose an improvement of a mobile robots system control by using an MPI (Message Passing Interface cluster. This cluster will launch, manipulate and process data from multiple robots simultaneously.

  2. Comparing current cluster, massively parallel, and accelerated systems

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Kevin J [Los Alamos National Laboratory; Davis, Kei [Los Alamos National Laboratory; Hoisie, Adolfy [Los Alamos National Laboratory; Kerbyson, Darren J [Los Alamos National Laboratory; Pakin, Scott [Los Alamos National Laboratory; Lang, Mike [Los Alamos National Laboratory; Sancho Pitarch, Jose C [Los Alamos National Laboratory

    2010-01-01

    Currently there is large architectural diversity in high perfonnance computing systems. They include 'commodity' cluster systems that optimize per-node performance for small jobs, massively parallel processors (MPPs) that optimize aggregate perfonnance for large jobs, and accelerated systems that optimize both per-node and aggregate performance but only for applications custom-designed to take advantage of such systems. Because of these dissimilarities, meaningful comparisons of achievable performance are not straightforward. In this work we utilize a methodology that combines both empirical analysis and performance modeling to compare clusters (represented by a 4,352-core IB cluster), MPPs (represented by a 147,456-core BG/P), and accelerated systems (represented by the 129,600-core Roadrunner) across a workload of four applications. Strengths of our approach include the ability to compare architectures - as opposed to specific implementations of an architecture - attribute each application's performance bottlenecks to characteristics unique to each system, and to explore performance scenarios in advance of their availability for measurement. Our analysis illustrates that application performance is essentially unrelated to relative peak performance but that application performance can be both predicted and explained using modeling.

  3. Dynamical evolution of globular-cluster systems in clusters of galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Muzzio, J.C.

    1987-04-01

    The dynamical processes that affect globular-cluster systems in clusters of galaxies are analyzed. Two-body and impulsive approximations are utilized to study dynamical friction, drag force, tidal stripping, tidal radii, globular-cluster swapping, tidal accretion, and galactic cannibalism. The evolution of galaxies and the collision of galaxies are simulated numerically; the steps involved in the simulation are described. The simulated data are compared with observations. Consideration is given to the number of galaxies, halo extension, location of the galaxies, distribution of the missing mass, nonequilibrium initial conditions, mass dependence, massive central galaxies, globular-cluster distribution, and lost globular clusters. 116 references.

  4. SYSTEMS OF PARTICLES WITH INTERACTION AND THE CLUSTER FORMATION IN CONDENSED MATTER

    Directory of Open Access Journals (Sweden)

    V.Krasnoholovets

    2003-01-01

    Full Text Available We investigate the behaviour of a system of particles with the different character of interaction. The approach makes it possible to describe systems of interacting particles by statistical methods taking into account a spatial nonhomogeneous distribution of particles, i.e. cluster formation. For these clusters are evaluated: their size, the number of particles in a cluster, and the temperature of phase transition to the cluster state. Three systems are under consideration: electrons on the liquid helium surface, particles interacting by the shielding Coulomb potential, which are found under the effect of an elastic field (e.g. nucleons in a nucleus, and gravitating masses with the Hubble expansion.

  5. SEQOPTICS: a protein sequence clustering system

    OpenAIRE

    2006-01-01

    Background Protein sequence clustering has been widely used as a part of the analysis of protein structure and function. In most cases single linkage or graph-based clustering algorithms have been applied. OPTICS (Ordering Points To Identify the Clustering Structure) is an attractive approach due to its emphasis on visualization of results and support for interactive work, e.g., in choosing parameters. However, OPTICS has not been used, as far as we know, for protein sequence clustering. Resu...

  6. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability

  7. Research on High-Availability of Softswitch System

    Institute of Scientific and Technical Information of China (English)

    LOU Zhi-qiang; LIAO Ning

    2006-01-01

    Since softswitch is the kernel of the Next Generation Network (NGN), it is practically significant to improve the availability of the softswitch system. This paper expatiates upon the methods of realizing the high-availability of softswitch system. It gives the methods from a multi-level viewpoint: software-level high-availability design, platformlevel high-availability of softswitch kernel components, network-level high-availability. Additonally, it gives certain analysis on obtaining network high-availability.

  8. A comparison of queueing, cluster and distributed computing systems

    Science.gov (United States)

    Kaplan, Joseph A.; Nelson, Michael L.

    1993-01-01

    Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in their design philosophy and implementation. Based on published reports on the different systems and conversations with the system's developers and vendors, a comparison of the systems are made on the integral issues of clustered computing.

  9. Continuous spectrum of three-cluster systems

    International Nuclear Information System (INIS)

    For the example of the 5H = 3H + n + n nucleus, the effect of the Pauli exclusion principle on the asymptotic behavior of wave functions for the continuous spectrum of three-cluster systems is studied within a microscopic approach. It is shown that, in the asymptotic limit, the Schrödinger equation for the wave function that describes the relative motion of tritium and two neutrons reduces to the multichannel problem of valence-neutron scattering on the 4H subsystem. The single-channel approximation within which the phase shift for neutron scattering on the 4H subsystem occurring in the lowest energy state is the only feature that characterizes the continuous spectrum of the 5H nucleus is proposed and implemented.

  10. On the Timing Analysis of Cluster based Communication Devices for Large Scale Computing Systems

    OpenAIRE

    Mohammed Mahfooz Sheikh; Khan, A.M.; U.N.Sinha

    2012-01-01

    Many parallel computing environments utilize cluster based architecture for large scale computing owing to the ease of their availability. As the cluster based approach may be used extensively,the interconnection mechanism plays a vital role in the performance of the system. The globally coupled class of problem is generally not amenable with the cluster based approach due to its substantial demand for communication across the architecture. In this paper we present a timing analysis of standa...

  11. Cluster dynamics and cluster size distributions in systems of self-propelled particles

    CERN Document Server

    Peruani, Fernando; Baer, Markus

    2014-01-01

    Systems of self-propelled particles (SPP) interacting by a velocity alignment mechanism in the presence of noise exhibit a rich clustering dynamics. It can be argued that clusters are responsible for the distribution of (local) information in these systems. Here, we investigate the statistical properties of single clusters in SPP systems, like the asymmetric spreading of clusters with respect to their moving direction. In addition, we formulate a Smoluchowski-type kinetic model to describe the evolution of the cluster size distribution (CSD). This model predicts the emergence of steady-state CSDs in SPP systems. We test our theoretical predictions in simulations of SPP with nematic interactions and find that our simple kinetic model reproduces qualitatively the transition to aggregation observed in simulations.

  12. Methodology for the systems engineering process. Volume 3: Operational availability

    Science.gov (United States)

    Nelson, J. H.

    1972-01-01

    A detailed description and explanation of the operational availability parameter is presented. The fundamental mathematical basis for operational availability is developed, and its relationship to a system's overall performance effectiveness is illustrated within the context of identifying specific availability requirements. Thus, in attempting to provide a general methodology for treating both hypothetical and existing availability requirements, the concept of an availability state, in conjunction with the more conventional probability-time capability, is investigated. In this respect, emphasis is focused upon a balanced analytical and pragmatic treatment of operational availability within the system design process. For example, several applications of operational availability to typical aerospace systems are presented, encompassing the techniques of Monte Carlo simulation, system performance availability trade-off studies, analytical modeling of specific scenarios, as well as the determination of launch-on-time probabilities. Finally, an extensive bibliography is provided to indicate further levels of depth and detail of the operational availability parameter.

  13. On cluster systems of tensor product systems of Hilbert spaces

    OpenAIRE

    Mukherjee, Mithun

    2015-01-01

    It is known that the spatial product of two product systems is intrinsic. Here we extend this result by analyzing subsystems of the tensor product of product systems. A relation with cluster systems is established. In a special case, we show that the amalgamated product of product systems through strictly contractive units is independent of the choices of the units. The amalgamated product in this case is isomorphic to the tensor product of the spatial product of the two and the type I produc...

  14. BOUNDED MINIMUM INHERENT AVAILABILITY REQUIREMENTS FOR THE SYSTEM DESCRIPTION DOCUMENTS

    International Nuclear Information System (INIS)

    The purpose of this analysis is to establish bounded minimum inherent availability requirements for the Mined Geologic Disposal System (MGDS) System Description Documents (SDDs). The purpose of the bounded minimum inherent availability is to provide a lower bound on availability which will allow design to meet throughput requirements while not affecting the ability of the items to perform their intended safety function

  15. Recommending the heterogeneous cluster type multi-processor system computing

    International Nuclear Information System (INIS)

    Real-time reactor simulator had been developed by reusing the equipment of the Musashi reactor and its performance improvement became indispensable for research tools to increase sampling rate with introduction of arithmetic units using multi-Digital Signal Processor(DSP) system (cluster). In order to realize the heterogeneous cluster type multi-processor system computing, combination of two kinds of Control Processor (CP) s, Cluster Control Processor (CCP) and System Control Processor (SCP), were proposed with Large System Control Processor (LSCP) for hierarchical cluster if needed. Faster computing performance of this system was well evaluated by simulation results for simultaneous execution of plural jobs and also pipeline processing between clusters, which showed the system led to effective use of existing system and enhancement of the cost performance. (T. Tanaka)

  16. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

  17. Transitions at CpG dinucleotides, geographic clustering of TP53 mutations and food availability patterns in colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Fabio Verginelli

    Full Text Available BACKGROUND: Colorectal cancer is mainly attributed to diet, but the role exerted by foods remains unclear because involved factors are extremely complex. Geography substantially impacts on foods. Correlations between international variation in colorectal cancer-associated mutation patterns and food availabilities could highlight the influence of foods on colorectal mutagenesis. METHODOLOGY: To test such hypothesis, we applied techniques based on hierarchical clustering, feature extraction and selection, and statistical pattern recognition to the analysis of 2,572 colorectal cancer-associated TP53 mutations from 12 countries/geographic areas. For food availabilities, we relied on data extracted from the Food Balance Sheets of the Food and Agriculture Organization of the United Nations. Dendrograms for mutation sites, mutation types and food patterns were constructed through Ward's hierarchical clustering algorithm and their stability was assessed evaluating silhouette values. Feature selection used entropy-based measures for similarity between clusterings, combined with principal component analysis by exhaustive and heuristic approaches. CONCLUSION/SIGNIFICANCE: Mutations clustered in two major geographic groups, one including only Western countries, the other Asia and parts of Europe. This was determined by variation in the frequency of transitions at CpGs, the most common mutation type. Higher frequencies of transitions at CpGs in the cluster that included only Western countries mainly reflected higher frequencies of mutations at CpG codons 175, 248 and 273, the three major TP53 hotspots. Pearson's correlation scores, computed between the principal components of the datamatrices for mutation types, food availability and mutation sites, demonstrated statistically significant correlations between transitions at CpGs and both mutation sites and availabilities of meat, milk, sweeteners and animal fats, the energy-dense foods at the basis of

  18. FarMon: an extensible, efficient cluster monitoring system

    International Nuclear Information System (INIS)

    The authors present the design and implementation of FarMon- a flexible event monitoring system for computing cluster. Using several techniques including DCL (Dynamic Class Loading) technique, module publish/subscribe/unsubscribe protocol and directory service, the authors create a high efficient, high extensible and high portable cluster monitoring system

  19. Cluster Computing for Embedded/Real-Time Systems

    Science.gov (United States)

    Katz, D.; Kepner, J.

    1999-01-01

    Embedded and real-time systems, like other computing systems, seek to maximize computing power for a given price, and thus can significantly benefit from the advancing capabilities of cluster computing.

  20. Quark cluster model in the three-nucleon system

    International Nuclear Information System (INIS)

    The quark cluster model is used to investigate the structure of the three-nucleon systems. The nucleon-nucleon interaction is proposed considering the colour-nucleon clusters and incorporating the quark degrees of freedom. The quark-quark potential in the quark compound bag model agrees with the central force potentials. The confinement potential reduces the short-range repulsion. The colour van der Waals force is determined. Then, the probability of quark clusters in the three-nucleon bound state systems are numerically calculated using realistic nuclear wave functions. The results of the present calculations show that quarks cluster themselves in three-quark systems building the quark cluster model for the trinucleon system. (author)

  1. Availability Of A Complex System Using MATLAB amp Comparison

    OpenAIRE

    Upasana; Dr. Neetu Gupta; Dr Yogesh Kumar Goyal

    2015-01-01

    Abstact In this paper MATLAB has been applied on differential difference equation to obtain availability MTTF etc. of a complex system. Though availability can also be found by other methods like matrix method 2 Laplace transformation method 7 etc. but with the help of MATLAB it is easy to find availability compared to other methods. Zaidi Zeenat et. al. 3 applied the method of MATLAB to a simple system. We in this paper applied the MATLAB to a two element standby system having perfect switc...

  2. From geographical innovation clusters towards virtual innovation clusters: The innovation virtual system

    OpenAIRE

    Passiante, Giuseppina; Secundo, Giustina

    2002-01-01

    The opportunities of the new economic landscape have determined radical changes in the organizational structures of the firms, till the creation of new virtual clusterization forms, that is distinct systems of suppliers, distributors, service providers and clients that use the 'internetworking technologies' as a principal way for co-operating and competing. These 'virtual clusterization forms' that have been also defined as 'e-business communities' or 'b-web communities' (Tapscott, Lowy & Tic...

  3. Interconnection of Clusters of Various Architectures in Grid Systems

    Directory of Open Access Journals (Sweden)

    Ovidiu GHERMAN

    2012-01-01

    Full Text Available The future of computing seems to be parallel. The computers built with general purpose processors are superseded nowadays by systems built around processors with multiple cores that are designed to operate with massive amount of arithmetic operation. And more frequently these processors are able to implement an internal parallelism. A similar step was made by IBM when they proposed that a unit dedicated to arithmetical operations to be used as an accelerator node for a cluster controlled by nodes with general purpose architecture. A new approach has been made towards high performance computing (HPC, in the form of hybrid architectures. However, using machines with different architecture as a single system can pose problems in application deployment. The paper analyse these difficulties and proposes a procedure to implement a multi-level parallelism at the application level. The experimental results are discussed

  4. Reliability, Availability, and Maintainability of Intermittently-usedRepairable Systems

    Directory of Open Access Journals (Sweden)

    P.S. Rajpal

    2007-03-01

    Full Text Available A composite measure comprising linear combination of reliability, availability, andmaintainability (CMRAM is proposed for an intermittently-used complex repairable system,namely a transport helicopter. The failure data are fitted in Weibull distribution for overlappingintervals of operating time to capture the effect of recent maintenance and other actions. Evaluationof CMRAM is helpful in formulating future operational and maintenance strategies.

  5. Simulation methods for reliability and availability of complex systems

    CERN Document Server

    Faulin Fajardo, Javier; Martorell Alsina, Sebastián Salvador; Ramirez-Marquez, Jose Emmanuel; Martorell, Sebastian

    2010-01-01

    This text discusses the use of computer simulation-based techniques and algorithms to determine reliability and/or availability levels in complex systems and to help improve these levels both at the design stage and during the system operating stage.

  6. RELIABILITY ANALYSIS OF RING, AGENT AND CLUSTER BASED DISTRIBUTED SYSTEMS

    Directory of Open Access Journals (Sweden)

    R.SEETHALAKSHMI

    2011-08-01

    Full Text Available The introduction of pervasive devices and mobile devices has led to immense growth of real time distributed processing. In such context reliability of the computing environment is very important. Reliability is the probability that the devices, links, processes, programs and files work efficiently for the specified period of time and in the specified condition. Distributed systems are available as conventional ring networks, clusters and agent based systems. Reliability of such systems is focused. These networks are heterogeneous and scalable in nature. There are several factors, which are to be considered for reliability estimation. These include the application related factors like algorithms, data-set sizes, memory usage pattern, input-output, communication patterns, task granularity and load-balancing. It also includes the hardware related factors like processor architecture, memory hierarchy, input-output configuration and network. The software related factors concerning reliability are operating systems, compiler, communication protocols, libraries and preprocessor performance. In estimating the reliability of a system, the performance estimation is an important aspect. Reliability analysis is approached using probability.

  7. Availability, reliability and downtime of systems with repairable components

    International Nuclear Information System (INIS)

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and lower bound reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in time and repair durations are assumed to be exponentially distributed. The results are expressed in terms of the mean rates of failure and mean durations of repair of the individual components. Closed-form expressions are also derived for the rates of change of the various probabilistic system performance measures with respect to the mean rate of failure and the mean duration of repair of each component. These expressions provide a convenient framework for identifying important components within the system and for decision-making aimed at upgrading the system availability or reliability, or reducing the mean duration of system downtime. Example applications to an electrical substation system demonstrate the use of the formulas developed in the paper

  8. Space Transportation System Availability Requirements and Its Influencing Attributes Relationships

    Science.gov (United States)

    Rhodes, Russel E.; Adams, TImothy C.

    2008-01-01

    It is essential that management and engineering understand the need for an availability requirement for the customer's space transportation system as it enables the meeting of his needs, goal, and objectives. There are three types of availability, e.g., operational availability, achieved availability, or inherent availability. The basic definition of availability is equal to the mean uptime divided by the sum of the mean uptime plus the mean downtime. The major difference is the inclusiveness of the functions within the mean downtime and the mean uptime. This paper will address tIe inherent availability which only addresses the mean downtime as that mean time to repair or the time to determine the failed article, remove it, install a replacement article and verify the functionality of the repaired system. The definitions of operational availability include the replacement hardware supply or maintenance delays and other non-design factors in the mean downtime. Also with inherent availability the mean uptime will only consider the mean time between failures (other availability definitions consider this as mean time between maintenance - preventive and corrective maintenance) that requires the repair of the system to be functional. It is also essential that management and engineering understand all influencing attributes relationships to each other and to the resultant inherent availability requirement. This visibility will provide the decision makers with the understanding necessary to place constraints on the design definition for the major drivers that will determine the inherent availability, safety, reliability, maintainability, and the life cycle cost of the fielded system provided the customer. This inherent availability requirement may be driven by the need to use a multiple launch approach to placing humans on the moon or the desire to control the number of spare parts required to support long stays in either orbit or on the surface of the moon or mars. It is

  9. Structural factors of solar system cluster ground coupled storage rationalization

    OpenAIRE

    Viktor V. Wysochin; Аnna S. Golovatyuk

    2015-01-01

    The computational investigations of unsteady heat transfer in seasonal solar heat storage system were conducted. This storage system consists of nine ground heat exchangers. The investigations were made for periodical diurnal cycle charging during summer season. The heat exchanger is presented as vertical probe with concentric tubes arrangement. Aim: The aim of the work is the optimization of cluster ground coupled storage – the probes quantity in cluster, their lengths and interval – using h...

  10. A High-Availability, Distributed Hardware Control System Using Java

    Science.gov (United States)

    Niessner, Albert F.

    2011-01-01

    Two independent coronagraph experiments that require 24/7 availability with different optical layouts and different motion control requirements are commanded and controlled with the same Java software system executing on many geographically scattered computer systems interconnected via TCP/IP. High availability of a distributed system requires that the computers have a robust communication messaging system making the mix of TCP/IP (a robust transport), and XML (a robust message) a natural choice. XML also adds the configuration flexibility. Java then adds object-oriented paradigms, exception handling, heavily tested libraries, and many third party tools for implementation robustness. The result is a software system that provides users 24/7 access to two diverse experiments with XML files defining the differences

  11. Reliability and availability requirements analysis for DEMO: fuel cycle system

    International Nuclear Information System (INIS)

    The Demonstration Power Plant (DEMO) will be a fusion reactor prototype designed to demonstrate the capability to produce electrical power in a commercially acceptable way. Two of the key elements of the engineering development of the DEMO reactor are the definitions of reliability and availability requirements (or targets). The availability target for a hypothesized Fuel Cycle has been analysed as a test case. The analysis has been done on the basis of the experience gained in operating existing tokamak fusion reactors and developing the ITER design. Plant Breakdown Structure (PBS) and Functional Breakdown Structure (FBS) related to the DEMO Fuel Cycle and correlations between PBS and FBS have been identified. At first, a set of availability targets has been allocated to the various systems on the basis of their operating, protection and safety functions. 75% and 85% of availability has been allocated to the operating functions of fuelling system and tritium plant respectively. 99% of availability has been allocated to the overall systems in executing their safety functions. The chances of the systems to achieve the allocated targets have then been investigated through a Failure Mode and Effect Analysis and Reliability Block Diagram analysis. The following results have been obtained: 1) the target of 75% for the operations of the fuelling system looks reasonable, while the target of 85% for the operations of the whole tritium plant should be reduced to 80%, even though all the tritium plant systems can individually reach quite high availability targets, over 90% - 95%; 2) all the DEMO Fuel Cycle systems can reach the target of 99% in accomplishing their safety functions. (authors)

  12. Identifying phase synchronization clusters in spatially extended dynamical systems

    CERN Document Server

    Bialonski, Stephan; 10.1103/PhysRevE.74.051909

    2010-01-01

    We investigate two recently proposed multivariate time series analysis techniques that aim at detecting phase synchronization clusters in spatially extended, nonstationary systems with regard to field applications. The starting point of both techniques is a matrix whose entries are the mean phase coherence values measured between pairs of time series. The first method is a mean field approach which allows to define the strength of participation of a subsystem in a single synchronization cluster. The second method is based on an eigenvalue decomposition from which a participation index is derived that characterizes the degree of involvement of a subsystem within multiple synchronization clusters. Simulating multiple clusters within a lattice of coupled Lorenz oscillators we explore the limitations and pitfalls of both methods and demonstrate (a) that the mean field approach is relatively robust even in configurations where the single cluster assumption is not entirely fulfilled, and (b) that the eigenvalue dec...

  13. An Ontology-based Knowledge Management System for Industry Clusters

    CERN Document Server

    Sureephong, Pradorn; Ouzrout, Yacine; Bouras, Abdelaziz

    2008-01-01

    Knowledge-based economy forces companies in the nation to group together as a cluster in order to maintain their competitiveness in the world market. The cluster development relies on two key success factors which are knowledge sharing and collaboration between the actors in the cluster. Thus, our study tries to propose knowledge management system to support knowledge management activities within the cluster. To achieve the objectives of this study, ontology takes a very important role in knowledge management process in various ways; such as building reusable and faster knowledge-bases, better way for representing the knowledge explicitly. However, creating and representing ontology create difficulties to organization due to the ambiguity and unstructured of source of knowledge. Therefore, the objectives of this paper are to propose the methodology to create and represent ontology for the organization development by using knowledge engineering approach. The handicraft cluster in Thailand is used as a case stu...

  14. Mission Availability for Bounded-Cumulative-Downtime System

    Science.gov (United States)

    Zhou, Yu; Kou, Gang; Ergu, Daji; Peng, Yi

    2013-01-01

    In this research, a mathematics model is proposed to describe the mission availability for bounded-cumulative-downtime system. In the proposed model, the cumulative downtime and cumulative uptime are considered as constraints simultaneously. The mission availability can be defined as the probability that all repairs do not exceed the bounded cumulative downtime constraint of such system before the cumulative uptime has accrued. There are two mutually exclusive cases associated with the probability. One case is the system has not failed, where the probability can be described by system reliability. The other case is the system has failed and the cumulative downtime does not exceed the constraint before the cumulative uptime has accrued. The mathematic description of the probability under the second case is very complex. And the cumulative downtime in a mission can be set as a random variable, whose cumulative distribution means the probability that the failure system can be restored to the operating state. Giving the dependence in the scheduled mission, a mission availability model with closed form expression under this assumption is proposed. Numerical simulations are presented to illustrate the effectiveness of the proposed model. The results indicate that the relative errors are acceptable and the proposed model is effective. Furthermore, three important applications of the proposed mission availability model are discussed. PMID:23843940

  15. Space Transportation System Availability Relationships to Life Cycle Cost

    Science.gov (United States)

    Rhodes, Russel E.; Donahue, Benjamin B.; Chen, Timothy T.

    2009-01-01

    Future space transportation architectures and designs must be affordable. Consequently, their Life Cycle Cost (LCC) must be controlled. For the LCC to be controlled, it is necessary to identify all the requirements and elements of the architecture at the beginning of the concept phase. Controlling LCC requires the establishment of the major operational cost drivers. Two of these major cost drivers are reliability and maintainability, in other words, the system's availability (responsiveness). Potential reasons that may drive the inherent availability requirement are the need to control the number of unique parts and the spare parts required to support the transportation system's operation. For more typical space transportation systems used to place satellites in space, the productivity of the system will drive the launch cost. This system productivity is the resultant output of the system availability. Availability is equal to the mean uptime divided by the sum of the mean uptime plus the mean downtime. Since many operational factors cannot be projected early in the definition phase, the focus will be on inherent availability which is equal to the mean time between a failure (MTBF) divided by the MTBF plus the mean time to repair (MTTR) the system. The MTBF is a function of reliability or the expected frequency of failures. When the system experiences failures the result is added operational flow time, parts consumption, and increased labor with an impact to responsiveness resulting in increased LCC. The other function of availability is the MTTR, or maintainability. In other words, how accessible is the failed hardware that requires replacement and what operational functions are required before and after change-out to make the system operable. This paper will describe how the MTTR can be equated to additional labor, additional operational flow time, and additional structural access capability, all of which drive up the LCC. A methodology will be presented that

  16. High availability based on production information systems research and practice

    International Nuclear Information System (INIS)

    Through the presentation of the production information system application deployment in Qinshan Nuclear Power Co., Ltd., combined with CEAS failure to deal with, respectively, in the server (operating system), database and application software on-going monitoring and tuning of the actual cases are discussed: For the system to maintain a high availability, performance and security, not only on the server (operating system) for rational allocation and deployment, but also the need for database and application software to optimize the well-designed and sustained. (authors)

  17. Improving availability and reliability of high accuracy integrated systems

    Energy Technology Data Exchange (ETDEWEB)

    Altmayer, C. [Technical Univ. Braunschweig (Germany). Inst. of Flight Guidance and Control

    2000-07-01

    Satellite navigation systems are widely used for high accuracy applications like automated vehicle guidance demanding the usage of the most accurate ranging information obtainable from satellite navigation systems, the carrier phase observables. These observables can be affected by cycle slips due to high dynamic or short signal blocking. A detection and correction scheme was developed using an integrated system consisting of an inertial measurement unit (IMU) and a differential GPS (global positioning system) sensor. With this method the availability and reliability of cycle slip free carrier phase information is greatly enhanced. (orig.)

  18. Clusters and cluster initiatives: The role of collaboration and social capital in building a system of innovation in Ireland.

    OpenAIRE

    Ivory, Patrick R.

    2012-01-01

    In Ireland, interest in the cluster concept (Porter 1990. 2003) dates back to the 1990s when enterprise policy focused on the development of competitive advantage in clusters of interlinked sectors (Doyle and Fanning 2007, Culliton 1992). Research in the early 1990s, found a weak system of innovation in Ireland and advocated a focus on broad institutional factors and the potential of clusters in the development of a national system of innovation (Mjøset 1992). International cluster policy is ...

  19. NATO Advanced Research Workshop on Physics and Chemistry of Finite Systems : from Clusters to Crystals

    CERN Document Server

    Khanna, S; Rao, B

    1992-01-01

    Recent innovations in experimental techniques such as molecular and cluster beam epitaxy, supersonic jet expansion, matrix isolation and chemical synthesis are increasingly enabling researchers to produce materials by design and with atomic dimension. These materials constrained by sire, shape, and symmetry range from clusters containing as few as two atoms to nanoscale materials consisting of thousands of atoms. They possess unique structuraI, electronic, magnetic and optical properties that depend strongly on their size and geometry. The availability of these materials raises many fundamental questions as weIl as technological possibilities. From the academic viewpoint, the most pertinent question concerns the evolution of the atomic and electronic structure of the system as it grows from micro clusters to crystals. At what stage, for example, does the cluster look as if it is a fragment of the corresponding crystal. How do electrons forming bonds in micro-clusters transform to bands in solids? How do the s...

  20. Availability, reliability and downtime of systems with repairable components

    DEFF Research Database (Denmark)

    Kiureghian, Armen Der; Ditlevsen, Ove Dalager; Song, J.

    2007-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and lower bound reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in...... performance measures with respect to the mean rate of failure and the mean duration of repair of each component. These expressions provide a convenient framework for identifying important components within the system and for decision-making aimed at upgrading the system availability or reliability, or...... time and repair durations are assumed to be exponentially distributed. The results are expressed in terms of the mean rates of failure and mean durations of repair of the individual components. Closed-form expressions are also derived for the rates of change of the various probabilistic system...

  1. Clusters: systems between atoms and solids

    International Nuclear Information System (INIS)

    Atomic and molecular clusters will be discussed here. These are aggregates of atoms and molecules so large that one cannot describe them properly as large molecules. But they are small enough, that the condensed phase properties, if present at all, are not fully developed. This field forms the bridge between the traditional disciplines of atomic or molecular physics on one side and the physics and chemistry of condensed matter on the other side. The number of groups working in this field has increased tremendously in recent years. (Author)

  2. System-Availability And Resource-Allocation Program

    Science.gov (United States)

    Viterna, L. A.; Stalnaker, D. K.

    1995-01-01

    ACARA analyzes availability, life-cycle cost, and scheduling of resources. Uses statistical Monte Carlo method to simulate capacity states of system as well as failure and repair of components. Failures of components modeled mathematically by use of combination of exponential and Weibull probability distributions. Schedules replacement of components to optimize performance of system. Made to comply with any constraints on production of components, capacities of resupply vehicles, spares kept on site, crews, and/or equipment. Written in APL2.

  3. Enforcing Availability in Failure-Aware Communicating Systems

    OpenAIRE

    López-Acosta, Hugo-Andrés; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    Choreographic programming is a programming-language design approach that drives error-safe protocol development in distributed systems. Motivated by challenging scenarios in Cyber-Physical Systems (CPS), we study how choreographic programming can cater for dynamic infrastructures where the availability of components may change at runtime. We introduce the Global Quality Calculus (GCq), a process calculus featuring novel operators for multiparty, partial and collective communications; we provi...

  4. Intelligent Control Scheme of Engineering Machinery of Cluster Hybrid System

    Institute of Scientific and Technical Information of China (English)

    GAO Qiang; WANG Hongli

    2005-01-01

    In a hybrid system, the subsystems with discrete dynamics play a central role in a hybrid system. In the course of engineering machinery of cluster construction, the discrete control law is hard to obtain because the construction environment is complex and there exist many affecting factors. In this paper, hierarchically intelligent control, expert control and fuzzy control are introduced into the discrete subsystems of engineering machinery of cluster hybrid system, so as to rebuild the hybrid system and make the discrete control law easily and effectively obtained. The structures, reasoning mechanism and arithmetic of intelligent control are replanted to discrete dynamic, conti-nuous process and the interface of the hybrid system. The structures of three types of intelligent hybrid system are presented and the human experiences summarized from engineering machinery of cluster are taken into account.

  5. Space Transportation System Availability Requirement and Its Influencing Attributes Relationships

    Science.gov (United States)

    Rhodes, Russell E.; Adams, Timothy C.; McCleskey, Carey M.

    2008-01-01

    It is important that engineering and management accept the need for an availability requirement that is derived with its influencing attributes. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability. Also important to provide bounds of the variables providing engineering the insight required to control the system's engineering solution, e.g., these influencing attributes become design requirements also. These variables will drive the need to provide integration of similar discipline functions or technology selection to allow control of the total parts count. The relationship of selecting a reliability requirement will place a constraint on parts count to achieve a given availability requirement or if allowed to increase the parts count will drive the system reliability requirement higher. They also provide the understanding for the relationship of mean repair time (or mean down time) to maintainability, e.g., accessibility for repair, and both the mean time between failure, e.g., reliability of hardware and availability. The concerns and importance of achieving a strong availability requirement is driven by the need for affordability, the choice of using the two launch solution for the single space application, or the need to control the spare parts count needed to support the long stay in either orbit or on the surface of the moon. Understanding the requirements before starting the architectural design concept will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable

  6. Space Transportation System Availability Requirements and Its Influencing Attributes Relationships

    Science.gov (United States)

    Rhodes, Russell E.; Adams, Timothy C.; McCleskey, Carey M.

    2008-01-01

    It is important that engineering and management accept the need for an availability requirement that is derived with its influencing attributes. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability. Also important to provide bounds of the variables providing engineering the insight required to control the system's engineering solution, e.g., these influencing attributes become design requirements also. These variables will drive the need to provide integration of similar discipline functions or technology selection to allow control of the total parts count. The relationship of selecting a reliability requirement will place a constraint on parts count to achieve a given availability requirement or if allowed to increase the parts count will drive the system reliability requirement higher. They also provide the understanding for the relationship of mean repair time (or mean down time) to maintainability, e.g., accessibility for repair, and both the mean time between failure, e.g., reliability of hardware and availability. The concerns and importance of achieving a strong availability requirement is driven by the need for affordability, the choice of using the two launch solution for the single space application, or the need to control the spare parts count needed to support the long stay in either orbit or on the surface of the moon. Understanding the requirements before starting the architectural design concept will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable

  7. Spent fuel reprocessing system availability definition by process simulation

    International Nuclear Information System (INIS)

    To examine nuclear fuel reprocessing plant operating parameters such as maintainability, reliability, availability, equipment redundancy, and surge storage requirements and their effect on plant throughput, a computer simulation model of integrated HTGR fuel reprocessing plant operations is being developed at General Atomic Company (GA). The simulation methodology and the status of the computer programming completed on reprocessing head end systems is reported

  8. Reliability, Availability, and Maintainability of Intermittently-usedRepairable Systems

    OpenAIRE

    P.S. Rajpal; K.S. Shishodia; G.S. Sekhon

    2007-01-01

    A composite measure comprising linear combination of reliability, availability, andmaintainability (CMRAM) is proposed for an intermittently-used complex repairable system,namely a transport helicopter. The failure data are fitted in Weibull distribution for overlappingintervals of operating time to capture the effect of recent maintenance and other actions. Evaluationof CMRAM is helpful in formulating future operational and maintenance strategies.

  9. THE HST/ACS COMA CLUSTER SURVEY. IV. INTERGALACTIC GLOBULAR CLUSTERS AND THE MASSIVE GLOBULAR CLUSTER SYSTEM AT THE CORE OF THE COMA GALAXY CLUSTER

    International Nuclear Information System (INIS)

    Intracluster stellar populations are a natural result of tidal interactions in galaxy clusters. Measuring these populations is difficult, but important for understanding the assembly of the most massive galaxies. The Coma cluster of galaxies is one of the nearest truly massive galaxy clusters and is host to a correspondingly large system of globular clusters (GCs). We use imaging from the HST/ACS Coma Cluster Survey to present the first definitive detection of a large population of intracluster GCs (IGCs) that fills the Coma cluster core and is not associated with individual galaxies. The GC surface density profile around the central massive elliptical galaxy, NGC 4874, is dominated at large radii by a population of IGCs that extend to the limit of our data (R +4000-5000 (systematic) IGCs out to this radius, and that they make up ∼70% of the central GC system, making this the largest GC system in the nearby universe. Even including the GC systems of other cluster galaxies, the IGCs still make up ∼30%-45% of the GCs in the cluster core. Observational limits from previous studies of the intracluster light (ICL) suggest that the IGC population has a high specific frequency. If the IGC population has a specific frequency similar to high-SN dwarf galaxies, then the ICL has a mean surface brightness of μV ∼ 27 mag arcsec-2 and a total stellar mass of roughly 1012 Msun within the cluster core. The ICL makes up approximately half of the stellar luminosity and one-third of the stellar mass of the central (NGC 4874+ICL) system. The color distribution of the IGC population is bimodal, with blue, metal-poor GCs outnumbering red, metal-rich GCs by a ratio of 4:1. The inner GCs associated with NGC 4874 also have a bimodal distribution in color, but with a redder metal-poor population. The fraction of red IGCs (20%), and the red color of those GCs, implies that IGCs can originate from the halos of relatively massive, L* galaxies, and not solely from the disruption of dwarf

  10. Fuzzy Based Anomaly Intrusion Detection System for Clustered WSN

    OpenAIRE

    Sumathy Murugan; Sundara Rajan, M.

    2015-01-01

    In Wireless Sensor Networks (WSN), the intrusion detection technique may result in increased computational cost, packet loss, performance degradation and so on. In order to overcome these issues, in this study, we propose a fuzzy based anomaly intrusion detection system for clustered WSN. Initially the cluster heads are selected based on the parameters such as link quality, residual energy and coverage. Then the anomaly intrusion is detected using fuzzy logic technique. This technique conside...

  11. Cluster formation in complex multi-scale systems

    OpenAIRE

    Gibbon, J. D.; Titi, E. S.

    2005-01-01

    Based on the competition between members of a hierarchy of length scales in complex multi-scale systems, it is shown how clustering of active quantities into concentrated sets, like bubbles in a Swiss cheese, is a generic property that dominates the intermittent structure. The halo-like surfaces of these clusters have scaling exponents lower than that of their kernels, which can be as high as the domain dimension. Examples include spots in fluid turbulence and droplets in spin-glasses.

  12. Cluster formation in complex multi-scale systems

    CERN Document Server

    Titi, J D G E S

    2005-01-01

    Based on the ordering and competition of length scales in complex multi-scale systems, it is shown how clustering of active quantities into concentrated sets, like bubbles in a Swiss cheese, is a generic property that dominates the intermittent structure. The halo-like surfaces of these clusters have scaling exponents lower than that of their kernels, which can be as high as the domain dimension. Examples, among others, are spots in fluid turbulence and droplets in spin-glasses.

  13. Groundwater availability of the Denver Basin aquifer system, Colorado

    Science.gov (United States)

    Paschke, Suzanne S., (Edited By)

    2011-01-01

    The Denver Basin aquifer system is a critical water resource for growing municipal, industrial, and domestic uses along the semiarid Front Range urban corridor of Colorado. The confined bedrock aquifer system is located along the eastern edge of the Rocky Mountain Front Range where the mountains meet the Great Plains physiographic province. Continued population growth and the resulting need for additional water supplies in the Denver Basin and throughout the western United States emphasize the need to continually monitor and reassess the availability of groundwater resources. In 2004, the U.S. Geological Survey initiated large-scale regional studies to provide updated groundwater-availability assessments of important principal aquifers across the United States, including the Denver Basin. This study of the Denver Basin aquifer system evaluates the hydrologic effects of continued pumping and documents an updated groundwater flow model useful for appraisal of hydrologic conditions.

  14. PHOTOMETRIC PROPERTIES OF THE M33 STAR CLUSTER SYSTEM

    International Nuclear Information System (INIS)

    We present a catalog of 2990 extended sources in a 10 x 10 area centered on M33 using the MegaCam camera on the 3.6 m Canada-France-Hawaii Telescope. The catalog includes 599 new candidate stellar clusters, 204 previously confirmed clusters, 1969 likely background galaxies, and 218 unknown extended objects. We present ugriz integrated magnitudes of the candidates and confirmed star clusters (SCs) as well as the full width at half maximum, ellipticity, and stellarity. Based on the properties of the confirmed SCs, we select a sub-sample of highly probable clusters composed of 246 objects. The integrated photometry of the complete cluster catalog reveals a wide range of colors of -0.4 7 yr) possessing significant nebular emission. Analysis of the radial density distribution suggests that the cluster system of M33 has suffered from significant depletion possibly due to interactions with M31. We also detect a gap in the cluster distribution in the color-color diagram at (g - r) ≅ 0.3 and (u - g) ≅ 0.8. This gap could be interpreted as an evolutionary effect. This complete catalog provides promising targets for deep photometry and high-resolution spectroscopy to study the structure and star formation history of M33.

  15. Probabilistic sensitivity analysis of system availability using Gaussian processes

    International Nuclear Information System (INIS)

    The availability of a system under a given failure/repair process is a function of time which can be determined through a set of integral equations and usually calculated numerically. We focus here on the issue of carrying out sensitivity analysis of availability to determine the influence of the input parameters. The main purpose is to study the sensitivity of the system availability with respect to the changes in the main parameters. In the simplest case that the failure repair process is (continuous time/discrete state) Markovian, explicit formulae are well known. Unfortunately, in more general cases availability is often a complicated function of the parameters without closed form solution. Thus, the computation of sensitivity measures would be time-consuming or even infeasible. In this paper, we show how Sobol and other related sensitivity measures can be cheaply computed to measure how changes in the model inputs (failure/repair times) influence the outputs (availability measure). We use a Bayesian framework, called the Bayesian analysis of computer code output (BACCO) which is based on using the Gaussian process as an emulator (i.e., an approximation) of complex models/functions. This approach allows effective sensitivity analysis to be achieved by using far smaller numbers of model runs than other methods. The emulator-based sensitivity measure is used to examine the influence of the failure and repair densities' parameters on the system availability. We discuss how to apply the methods practically in the reliability context, considering in particular the selection of parameters and prior distributions and how we can ensure these may be considered independent—one of the key assumptions of the Sobol approach. The method is illustrated on several examples, and we discuss the further implications of the technique for reliability and maintenance analysis

  16. Building a Portable File System for Heterogeneous Clusters

    Institute of Scientific and Technical Information of China (English)

    HUANG Qifeng; YANG Guangwen; ZHENG Weimin; SHEN Meiming; DENG Yiyan

    2005-01-01

    Existing in-kernel distributed file systems cannot cope with the higher requirements in well-equipped cluster environments, especially when the system becomes larger and inevitably heterogeneous. TH-CluFS is a cluster file system designed for large heterogeneous systems. TH-CluFS is implemented completely in the user space by emulating the network file system (NFS) V2 server, and is easily portable to other portable operating system interface (POSIX)-compliant platforms with application programming/binary interface API/ABI compliance. In addition, TH-CluFS uses a serverless architecture which flexibly distributes data at file granularity and achieves a consistent file system view from distributed metadata. The global cache makes full use of the aggregated memories and disks in the cluster to optimize system performance. Experimental results suggest that although TH-CluFS is implemented as user-level components, it functions as a portable, single system image, and scalable cluster file system with acceptable performance sacrifices.

  17. GLOBULAR CLUSTER SYSTEMS IN BRIGHTEST CLUSTER GALAXIES: A NEAR-UNIVERSAL LUMINOSITY FUNCTION?

    Energy Technology Data Exchange (ETDEWEB)

    Harris, William E.; O' Halloran, Heather; Cockcroft, Robert, E-mail: harris@physics.mcmaster.ca, E-mail: ohallohm@mcmaster.ca, E-mail: cockcroft@physics.mcmaster.ca [Department of Physics and Astronomy, McMaster University, Hamilton, ON (Canada); and others

    2014-12-20

    We present the first results from our Hubble Space Telescope brightest cluster galaxy (BCG) survey of seven central supergiant cluster galaxies and their globular cluster (GC) systems. We measure a total of 48,000 GCs in all seven galaxies, representing the largest single GC database. We find that a log-normal shape accurately matches the observed the luminosity function (LF) of the GCs down to the globular cluster luminosity function turnover point, which is near our photometric limit. In addition, the LF has a virtually identical shape in all seven galaxies. Our data underscore the similarity in the formation mechanism of massive star clusters in diverse galactic environments. At the highest luminosities (L ≳ 10{sup 7} L {sub ☉}), we find small numbers of ''superluminous'' objects in five of the galaxies; their luminosity and color ranges are at least partly consistent with those of ultra-compact dwarfs. Last, we find preliminary evidence that in the outer halo (R ≳ 20 kpc), the LF turnover point shows a weak dependence on projected distance, scaling as L {sub 0} ∼ R {sup –0.2}, while the LF dispersion remains nearly constant.

  18. QCS : a system for querying, clustering, and summarizing documents.

    Energy Technology Data Exchange (ETDEWEB)

    Dunlavy, Daniel M.

    2006-08-01

    Information retrieval systems consist of many complicated components. Research and development of such systems is often hampered by the difficulty in evaluating how each particular component would behave across multiple systems. We present a novel hybrid information retrieval system--the Query, Cluster, Summarize (QCS) system--which is portable, modular, and permits experimentation with different instantiations of each of the constituent text analysis components. Most importantly, the combination of the three types of components in the QCS design improves retrievals by providing users more focused information organized by topic. We demonstrate the improved performance by a series of experiments using standard test sets from the Document Understanding Conferences (DUC) along with the best known automatic metric for summarization system evaluation, ROUGE. Although the DUC data and evaluations were originally designed to test multidocument summarization, we developed a framework to extend it to the task of evaluation for each of the three components: query, clustering, and summarization. Under this framework, we then demonstrate that the QCS system (end-to-end) achieves performance as good as or better than the best summarization engines. Given a query, QCS retrieves relevant documents, separates the retrieved documents into topic clusters, and creates a single summary for each cluster. In the current implementation, Latent Semantic Indexing is used for retrieval, generalized spherical k-means is used for the document clustering, and a method coupling sentence ''trimming'', and a hidden Markov model, followed by a pivoted QR decomposition, is used to create a single extract summary for each cluster. The user interface is designed to provide access to detailed information in a compact and useful format. Our system demonstrates the feasibility of assembling an effective IR system from existing software libraries, the usefulness of the modularity of

  19. QCS: a system for querying, clustering and summarizing documents.

    Energy Technology Data Exchange (ETDEWEB)

    Dunlavy, Daniel M.; Schlesinger, Judith D. (Center for Computing Sciences, Bowie, MD); O' Leary, Dianne P. (University of Maryland, College Park, MD); Conroy, John M. (Center for Computing Sciences, Bowie, MD)

    2006-10-01

    Information retrieval systems consist of many complicated components. Research and development of such systems is often hampered by the difficulty in evaluating how each particular component would behave across multiple systems. We present a novel hybrid information retrieval system--the Query, Cluster, Summarize (QCS) system--which is portable, modular, and permits experimentation with different instantiations of each of the constituent text analysis components. Most importantly, the combination of the three types of components in the QCS design improves retrievals by providing users more focused information organized by topic. We demonstrate the improved performance by a series of experiments using standard test sets from the Document Understanding Conferences (DUC) along with the best known automatic metric for summarization system evaluation, ROUGE. Although the DUC data and evaluations were originally designed to test multidocument summarization, we developed a framework to extend it to the task of evaluation for each of the three components: query, clustering, and summarization. Under this framework, we then demonstrate that the QCS system (end-to-end) achieves performance as good as or better than the best summarization engines. Given a query, QCS retrieves relevant documents, separates the retrieved documents into topic clusters, and creates a single summary for each cluster. In the current implementation, Latent Semantic Indexing is used for retrieval, generalized spherical k-means is used for the document clustering, and a method coupling sentence 'trimming', and a hidden Markov model, followed by a pivoted QR decomposition, is used to create a single extract summary for each cluster. The user interface is designed to provide access to detailed information in a compact and useful format. Our system demonstrates the feasibility of assembling an effective IR system from existing software libraries, the usefulness of the modularity of the design

  20. THE ACCRETION OF DWARF GALAXIES AND THEIR GLOBULAR CLUSTER SYSTEMS

    International Nuclear Information System (INIS)

    The question of where the low-metallicity globular clusters in early-type galaxies came from has profound implications for the formation of those galaxies. Our work supports the idea that the metal-poor globular cluster systems of giant early-type galaxies formed in dwarf galaxies that have been subsumed by the giants. To support this hypothesis, two linear relations, one involving globular cluster metallicity versus host galaxy luminosity and one involving metallicity versus velocity dispersion were studied. Tentatively, these relations show that the bright ellipticals do not obey the same trend as the dwarfs, suggesting that the low-metallicity globular clusters did not form within their parent bright ellipticals.

  1. Electric energy supply systems: description of available technologies

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhauer, J.L.; Rogers, E.A.; King, J.C.; Stegen, G.E.; Dowis, W.J.

    1985-02-01

    When comparing coal transportation with electric transmission as a means of delivering electric power, it is desirable to compare entire energy systems rather than just the transportation/transmission components because the requirements of each option may affect the requirements of other energy system components. PNL's assessment consists of two parts. The first part, which is the subject of this document, is a detailed description of the technical, cost, resource and environmental characteristics of each system component and technologies available for these components. The second part is a computer-based model that PNL has developed to simulate construction and operation of alternative system configurations and to compare the performance of these systems under a variety of economic and technical conditions. This document consists of six chapters and two appendices. A more thorough description of coal-based electric energy systems is presented in the Introduction and Chapter 1. Each of the subsequent chapters describes technologies for five system components: Western coal resources (Chapter 2), coal transportation (Chapter 3), coal gasification and gas transmission (Chapter 4), and electric power transmission (Chapter 6).

  2. Cluster as a Service for Disaster Recovery in Intercloud Systems: Design and Modeling

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Khoshkholghi

    2014-06-01

    Full Text Available Nowadays, all modern IT technologies aim to create dynamic and flexible environments. For this reason, InterCloud has been designed to provide a vast and flexible virtualized environment in which many clouds can interact with one another in a dynamic way. Disaster recovery is one of the main applications of InterCloud which can be supported by Cluster as a Service. However, the previous studies addressed disaster recovery and Cluster as a Service separately. In addition, system backup and disaster recovery methods are not sufficiently effective in InterCloud. In this paper, we propose an InterCloud system which integrates both Cluster as a Service and disaster recovery in a harmonious manner. Also, we present a heuristic approach to select the best locations for system backup and disaster recovery in InterCloud systems. Finally, the proposed system is modeled and analyzed using Continuous-time Markov chains.

  3. Single Nucleotide Polymorphism Clustering in Systemic Autoimmune Diseases

    Science.gov (United States)

    Charlon, Thomas; Bossini-Castillo, Lara; Carmona, F. David; Di Cara, Alessandro; Wojcik, Jérôme; Voloshynovskiy, Sviatoslav

    2016-01-01

    Systemic Autoimmune Diseases, a group of chronic inflammatory conditions, have variable symptoms and difficult diagnosis. In order to reclassify them based on genetic markers rather than clinical criteria, we performed clustering of Single Nucleotide Polymorphisms. However naive approaches tend to group patients primarily by their geographic origin. To reduce this “ancestry signal”, we developed SNPClust, a method to select large sources of ancestry-independent genetic variations from all variations detected by Principal Component Analysis. Applied to a Systemic Lupus Erythematosus case control dataset, SNPClust successfully reduced the ancestry signal. Results were compared with association studies between the cases and controls without or with reference population stratification correction methods. SNPClust amplified the disease discriminating signal and the ratio of significant associations outside the HLA locus was greater compared to population stratification correction methods. SNPClust will enable the use of ancestry-independent genetic information in the reclassification of Systemic Autoimmune Diseases. SNPClust is available as an R package and demonstrated on the public Human Genome Diversity Project dataset at https://github.com/ThomasChln/snpclust. PMID:27490238

  4. Single Nucleotide Polymorphism Clustering in Systemic Autoimmune Diseases.

    Science.gov (United States)

    Charlon, Thomas; Martínez-Bueno, Manuel; Bossini-Castillo, Lara; Carmona, F David; Di Cara, Alessandro; Wojcik, Jérôme; Voloshynovskiy, Sviatoslav; Martín, Javier; Alarcón-Riquelme, Marta E

    2016-01-01

    Systemic Autoimmune Diseases, a group of chronic inflammatory conditions, have variable symptoms and difficult diagnosis. In order to reclassify them based on genetic markers rather than clinical criteria, we performed clustering of Single Nucleotide Polymorphisms. However naive approaches tend to group patients primarily by their geographic origin. To reduce this "ancestry signal", we developed SNPClust, a method to select large sources of ancestry-independent genetic variations from all variations detected by Principal Component Analysis. Applied to a Systemic Lupus Erythematosus case control dataset, SNPClust successfully reduced the ancestry signal. Results were compared with association studies between the cases and controls without or with reference population stratification correction methods. SNPClust amplified the disease discriminating signal and the ratio of significant associations outside the HLA locus was greater compared to population stratification correction methods. SNPClust will enable the use of ancestry-independent genetic information in the reclassification of Systemic Autoimmune Diseases. SNPClust is available as an R package and demonstrated on the public Human Genome Diversity Project dataset at https://github.com/ThomasChln/snpclust. PMID:27490238

  5. Interference mitigation techniques for clustered multicell joint decoding systems

    Directory of Open Access Journals (Sweden)

    Chatzinotas Symeon

    2011-01-01

    Full Text Available Abstract Multicell joint processing has originated from information-theoretic principles as a means of reaching the fundamental capacity limits of cellular networks. However, global multicell joint decoding is highly complex and in practice clusters of cooperating Base Stations constitute a more realistic scenario. In this direction, the mitigation of intercluster interference rises as a critical factor towards achieving the promised throughput gains. In this paper, two intercluster interference mitigation techniques are investigated and compared, namely interference alignment and resource division multiple access. The cases of global multicell joint processing and cochannel interference allowance are also considered as an upper and lower bound to the interference alignment scheme, respectively. Each case is modelled and analyzed using the per-cell ergodic sum-rate throughput as a figure of merit. In this process, the asymptotic eigenvalue distribution of the channel covariance matrices is analytically derived based on free-probabilistic arguments in order to quantify the sum-rate throughput. Using numerical results, it is established that resource division multiple access is preferable for dense cellular systems, while cochannel interference allowance is advantageous for highly sparse cellular systems. Interference alignment provides superior performance for average to sparse cellular systems on the expense of higher complexity.

  6. Use of Commericially Available Software in an Attribute Measurement System.

    Energy Technology Data Exchange (ETDEWEB)

    MacArthur, D. W. (Duncan W.); Bracken, D. S. (David S.); Carrillo, L. A. (Louis A.); Elmont, T. H. (Timothy H.); Frame, K. C. (Katherine C.); Hirsch, K. L. (Karen L.)

    2005-01-01

    A major issue in international safeguards of nuclear materials is the ability to verify that processes and materials in nuclear facilities are consistent with declaration without revealing sensitive information. An attribute measurement system (AMS) is a non-destructive assay (NDA) system that utilizes an information barrier to protect potentially sensitive information about the measurement item. A key component is the software utilized for operator interface, data collection, analysis, and attribute determination, as well as the operating system under which they are implemented. Historically, custom software has been used almost exclusively in transparency applications, and it is unavoidable that some amount of custom software is needed. The focus of this paper is to explore the extent to which commercially available software may be used and the relative merits.

  7. Use of Commericially Available Software in an Attribute Measurement System

    International Nuclear Information System (INIS)

    A major issue in international safeguards of nuclear materials is the ability to verify that processes and materials in nuclear facilities are consistent with declaration without revealing sensitive information. An attribute measurement system (AMS) is a non-destructive assay (NDA) system that utilizes an information barrier to protect potentially sensitive information about the measurement item. A key component is the software utilized for operator interface, data collection, analysis, and attribute determination, as well as the operating system under which they are implemented. Historically, custom software has been used almost exclusively in transparency applications, and it is unavoidable that some amount of custom software is needed. The focus of this paper is to explore the extent to which commercially available software may be used and the relative merits.

  8. Reliability, maintainability, and availability engineering for integrated community energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.Y.; Mavec, J.; Wolosewicz, R.M.; Calm, J.M.; Chopra, P.S.

    1979-12-01

    The reliability, maintainability, and availability (RMA) engineering methodologies for integrated community energy systems (ICES) are reported. Since the tangible and intangible costs of a system failure may outweigh the benefits of the ICES approaches, RMA consideration must be an integral part of ICES engineering. The effectiveness of system planning and design depends on component reliability information and on forecasts of community load profiles. Supply subsystems must provide sufficient capacity to meet demands in spite of maintenance and unscheduled outages. This allowance is the major task of probabilistic system planning. Because reliability and maintainability performance is partially a random process, probabilistic methodology is required for analysis and comparison. Portions of a community energy system being modified or expanded may already be in use before additional portions reach the design stage. This situation presents an opportunity to extend the RMA assessment of the existing system and to improve the additions that will be made to it. RMA engineering is essential to all phases of planning, design, construction, and operation of ICES. The methodologies presented provide a systematic, disciplined approach to predict and analyze RMA, to determine corrective actions necessary, and to achieve performance goals.

  9. Quality And Safety Management Systems: Joint Action For Certification Of Small Firms In An Industrial Cluster In Brazil

    Directory of Open Access Journals (Sweden)

    Gerolamo, M. C.

    2014-05-01

    Full Text Available This paper presents and discusses a proposal for joint action among small firms in an industrial cluster in Brazil for the certification of quality and safety management systems. It proposes a management system model, the implementation process, and periodic auditing. It is the result of an action-research project developed in a metal-mechanical cluster. Its originality lies mainly in the proposal for a joint action programme for the certification of companies, led by the cluster governance agency, to increase the collective efficiency of a cluster. Despite the obstacles encountered, this proposal can help to reduce the difficulties faced by small businesses in implementing and maintaining management systems, and in the long run to foster a culture of quality and safety management. It also contributes to joint actions within the cluster. The challenge faced by the cluster governance agency is to sustain the certification programme in the long term.

  10. Globular Cluster Systems in Brightest Cluster Galaxies: A Near-Universal Luminosity Function?

    CERN Document Server

    Harris, William E; Gnedin, Oleg Y; O'Halloran, Heather; Blakeslee, John P; Whitmore, Bradley C; Cote, Patrick; Geisler, Douglas; Peng, Eric W; Bailin, Jeremy; Rothberg, Barry; Cockcroft, Robert; DeGraaff, Regina Barber

    2014-01-01

    We present the first results from our HST Brightest Cluster Galaxy (BCG) survey of seven central supergiant cluster galaxies and their globular cluster (GC) systems. We measure a total of 48000 GCs in all seven galaxies, representing the largest single GC database. We find that a log-normal shape accurately matches the observed luminosity function (LF) of the GCs down to the GCLF turnover point, which is near our photometric limit. In addition, the LF has a virtually identical shape in all seven galaxies. Our data underscore the similarity in the formation mechanism of massive star clusters in diverse galactic environments. At the highest luminosities (log L > 10^7 L_Sun) we find small numbers of "superluminous" objects in five of the galaxies; their luminosity and color ranges are at least partly consistent with those of UCDs (Ultra-Compact Dwarfs). Lastly, we find preliminary evidence that in the outer halo (R > 20 kpc), the LF turnover point shows a weak dependence on projected distance, scaling as L_0 ~ R...

  11. System for guiding control clusters in a nuclear reactor

    International Nuclear Information System (INIS)

    Nuclear reactor with reactivity control clusters, each formed by a number of absorbent pins moving vertically through a core plate constituting the upper limit of the reactor core and connected together by radial arms to a common axial control rod, and systems for guiding the control clusters in their movements, out of the core, these systems comprising guide boxes associated respectively with the different control clusters, and within each box, plates allowing discontinuous guidance at intermediate levels for individual pins and radial arms, characterized by the fact that each box contains continuous guide tubes of individual pins connecting two pin passage tubesheets specific to the box, one terminating the box and the second constituting a positioning flange on the said core plate

  12. Experience report: System management at the ALICE HLT cluster

    International Nuclear Information System (INIS)

    The ALICE HLT cluster is responsible for the first analysis and compression of the data from the ALICE experiment at CERN. The processing is performed using hardware accelerators like FPGAs, GPUs and computer nodes with commodity hardware. The mixture of hardware accelerators and several types of nodes causes an increased configuration and system management effort. To handle this effort, we are using a combination of three tools: Chef for the configuration management, Ganglia for the real time monitoring and SysMES for unattended system management, i.e. automatic problem recognition and solution. The tools help to minimize the manpower needed to administrate the cluster by reducing the time needed to recognize and identify problems or even by solving problems automatically. In this talk, we give an insight into our setup and report on the experience we have gained with the heterogeneous, on-line processing cluster during the last four years.

  13. A Novel Automatic Detection System for ECG Arrhythmias Using Maximum Margin Clustering with Immune Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    Bohui Zhu

    2013-01-01

    Full Text Available This paper presents a novel maximum margin clustering method with immune evolution (IEMMC for automatic diagnosis of electrocardiogram (ECG arrhythmias. This diagnostic system consists of signal processing, feature extraction, and the IEMMC algorithm for clustering of ECG arrhythmias. First, raw ECG signal is processed by an adaptive ECG filter based on wavelet transforms, and waveform of the ECG signal is detected; then, features are extracted from ECG signal to cluster different types of arrhythmias by the IEMMC algorithm. Three types of performance evaluation indicators are used to assess the effect of the IEMMC method for ECG arrhythmias, such as sensitivity, specificity, and accuracy. Compared with K-means and iterSVR algorithms, the IEMMC algorithm reflects better performance not only in clustering result but also in terms of global search ability and convergence ability, which proves its effectiveness for the detection of ECG arrhythmias.

  14. Topological cluster analysis reveals the systemic organization of the Caenorhabditis elegans connectome.

    Directory of Open Access Journals (Sweden)

    Yunkyu Sohn

    2011-05-01

    Full Text Available The modular organization of networks of individual neurons interwoven through synapses has not been fully explored due to the incredible complexity of the connectivity architecture. Here we use the modularity-based community detection method for directed, weighted networks to examine hierarchically organized modules in the complete wiring diagram (connectome of Caenorhabditis elegans (C. elegans and to investigate their topological properties. Incorporating bilateral symmetry of the network as an important cue for proper cluster assignment, we identified anatomical clusters in the C. elegans connectome, including a body-spanning cluster, which correspond to experimentally identified functional circuits. Moreover, the hierarchical organization of the five clusters explains the systemic cooperation (e.g., mechanosensation, chemosensation, and navigation that occurs among the structurally segregated biological circuits to produce higher-order complex behaviors.

  15. Fault detection of flywheel system based on clustering and principal component analysis

    Directory of Open Access Journals (Sweden)

    Wang Rixin

    2015-12-01

    Full Text Available Considering the nonlinear, multifunctional properties of double-flywheel with closed-loop control, a two-step method including clustering and principal component analysis is proposed to detect the two faults in the multifunctional flywheels. At the first step of the proposed algorithm, clustering is taken as feature recognition to check the instructions of “integrated power and attitude control” system, such as attitude control, energy storage or energy discharge. These commands will ask the flywheel system to work in different operation modes. Therefore, the relationship of parameters in different operations can define the cluster structure of training data. Ordering points to identify the clustering structure (OPTICS can automatically identify these clusters by the reachability-plot. K-means algorithm can divide the training data into the corresponding operations according to the reachability-plot. Finally, the last step of proposed model is used to define the relationship of parameters in each operation through the principal component analysis (PCA method. Compared with the PCA model, the proposed approach is capable of identifying the new clusters and learning the new behavior of incoming data. The simulation results show that it can effectively detect the faults in the multifunctional flywheels system.

  16. Upgrade of GANIL control system cluster

    International Nuclear Information System (INIS)

    The GANIL control system was based on VAX 32 bit computers connected on a coaxial ethernet network. Since last year we are using an Alpha server with 64 bit Alpha workstations. At the same time the network is moving to twisted pair linked to a HUB concentrator, which is itself connected to the main FDDI ring. Solutions to solve the following problems are presented: the generalization of control graphical interfaces; extensive usage of the data base; the compilation of the more complex units; object programming; adaption to the new materials technologies; migration towards another operating system. Also described is the modification in the network imposed by the supplementary control of SPIRAL

  17. Intrinsic Variability in Multiple Systems and Clusters: Open Questions

    Science.gov (United States)

    Lampens, P.

    2006-04-01

    It is most interesting and rewarding to probe the stellar structure of stars which belong to a system originating from the same parent cloud as this provides additional and more accurate constraints for the models. New results on pulsating components in multiple systems and clusters are beginning to emerge regularly. Based on concrete studies, I will present still unsolved problems and discuss some of the issues which may affect our understanding of the pulsation physics in such systems but also in general.

  18. Availability and outage frequency of repairable parallel unit systems

    International Nuclear Information System (INIS)

    This contribution evolved directly from the application of reliability and maintainability analysis in the design of the Gentilly-2 nuclear power station. This station employs a 600 MWe Candu type pressurized heavy water reactor. During the design stage decisions have to be made regarding the configuration of systems which consists of a number of units in parallel. The criteria used in making these decisions are: safety, economics (capital cost and operating efficiency, reliability and maintainability, which can be expressed numerically as availability and outage frequency). This paper describes a method for analyzing the availability and outage frequency of systems consisting of a number of repairable units in parallel. The method is based on state transition models (a unit, whether it is the operating or the standby unit, can be in either of two states: healthy or in repair; the probability of being in either state is a function of the transition rates between the two states: failure rate and repair rate). The development of computer program Stram is presented, as well as some examples of program output

  19. Innovation through process oriented knowledgemanagement in a regional e-cluster system

    OpenAIRE

    Hansen, Ute

    2005-01-01

    A regional e-cluster system and its cybernetics are characterised by a high degree of complexity which requires a comprehensive strategy. The identification of the key components of this e-cluster system and its interrelationships show that the component "knowledge management” is a critical and decisive process in an e-cluster system. ClusterNet builds the strategic frame for a process oriented knowledge management in a regional e-cluster system. The strategy of knowledge management consists ...

  20. FURTHER DEFINITION OF THE MASS-METALLICITY RELATION IN GLOBULAR CLUSTER SYSTEMS AROUND BRIGHTEST CLUSTER GALAXIES

    International Nuclear Information System (INIS)

    We combine the globular cluster (GC) data for 15 brightest cluster galaxies and use this material to trace the mass-metallicity relations (MMRs) in their globular cluster systems (GCSs). This work extends previous studies which correlate the properties of the MMR with those of the host galaxy. Our combined data sets show a mean trend for the metal-poor subpopulation that corresponds to a scaling of heavy-element abundance with cluster mass Z ∼ M 0.30±0.05. No trend is seen for the metal-rich subpopulation which has a scaling relation that is consistent with zero. We also find that the scaling exponent is independent of the GCS specific frequency and host galaxy luminosity, except perhaps for dwarf galaxies. We present new photometry in (g',i') obtained with Gemini/GMOS for the GC populations around the southern giant ellipticals NGC 5193 and IC 4329. Both galaxies have rich cluster populations which show up as normal, bimodal sequences in the color-magnitude diagram. We test the observed MMRs and argue that they are statistically real, and not an artifact caused by the method we used. We also argue against asymmetric contamination causing the observed MMR as our mean results are no different from other contamination-free studies. Finally, we compare our method to the standard bimodal fitting method (KMM or RMIX) and find our results are consistent. Interpretation of these results is consistent with recent models for GC formation in which the MMR is determined by GC self-enrichment during their brief formation period.

  1. Coupled Cluster Theories for Strongly Correlated Molecular Systems

    Czech Academy of Sciences Publication Activity Database

    Kowalski, K.; Bhaskaran-Nair, K.; Brabec, Jiří; Pittner, Jiří

    Heidelberg: Springer-Verlag Berlin, 2013 - (Avella, A.; Mancini, F.), s. 237-271 ISBN 978-3-642-35106-8 R&D Projects: GA ČR GAP208/11/2222 Institutional support: RVO:61388955 Keywords : coupled cluster theories * strongly correlated molecular systems * computational chemistry Subject RIV: CF - Physical ; Theoretical Chemistry

  2. Cluster Density Matrix Embedding Theory for Quantum Spin Systems

    OpenAIRE

    Fan, Zhuo; Jie, Quanlin

    2015-01-01

    We applied cluster density matrix embedding theory, with some modifications, to a spin lattice system. The reduced density matrix of the impurity cluster is embedded in the bath states, which are a set of block-product states. The ground state of the impurity model is formulated using a variational wave function. We tested this theory in a two-dimensional (2-D) spin-1/2 J1-J2 model for a square lattice. The ground-state energy (GSE) and the location of the phase boundaries agree well with the...

  3. Practical approach on gas pipeline compression system availability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Sidney Pereira dos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Kurz, Rainer; Lubomirsky, Matvey [Solar Turbines, San Diego, CA (United States)

    2009-12-19

    Gas pipeline projects traditionally have been designed based on load factor and steady state flow. This approach exposes project sponsors to project sustainability risks due to potential losses of revenues and transportation contract penalties related to pipeline capacity shortage as consequence of compressor unit's unavailability. Such unavailability should previously be quantified during the design phase. This paper presents a case study and a methodology that highlights the practical benefits of applying Monte Carlo simulation for the compression system availability analysis in conjunction with quantitative risk analysis and economic feasibility study. Project economics main variables and their impacts on the project NPV (Net Present Value) are evaluated with their respective statistics distribution to quantify risk and support decision makers to adopt mitigating measures to guarantee competitiveness while protecting project sponsors from otherwise unpredictable risks. This practical approach is compared to load factor approach and the results are presented and evaluated. (author)

  4. Intrusion Detection System for Mobile Ad - Hoc Network Using Cluster-Based Approach

    Directory of Open Access Journals (Sweden)

    Nisha Dang

    2012-06-01

    Full Text Available Today Mobile Ad-hoc Networks have wide spread use in normal as well as mission critical applications. Mobile ad hoc networks are more likely to be attacked due to lack of infrastructure and no central management. To secure Manets many traditional security solutions like encryption are used but not find to be promising. Intrusion detection system is one of the technologies that provide some goodsecurity solutions. IDS provide monitoring and auditing capabilities to detect any abnormality in security of the system. IDS can be used with clustering algorithms to protect entire cluster from malicious code. Existing clustering algorithms have a drawback of consuming more power and they are associated with routes. The routeestablishment and route renewal affects the clusters and asa consequence, the processing and traffic overhead increases due to instability of clusters. The ad hoc networks are battery and power constraint, and therefore IDS cannot be run on all the nodes. A trusted monitoring node can be deployed to detect and respond against intrusions in time. The proposed simplified clustering scheme has been used to detect intrusions, resulting in high detection rates and low processing and memory overhead irrespective of the routes, connections, traffic types and mobility of nodes inthe network.

  5. Peculiar compact stellar systems in the Fornax cluster

    CERN Document Server

    Wittmann, Carolin; Pasquali, Anna; Hilker, Michael; Grebel, Eva K

    2016-01-01

    We search for hints to the origin and nature of compact stellar systems in the magnitude range of ultracompact dwarf galaxies in deep wide-field imaging data of the Fornax cluster core. We visually investigate a large sample of 355 spectroscopically confirmed cluster members with V-band equivalent magnitudes brighter than -10 mag for faint extended structures. Our data reveal peculiar compact stellar systems, which appear asymmetric or elongated from their outer light distribution. We characterize the structure of our objects by quantifying their core concentration, as well as their outer asymmetry and ellipticity. For the brighter objects of our sample we also investigate their spatial and phase-space distribution within the cluster. We argue that the distorted outer structure alone that is seen for some of our objects, is not sufficient to decide whether these systems have a star cluster or a galaxy origin. However, we find that objects with low core concentration and high asymmetry (or high ellipticity) ar...

  6. Folksonomies and clustering in the collaborative system CiteULike

    International Nuclear Information System (INIS)

    We analyze CiteULike, an online collaborative tagging system where users bookmark and annotate scientific papers. Such a system can be naturally represented as a tri-partite graph whose nodes represent papers, users and tags connected by individual tag assignments. The semantics of tags is studied here, in order to uncover the hidden relationships between tags. We find that the clustering coefficient can be used to analyze the semantical patterns among tags

  7. A RM-Based Static Deployment System for Cluster

    OpenAIRE

    Weiguo Wu; Leiqiang Zhang; Lei Wang; Zhenghua Xue

    2009-01-01

    In this paper, a Reliable-Multicast (RM) based static deployment system for cluster is designed which can be functionally divided into three parts: image capture, image transference, and node configuration. Image capture takes the snapshot of the operating system in the source node. Image transference distributes the captured image to target nodes. Node configuration mainly finishes the configuration of some identified information to target nodes.Applying the technology of Image-Based Install...

  8. Folksonomies and clustering in the collaborative system CiteULike

    OpenAIRE

    Capocci, Andrea; Caldarelli, Guido

    2007-01-01

    We analyze CiteULike, an online collaborative tagging system where users bookmark and annotate scientific papers. Such a system can be naturally represented as a tripartite graph whose nodes represent papers, users and tags connected by individual tag assignments. The semantics of tags is studied here, in order to uncover the hidden relationships between tags. We find that the clustering coefficient reflects the semantical patterns among tags, providing useful ideas for the designing of more ...

  9. A COMPUTER CLUSTER SYSTEM FOR PSEUDO-PARALLEL EXECUTION OF GEANT4 SERIAL APPLICATION

    Directory of Open Access Journals (Sweden)

    Memmo Federici

    2013-12-01

    Full Text Available Simulation of the interactions between particles and matter in studies for developing X-rays detectors generally requires very long calculation times (up to several days or weeks. These times are often a serious limitation for the success of the simulations and for the accuracy of the simulated models. One of the tools used by the scientific community to perform these simulations is Geant4 (Geometry And Tracking [2, 3]. On the best of experience in the design of the AVES cluster computing system, Federici et al. [1], the IAPS (Istituto di Astrofisica e Planetologia Spaziali INAF laboratories were able to develop a cluster computer system dedicated to Geant 4. The Cluster is easy to use and easily expandable, and thanks to the design criteria adopted it achieves an excellent compromise between performance and cost. The management software developed for the Cluster splits the single instance of simulation on the cores available, allowing the use of software written for serial computation to reach a computing speed similar to that obtainable from a native parallel software. The simulations carried out on the Cluster showed an increase in execution time by a factor of 20 to 60 compared to the times obtained with the use of a single PC of medium quality.

  10. Modeling the Formation of Globular Cluster Systems in the Virgo Cluster

    CERN Document Server

    Li, Hui

    2014-01-01

    Globular cluster (GC) systems are some of the oldest and most unique building blocks of galaxies. The mass and chemical composition of GCs preserve the fossil record of the early stages of formation of their host galaxies. The observed distribution of GC colors within massive early-type galaxies in the ACS Virgo Cluster Survey (ACSVCS) reveals a multi-modal shape, which likely corresponds to a multi-modal metallicity distribution. In this paper, we present a simple model for the formation and dynamical disruption of globular clusters that aims to match the ACSVCS data. We test the hypothesis that GCs are formed during major mergers of gas-rich galaxies and inherit the metallicity of their hosts. To trace merger events, we use halo merger trees extracted from a large cosmological N-body simulation. We select 20 halos in the mass range 2*10^{12}-7*10^{13} M_sun and match them to 18 Virgo galaxies with K-band luminosity between 3*10^{10} and 3*10^{11}L_sun. To set the Iron abundances, we use an empirical galaxy ...

  11. Systemic availability and pharmacokinetics of thymol in humans.

    Science.gov (United States)

    Kohlert, Claudia; Schindler, Gernot; März, Reinhard W; Abel, Gudrun; Brinkhaus, Benno; Derendorf, Hartmut; Gräfe, Eva-Ulrike; Veit, Markus

    2002-07-01

    Essential oil compounds such as found in thyme extract are established for the therapy of chronic and acute bronchitis. Various pharmacodynamic activities for thyme extract and the essential thyme oil, respectively, have been demonstrated in vitro, but availability of these compounds in the respective target organs has not been proven. Thus, investigation of absorption, distribution, metabolism, and excretion are necessary to provide the link between in vitro effects and in vivo studies. To determine the systemic availability and the pharmacokinetics of thymol after oral application to humans, a clinical trial was carried out in 12 healthy volunteers. Each subject received a single dose of a Bronchipret TP tablet, which is equivalent to 1.08 mg thymol. No thymol could be detected in plasma or urine. However, the metabolites thymol sulfate and thymol glucuronide were found in urine and identified by LC-MS/MS. Plasma and urine samples were analyzed after enzymatic hydrolysis of the metabolites by headspace solid-phase microextraction prior to GC analysis and flame ionization detection. Thymol sulfate, but not thymol glucuronide, was detectable in plasma. Peak plasma concentrations were 93.1+/-24.5 ng ml(-1) and were reached after 2.0+/-0.8 hours. The mean terminal elimination half-life was 10.2 hours. Thymol sulfate was detectable up to 41 hours after administration. Urinary excretion could be followed over 24 hours. The amount of both thymol sulfate and glucuronide excreted in 24-hour urine was 16.2%+/-4.5% of the dose. PMID:12092740

  12. Plasmon excitations in two-dimensional atomic cluster systems

    Science.gov (United States)

    Yu, Yan-Qin; Yu, Ya-Bin; Xue, Hong-Jie; Wang, Ya-Xin; Chen, Jie

    2016-09-01

    Properties of plasmon excitations in two-dimensional (2D) atomic cluster systems are theoretically studied within an extended Hubbard model. The collective oscillation equations of charge, plasmon eigen-equations and the energy-absorption spectrum formula are presented. The calculated results show that different symmetries of plasmons exist in the cluster systems, and the symmetry of charge distribution in the plasmon resonance originate from the intrinsic symmetry of the corresponding eigen-plasmon modes, but not from the symmetry of applied external fields; however, the plasmon excitation with a certain polarization direction should be excited by the field in this direction, the dipole mode of plasmons can be excited by both uniform and non-uniform fields, but multipole ones cannot be excited by an uniform field. In addition, we show that for a given electron density, plasmon spectra are red-shifted with increasing size of the systems.

  13. Lunar Rocks: Available for Year of the Solar System Events

    Science.gov (United States)

    Allen, J. S.

    2010-12-01

    sections may be use requested for college and university courses where petrographic microscopes are available for viewing. Requestors should contact Ms. Mary Luckey, Education Sample Curator. Email address: mary.k.luckey@nasa.gov NASA also loans sets of Moon rocks for use in classrooms, libraries, museums, and planetariums through the Lunar Sample Education Program. Lunar samples (three soils and three rocks) are encapsulated in a six-inch diameter clear plastic disk. A CD with PowerPoint presentations, analogue samples from Earth, a classroom activity guide, and additional printed material accompany the disks. Educators may qualify for the use of these disks by attending a content and security certification workshop sponsored by NASA's Aerospace Education Services Program (AESP). Contact Ms. Margaret Maher, AESP Director. Email address: mjm67@psu.edu NASA makes these precious samples available for the public and encourages the use of lunar rocks to highlight Year of the Solar System events. Surely these interesting specimens of another world will enhance the experience of all YSS participants so please take advantage of these lunar samples and borrow them for events and classes.

  14. Cluster Bulleticity

    OpenAIRE

    Massey, Richard; Kitching, Thomas D.; Nagai, Daisuke

    2010-01-01

    The unique properties of dark matter are revealed during collisions between clusters of galaxies, like the bullet cluster (1E 0657-56) and baby bullet (MACSJ0025-12). These systems provide evidence for an additional, invisible mass in the separation between the distribution of their total mass, measured via gravitational lensing, and their ordinary 'baryonic' matter, measured via its X-ray emission. Unfortunately, the information available from these systems is limited by th...

  15. Cluster Bulleticity

    OpenAIRE

    Massey, R; Kitching, T.; Nagai, D.

    2010-01-01

    The unique properties of dark matter are revealed during collisions between clusters of galaxies, such as the bullet cluster (1E 0657−56) and baby bullet (MACS J0025−12). These systems provide evidence for an additional, invisible mass in the separation between the distributions of their total mass, measured via gravitational lensing, and their ordinary ‘baryonic’ matter, measured via its X-ray emission. Unfortunately, the information available from these systems is limited by their rarity. C...

  16. Hybrid Personalized Recommender System Using Modified Fuzzy C-Means Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Subhash K. Shinde

    2011-02-01

    Full Text Available Recommender Systems apply machine learning and data mining techniques for filtering unseen information and can predict whether a user would like a given resource. This paper proposes a novel Modified Fuzzy C-means (MFCM clustering algorithm which is used for Hybrid Personalized Recommender System (MFCMHPRS. The proposed system works in two phases. In the first phase, opinions from the users are collected in the form of user-item rating matrix. They are clustered offline using MFCM into predetermined number clusters and stored in a database for future recommendation. In the second phase, the recommendations are generated online for active users using similarity measures by choosing the clusters with good quality rating. We propose coefficient parameter for similarity computation when weighting of the users’ similarity. This helps to get further effectiveness and quality of recommendations for the active users. The experimental results using Iris dataset show that the proposed MFCM performs better than Fuzzy C-means (FCM algorithm. The performance of MFCMHPRS is evaluated using Jester database available on website of California University, Berkeley and compared with fuzzy recommender system (FRS. The results obtained empirically demonstrate that the proposed MFCMHPRS performs superiorly.

  17. ATCOM: Automatically Tuned Collective Communication System for SMP Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Meng-Shiou Wu

    2005-12-17

    Conventional implementations of collective communications are based on point-to-point communications, and their optimizations have been focused on efficiency of those communication algorithms. However, point-to-point communications are not the optimal choice for modern computing clusters of SMPs due to their two-level communication structure. In recent years, a few research efforts have investigated efficient collective communications for SMP clusters. This dissertation is focused on platform-independent algorithms and implementations in this area. There are two main approaches to implementing efficient collective communications for clusters of SMPs: using shared memory operations for intra-node communications, and overlapping inter-node/intra-node communications. The former fully utilizes the hardware based shared memory of an SMP, and the latter takes advantage of the inherent hierarchy of the communications within a cluster of SMPs. Previous studies focused on clusters of SMP from certain vendors. However, the previously proposed methods are not portable to other systems. Because the performance optimization issue is very complicated and the developing process is very time consuming, it is highly desired to have self-tuning, platform-independent implementations. As proven in this dissertation, such an implementation can significantly out-perform the other point-to-point based portable implementations and some platform-specific implementations. The dissertation describes in detail the architecture of the platform-independent implementation. There are four system components: shared memory-based collective communications, overlapping mechanisms for inter-node and intra-node communications, a prediction-based tuning module and a micro-benchmark based tuning module. Each component is carefully designed with the goal of automatic tuning in mind.

  18. WIDE-FIELD MULTIBAND PHOTOMETRY OF GLOBULAR CLUSTER SYSTEMS IN THE FORNAX GALAXY CLUSTER

    International Nuclear Information System (INIS)

    We present wide-field multiband photometry of globular cluster (GC) systems in NGC 1399, NGC 1404, and NGC 1387 located in the central region of the Fornax galaxy cluster. Observation was carried out through U, B, V, and I bands, which marks one of the widest and deepest U-band studies on extragalactic GC systems. The present U-band photometry enables us to significantly reduce the contamination by a factor of two for faint sources (V 0 ∼ 23.5). The main results based on some 2000 GC candidates around NGC 1399, NGC 1404, and NGC 1387 are as follows: (1) the GC system in each galaxy exhibits bimodal color distributions in all colors examined, but the shape of color histograms varies systematically depending on colors; (2) NGC 1399 shows that the mean colors of both blue and red GCs become bluer with increasing galactocentric radius; (3) NGC 1399 shows overabundance of GCs in the directions of NGC 1404 and NGC 1387, indicating their ongoing interactions; and (4) NGC 1399 also exhibits a ∼0.'5 offset between the center of the inner GC distribution and the galaxy's optical center, suggesting that NGC 1399 is not yet dynamically relaxed and may be undergoing merger events.

  19. Decline in available world resources: implications for livestock production systems

    International Nuclear Information System (INIS)

    The world is faced with a triple crisis: climate change, peak oil (the end of inexpensive energy) and global resource depletion. These are interrelated and interactive which makes the subject to be discussed in this paper extremely complex. The certainties are that there will be great changes to contend with in the future in order to produce and deliver food to maintain the present world population, let alone a balanced diet for everyone. The global financial meltdown is seen as having a critical role in determining future animal product strategies. The age of scarce and therefore high energy costs now dawns, and will be marked by the decline of oil and all that depends on it, including financial capital. It heralds large changes in the financial and related political structures. Without rationalization of the use of oil there seems to be little chance of continuing growth in industrialised or developing countries. Inexpensive oil allowed food to be produced cheaply but this will change greatly as oil prices rises create the potential for major disruptions in food availability. Peak oil will affect other resource availabilities. Agriculture has received inexpensive chemicals and fertilisers on which high crop yields have been predicated, including: nitrogenous fertilizers manufactured from natural gas and phosphates reserves which have peaked. The world is now dependent on extracting phosphate fertilizers from low grade rock phosphate at high energy costs. Irrigation waters from aquifers have also been depleted and rivers overused. The advent of peak oil with the ultimate high cost of fuel and therefore power for irrigation will clearly cause a return of vast areas of highly productive crop land back to rain-fed cropping, pasture or desert with major loss of food productivity. Soil erosion and fertiliser run off from cropping systems are also major concerns as tillage and crop management have eroded the top soil of large areas of land that will inevitably lead to

  20. Novel hybrid intrusion detection system for clustered wireless sensor network

    OpenAIRE

    Hichem Sedjelmaci; Mohamed Feham

    2011-01-01

    Wireless sensor network (WSN) is regularly deployed in unattended and hostile environments. The WSN is vulnerable to security threats and susceptible to physical capture. Thus, it is necessary to use effective mechanisms to protect the network. It is widely known, that the intrusion detection is one of the most efficient security mechanisms to protect the network against malicious attacks or unauthorized access. In this paper, we propose a hybrid intrusion detection system for clustered WSN. ...

  1. Interconnection of Clusters of Various Architectures in Grid Systems

    OpenAIRE

    Ovidiu GHERMAN; Ungurean, Ioan; Ştefan G. PENTIUC

    2012-01-01

    The future of computing seems to be parallel. The computers built with general purpose processors are superseded nowadays by systems built around processors with multiple cores that are designed to operate with massive amount of arithmetic operation. And more frequently these processors are able to implement an internal parallelism. A similar step was made by IBM when they proposed that a unit dedicated to arithmetical operations to be used as an accelerator node for a cluster controlled by n...

  2. Decline in available world resources - implications for livestock production systems

    International Nuclear Information System (INIS)

    supplementation that increase feed conversion efficiency, building on such demonstration trials as those of Dolberg and Finlayson to increase beef production in China. Ruminants produce 80 million tonnes of methane annually mostly by animals fed low quality feeds. Improving these feeds reduces methane production per unit of product and utilization of nitrate to replace urea in low protein diets can reduce methane production per animal to almost zero removing the down side of increasing enteric methane production, a major contributor to global warming, as production from ruminants increase. Water the other major resource required for agriculture has also been depleted. Many of the world's large river systems are being drained for urban and industrial water supplies or for irrigated crops before they reach their previous destination. Glacial melt is altering the timing of water availability, particularly where it supplies irrigation water in the dry season. The Ghengetic plains are in grave danger of losing their third rice crop in a year putting 200 million people at risk. Ground water has been exploited using cheap fuel, but many of the large aquifers are now too deep to be economically mined for irrigation, reducing some of the major areas of crop production. Bio-fuel production on the Texas high plain is putting enormous strains on water from the aquifer. Yet bio-fuels produce a huge demand in terms of water pollution. The advent of peak oil will clearly return vast areas of irrigated cropland to rain fed cropping, pasture or desert with major loss of food productivity. Global warming cannot be ignored in any discussion on future agriculture. Increasing sea levels will undoubtedly remove considerable areas of fertile delta and weather patterns will certainly change, leading to at times more intense drought and or flooding rains. Warming also carries with it the risk of decreased crop production as recent research has demonstrated that rice yields decrease by 10% for every

  3. Enforcing Availability in Failure-Aware Communicating Systems

    DEFF Research Database (Denmark)

    López-Acosta, Hugo-Andrés; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    availability of components may change at runtime. We introduce the Global Quality Calculus (GCq), a process calculus featuring novel operators for multiparty, partial and collective communications; we provide a type discipline that controls how partial communications refer only to available components; and we...

  4. AIDEN: A Density Conscious Artificial Immune System for Automatic Discovery of Arbitrary Shape Clusters in Spatial Patterns

    Directory of Open Access Journals (Sweden)

    Vishwambhar Pathak

    2012-11-01

    Full Text Available Recent efforts in modeling of dynamics of the natural immune cells leading to artificial immune systems (AIS have ignited contemporary research interest in finding out its analogies to real world problems. The AIS models have been vastly exploited to develop dependable robust
    solutions to clustering. Most of the traditional clustering methods bear limitations in their capability to detect clusters of arbitrary shapes in a fully unsupervised manner. In this paper the recognition and communication dynamics of T Cell Receptors, the recognizing elements in innate immune
    system, has been modeled with a kernel density estimation method. The model has been shown to successfully discover non spherical clusters in spatial patterns. Modeling the cohesion of the antibodies and pathogens with ‘local influence’ measure inducts comprehensive extension of the
    antibody representation ball (ARB, which in turn corresponds to controlled expansion of clusters and prevents overfitting.

  5. Data Integrity and Availability in Power System Communication Infrastructures

    OpenAIRE

    Vuković, Ognjen

    2013-01-01

    Society is increasingly dependent on the proper functioning of electric power systems. Today's electric power systems rely heavily on information and networking technology in order to achieve efficient and secure operation. Recent initiatives to upgrade power systems into smart grids target an even tighter integration with information and communication technologies in order to enable the integration of renewable energy sources, local and bulk generation and demand response. Therefore for a pr...

  6. Knowledge Management System Architecture for the Industry Cluster

    OpenAIRE

    Sureephong, Pradorn; Chakpitak, Nopasit; Ouzrout, Yacine; Neubert, Gilles; BOURAS, Abdelaziz

    2007-01-01

    Since the concept of the industry cluster was popularized by Porter in 1990, many countries try to improve the competitiveness through industry sector. Not only companies who take part in the cluster but also academic institutes, government agencies, associations, and supportive industries. The more actors involved in the cluster the more knowledge were distributed among the member of cluster. Although, many literatures about cluster explained how knowledge is important for the cluster develo...

  7. Dynamics of two-cluster systems in phase space

    International Nuclear Information System (INIS)

    We present a phase-space representation of quantum state vectors for two-cluster systems. Density distributions in the Fock–Bargmann space are constructed for bound and resonance states of 6,7Li and 7,8Be, provided that all these nuclei are treated within a microscopic two-cluster model. The density distribution in the phase space is compared with those in the coordinate and momentum representations. Bound states realize themselves in a compact area of the phase space, as also do narrow resonance states. We establish the quantitative boundaries of this region in the phase space for the nuclei under consideration. Quantum trajectories are demonstrated to approach their classical limit with increasing energy

  8. Cluster electric spectroscopy of colloid chemical oxyhydrate systems

    CERN Document Server

    Sucharev, Yu I

    2015-01-01

    This monograph deals with the shape of Liesegang operator and its respective phase diagrams of spontaneous surges and analyzed properties of cluster attractors. It describes the influence of pulsation noise or self-organization current of gel systems in a magnetic field on singularities of optic parameters of yttrium oxyhydrate, as well as on kinetic curves of changes in optic density of oxyhydrate systems, sorptive properties of d- and f-elements, and the structural organization of their colloids. This monograph is meant for postgraduate students, magisters, researchers, and those interested

  9. Achieving High Performance Distributed System: Using Grid, Cluster and Cloud Computing

    Directory of Open Access Journals (Sweden)

    Sunil Kr Singh

    2015-02-01

    Full Text Available To increase the efficiency of any task, we require a system that would provide high performance along with flexibilities and cost efficiencies for user. Distributed computing, as we are all aware, has become very popular over the past decade. Distributed computing has three major types, namely, cluster, grid and cloud. In order to develop a high performance distributed system, we need to utilize all the above mentioned three types of computing. In this paper, we shall first have an introduction of all the three types of distributed computing. Subsequently examining them we shall explore trends in computing and green sustainable computing to enhance the performance of a distributed system. Finally presenting the future scope, we conclude the paper suggesting a path to achieve a Green high performance distributed system using cluster, grid and cloud computing

  10. The Role and Issues of Clustering Technique in Designing Maintainable Object Oriented System

    Directory of Open Access Journals (Sweden)

    A. K. Malviya

    2011-02-01

    Full Text Available Object Oriented Software development technique has become very opular and is being used by most of the software development companies. Although maintenance may be turn out to be easierfor Object Oriented System. But it is unlikely that the maintenance burden will be completely disappearing. It has always been a crucial issue for software project developers. Still, maintenance consumes a large portion of software development cost. Therefore it is worthwhileto develop Object Oriented System keeping maintainability as a key issue in design phase. This paper investigates the use of clustering technique of data mining in maintenance of software system using object oriented metrics. The presented work evaluates the K-means clustering method by applying it to the commercial software system. The experimental work of software maintenance for the sample data is being simulated on Matlab.

  11. Computer code for calculating reliability/availability of technical systems

    International Nuclear Information System (INIS)

    Three computer codes are reviewed, which can be applied to reliability analyses of technical systems. They are based on the fault tree and the laws of probability theory. The codes can be used for both non-repairable and repairable systems. The simulation code REMO 79 and the analytical code RELAV are based on the conception that a failure of system components is immediately detected and repaired. The model of the FUPRO2 code provides for failures to be detected and repaired only in periodic functional tests. Apart from code descriptions experience and far-reaching aspects resulting from modularization of the fault trees are summarized. (author)

  12. Availability analysis of the AP600 passive core cooling system

    International Nuclear Information System (INIS)

    The reliability analysis of the AP600 Passive Core Cooling System (PXS) has been done. The fault tree analysis method was used for the quantitative analysis. The PXS can be grouped to several sub-systems i.e.: Reactor Coolant System (RCS) Injection Subsystem, Emergency Core Decay Heat Removal Subsystem, and Containment Sump pH Control Subsystem. The quantitative analysis results indicates that the system unavailability is highly dependent on the valves configuration of the Automatic Depressurization System (ADS). If the ADS valves is arranged in Option-1, the system unavailability is 2.347E-03, this means that the yearly contribution to plant down time can be estimated to be about 20.56 hours per year. Whereas, by using Option-2 of fourth stage ADS valves, the system unavailability is reduced to be 9.877E-04 or 8.65 hours per year and this value is consistent with the allocated goal value (8.0 hours per year). The ADS contributes 66.89% to the system unavailability if it is arranged in Option-1, and will reduced to be about 21.21% if its fourth stages are arranged in Option-2. If the ADS is not included as a subsystem of the PXS (relocate to RCS as a subsystem of RCS), then the PXS unavailability will be reduced to about 7.784E-04 or 6.82 hours per year and this is less then the allocated goal value. The major contributors to the system unavailability are mostly dominated by Stage-4 ADS valves (air piston operated valves and squib valves), inservice testing valves of ADS (solenoid operated valves), solenoid valves of Nitrogen Supply to Accumulator, and Passive Residual Heat Removal actuation valves (air operated valves). Therefore, it is recommended that those valves be analyzed more detail to gain the improvement in its reliability. It is also recommended that the fourth stage of ADS valves should be arranged according to Option-2, i.e. one 10-inch normally open motor operated gate valve in series with one 10-inch normally closed squib valve. (author). 13 refs, 3

  13. Network color management system using a cluster dividing method

    Science.gov (United States)

    Nichogi, Mutsuko; Kanamori, Katsuhiro

    2001-12-01

    Recently the color reproduction of the real objects is becoming more and more important in the field of telemedicine and internet shopping. To reproduce the object's color under the various conditions, the surface spectral reflectance has to be estimated. In this paper we present the novel way to estimate it using conventional 3- band digital camera. Usually the precise estimation of the spectra from the 3-band image is very difficult, as it has metameric black and the simple camera model is not suitable. To improve the estimation accuracy, we propose dividing color space in to clusters and estimating spectra using different model parameters at each cluster. Clusters are set corresponding to the major objects in camera images. Next the estimated spectral image is reproduced on the monitor. When luminance and color temperature of the specified viewing illuminant and the monitor are different, the subject hardly perceives the object's real color. Therefore the image is converted using CIECAM97s. This paper shows the results of simulation using the image of enlarged human's mouth assuming remote consulting with dental clinic. In this system, a dentist can perceive the real color of patient's gums and teeth on the monitor.

  14. Shielding analysis methods available in the scale computational system

    International Nuclear Information System (INIS)

    Computational tools have been included in the SCALE system to allow shielding analysis to be performed using both discrete-ordinates and Monte Carlo techniques. One-dimensional discrete ordinates analyses are performed with the XSDRNPM-S module, and point dose rates outside the shield are calculated with the XSDOSE module. Multidimensional analyses are performed with the MORSE-SGC/S Monte Carlo module. This paper will review the above modules and the four Shielding Analysis Sequences (SAS) developed for the SCALE system. 7 refs., 8 figs

  15. Medical record linkage in health information systems by approximate string matching and clustering

    Directory of Open Access Journals (Sweden)

    Buemi Antoine

    2005-10-01

    Full Text Available Abstract Background Multiplication of data sources within heterogeneous healthcare information systems always results in redundant information, split among multiple databases. Our objective is to detect exact and approximate duplicates within identity records, in order to attain a better quality of information and to permit cross-linkage among stand-alone and clustered databases. Furthermore, we need to assist human decision making, by computing a value reflecting identity proximity. Methods The proposed method is in three steps. The first step is to standardise and to index elementary identity fields, using blocking variables, in order to speed up information analysis. The second is to match similar pair records, relying on a global similarity value taken from the Porter-Jaro-Winkler algorithm. And the third is to create clusters of coherent related records, using graph drawing, agglomerative clustering methods and partitioning methods. Results The batch analysis of 300,000 "supposedly" distinct identities isolates 240,000 true unique records, 24,000 duplicates (clusters composed of 2 records and 3,000 clusters whose size is greater than or equal to 3 records. Conclusion Duplicate-free databases, used in conjunction with relevant indexes and similarity values, allow immediate (i.e.: real-time proximity detection when inserting a new identity.

  16. Determining the impact of a design change on system availability

    International Nuclear Information System (INIS)

    Reliability based approaches together with the use of plant operating experience have an important role in all stages of safety analyses. The assessment and the checking of the nuclear power plant safety is one of the safety principles; its application is intended to lead to the improvement of safety in all the states that have operating nuclear power plants. The applications of probabilistic safety analysis, PSA, studies can be used: -as source for the risk knowledge; - in assessment of plant design; - in accident management -in risk analyses (risk assessment); - in operating applications; - in component maintenance and testing prioritization. The PSA is an efficient system analysis method, which is used to assess the risk of operation of nuclear power plants. The PSA study can be used in order to evaluate the design of a plant, to highlight some design changes, or to evaluate the impact of the design changes implementation. The paper presents a case study regarding the design change of boiler level control station system, by studying the effect of implementation of a design change regarding the motorized valves of the feed water auxiliary circuit. The sensitivity analyses are a part of the probabilistic safety evaluation of the Cernavoda nuclear plant safety. The study presents the sensitivity analysis performed for the following top event: the failure of SG level control station, after loss of BLC or both computers (in case of blackout). The analyzed design change notice (DCN451) consists in the implementation of automatic closure of the auxiliary feedwater motorized valves of the boiler level control stations on a high level signal. Failure criteria appears to be any SG unsupplied, in cooldown, using small flow lines under manual control for a mission time of 24 hours The major function of the BLC system is to maintain the steam generators level as close as it can to the setpoint value, in normal and abnormal operating conditions. The system should operate

  17. FINANCING ASSISTANCE AVAILABLE FOR SMALL PUBLIC WATER SYSTEMS

    Science.gov (United States)

    Many small and very small drinking water systems require repair and upgrading if they are to comply with the Safe Drinking Water Act of 1974 and its amendments. Often, dispersed population makes infracstructure expensive on a per-capita basis. Funding shortages at the federal, ...

  18. Design Optimization of Multi-Cluster Embedded Systems for Real-Time Applications

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo;

    2004-01-01

    We present an approach to design optimization of multi-cluster embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. In this paper, we address design problems which are characteristic to multi-clusters: partitioning of the system functionality into...

  19. Securing recommender systems against shilling attacks using social-based clustering

    KAUST Repository

    Zhang, Xiangliang

    2013-07-01

    Recommender systems (RS) have been found supportive and practical in e-commerce and been established as useful aiding services. Despite their great adoption in the user communities, RS are still vulnerable to unscrupulous producers who try to promote their products by shilling the systems. With the advent of social networks new sources of information have been made available which can potentially render RS more resistant to attacks. In this paper we explore the information provided in the form of social links with clustering for diminishing the impact of attacks. We propose two algorithms, CluTr and WCluTr, to combine clustering with "trust" among users. We demonstrate that CluTr and WCluTr enhance the robustness of RS by experimentally evaluating them on data from a public consumer recommender system Epinions.com. © 2013 Springer Science+Business Media New York & Science Press, China.

  20. Novel hybrid intrusion detection system for clustered wireless sensor network

    CERN Document Server

    Sedjelmaci, Hichem

    2011-01-01

    Wireless sensor network (WSN) is regularly deployed in unattended and hostile environments. The WSN is vulnerable to security threats and susceptible to physical capture. Thus, it is necessary to use effective mechanisms to protect the network. It is widely known, that the intrusion detection is one of the most efficient security mechanisms to protect the network against malicious attacks or unauthorized access. In this paper, we propose a hybrid intrusion detection system for clustered WSN. Our intrusion framework uses a combination between the Anomaly Detection based on support vector machine (SVM) and the Misuse Detection. Experiments results show that most of routing attacks can be detected with low false alarm.

  1. Operational Numerical Weather Prediction systems based on Linux cluster architectures

    International Nuclear Information System (INIS)

    The progress in weather forecast and atmospheric science has been always closely linked to the improvement of computing technology. In order to have more accurate weather forecasts and climate predictions, more powerful computing resources are needed, in addition to more complex and better-performing numerical models. To overcome such a large computing request, powerful workstations or massive parallel systems have been used. In the last few years, parallel architectures, based on the Linux operating system, have been introduced and became popular, representing real high performance-low cost systems. In this work the Linux cluster experience achieved at the Laboratory far Meteorology and Environmental Analysis (LaMMA-CNR-IBIMET) is described and tips and performances analysed

  2. Application of the dynamically allocated virtual clustering management system to emulated tactical network experimentation

    Science.gov (United States)

    Marcus, Kelvin

    2014-06-01

    The U.S Army Research Laboratory (ARL) has built a "Network Science Research Lab" to support research that aims to improve their ability to analyze, predict, design, and govern complex systems that interweave the social/cognitive, information, and communication network genres. Researchers at ARL and the Network Science Collaborative Technology Alliance (NS-CTA), a collaborative research alliance funded by ARL, conducted experimentation to determine if automated network monitoring tools and task-aware agents deployed within an emulated tactical wireless network could potentially increase the retrieval of relevant data from heterogeneous distributed information nodes. ARL and NS-CTA required the capability to perform this experimentation over clusters of heterogeneous nodes with emulated wireless tactical networks where each node could contain different operating systems, application sets, and physical hardware attributes. Researchers utilized the Dynamically Allocated Virtual Clustering Management System (DAVC) to address each of the infrastructure support requirements necessary in conducting their experimentation. The DAVC is an experimentation infrastructure that provides the means to dynamically create, deploy, and manage virtual clusters of heterogeneous nodes within a cloud computing environment based upon resource utilization such as CPU load, available RAM and hard disk space. The DAVC uses 802.1Q Virtual LANs (VLANs) to prevent experimentation crosstalk and to allow for complex private networks. Clusters created by the DAVC system can be utilized for software development, experimentation, and integration with existing hardware and software. The goal of this paper is to explore how ARL and the NS-CTA leveraged the DAVC to create, deploy and manage multiple experimentation clusters to support their experimentation goals.

  3. A Study on System Availability Vs System Administration Efforts with Mathematical Models

    Institute of Scientific and Technical Information of China (English)

    郑建德

    2003-01-01

    Two mathematical models are developed in this paper to study the effectiveness of system administration efforts on the improvement of system availability, based on the assumption that there exists a transitional state for a computer system in operation before it is brought down by some hardware or software problems and with intensified system administration efforts, it is possible to discover and fix the problems in time to bring the system back to normal state before it is down. Markov chain is used to simulate the transition of system states. A conclusion is made that increasing system administration efforts may be a cost-effective way to meet the requirements for moderate improvement on system availability, but higher demand on this aspect still has to be met by advanced technologies.

  4. Energy Efficient Cluster-Based Intrusion Detection System for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Manal Abdullah

    2014-09-01

    Full Text Available Wireless sensor networks (WSNs are network type where sensors are used to collect physical measurements. It has many application areas such as healthcare, weather monitoring and even military applications. Security in this kind of networks is a big concern especially in the applications that required confidentiality and privacy. Therefore, providing a WSN with an intrusion detection system is essential to protect its security from different types of intrusions, cyber-attacks and random faults. Clustering has proven its efficiency in prolong the node as well as the whole WSN lifetime. In this paper we have designed an Intrusion Detection (ID system based on Stable Election Protocol (SEP for clustered heterogeneous WSNs. The benefit of using SEP is that it is a heterogeneous-aware protocol to prolong the time interval before the death of the first node. KDD Cup’99 data set is used as the training data and test data. After normalizing our dataset, we trained the system to detect four types of attacks which are Probe, Dos, U2R and R2L, using 18 features out of the 42 features available in KDD Cup'99 dataset. The research used the K-nearest neighbour (KNN classifier for anomaly detection. The experiments determine K = 5 for best classification and this reveals recognition rate of attacks as 75%. Results are compared with KNN classifier for anomaly detection without using a clustering algorithm.

  5. Color gradients in cooling flow cluster central galaxies and the ionization of cluster emission line systems

    Science.gov (United States)

    Romanishin, W.

    1988-01-01

    Preliminary results are given for a program to measure color gradients in the central galaxies in clusters with a variety of cooling flow rates. The objectives are to search for extended blue continuum regions indicative of star formation, to study the spatial distribution of star formation, and to make a quantitative measure of the amount of light from young stars, which can lead to a measure of the star formation rate (for an assumed initial mass function). Four clusters with large masses and large cluster H-alpha emission fluxes are found to have an excess of blue light concentrated to the centers of the cluster central galaxy. Assumption of a disk IMF leads to the conclusion that the starlight might play a major role in ionizing the emission line gas in these clusters.

  6. Clustering of under-five mortality in Rufiji Health and Demographic Surveillance System in rural Tanzania

    Directory of Open Access Journals (Sweden)

    Josephine Shabani

    2010-08-01

    Full Text Available Background: Less than 5 years remain before the 2015 mark when countries will be evaluated on their achievements for the Millennium Development Goals (MDGs. The MDG 4 and 6 call for a reduction of child mortality by two-thirds and combating malaria, HIV/AIDS, TB, and other diseases, respectively. To accelerate the achievement of these goals, focused allocation of resources and high deployment of cost-effective interventions is paramount. The knowledge of spatial and temporal distribution of diseases is important for health authorities to prioritize and allocate resources. Methods: To identify possible significant clusters, we used SatTScan software, and analyzed 2,745 cases of under-five with 134,099 person-years for the period between 1999and 2008. Mortality rates for every year were calculated, likewise a spatial scan statistic was used to test for clusters of total under-five mortalities in both space and time. Results: A number of significant clusters from space, time, and space–time analysis were identified in several locations for a period of 10 years in the Rufiji Demographic Surveillance Site (RDSS. These locations show that villages within the clusters have an elevated risk of under-five deaths. The spatial analysis identified three significant clusters. The first cluster had only one village, Kibiti A (p<0.05, the second cluster involved five villages (Mtawanya, Pagae, Kibiti A, Machepe, and Kibiti B; p<0.05, the third cluster involved one village, Jaribu Mpakani (p<0.05. A space–time cluster of 10 villages for the period between 1999 and 2002 with a radius of 14.73 km was discovered with the highest risk (RR 1.6, p<0.001. The mortality rates were very high for the years 1999–2002 according to the analysis. The death rates were 33.5, 26.4, 24.1, and 24.9, respectively. Total childhood mortality rates calculated for the period of 10 years were 21.0 per 1,000 person-years. Conclusion: During the 10 years of analysis, mortality

  7. Effect of mesoscopic fluctuations on equation of state in cluster-forming systems

    Directory of Open Access Journals (Sweden)

    A. Ciach

    2012-06-01

    Full Text Available Equation of state for systems with particles self-assembling into aggregates is derived within a mesoscopic theory combining density functional and field-theoretic approaches. We focus on the effect of mesoscopic fluctuations in the disordered phase. The pressure - volume fraction isotherms are calculated explicitly for two forms of the short-range attraction long-range repulsion potential. Mesoscopic fluctuations lead to an increased pressure in each case, except for very small volume fractions. When large clusters are formed, the mechanical instability of the system is present at much higher temperature than found in mean-field approximation. In this case phase separation competes with the formation of periodic phases (colloidal crystals. In the case of small clusters, no mechanical instability associated with separation into dilute and dense phases appears.

  8. Generation of cluster states in optomechanical quantum systems

    Science.gov (United States)

    Houhou, Oussama; Aissaoui, Habib; Ferraro, Alessandro

    2015-12-01

    We consider an optomechanical quantum system composed of a single cavity mode interacting with N mechanical resonators. We propose a scheme for generating continuous-variable graph states of arbitrary size and shape, including the so-called cluster states for universal quantum computation. The main feature of this scheme is that, differently from previous approaches, the graph states are hosted in the mechanical degrees of freedom rather than in the radiative ones. Specifically, via a 2 N -tone drive, we engineer a linear Hamiltonian which is instrumental to dissipatively drive the system to the desired target state. The robustness of this scheme is assessed against finite interaction times and mechanical noise, confirming it as a valuable approach towards quantum state engineering for continuous-variable computation in a solid-state platform.

  9. Cluster Algorithms for General-S Quantum Spin Systems

    International Nuclear Information System (INIS)

    We present a general strategy to extend quantum cluster algorithms for S=1/2 spin systems, such as the loop algorithm, to those with an arbitrary size of spins. The partition function of a high-S spin system is generally represented by the path integral of a S=1/2 model with special boundary conditions in the imaginary-time direction. We introduce additional graphs for the boundary part and give the labeling probability explicitly, which completes the algorithm together with an existing S=1/2 algorithm. As a demonstration, we simulate the integer-spin antiferromagnetic Heisenberg chains. The magnitude of the first excitation gap is estimated to be 0.41048(6), 0.08917(4), and 0.01002(3) for S=1 , 2, and 3, respectively

  10. Renormalized cluster expansion for multiple scattering in disordered systems

    International Nuclear Information System (INIS)

    We study wave propagation in a disordered system of scatterers and derive a renormalized cluster expansion for the optical potential or self-energy of the average wave. We show that in the problem of multiple scattering a repetitive structure of Ornstein-Zernike type may be detected. We derive exact expressions for two elementary constituents of the renormalized scattering series, called the reaction field operator and the short-range connector. These expressions involve sums of integrals of a product of a chain correlation function and a nodal connector. We expect that approximate calculation of the reaction field operator and the short-range connector allows one to find a good approximation to the self-energy, even for high density of scatterers. The theory applies to a wide variety of systems

  11. Cluster formation in disordered systems and nuclear fragmentation

    International Nuclear Information System (INIS)

    We investigate an approach to the description of nuclear fragmentation relying on the concept of disorder which may characterise a fragmenting system of particles interacting by means of two-body short and long range potentials. We introduce different criteria in order to define clusters of bound nucleons. We work out the fragment content of events generated by means of numerical simulations. We analyse the moments of mass and charge distributions and related observables, as well as the energy content of the system. We discuss the outcome of the calculations in terms of the concept of universality which has been introduced in the field of nuclear fragmentation in the framework of percolation models. (orig.)

  12. Cluster Model for Wave-Like Motions of a 2D Vertically Vibrated Granular System

    International Nuclear Information System (INIS)

    The fact that trapezoid clusters exist in 2D vertically vibrated granular systems leads us to construct a cluster model, in which wave-like motions are explained as the result of cluster-plate and cluster-cluster collisions. By analyzing the collision of one cluster with the plate in detail, we deduce a basic equation from velocity relationship, which could be separated into two correlative equations: one relates wave-like motion with exciting acceleration, and we call it the excitation condition; the other relates wavelength with exciting frequency, viz., the dispersion relation. The theoretical results are in agreement with the experimental ones, which supports the idea of the cluster model. Moreover, from the cluster model, we also predict a possibility of abnormal dispersion relation of a 2D granular system. (fundamental areas of phenomenology(including applications))

  13. Proxmox high availability

    CERN Document Server

    Cheng, Simon MC

    2014-01-01

    If you want to know the secrets of virtualization and how to implement high availability on your services, this is the book for you. For those of you who are already using Proxmox, this book offers you the chance to build a high availability cluster with a distributed filesystem to further protect your system from failure.

  14. Performance Enhancement of a Web-Based Picture Archiving and Communication System Using Commercial Off-the-Shelf Server Clusters

    Directory of Open Access Journals (Sweden)

    Yan-Lin Liu

    2014-01-01

    Full Text Available The rapid development of picture archiving and communication systems (PACSs thoroughly changes the way of medical informatics communication and management. However, as the scale of a hospital’s operations increases, the large amount of digital images transferred in the network inevitably decreases system efficiency. In this study, a server cluster consisting of two server nodes was constructed. Network load balancing (NLB, distributed file system (DFS, and structured query language (SQL duplication services were installed. A total of 1 to 16 workstations were used to transfer computed radiography (CR, computed tomography (CT, and magnetic resonance (MR images simultaneously to simulate the clinical situation. The average transmission rate (ATR was analyzed between the cluster and noncluster servers. In the download scenario, the ATRs of CR, CT, and MR images increased by 44.3%, 56.6%, and 100.9%, respectively, when using the server cluster, whereas the ATRs increased by 23.0%, 39.2%, and 24.9% in the upload scenario. In the mix scenario, the transmission performance increased by 45.2% when using eight computer units. The fault tolerance mechanisms of the server cluster maintained the system availability and image integrity. The server cluster can improve the transmission efficiency while maintaining high reliability and continuous availability in a healthcare environment.

  15. IMPLEMENTING ENVIRONMENTAL MANAGEMENT SYSTEMS IN A CLUSTER OF MUNICIPALITIES: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Serena Botta

    2013-01-01

    Full Text Available Local authorities are showing an increasing interest in implementing Environmental Management Systems (EMS according to ISO 14001/EMAS as a tool for better dealing with their environmental issues. However, to improve the status of an environmental component or the efficiency of an environmental service often exceeds the boundaries and the competences of a single municipality; furthermore EMS implementation can require significant human and financial resources which could not be faced by small organizations. In order to cope with the above problems a methodology for implementing an EMS in a cluster of municipalities is presented, with the aim of exploiting the possible synergies for sharing knowledge and resources and creating scaleeconomies to better deal with the environmental issues of the whole territory, both at cluster and at single municipality level. The proposed method was tested in a cluster of 33 small municipalities located in NW Italy, leading to the ISO 14001/EMAS certification of each organization. In this study the main methodological steps for implementing the proposed cluster approach and some significant outcomes of its application in the case study are presented.

  16. Design Optimization of Multi-Cluster Embedded Systems for Real-Time Applications

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo; Izosimov, Viacheslav; Hellring, Magnus; Bridal, Olof

    2004-01-01

    We present an approach to design optimization of multi-cluster embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. In this paper, we address design problems which are characteristic to multi-clusters: partitioning of the system functionality into...... efficient utilization of the system. The developed algorithms are evaluated using extensive experiments and a real-life example....

  17. Proactively Monitoring Departmental Clinical IT Systems with an Open Source Availability System

    OpenAIRE

    Toland, C.; Meenan, C.; Warnock, M; Nagy, P.

    2007-01-01

    The goal of all radiology information technology (IT) support organizations is excellent customer service through the availability of critical clinical information services, such as picture archiving communication systems and radiology information systems. Despite these goals, IT support personnel often act like firefighters, reacting to each problem, but unable to prevent or predict other problems. Proactive support is always more desirable than reactive support. Warning signs may exist well...

  18. High-Availability Monitoring and Big Data: Using Java Clustering and Caching Technologies to Meet Complex Monitoring Scenarios

    CERN Document Server

    Brager, M; Koufakis, E; Martini, R; Suwalska, A

    2014-01-01

    Monitoring and control applications face ever more demanding requirements: as both data sets and data rates continue to increase, non-functional requirements such as performance, availability and maintainability become more important.

  19. Cluster based parallel database management system for data intensive computing

    Institute of Scientific and Technical Information of China (English)

    Jianzhong LI; Wei ZHANG

    2009-01-01

    This paper describes a computer-cluster based parallel database management system (DBMS), InfiniteDB, developed by the authors. InfiniteDB aims at efficiently sup-port data intensive computing in response to the rapid grow-ing in database size and the need of high performance ana-lyzing of massive databases. It can be efficiently executed in the computing system composed by thousands of computers such as cloud computing system. It supports the parallelisms of intra-query, inter-query, intra-operation, inter-operation and pipelining. It provides effective strategies for managing massive databases including the multiple data declustering methods, the declustering-aware algorithms for relational operations and other database operations, and the adaptive query optimization method. It also provides the functions of parallel data warehousing and data mining, the coordinator-wrapper mechanism to support the integration of heteroge-neous information resources on the Internet, and the fault tol-erant and resilient infrastructures. It has been used in many applications and has proved quite effective for data intensive computing.

  20. Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

    Science.gov (United States)

    Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

    2010-01-01

    Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, in a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation; testing results, and other information. Where appropriate, actual performance history was used for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to verify compliance with requirements and to highlight design or performance shortcomings for further decision-making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability and maintainability analysis, and present findings and observation based on analysis leading to the Ground Systems Preliminary Design Review milestone.

  1. Assessment of In-Cloud Enterprise Resource Planning System Performed in a Virtual Cluster

    Directory of Open Access Journals (Sweden)

    Bao Rong Chang

    2015-01-01

    Full Text Available This paper introduces a high-performed high-availability in-cloud enterprise resources planning (in-cloud ERP which has deployed in the virtual machine cluster. The proposed approach can resolve the crucial problems of ERP failure due to unexpected downtime and failover between physical hosts in enterprises, causing operation termination and hence data loss. Besides, the proposed one together with the access control authentication and network security is capable of preventing intrusion hacked and/or malicious attack via internet. Regarding system assessment, cost-performance (C-P ratio, a remarkable cost effectiveness evaluation, has been applied to several remarkable ERP systems. As a result, C-P ratio evaluated from the experiments shows that the proposed approach outperforms two well-known benchmark ERP systems, namely, in-house ECC 6.0 and in-cloud ByDesign.

  2. Cluster Bulleticity

    CERN Document Server

    Massey, Richard; Nagai, Daisuke

    2010-01-01

    The unique properties of dark matter are revealed during collisions between clusters of galaxies, like the bullet cluster (1E 0657-56) and baby bullet (MACSJ0025-12). These systems provide evidence for an additional, invisible mass in the separation between the distribution of their total mass, measured via gravitational lensing, and their ordinary 'baryonic' matter, measured via its X-ray emission. Unfortunately, the information available from these systems is limited by their rarity. Constraints on the properties of dark matter, such as its interaction cross-section, are therefore restricted by uncertainties in the individual systems' impact velocity, impact parameter and orientation with respect to the line of sight. Here we develop a complementary, statistical measurement in which every piece of substructure falling into every massive cluster is treated as a bullet. We define 'bulleticity' as the mean separation between dark matter and ordinary matter, and we measure a positive signal in hydrodynamical si...

  3. Hybrid Personalized Recommender System Using Modified Fuzzy C-Means Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Subhash K. Shinde, Uday V. kulkarni

    2010-12-01

    Full Text Available Recommender Systems apply machine learning and data mining techniques forfiltering unseen information and can predict whether a user would like a givenresource. This paper proposes a novel Modified Fuzzy C-means (MFCMclustering algorithm which is used for Hybrid Personalized RecommenderSystem (MFCMHPRS. The proposed system works in two phases. In the firstphase, opinions from the users are collected in the form of user-item ratingmatrix. They are clustered offline using MFCM into predetermined numberclusters and stored in a database for future recommendation. In the secondphase, the recommendations are generated online for active users usingsimilarity measures by choosing the clusters with good quality rating. Wepropose coefficient parameter for similarity computation when weighting of theusers’ similarity. This helps to get further effectiveness and quality ofrecommendations for the active users. The experimental results using Irisdataset show that the proposed MFCM performs better than Fuzzy C-means(FCM algorithm. The performance of MFCMHPRS is evaluated using Jesterdatabase available on website of California University, Berkeley and comparedwith fuzzy recommender system (FRS. The results obtained empiricallydemonstrate that the proposed MFCMHPRS performs superiorly.

  4. MOLA: a bootable, self-configuring system for virtual screening using AutoDock4/Vina on computer clusters

    Directory of Open Access Journals (Sweden)

    Abreu Rui MV

    2010-10-01

    Full Text Available Abstract Background Virtual screening of small molecules using molecular docking has become an important tool in drug discovery. However, large scale virtual screening is time demanding and usually requires dedicated computer clusters. There are a number of software tools that perform virtual screening using AutoDock4 but they require access to dedicated Linux computer clusters. Also no software is available for performing virtual screening with Vina using computer clusters. In this paper we present MOLA, an easy-to-use graphical user interface tool that automates parallel virtual screening using AutoDock4 and/or Vina in bootable non-dedicated computer clusters. Implementation MOLA automates several tasks including: ligand preparation, parallel AutoDock4/Vina jobs distribution and result analysis. When the virtual screening project finishes, an open-office spreadsheet file opens with the ligands ranked by binding energy and distance to the active site. All results files can automatically be recorded on an USB-flash drive or on the hard-disk drive using VirtualBox. MOLA works inside a customized Live CD GNU/Linux operating system, developed by us, that bypass the original operating system installed on the computers used in the cluster. This operating system boots from a CD on the master node and then clusters other computers as slave nodes via ethernet connections. Conclusion MOLA is an ideal virtual screening tool for non-experienced users, with a limited number of multi-platform heterogeneous computers available and no access to dedicated Linux computer clusters. When a virtual screening project finishes, the computers can just be restarted to their original operating system. The originality of MOLA lies on the fact that, any platform-independent computer available can he added to the cluster, without ever using the computer hard-disk drive and without interfering with the installed operating system. With a cluster of 10 processors, and a

  5. The outer halo globular cluster system of M31 - II. Kinematics

    CERN Document Server

    Veljanoski, J; Ferguson, A M N; Huxor, A P; Cote, P; Irwin, M J; Tanvir, N R; Penarrubia, J; Bernard, E J; Fardal, M; Martin, N F; McConnachie, A; Lewis, G F; Chapman, S C; Ibata, R A; Babul, A

    2014-01-01

    We present a detailed kinematic analysis of the outer halo globular cluster (GC) system of M31. Our basis for this is a set of new spectroscopic observations for 78 clusters lying at projected distances between Rproj ~20-140 kpc from the M31 centre. These are largely drawn from the recent PAndAS globular cluster catalogue; 63 of our targets have no previous velocity data. Via a Bayesian maximum likelihood analysis we find that GCs with Rproj > 30 kpc exhibit coherent rotation around the minor optical axis of M31, in the same direction as more centrally- located GCs, but with a smaller amplitude of 86+/-17 km s-1. There is also evidence that the velocity dispersion of the outer halo GC system decreases as a function of projected distance from the M31 centre, and that this relation can be well described by a power law of index ~ -0.5. The velocity dispersion profile of the outer halo GCs is quite similar to that of the halo stars, at least out to the radius up to which there is available information on the stel...

  6. Schedulability-Driven Partitioning and Mapping for Multi-Cluster Real-Time Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo;

    2004-01-01

    , responsible for routing inter-cluster traffic. Based on this analysis, we address design problems which are characteristic to multi-clusters: partitioning of the system functionality into time-triggered and event-triggered domains, and process mapping. We present a branch and bound algorithm for solving......We present an approach to partitioning and mapping for multi-cluster embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. We have proposed a schedulability analysis for such systems, including a worst-case queuing delay analysis for the gateways...

  7. Schedulability-Driven Partitioning and Mapping for Multi-Cluster Real-Time Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    , responsible for routing inter-cluster traffic. Based on this analysis, we address design problems which are characteristic to multi-clusters: partitioning of the system functionality into time-triggered and event-triggered domains, and process mapping. We present a branch and bound algorithm for solving......We present an approach to partitioning and mapping for multi-cluster embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. We have proposed a schedulability analysis for such systems, including a worst-case queuing delay analysis for the gateways...

  8. Using an MPI Cluster in the Control of a Mobile Robots System

    OpenAIRE

    Mohamed Salim LMIMOUNI; Saïd BENAISSA; Hicham Medromi; Adil SAYOUTI

    2014-01-01

    Recently, HPC (High Performance Computing) systems have gone from supercomputers to clusters. The clusters are used in all tasks that require very high computing power such as weather forecasting, climate research, molecular modeling, physical simulations, cryptanalysis, etc. The use of clusters is increasingly important in the scientific community, where the need for high performance computing (HPC) is still growing. In this paper, we propose an improvement of a mobile robots system control ...

  9. Clustering-based urbanisation to improve enterprise information systems agility

    Science.gov (United States)

    Imache, Rabah; Izza, Said; Ahmed-Nacer, Mohamed

    2015-11-01

    Enterprises are daily facing pressures to demonstrate their ability to adapt quickly to the unpredictable changes of their dynamic in terms of technology, social, legislative, competitiveness and globalisation. Thus, to ensure its place in this hard context, enterprise must always be agile and must ensure its sustainability by a continuous improvement of its information system (IS). Therefore, the agility of enterprise information systems (EISs) can be considered today as a primary objective of any enterprise. One way of achieving this objective is by the urbanisation of the EIS in the context of continuous improvement to make it a real asset servicing enterprise strategy. This paper investigates the benefits of EISs urbanisation based on clustering techniques as a driver for agility production and/or improvement to help managers and IT management departments to improve continuously the performance of the enterprise and make appropriate decisions in the scope of the enterprise objectives and strategy. This approach is applied to the urbanisation of a tour operator EIS.

  10. The dynamical importance of binary systems in young massive star clusters

    CERN Document Server

    de Grijs, Richard; Geller, Aaron M

    2015-01-01

    Characterization of the binary fractions in star clusters is of fundamental importance for many fields in astrophysics. Observations indicate that the majority of stars are found in binary systems, while most stars with masses greater than $0.5 M_\\odot$ are formed in star clusters. In addition, since binaries are on average more massive than single stars, in resolved star clusters these systems are thought to be good tracers of (dynamical) mass segregation. Over time, dynamical evolution through two-body relaxation will cause the most massive objects to migrate to the cluster center, while the relatively lower-mass objects remain in or migrate to orbits at greater radii. This process will globally dominate a cluster's stellar distribution. However, close encounters involving binary systems may disrupt `soft' binaries. This process will occur more frequently in a cluster's central, dense region than in its periphery, which may mask the effects of mass segregation. Using high resolution Hubble Space Telescope o...

  11. MAPPING DIFFERENTIAL REDDENING IN THE INNER GALACTIC GLOBULAR CLUSTER SYSTEM

    International Nuclear Information System (INIS)

    A serious limitation in the study of many globular clusters-especially those located near the Galactic center-has been the existence of large and differential extinction by foreground dust. In a series of papers, we intend to map the differential extinction and remove its effects, using a new dereddening technique, in a sample of clusters in the direction of the inner Galaxy, observed using the Magellan 6.5 m telescope and the Hubble Space Telescope. These observations and their analysis will let us produce high-quality color-magnitude diagrams of these poorly studied clusters that will allow us to determine these clusters' relative ages, distances, and chemistry and to address important questions about the formation and the evolution of the inner Galaxy. We also intend to use the maps of the differential extinction to sample and characterize the interstellar medium along the numerous low-latitude lines of sight where the clusters in our sample lie. In this first paper, we describe in detail our dereddening method along with the powerful statistics tools that allow us to apply it, and we show the kind of results that we can expect, applying the method to M62, one of the clusters in our sample. The width of the main sequence and lower red giant branch narrows by a factor of two after applying our dereddening technique, which will significantly help to constrain the age, distance, and metallicity of the cluster.

  12. Customized recommendations for production management clusters of North American automatic milking systems.

    Science.gov (United States)

    Tremblay, Marlène; Hess, Justin P; Christenson, Brock M; McIntyre, Kolby K; Smink, Ben; van der Kamp, Arjen J; de Jong, Lisanne G; Döpfer, Dörte

    2016-07-01

    Automatic milking systems (AMS) are implemented in a variety of situations and environments. Consequently, there is a need to characterize individual farming practices and regional challenges to streamline management advice and objectives for producers. Benchmarking is often used in the dairy industry to compare farms by computing percentile ranks of the production values of groups of farms. Grouping for conventional benchmarking is commonly limited to the use of a few factors such as farms' geographic region or breed of cattle. We hypothesized that herds' production data and management information could be clustered in a meaningful way using cluster analysis and that this clustering approach would yield better peer groups of farms than benchmarking methods based on criteria such as country, region, breed, or breed and region. By applying mixed latent-class model-based cluster analysis to 529 North American AMS dairy farms with respect to 18 significant risk factors, 6 clusters were identified. Each cluster (i.e., peer group) represented unique management styles, challenges, and production patterns. When compared with peer groups based on criteria similar to the conventional benchmarking standards, the 6 clusters better predicted milk produced (kilograms) per robot per day. Each cluster represented a unique management and production pattern that requires specialized advice. For example, cluster 1 farms were those that recently installed AMS robots, whereas cluster 3 farms (the most northern farms) fed high amounts of concentrates through the robot to compensate for low-energy feed in the bunk. In addition to general recommendations for farms within a cluster, individual farms can generate their own specific goals by comparing themselves to farms within their cluster. This is very comparable to benchmarking but adds the specific characteristics of the peer group, resulting in better farm management advice. The improvement that cluster analysis allows for is

  13. Co-evolution of galactic nuclei and globular cluster systems

    International Nuclear Information System (INIS)

    We revisit the hypothesis that dense galactic nuclei are formed from inspiraling globular clusters. Recent advances in the understanding of the continuous formation of globular clusters over cosmic time and the concurrent evolution of the galaxy stellar distribution allow us to construct a simple model that matches the observed spatial and mass distributions of clusters in the Galaxy and the giant elliptical galaxy M87. In order to compare with observations, we model the effects of dynamical friction and dynamical evolution, including stellar mass loss, tidal stripping of stars, and tidal disruption of clusters by the growing galactic nucleus. We find that inspiraling globular clusters form a dense central structure, with mass and radius comparable to the typical values in observed nuclear star clusters (NSCs) in late-type and low-mass early-type galaxies. The density contrast associated with the NSC is less pronounced in giant elliptical galaxies. Our results indicate that the NSC mass as a fraction of mass of the galaxy stellar spheroid scales as MNSC/M∗≈0.0025 M∗,11−0.5. Thus disrupted globular clusters could contribute most of the mass of NSCs in galaxies with stellar mass below 1011 M ☉. The inner part of the accumulated cluster may seed the growth of a central black hole via stellar dynamical core collapse, thereby relieving the problem of how to form luminous quasars at high redshift. The seed black hole may reach ∼105 M ☉ within ≲ 1 Gyr of the beginning of globular cluster formation.

  14. The impact of galaxy harassment on the globular cluster systems of early-type cluster dwarf galaxies

    CERN Document Server

    Smith, Rory; Fellhauer, Michael; Puzia, Thomas H; Aguerri, J A L; Farias, Juan-Pablo

    2012-01-01

    The dynamics of globular cluster systems (GCSs) around galaxies are often used to assess the total enclosed mass, and even to constrain the dark matter distribution. The globular cluster system of a galaxy is typically assumed to be in dynamical equilibrium within the potential of the host galaxy. However cluster galaxies are subjected to a rapidly evolving and, at times, violently destructive tidal field. We investigate the impact of the harassment on the dynamics of GCs surrounding early type cluster dwarfs, using numerical simulations. We find that the dynamical behaviour of the GCS is strongly influenced by the fraction of bound dark matter f_{DM} remaining in the galaxy. Only when f_{DM} falls to ~15%, do stars and GCs begin to be stripped. Still the observed GC velocity dispersion can be used to measure the true enclosed mass to within a factor of 2, even when f_{DM} falls as low as ~3%. This is possible partly because unbound GCs quickly separate from the galaxy body. However even the distribution of {...

  15. Metallicity distributions of globular cluster systems in galaxies

    CERN Document Server

    Eerik, H; Eerik, Helina; Tenjes, Peeter

    2002-01-01

    We collected a sample of 100 galaxies for which different observers have determined colour indices of globular cluster candidates. The sample includes representatives of galaxies of various morphological types and different luminosities. Colour indices (in most cases (V-I), but also (B-I) and (C-T1)) were transformed into metallicities [Fe/H] according to a relation by Kissler-Patig (1998). These data were analysed with the KMM software in order to estimate similarity of the distribution with uni- or bimodal Gaussian distribution. We found that 45 of 100 systems have bimodal metallicity distributions. Mean metallicity of the metal-poor component for these galaxies is = -1.40\\pm 0.02, of the metal-rich component = -0.69 \\pm 0.03. Dispersions of the distributions are 0.15 and 0.18, respectively. Distribution of unimodal metallicities is rather wide. These data will be analysed in a subsequent paper in order to find correlations with parameters of galaxies and galactic environment.

  16. Metallicity distributions of globular cluster systems in galaxies

    Science.gov (United States)

    Eerik, H.; Tenjes, P.

    We collected a sample of 100 galaxies for which different observers have determined colour indices of globular cluster candidates. The sample includes representatives of galaxies of various morphological types and different luminosities. Colour indices (in most cases (V-I), but also (B-I) and (C-T_1)) were transformed into metallicities [Fe/H] according to a relation by Kissler-Patig (1998). These data were analysed with the KMM software in order to estimate similarity of the distribution with uni- or bimodal Gaussian distribution. We found that 45 of 100 systems have bimodal metallicity distributions. Mean metallicity of the metal-poor component for these galaxies is = -1.40 +/- 0.02, of the metal-rich component = -0.69 +/- 0.03. Dispersions of the distributions are 0.15 and 0.18, respectively. Distribution of unimodal metallicities is rather wide. These data will be analysed in a subsequent paper in order to find correlations with parameters of galaxies and galactic environment.

  17. How the Pauli principle governs the decay of three-cluster systems

    OpenAIRE

    Lashko, Yuliya; Filippov, Gennady

    2007-01-01

    New approach to the problem of multichannel continuum spectrum of three-cluster systems composed of an s-cluster and two neutrons is suggested based on the discrete representation of a complete basis of allowed states of the multiparticle harmonic oscillator. The structure of the eigenfunctions and behavior of the eigenvalues of the three-cluster norm kernel are analyzed. Classification of the eigenvalues of the three-cluster systems with the help of eigenvalues of the two-body subsystem is s...

  18. Autonomic Cluster Management System (ACMS): A Demonstration of Autonomic Principles at Work

    Science.gov (United States)

    Baldassari, James D.; Kopec, Christopher L.; Leshay, Eric S.; Truszkowski, Walt; Finkel, David

    2005-01-01

    Cluster computing, whereby a large number of simple processors or nodes are combined together to apparently function as a single powerful computer, has emerged as a research area in its own right. The approach offers a relatively inexpensive means of achieving significant computational capabilities for high-performance computing applications, while simultaneously affording the ability to. increase that capability simply by adding more (inexpensive) processors. However, the task of manually managing and con.guring a cluster quickly becomes impossible as the cluster grows in size. Autonomic computing is a relatively new approach to managing complex systems that can potentially solve many of the problems inherent in cluster management. We describe the development of a prototype Automatic Cluster Management System (ACMS) that exploits autonomic properties in automating cluster management.

  19. The complex star cluster system of NGC 1316 (Fornax A)

    CERN Document Server

    Sesto, Leandro A; Forte, Juan C

    2016-01-01

    This paper presents Gemini-$gri'$ high quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the presence of four stellar cluster populations with distinctive features in terms of age, chemical abundance and spatial distribution. Two of them seem to be the usually old (metal poor and metal rich) populations typically found in elliptical galaxies. In turn, an intermediate-age (5 Gyr) globular cluster population is the dominant component of the sample (as reported by previous papers). We also find a younger cluster population with a tentative age of $\\approx$ 1 Gyr.

  20. Three Systems of Insular Functional Connectivity Identified with Cluster Analysis

    OpenAIRE

    Deen, Ben; Pitskel, Naomi B.; Kevin A. Pelphrey

    2010-01-01

    Despite much research on the function of the insular cortex, few studies have investigated functional subdivisions of the insula in humans. The present study used resting-state functional connectivity magnetic resonance imaging (MRI) to parcellate the human insular lobe based on clustering of functional connectivity patterns. Connectivity maps were computed for each voxel in the insula based on resting-state functional MRI (fMRI) data and segregated using cluster analysis. We identified 3 ins...

  1. Clustered chimera states in delay coupled oscillator systems

    OpenAIRE

    Sethia, Gautam C.; Sen, Abhijit; Atay, Fatihcan M

    2008-01-01

    We investigate "chimera" states in a ring of identical phase oscillators coupled in a time-delayed and spatially non-local fashion. We find novel "clustered chimera" states that have spatially distributed phase coherence separated by incoherence with adjacent coherent regions in anti-phase. The existence of such time-delay induced phase clustering is further supported through solutions of a generalized functional self-consistency equation of the mean field. Our results highlight an additional...

  2. Optimum Availability of Standalone Photovoltaic Power Systems for Remote Housing Electrification

    Directory of Open Access Journals (Sweden)

    Tamer Khatib

    2014-01-01

    Full Text Available The availability of PV systems is discussed to determine the optimum availability at which standalone PV systems must be designed. Optimization methods and PV systems software, such as HOMER and PV.MY, were used for this purpose. Six PV systems with six availability levels were analyzed, in terms of wasted energy, cost of energy, battery usage, and power shortages, using real meteorological data. Results show that PV systems with 99% availability are recommended, because of their high reliability and favorably wasted energy.

  3. AVES: A Computer Cluster System approach for INTEGRAL Scientific Analysis

    Science.gov (United States)

    Federici, M.; Martino, B. L.; Natalucci, L.; Umbertini, P.

    The AVES computing system, based on an "Cluster" architecture is a fully integrated, low cost computing facility dedicated to the archiving and analysis of the INTEGRAL data. AVES is a modular system that uses the software resource manager (SLURM) and allows almost unlimited expandibility (65,536 nodes and hundreds of thousands of processors); actually is composed by 30 Personal Computers with Quad-Cores CPU able to reach the computing power of 300 Giga Flops (300x10{9} Floating point Operations Per Second), with 120 GB of RAM and 7.5 Tera Bytes (TB) of storage memory in UFS configuration plus 6 TB for users area. AVES was designed and built to solve growing problems raised from the analysis of the large data amount accumulated by the INTEGRAL mission (actually about 9 TB) and due to increase every year. The used analysis software is the OSA package, distributed by the ISDC in Geneva. This is a very complex package consisting of dozens of programs that can not be converted to parallel computing. To overcome this limitation we developed a series of programs to distribute the workload analysis on the various nodes making AVES automatically divide the analysis in N jobs sent to N cores. This solution thus produces a result similar to that obtained by the parallel computing configuration. In support of this we have developed tools that allow a flexible use of the scientific software and quality control of on-line data storing. The AVES software package is constituted by about 50 specific programs. Thus the whole computing time, compared to that provided by a Personal Computer with single processor, has been enhanced up to a factor 70.

  4. A Novel Automatic Detection System for ECG Arrhythmias Using Maximum Margin Clustering with Immune Evolutionary Algorithm

    OpenAIRE

    Bohui Zhu; Yongsheng Ding; Kuangrong Hao

    2013-01-01

    This paper presents a novel maximum margin clustering method with immune evolution (IEMMC) for automatic diagnosis of electrocardiogram (ECG) arrhythmias. This diagnostic system consists of signal processing, feature extraction, and the IEMMC algorithm for clustering of ECG arrhythmias. First, raw ECG signal is processed by an adaptive ECG filter based on wavelet transforms, and waveform of the ECG signal is detected; then, features are extracted from ECG signal to cluster different types of ...

  5. Study on Construction of Knowledge Management System Based on Enhancing Core Competence of Industrial Clusters

    OpenAIRE

    Zhenfeng Chen; Xiangzhen Xu

    2010-01-01

    Under the background of the knowledge economy and globalization, knowledge becomes the firm's strategic resources, enhancing the core competence of industrial clusters requires knowledge management. In this paper, firstly, the connotation of the core competence of industrial clusters is analyzed. The mechanism of knowledge management affecting the core competence of industrial clusters is studied. Finally, the knowledge management system that helps to enhance the core competence of industrial...

  6. Faddeev type of equations for three-cluster systems with full treatment of the Pauli principle

    International Nuclear Information System (INIS)

    We analyze peculiarities of the Pauli principle in three-cluster system. We demonstrated that the antisymmetrization operator, being a source of the three-body interaction, can be decomposed into components involving either permutations between all three clusters, or permutations between two clusters only. Introducing this into the Faddeev equations, one obtains three alternative but equivalent formulations. These sets of equations are presented in operator form, for practical applications we will make use full set of the oscillator functions

  7. Cluster Consensus of Nonlinearly Coupled Multi-Agent Systems in Directed Graphs

    Science.gov (United States)

    Lu, Xiao-Qing; Francis, Austin; Chen, Shi-Hua

    2010-05-01

    We investigate the cluster consensus problem in directed networks of nonlinearly coupled multi-agent systems by using pinning control. Depending on the community structure generated by the group partition of the underlying digraph, various clusters can be made coherently independent by applying feedback injections to a fraction of the agents. Sufficient conditions for cluster consensus are obtained using algebraic graph theory and matrix theory and some simulations results are included to illustrate the method.

  8. Kadeploy3: Efficient and Scalable Operating System Provisioning for HPC Clusters

    OpenAIRE

    Jeanvoine, Emmanuel; Sarzyniec, Luc; Nussbaum, Lucas

    2012-01-01

    Operating system provisioning is a common and critical task in cluster computing environments. The required low-level operations involved in provisioning can drastically decrease the performance of a given solution, and maintaining a reasonable provisioning time on clusters of 1000+ nodes is a significant challenge. We present Kadeploy3, a tool built to efficiently and reliably deploy a large number of cluster nodes. Since it is a keystone of the Grid'5000 experimental testbed, it has been de...

  9. Tourism Cluster Competitiveness and Sustainability: Proposal for a Systemic Model to Measure the Impact of Tourism on Local Development

    Directory of Open Access Journals (Sweden)

    Sieglinde Kindl da Cunha

    2005-07-01

    Full Text Available This article proposes a model to measure tourism cluster impact on local development with a view to assessing tourism cluster interaction, competitiveness and sustainability impacts on the economy, society and the environment. The theoretical basis for this model is founded on cluster concept and typology adapting and integrating the systemic competitiveness and sustainability concepts within economic, social, cultural, environmental and political dimensions. The proposed model shows a holistic, multidisciplinary and multi-sector view of local development brought back through a systemic approach to the concepts of competitiveness, social equity and sustainability. Its results make possible strategic guidance to agents responsible for public sector tourism policies, as well as the strategies for competitiveness, competition, cooperation and sustainability in private companies and institutions.

  10. Cluster Symmetries and Dynamics

    Directory of Open Access Journals (Sweden)

    Freer Martin

    2016-01-01

    Full Text Available Many light nuclei display behaviour that indicates that rather than behaving as an A-body systems, the protons and neutrons condense into clusters. The α-particle is the most obvious example of such clustering. This contribution examines the role of such α-clustering on the structure, symmetries and dynamics of the nuclei 8Be, 12C and 16O, recent experimental measurements and future perspectives.

  11. Question Processing and Clustering in INDOC: A Biomedical Question Answering System

    Directory of Open Access Journals (Sweden)

    Ankush Mittal

    2007-12-01

    Full Text Available The exponential growth in the volume of publications in the biomedical domain has made it impossible for an individual to keep pace with the advances. Even though evidence-based medicine has gained wide acceptance, the physicians are unable to access the relevant information in the required time, leaving most of the questions unanswered. This accentuates the need for fast and accurate biomedical question answering systems. In this paper we introduce INDOC—a biomedical question answering system based on novel ideas of indexing and extracting the answer to the questions posed. INDOC displays the results in clusters to help the user arrive the most relevant set of documents quickly. Evaluation was done against the standard OHSUMED test collection. Our system achieves high accuracy and minimizes user effort.

  12. Question Processing and Clustering in INDOC: A Biomedical Question Answering System

    Directory of Open Access Journals (Sweden)

    Sondhi Parikshit

    2007-01-01

    Full Text Available The exponential growth in the volume of publications in the biomedical domain has made it impossible for an individual to keep pace with the advances. Even though evidence-based medicine has gained wide acceptance, the physicians are unable to access the relevant information in the required time, leaving most of the questions unanswered. This accentuates the need for fast and accurate biomedical question answering systems. In this paper we introduce INDOC—a biomedical question answering system based on novel ideas of indexing and extracting the answer to the questions posed. INDOC displays the results in clusters to help the user arrive the most relevant set of documents quickly. Evaluation was done against the standard OHSUMED test collection. Our system achieves high accuracy and minimizes user effort.

  13. THE RICH GLOBULAR CLUSTER SYSTEM OF ABELL 1689 AND THE RADIAL DEPENDENCE OF THE GLOBULAR CLUSTER FORMATION EFFICIENCY

    Energy Technology Data Exchange (ETDEWEB)

    Alamo-Martínez, K. A.; González-Lópezlira, R. A. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58090 (Mexico); Blakeslee, J. P.; Côté, P.; Ferrarese, L. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jee, M. J. [Department of Physics, University of California, Davis, One Shields Avenue, Davis, CA 95616 (United States); Jordán, A. [Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, 7820436 Macul, Santiago (Chile); Meurer, G. R. [International Centre for Radio Astronomy Research, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Peng, E. W. [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); West, M. J., E-mail: k.alamo@crya.unam.mx [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago (Chile)

    2013-09-20

    We study the rich globular cluster (GC) system in the center of the massive cluster of galaxies Abell 1689 (z = 0.18), one of the most powerful gravitational lenses known. With 28 Hubble Space Telescope/Advanced Camera for Surveys orbits in the F814W bandpass, we reach a magnitude I{sub 814} = 29 with ∼>90% completeness and sample the brightest ∼5% of the GC system. Assuming the well-known Gaussian form of the GC luminosity function (GCLF), we estimate a total population of N{sup total}{sub GC}= 162,850{sup +75,450}{sub -51,310} GCs within a projected radius of 400 kpc. As many as half of the GCs may comprise an intracluster component. Even with the sizable uncertainties, which mainly result from the uncertain GCLF parameters, this system is by far the largest GC population studied to date. The specific frequency S{sub N} is high, but not uncommon for central galaxies in massive clusters, rising from S{sub N} ≈ 5 near the center to ∼12 at large radii. Passive galaxy fading would increase S{sub N} by ∼20% at z = 0. We construct the radial mass profiles of the GCs, stars, intracluster gas, and lensing-derived total mass, and we compare the mass fractions as a function of radius. The estimated mass in GCs, M{sub GC}{sup total} = 3.9 × 10{sup 10} M{sub ☉}, is comparable to ∼80% of the total stellar mass of the Milky Way. The shape of the GC mass profile appears intermediate between those of the stellar light and total cluster mass. Despite the extreme nature of this system, the ratios of the GC mass to the baryonic and total masses, and thus the GC formation efficiency, are typical of those in other rich clusters when comparing at the same physical radii. The GC formation efficiency is not constant, but varies with radius, in a manner that appears similar for different clusters; we speculate on the reasons for this similarity in profile.

  14. Quick Algorithms to Calculate Mean Time to Failure and Steady State Availability of Systems

    OpenAIRE

    Amiri Moslem; Přenosil Václav

    2012-01-01

    Calculation of reliability and availability is a necessary part of every fault tolerant system design. Conventional methods, which use calculus of probability, almost fail when there is dependant failure, repair, or standby operation in the system. Use of Markov models also almost breaks down when system is composed of many elements or system is repairable. However, the alternatives for reliability and availability, i.e., mean time to failure and steady state availability, respectively, are e...

  15. Cluster Based Cost Efficient Intrusion Detection System For Manet

    OpenAIRE

    Kumarasamy, Saravanan; B, Hemalatha; P, Hashini

    2013-01-01

    Mobile ad-hoc networks are temporary wireless networks. Network resources are abnormally consumed by intruders. Anomaly and signature based techniques are used for intrusion detection. Classification techniques are used in anomaly based techniques. Intrusion detection techniques are used for the network attack detection process. Two types of intrusion detection systems are available. They are anomaly detection and signature based detection model. The anomaly detection model uses the historica...

  16. The Rich Globular Cluster System of Abell 1689 and the Radial Dependence of the Globular Cluster Formation Efficiency

    CERN Document Server

    Alamo-Martínez, K A; Jee, M J; Côté, P; Ferrarese, L; González-Lópezlira, R A; Jordán, A; Meurer, G R; Peng, E W; West, M J

    2013-01-01

    We study the rich globular cluster (GC) system in the center of the massive cluster of galaxies Abell 1689 (z=0.18), one of the most powerful gravitational lenses known. With 28 HST/ACS orbits in the F814W bandpass, we reach magnitude I_814=29 with >90% completeness and sample the brightest ~5% of the GC system. Assuming the well-known Gaussian form of the GC luminosity function (GCLF), we estimate a total population of N(GC_total) = 162,850 GCs within a projected radius of 400kpc. As many as half may comprise an intracluster component. Even with the sizable uncertainties, which mainly result from the uncertain GCLF parameters, this is by far the largest GC system studied to date. The specific frequency S_N is high, but not uncommon for central galaxies in massive clusters, rising from S_N~5 near the center to ~12 at large radii. Passive galaxy fading would increase S_N by ~20% at z=0. We construct the radial mass profiles of the GCs, stars, intracluster gas, and lensing-derived total mass, and we compare the...

  17. Mapping differential reddening in the inner Galactic globular cluster system

    CERN Document Server

    Alonso-García, Javier; Sen, Bodhisattva; Banerjee, Moulinath; von Braun, Kaspar

    2011-01-01

    A serious limitation in the study of many globular clusters -- especially those located near the Galactic Center -- has been the existence of large and differential extinction by foreground dust. In a series of papers we intend to map the differential extinction and remove its effects, using a new dereddening technique, in a sample of clusters in the direction of the inner Galaxy, observed using the Magellan 6.5m telescope and the Hubble Space Telescope. These observations and their analysis will let us produce high quality color-magnitude diagrams of these poorly studied clusters that will allow us to determine these clusters' relative ages, distances and chemistry and to address important questions about the formation and the evolution of the inner Galaxy. We also intend to use the maps of the differential extinction to sample and characterize the interstellar medium along the numerous low latitude lines of sight where the clusters in our sample lie. In this first paper we describe in detail our dereddening...

  18. Performance Evaluation for Clustering Algorithms in Object-Oriented Database Systems

    CERN Document Server

    Darmont, Jérôme; Gourgand, Michel

    1995-01-01

    It is widely acknowledged that good object clustering is critical to the performance of object-oriented databases. However, object clustering always involves some kind of overhead for the system. The aim of this paper is to propose a modelling methodology in order to evaluate the performances of different clustering policies. This methodology has been used to compare the performances of three clustering algorithms found in the literature (Cactis, CK and ORION) that we considered representative of the current research in the field of object clustering. The actual performance evaluation was performed using simulation. Simulation experiments we performed showed that the Cactis algorithm is better than the ORION algorithm and that the CK algorithm totally outperforms both other algorithms in terms of response time and clustering overhead.

  19. 75 FR 76982 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2010-12-10

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... literature searches for IRIS assessments; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of literature searches for four IRIS...

  20. Hybrid Personalized Recommender System Using Modified Fuzzy C-Means Clustering Algorithm

    OpenAIRE

    Subhash K. Shinde, Uday V. kulkarni

    2010-01-01

    Recommender Systems apply machine learning and data mining techniques forfiltering unseen information and can predict whether a user would like a givenresource. This paper proposes a novel Modified Fuzzy C-means (MFCM)clustering algorithm which is used for Hybrid Personalized RecommenderSystem (MFCMHPRS). The proposed system works in two phases. In the firstphase, opinions from the users are collected in the form of user-item ratingmatrix. They are clustered offline using MFCM into predetermi...

  1. Phoenix Cloud: Consolidating Different Computing Loads on Shared Cluster System for Large Organization

    OpenAIRE

    Zhan, Jianfeng; Wang, Lei; Tu, Bibo; Li, Yong; WANG, PENG; Zhou, Wei; Meng, Dan

    2009-01-01

    Different departments of a large organization often run dedicated cluster systems for different computing loads, like HPC (high performance computing) jobs or Web service applications. In this paper, we have designed and implemented a cloud management system software Phoenix Cloud to consolidate heterogeneous workloads from different departments affiliated to the same organization on the shared cluster system. We have also proposed cooperative resource provisioning and management policies for...

  2. Hybrid Personalized Recommender System Using Modified Fuzzy C-Means Clustering Algorithm

    OpenAIRE

    Subhash K. Shinde; Uday V. Kulkarni

    2011-01-01

    Recommender Systems apply machine learning and data mining techniques for filtering unseen information and can predict whether a user would like a given resource. This paper proposes a novel Modified Fuzzy C-means (MFCM) clustering algorithm which is used for Hybrid Personalized Recommender System (MFCMHPRS). The proposed system works in two phases. In the first phase, opinions from the users are collected in the form of user-item rating matrix. They are clustered offline using MFCM into pred...

  3. Design Optimization of Multi-Cluster Embedded Systems for Real-Time Applications

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2006-01-01

    We present an approach to design optimization of multi-cluster embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. In this paper, we address design problems which are characteristic to multi-clusters: partitioning of the system functionality into...... time-triggered and event-triggered domains, process mapping, and the optimization of parameters corresponding to the communication protocol. We present several heuristics for solving these problems. Our heuristics are able to find schedulable implementations under limited resources, achieving an...... efficient utilization of the system. The developed algorithms are evaluated using extensive experiments and a real-life example....

  4. High-Performance, Multi-Node File Copies and Checksums for Clustered File Systems

    Science.gov (United States)

    Kolano, Paul Z.; Ciotti, Robert B.

    2012-01-01

    Modern parallel file systems achieve high performance using a variety of techniques, such as striping files across multiple disks to increase aggregate I/O bandwidth and spreading disks across multiple servers to increase aggregate interconnect bandwidth. To achieve peak performance from such systems, it is typically necessary to utilize multiple concurrent readers/writers from multiple systems to overcome various singlesystem limitations, such as number of processors and network bandwidth. The standard cp and md5sum tools of GNU coreutils found on every modern Unix/Linux system, however, utilize a single execution thread on a single CPU core of a single system, and hence cannot take full advantage of the increased performance of clustered file systems. Mcp and msum are drop-in replacements for the standard cp and md5sum programs that utilize multiple types of parallelism and other optimizations to achieve maximum copy and checksum performance on clustered file systems. Multi-threading is used to ensure that nodes are kept as busy as possible. Read/write parallelism allows individual operations of a single copy to be overlapped using asynchronous I/O. Multinode cooperation allows different nodes to take part in the same copy/checksum. Split-file processing allows multiple threads to operate concurrently on the same file. Finally, hash trees allow inherently serial checksums to be performed in parallel. Mcp and msum provide significant performance improvements over standard cp and md5sum using multiple types of parallelism and other optimizations. The total speed-ups from all improvements are significant. Mcp improves cp performance over 27x, msum improves md5sum performance almost 19x, and the combination of mcp and msum improves verified copies via cp and md5sum by almost 22x. These improvements come in the form of drop-in replacements for cp and md5sum, so are easily used and are available for download as open source software at http://mutil.sourceforge.net.

  5. Smart System to Recognize EEG Signal for Finding Brain Diseases Using K-Means Clustering

    Directory of Open Access Journals (Sweden)

    K.Gomathi

    2013-12-01

    Full Text Available In this paper, we are providing a research ideology, in which analysis of the EEG signal is done using an intelligent system in order to detect the brain diseases such as Epilepsy, Alzheimer’s disease etc. Here we are supposed to use clustering algorithm called k-means for distinguishing various diseases of human brain. Our main aim is to help the doctors by reducing the time complexity in analyzing EEG signal by our detection system which produces better results. We are proposing a technique of detecting epilepsy disorder and Alzheimer disease using k-means algorithm using MATLAB. The back propagation algorithm is also used in the classification network and discrete wavelet transform are used to process the EEG signal. Automated analyses of neurological disorders like Epilepsy, Alzheimer’s disease are being discussed.

  6. Cluster algorithms with empahsis on quantum spin systems

    International Nuclear Information System (INIS)

    The purpose of this lecture is to discuss in detail the generalized approach of Kawashima and Gubernatis for the construction of cluster algorithms. We first present a brief refresher on the Monte Carlo method, describe the Swendsen-Wang algorithm, show how this algorithm follows from the Fortuin-Kastelyn transformation, and re=interpret this transformation in a form which is the basis of the generalized approach. We then derive the essential equations of the generalized approach. This derivation is remarkably simple if done from the viewpoint of probability theory, and the essential assumptions will be clearly stated. These assumptions are implicit in all useful cluster algorithms of which we are aware. They lead to a quite different perspective on cluster algorithms than found in the seminal works and in Ising model applications. Next, we illustrate how the generalized approach leads to a cluster algorithm for world-line quantum Monte Carlo simulations of Heisenberg models with S = 1/2. More succinctly, we also discuss the generalization of the Fortuin- Kasetelyn transformation to higher spin models and illustrate the essential steps for a S = 1 Heisenberg model. Finally, we summarize how to go beyond S = 1 to a general spin, XYZ model

  7. Globular cluster system and Milky Way properties revisited

    CERN Document Server

    Bica, E; Barbuy, B; Ortolani, S; Bica, Eduardo; Bonatto, Charles; Barbuy, Beatriz; Ortolani, Sergio

    2005-01-01

    Updated data of the 153 Galactic globular clusters are used to readdress fundamental parameters of the Milky Way. We build a reduced sample, decontaminated of the clusters younger than 10Gyr, those with retrograde orbits and/or evidence of relation to dwarf galaxies. The 33 metal-rich globular clusters of the reduced sample extend basically to the Solar circle and distribute over a region with projected axial-ratios typical of an oblate spheroidal, $\\rm\\Delta x:\\Delta y:\\Delta z\\approx1.0:0.9:0.4$. The 81 metal-poor globular clusters span a nearly spherical region of axial-ratios $\\approx1.0:1.0:0.8$ extending from the central parts to the outer halo. A new estimate of the Sun's distance to the Galactic center is provided, $\\rm R_O=7.2\\pm0.3 kpc$. The metal-rich and metal-poor radial-density distributions flatten for $\\rm R_{GC}\\leq2 kpc$ and are well represented both by a power-law with a core-like term and S\\'ersic's law; at large distances they fall off as $\\rm\\sim R^{-3.9}$. Both metallicity components ap...

  8. Single system image: pilar de los sistemas de clustering

    OpenAIRE

    Echaiz, Javier; Ardenghi, Jorge Raúl

    2003-01-01

    El objetivo principal de este trabajo es comparar diferentes sistemas operativos distribuidos. En especial se busca comparar las distintas alternativas, ventajas y potenciales de SSI implementado en los distintos niveles de un sistema con soporte para clustering. Los resultados de este análisis brindarán el marco necesario para futuras investigaciones y desarrollos en este campo.

  9. Dynamics of the NGC 4636 globular cluster system II. Improved constraints from a large sample of globular cluster velocities

    CERN Document Server

    Schuberth, Ylva; Hilker, Michael; Salinas, Ricardo; Dirsch, Boris; Larsen, Soeren S

    2012-01-01

    We present new radial velocities for 289 globular clusters around NGC 4636, the southernmost giant elliptical galaxy of the Virgo cluster. The data were obtained with FORS2/MXU at the Very Large Telescope. Together with data analysed in an earlier study (Schuberth et al. 2006), we now have a sample of 460 globular cluster velocities out to a radius of 12 arcmin (60 kpc) available - one of the largest of its kind. This new data set also provides a much more complete angular coverage. Moreover, we present new kinematical data of the inner stellar population of NGC 4636. We perform an updated Jeans analysis, using both stellar and GC data, to better constrain the dark halo properties. We find a stellar M/L-ratio of 5.8 in the R-band, higher than expected from single stellar population synthesis. We model the dark halo by cored and cuspy analytical halo profiles and consider different anisotropies for the tracer populations. Properties of NFW halos lie well within the expected range of cosmological simulations. C...

  10. Availability analysis of thermal power plant boiler air circulation system using Markov approach

    Directory of Open Access Journals (Sweden)

    Ravinder Kumar

    2014-01-01

    Full Text Available The long term operation and planning of power plant depend upon an effective availability analysis and assessment of various systems in the plant concerned. The plant is expected to remain operational in a continual manner to achieve the desired production targets. Hence, the availability analysis of the boiler air circulation system plays an important role in this direction. For this purpose, the concerned system mathematical model based on Markov Birth-Death process has been developed. The system consists of four subsystems. The transition diagram represents reduced capacity, full working and failed state of the system. The differential equations associated with the transition diagram based on probabilistic approach have been solved recursively in order to develop the system steady state availability. Availability matrices represented measures the performance of the system concerned. In addition, different combinations of failures and repair rates provide various availability levels of the system. Maintenance decisions are taken based upon these values for improving availability of the power plant as well as the power supply. The result shows that the failure of the primary air fan affects the system availability at most, while failure of air heater affect it at least for different failures and repair rate combination of subsystems under study.

  11. Availability estimation of repairable systems using reliability graph with general gates (RGGG)

    International Nuclear Information System (INIS)

    By performing risk analysis, we may obtain sufficient information about the system to redesign it and lower the probability of the occurrence of an accident or mitigate the ensuing consequences. The concept of reliability is widely used to express risk of systems. The reliability is used for non-repairable systems. But nuclear power plant systems are repairable systems. With repairable systems, repairable components can improve the availability of a system because faults that are generated in components can be recovered. Hence, the availability of the system is more proper concept in case of repairable systems. Reliability graph with general gate (RGGG) is one of the system reliability analysis methods. The RGGG is a very intuitiveness method as compared with other methods. But the RGGG has not been applied to repairable systems yet. The objective of this study is to extend the RGGG in order to enable one to analyze repairable system. Determining the probability table for each node is a critical process to calculate the system availability in the RGGG method. Therefore finding the proper algorithms and making probability tables in various situations are the major a part of this study. The other part is an example of applying RGGG method to a real system. We find the proper algorithms and probability tables for independent repairable systems, dependent series repairable systems, and k-out-of-m (K/M) redundant parallel repairable systems in this study. We can evaluate the availability of real system using these probability tables. An example for a real system is shown in the latter part of this study. For the purpose of this analysis, the charging pumps subsystem of the chemical and volume control system (CVCS) was selected. The RGGG method extended for repairable systems has the same characteristic of intuitiveness as the original RGGG method and we can confirm that the availability analysis result from the repairable RGGG method is exact

  12. Availability estimation of repairable systems using reliability graph with general gates (RGGG)

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Gyoung Tae

    2009-02-15

    By performing risk analysis, we may obtain sufficient information about the system to redesign it and lower the probability of the occurrence of an accident or mitigate the ensuing consequences. The concept of reliability is widely used to express risk of systems. The reliability is used for non-repairable systems. But nuclear power plant systems are repairable systems. With repairable systems, repairable components can improve the availability of a system because faults that are generated in components can be recovered. Hence, the availability of the system is more proper concept in case of repairable systems. Reliability graph with general gate (RGGG) is one of the system reliability analysis methods. The RGGG is a very intuitiveness method as compared with other methods. But the RGGG has not been applied to repairable systems yet. The objective of this study is to extend the RGGG in order to enable one to analyze repairable system. Determining the probability table for each node is a critical process to calculate the system availability in the RGGG method. Therefore finding the proper algorithms and making probability tables in various situations are the major a part of this study. The other part is an example of applying RGGG method to a real system. We find the proper algorithms and probability tables for independent repairable systems, dependent series repairable systems, and k-out-of-m (K/M) redundant parallel repairable systems in this study. We can evaluate the availability of real system using these probability tables. An example for a real system is shown in the latter part of this study. For the purpose of this analysis, the charging pumps subsystem of the chemical and volume control system (CVCS) was selected. The RGGG method extended for repairable systems has the same characteristic of intuitiveness as the original RGGG method and we can confirm that the availability analysis result from the repairable RGGG method is exact.

  13. Properties of young star cluster systems: the age signature from near-infrared integrated colours

    CERN Document Server

    Santos, J F C; Grosbøl, P

    2013-01-01

    A recent JHKs study of several grand-design spiral galaxies shows a bimodal distribution of their system of star clusters and star forming complexes in colour-magnitude and colour-colour diagrams. In a comparison with stellar population models including gas, the (J-H) vs (H-Ks) diagram reveals that embedded clusters, still immersed in their parental clouds of gas and dust, generally have a redder (H-Ks) colour than older clusters, whose gas and dust have already been ejected. This bimodal behaviour is also evident in the colour-magnitude diagram MK vs (J-Ks), where the brightest clusters split into two sequences separating younger from older clusters. In addition, the reddening-free index Qd = (H-Ks) - 0.884 (J-H) has been shown to correlate with age for the young clusters and thus provided an effective way to differentiate the embedded clusters from the older ones. We aim to study the behaviour of these photometric indices for star cluster systems in the Local Group. We investigate the effectiveness of the Q...

  14. A Catalog of Globular Cluster Systems: What Determines the Size of a Galaxy's Globular Cluster Population?

    CERN Document Server

    Harris, William E; Alessi, Matthew

    2013-01-01

    We present a catalog of 422 galaxies with published measurements of their globular cluster (GC) populations. Of these, 248 are E galaxies, 93 are S0 galaxies, and 81 are spirals or irregulars. Among various correlations of the total number of GCs with other global galaxy properties, we find that N_GC correlates well though nonlinearly with the dynamical mass of the galaxy bulge M_dyn = 4 \\sigma_e^2 R_e /G, where \\sigma_e is the central velocity dispersion and R_e the effective radius of the galaxy light profile. We also present updated versions of the GC specific frequency S_N and specific mass S_M versus host galaxy luminosity and baryonic mass. These graphs exhibit the previously known U-shape: highest S_N or S_M values occur for either dwarfs or supergiants, but in the midrange of galaxy size (10^9 - 10^10 L_Sun) the GC numbers fall along a well defined baseline value of S_N ~ 1 or S_M ~ 0.1, similar among all galaxy types. Along with other recent discussions, we suggest that this trend may represent the e...

  15. Hydrogen spillover on DV (555-777) graphene – vanadium cluster system: First principles study

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, E. Mathan, E-mail: ranjit.t@res.srmuniv.ac.in, E-mail: mathanranjitha@gmail.com; Thapa, Ranjit, E-mail: ranjit.t@res.srmuniv.ac.in, E-mail: mathanranjitha@gmail.com [SRM Research Institute, SRM University, Kattankulathur, Tamil Nadu - 603203 (India); P, Sabarikirishwaran [Department of Physics and Nanotechnology, SRM University, Kattankulathur, Tamil Nadu - 603203 (India)

    2015-06-24

    Using dispersion corrected density functional theory (DFT+D), the interaction of Vanadium adatom and cluster with divacancy (555-777) defective graphene sheet has been studied elaborately. We explore the prospect of hydrogen storage on V{sub 4} cluster adsorbed divacancy graphene system. It has been observed that V{sub 4} cluster (acting as a catalyst) can dissociate the H{sub 2} molecule into H atoms with very low barrier energy. We introduce the spillover of the atomic hydrogen throughout the surface via external mediator gallane (GaH{sub 3}) to form a hydrogenated system.

  16. Hydrogen spillover on DV (555-777) graphene – vanadium cluster system: First principles study

    International Nuclear Information System (INIS)

    Using dispersion corrected density functional theory (DFT+D), the interaction of Vanadium adatom and cluster with divacancy (555-777) defective graphene sheet has been studied elaborately. We explore the prospect of hydrogen storage on V4 cluster adsorbed divacancy graphene system. It has been observed that V4 cluster (acting as a catalyst) can dissociate the H2 molecule into H atoms with very low barrier energy. We introduce the spillover of the atomic hydrogen throughout the surface via external mediator gallane (GaH3) to form a hydrogenated system

  17. Schedulability Analysis and Optimization for the Synthesis of Multi-Cluster Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2003-01-01

    We present an approach to schedulability analysis for the synthesis of multi-cluster distributed embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. We have also proposed a buffer size and worst case queuing delay analysis for the gateways......, responsible for routing inter-cluster traffic. Optimization heuristics for the priority assignment and synthesis of bus access parameters aimed at producing a schedulable system with minimal buffer needs have been proposed. Extensive experiments and a real-life example show the efficiency of our approaches....

  18. Schedulability Analysis and Optimization for the Synthesis of Multi-Cluster Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2003-01-01

    An approach to schedulability analysis for the synthesis of multi-cluster distributed embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways, is presented. A buffer size and worst case queuing delay analysis for the gateways, responsible for routing...... inter-cluster traffic, is also proposed. Optimisation heuristics for the priority assignment and synthesis of bus access parameters aimed at producing a schedulable system with minimal buffer needs have been proposed. Extensive experiments and a real-life example show the efficiency of the approaches....

  19. The quantization of the radii of coordination spheres cubic crystals and cluster systems

    Science.gov (United States)

    Melnikov, G.; Emelyanov, S.; Ignatenko, N.; Ignatenko, G.

    2016-02-01

    The article deals with the creation of an algorithm for calculating the radii of coordination spheres and coordination numbers cubic crystal structure and cluster systems in liquids. Solution has important theoretical value since it allows us to calculate the amount of coordination in the interparticle interaction potentials, to predict the processes of growth of the crystal structures and processes of self-organization of particles in the cluster system. One option accounting geometrical and quantum factors is the use of the Fibonacci series to construct a consistent number of focal areas for cubic crystals and cluster formation in the liquid.

  20. Clustering of resting state networks.

    Directory of Open Access Journals (Sweden)

    Megan H Lee

    Full Text Available BACKGROUND: The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm. METHODOLOGY/PRINCIPAL FINDINGS: The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization. CONCLUSIONS/SIGNIFICANCE: The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

  1. System Availability in the Presence of Estimating Common-cause Time-varying Failure Rates

    Directory of Open Access Journals (Sweden)

    M. A. El-Damcese

    2005-01-01

    Full Text Available This study presents a method for calculating the availability of a system depicted by availability block diagram, with identically distributed components, in the presence of estimating common cause hazard, we use the Marshall and Olkin formulation of the multivariate exponential distribution. That is, the components are subject to failure by Poisson failure processes that govern simultaneous failure of a specific subset of the components. A model is proposed for the analysis of systems subject to common-cause failures that are not considered to have a constant rate but that are assumed to obey a uniqueness of maximum likelihood estimators of the 2-parameter Weibull distribution. The method for calculating the system availability requires that a procedure exists for determining the system availability from component availabilities, under the statistically independent component assumption. The study includes an example to illustrate the method.

  2. Reliability, reliability with repair, and availability of four identical element multiplex systems

    International Nuclear Information System (INIS)

    Reliability, reliability with repair, and availability concepts for specific configurations of four identical element systems, including series, parallel, and multiplex systems, are developed using a continuous time Markov process. As the number of systems components increases, the Markov approach leads to complex sets of differential equations that require computer solution. The multiplex system availability, reliability with repair, and reliability are superior to that of both the parallel and series systems. Multiplexing offers the opportunity for reliability improvement in the design of nuclear safety systems

  3. Metallicity distributions of globular cluster systems in galaxies

    OpenAIRE

    Eerik, Helina; Tenjes, Peeter

    2002-01-01

    We collected a sample of 100 galaxies for which different observers have determined colour indices of globular cluster candidates. The sample includes representatives of galaxies of various morphological types and different luminosities. Colour indices (in most cases (V-I), but also (B-I) and (C-T1)) were transformed into metallicities [Fe/H] according to a relation by Kissler-Patig (1998). These data were analysed with the KMM software in order to estimate similarity of the distribution with...

  4. Interference Mitigation Techniques for Clustered Multicell Joint Decoding Systems

    OpenAIRE

    Chatzinotas Symeon; Ottersten Björn

    2011-01-01

    Abstract Multicell joint processing has originated from information-theoretic principles as a means of reaching the fundamental capacity limits of cellular networks. However, global multicell joint decoding is highly complex and in practice clusters of cooperating Base Stations constitute a more realistic scenario. In this direction, the mitigation of intercluster interference rises as a critical factor towards achieving the promised throughput gains. In this paper, two intercluster interfere...

  5. Photoinduced Processes in Hydrogen Bonded System: Photodissociation of Imidazole Clusters

    Czech Academy of Sciences Publication Activity Database

    Poterya, Viktoriya; Profant, V.; Fárník, Michal; Šištík, L.; Slavíček, P.; Buck, U.

    2009-01-01

    Roč. 113, č. 52 (2009), s. 14583-14590. ISSN 1089-5639 R&D Projects: GA AV ČR KAN400400651; GA AV ČR KJB400400902; GA ČR GA203/09/0422 Institutional research plan: CEZ:AV0Z40400503 Keywords : scattering analysis * molecules * imidazole clusters Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.899, year: 2009

  6. Special resonances in two- and three-cluster systems

    International Nuclear Information System (INIS)

    In the framework of Schmid's N-cluster theory the resonance theory of Wildermuth-Benoehr is extended to three clusters. This three-cluster resonance model is solved in a mathematically exact formalism. The main topic of this formalism is the asymptotic behaviour of the full three-body-resolvent in the differential directions of the six-dimensional position space of the Jacobi coordinates. The scattering amplitudes and cross sections in all two-body channels and breakup are explicitly presented. Furthermore a very illustrative kinematical three-body model, the so called 'three-body-neb', is developed. Special regards in this connection are devoted to the analysis of possible interference possibilities of the main three-body-resonance with other resonance types of the three-body model. In a further section the Pauli-resonances are studied i) in the Wildermuth resonating group theory, ii) in Schmid's simulation models. It is shown under which circumstances Pauli-resonances may be positive energy bound states. (orig./HSI)

  7. Telecardiology and Teletreatment System Design for Heart Failures Using Type-2 Fuzzy Clustering Neural Networks

    Directory of Open Access Journals (Sweden)

    Rahime Ceylan

    2011-02-01

    Full Text Available Proper diagnosis of heart failures is critical, since the appropriate treatments are strongly dependent upon the underlying cause. Furthermore, rapid diagnosis is also critical, since the effectiveness of some treatments depends upon rapid initiation. In this paper, a new web-based telecardiology system has been proposed for diagnosis, consultation, and treatment. The aim of this implemented telecardiology system is to help to practitioner doctor, if clinic findings of patient misgive heart failures. This model consists of three subsystems. The first subsystem divides into recording and preprocessing phase. Here, electrocardiography signal is recorded from emergency patient and this recorded signal is preprocessed for detection of RR interval. The second subsystem realizes classification of RR interval. In other words, this second subsystem is to diagnosis heart failures. In this study, a combined classification system has been designed using type-2 fuzzy c-means clustering (T2FCM algorithm and neural networks. T2FCM was used to improve performance of neural networks which was obtained very high performance accuracy to classify RR intervals of ECG signals. This proposed automated telecardiology and diagnostic system assists to practitioner doctor to diagnosis heart failures easily. Training and testing data for this diagnostic system are included five ECG signal classes. The third subsystem is consultation and teletreatment between practitioner (or family doctor and cardiologist worked in research hospital with prepared web page (www.telekardiyoloji.com. However, opportunity of signal’s evaluation is presented to practitioner and expert doctor with prepared interfaces. T2FCM is applied to the training data for the selection of best segments in the second subsystem. A new training set formed by these best segments was classified using the neural networks classifier which has backpropagation well-known algorithm and generalized delta rule

  8. Inspection-Repair based Availability Optimization of Distribution Systems using Teaching Learning based Optimization

    Science.gov (United States)

    Tiwary, Aditya; Arya, L. D.; Arya, Rajesh; Choube, S. C.

    2015-03-01

    This paper describes a technique for optimizing inspection and repair based availability of distribution systems. Optimum duration between two inspections has been obtained for each feeder section with respect to cost function and subject to satisfaction of availability at each load point. Teaching learning based optimization has been used for availability optimization. The developed algorithm has been implemented on radial and meshed distribution systems. The result obtained has been compared with those obtained with differential evolution.

  9. A Comprehensive Availability Modeling and Analysis of a Virtualized Servers System Using Stochastic Reward Nets

    OpenAIRE

    Tuan Anh Nguyen; Dong Seong Kim; Jong Sou Park

    2014-01-01

    It is important to assess availability of virtualized systems in IT business infrastructures. Previous work on availability modeling and analysis of the virtualized systems used a simplified configuration and assumption in which only one virtual machine (VM) runs on a virtual machine monitor (VMM) hosted on a physical server. In this paper, we show a comprehensive availability model using stochastic reward nets (SRN). The model takes into account (i) the detailed failures and recovery behavio...

  10. Fuzzy Availability Assessment for a Repairable Multistate Series-Parallel System

    Directory of Open Access Journals (Sweden)

    Linmin Hu

    2015-01-01

    Full Text Available This paper considers a repairable multistate series-parallel system (RMSSPS with fuzzy parameters. It is assumed that the system components are independent, and their state transition rates and performance rates are fuzzy values. The fuzzy universal generating function technique is adopted to determine fuzzy state probability and fuzzy performance rate of the system. On the basis of α-cut approach and the extension principle, parametric programming technique is employed to obtain the α-cuts of some indices for the system. The system fuzzy availability is defined as the ability of the system to satisfy fuzzy consumer demand. A special assessment approach is developed for evaluating the fuzzy steady-state availability of the system with the fuzzy demand. A flow transmission system with three components is presented to demonstrate the validity of the proposed method.

  11. The Astronomy of Africa's Health Systems Literature During the MDG Era: Where Are the Systems Clusters?

    Science.gov (United States)

    Phillips, James F; Sheff, Mallory; Boyer, Christopher B

    2015-09-01

    Growing international concern about the need for improved health systems in Africa has catalyzed an expansion of the health systems literature. This review applies a bibliometric procedure to analyze the acceleration of scientific writing on this theme. We focus on research published during the Millennium Development Goal (MDG) era between 1990 and 2014, reporting findings from a systematic review of a database comprised of 17,655 articles about health systems themes from sub-Saharan African countries or subregions. Using bibliometric tools for co-word textual analysis, we analyzed the incidence and associations of keywords and phrases to generate and visualize topical foci on health systems as clusters of themes, much in the manner that astronomers represent groupings of stars as galaxies of celestial entities. The association of keywords defines their relative position, with the size of images weighted by the relative frequency of terms. Sets of associated keywords are arrayed as stars that cluster as "galaxies" of concepts in the knowledge universe represented by health systems research from sub-Saharan Africa. Results show that health systems research is dominated by literature on diseases and categorical systems research topics, rather than on systems science that cuts across diseases or specific systemic themes. Systems research is highly developed in South Africa but relatively uncommon elsewhere in the region. "Black holes" are identified by searching for terms in our keyword library related to terms in widely cited reviews of health systems. Results identify several themes that are unexpectedly uncommon in the country-specific health systems literature. This includes research on the processes of achieving systems change, the health impact of systems strengthening, processes that explain the systems determinants of health outcomes, or systematic study of organizational dysfunction and ways to improve system performance. Research quantifying the relationship

  12. Algorithm for break even availability allocation in process system modification using deterministic valuation model incorporating reliability

    International Nuclear Information System (INIS)

    In the present scenario of energy demand overtaking energy supply, top priority is given for energy conservation programs and policies. As a result, most existing systems are redesigned or modified with a view for improving energy efficiency. Often these modifications can have an impact on process system configuration, thereby affecting process system reliability. The paper presents a model for valuation of process systems incorporating reliability that can be used to determine the change in process system value resulting from system modification. The model also determines the break even system availability and presents an algorithm for allocation of component reliabilities of the modified system based on the break even system availability. The developed equations are applied to a steam power plant to study the effect of various operating parameters on system value

  13. A CATALOG OF GLOBULAR CLUSTER SYSTEMS: WHAT DETERMINES THE SIZE OF A GALAXY'S GLOBULAR CLUSTER POPULATION?

    International Nuclear Information System (INIS)

    We present a catalog of 422 galaxies with published measurements of their globular cluster (GC) populations. Of these, 248 are E galaxies, 93 are S0 galaxies, and 81 are spirals or irregulars. Among various correlations of the total number of GCs with other global galaxy properties, we find that NGC correlates well though nonlinearly with the dynamical mass of the galaxy bulge Mdyn= 4σe2 Re /G, where σe is the central velocity dispersion and Re the effective radius of the galaxy light profile. We also present updated versions of the GC specific frequency SN and specific mass SM versus host galaxy luminosity and baryonic mass. These graphs exhibit the previously known U-shape: highest SN or SM values occur for either dwarfs or supergiants, but in the midrange of galaxy size (109-1010 L☉) the GC numbers fall along a well-defined baseline value of SN ≅ 1 or SM = 0.1, similar among all galaxy types. Along with other recent discussions, we suggest that this trend may represent the effects of feedback, which systematically inhibited early star formation at either very low or very high galaxy mass, but which had its minimum effect for intermediate masses. Our results strongly reinforce recent proposals that GC formation efficiency appears to be most nearly proportional to the galaxy halo mass Mhalo. The mean 'absolute' efficiency ratio for GC formation that we derive from the catalog data is MGCS/Mhalo = 6 × 10–5. We suggest that the galaxy-to-galaxy scatter around this mean value may arise in part because of differences in the relative timing of GC formation versus field-star formation. Finally, we find that an excellent empirical predictor of total GC population for galaxies of all luminosities is NGC ∼ (Re σe)1.3, a result consistent with fundamental plane scaling relations

  14. An Extended Membrane System with Active Membranes to Solve Automatic Fuzzy Clustering Problems.

    Science.gov (United States)

    Peng, Hong; Wang, Jun; Shi, Peng; Pérez-Jiménez, Mario J; Riscos-Núñez, Agustín

    2016-05-01

    This paper focuses on automatic fuzzy clustering problem and proposes a novel automatic fuzzy clustering method that employs an extended membrane system with active membranes that has been designed as its computing framework. The extended membrane system has a dynamic membrane structure; since membranes can evolve, it is particularly suitable for processing the automatic fuzzy clustering problem. A modification of a differential evolution (DE) mechanism was developed as evolution rules for objects according to membrane structure and object communication mechanisms. Under the control of both the object's evolution-communication mechanism and the membrane evolution mechanism, the extended membrane system can effectively determine the most appropriate number of clusters as well as the corresponding optimal cluster centers. The proposed method was evaluated over 13 benchmark problems and was compared with four state-of-the-art automatic clustering methods, two recently developed clustering methods and six classification techniques. The comparison results demonstrate the superiority of the proposed method in terms of effectiveness and robustness. PMID:26790484

  15. 高可用CORBA%The Design and Realization of Highly Availability Distributed System of CORBA

    Institute of Scientific and Technical Information of China (English)

    郭乐深; 刘锦德

    2000-01-01

    Recently,while highly available computer systems used for homogeneous environment have been launched into market,those used for heterogeneous environment are still staying vendors' research labs. In this paper,a highly availability distributed system based on CORBA is proposed,and the design and implementation of this system are fully explained. The analysis results show that the scheme presented is an effective approach.

  16. Availability analysis of thermal power plant boiler air circulation system using Markov approach

    OpenAIRE

    Ravinder Kumar

    2014-01-01

    The long term operation and planning of power plant depend upon an effective availability analysis and assessment of various systems in the plant concerned. The plant is expected to remain operational in a continual manner to achieve the desired production targets. Hence, the availability analysis of the boiler air circulation system plays an important role in this direction. For this purpose, the concerned system mathematical model based on Markov Birth-Death process has been developed. The ...

  17. AVAILABILITY ANALYSIS OF THE QUEUEING SYSTEM GI/PH/1 WITH SERVER BREAKDOWNS

    Institute of Scientific and Technical Information of China (English)

    YUAN Xueming; LI Wei

    2003-01-01

    In the existing literature of Repairable Queueing Systems (RQS), i.e., queueing systems with server breakdowns, it is almost all assumed that interarrival times of successive customers are independent, identically exponentially distributed. In this paper, we deal with more generic system GI/PH/1 with server's exponential uptime and phase-type repair time. With matrix analysis theory, we establish the equilibrium condition and the characteristics of the system, derive the transient and stationary availability behavior of the system.

  18. An interactive visual testbed system for dimension reduction and clustering of large-scale high-dimensional data

    Science.gov (United States)

    Choo, Jaegul; Lee, Hanseung; Liu, Zhicheng; Stasko, John; Park, Haesun

    2013-01-01

    Many of the modern data sets such as text and image data can be represented in high-dimensional vector spaces and have benefited from computational methods that utilize advanced computational methods. Visual analytics approaches have contributed greatly to data understanding and analysis due to their capability of leveraging humans' ability for quick visual perception. However, visual analytics targeting large-scale data such as text and image data has been challenging due to the limited screen space in terms of both the numbers of data points and features to represent. Among various computational methods supporting visual analytics, dimension reduction and clustering have played essential roles by reducing these numbers in an intelligent way to visually manageable sizes. Given numerous dimension reduction and clustering methods available, however, the decision on the choice of algorithms and their parameters becomes difficult. In this paper, we present an interactive visual testbed system for dimension reduction and clustering in a large-scale high-dimensional data analysis. The testbed system enables users to apply various dimension reduction and clustering methods with different settings, visually compare the results from different algorithmic methods to obtain rich knowledge for the data and tasks at hand, and eventually choose the most appropriate path for a collection of algorithms and parameters. Using various data sets such as documents, images, and others that are already encoded in vectors, we demonstrate how the testbed system can support these tasks.

  19. The use of a VAX cluster for the DIII-D data acquisition system

    International Nuclear Information System (INIS)

    The DIII-D tokamak is a large fusion energy research experiment funded by the Department of Energy. The experiment currently collects nearly 40 Mbytes of data from each shot of the experiment. In the past, most of this data was acquired through the MODCOMP Classic data acquisition computers and then transferred to a DEC VAX computer system for permanent archiving and storage. A much smaller amount of data was acquired from a few MicroVAX based data acquisition systems. In the last two years, MicroVAX based systems have become the standard means for adding new diagnostic data and account for half the total data. There are now 17 VAX systems of various types at the DIII-D facility. As more diagnostics and data are added, it takes increasing of time to merge the data into the central shot file. The system management of so many systems has become increasingly time consuming as well. To improve the efficiency of the overall data acquisition system, a mixed interconnect VAX cluster has been formed consisting of 16 VAX computers. In the cluster, the software protocol for passing data around the cluster is much more efficient than using DECnet. The cluster has also greatly simplified the procedure of backing up disks. Another big improvement is the use of a VAX console system which ties all the console ports of the computers into one central computer system which then manages the entire cluster

  20. Visualizing the software system towards identifying the topic from source code using semantic clustering

    Directory of Open Access Journals (Sweden)

    Kanchan Sharma

    2014-03-01

    Full Text Available In software re-engineering, domain knowledge are valuable source of information for developers. Here, we describe how the coding standards are helpful for the identification of domain while writing the source code. Internal comments and logical identifier names in source code are the key source to find the concept and domain area for the application. One of the Information retrieval techniques, Latent Semantic Indexing (LSI uses this linguistic information such as identifier names and comments in source code to map it with the domain name. Based on the linguistic results from LSI engine, a clustering technique used to group source artifacts that use similar vocabulary and a way of representing complex system into simpler components. It works at the source code textual level and making it language independent. Prior research activity correlated the semantics with structural information and applied it at different level of abstraction. Based on the frequency of the domain terms labeling has been provided after discrete characterization of the clusters, using machine learning and visually explored. Visualization makes the concept detection much easier.

  1. A Survey On: Content Based Image Retrieval Systems Using Clustering Techniques For Large Data sets

    Directory of Open Access Journals (Sweden)

    Monika Jain

    2011-12-01

    Full Text Available Content-based image retrieval (CBIR is a new but widely adopted method for finding images from vastand unannotated image databases. As the network and development of multimedia technologies arebecoming more popular, users are not satisfied with the traditional information retrieval techniques. Sonowadays the content based image retrieval (CBIR are becoming a source of exact and fast retrieval. Inrecent years, a variety of techniques have been developed to improve the performance of CBIR. Dataclustering is an unsupervised method for extraction hidden pattern from huge data sets. With large datasets, there is possibility of high dimensionality. Having both accuracy and efficiency for high dimensionaldata sets with enormous number of samples is a challenging arena. In this paper the clustering techniquesare discussed and analysed. Also, we propose a method HDK that uses more than one clustering techniqueto improve the performance of CBIR.This method makes use of hierachical and divide and conquer KMeansclustering technique with equivalency and compatible relation concepts to improve the performanceof the K-Means for using in high dimensional datasets. It also introduced the feature like color, texture andshape for accurate and effective retrieval system.

  2. Telecardiology and Teletreatment System Design for Heart Failures Using Type-2 Fuzzy Clustering Neural Networks

    Directory of Open Access Journals (Sweden)

    Rahime Ceylan , Yüksel Özbay & Bekir Karlik

    2010-12-01

    Full Text Available Proper diagnosis of heart failures is critical, since the appropriate treatments arestrongly dependent upon the underlying cause. Furthermore, rapid diagnosis is alsocritical, since the effectiveness of some treatments depends upon rapid initiation. In thispaper, a new web-based telecardiology system has been proposed for diagnosis,consultation, and treatment. The aim of this implemented telecardiology system is tohelp to practitioner doctor, if clinic findings of patient misgive heart failures. This modelconsists of three subsystems. The first subsystem divides into recording andpreprocessing phase. Here, electrocardiography signal is recorded from emergencypatient and this recorded signal is preprocessed for detection of RR interval. Thesecond subsystem realizes classification of RR interval. In other words, this secondsubsystem is used to diagnosis heart failures. In this study, a combined classificationsystem has been designed using type-2 fuzzy c-means clustering (T2FCM algorithmand neural networks. T2FCM was used to improve performance of neural networkswhich was obtained very high performance accuracy to classify RR intervals of ECGsignals. This proposed automated telecardiology and diagnostic system assists topractitioner doctor to diagnosis heart failures easily. Training and testing data for thisdiagnostic system include five ECG signal classes. The third subsystem is consultationand teletreatment between practitioner (or family doctor and cardiologist worked inresearch hospital with prepared web page (www.telekardiyoloji.com. However,opportunity of signal’s evaluation is presented to practitioner and expert doctor withprepared interfaces. T2FCM is applied to the training data for the selection of bestsegments in the second subsystem. A new training set formed by these best segmentswas classified using the neural networks classifier which has well-knownbackpropagation algorithm and generalized delta rule learning. Correct

  3. Job Oriented Monitoring Clusters

    Directory of Open Access Journals (Sweden)

    Vijayalaxmi Cigala,

    2011-03-01

    Full Text Available There has been a lot of development in the field of clusters and grids. Recently, the use of clusters has been on rise in every possible field. This paper proposes a system that monitors jobs onlarge computational clusters. Monitoring jobs is essential to understand how jobs are being executed. This helps us in understanding the complete life cycle of the jobs being executed on large clusters. Also, this paper describes how the information obtained by monitoring the jobs would help in increasing the overall throughput of clusters. Heuristics help in efficient job distribution among the computational nodes, thereby accomplishing fair job distribution policy. The proposed system would be capable of loadbalancing among the computational nodes, detecting failures, taking corrective actions after failure detection, job monitoring, system resource monitoring, etc.

  4. The SLUGGS Survey: Wide Field Imaging of the Globular Cluster System of NGC 4278

    CERN Document Server

    Usher, Christopher; Spitler, Lee R; Brodie, Jean P; Romanowsky, Aaron J; Strader, Jay; Woodley, Kristin A

    2013-01-01

    We use multi-pointing HST ACS and wide field Subaru Suprime-Cam imaging to study the globular cluster system of the L* elliptical galaxy NGC 4278. We have also obtained a handful of new globular cluster spectra with Keck/DEIMOS. We determine the globular cluster surface density profile and use it to calculate the total number of globular clusters, finding the system to be slightly more populous than average for galaxies of its luminosity. We find clear evidence for bimodality in the globular cluster colour distribution and for a colour-magnitude relation in the blue subpopulation (a 'blue tilt'). We also find negative radial colour gradients in both colour subpopulations of equal strength which are similar in strength to those reported in other galaxies. The sizes of NGC 4278's globular clusters decrease with redder colours and increase with galactocentric radius. The ratio of the sizes of blue to red globular clusters is independent of galactocentric radius demonstrating that internal effects are responsible...

  5. Catalogue of Large Magellanic Cloud star clusters observed in the Washington photometric system

    Science.gov (United States)

    Palma, T.; Gramajo, L. V.; Clariá, J. J.; Lares, M.; Geisler, D.; Ahumada, A. V.

    2016-02-01

    Aims: The main goal of this study is to compile a catalogue of the fundamental parameters of a complete sample of 277 star clusters (SCs) of the Large Magellanic Cloud (LMC) observed in the Washington photometric system. A set of 82 clusters was recently studied by our team. Methods: All the clusters' parameters such as radii, deprojected distances, reddenings, ages, and metallicities were obtained by applying essentially the same procedures, which are briefly described here. We used empirical cumulative distribution functions to examine age, metallicity and deprojected distance distributions for different cluster subsamples of the catalogue. Results: Our new sample of 82 additional clusters represents about a 40% increase in the total number of LMC SCs observed to date in the Washington photometric system. In particular, we report here the fundamental parameters obtained for the first time for 42 of these clusters. We found that single LMC SCs are typically older than multiple SCs. Both single and multiple SCs exhibit asymmetrical distributions in log (age). We compared cluster ages derived through isochrone fittings obtained using different models of the Padova group. Although ages obtained using recent isochrones are consistent in general terms, we found that there is some disagreement in the obtained values and their uncertainties.

  6. Evolution of star cluster systems in isolated galaxies: first results from direct $N$-body simulations

    CERN Document Server

    Rossi, L J; Hurley, J R

    2016-01-01

    The evolution of star clusters is largely affected by the tidal field generated by the host galaxy. It is thus in principle expected that under the assumption of an "universal" initial cluster mass function the properties of the evolved present-day mass function of star cluster systems should show a dependency on the properties of the galactic environment in which they evolve. To explore this expectation a sophisticated model of the tidal field is required in order to study the evolution of star cluster systems in realistic galaxies. Along these lines, in the present work we first describe a method developed for coupling $N$-body simulations of galaxies and star clusters. We then generate a database of galaxy models along the Hubble sequence and calibrate evolutionary equations to the results of direct $N$-body simulations of star clusters in order to predict the clusters' mass evolution as function of the galactic environment. We finally apply our methods to explore the properties of evolved "universal" init...

  7. Cluster consensus of second-order multi-agent systems via pinning control

    International Nuclear Information System (INIS)

    This paper investigates the cluster consensus problem for second-order multi-agent systems by applying the pinning control method to a small collection of the agents. Consensus is attained independently for different agent clusters according to the community structure generated by the group partition of the underlying graph and sufficient conditions for both cluster and general consensus are obtained by using results from algebraic graph theory and the LaSalle Invariance Principle. Finally, some simple simulations are presented to illustrate the technique. (general)

  8. Time-domain clustered transmit power adaptation for OFDM system in fading channels

    Institute of Scientific and Technical Information of China (English)

    GAN Xiao-ying; XU You-yun; GUAN Yun-feng; SONG Wen-tao

    2006-01-01

    This paper proposes a time-domain clustered transmitter power adaptation scheme for orthogonal frequency division multiplexing (OFDM) system, which can significantly reduce the feedback amount during power adaptation comparison with conventional frequency-domain adaptation schemes. It was found that the cluster size plays an important role on the adaptation performance, especially for the vehicular environment. Simulation results showed that using Lagrange interpolation to obtain an explicit curve of Doppler frequency vs cluster size yields good trade-offbetween the resulted bit error rate (BER) and the amount of feedback.

  9. Schedulability-Driven Frame Packing for Multi-Cluster Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2003-01-01

    also proposed a schedulability analysis for applications consisting of mixed event-triggered and time-triggered processes and messages, and a worst case queuing delay analysis for the gateways, responsible for routing inter-cluster traffic. Optimization heuristics for frame packing aiming at producing......We present an approach to frame packing for multi-cluster distributed embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. In our approach, the application messages are packed into frames such that the application is schedulable. Thus, we have...

  10. Schedulability-Driven Frame Packing for Multi-Cluster Distributed Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    also proposed a schedulability analysis for applications consisting of mixed event-triggered and time-triggered processes and messages, and a worst case queuing delay analysis for the gateways, responsible for routing inter-cluster traffic. Optimization heuristics for frame packing aiming at producing......We present an approach to frame packing for multi-cluster distributed embedded systems consisting of time-triggered and event-triggered clusters, interconnected via gateways. In our approach, the application messages are packed into frames such that the application is schedulable. Thus, we have...

  11. Cluster consensus of second-order multi-agent systems via pinning control

    Science.gov (United States)

    Lu, Xiao-Qing; Francis, Austin; Chen, Shi-Hua

    2010-12-01

    This paper investigates the cluster consensus problem for second-order multi-agent systems by applying the pinning control method to a small collection of the agents. Consensus is attained independently for different agent clusters according to the community structure generated by the group partition of the underlying graph and sufficient conditions for both cluster and general consensus are obtained by using results from algebraic graph theory and the LaSalle Invariance Principle. Finally, some simple simulations are presented to illustrate the technique.

  12. Formation of fullerene clusters in the system C{sub 60}/NMP/water by SANS

    Energy Technology Data Exchange (ETDEWEB)

    Aksenov, V.L. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation)]. E-mail: aksenov@nf.jinr.ru; Avdeev, M.V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Tropin, T.V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Korobov, M.V. [Department of Chemistry, Moscow State University (Russian Federation); Kozhemyakina, N.V. [Department of Chemistry, Moscow State University (Russian Federation); Avramenko, N.V. [Department of Chemistry, Moscow State University (Russian Federation); Rosta, L. [Research Institute for Solid State Physics and Optics, Budapest (Hungary)

    2006-11-15

    Solutions of fullerenes in nitrogen-containing solvents constitute a specific class characterized by the formation of fullerene clusters. In the given work, we report the effect of cluster rearrangement in the system C{sub 60}/N-methylpyrrolidone (NMP) after addition of water (miscible with NMP) as observed by small-angle neutron scattering (SANS). The effect has a critical character and takes place if the water relative content is higher than 40%. Despite a small scattering signal, estimates of the mean scattering length density of the clusters by SANS contrast variation can be done.

  13. Formation of fullerene clusters in the system C60/NMP/water by SANS

    International Nuclear Information System (INIS)

    Solutions of fullerenes in nitrogen-containing solvents constitute a specific class characterized by the formation of fullerene clusters. In the given work, we report the effect of cluster rearrangement in the system C60/N-methylpyrrolidone (NMP) after addition of water (miscible with NMP) as observed by small-angle neutron scattering (SANS). The effect has a critical character and takes place if the water relative content is higher than 40%. Despite a small scattering signal, estimates of the mean scattering length density of the clusters by SANS contrast variation can be done

  14. Evolution of star cluster systems in isolated galaxies: first results from direct $N$-body simulations

    OpenAIRE

    Rossi, L. J.; Bekki, K; Hurley, J. R.

    2016-01-01

    The evolution of star clusters is largely affected by the tidal field generated by the host galaxy. It is thus in principle expected that under the assumption of an "universal" initial cluster mass function the properties of the evolved present-day mass function of star cluster systems should show a dependency on the properties of the galactic environment in which they evolve. To explore this expectation a sophisticated model of the tidal field is required in order to study the evolution of s...

  15. Compact stellar systems in the Fornax cluster: a UV perspective

    CERN Document Server

    Mieske, Steffen; Bomans, Dominik J; Rey, Soo-Chang; Kim, Suk; Yoon, Suk-Jin; Chung, Chul

    2008-01-01

    In recent years, increasing evidence for chemical complexity and multiple stellar populations in massive globular clusters (GCs) has emerged, including extreme horizontal branches (EHBs) and UV excess. Our goal is to improve our understanding of UV excess in the regime of both massive GCs and ultra-compact dwarf galaxies (UCDs). To this end, we use deep archival GALEX data of the central Fornax cluster to measure NUV and FUV magnitudes of UCDs and massive GCs. We obtain NUV photometry for a sample of 35 compact objects with -13.5

  16. Availability and reliability of k-out-of-(M+N):G warm standby systems

    International Nuclear Information System (INIS)

    Redundancy or standby is a technique that has been widely applied to improving system reliability and availability in system design. In most cases, components in standby system are assumed to be statistically identical and independent. However, in many practical applications, not all components in standby can be treated as identical because they have different failure and repair rates. In this paper, one kind of such systems with two categories of components is studied, which is named k-out-of-(M+N):G warm standby system. In the system, one category of the components is of type 1 and the other type 2. There are M type 1 components and N type 2 components. Components of type 1 have a lower failure rate and are preferably repaired if there is one failed. There are r repair facilities available. By using Markov model, the system state transition process can be clearly illustrated, and furthermore, the solutions of system availability and reliability are obtained based on this. An example representing a power-generator and transmission system is given to illustrate the solutions of the system availability and reliability

  17. Beyond redundancy how geographic redundancy can improve service availability and reliability of computer-based systems

    CERN Document Server

    Bauer, Eric; Eustace, Dan

    2012-01-01

    "While geographic redundancy can obviously be a huge benefit for disaster recovery, it is far less obvious what benefit is feasible and likely for more typical non-catastrophic hardware, software, and human failures. Georedundancy and Service Availability provides both a theoretical and practical treatment of the feasible and likely benefits of geographic redundancy for both service availability and service reliability. The text provides network/system planners, IS/IT operations folks, system architects, system engineers, developers, testers, and other industry practitioners with a general discussion about the capital expense/operating expense tradeoff that frames system redundancy and georedundancy"--

  18. Availability modeling and optimization of dynamic multi-state series–parallel systems with random reconfiguration

    International Nuclear Information System (INIS)

    Most studies on multi-state series–parallel systems focus on the static type of system architecture. However, it is insufficient to model many complex industrial systems having several operation phases and each requires a subset of the subsystems combined together to perform certain tasks. To bridge this gap, this study takes into account this type of dynamic behavior in the multi-state series–parallel system and proposes an analytical approach to calculate the system availability and the operation cost. In this approach, Markov process is used to model the dynamics of system phase changing and component state changing, Markov reward model is used to calculate the operation cost associated with the dynamics, and universal generating function (UGF) is used to build system availability function from the system phase model and the component models. Based upon these models, an optimization problem is formulated to minimize the total system cost with the constraint that system availability is greater than a desired level. The genetic algorithm is then applied to solve the optimization problem. The proposed modeling and solution procedures are illustrated on a system design problem modified from a real-world maritime oil transportation system

  19. Development of Distributed Cache Strategy for Analytic Cluster in an Internet of Things System

    OpenAIRE

    Yang ZHOU

    2016-01-01

    This thesis discusses the development of a distributed cache strategy for an analyt-ic cluster in an IoT system. In this thesis, LRU and Proactive Cache and essential distributed system related concepts are discussed. The study about the approaches for performance optimization, nodes and data distributing in the IoT system are also included. In the IoT system, the cluster for data analysis involves large volume of data and some specific processes such as streaming processing raises a need ...

  20. The impact of galaxy harassment on the globular cluster systems of early-type cluster dwarf galaxies

    Science.gov (United States)

    Smith, R.; Sánchez-Janssen, R.; Fellhauer, M.; Puzia, T. H.; Aguerri, J. A. L.; Farias, J. P.

    2013-02-01

    The dynamics of globular cluster systems (GCSs) around galaxies are often used to assess the total enclosed mass, and even to constrain the dark matter distribution. The GCS of a galaxy is typically assumed to be in dynamical equilibrium within the potential of the host galaxy. However cluster galaxies are subjected to a rapidly evolving and, at times, violently destructive tidal field. We investigate the impact of the harassment on the dynamics of GCs surrounding early-type cluster dwarfs, using numerical simulations. We find that the dynamical behaviour of the GCS is strongly influenced by the fraction of bound dark matter fDM remaining in the galaxy. Only when fDM falls to ˜15 per cent do stars and GCs begin to be stripped. Still the observed GC velocity dispersion can be used to measure the true enclosed mass to within a factor of 2, even when fDM falls as low as ˜3 per cent. This is possible partly because unbound GCs quickly separate from the galaxy body. However even the distribution of bound GCs may spatially expand by a factor of 2-3. Once fDM falls into the <3 per cent regime, the galaxy is close to complete disruption, and GCS dynamics can no longer be used to reliably estimate the enclosed mass. In this regime, the remaining bound GCS may spatially expand by a factor of 4 to 8. It may be possible to test if a galaxy is in this regime by measuring the dynamics of the stellar disc. We demonstrate that if a stellar disc is rotationally supported, it is likely that a galaxy has sufficient dark matter that the dynamics of the GCS can be used to reliably estimate the enclosed mass.

  1. A High-Availability Architecture for the Dynamic Domain Name System

    OpenAIRE

    Filippi, Geoffrey George

    2008-01-01

    A High-Availability Architecture for the Dynamic Domain Name System DNS, DDNS, BGP, anycast, DHCP, replication, LDAP, multi-master, high-availability, reliability The Domain Name System (DNS) provides a mapping between host names and Internet Protocol (IP) addresses. Hosts that are configured using the Dynamic Host Configuration Protocol (DHCP) can have their assigned IP addresses updated in a Dynamic DNS (DDNS). DNS and DDNS are critical components of the Internet. Mos...

  2. Modeling of economically sustainable information security management systems in seaport clusters

    OpenAIRE

    Aksentijević, Saša; Tijan, Edvard; Čišić, Dragan

    2014-01-01

    The paper researches the usage of ARIS Express process modeling tool in creation of economically sustainable information security management system in seaport clusters. Basic concepts of information security in seaport cluster stakeholder’s organizations are detailed, and relations and interactions between organizations and their environment are researched. Portfolio approach to information security is being endorsed along with quantification of total levels of the risk and the resulting cost...

  3. Precise cloning and tandem integration of large polyketide biosynthetic gene cluster using Streptomyces artificial chromosome system

    OpenAIRE

    Nah, Hee-Ju; Woo, Min-Woo; Choi, Si-Sun; Kim, Eung-Soo

    2015-01-01

    Background Direct cloning combined with heterologous expression of a secondary metabolite biosynthetic gene cluster has become a useful strategy for production improvement and pathway modification of potentially valuable natural products present at minute quantities in original isolates of actinomycetes. However, precise cloning and efficient overexpression of an entire biosynthetic gene cluster remains challenging due to the ineffectiveness of current genetic systems in manipulating large-si...

  4. Round-Trip System Available to Measure Path Length Variation in Korea VLBI System for Geodesy

    Science.gov (United States)

    Oh, Hongjong; Kondo, Tetsuro; Lee, Jinoo; Kim, Tuhwan; Kim, Myungho; Kim, Suchul; Park, Jinsik; Ju, Hyunhee

    2010-01-01

    The construction project of Korea Geodetic VLBI officially started in October 2008. The construction of all systems will be completed by the end of 2011. The project was named Korea VLBI system for Geodesy (KVG), and its main purpose is to maintain the Korea Geodetic Datum. In case of the KVG system, an observation room with an H-maser frequency standard is located in a building separated from the antenna by several tens of meters. Therefore KVG system will adopt a so-called round-trip system to transmit reference signals to the antenna with reduction of the effect of path length variations. KVG s round-trip system is designed not only to use either metal or optical fiber cables, but also to measure path length variations directly. We present this unique round trip system for KVG.

  5. Application of the symbolic manipulation program REDUCE to system availability analyses

    International Nuclear Information System (INIS)

    Many symbolic manipulation computer programs have been developed to perform complicated algebraic manipulations. Among them REDUCE is readily available for users of the CRAY computers at the National Magnetic Fusion Energy Computer Center, Livermore, California. In this paper applications of REDUCE in nuclear power plant system availability analyses are discussed. An imaginative reader might find other useful applications

  6. 75 FR 25239 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2010-05-07

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... of literature searches for IRIS assessments; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of literature searches for four IRIS assessments...

  7. 77 FR 41784 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2012-07-16

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... literature search for benzo(a)pyrene; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of a literature search for benzo(a)pyrene (CASRN 50-...

  8. 76 FR 13402 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2011-03-11

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... literature searches for IRIS assessments; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of literature searches for cobalt (CASRN 7440-48-4)...

  9. 77 FR 20817 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2012-04-06

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... literature searches for IRIS assessments; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of literature searches for acetaldehyde (75-07-0) and...

  10. Aircraft ride quality controller design using new robust root clustering theory for linear uncertain systems

    Science.gov (United States)

    Yedavalli, R. K.

    1992-01-01

    The aspect of controller design for improving the ride quality of aircraft in terms of damping ratio and natural frequency specifications on the short period dynamics is addressed. The controller is designed to be robust with respect to uncertainties in the real parameters of the control design model such as uncertainties in the dimensional stability derivatives, imperfections in actuator/sensor locations and possibly variations in flight conditions, etc. The design is based on a new robust root clustering theory developed by the author by extending the nominal root clustering theory of Gutman and Jury to perturbed matrices. The proposed methodology allows to get an explicit relationship between the parameters of the root clustering region and the uncertainty radius of the parameter space. The current literature available for robust stability becomes a special case of this unified theory. The bounds derived on the parameter perturbation for robust root clustering are then used in selecting the robust controller.

  11. Fault detection of flywheel system based on clustering and principal component analysis

    Institute of Scientific and Technical Information of China (English)

    Wang Rixin; Gong Xuebing; Xu Minqiang; Li Yuqing

    2015-01-01

    Considering the nonlinear, multifunctional properties of double-flywheel with closed-loop control, a two-step method including clustering and principal component analysis is proposed to detect the two faults in the multifunctional flywheels. At the first step of the proposed algorithm, clustering is taken as feature recognition to check the instructions of‘‘integrated power and attitude control”system, such as attitude control, energy storage or energy discharge. These commands will ask the flywheel system to work in different operation modes. Therefore, the relationship of parameters in different operations can define the cluster structure of training data. Ordering points to identify the clustering structure (OPTICS) can automatically identify these clusters by the reachability-plot. K-means algorithm can divide the training data into the corresponding operations according to the reachability-plot. Finally, the last step of proposed model is used to define the rela-tionship of parameters in each operation through the principal component analysis (PCA) method. Compared with the PCA model, the proposed approach is capable of identifying the new clusters and learning the new behavior of incoming data. The simulation results show that it can effectively detect the faults in the multifunctional flywheels system.

  12. Clustered chimera states in systems of type-I excitability

    International Nuclear Information System (INIS)

    The chimera state is a fascinating phenomenon of coexisting synchronized and desynchronized behaviour that was discovered in networks of nonlocally coupled identical phase oscillators over ten years ago. Since then, chimeras have been found in numerous theoretical and experimental studies and more recently in models of neuronal dynamics as well. In this work, we consider a generic model for a saddle-node bifurcation on a limit cycle representative of neural excitability type I. We obtain chimera states with multiple coherent regions (clustered chimeras/multi-chimeras) depending on the distance from the excitability threshold, the range of nonlocal coupling and the coupling strength. A detailed stability diagram for these chimera states and other interesting coexisting patterns (like traveling waves) is presented. (paper)

  13. Influence of system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas

    International Nuclear Information System (INIS)

    Influence of the system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas is investigated through laboratory experiment and molecular dynamics simulation. The micro-structures, defect numbers, and pair correlation function of the dust clusters are studied for different system temperatures. The dust grains' trajectories, the mean square displacement, and the corresponding self-diffusion coefficient of the clusters are calculated for different temperatures for illustrating the phase properties of the dust clusters. The simulation results confirm that with the increase in system temperature, the micro-structures and dynamics of dust clusters are gradually changed, which qualitatively agree with experimental results

  14. Application of clustering techniques to study environmental characteristics of microbialite-bearing aquatic systems

    Directory of Open Access Journals (Sweden)

    R. Dalinina

    2015-07-01

    Full Text Available Microbialites are a product of trapping and binding of sediment by microbial communities, and are considered to be some of the most ancient records of life on Earth. It is a commonly held belief that microbialites are limited to extreme, hypersaline settings. However, more recent studies report their occurrence in a wider range of environments. The goal of this study is to explore whether microbialite-bearing sites share common geochemical properties. We apply statistical techniques to distinguish any common traits in these environments. These techniques ultimately could be used to address questions of microbialite distribution: are microbialites restricted to environments with specific characteristics; or are they more broadly distributed? A dataset containing hydrographic characteristics of several microbialite sites with data on pH, conductivity, alkalinity, and concentrations of several major anions and cations was constructed from previously published studies. In order to group the water samples by their natural similarities and differences, a clustering approach was chosen for analysis. k means clustering with partial distances was applied to the dataset with missing values, and separated the data into two clusters. One of the clusters is formed by samples from atoll Kiritimati (central Pacific Ocean, and the second cluster contains all other observations. Using these two clusters, the missing values were imputed by k nearest neighbor method, producing a complete dataset that can be used for further multivariate analysis. Salinity is not found to be an important variable defining clustering, and although pH defines clustering in this dataset, it is not an important variable for microbialite formation. Clustering and imputation procedures outlined here can be applied to an expanded dataset on microbialite characteristics in order to determine properties associated with microbialite-containing environments.

  15. Using New Instruments of Clustering Policy in the Health Care System. The Case of Poland

    Science.gov (United States)

    Romaniuk, Piotr; Holecki, Tomasz; Woźniak-Holecka, Joanna

    2016-01-01

    The issue of clusters as a form of organization of market entities has recently attracted an increasing attention of health care management theoreticians and practitioners. In our opinion the existing theoretical basis gives a foundation for considering clusters as a source of potential for increasing the effectiveness of health policy and health care organizations. It can be assumed that in case of health care clusters there is a possibility of interregional diffusion of innovation, based on ventures undertaken on the health care market, increasing not only the potential of the entities in the cluster, but also of its surroundings and subcontractors. It is possible to realize the idea of a flexible health care implemented regionally with the use of modern techniques of communication, knowledge transfer and high specialization. Nonetheless, in case of Poland the potential of clustrification remains untapped, being characterized by a limited actions of public and private bodies, marginal role of non-profit sector organizations and limited engagement of R&D sector. This is because a general distrust in the cluster formula, and the lack of relevant knowledge among local officials and health business leaders. For this reason the process of clustrification among health care entities requires external support through the increased efforts to create a system of legal and tax preferences for cluster initiatives and provision of organizational support in terms of know-how, targeted particularly at bodies and individuals, who may act as cluster leaders.

  16. Using New Instruments of Clustering Policy in the Health Care System. The Case of Poland.

    Science.gov (United States)

    Romaniuk, Piotr; Holecki, Tomasz; Woźniak-Holecka, Joanna

    2016-01-01

    The issue of clusters as a form of organization of market entities has recently attracted an increasing attention of health care management theoreticians and practitioners. In our opinion the existing theoretical basis gives a foundation for considering clusters as a source of potential for increasing the effectiveness of health policy and health care organizations. It can be assumed that in case of health care clusters there is a possibility of interregional diffusion of innovation, based on ventures undertaken on the health care market, increasing not only the potential of the entities in the cluster, but also of its surroundings and subcontractors. It is possible to realize the idea of a flexible health care implemented regionally with the use of modern techniques of communication, knowledge transfer and high specialization. Nonetheless, in case of Poland the potential of clustrification remains untapped, being characterized by a limited actions of public and private bodies, marginal role of non-profit sector organizations and limited engagement of R&D sector. This is because a general distrust in the cluster formula, and the lack of relevant knowledge among local officials and health business leaders. For this reason the process of clustrification among health care entities requires external support through the increased efforts to create a system of legal and tax preferences for cluster initiatives and provision of organizational support in terms of know-how, targeted particularly at bodies and individuals, who may act as cluster leaders. PMID:27445815

  17. Dynamical evolution of black hole sub-systems in idealised star clusters

    CERN Document Server

    Breen, Philip G

    2013-01-01

    In this paper, globular star clusters which contain a sub-system of stellar-mass black holes (BH) are investigated. This is done by considering two-component models, as these are the simplest approximation of more realistic multi-mass systems, where one component represents the BH population and the other represents all the other stars. These systems are found to undergo a long phase of evolution where the centre of the system is dominated by a dense BH sub-system. After mass segregation has driven most of the BH into a compact sub-system, the evolution of the BH sub-system is found to be influenced by the cluster in which it is contained. The BH sub-system evolves in such a way as to satisfy the energy demands of the whole cluster, just as the core of a one component system must satisfy the energy demands of the whole cluster. The BH sub-system is found to exist for a significant amount of time. It takes approximately 10t_{rh,i}, where t_{rh,i} is the initial half-mass relaxation time, from the formation of ...

  18. Function and Regulation of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR / CRISPR Associated (Cas Systems

    Directory of Open Access Journals (Sweden)

    Peter C. Fineran

    2012-10-01

    Full Text Available Phages are the most abundant biological entities on earth and pose a constant challenge to their bacterial hosts. Thus, bacteria have evolved numerous ‘innate’ mechanisms of defense against phage, such as abortive infection or restriction/modification systems. In contrast, the clustered regularly interspaced short palindromic repeats (CRISPR systems provide acquired, yet heritable, sequence-specific ‘adaptive’ immunity against phage and other horizontally-acquired elements, such as plasmids. Resistance is acquired following viral infection or plasmid uptake when a short sequence of the foreign genome is added to the CRISPR array. CRISPRs are then transcribed and processed, generally by CRISPR associated (Cas proteins, into short interfering RNAs (crRNAs, which form part of a ribonucleoprotein complex. This complex guides the crRNA to the complementary invading nucleic acid and targets this for degradation. Recently, there have been rapid advances in our understanding of CRISPR/Cas systems. In this review, we will present the current model(s of the molecular events involved in both the acquisition of immunity and interference stages and will also address recent progress in our knowledge of the regulation of CRISPR/Cas systems.

  19. The SLUGGS Survey: NGC 3115, A Critical Test Case for Metallicity Bimodality in Globular Cluster Systems

    CERN Document Server

    Brodie, Jean P; Conroy, Charlie; Strader, Jay; Arnold, Jacob A; Forbes, Duncan A; Romanowsky, Aaron J

    2012-01-01

    Due to its proximity (9 Mpc) and the strongly bimodal color distribution of its spectroscopically well-sampled globular cluster (GC) system, the early-type galaxy NGC 3115 provides one of the best available tests of whether the color bimodality widely observed in GC systems generally reflects a true metallicity bimodality. Color bimodality has alternatively been attributed to a strongly nonlinear color--metallicity relation reflecting the influence of hot horizontal branch stars. Here we couple Subaru Suprime-Cam gi photometry with Keck/DEIMOS spectroscopy to accurately measure GC colors and a CaT index that measures the CaII triplet. We find the NGC 3115 GC system to be unambiguously bimodal in both color and the CaT index. Using simple stellar population models, we show that the CaT index is essentially unaffected by variations in horizontal branch morphology over the range of metallicities relevant to GC systems (and is thus a robust indicator of metallicity) and confirm bimodality in the metallicity distr...

  20. THE SLUGGS SURVEY: NGC 3115, A CRITICAL TEST CASE FOR METALLICITY BIMODALITY IN GLOBULAR CLUSTER SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, Jean P.; Conroy, Charlie; Arnold, Jacob A.; Romanowsky, Aaron J. [University of California Observatories and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Usher, Christopher; Forbes, Duncan A. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Strader, Jay, E-mail: brodie@ucolick.org [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

    2012-11-10

    Due to its proximity (9 Mpc) and the strongly bimodal color distribution of its spectroscopically well-sampled globular cluster (GC) system, the early-type galaxy NGC 3115 provides one of the best available tests of whether the color bimodality widely observed in GC systems generally reflects a true metallicity bimodality. Color bimodality has alternatively been attributed to a strongly nonlinear color-metallicity relation reflecting the influence of hot horizontal-branch stars. Here, we couple Subaru Suprime-Cam gi photometry with Keck/DEIMOS spectroscopy to accurately measure GC colors and a CaT index that measures the Ca II triplet. We find the NGC 3115 GC system to be unambiguously bimodal in both color and the CaT index. Using simple stellar population models, we show that the CaT index is essentially unaffected by variations in horizontal-branch morphology over the range of metallicities relevant to GC systems (and is thus a robust indicator of metallicity) and confirm bimodality in the metallicity distribution. We assess the existing evidence for and against multiple metallicity subpopulations in early- and late-type galaxies and conclude that metallicity bi/multimodality is common. We briefly discuss how this fundamental characteristic links directly to the star formation and assembly histories of galaxies.

  1. Metrics for Service Availability and Service Reliability in Service-oriented Intelligence Information System,

    OpenAIRE

    Ackoski, Jugoslav; Trajkovik, Vladimir

    2012-01-01

    Intelligence Information System (IIS) proposed in this paper is based on service-oriented architecture. This paper gives contribution in definition of metrics for service reliability and service availability in terms of their usage by the end-user. Developed metrics for services have significant meaning for service-oriented Intelligence Information System.

  2. Non-parametric estimation of the availability in a general repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Gamiz, M.L. [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)], E-mail: mgamiz@ugr.es; Roman, Y. [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)

    2008-08-15

    This work deals with repairable systems with unknown failure and repair time distributions. We focus on the estimation of the instantaneous availability, that is, the probability that the system is functioning at a given time, which we consider as the most significant measure for evaluating the effectiveness of a repairable system. The estimation of the availability function is not, in general, an easy task, i.e., analytical techniques are difficult to apply. We propose a smooth estimation of the availability based on kernel estimator of the cumulative distribution functions (CDF) of the failure and repair times, for which the bandwidth parameters are obtained by bootstrap procedures. The consistency properties of the availability estimator are established by using techniques based on the Laplace transform.

  3. Non-parametric estimation of the availability in a general repairable system

    International Nuclear Information System (INIS)

    This work deals with repairable systems with unknown failure and repair time distributions. We focus on the estimation of the instantaneous availability, that is, the probability that the system is functioning at a given time, which we consider as the most significant measure for evaluating the effectiveness of a repairable system. The estimation of the availability function is not, in general, an easy task, i.e., analytical techniques are difficult to apply. We propose a smooth estimation of the availability based on kernel estimator of the cumulative distribution functions (CDF) of the failure and repair times, for which the bandwidth parameters are obtained by bootstrap procedures. The consistency properties of the availability estimator are established by using techniques based on the Laplace transform

  4. Designing high availability systems DFSS and classical reliability techniques with practical real life examples

    CERN Document Server

    Taylor, Zachary

    2014-01-01

    A practical, step-by-step guide to designing world-class, high availability systems using both classical and DFSS reliability techniques Whether designing telecom, aerospace, automotive, medical, financial, or public safety systems, every engineer aims for the utmost reliability and availability in the systems he, or she, designs. But between the dream of world-class performance and reality falls the shadow of complexities that can bedevil even the most rigorous design process. While there are an array of robust predictive engineering tools, there has been no single-source guide to understan

  5. The formation of higher-order hierarchical systems in star clusters

    CERN Document Server

    van den Berk, J; McMillan, S; Berk, Jelle van den; Zwart, Simon Portegies; Millan, Steve Mc

    2006-01-01

    We simulate open clusters containing up to 182 stars initially in the form of singles, binaries and triples. Due to the high interaction rate a large number of stable quadruples, quintuples, sextuples, and higher-order hierarchies form during the course of the simulations. For our choice of initial conditions, the formation rate of quadruple systems after about 2Myr is roughly constant with time at about 0.008 per cluster per Myr. The formation rate of quintuple and sextuple systems are about half and one quarter, respectively, of the quadruple formation rate, and both rates are also approximately constant with time. We present reaction channels and relative probabilities for the formation of persistent systems containing up to six stars. The reaction networks for the formation and destruction of quintuple and sextuple systems can become quite complicated, although the branching ratios remain largely unchanged during the course of the cluster evolution. The total numbers of quadruples is about a factor of thr...

  6. An artificial neural network for modeling reliability, availability and maintainability of a repairable system

    International Nuclear Information System (INIS)

    The paper explores the application of artificial neural networks to model the behaviour of a complex, repairable system. A composite measure of reliability, availability and maintainability parameters has been proposed for measuring the system performance. The artificial neural network has been trained using past data of a helicopter transportation facility. It is used to simulate behaviour of the facility under various constraints. The insights obtained from results of simulation are useful in formulating strategies for optimal operation of the system

  7. Reliability and availability considerations in the RF systems of ATW-class accelerators

    International Nuclear Information System (INIS)

    In an RF-driven, ion accelerator for waste transmutation or nuclear material production, the overall availability is perhaps the most important specification. The synchronism requirements in an ion accelerator, as contrasted to an electron accelerator, cause a failure of an RF source to have a greater consequence. These large machines also are major capital investments, so the availability determines the return on this capital. RF system design methods to insure a high availability without paying a serious cost penalty are the subject of this paper. The overall availability goal in the present designs is 75% for the entire ATW complex, and from 25 to 35% of the unavailability is allocated to the RF system, since it is one of the most complicated subsystems in the complex. The allowed down time for the RF system (including the linac and all other systems) is then only 7 to 9% of the operating time per year, or as little as 613 hours per year, for continuous operation. Since large accelerators consume large amounts of electrical power, excellent efficiency is also required with the excellent availability. The availability also influences the sizes of the RF components; smaller components may fail and yet the accelerator may still meet all specifications. Larger components are also attractive, since the cost of an RF system usually increases as the square root of the number of RF systems utilized. In some cases, there is a reliability penalty that accompanies the cost savings from using larger components. The authors discuss these factors, and present an availability model that allows one to examine these trade offs, and make rational choices in the RF and accelerator system designs

  8. Availability analysis of nuclear power system with performance degradation and multi-level support capacity

    International Nuclear Information System (INIS)

    The availability analysis which combines universal generating function (UGF) with Markov state transition theory was proposed to nuclear power system with performance degradation and multi-level support capacity. The system logical model and performance state combination model were constructed by UGF. Furthermore, the computational expression for component state probability based on Markov method was constructed considering performance degradation and multi-level support capacity. And then the model was embedded into the logic model and performance state combination model by UGF. This combined model was used in availability analysis of an actual example with different performance demands, and the influence of maintenance condition to system availability was also analyzed. The results show that this method captures the operational and maintenance characteristics. The obtained results can provide guidance to nuclear power system operation, management, maintenance decision-making and support condition analysis. (authors)

  9. Proteomic Analysis of Protein-Protein Interactions within the CSD Fe-S Cluster Biogenesis System

    OpenAIRE

    Bolstad, Heather M.; Botelho, Danielle J.; Wood, Matthew J.

    2010-01-01

    Fe-S cluster biogenesis is of interest to many fields, including bioenergetics and gene regulation. The CSD system is one of three Fe-S cluster biogenesis systems in E. coli and is comprised of the cysteine desulfurase CsdA, the sulfur acceptor protein CsdE, and the E1-like protein CsdL. The biological role, biochemical mechanism, and protein targets of the system remain uncharacterized. Here we present that the active site CsdE C61 has a lowered pKa value of 6.5, which is nearly identical to...

  10. Simulation a decision support tool in maintenance float systemssystem availability versus total maintenance cost

    OpenAIRE

    Peito, Francisco; Pereira, Guilherme; Leitão, Armando; Dias, Luís M. S.

    2011-01-01

    This paper is concerned with the use of simulation as a decision support tool in maintenance systems, specifically in MFS (Maintenance Float Systems). For this purpose and due to its high complexity, in this paper the authors explore and present a possible way to construct a MFS model using Arena® simulation language, where some of the most common performance measures are identified, calculated and analysed. Nevertheless this paper would concentrate on the two most important performance me...

  11. Simulation as a decision support tool in maintenance float systems : system availability versus total maintenance cost

    OpenAIRE

    Pereira, Guilherme; Peito, Francisco; Leitão, Armando; Dias, Luís M. S.

    2011-01-01

    This paper is concerned with the use of simulation as a decision support tool in maintenance systems, specifically in MFS (Maintenance Float Systems). For this purpose and due to its high complexity, in this paper the authors explore and present a possible way to construct a MFS model using Arena® simulation language, where some of the most common performance measures are identified, calculated and analysed. Nevertheless this paper would concentrate on the two most important performance measu...

  12. Reliability and availability considerations in the RF systems of ATW-class accelerators

    Science.gov (United States)

    Tallerico, Paul J.; Lynch, Michael T.; Lawrence, George

    1995-09-01

    In an RF-driven, ion accelerator for waste transmutation or nuclear material production, the overall availability is perhaps the most important specification. The synchronism requirements in an ion accelerator, as contrasted to an electron accelerator, cause a failure of an RF source to have a greater consequence. These large machines also are major capital investments, so the availability determines the return on this capital. RF system design methods to insure a high availability without paying a serious cost penalty are the subject of this paper. The overall availability goal in our present designs is 75% for the entire ATW complex, and from 25 to 35% of the unavailability is allocated to the RF system, since it is one of the most complicated subsystems in the complex. The allowed down time for the RF system (including the linac and all other subsystems) is then only 7 to 9% of the operating time per year, or as little as 613 hours per year, for continuous operation. Since large accelerators consume large amounts of electrical power, excellent efficiency is also required with the excellent availability. The availability also influences the sizes of the RF components: smaller components may fail and yet the accelerator may still meet all specifications. Larger components are also attractive, since the cost of an RF system usually increases as the square root of the number of RF systems utilized. In some cases, there is a reliability penalty that accompanies the cost savings from using larger components. We discuss these factors, and present an availability model that allows one to examine these trade offs, and make rational choices in the RF and accelerator system designs.

  13. Building highly available control system applications with Advanced Telecom Computing Architecture and open standards

    International Nuclear Information System (INIS)

    Requirements for modern and future control systems for large projects like International Linear Collider demand high availability for control system components. Recently telecom industry came up with a great open hardware specification - Advanced Telecom Computing Architecture (ATCA). This specification is aimed for better reliability, availability and serviceability. Since its first market appearance in 2004, ATCA platform has shown tremendous growth and proved to be stable and well represented by a number of vendors. ATCA is an industry standard for highly available systems. On the other hand Service Availability Forum, a consortium of leading communications and computing companies, describes interaction between hardware and software. SAF defines a set of specifications such as Hardware Platform Interface, Application Interface Specification. SAF specifications provide extensive description of highly available systems, services and their interfaces. Originally aimed for telecom applications, these specifications can be used for accelerator controls software as well. This study describes benefits of using these specifications and their possible adoption to accelerator control systems. It is demonstrated how EPICS Redundant IOC was extended using Hardware Platform Interface specification, which made it possible to utilize benefits of the ATCA platform.

  14. Application of Fuzzy Clustering in Modeling of a Water Hydraulics System

    DEFF Research Database (Denmark)

    Zhou, Jianjun; Kroszynski, Uri

    2000-01-01

    This article presents a case study of applying fuzzy modeling techniques for a water hydraulics system. The obtained model is intended to provide a basis for model-based control of the system. Fuzzy clustering is used for classifying measured input-output data points into partitions. The fuzzy...

  15. Clustering, concurrency control, crash recovery, garbage collection, and security in object-oriented database management systems

    OpenAIRE

    de Paula, Everton, G.; Nelson, Michael L.

    1991-01-01

    This paper presents considerations about several topics that have a direct influence on data reliability and performance in object oriented database management systems. These topics are: physical storage management (clustering), concurrency control, crash recovery, garbage collection, and database security. Each topic is illustrated by its application to the Tactical Database as designed for the Low Cost Combat Direction System

  16. Heat flux from magmatic hydrothermal systems related to availability of fluid recharge

    Science.gov (United States)

    Harvey, M. C.; Rowland, J. V.; Chiodini, G.; Rissmann, C. F.; Bloomberg, S.; Hernández, P. A.; Mazot, A.; Viveiros, F.; Werner, C.

    2015-09-01

    Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with heat flux. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and heat flux interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system heat output to rainfall catchment area. This result highlights the importance of recharge as a consideration when evaluating hydrothermal systems for electricity generation, and the utility of CO2 flux as a resource evaluation tool.

  17. Reliability and availability analysis of two alternative evacuation systems designed for the Next European Torus (NET)

    International Nuclear Information System (INIS)

    This paper discusses the reliability and availability issues in case of two different evacuation system designs which have been proposed for the Next European Torus (NET). One of these designs uses turbo molecular pumps while the other employs cryogenic pumps to evacuate waste products from the torus after every fusion cycle. The aim of this paper is to assess and compare the feasibility of the above two designs form the reliability and availability point of view. A detailed failure mode analysis has been carried out for these two systems and appropriate mathematical mdoels have been developed to calculate their respective reliabilities. Using these mathematical models an extensive parameter study of the system reliability has been carried out over a given range of the component reliabilities. This parameter study shows that the maximum value of the turbo molecular pump system reliability is 96% while the corresponding value for the cryogenic pump system is only 81.6%. The target value for the system availability is 99.9%. This requires that the system mean repair time should be 48 h, appropriate modifications must be made to the turbo pump system design to increase its reliability accordingly. (author). 4 refs.; 10 figs

  18. Impact of Water Availability on Regional Power System Operations - A Case Study of ERCOT

    Science.gov (United States)

    Levin, T.; Zhou, Z.

    2015-12-01

    Impact of water availability on regional power system operations - A case study of ERCOT Thermal power plants are the largest single source of water withdrawals in the United States, mainly for cooling purposes. The amount of water that is required for cooling is highly dependent on a number of factors including the generation technologies being used, the temperature of the input water, and the total electricity load in the system. During summer months, many of these factors coincide to greatly increase the demand for water in a power system. Electricity demand typically reaches its annual peak when temperatures are high due to increased air conditioning loads. Ambient water temperatures also increase, meaning that greater quantities of water are required to provide the same amount of cooling at thermal generation plants. Finally, water availability is generally constrained due to seasonal effects and potential droughts. This raises concerns that water scarcity may lead to forced de-rating at some power plants during periods of peak demand, resulting in a more vulnerable and less reliable energy system. While increasing attention has recently been given to the inexorable link between water and energy, most commercial power models do not explicitly account for water use when optimizing system operation. We apply the AURORAxmp power modeling software to a case study analysis of the ERCOT power system to determine the water requirements of the system during periods of peak power demand. We then analyze water availability by location and time to identify potential supply shortages, which may reduce actual power generation availability. These data are fed back into the power systems model and specific generation units are de-rated as necessitated by water constraints. We then analyze these results to determine how the optimal generation mix, system reliability, and wholesale electricity prices may be affected by when the ERCOT power system is operated under water

  19. Phantom evaluation of a commercially available three modality image guided radiation therapy system

    International Nuclear Information System (INIS)

    The authors describe a detailed evaluation of the capabilities of imaging and image registration systems available with Varian linear accelerators for image guided radiation therapy (IGRT). Specifically, they present modulation transfer function curves for megavoltage planar, kilovoltage (kV) planar, and cone beam computed tomography imaging systems and compare these with conventional computed tomography. While kV planar imaging displayed the highest spatial resolution, all IGRT imaging techniques were assessed as adequate for their intended purpose. They have also characterized the image registration software available for use in conjunction with these imaging systems through a comprehensive phantom study involving translations in three orthogonal directions. All combinations of imaging systems and image registration software were found to be accurate, although the planar kV imaging system with automatic registration was generally superior, with both accuracy and precision of the order of 1 mm, under the conditions tested. Based on their phantom study, the attainable accuracy for rigid body translations using any of the features available with Varian equipment will more likely be limited by the resolution of the couch readouts than by inherent limitations in the imaging systems and image registration software. Overall, the accuracy and precision of currently available IGRT technology exceed published experience with the accuracy and precision of contouring for planning.

  20. Intervention to Improve Biosecurity System of Poultry Production Clusters (PPCs in Thailand

    Directory of Open Access Journals (Sweden)

    Worapol Aengwanich

    2014-08-01

    Full Text Available Widespread outbreaks of avian influenza occurred in 2004–2005. The outbreaks resulted in extensive losses for the poultry sector in East and South East Asia. Thailand suffered a tremendous impact from the disease. Later, in 2006, there was another outbreak of the aforementioned disease in poultry production clusters (PPCs in Nakhon Phanom province in the northeastern region of Thailand. In this study, we conducted an intervention by working together with the Department of Livestock Development officials to improve the biosecurity level of PPCs in this province. The methods employed in the intervention included meetings to build understanding and hear about various ideas and problems among stakeholders; instructions; having the farmers perform self-evaluations of the level of biosecurity on the farms; and measures for motivating farmers, e.g., farm contests and handing out awards. The results revealed the following information: After intervention, attraction to wild bird of poultry farms in PPCs decreased (p < 0.05, because the farmers cut down trees around farm and poultry housing. Moreover, biosecurity system planning inside farms in PPCs increased (p < 0.05. The scores for biosecurity system planning inside farms that increased following the intervention are a positive sign that farmers will continue to develop better biosecurity systems on their farms.

  1. Availability-based computer management of a cold thermal storage system

    International Nuclear Information System (INIS)

    This paper reports on work to develop an availability-based, on-line expert system to manage a thermal energy storage air-conditioning system. The management system is designed to be used by mechanical engineers in the field of air-conditioning control and maintenance. Specifically, the expert system permits the user to easily monitor the second law of thermodynamics operating efficiencies of the major components and the system as a whole in addition to the daily scheduled operating parameters of a cold thermal storage system. Through the use of computer-generated and continually updated screen display pages, the user is permitted interaction with the expert system. The knowledge-based system is developed with a commercially available expert system shell that is resident in a personal computer. In the case studied, 130 various analog and binary inputs/outputs are used. The knowledge base for the thermal energy storage expert system included nine different display pages that are continually updated, 25 rules, three tasks, and three loops

  2. Adaptive Lockable Units to Improve Data Availability in a Distributed Database System

    Directory of Open Access Journals (Sweden)

    Khaled Maabreh

    2016-01-01

    Full Text Available Distributed database systems have become a phenomenon and have been considered a crucial source of information for numerous users. Users with different jobs are using such systems locally or via the Internet to meet their professional requirements. Distributed database systems consist of a number of sites connected over a computer network. Each site deals with its own database and interacts with other sites as needed. Data replication in these systems is considered a key factor in improving data availability. However, it may affect system performance when most of the transactions that access the data contain write or a mix of read and write operations because of exclusive locks and update propagation. This research proposes a new adaptive approach for increasing the availability of data contained in a distributed database system. The proposed approach suggests a new lockable unit by increasing the database hierarchy tree by one level to include attributes as lockable units instead of the entire row. This technique may allow several transactions to access the database row simultaneously by utilizing some attributes and keeping others available for other transactions. Data in a distributed database system can be accessed locally or remotely by a distributed transaction, with each distributed transaction decomposed into several sub-transactions called participants or agents. These agents access the data at multiple sites and must guarantee that any changes to the data must be committed in order to complete the main transaction. The experimental results show that using attribute-level locking will increase data availability, reliability, and throughput, as well as enhance overall system performance. Moreover, it will increase the overhead of managing such a large number of locks, which will be managed according to the qualification of the query.

  3. Architecture for Interlock Systems Reliability Analysis with Regard to Safety and Availability

    CERN Document Server

    Wagner, S; Schmidt, R; Zerlauth, M; Vergara-Fernandez, A

    2011-01-01

    In the design of interlock loops for the signal exchange in machine protection systems, the choice of the hardware architecture impacts on machine safety and availability. The reliable performance of a machine stop (leaving the machine in a safe state) in case of an emergency, is an inherent requirement. The constraints in terms of machine availability on the other hand may differ from one facility to another. Spurious machine stops, lowering machine availability, may to a certain extent be tolerated in facilities where they do not cause undue equipment wearout. In order to compare various interlock loop architectures in terms of safety and availability, the occurrence frequencies of related scenarios have been calculated in a reliability analysis, using a generic analytical model. This paper presents the results and illustrates the potential of the analysis method for supporting the choice of interlock system architectures.

  4. The nuclear plant reliability data system data usage in availability engineering

    International Nuclear Information System (INIS)

    Applications of technology of the reliability, availability and maintainability engineering disciplines are taking place between the aerospace and electrical utility industry. Included in these activities is the use of available data in generating solutions to various problems. In this paper deterministic methodology is applied to data collected for the Nuclear Plant Reliability Data System to illustrate the use of such data in problem solving. The results of this exercise demonstrate the feasibility of obtaining point estimates with large confidence levels

  5. Analyzing the service availability of mobile cloud computing systems by fluid-flow approximation

    Institute of Scientific and Technical Information of China (English)

    Hong-wu LV; Jun-yu LIN; Hui-qiang WANG; Guang-sheng FENG; Mo ZHOU

    2015-01-01

    Mobile cloud computing (MCC) has become a promising technique to deal with computation- or data-intensive tasks. It overcomes the limited processing power, poor storage capacity, and short battery life of mobile devices. Providing con-tinuous and on-demand services, MCC argues that the service must be available for users at anytime and anywhere. However, at present, the service availability of MCC is usually measured by some certain metrics of a real-world system, and the results do not have broad representation since different systems have different load levels, different deployments, and many other random factors. Meanwhile, for large-scale and complex types of services in MCC systems, simulation-based methods (such as Monte-Carlo simulation) may be costly and the traditional state-based methods always suffer from the problem of state-space explosion. In this paper, to overcome these shortcomings, fluid-flow approximation, a breakthrough to avoid state-space explosion, is adopted to analyze the service availability of MCC. Four critical metrics, including response time of service, minimum sensing time of devices, minimum number of nodes chosen, and action throughput, are defined to estimate the availability by solving a group of ordinary differential equations even before the MCC system is fully deployed. Experimental results show that our method costs less time in analyzing the service availability of MCC than the Markov- or simulation-based methods.

  6. Kinematic studies of disk galaxies inside and around the Abell 901/902 cluster system

    International Nuclear Information System (INIS)

    This thesis examines the region around the Abell 901/902 multiple cluster system. It is located at a redshift of z⁓0.165, which corresponds to a look-back time of around two billion years. The multiple cluster system comprises four subclusters, but it also includes infalling groups and further filaments. Exploiting multi-object slit spectra and galaxy rotation curves we investigate the dynamics of the multiple cluster system as well as the kinematics of our spectroscopic target galaxies. We compare the field with the cluster population and particularly investigate dusty red galaxies, a galaxy population with reduced star-formation rates compared to normal spiral galaxies. In the field environment galaxies with large morphological asymmetries have also more distorted rotation curves. Tidal interactions most probably are responsible for this trend. In the cluster environment, however, we find a significant fraction of galaxies with smooth stellar disks but highly disturbed kinematics. The effects of ram-pressure stripping, disturbing the gas and stripping part of its reservoir but not affecting the stars, are the best explanation for this finding. At a given mass cluster galaxies are fainter in the B-band than field galaxies. This might be due to environmental effects. We find enhanced kinematic distortions and a larger scatter in the luminosity-rotation velocity (Tully-Fisher) relation for galaxies residing closer to the cluster core. Depending on the gas content of a galaxy, an enhancement or suppression of star-formation rates e.g. due to ram pressure explains this trend. The cluster population of dusty red galaxies seems to be particularly influenced by ram-pressure stripping. We measure a reduced gas extent, higher bulge-to-total ratios and lower B-band luminosities (at given mass) for this galaxy type. This fits into a transformation scenario where dusty red galaxies are an intermediate phase and during which field spiral galaxies fall into a cluster

  7. Predicting availability functions in time-dependent complex systems with SAEDES simulation algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Faulin, Javier [Department of Statistics and Operations Research, Los Magnolios Building, First Floor, Campus Arrosadia, Public University of Navarre, 31006 Pamplona, Navarre (Spain)], E-mail: javier.faulin@unavarra.es; Juan, Angel A. [Department of Applied Mathematics I, Av. Doctor Maranon 44-50, Technical University of Catalonia, 08028 Barcelona (Spain)], E-mail: angel.alejandro.juan@upc.edu; Serrat, Carles [Department of Applied Mathematics I, Av. Doctor Maranon 44-50, Technical University of Catalonia, 08028 Barcelona (Spain)], E-mail: carles.serrat@upc.edu; Bargueno, Vicente [Department of Applied Mathematics I, ETS Ingenieros Industriales, Universidad Nacional de Educacion a Distancia, 28080 Madrid (Spain)], E-mail: vbargueno@ind.uned.es

    2008-11-15

    In this paper, we propose the use of discrete-event simulation (DES) as an efficient methodology to obtain estimates of both survival and availability functions in time-dependent real systems-such as telecommunication networks or distributed computer systems. We discuss the use of DES in reliability and availability studies, not only as an alternative to the use of analytical and probabilistic methods, but also as a complementary way to: (i) achieve a better understanding of the system internal behavior and (ii) find out the relevance of each component under reliability/availability considerations. Specifically, this paper describes a general methodology and two DES algorithms, called SAEDES, which can be used to analyze a wide range of time-dependent complex systems, including those presenting multiple states, dependencies among failure/repair times or non-perfect maintenance policies. These algorithms can provide valuable information, specially during the design stages, where different scenarios can be compared in order to select a system design offering adequate reliability and availability levels. Two case studies are discussed, using a C/C++ implementation of the SAEDES algorithms, to show some potential applications of our approach.

  8. Predicting availability functions in time-dependent complex systems with SAEDES simulation algorithms

    International Nuclear Information System (INIS)

    In this paper, we propose the use of discrete-event simulation (DES) as an efficient methodology to obtain estimates of both survival and availability functions in time-dependent real systems-such as telecommunication networks or distributed computer systems. We discuss the use of DES in reliability and availability studies, not only as an alternative to the use of analytical and probabilistic methods, but also as a complementary way to: (i) achieve a better understanding of the system internal behavior and (ii) find out the relevance of each component under reliability/availability considerations. Specifically, this paper describes a general methodology and two DES algorithms, called SAEDES, which can be used to analyze a wide range of time-dependent complex systems, including those presenting multiple states, dependencies among failure/repair times or non-perfect maintenance policies. These algorithms can provide valuable information, specially during the design stages, where different scenarios can be compared in order to select a system design offering adequate reliability and availability levels. Two case studies are discussed, using a C/C++ implementation of the SAEDES algorithms, to show some potential applications of our approach

  9. Evidence for an accretion origin for the outer halo globular cluster system of M31

    CERN Document Server

    Mackey, Dougal; Ferguson, Annette; Irwin, Mike; Tanvir, Nial; McConnachie, Alan; Ibata, Rodrigo; Chapman, Scott; Lewis, Geraint

    2010-01-01

    We use a sample of newly-discovered globular clusters from the Pan-Andromeda Archaeological Survey (PAndAS) in combination with previously-catalogued objects to map the spatial distribution of globular clusters in the M31 halo. At projected radii beyond ~30 kpc, where large coherent stellar streams are readily distinguished in the field, there is a striking correlation between these features and the positions of the globular clusters. Adopting a simple Monte Carlo approach, we test the significance of this association by computing the probability that it could be due to the chance alignment of globular clusters smoothly distributed in the M31 halo. We find the likelihood of this possibility is low, below 1%, and conclude that the observed spatial coincidence between globular clusters and multiple tidal debris streams in the outer halo of M31 reflects a genuine physical association. Our results imply that the majority of the remote globular cluster system of M31 has been assembled as a consequence of the accre...

  10. Clustering and Recurring Anomaly Identification: Recurring Anomaly Detection System (ReADS)

    Science.gov (United States)

    McIntosh, Dawn

    2006-01-01

    This viewgraph presentation reviews the Recurring Anomaly Detection System (ReADS). The Recurring Anomaly Detection System is a tool to analyze text reports, such as aviation reports and maintenance records: (1) Text clustering algorithms group large quantities of reports and documents; Reduces human error and fatigue (2) Identifies interconnected reports; Automates the discovery of possible recurring anomalies; (3) Provides a visualization of the clusters and recurring anomalies We have illustrated our techniques on data from Shuttle and ISS discrepancy reports, as well as ASRS data. ReADS has been integrated with a secure online search

  11. Devices for on-site maintenance allows an increased availability of supplies of orbital welding systems

    International Nuclear Information System (INIS)

    Until now, energy supplies of orbital welding systems had to be shipped for maintenance. As described in this article, technological advances like portable calibration units allow the owners of such systems to perform themselves maintenance operations. On-site calibration results in a reduction of costs and off-site maintenance, therefore in an increased availability. The article describes the main functions of these portable calibration units which are used to calibrate welding critical variables

  12. Indolent systemic mastocytosis: a case and review of the current available treatment options

    OpenAIRE

    Lee, Yvonne; Wood, Peter; Soyer, H. Peter

    2013-01-01

    Mastocytosis denotes a heterogeneous group of disorders characterized by abnormal growth and accumulation of mast cells. Cutaneous mastocytosis is characterized by skin-limited disease and is the most common subtype. Systemic mastocytosis has extracutaneous organ involvement with variable symptomatology and prognosis. Clinical manifestations are secondary to mediator release or direct organ infiltration of mast cells. Current available treatment for systemic mastocytosis is non-curative with ...

  13. Patterns for election of active computing nodes in high availability distributed data acquisition systems

    International Nuclear Information System (INIS)

    Computer based systems for power plant and research reactors are expected to have high availability. Redundancy is a common approach to improve the availability of a system. In redundant configuration the challenge is to select one node as active, and in case of failure of current active node provide automatic fast switchover by electing another node to function as active and restore normal operation. Additional constraints include: exactly one node should be elected as active in an n-way redundant architecture. This paper discusses various high availability configurations developed by Electronics Division and deployed in power and research reactors and patterns followed to elect active nodes of distributed data acquisition systems. The systems are categorized into two: Active/Passive where changeover takes effect only on the failure of Active node, and Active/Active, where changeover is effective in alternate cycles. A novel concept of priority driven state based Active (Master) node election pattern is described for Active/Passive systems which allows multiple redundancy and dynamic election of single master. The paper also discusses the Active/Active pattern, which uncovers failure early by activating all the nodes alternatively in a redundant system. This pattern can be extended to multiple redundant nodes. (author)

  14. Clustering of galaxies near damped Lyman-alpha systems with (z) = 2.6

    Science.gov (United States)

    Wolfe, A. M

    1993-01-01

    The galaxy two-point correlation function, xi, at (z) = 2.6 is determined by comparing the number of Ly-alpha-emitting galaxies in narrowband CCD fields selected for the presence of damped L-alpha absorption to their number in randomly selected control fields. Comparisons between the presented determination of (xi), a density-weighted volume average of xi, and model predictions for (xi) at large redshifts show that models in which the clustering pattern is fixed in proper coordinates are highly unlikely, while better agreement is obtained if the clustering pattern is fixed in comoving coordinates. Therefore, clustering of Ly-alpha-emitting galaxies around damped Ly-alpha systems at large redshifts is strong. It is concluded that the faint blue galaxies are drawn from a parent population different from normal galaxies, the presumed offspring of damped Ly-alpha systems.

  15. Hybrid systems for virtual screening: interest of fuzzy clustering applied to olfaction.

    Science.gov (United States)

    Ros, F; Audouze, K; Pintore, M; Chrétien, J R

    2000-01-01

    Kohonen neural networks, also known as Self Organizing Map (SOM), offer a useful 2D representation of the compound distribution inside a large chemical database. This distribution results from the compound organization in a molecular diversity hyperspace derived from a large set of molecular descriptors. Fuzzy techniques based on the "concept of partial truth" reveal to be also a valuable tool for the direct exploitation of chemical databases or SOM. In such cases a fuzzy clustering algorithm is used. In this paper, a complete hybrid system, combining SOM and fuzzy clustering, is applied. As example, a series of olfactory compounds was selected. The complexity of such information is that a same compound may exhibit different odors. It is shown how fuzzy logic helps to have a better understanding of the organization of the compounds. These hybrid systems, using simultaneously SOM and fuzzy clustering, are foreseen as powerful tools for "virtual pre-screening". PMID:10969876

  16. System Verification Through Reliability, Availability, Maintainability (RAM) Analysis & Technology Readiness Levels (TRLs)

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel Ohene Opare, Jr.; Charles V. Park

    2011-06-01

    The Next Generation Nuclear Plant (NGNP) Project, managed by the Idaho National Laboratory (INL), is authored by the Energy Policy Act of 2005, to research, develop, design, construct, and operate a prototype fourth generation nuclear reactor to meet the needs of the 21st Century. A section in this document proposes that the NGNP will provide heat for process heat applications. As with all large projects developing and deploying new technologies, the NGNP is expected to meet high performance and availability targets relative to current state of the art systems and technology. One requirement for the NGNP is to provide heat for the generation of hydrogen for large scale productions and this process heat application is required to be at least 90% or more available relative to other technologies currently on the market. To reach this goal, a RAM Roadmap was developed highlighting the actions to be taken to ensure that various milestones in system development and maturation concurrently meet required availability requirements. Integral to the RAM Roadmap was the use of a RAM analytical/simulation tool which was used to estimate the availability of the system when deployed based on current design configuration and the maturation level of the system.

  17. Economic Designing of PV/FC/Wind Hybrid System Considering Components Availability

    Directory of Open Access Journals (Sweden)

    Saber Arabi Nowdeh

    2013-09-01

    Full Text Available This paper presents an Optimization Sizing of a stand-alone PV/FC/Wind Hybrid System (PFWHS to optimize the sizes of components of PFWHS. Based on PSO algorithm, one optimal sizing method was developed to determine the optimal configuration of system that can achieve the load required power supply probability (Reliability with a minimum overall cost of energy (OCE.PFW HS costs involve investments, operation and maintenance as well as loss of load costs. The applied wind and radiation datasets belong to northwest region (Jolfa, latitude: 38_56, longitude: 45_37, altitude: 710, m of Iran. In this paper the impact of availability of PFWHS components is investigated on optimal sizing. So, to investigating the impact of component availability rate on PFWHS costs and reliability due to failure and repair rate of PFW HScomponents and uncertainty in wind speed and solar irradiance, two scenarios are considered. In first scenario the availability of all components is considered 1 and in second scenario isn’t considered 1 because of failure and repair rate of components and uncertainty in wind speed and solar irradiance. Obtained results prove that while the overall cost of energy is optimized, the reliability indices are within a satisfactory bound with regard to the reliability standards. Also the results indicate that considering complete availability of components causes more reliability rate, so to achieve the actual behavior of PFW HS, the rate of components availability must be considered in suitable insight to designer for supply the load.

  18. Installation of secure, always available wireless LAN systems as a component of the hospital communication infrastructure.

    Science.gov (United States)

    Hanada, Eisuke; Kudou, Takato; Tsumoto, Shusaku

    2013-06-01

    Wireless technologies as part of the data communication infrastructure of modern hospitals are being rapidly introduced. Even though there are concerns about problems associated with wireless communication security, the demand is remarkably large. In addition, insuring that the network is always available is important. Herein, we discuss security countermeasures and points to insure availability that must be taken to insure safe hospital/business use of wireless LAN systems, referring to the procedures introduced at Shimane University Hospital. Security countermeasures differ according to their purpose, such as for preventing illegal use or insuring availability, both of which are discussed. It is our hope that this information will assist others in their efforts to insure safe implementation of wireless LAN systems, especially in hospitals where they have the potential to greatly improve information sharing and patient safety. PMID:23519703

  19. PHONETIC CLASSIFICATION BY ADAPTIVE NETWORK BASED FUZZY INFERENCE SYSTEM AND SUBTRACTIVE CLUSTERING

    Directory of Open Access Journals (Sweden)

    Samiya Silarbi

    2014-09-01

    Full Text Available This paper presents the application of Adaptive Network Based Fuzzy Inference System ANFIS on speech recognition. The primary tasks of fuzzy modeling are structure identification and parameter optimization, the former determines the numbers of membership functions and fuzzy if-then rules while the latter identifies a feasible set of parameters under the given structure. However, the increase of input dimension, rule numbers will have an exponential growth and there will cause problem of “rule disaster”. Thus, determination of an appropriate structure becomes an important issue where subtractive clustering is applied to define an optimal initial structure and obtain small number of rules. The appropriate learning algorithm is performed on TIMIT speech database supervised type, a pre-processing of the acoustic signal and extracting the coefficients MFCCs parameters relevant to the recognition system. Finally, hybrid learning combines the gradient decent and least square estimation LSE of parameters network. The results obtained show the effectiveness of the method in terms of recognition rate and number of fuzzy rules generated.

  20. Cluster self-organization of silicate and germanate systems: Invariant suprapolyhedral cluster precursors and self-assembly of the crystal structures of Li,TR silicates (germanates)

    International Nuclear Information System (INIS)

    The initial stages of formation of suprapolyhedral clusters (containing polyhedra of different types) in an evolving chemical system are considered. The suprapolyhedral clusters of the chain and cyclic types are used for modeling two-dimensional periodic structures. The developed model is used to search for cluster precursors in the structures of Li,TR silicates (germanates) of the known structure types. The complete threedimensional reconstruction of the self-assembly of Li,TR silicates (germanates) is performed using computer methods (with the TOPOS program package) according to the following scheme: cluster precursor → primary chain → microlayer → microframework (supraprecursor) → ... framework. Two types of invariant cyclic cluster precursors composed of the TR polyhedra linked by tetrahedra and the TR polyhedra joined by diorthotetrahedra are identified in five and two structures, respectively. It is revealed that the lithium atoms are located at the centers of all clusters. New types of two-dimensional nets with a hierarchical structure formed as a result of the packing of cyclic four-, six-, and eight-node clusters are described.

  1. A Rich Globular Cluster System in Dragonfly 17: Are Ultra-Diffuse Galaxies Pure Stellar Halos?

    CERN Document Server

    Peng, Eric W

    2016-01-01

    Observations of nearby galaxy clusters at low surface brightness have identified galaxies with low luminosities, but sizes as large as L* galaxies, leading them to be dubbed "ultra-diffuse galaxies" (UDGs). The survival of UDGs in dense environments like the Coma cluster suggests that UDGs could reside in much more massive dark halos. We report the detection of a substantial population of globular clusters (GCs) around a Coma UDG, Dragonfly 17 (DF17). We find that DF17 has a high GC specific frequency of S_N=26+/-13. The GC system is extended, with an effective radius of 12"+/-2", or 5.6+/-0.9 kpc at Coma distance, 70% larger than the galaxy itself. We also estimate the mean of the GC luminosity function to infer a distance of 97 (+17/-14) Mpc, providing redshift-independent confirmation that one of these UDGs is in the Coma cluster. The presence of a rich GC system in DF17 indicates that, despite its low stellar density, star formation was intense enough to form many massive star clusters. If DF17's ratio of...

  2. Maintenance grouping for multi-component systems with availability constraints and limited maintenance teams

    International Nuclear Information System (INIS)

    The paper deals with a maintenance grouping approach for multi-component systems whose components are connected in series. The considered systems are required to serve a sequence of missions with limited breaks/stoppage durations while maintenance teams (repairmen) are limited and may vary over time. The optimization of the maintenance grouping decision for such multi-component systems leads to a NP-complete problem. The aim of the paper is to propose and to optimize a dynamic maintenance decision rule on a rolling horizon. The heuristic optimization scheme for the maintenance decision is developed by implementing two optimization algorithms (genetic algorithm and MULTIFIT) to find an optimal maintenance planning under both availability and limited repairmen constraints. Thanks to the proposed maintenance approach, impacts of availability constraints or/and limited maintenance teams on the maintenance planning and grouping are highlighted. In addition, the proposed grouping approach allows also updating online the maintenance planning in dynamic contexts such as the change of required availability level and/or the change of repairmen over time. A numerical example of a 20-component system is introduced to illustrate the use and the advantages of the proposed approach in the maintenance optimization framework. - Highlights: • A dynamic maintenance grouping strategy is proposed for multi-component systems. • A grouping approach based on rolling horizon, GA and MULIFIT algorithms is proposed. • Impacts of availability and/or limited repairmen constraints are highlighted. • An optimal planning under availability and/or limited repairmen constraints is given. • The maintenance planning can be dynamically updated in the presence of dynamic contexts

  3. Socio-Cultural Dimensions of Cluster vs. Single Home Photovoltaic Solar Energy Systems in Rural Nepal

    Directory of Open Access Journals (Sweden)

    Kimber Haddix McKay

    2010-02-01

    Full Text Available This paper analyzes the socio-cultural dimensions of obstacles facing solar photovoltaic projects in two villages in rural Nepal. The study was conducted in Humla District, Nepal, one of the most remote and impoverished regions of the country. There are no roads in the district, homes lack running water and villagers’ health suffers from high levels of indoor air pollution from open cooking/heating fires and the smoky torches traditionally burned for light. The introduction of solar energy is important to these villagers, as it removes one major source of indoor air pollution from homes and provides brighter light than the traditional torches. Solar energy is preferable in many villages in the region due to the lack of suitable streams or rivers for micro-hydroelectric projects. In the villages under study in this paper, in-home solar electricity is a novel and recent innovation, and was installed within the last three years in two different geo-spatial styles, depending upon the configuration of homes in the village. In some villages, houses are grouped together, while in others households are widely dispersed. In the former, solar photovoltaic systems were installed in a “cluster” fashion with multiple homes utilizing power from a central battery store under the control of the householder storing the battery bank. In villages with widely spaced households, a single home system was used so that each home had a separate solar photovoltaic array, wiring system and battery bank. It became clear that the cluster system was the sensible choice due to the geographic layout of certain villages, but this put people into management groups that did not always work well due to caste or other differences. This paper describes the two systems and their management and usage costs and benefits from the perspective of the villagers themselves.

  4. Isolated ellipticals and their globular cluster systems. III. NGC 2271, NGC 2865, NGC 3962, NGC 4240, and IC 4889

    Science.gov (United States)

    Salinas, R.; Alabi, A.; Richtler, T.; Lane, R. R.

    2015-05-01

    As tracers of star formation, galaxy assembly, and mass distribution, globular clusters have provided important clues to our understanding of early-type galaxies. But their study has been mostly constrained to galaxy groups and clusters where early-type galaxies dominate, leaving the properties of the globular cluster systems (GCSs) of isolated ellipticals as a mostly uncharted territory. We present Gemini-South/GMOS g'i' observations of five isolated elliptical galaxies: NGC 3962, NGC 2865, IC 4889, NGC 2271, and NGC 4240. Photometry of their GCSs reveals clear color bimodality in three of them, but remains inconclusive for the other two. All the studied GCSs are rather poor with a mean specific frequency SN ~ 1.5, independently of the parent galaxy luminosity. Considering information from previous work as well, it is clear that bimodality and especially the presence of a significant, even dominant, population of blue clusters occurs at even the most isolated systems, which casts doubts on a possible accreted origin of metal-poor clusters, as suggested by some models. Additionally, we discuss the possible existence of ultra-compact dwarfs around the isolated elliptical NGC 3962. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).Globular cluster photometry is available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A59Appendices are available in

  5. Efficiency in Cluster Database Systems - Dynamic and Workload-Aware Scaling and Allocation

    OpenAIRE

    Rabl, Tilmann

    2011-01-01

    Database systems have been vital in all forms of data processing for a long time. In recent years, the amount of processed data has been growing dramatically, even in small projects. Nevertheless, database management systems tend to be static in terms of size and performance which makes scaling a difficult and expensive task. Because of performance and especially cost advantages more and more installed systems have a shared nothing cluster architecture. Due to the massive parallelism of the h...

  6. A Clustering and SVM Regression Learning-Based Spatiotemporal Fuzzy Logic Controller with Interpretable Structure for Spatially Distributed Systems

    Directory of Open Access Journals (Sweden)

    Xian-xia Zhang

    2012-01-01

    Full Text Available Many industrial processes and physical systems are spatially distributed systems. Recently, a novel 3-D FLC was developed for such systems. The previous study on the 3-D FLC was concentrated on an expert knowledge-based approach. However, in most of situations, we may lack the expert knowledge, while input-output data sets hidden with effective control laws are usually available. Under such circumstance, a data-driven approach could be a very effective way to design the 3-D FLC. In this study, we aim at developing a new 3-D FLC design methodology based on clustering and support vector machine (SVM regression. The design consists of three parts: initial rule generation, rule-base simplification, and parameter learning. Firstly, the initial rules are extracted by a nearest neighborhood clustering algorithm with Frobenius norm as a distance. Secondly, the initial rule-base is simplified by merging similar 3-D fuzzy sets and similar 3-D fuzzy rules based on similarity measure technique. Thirdly, the consequent parameters are learned by a linear SVM regression algorithm. Additionally, the universal approximation capability of the proposed 3-D fuzzy system is discussed. Finally, the control of a catalytic packed-bed reactor is taken as an application to demonstrate the effectiveness of the proposed 3-D FLC design.

  7. Phosphate availability alters architecture and causes changes in hormone sensitivity in the Arabidopsis root system.

    Science.gov (United States)

    López-Bucio, José; Hernández-Abreu, Esmeralda; Sánchez-Calderón, Lenin; Nieto-Jacobo, María Fernanda; Simpson, June; Herrera-Estrella, Luis

    2002-05-01

    The postembryonic developmental program of the plant root system is plastic and allows changes in root architecture to adapt to environmental conditions such as water and nutrient availability. Among essential nutrients, phosphorus (P) often limits plant productivity because of its low mobility in soil. Therefore, the architecture of the root system may determine the capacity of the plant to acquire this nutrient. We studied the effect of P availability on the development of the root system in Arabidopsis. We found that at P-limiting conditions (increase in auxin sensitivity in the roots of P-deprived Arabidopsis seedlings. It was also found that the axr1-3, axr2-1, and axr4-1 Arabidopsis mutants have normal responses to low P availability conditions, whereas the iaa28-1 mutant shows resistance to the stimulatory effects of low P on root hair and lateral root formation. Analysis of ethylene signaling mutants and treatments with 1-aminocyclopropane-1-carboxylic acid showed that ethylene does not promote lateral root formation under P deprivation. These results suggest that in Arabidopsis, auxin sensitivity may play a fundamental role in the modifications of root architecture by P availability. PMID:12011355

  8. System and Propagation Availability Analysis for NASA's Advanced Air Transportation Technologies

    Science.gov (United States)

    Ugweje, Okechukwu C.

    2000-01-01

    This report summarizes the research on the System and Propagation Availability Analysis for NASA's project on Advanced Air Transportation Technologies (AATT). The objectives of the project were to determine the communication systems requirements and architecture, and to investigate the effect of propagation on the transmission of space information. In this report, results from the first year investigation are presented and limitations are highlighted. To study the propagation links, an understanding of the total system architecture is necessary since the links form the major component of the overall architecture. This study was conducted by way of analysis, modeling and simulation on the system communication links. The overall goals was to develop an understanding of the space communication requirements relevant to the AATT project, and then analyze the links taking into consideration system availability under adverse atmospheric weather conditions. This project began with a preliminary study of the end-to-end system architecture by modeling a representative communication system in MATLAB SIMULINK. Based on the defining concepts, the possibility of computer modeling was determined. The investigations continue with the parametric studies of the communication system architecture. These studies were also carried out with SIMULINK modeling and simulation. After a series of modifications, two end-to-end communication links were identified as the most probable models for the communication architecture. Link budget calculations were then performed in MATHCAD and MATLAB for the identified communication scenarios. A remarkable outcome of this project is the development of a graphic user interface (GUI) program for the computation of the link budget parameters in real time. Using this program, one can interactively compute the link budget requirements after supplying a few necessary parameters. It provides a framework for the eventual automation of several computations

  9. Mod-2 wind turbine system cluster research test program. Volume 1: Initial plan E-1290

    Science.gov (United States)

    Gordon, L. H.

    1982-01-01

    Upon completion of the design and development of three Mod-2 wind turbines, a series of research experiments are planned to gather data on and evaluate the performance, environmental effects, and operation of a cluster as well as a single, large multimegawatt wind turbine. Information on the program objectives, a Mod-2 system description, a planned schedule, organizational roles, and responsibilities, is included.

  10. Low-energy scattering in four nucleon systems. Method of Cluster Reduction

    OpenAIRE

    Yakovlev, S. L.; Filikhin, I. N.

    1998-01-01

    A method using an expansion of the four-body Yakubovsky wave function components onto the basis of the Faddeev-equation solutions for the two-cluster sub-Hamiltonian eigenfunctions is exploited for computations of low-energy scattering parameters in four nucleon systems. Results of calculations of low-energy scattering parameters in $n-{^3}$H, $n-{^3}$He are presented.

  11. Improving Recommendations in Tag-based Systems with Spectral Clustering of Tag Neighbors

    DEFF Research Database (Denmark)

    Pan, Rong; Xu, Guandong; Dolog, Peter

    2012-01-01

    Tag as a useful metadata reflects the collaborative and conceptual features of documents in social collaborative annotation systems. In this paper, we propose a collaborative approach for expanding tag neighbors and investigate the spectral clustering algorithm to filter out noisy tag neighbors i...

  12. Cluster synchronization in a network of non-identical dynamic systems

    International Nuclear Information System (INIS)

    Dynamic systems is studied in this paper, using two-cluster synchronization for detailed analysis and discussion. The results show that the common intercluster coupling condition is not always needed for the diffusively coupled network. Several sufficient conditions are obtained by using the Schur unitary triangularization theorem, which extends previous results. Some numerical examples are presented for illustration. (general)

  13. Colour-singlet clusters in systems composed of six quarks

    OpenAIRE

    Mickevicius, S.; Kamuntavicius, G. P.

    2003-01-01

    We present an investigation of six quarks system kinematics, independent on quark-quark interactions. There has been created and investigated basis of six quarks antisymmetrical and translationally invariant functions, applying formalism with spin, isospin, and color degrees of freedom and many-particle harmonic oscillator (HO) functions, dependent on Jacobian variables. We have also investigated expansions of realistic wave-functions in this basis. There are given analytical expressions for ...

  14. An Intrusion Detection System Based on Multi-Level Clustering for Hierarchical Wireless Sensor Networks.

    Science.gov (United States)

    Butun, Ismail; Ra, In-Ho; Sankar, Ravi

    2015-01-01

    In this work, an intrusion detection system (IDS) framework based on multi-level clustering for hierarchical wireless sensor networks is proposed. The framework employs two types of intrusion detection approaches: (1) "downward-IDS (D-IDS)" to detect the abnormal behavior (intrusion) of the subordinate (member) nodes; and (2) "upward-IDS (U-IDS)" to detect the abnormal behavior of the cluster heads. By using analytical calculations, the optimum parameters for the D-IDS (number of maximum hops) and U-IDS (monitoring group size) of the framework are evaluated and presented. PMID:26593915

  15. An Intrusion Detection System Based on Multi-Level Clustering for Hierarchical Wireless Sensor Networks

    OpenAIRE

    Ismail Butun; In-Ho Ra; Ravi Sankar

    2015-01-01

    In this work, an intrusion detection system (IDS) framework based on multi-level clustering for hierarchical wireless sensor networks is proposed. The framework employs two types of intrusion detection approaches: (1) “downward-IDS (D-IDS)” to detect the abnormal behavior (intrusion) of the subordinate (member) nodes; and (2) “upward-IDS (U-IDS)” to detect the abnormal behavior of the cluster heads. By using analytical calculations, the optimum parameters for the D-IDS (number of maximum hops...

  16. A scalable and practical one-pass clustering algorithm for recommender system

    Science.gov (United States)

    Khalid, Asra; Ghazanfar, Mustansar Ali; Azam, Awais; Alahmari, Saad Ali

    2015-12-01

    KMeans clustering-based recommendation algorithms have been proposed claiming to increase the scalability of recommender systems. One potential drawback of these algorithms is that they perform training offline and hence cannot accommodate the incremental updates with the arrival of new data, making them unsuitable for the dynamic environments. From this line of research, a new clustering algorithm called One-Pass is proposed, which is a simple, fast, and accurate. We show empirically that the proposed algorithm outperforms K-Means in terms of recommendation and training time while maintaining a good level of accuracy.

  17. Clustering of tethered satellite system simulation data by an adaptive neuro-fuzzy algorithm

    Science.gov (United States)

    Mitra, Sunanda; Pemmaraju, Surya

    1992-01-01

    Recent developments in neuro-fuzzy systems indicate that the concepts of adaptive pattern recognition, when used to identify appropriate control actions corresponding to clusters of patterns representing system states in dynamic nonlinear control systems, may result in innovative designs. A modular, unsupervised neural network architecture, in which fuzzy learning rules have been embedded is used for on-line identification of similar states. The architecture and control rules involved in Adaptive Fuzzy Leader Clustering (AFLC) allow this system to be incorporated in control systems for identification of system states corresponding to specific control actions. We have used this algorithm to cluster the simulation data of Tethered Satellite System (TSS) to estimate the range of delta voltages necessary to maintain the desired length rate of the tether. The AFLC algorithm is capable of on-line estimation of the appropriate control voltages from the corresponding length error and length rate error without a priori knowledge of their membership functions and familarity with the behavior of the Tethered Satellite System.

  18. Type 3 secretion system cluster 3 is a critical virulence determinant for lung-specific melioidosis.

    Directory of Open Access Journals (Sweden)

    Maria G Gutierrez

    2015-01-01

    Full Text Available Burkholderia pseudomallei, the bacterial agent of melioidosis, causes disease through inhalation of infectious particles, and is classified as a Tier 1 Select Agent. Optical diagnostic imaging has demonstrated that murine respiratory disease models are subject to significant upper respiratory tract (URT colonization. Because human melioidosis is not associated with URT colonization as a prominent presentation, we hypothesized that lung-specific delivery of B. pseudomallei may enhance our ability to study respiratory melioidosis in mice. We compared intranasal and intubation-mediated intratracheal (IMIT instillation of bacteria and found that the absence of URT colonization correlates with an increased bacterial pneumonia and systemic disease progression. Comparison of the LD50 of luminescent B. pseudomallei strain, JW280, in intranasal and IMIT challenges of albino C57BL/6J mice identified a significant decrease in the LD50 using IMIT. We subsequently examined the LD50 of both capsular polysaccharide and Type 3 Secretion System cluster 3 (T3SS3 mutants by IMIT challenge of mice and found that the capsule mutant was attenuated 6.8 fold, while the T3SS3 mutant was attenuated 290 fold, demonstrating that T3SS3 is critical to respiratory melioidosis. Our previously reported intranasal challenge studies, which involve significant URT colonization, did not identify a dissemination defect for capsule mutants; however, we now report that capsule mutants exhibit significantly reduced dissemination from the lung following lung-specific instillation, suggesting that capsule mutants are competent to spread from the URT, but not the lung. We also report that a T3SS3 mutant is defective for dissemination following lung-specific delivery, and also exhibits in vivo growth defects in the lung. These findings highlight the T3SS3 as a critical virulence system for respiratory melioidosis, not only in the lung, but also for subsequent spread beyond the lung using a

  19. Libre Systems: Making Data and Software More Available Through Re-usable Components

    Science.gov (United States)

    Lewis, S.; Lacy, J.; Reed, S.; Truslove, I.; Lopez, L.; McNulty, M.; Wu, H.; Duerr, R. E.

    2011-12-01

    With the amount of stored data increasing at an exponential rate, it is becoming increasingly important for scientists and data managers to find effective ways to allow users to discover and use data effectively. Sharing software tools to assist in this effort is also becoming more vital in making this a reality. The National Snow and Ice Data Center's Libre project is solving this by creating a system of components including an aggregator, which will allow users to find data and services matching specified criteria more easily. While making it flexible enough to ingest metadata from various sources is important, it is also important to make the concepts and actual software components available to others who wish to make their data and services more discoverable and accessible. The Libre system is designed to make this a reality, by componentizing the underlying mechanisms and thus allowing the pieces to be shared and reused by those who need them. These components can then be tailored to meet specific needs, allowing the individual data providers to avoid wasteful duplication of effort, and focus more on making their data available to the world. This componentization would also allow the data providers to replace specific pieces with other software if desired, while still preserving the overall functionality of the system. When finished, the various components of the Libre system will be released to the open source community, facilitating the easy inclusion and modification of the system, and allowing users to discover data and services more easily.

  20. Erosion of Globular Cluster Systems: The Influence of Radial Anisotropy, Central Black Holes and Dynamical Friction

    CERN Document Server

    Brockamp, Michael; Thies, Ingo; Baumgardt, Holger; Kroupa, Pavel

    2014-01-01

    We present the adaptable MUESLI code for investigating dynamics and erosion processes of globular clusters (GCs) in galaxies. MUESLI follows the orbits of individual clusters and applies internal and external dissolution processes to them. Orbit integration is based on the self-consistent field method in combination with a time-transformed leapfrog scheme, allowing us to handle velocity-dependent forces like triaxial dynamical friction. In a first application, the erosion of globular cluster systems (GCSs) in elliptical galaxies is investigated. Observations show that massive ellipticals have rich, radially extended GCSs, while some compact dwarf ellipticals contain no GCs at all. For several representative examples, spanning the full mass scale of observed elliptical galaxies, we quantify the influence of radial anisotropy, galactic density profiles, SMBHs, and dynamical friction on the GC erosion rate. We find that GC number density profiles are centrally flattened in less than a Hubble time, naturally expl...

  1. The shape of the mass distribution in M31 from its globular cluster system

    Science.gov (United States)

    Kent, Stephen M.; Huchra, John P.; Stauffer, John

    1989-01-01

    The velocity dispersion and rotation velocity of the M31 globular cluster system depend on the relative division of mass between the flat disk and a spherically symmetric halo. Using the tensor virial theorem, it is shown in detail how the mass ratio can be constrained. Radial velocities have been collected for 149 globular clusters in M31. With no assumptions about the isotropy of the velocity distribution, the globular cluster kinematics are consistent with the mass distribution inferred by the rotation curve but otherwise place no strong constraints on the relative division of the mass. If the velocity distribution is isotropic, models with the disk mass ranging between 1/2 and 1 times its maximum possible value are marginally favored.

  2. Physical interpretation and theory of existence of cluster structures in lattices of dynamical systems

    International Nuclear Information System (INIS)

    The alternative theory of existence of cluster structures in lattices of dynamical systems (oscillators) is proposed. This theory is based on representation of structures as a result of classical (full) synchronization of structural objects called cluster oscillators (C-oscillators). Different types of C-oscillators, whose number is defined by the geometrical properties of lattices (dimensions and forms) are introduced. The completeness of all types of C-oscillators for lattices of different dimensions is proven. This fact provides a full set of types of cluster structures that can be realized in a given lattice. The solution is derived without the necessity to verify the existence of invariant (cluster) manifolds. The principles of coupling of C-oscillators into the cluster structures and principles of transformations of such structures are described. Having interpreted the processes of structuring in terms of the classical synchronization of C-oscillators, one can solve the problem of fusion of lattices with pre-described properties at the engineering level

  3. Physical interpretation and theory of existence of cluster structures in lattices of dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Verichev, Nikolai N. [Mechanical Engineering Institute, Russian Academy of Sciences, Belinskogo 85, 603024 Nizhny Novgorod (Russian Federation); Verichev, Stanislav N. [Technology Company Schlumberger, Respubliki 59, 625000 Tyumen (Russian Federation); Wiercigroch, Marian [Centre for Applied Dynamics Research, Department of Engineering, University of Aberdeen, King' s College, Aberdeen AB24 3UE, Scotland (United Kingdom)]. E-mail: M.Wiercigroch@eng.abdn.ac.uk

    2007-11-15

    The alternative theory of existence of cluster structures in lattices of dynamical systems (oscillators) is proposed. This theory is based on representation of structures as a result of classical (full) synchronization of structural objects called cluster oscillators (C-oscillators). Different types of C-oscillators, whose number is defined by the geometrical properties of lattices (dimensions and forms) are introduced. The completeness of all types of C-oscillators for lattices of different dimensions is proven. This fact provides a full set of types of cluster structures that can be realized in a given lattice. The solution is derived without the necessity to verify the existence of invariant (cluster) manifolds. The principles of coupling of C-oscillators into the cluster structures and principles of transformations of such structures are described. Having interpreted the processes of structuring in terms of the classical synchronization of C-oscillators, one can solve the problem of fusion of lattices with pre-described properties at the engineering level.

  4. Dietary Crude Lecithin Increases Systemic Availability of Dietary Docosahexaenoic Acid with Combined Intake in Rats

    OpenAIRE

    van Wijk, Nick; Balvers, Martin; Cansev, Mehmet; Maher, Timothy J.; Sijben, John W. C.; Broersen, Laus M.

    2016-01-01

    Crude lecithin, a mixture of mainly phospholipids, potentially helps to increase the systemic availability of dietary omega-3 polyunsaturated fatty acids (n-3 PUFA), such as docosahexaenoic acid (DHA). Nevertheless, no clear data exist on the effects of prolonged combined dietary supplementation of DHA and lecithin on RBC and plasma PUFA levels. In the current experiments, levels of DHA and choline, two dietary ingredients that enhance neuronal membrane formation and function, were determined...

  5. Use of simulation methods in the evaluation of reliability and availability of complex system

    International Nuclear Information System (INIS)

    After a short review of the available standard methods in the reliability field like Boolean algebra for fault tree and the semi-regeneration theory for Markov, this paper shows how the BIAF code based on state description of a system and simulation techique can solve many problems. It also shows how the use of importance sampling and biasing techniques allows us to deal with the rare event problem

  6. Strong clustering of high-redshift Lyman-$\\alpha$ forest absorption systems

    CERN Document Server

    Fernández-Soto, A; Barcons, X; Carswell, R F; Webb, J K; Yahil, A

    1996-01-01

    We use new observations of very weak CIV absorption lines associated with high-redshift Lyman-alpha absorption systems to measure the high-redshift Lyman-alpha line two-point correlation function (TPCF). These very weak CIV absorption lines trace small-scale velocity structure that cannot be resolved by Lyman-alpha absorption lines. We find that (1) high-redshift Lyman-alpha absorption systems with N(HI) > 3.10^14 cm^{-2} are strongly clustered in redshift, (2) previous measurements of the Lyman-alpha line TPCF underestimated the actual clustering of the absorbers due to unresolved blending of overlapping velocity components, (3) the present observations are consistent with the hypothesis that clustering of Lyman-alpha absorption systems extends to lower column densities, but maybe with smaller amplitude in the correlation function, and (4) the observed clustering is broadly compatible with that expected for galaxies at z \\sim 2-3. We interpret these results as suggesting that many or most Lyman-alpha absorbe...

  7. Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

    Institute of Scientific and Technical Information of China (English)

    Maogang HE; Xinzhou SONG; Ying ZHANG; Jiantao ZHANG

    2008-01-01

    A new tandem double-capillary tube refri-geration system for refrigerator-freezers is proposed. A capillary tube was added between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of state was adopted to calculate the thermodynamic properties of the refrigerants, and the available energy analysis of the vapor compression refrigeration cycle was programmed to calculate the thermodynamic perfor-mances of the new and the conventional refrigeration cycle of the refrigerator-freezer. The calculation results show that the available energy efficiency of the conven-tional refrigeration cycle of the refrigerator-freezer is 21.20% and 20.57%, respectively when the refrigerant is R12 and R134a, while that of the double-capillary tube refrigeration cycle of the refrigerator-freezer is 23.97% and 23.44%, respectively. By comparison, the available energy efficiency of the new refrigeration system increases by 13.07% and 13.95%, respectively.

  8. Static security-based available transfer capability using adaptive neuro fuzzy inference system

    Energy Technology Data Exchange (ETDEWEB)

    Venkaiah, C.; Vinod Kumar, D.M.

    2010-07-01

    In a deregulated power system, power transactions between a seller and a buyer can only be scheduled when there is sufficient available transfer capability (ATC). Internet-based, open access same-time information systems (OASIS) provide market participants with ATC information that is continuously updated in real time. Static security-based ATC can be computed for the base case system as well as for the critical line outages of the system. Since critical line outages are based on static security analysis, the computation of static security based ATC using conventional methods is both tedious and time consuming. In this study, static security-based ATC was computed for real-time applications using 3 artificial intelligent methods notably the back propagation algorithm (BPA), the radial basis function (RBF) neural network, and the adaptive neuro fuzzy inference system (ANFIS). An IEEE 24-bus reliability test system (RTS) and 75-bus practical system were used to test these 3 different intelligent methods. The results were compared with the conventional full alternating current (AC) load flow method for different transactions.

  9. WAAS error, integrity and availability modeling for GPS based aircraft landing system

    Science.gov (United States)

    Mu, Guangwei

    From its initial conception to deployment, the Wide Area Augmentation System (WAAS) was hailed as revolutionary for the navigation industry. However, the WAAS deployment effort has suffered significant delays and budget overruns. The reason for these misfortunes lies in the demanding mandates on the performance of the WAAS system. In the long process of getting WAAS commissioned, availability has always been the metric that holds the system back from achieving the promised capability. The inherent tradeoff between integrity and availability is the major reason that the VPL and HPL algorithms need to be improved. The integrity algorithms are well defined in the WAAS Minimum Operational Performance Standards (MOPS). However, our experimental data clearly indicate that the MOPS VPL and HPL algorithms are over-conservative. This lack of compactness from the MOPS introduces unnecessary epochs of the system being unavailable. To improve the system performance, the intuitive approach is through the range/correction domain since these factors can be observed, controlled and manipulated to improve the system performance in individual cases. However, we need a better error model and better understanding of the threat model, i.e. we need to know more about the nature of all error sources and the threats the WAAS faces, which is very difficult to accomplish due to the stochastic natures of these sources. Therefore, it is unlikely that a range/correction domain solution can be applied to a wide range of applications while having significant improvement for the system performance. Besides, it is still subject to the hindrance that the WAAS message structure might need to be changed or adjusted to take advantage of the new development. In this dissertation, a new position domain algorithm is presented to improve the MOPS integrity methodology in hopes of improving the overall system performance. The information needed to do this is already in the WAAS messages. Therefore, this

  10. Achieving High Performance Distributed System: Using Grid, Cluster and Cloud Computing

    OpenAIRE

    Sunil Kr Singh; Kavneet Kaur

    2015-01-01

    To increase the efficiency of any task, we require a system that would provide high performance along with flexibilities and cost efficiencies for user. Distributed computing, as we are all aware, has become very popular over the past decade. Distributed computing has three major types, namely, cluster, grid and cloud. In order to develop a high performance distributed system, we need to utilize all the above mentioned three types of computing. In this paper, we shall first have a...

  11. Clustering as a prerequisite for chimera states in globally coupled systems

    OpenAIRE

    Schmidt, Lennart; Krischer, Katharina

    2014-01-01

    The coexistence of coherently and incoherently oscillating parts in a system of identical oscillators with symmetrical coupling, i.e., a chimera state, is even observable with uniform global coupling. We address the question of the prerequisites for these states to occur in globally coupled systems. By analyzing two different types of chimera states found for nonlinear global coupling, we show that a clustering mechanism to split the ensemble into two groups is needed as a first step. In fact...

  12. Medical imaging environment : a multi-agent system for a computer clustering based multi-display

    OpenAIRE

    Alves, Victor; Marreiros, Filipe; Nelas, Luís; Heymer, Mourvlise; Neves, José

    2007-01-01

    This paper presents a solution to minimize a problem that normally arises from the huge amount of images that a radiologist usually has to interpret. A multi-agent system that implements a multi-display for medical imaging based on computer clustering of normal personal computers is therefore described, as well as the multi-agent architecture that caters for the system evolution. An evaluation study was performed and its results are presented.

  13. Aircraft scanner data availability via the version 0 Information Management System

    Science.gov (United States)

    Mah, G. R.

    1995-01-01

    As part of the Earth Observing System Data and Information System (EOSDIS) development, NASA and other government agencies have developed an operational prototype of the Information Management System (IMS). The IMS provides access to the data archived at the Distributed Active Archive Centers (DAAC's) that allows users to search through metadata describing the (image) data. Criteria based on sensor name or type, date and time, and geographic location are used to search the archive. Graphical representations of coverage and browse images are available to further refine a user's selection. previously, the EROS Data Center (EDC) DAAC had identified the Advanced SOlid-state Array Spectrometer (ASAS), Airborne Visible and infrared Imaging Spectrometer (AVIRIS), NS-001, and Thermal Infrared Multispectral Scanner (TIMS) as precursor data sets similar to those the DAAC will handle in the Earth Observing System era. Currently, the EDC DAAC staff, in cooperation with NASA, has transcribed TIMS, NS-001, and Thematic Mapper Simulation (TMS) data from Ames Research Center and also TIMS data from Stennis Space Center. During the transcription process, the IMS metadata and browse images were created to populate the inventory at the EDC DAAC. These data sets are now available in the IMS and may be requested from the any of the DAAC's via the IMS.

  14. Operation flexibility and availability improvements using BEACON, an advanced core monitoring system

    International Nuclear Information System (INIS)

    In response to utilities needs in improving plant operation flexibility and plant availability, Westinghouse introduced the advanced core monitoring and operational support system, BEACON, two years ago. Since then, the continuous development of the BEACON system has led to significant advances in further reducing utilities Operation and Maintenance (O and M) costs. The development of the BEACON system is made possible by two breakthroughs: 1) advanced numerical method to solve the diffusion equations extremely fast and 2) development of cost effective, state-of-the-art computing system, workstation. This paper presents the numerical scheme used in the neutronic solution and how BEACON uses the core instrumentations to provide the continuous three-dimensional (3D) core power distribution. Once the state of the core is known on a continuous basis, several indirect surveillance and/or Technical Specifications on core power distribution can be relaxed or totally eliminated. Section 1 outlines the numerical scheme used in BEACON for solving the diffusion equations and to provide the 3D continuous power distribution. Section 2 describes the hardware requirements. Section 3 discusses applications of BEACON to improve plant operation flexibility and plant availability. Examples of actual BEACON usage to demonstrate its effectiveness are presented in Section 4 and the paper is closed with a summary of future directions. (author). 4 refs, 6 figs

  15. 40 CFR 142.304 - For which of the regulatory requirements is a small system variance available?

    Science.gov (United States)

    2010-07-01

    ... requirements is a small system variance available? 142.304 Section 142.304 Protection of Environment... REGULATIONS IMPLEMENTATION Variances for Small System General Provisions § 142.304 For which of the regulatory requirements is a small system variance available? (a) A small system variance is not available under...

  16. Implementation of a versatile research data acquisition system using a commercially available medical ultrasound scanner

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Nikolov, Svetoslav Ivanov; Pedersen, Mads Møller;

    2012-01-01

    to give researchers and clinicians the ability to utilize third-party software for data analysis and flexible manipulation of control parameters. Because of the advantages of speed of acquisition and clinical benefit, research projects have successfully used the system to test and implement......This paper describes the design and implementation of a versatile, open-architecture research data acquisition system using a commercially available medical ultrasound scanner. The open architecture will allow researchers and clinicians to rapidly develop applications and move them relatively easy...... to the clinic. The system consists of a standard PC equipped with a camera link and an ultrasound scanner equipped with a research interface. The ultrasound scanner is an easy-to-use imaging device that is capable of generating high-quality images. In addition to supporting the acquisition of multiple data...

  17. A discussion of system reliability and the relative importance of pumps and valves to overall system availability

    Energy Technology Data Exchange (ETDEWEB)

    Poole, A.B. [Oak Ridge National Lab., TN (United States)

    1996-12-01

    An analysis was undertaken to establish preliminary trends for how component aging can effect failure rates for swing check valves, centrifugal pumps and motor operated valves. These failure rate trends were evaluated over time and linear aging rate models established. The failure rate models were then used with classic reliability theories to estimate reliability as a function of operating time. Reliability theory was also used to establish a simple system reliability model. Using the system model, the relative importance of pumps and valves to the overall system reliability were studied. Conclusions were established relative to overall system availability over time and the relative unavailabilities of the various components studied.

  18. Unique mission options available with a megawatt-class nuclear electric propulsion system

    Energy Technology Data Exchange (ETDEWEB)

    Coomes, E.P.; McCauley, L.A.; Christian, J.L.; Gomez, M.A.; Wong, W.A.

    1988-10-01

    The advantages of using electric propulsion systems are well-known in the aerospace community with the most common being its high specific impulse, lower propellant requirements, and lower system mass. But these advantages may not be as important as the overall unique mission options electric propulsion makes possible, especially if the system is powered by a megawatt-class nuclear electric power source. Although the lack of suitable electric power systems has been a major drawback to electric propulsion, recent efforts have shown megawatt-class nuclear electric power systems are feasible and could be available by the turn of the century. Coupling this with the resurgence in interest in free-space electromagnetic transmission of energy and technology developments in this area provide a whole new aspect to the view of electric propulsion. The propulsion system now has a second mission function that may be of more value than the well understood benefits of electric propulsion; that is providing large quantities of prime power in support of a broad spectrum of mission tasks. 30 refs., 9 figs.

  19. Application of genetic algorithms to integrated optimization of safety system availability

    International Nuclear Information System (INIS)

    Experience gained on systems design, operation, and maintenance, with the increasing degree of complexity, and the growth of computational processing capacity, makes it possible the development of integrated optimization techniques, which take into account the interaction of all involved phases in systems operation. However, such a broad approach, which describes in an integrated way, the involved factors, from the conception of the structure to maintenance policies, makes the problem more complex. Generally, the original problem is cast into a simpler one, by imposing some degree of linearity, which allows for a more conventional treatment. The effect of this linear approach is a sensible increase in the number of variables and constraints to be treated. Another shortcoming is related to the fact that as long as the description of some parameters is allowed to undergo modifications, the resulting model becomes less realistic. This paper presents an integrated optimization method of system performance based on genetic algorithms. The aim is to maximize the benefits from operating a simplified system, where different features, like the structure itself, its design, reliability, redundancy allocation, test and maintenance actions scheduling, and costs, are simultaneously taken into account in an integrated way. The availability model treats the original problem without performing any transformation. The set of solutions generated allows a decision-making support for which budgetary and safety constraints must be considered. The results show that the integrated approach used for optimizing the system is much more convenient and should be applied to more complex systems. (author)

  20. The sluggs survey: HST/ACS mosaic imaging of the NGC 3115 globular cluster system

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Romanowsky, Aaron J.; Brodie, Jean P.; Arnold, Jacob A. [University of California Observatories, Santa Cruz, CA 95064 (United States); Strader, Jay [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, MI 48824 (United States); Lin, Dacheng; Irwin, Jimmy A.; Wong, Ka-Wah [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Sivakoff, Gregory R., E-mail: zgjennin@ucsc.edu [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)

    2014-08-01

    We present Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) g and z photometry and half-light radii R {sub h} measurements of 360 globular cluster (GC) candidates around the nearby S0 galaxy NGC 3115. We also include Subaru/Suprime-Cam g, r, and i photometry of 421 additional candidates. The well-established color bimodality of the GC system is obvious in the HST/ACS photometry. We find evidence for a 'blue tilt' in the blue GC subpopulation, wherein the GCs in the blue subpopulation get redder as luminosity increases, indicative of a mass-metallicity relationship. We find a color gradient in both the red and blue subpopulations, with each group of clusters becoming bluer at larger distances from NGC 3115. The gradient is of similar strength in both subpopulations, but is monotonic and more significant for the blue clusters. On average, the blue clusters have ∼10% larger R {sub h} than the red clusters. This average difference is less than is typically observed for early-type galaxies but does match that measured in the literature for the Sombrero Galaxy (M104), suggesting that morphology and inclination may affect the measured size difference between the red and blue clusters. However, the scatter on the R {sub h} measurements is large. We also identify 31 clusters more extended than typical GCs, which we term ultra-compact dwarf (UCD) candidates. Many of these objects are actually considerably fainter than typical UCDs. While it is likely that a significant number will be background contaminants, six of these UCD candidates are spectroscopically confirmed as NGC 3115 members. To explore the prevalence of low-mass X-ray binaries in the GC system, we match our ACS and Suprime-Cam detections to corresponding Chandra X-ray sources. We identify 45 X-ray-GC matches: 16 among the blue subpopulation and 29 among the red subpopulation. These X-ray/GC coincidence fractions are larger than is typical for most GC systems, probably due to the increased

  1. Ants for Document Clustering

    Directory of Open Access Journals (Sweden)

    Priya Vaijayanthi

    2012-03-01

    Full Text Available The usage of computers for mass storage has become mandatory nowadays due to World Wide Web (WWW. This has placed many challenges to the Information Retrieval (IR system. Clustering of documents available improves the efficiency of IR system. The problem of clustering has become a combinatorial optimization problem in IR system due to the exponential growth in information over WWW. In this paper, a hybrid algorithm that combines the basic Ant Colony Optimization with Tabu search has been proposed. The feasibility of the proposed algorithm is tested over a few standard benchmark datasets. The experimental results reveal that the proposed algorithm yields promising quality clusters compared to other ones produced by K-means algorithm.

  2. An Improved Location aided Cluster Based Routing Protocol with Intrusion Detection System in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    S. Mangai

    2011-01-01

    Full Text Available Problem statement: Routing and security are the main challenges for ad hoc networks due to dynamic topology as well as resource constraints. A designed protocol must provide scalable routing with better security. Lack of any central coordination and shared wireless medium makes them more vulnerable to attacks than wired networks. And also resource constraints such as limited energy and size also play an important role in the protocols designed for security. Approach: In this study, Improved Location aided Cluster based Routing Protocol (ILCRP for GPS enabled MANETs was analysed in MANETs with malicious nodes and an Intrusion Detection System was used to increase the packet delivery ratio. ILCRP makes use of location aided routing in the presence of cluster based routing Protocol. Results: Use of location information with security against attacks results in high packet delivery ratio for the cluster based routing protocol. Simulations are performed using NS2 by varying the number of nodes. Conclusion: The results illustrate ILCRP provides higher delivery ratio with IDS.

  3. Ram pressure and dusty red galaxies - key factors in the evolution of the multiple cluster system Abell 901/902

    CERN Document Server

    Bösch, Benjamin; Wolf, Christian; Aragón-Salamanca, Alfonso; Barden, Marco; Gray, Meghan E; Ziegler, Bodo L; Schindler, Sabine; Balogh, Michael

    2012-01-01

    We present spectroscopic observations of 182 disk galaxies (96 in the cluster and 86 in the field environment) in the region of the Abell 901/902 multiple cluster system, which is located at a redshift of $z\\sim 0.165$. The presence of substructures and non-Gaussian redshift distributions indicate that the cluster system is dynamically young and not in a virialized state. We find evidence for two important galaxy populations. \\textit{Morphologically distorted galaxies} are probably subject to increased tidal interactions. They show pronounced rotation curve asymmetries at intermediate cluster-centric radii and low rest-frame peculiar velocities. \\textit{Morphologically undistorted galaxies} show the strongest rotation curve asymmetries at high rest-frame velocities and low cluster-centric radii. Supposedly, this group is strongly affected by ram-pressure stripping due to interaction with the intra-cluster medium. Among the morphologically undistorted galaxies, dusty red galaxies have particularly strong rotat...

  4. Automated detection of clustered microcalcifications on mammograms: CAD system application to MIAS database

    International Nuclear Information System (INIS)

    To investigate the detection performance of our automated detection scheme for clustered microcalcifications on mammograms, we applied our computer-aided diagnosis (CAD) system to the database of the Mammographic Image Analysis Society (MIAS) in the UK. Forty-three mammograms from this database were used in this study. In our scheme, the breast regions were firstly extracted by determining the skinline. Histograms of the original images were used to extract the high-density area within the breast region as the segmentation from the fatty area around the skinline. Then the contrast correction technique was employed. Gradient vectors of the image density were calculated on the contrast corrected images. To extract the specific features of the pattern of the microcalcifications, triple-ring filter analysis was employed. A variable-ring filter was used for more accurate detection after the triple-ring filter. The features of the detected candidate areas were then characterized by feature analysis. The areas which satisfied the characteristics and specific terms were classified and displayed as clusters. As a result, the sensitivity was 95.8% with the false-positive rate at 1.8 clusters per image. This demonstrates that the automated detection of clustered microcalcifications in our CAD system is reliable as an aid to radiologists. (author)

  5. A variational cluster approach to strongly correlated quantum systems out of equilibrium

    International Nuclear Information System (INIS)

    Full text: The theoretical understanding of the non-equilibrium behaviour of strongly correlated quantum many body systems is a long standing challenge, which has become increasingly relevant with the progress made in the fields of molecular-and nano- electronics, spintronics, spectroscopy or quantum optics and simulation. We report on the development of non-equilibrium cluster perturbation theory, and its variational improvement, the non-equilibrium variational cluster approach for steady-state situations. The non-equilibrium extensions of the well established cluster perturbation theory and the variational cluster approach are based on the Keldysh Green’s function method which allows, in this case, accessing single particle dynamic quantities on the whole complex plane. These flexible and versatile techniques can in principle be applied to any fermionic / bosonic lattice Hamiltonian, including multiband and multi-impurity system. Within this framework it is possible to work in the thermodynamic limit and therefore exchange particles with a bath and/or dissipate energy. We present results for the steady-state of molecular / nano devices under bias including the effects of electron-electron interactions. (author)

  6. Materiel availability modeling and analysis for a complex army weapon system.

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, David W. (US Army); Anderson, Dennis James; Martin, Jeffrey A. (US Army); Hoffman, Matthew J.

    2010-10-01

    Materiel availability (A{sub m}) is a new US Department of Defense Key Performance Parameter (KPP) implemented through a mandatory Sustainment Metric consisting of an Availability KPP and two supporting Key System Attributes (KSAs), materiel reliability and ownership cost. Sandia National Laboratories (Sandia), in conjunction with several US Army organizations, developed the analytical foundation, assumptions, and brigade-level modeling approach to support lifecycle, fleet-wide A{sub m} modeling and analysis of a complex Army weapon system. Like operational availability (A{sub o}), A{sub m} is dependent on reliability, but A{sub m} is also affected by other factors that do not impact A{sub o}. The largest influences on A{sub m} are technology insertion and reset downtimes. A{sub m} is a different metric from A{sub o}. Whereas A{sub o} is an operational measure, A{sub m} is more of a programmatic measure that spans a much larger timeframe, additional sources of downtime, and additional sources of unscheduled maintenance.

  7. Behavioural activation system sensitivity is associated with cerebral μ-opioid receptor availability.

    Science.gov (United States)

    Karjalainen, Tomi; Tuominen, Lauri; Manninen, Sandra; Kalliokoski, Kari K; Nuutila, Pirjo; Jääskeläinen, Iiro P; Hari, Riitta; Sams, Mikko; Nummenmaa, Lauri

    2016-08-01

    The reinforcement-sensitivity theory proposes that behavioural activation and inhibition systems (BAS and BIS, respectively) guide approach and avoidance behaviour in potentially rewarding and punishing situations. Their baseline activity presumably explains individual differences in behavioural dispositions when a person encounters signals of reward and harm. Yet, neurochemical bases of BAS and BIS have remained poorly understood. Here we used in vivo positron emission tomography with a µ-opioid receptor (MOR) specific ligand [(11)C]carfentanil to test whether individual differences in MOR availability would be associated with BAS or BIS. We scanned 49 healthy subjects and measured their BAS and BIS sensitivities using the BIS/BAS scales. BAS but not BIS sensitivity was positively associated with MOR availability in frontal cortex, amygdala, ventral striatum, brainstem, cingulate cortex and insula. Strongest associations were observed for the BAS subscale 'Fun Seeking'. Our results suggest that endogenous opioid system underlies BAS, and that differences in MOR availability could explain inter-individual differences in reward seeking behaviour. PMID:27053768

  8. Cluster beam sources. Part 1. Methods of cluster beams generation

    Directory of Open Access Journals (Sweden)

    A.Ju. Karpenko

    2012-10-01

    Full Text Available The short review on cluster beams generation is proposed. The basic types of cluster sources are considered and the processes leading to cluster formation are analyzed. The parameters, that affects the work of cluster sources are presented.

  9. Retrieval with Clustering in a Case-Based Reasoning System for Radiotherapy Treatment Planning

    Science.gov (United States)

    Khussainova, Gulmira; Petrovic, Sanja; Jagannathan, Rupa

    2015-05-01

    Radiotherapy treatment planning aims to deliver a sufficient radiation dose to cancerous tumour cells while sparing healthy organs in the tumour surrounding area. This is a trial and error process highly dependent on the medical staff's experience and knowledge. Case-Based Reasoning (CBR) is an artificial intelligence tool that uses past experiences to solve new problems. A CBR system has been developed to facilitate radiotherapy treatment planning for brain cancer. Given a new patient case the existing CBR system retrieves a similar case from an archive of successfully treated patient cases with the suggested treatment plan. The next step requires adaptation of the retrieved treatment plan to meet the specific demands of the new case. The CBR system was tested by medical physicists for the new patient cases. It was discovered that some of the retrieved cases were not suitable and could not be adapted for the new cases. This motivated us to revise the retrieval mechanism of the existing CBR system by adding a clustering stage that clusters cases based on their tumour positions. A number of well-known clustering methods were investigated and employed in the retrieval mechanism. Results using real world brain cancer patient cases have shown that the success rate of the new CBR retrieval is higher than that of the original system.

  10. Sales Forecasting Based on ERP System through Delphi, fuzzy Clustering and Back-Propagation Neural Networks with adaptive learning rate

    Directory of Open Access Journals (Sweden)

    Attariuas Hicham

    2012-11-01

    Full Text Available In recent years, there has been a strong tendency by companies to use centralized management systems like Enterprise resource planning (ERP. ERP systems offer a comprehensive and simplified process managements and extensive functional coverage. Sales management module is an important element business management of ERP. This paper describes an intelligent hybrid sales forecasting system ERP-FCBPN sales forecast based on architecture of ERP through Delphi, fuzzy clustering and Back-propagation (BP Neural Networks with adaptive learning rate (FCBPN. The proposed approach is composed of three stages: (1 Stage of data collection: Data collection will be implemented from the fields (attributes existing at the interfaces (Tables the database of the ERP. Collection of Key factors that influence sales be made using the Delphi method; (2 Stage of Data preprocessing: Winter Exponential Smoothing method will be utilized to take the trend effect into consideration. (3 Stage of learning by FCBPN: We use hybrid sales forecasting system based on Delphi, fuzzy clustering and Back-propagation (BP Neural Networks with adaptive learning rate (FCBPN. The data for this study come from an industrial company that manufactures packaging. Experimental results show that the proposed model outperforms the previous and traditional approaches. Therefore, it is a very promising solution for industrial forecasting.

  11. Chaos control of ferroresonance system based on RBF-maximum entropy clustering algorithm

    International Nuclear Information System (INIS)

    With regards to the ferroresonance overvoltage of neutral grounded power system, a maximum-entropy learning algorithm based on radial basis function neural networks is used to control the chaotic system. The algorithm optimizes the object function to derive learning rule of central vectors, and uses the clustering function of network hidden layers. It improves the regression and learning ability of neural networks. The numerical experiment of ferroresonance system testifies the effectiveness and feasibility of using the algorithm to control chaos in neutral grounded system

  12. Summary and evaluation of available hydraulic property data for the Hanford Site unconfined aquifer system

    International Nuclear Information System (INIS)

    Improving the hydrologic characterization of the Hanford Site unconfined aquifer system is one of the objectives of the Hanford Site Ground-Water Surveillance Project. To help meet this objective, hydraulic property data available for the aquifer have been compiled, mainly from reports published over the past 40 years. Most of the available hydraulic property estimates are based on constant-rate pumping tests of wells. Slug tests have also been conducted at some wells and analyzed to determine hydraulic properties. Other methods that have been used to estimate hydraulic properties of the unconfined aquifer are observations of water-level changes in response to river stage, analysis of ground-water mound formation, tracer tests, and inverse groundwater flow models

  13. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Benacquista Matthew J.

    2006-02-01

    Full Text Available The galactic population of globular clusters are old, dense star systems, with a typical cluster containing 10^4 - 10^7 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss the theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution which lead to relativistic binaries, and current and possible future observational evidence for this population. Globular cluster evolution will focus on the properties that boost the production of hard binary systems and on the tidal interactions of the galaxy with the cluster, which tend to alter the structure of the globular cluster with time. The interaction of the components of hard binary systems alters the evolution of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker-Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  14. Building a highly available and intrusion tolerant database security and protection system ( DSPS)

    Institute of Scientific and Technical Information of China (English)

    蔡亮; 杨小虎; 董金祥

    2003-01-01

    Database Security and Protection System (DSPS) is a security platform for fighting malicious DBMS. The security and performance are critical to DSPS. The authors suggested a key management scheme by combining the server group structure to improve availability and the key distribution structure needed by proactive security. This paper detailed the implementation of proactive security in DSPS. After thorough performane analysis, the authors concluded that the performance difference between the replicated mechanism and proactive mechanism becomes smaller and smaller with increasing number of concurrent connections ; and that proactive security is very useful and practical for large, critical applications.

  15. Procedures for controlling the risks of reliability, safety, and availability of technical systems

    International Nuclear Information System (INIS)

    The reference book covers four sections. Apart from the fundamental aspects of the reliability problem, of risk and safety and the relevant criteria with regard to reliability, the material presented explains reliability in terms of maintenance, logistics and availability, and presents procedures for reliability assessment and determination of factors influencing the reliability, together with suggestions for systems technical integration. The reliability assessment consists of diagnostic and prognostic analyses. The section on factors influencing reliability discusses aspects of organisational structures, programme planning and control, and critical activities. (DG)

  16. Availability allocation to repairable systems with genetic algorithms: a multi-objective formulation

    International Nuclear Information System (INIS)

    This paper describes a methodology based on genetic algorithms (GA) and experiments plan to optimize the availability and the cost of reparable parallel-series systems. It is a NP-hard problem of multi-objective combinatorial optimization, modeled with continuous and discrete variables. By using the weighting technique, the problem is transformed into a single-objective optimization problem whose constraints are then relaxed by the exterior penalty technique. We then propose a search of solution through GA, whose parameters are adjusted using experiments plan technique. A numerical example is used to assess the method

  17. Best Available Technique (BAT) assessment applied to ACR-1000 waste and heavy water management systems

    International Nuclear Information System (INIS)

    The ACR-1000 design is the next evolution of the proven CANDU reactor design. One of the key objectives for this project was to systematically apply the As Low As Reasonably Achievable (ALARA) principle to the reactor design. The ACR design team selected the Best Available Technique (BAT) assessment for this purpose to document decisions made during the design of each ACR-1000 waste and heavy water management systems. This paper describes the steps in the BAT assessment that has been applied to the ACR-1000 design. (author)

  18. A Rich Globular Cluster System in Dragonfly 17: Are Ultra-diffuse Galaxies Pure Stellar Halos?

    Science.gov (United States)

    Peng, Eric W.; Lim, Sungsoon

    2016-05-01

    Observations of nearby galaxy clusters at low surface brightness have identified galaxies with low luminosities, but sizes as large as L ⋆ galaxies, leading them to be dubbed “ultra-diffuse galaxies” (UDGs). The survival of UDGs in dense environments like the Coma cluster suggests that UDGs could reside in much more massive dark halos. We report the detection of a substantial population of globular clusters (GCs) around a Coma UDG, Dragonfly 17 (DF17). We find that DF17 has a high GC specific frequency of S N = 26 ± 13. The GC system is extended, with an effective radius of 12″ ± 2″, or 5.6 ± 0.9 kpc at Coma distance, 70% larger than the galaxy itself. We also estimate the mean of the GC luminosity function to infer a distance of {97}-14+17 Mpc, providing redshift-independent confirmation that one of these UDGs is in the Coma cluster. The presence of a rich GC system in DF17 indicates that, despite its low stellar density, star formation was intense enough to form many massive star clusters. If DF17's ratio of total GC mass to total halo mass is similar to those in other galaxies, then DF17 has an inferred total mass of ∼1011 M ⊙, only ∼10% the mass of the Milky Way, but extremely dominated by dark matter, with M/L V ≈ 1000. We suggest that UDGs like DF17 may be “pure stellar halos,” i.e., galaxies that formed their stellar halo components, but then suffered an early cessation in star formation that prevented the formation of any substantial central disk or bulge. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  19. Galactic Globular and Open Cluster Fiducial Sequences in the Pan-STARRS1 Photometric System

    CERN Document Server

    Bernard, Edouard J; Schlafly, Edward F; Platais, Imants; Bell, Eric F; Martin, Nicolas F; Rix, Hans-Walter; Slater, Colin T; Burgett, William S; Chambers, Kenneth C; Draper, Peter W; Hodapp, Klaus W; Kaiser, Nicholas; Kudritzki, Rolf-Peter; Magnier, Eugene A; Metcalfe, Nigel; Tonry, John L; Wainscoat, Richard J; Waters, Christopher

    2015-01-01

    We present the fiducial sequences of a sample of Galactic star clusters in the five bands of the Pan-STARRS1 (PS1) photometric system (g_P1, r_P1, i_P1, z_P1, y_P1). These empirical sequences -- which include the red giant and sub-giant branches, the main sequence, and the horizontal branch -- were defined from deep colour-magnitude diagrams reaching below the oldest main-sequence turn-offs of 13 globular and 3 old open clusters covering a wide range of metallicities (-2.4 < [Fe/H] < +0.4). We find excellent agreement for the nine clusters in common with previous studies in similar photometric systems when transformed to the PS1 system. Because the photometric and spectroscopic properties of these stellar populations are accurately known, the fiducials provide a solid basis for the interpretation of observations in the PS1 system, as well as valuable constraints to improve the empirical colour--$T_{eff}$ relations.

  20. Multi-objective Decision Based Available Transfer Capability in Deregulated Power System Using Heuristic Approaches

    Science.gov (United States)

    Pasam, Gopi Krishna; Manohar, T. Gowri

    2015-07-01

    Determination of available transfer capability (ATC) requires the use of experience, intuition and exact judgment in order to meet several significant aspects in the deregulated environment. Based on these points, this paper proposes two heuristic approaches to compute ATC. The first proposed heuristic algorithm integrates the five methods known as continuation repeated power flow, repeated optimal power flow, radial basis function neural network, back propagation neural network and adaptive neuro fuzzy inference system to obtain ATC. The second proposed heuristic model is used to obtain multiple ATC values. Out of these, a specific ATC value will be selected based on a number of social, economic, deregulated environmental constraints and related to specific applications like optimization, on-line monitoring, and ATC forecasting known as multi-objective decision based optimal ATC. The validity of results obtained through these proposed methods are scrupulously verified on various buses of the IEEE 24-bus reliable test system. The results presented and derived conclusions in this paper are very useful for planning, operation, maintaining of reliable power in any power system and its monitoring in an on-line environment of deregulated power system. In this way, the proposed heuristic methods would contribute the best possible approach to assess multiple objective ATC using integrated methods.

  1. Performance of a lateral pelvic cluster technical system in evaluating running kinematics.

    Science.gov (United States)

    Liew, Bernard X W; Morris, Susan; Robinson, Mark A; Netto, Kevin

    2016-06-14

    Valid measurement of pelvic and hip angles during posterior load carriage gait task requires placement of pelvic markers which will not be occluded or physically displaced by the load. One solution is the use of pure lateral pelvic clusters to track the pelvis segment. However, the validity of this method has not been compared against pelvic marker systems recommended by the International Society of Biomechanics (ISB) during high impact tasks, such as running. The purpose of this study was to validate the lateral tracking pelvic clusters against the ISB pelvis during running. Six participants performed overground running at a self-selected running speed with shoes. Three dimensional motion capture and synchronised in-ground force plates were used to determine lower limb joint angles and gait events respectively. Two biomechanical models were used to derive pelvic segment and hip joint angles. The ISB pelvis used the anterior and posterior iliac spines as anatomical and tracking markers, whilst the other model used lateral pelvic clusters as tracking markers. The between participant averaged coefficient of multiple correlation suggested good to excellent agreement between the angle waveforms generated from the two marker protocols. In addition, both marker protocols had similar sensitivity in detecting three dimensional pelvic and hip joint angles during the stance phase. This study suggests that in the event posterior load carriage is involved in running gait, pelvic and hip kinematics can be measured by the use of lateral pelvic clusters. PMID:27207384

  2. Description of alpha decay and cluster radioactivity in the dinuclear system model

    Science.gov (United States)

    Kuklin, S. N.; Adamian, G. G.; Antonenko, N. V.

    2016-03-01

    A unified description of cluster radioactivity and α-decay of cold nuclei in the dinuclear system model is proposed. Quantum dynamical fluctuations along the charge (mass) asymmetry coordinate determine the spectroscopic factor, and tunneling along the relative distance coordinate determines the penetrability of the barrier of the nucleus-nucleus interaction potential. A new method for calculating the spectroscopic factor is proposed. The hindrance factors for the orbital angular momentum transfer are studied. A potential reason for the half-life to deviate from the Geiger-Nuttall law in α-decays of neutron-deficient nuclei 194, 196Rn is found. The fine structure of α-decays of U and Th isotopes is predicted and characterized. The model is used to describe α-decays from the rotational band of even-even nuclei. The known half-lives in the regions of "lead" and "tin" radioactivities are reproduced well, and the most probable cluster yields are predicted. The cluster decay of excited nuclei is discussed. The relation of cluster radioactivity to spontaneous fission and highly deformed nuclear states is analyzed.

  3. A new Self-Adaptive disPatching System for local clusters

    Science.gov (United States)

    Kan, Bowen; Shi, Jingyan; Lei, Xiaofeng

    2015-12-01

    The scheduler is one of the most important components of a high performance cluster. This paper introduces a self-adaptive dispatching system (SAPS) based on Torque[1] and Maui[2]. It promotes cluster resource utilization and improves the overall speed of tasks. It provides some extra functions for administrators and users. First of all, in order to allow the scheduling of GPUs, a GPU scheduling module based on Torque and Maui has been developed. Second, SAPS analyses the relationship between the number of queueing jobs and the idle job slots, and then tunes the priority of users’ jobs dynamically. This means more jobs run and fewer job slots are idle. Third, integrating with the monitoring function, SAPS excludes nodes in error states as detected by the monitor, and returns them to the cluster after the nodes have recovered. In addition, SAPS provides a series of function modules including a batch monitoring management module, a comprehensive scheduling accounting module and a real-time alarm module. The aim of SAPS is to enhance the reliability and stability of Torque and Maui. Currently, SAPS has been running stably on a local cluster at IHEP (Institute of High Energy Physics, Chinese Academy of Sciences), with more than 12,000 cpu cores and 50,000 jobs running each day. Monitoring has shown that resource utilization has been improved by more than 26%, and the management work for both administrator and users has been reduced greatly.

  4. Serviceability of earthquake-damaged water systems: Effects of electrical power availability and power backup systems on system vulnerability

    International Nuclear Information System (INIS)

    Civil infrastructure systems, such as water, electrical power, natural gas, and transportation systems, are essential to the smooth functioning of modern society. Because of their inter-connected nature, once one infrastructure system is damaged by an earthquake or other natural hazard, other infrastructure systems may malfunction as well. A number of previous studies have assessed vulnerability of infrastructure systems to earthquakes, but seldom have failures due to infrastructure system interactions been considered. In its assessment of the earthquake-induced damage of a municipal water system, this paper includes the impact of damage to the supporting electrical power system using a fault tree analysis and a shortest-path algorithm. The effect of uncertainty of seismic intensity and component fragility on network integrity is evaluated. A case study involving a simple model of the electrical power system and water system in Shelby County, TN, which includes the city of Memphis, demonstrates the importance of taking infrastructure interactions into account when evaluating the seismic vulnerability and risk to a networked system, as well as the utility of back-up power systems in electric power facilities

  5. Heuristic file sorted assignment algorithm of parallel I/O on cluster computing system

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-gang; ZENG Bi-qing; XIONG Ce; DENG Xiao-heng; ZENG Zhi-wen; LIU An-feng

    2005-01-01

    A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk according to the similar service time. Firstly, the files were sorted and stored at the set I in descending order in terms of their service time, then one disk of cluster node was selected randomly when the files were to be assigned, and at last the continuous files were taken orderly from the set I to the disk until the disk reached its load maximum. The experimental results show that the new strategy improves the performance by 20.2% when the load of the system is light and by 31.6% when the load is heavy. And the higher the data access rate, the more evident the improvement of the performance obtained by the heuristic file sorted assignment algorithm.

  6. Shorter Fallow Cycles Affect the Availability of Noncrop Plant Resources in a Shifting Cultivation System

    Directory of Open Access Journals (Sweden)

    Sylvie de Blois

    2006-12-01

    Full Text Available Shifting cultivation systems, one of the most widely distributed forms of agriculture in the tropics, provide not only crops of cultural significance, but also medicinal, edible, ritual, fuel, and forage resources, which contribute to the livelihoods, health, and cultural identity of local people. In many regions across the globe, shifting cultivation systems are undergoing important changes, one of the most pervasive being a shortening of the fallow cycle. Although there has been much attention drawn to declines in crop yields in conjunction with reductions in fallow times, little if any research has focused on the dynamics of noncrop plant resources. In this paper, we use a data set of 26 fields of the same age, i.e., ~1.5 yr, but differing in the length and frequency of past fallow cycles, to examine the impact of shorter fallow periods on the availability of noncrop plant resources. The resources examined are collected in shifting cultivation fields by the Yucatec Maya in Quintana Roo, Mexico. These included firewood, which is cut from remnant trees and stumps spared at the time of felling, and 17 forage species that form part of the weed vegetation. Firewood showed an overall decrease in basal area with shorter fallow cycles, which was mostly related to the smaller diameter of the spared stumps and trees in short-fallow milpas. In contrast, forage species showed a mixed response. Species increasing in abundance in short-fallow milpas tended to be short-lived herbs and shrubs often with weedy habits, whereas those declining in abundance were predominantly pioneer trees and animal-dispersed species. Coppicing tree species showed a neutral response to fallow intensity. Within the cultural and ecological context of our study area, we expect that declines in firewood availability will be most significant for livelihoods because of the high reliance on firewood for local fuel needs and the fact that the main alternative source of firewood, forest

  7. Excited states of quantum many-body interacting systems: A variational coupled-cluster description

    OpenAIRE

    Xian, Y.

    2007-01-01

    We extend recently proposed variational coupled-cluster method to describe excitation states of quantum many-body interacting systems. We discuss, in general terms, both quasiparticle excitations and quasiparticle-density-wave excitations (collective modes). In application to quantum antiferromagnets, we reproduce the well-known spin-wave excitations, i.e. quasiparticle magnons of spin $\\pm 1$. In addition, we obtain new, spin-zero magnon-density-wave excitations which has been missing in Ans...

  8. Evolutionary Dynamics of Clustered Irregularly Interspaced Short Palindromic Repeat Systems in the Ocean Metagenome ▿

    OpenAIRE

    Sorokin, Valery A.; Gelfand, Mikhail S.; Artamonova, Irena I.

    2010-01-01

    Clustered regularly interspaced short palindromic repeats (CRISPRs) form a recently characterized type of prokaryotic antiphage defense system. The phage-host interactions involving CRISPRs have been studied in experiments with selected bacterial or archaeal species and, computationally, in completely sequenced genomes. However, these studies do not allow one to take prokaryotic population diversity and phage-host interaction dynamics into account. This gap can be filled by using metagenomic ...

  9. Plasma shape real-time control system based on Linux cluster

    International Nuclear Information System (INIS)

    In a superconducting Tokamak device, control of the plasma shape in real time is needed for equilibrating the plasma. New the development of the computer technology makes it feasible in low cost. For the HT-7U of ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences) and based on the hardcore of the offline control program--EFIT, we analyze and discuss the implement of the plasma shape real-time control system using Linux cluster technology in this paper

  10. Cluster analysis of student activity in a web-based intelligent tutoring system

    OpenAIRE

    Jugo, Igor; Kovačić, Božidar; Tijan, Edvard

    2015-01-01

    In this paper we present a model of a system for integration of an intelligent tutoring system with data mining tools. The purpose of the integration is twofold; a) to power the system adaptability based on clustering and sequential pattern mining, and b) to enable teachers (non-experts in data mining) to use data mining techniques in their web browser on a daily basis, and get useful visualizations that provide insights into the learning progress of their students. We also present an approac...

  11. 3D Viewer Platform of Cloud Clustering Management System: Google Map 3D

    Science.gov (United States)

    Choi, Sung-Ja; Lee, Gang-Soo

    The new management system of framework for cloud envrionemnt is needed by the platfrom of convergence according to computing environments of changes. A ISV and small business model is hard to adapt management system of platform which is offered from super business. This article suggest the clustering management system of cloud computing envirionments for ISV and a man of enterprise in small business model. It applies the 3D viewer adapt from map3D & earth of google. It is called 3DV_CCMS as expand the CCMS[1].

  12. INTEGRATED WORKFLOW-BASED SYSTEM FOR RISK MAPPING OF OIL SPILLS WITH USING HIGH PERFORMANCE CLUSTER

    OpenAIRE

    Kairat A. Bostanbekov; Jalal K. Jamalov; Dmitriy K. Kim; Daniyar B. Nurseitov; Ilyas E. Tursunov; Edige A. Zakarin; David L. Zaurbekov

    2013-01-01

    We present in the paper the integrated workflow-based system for risk mapping of oil spills with using high performance cluster. The design and integration methodology of the system are based on service-oriented architecture that allows provide an easy, flexible integration of any service into any desktop or mobile client. We have designed and build 4-tier SOA on the basis of W3C Web service standard. The main objective of the developing system to predict risk of a negative impact on a biota ...

  13. Research on Dynamic Distributed Computing System for Small and Medium-Sized Computer Clusters

    Institute of Scientific and Technical Information of China (English)

    Le Kang; Jianliang Xu; Feng Liu

    2012-01-01

      Distributed computing system is a science by which a complex task that need for large amount of computation can be divided into small pieces and calculated by more than one computer,and we can get the final result according to results from each computer.This paper considers a distributed computing system running in the small and medium-sized computer clusters to solve the problem that single computer has a low efficiency,and improve the efficiency of large-scale computing.The experiments show that the system can effectively improve the efficiency and it is a viable program.

  14. Soil water availability as controlling factor for actual evapotranspiration in urban soil-vegetation-systems

    Science.gov (United States)

    Thomsen, Simon; Reisdorff, Christoph; Gröngröft, Alexander; Jensen, Kai; Eschenbach, Annette

    2015-04-01

    The City of Hamburg is characterized by a large number of greens, parks and roadside trees: 600.000 trees cover about 14% of the city area, and moreover, 245.000 roadside trees can be found here. Urban vegetation is generally known to positively contribute to the urban micro-climate via cooling by evapotranspiration (ET). The water for ET is predominantly stored in the urban soils. Hence, the actual evapotranspiration (ETa) is - beside atmospheric drivers - determined by soil water availability at the soil surface and in the rooting zones of the respective vegetation. The overall aim of this study is to characterize soil water availability as a regulative factor for ETa in urban soil-vegetation systems. The specific questions addressed are: i) What is the spatio-temporal variation in soil water availability at the study sites? ii) Which soil depths are predominantly used for water uptake by the vegetation forms investigated? and iii) Which are the threshold values of soil water tension and soil water content (Θ), respectively, that limit ETa under dry conditions on both grass-dominated and tree-dominated sites? Three study areas were established in the urban region of Hamburg, Germany. We selected areas featuring both single tree stands and grass-dominated sites, both representing typical vegetation forms in Hamburg. The areas are characterized by relatively dry soil conditions. However, they differ in regard to soil water availability. At each area we selected one site dominated by Common Oak (Quercus ruber L.) with ages from 40 to 120 years, and paired each oak tree site with a neighboring grass-dominated site. All field measurements were performed during the years 2013 and 2014. At each site, we continuously measured soil water tension and Θ up to 160 cm depth, and xylem sap flux of each of three oak trees per site in a 15 min-resolution. Furthermore, we measured soil hydraulic properties as pF-curve, saturated and unsaturated conductivity at all sites

  15. A Virtual Router Cluster System Based on the Separation of the Control Plane and the Data Plane

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    This paper proposes a virtual router cluster system based on the separation of the control plane and the from multiple perspectives, such as architecture, key technologies, scenarios and standardization. To some extent, cluster simplifies network topology and management, achieves automatic conFig.uration and saves the IP address of low-cost expansion method of aggregation equipment port density

  16. A Survey of Open Clusters in the u'g'r'i'z' Filter System. 3. Results for the Cluster NGC 188

    Energy Technology Data Exchange (ETDEWEB)

    Fornal, Bartosz; Tucker, Douglas L.; Smith, J.Allyn; Allam, Sahar S.; Rider, Cristin J.; Sung, Hwankyung; /Jagiellonian U. /Fermilab /Austin Peay State U. /Wyoming U. /Johns Hopkins U. /Sejong U.

    2006-11-01

    The authors continue the series of papers describing the results of a photometric survey of open star clusters, primarily in the southern hemisphere, taken in the u'g'r'i'z' filter system. The entire observed sample covered more than 100 clusters, but here they present data only on NGC 188, which is one of the oldest open clusters known in the Milky Way. They fit the Padova theoretical isochrones to the data. Assuming a solar metallicity for NGC 188, they find a distance of 1700 {+-} 100 pc, an age of 7.5 {+-} 0.7 Gyr, and a reddening E(B-V) of 0.025 {+-} 0.005. This yields a distance modulus of 11.23 {+-} 0.14.

  17. Globular Cluster Formation in the Virgo Cluster

    CERN Document Server

    Moran, C Corbett; Lake, G

    2014-01-01

    Metal poor globular clusters (MPGCs) are a unique probe of the early universe, in particular the reionization era. Systems of globular clusters in galaxy clusters are particularly interesting as it is in the progenitors of galaxy clusters that the earliest reionizing sources first formed. Although the exact physical origin of globular clusters is still debated, it is generally admitted that globular clusters form in early, rare dark matter peaks (Moore et al. 2006; Boley et al. 2009). We provide a fully numerical analysis of the Virgo cluster globular cluster system by identifying the present day globular cluster system with exactly such early, rare dark matter peaks. A popular hypothesis is that that the observed truncation of blue metal poor globular cluster formation is due to reionization (Spitler et al. 2012; Boley et al. 2009; Brodie & Strader 2006); adopting this view, constraining the formation epoch of MPGCs provides a complementary constraint on the epoch of reionization. By analyzing both the l...

  18. Data Clustering

    Science.gov (United States)

    Wagstaff, Kiri L.

    2012-03-01

    clustering, in which some partial information about item assignments or other components of the resulting output are already known and must be accommodated by the solution. Some algorithms seek a partition of the data set into distinct clusters, while others build a hierarchy of nested clusters that can capture taxonomic relationships. Some produce a single optimal solution, while others construct a probabilistic model of cluster membership. More formally, clustering algorithms operate on a data set X composed of items represented by one or more features (dimensions). These could include physical location, such as right ascension and declination, as well as other properties such as brightness, color, temporal change, size, texture, and so on. Let D be the number of dimensions used to represent each item, xi ∈ RD. The clustering goal is to produce an organization P of the items in X that optimizes an objective function f : P -> R, which quantifies the quality of solution P. Often f is defined so as to maximize similarity within a cluster and minimize similarity between clusters. To that end, many algorithms make use of a measure d : X x X -> R of the distance between two items. A partitioning algorithm produces a set of clusters P = {c1, . . . , ck} such that the clusters are nonoverlapping (c_i intersected with c_j = empty set, i != j) subsets of the data set (Union_i c_i=X). Hierarchical algorithms produce a series of partitions P = {p1, . . . , pn }. For a complete hierarchy, the number of partitions n’= n, the number of items in the data set; the top partition is a single cluster containing all items, and the bottom partition contains n clusters, each containing a single item. For model-based clustering, each cluster c_j is represented by a model m_j , such as the cluster center or a Gaussian distribution. The wide array of available clustering algorithms may seem bewildering, and covering all of them is beyond the scope of this chapter. Choosing among them for a

  19. A study of the frictional characteristics of four commercially available self-ligating bracket systems.

    Science.gov (United States)

    Budd, Steven; Daskalogiannakis, John; Tompson, Bryan D

    2008-12-01

    The objective of this investigation was to assess and compare the in vitro tribological behaviour of four commercially available self-ligating bracket systems. The frictional characteristics of the Damon3, Speed, In-Ovation R, and Time2 bracket systems were studied using a jig that mimics the three-dimensional movements that occur during sliding mechanics. Each bracket system was tested on the following stainless steel archwires: 0.016 x 0.022, 0.019 x 0.025, 0.020 round, and 0.021 x 0.021 inch Speed D-wire. An Instron testing machine with a 50 N load cell was used to measure the frictional resistance for each bracket/tooth assembly. The crosshead speed was set at a constant rate of 1 mm/minute, and each typodont tooth was moved along a fixed wire segment for a distance of 8 mm. Descriptive statistical analysis for each bracket/archwire combination with regard to frictional resistance was performed with a two-way, balanced analysis of variance for bracket type and wire size. The Damon3 bracket consistently demonstrated the lowest frictional resistance to sliding, while the Speed bracket produced significantly (P brackets tested for any given archwire. The self-ligation design (passive versus active) appears to be the primary variable responsible for the frictional resistance generated by self-ligating brackets during translation. Passively ligated brackets produce less frictional resistance; however, this decreased friction may result in decreased control compared with actively ligated systems. PMID:18974067

  20. Implementation of a versatile research data acquisition system using a commercially available medical ultrasound scanner.

    Science.gov (United States)

    Hemmsen, Martin Christian; Nikolov, Svetoslav Ivanov; Pedersen, Mads Møller; Pihl, Michael Johannes; Enevoldsen, Marie Sand; Hansen, Jens Munk; Jensen, Jørgen Arendt

    2012-07-01

    This paper describes the design and implementation of a versatile, open-architecture research data acquisition system using a commercially available medical ultrasound scanner. The open architecture will allow researchers and clinicians to rapidly develop applications and move them relatively easy to the clinic. The system consists of a standard PC equipped with a camera link and an ultrasound scanner equipped with a research interface. The ultrasound scanner is an easy-to-use imaging device that is capable of generating high-quality images. In addition to supporting the acquisition of multiple data types, such as B-mode, M-mode, pulsed Doppler, and color flow imaging, the machine provides users with full control over imaging parameters such as transmit level, excitation waveform, beam angle, and focal depth. Beamformed RF data can be acquired from regions of interest throughout the image plane and stored to a file with a simple button press. For clinical trials and investigational purposes, when an identical image plane is desired for both an experimental and a reference data set, interleaved data can be captured. This form of data acquisition allows switching between multiple setups while maintaining identical transducer, scanner, region of interest, and recording time. Data acquisition is controlled through a graphical user interface running on the PC. This program implements an interface for third-party software to interact with the application. A software development toolkit is developed to give researchers and clinicians the ability to utilize third-party software for data analysis and flexible manipulation of control parameters. Because of the advantages of speed of acquisition and clinical benefit, research projects have successfully used the system to test and implement their customized solutions for different applications. Three examples of system use are presented in this paper: evaluation of synthetic aperture sequential beamformation, transverse

  1. Fuzzy Logic Method for Enhancement Fault-Tolerant of Cluster Head in Wireless Sensor Networks Clustering

    Directory of Open Access Journals (Sweden)

    Farnaz Pakdeland

    2016-08-01

    Full Text Available Wireless sensor network is comprised of several sensor nodes. The retaining factors influence the network operation. In the clustering structure the cluster head failure can cause loss of information.The aim of this paper is to increase tolerance error in the cluster head node. At first, paying attention to the producing balance in the density of the cluster cause to postpone the death time of the cluster head node and lessen the collision due to the lack of the energy balance in clusters. The innovation in this stage is formed by using two fuzzy logic systems. One in the phase of evaluation of the cluster head chance, and the other in the phase of producing balance and the nodes migration to the qualified clusters to increase balance, Then the focus is on recognizing and repairing the cluster head fault.

  2. Complex stellar system ESO65SC03: Open cluster or remnant?

    CERN Document Server

    Joshi, Gireesh C; Joshi, S; Chowdhury, S; Tyagi, R K

    2015-01-01

    We present a complete spatial and dynamical study of the poorly populated stellar system ESO65SC03. The radial distribution of the system gives a core and cluster radii of 1.10+/-0.63 arcmin and 5.36+/-0.24 arcmin, respectively. The surface number density profile (SNDP) does not show any clear enhancement of the surface stellar number density between the stars of the system and the field regions. We derive the optimum isochrone solution for a particular grid size in the colour-magnitude diagram (CMD) using the statistical cleaning procedure. Using the statistically cleaned CMDs, we find the distance modulus, (m-M)_0, and reddening, E({B-V}), of the system to be 11.8+/-0.2 mag and 0.45 mag, respectively. The mean proper motion of this system is -5.37+/-0.81 mas/yr and 0.31+/-0.40 in RA and DEC directions, respectively. The mean proper motion of this system is found to be almost similar to the field region. The mass function for the brighter stars is found to be too high for the system to be an open cluster. Th...

  3. Engineering, maintenance, and initiatives to improve LAMPF beam availability and system reliability

    International Nuclear Information System (INIS)

    Two different requirements are driving engineering studies and hardware development to improve LAMPF. The first is concerned with component and system improvements to increase beam availability during the LAMPF production cycle. Hardware changes in RF, power supplies, and magnets are being implemented to increase mean time between failure and reduce time to replace or repair failed units. A joint LAMPF-Industry project is on-going to improve reliability of RF components. A component test stand is being refurbished to include significant development capability. The second approach includes several changes that will increase the duty factor of the existing accelerator. Major changes are being evaluated for replacing the front end of the accelerator. Other changes improving the high brightness capability could result in a new performance plateau for LAMPF. 2 refs., 2 figs

  4. Engineering, maintenance, and new initiatives to improve LAMPF beam availability and system reliability

    International Nuclear Information System (INIS)

    Two different requirements are driving engineering studies and hardware development to improve LAMPF. The first is concerned with component and system improvements to increase beam availability during the LAMPF production cycle. Hardware changes in RF, power supplies, and magnets are being implemented to increase mean time between failure and reduce time to replace or repair failed units. A joint LAMPF-Industry project is on-going to improve reliability of RF components. A component test stand is being refurbished to include significant development capability. The second approach includes several changes that will increase the duty factor of the existing accelerator. Major changes are being evaluated for replacing the front end of the accelerator. Other changes improving high brightness capability could result in a new performance plateau for LAMPF

  5. Dietary Crude Lecithin Increases Systemic Availability of Dietary Docosahexaenoic Acid with Combined Intake in Rats.

    Science.gov (United States)

    van Wijk, Nick; Balvers, Martin; Cansev, Mehmet; Maher, Timothy J; Sijben, John W C; Broersen, Laus M

    2016-07-01

    Crude lecithin, a mixture of mainly phospholipids, potentially helps to increase the systemic availability of dietary omega-3 polyunsaturated fatty acids (n-3 PUFA), such as docosahexaenoic acid (DHA). Nevertheless, no clear data exist on the effects of prolonged combined dietary supplementation of DHA and lecithin on RBC and plasma PUFA levels. In the current experiments, levels of DHA and choline, two dietary ingredients that enhance neuronal membrane formation and function, were determined in plasma and red blood cells (RBC) from rats after dietary supplementation of DHA-containing oils with and without concomitant dietary supplementation of crude lecithin for 2-3 weeks. The aim was to provide experimental evidence for the hypothesized additive effects of dietary lecithin (not containing any DHA) on top of dietary DHA on PUFA levels in plasma and RBC. Dietary supplementation of DHA-containing oils, either as vegetable algae oil or as fish oil, increased DHA, eicosapentaenoic acid (EPA), and total n-3 PUFA, and decreased total omega-6 PUFA levels in plasma and RBC, while dietary lecithin supplementation alone did not affect these levels. However, combined dietary supplementation of DHA and lecithin increased the changes induced by DHA supplementation alone. Animals receiving a lecithin-containing diet also had a higher plasma free choline concentration as compared to controls. In conclusion, dietary DHA-containing oils and crude lecithin have synergistic effects on increasing plasma and RBC n-3 PUFA levels, including DHA and EPA. By increasing the systemic availability of dietary DHA, dietary lecithin may increase the efficacy of DHA supplementation when their intake is combined. PMID:27038174

  6. Physicians' views on resource availability and equity in four European health care systems

    Directory of Open Access Journals (Sweden)

    Slowther Anne-Marie

    2007-08-01

    Full Text Available Abstract Background In response to limited resources, health care systems have adopted diverse cost-containment strategies and give priority to differing types of interventions. The perception of physicians, who witness the effects of these strategies, may provide useful insights regarding the impact of system-wide priority setting on access to care. Methods We conducted a cross-sectional survey to ascertain generalist physicians' perspectives on resources allocation and its consequences in Norway, Switzerland, Italy and the UK. Results Survey respondents (N = 656, response rate 43% ranged in age from 28–82, and averaged 25 years in practice. Most respondents (87.7% perceived some resources as scarce, with the most restrictive being: access to nursing home, mental health services, referral to a specialist, and rehabilitation for stroke. Respondents attributed adverse outcomes to scarcity, and some respondents had encountered severe adverse events such as death or permanent disability. Despite universal coverage, 45.6% of respondents reported instances of underinsurance. Most respondents (78.7% also reported some patient groups as more likely than others to be denied beneficial care on the basis of cost. Almost all respondents (97.3% found at least one cost-containment policy acceptable. The types of policies preferred suggest that respondents are willing to participate in cost-containment, and do not want to be guided by administrative rules (11.2% or restrictions on hospital beds (10.7%. Conclusion Physician reports can provide an indication of how organizational factors may affect availability and equity of health care services. Physicians are willing to participate in cost-containment decisions, rather than be guided by administrative rules. Tools should be developed to enable physicians, who are in a unique position to observe unequal access or discrimination in their health care environment, to address these issues in a more targeted way.

  7. Assessment of Available Particle Size Data to Support an Analysis of the Waste Feed Delivery System Transfer System

    International Nuclear Information System (INIS)

    Available data pertaining to size distribution of the particulates in Hanford underground tank waste have been reviewed. Although considerable differences exist between measurement methods, it may be stated with 95% confidence that the median particle size does not exceed 275 (micro)m in at least 95% of the ten tanks selected as sources of HLW feed for Phase 1 vitrification in the RPP. This particle size is recommended as a design basis for the WFD transfer system

  8. Assessment of Available Particle Size Data to Support an Analysis of the Waste Feed Delivery System Transfer System

    Energy Technology Data Exchange (ETDEWEB)

    JEWETT, J.R.

    2000-08-10

    Available data pertaining to size distribution of the particulates in Hanford underground tank waste have been reviewed. Although considerable differences exist between measurement methods, it may be stated with 95% confidence that the median particle size does not exceed 275 {micro}m in at least 95% of the ten tanks selected as sources of HLW feed for Phase 1 vitrification in the RPP. This particle size is recommended as a design basis for the WFD transfer system.

  9. A Versatile Phenotyping System and Analytics Platform Reveals Diverse Temporal Responses to Water Availability in Setaria.

    Science.gov (United States)

    Fahlgren, Noah; Feldman, Maximilian; Gehan, Malia A; Wilson, Melinda S; Shyu, Christine; Bryant, Douglas W; Hill, Steven T; McEntee, Colton J; Warnasooriya, Sankalpi N; Kumar, Indrajit; Ficor, Tracy; Turnipseed, Stephanie; Gilbert, Kerrigan B; Brutnell, Thomas P; Carrington, James C; Mockler, Todd C; Baxter, Ivan

    2015-10-01

    Phenotyping has become the rate-limiting step in using large-scale genomic data to understand and improve agricultural crops. Here, the Bellwether Phenotyping Platform for controlled-environment plant growth and automated multimodal phenotyping is described. The system has capacity for 1140 plants, which pass daily through stations to record fluorescence, near-infrared, and visible images. Plant Computer Vision (PlantCV) was developed as open-source, hardware platform-independent software for quantitative image analysis. In a 4-week experiment, wild Setaria viridis and domesticated Setaria italica had fundamentally different temporal responses to water availability. While both lines produced similar levels of biomass under limited water conditions, Setaria viridis maintained the same water-use efficiency under water replete conditions, while Setaria italica shifted to less efficient growth. Overall, the Bellwether Phenotyping Platform and PlantCV software detected significant effects of genotype and environment on height, biomass, water-use efficiency, color, plant architecture, and tissue water status traits. All ∼ 79,000 images acquired during the course of the experiment are publicly available. PMID:26099924

  10. Visualization of Available Power Transfer Capability in a Transmission System Using Morphological Techniques

    Directory of Open Access Journals (Sweden)

    S. U. Prabha

    2009-01-01

    Full Text Available A morphological decimation technique has been proposed and implemented to analyze the available power transfer capability in a transmission power network. The method creates a graphical image of the power network with thickness of the lines proportional to their respective rated megavolt ampere (MVA capacity. Based on ac load flow solution, another image was created to represent the power flow in Megawatt (MW between the buses. Proper scaling procedure has been discussed for the construction of graphical images. The novelty of this research lies in the application of mathematical morphological techniques for decimating the created images. The image created for the MW capacities of the power lines were decimated into categories and grouped into different colors for better visualization. The multi-color image is superimposed on the input image which is created for the MVA capacity of the network. The proposed method has been tested on an IEEE test system. The results from the present approach can help the planner and operator in a power station, to get a better visualization of the power network. This is the first time this kind of multi-color visualization is presented and it can be used to find the optimal path for power transfer from one bus to another.

  11. Modeling the Metallicity Distribution of Globular Clusters

    CERN Document Server

    Muratov, Alexander L

    2010-01-01

    Observed metallicities of globular clusters reflect physical conditions in the interstellar medium of their high-redshift host galaxies. Globular cluster systems in most large galaxies display bimodal color and metallicity distributions, which are often interpreted as indicating two distinct modes of cluster formation. The metal-rich and metal-poor clusters have systematically different locations and kinematics in their host galaxies. However, the red and blue clusters have similar internal properties, such as the masses, sizes, and ages. It is therefore interesting to explore whether both metal-rich and metal-poor clusters could form by a common mechanism and still be consistent with the bimodal distribution. We present such a model, which prescribes the formation of globular clusters semi-analytically using galaxy assembly history from cosmological simulations coupled with observed scaling relations for the amount and metallicity of cold gas available for star formation. We assume that massive star clusters...

  12. Observational Evidence for a Dark Side to NGC5128's Globular Cluster System

    CERN Document Server

    Taylor, Matthew; Gomez, Matias; Woodley, Kristin

    2015-01-01

    We present a study of the dynamical properties of 125 compact stellar systems (CSSs) in the nearby giant elliptical galaxy NGC5128, using high-resolution spectra (R 26,000) obtained with VLT/FLAMES. Our results provide evidence for a new type of star cluster, based on the CSS dynamical mass scaling relations. All radial velocity (v_r) and line-of-sight velocity dispersion (sigma_los) measurements are performed with the penalized pixel fitting (ppxf) technique, which provided sigma_ppxf estimates for 115 targets. The sigma_ppxf estimates are corrected to the 2D projected half-light radii, sigma_{1/2}, as well as the cluster cores, sigma_0, accounting for observational/aperture effects and are combined with structural parameters, from high spatial resolution imaging, in order to derive total dynamical masses (M_dyn) for 112 members of NGC5128's star cluster system. In total, 89 CSSs have dynamical masses measured for the first time along with the corresponding dynamical mass-to-light ratios (Upsilon_V^dyn). We ...

  13. GRAPE-6A: A single-card GRAPE-6 for parallel PC-GRAPE cluster system

    CERN Document Server

    Fukushige, T; Kawai, A; Fukushige, Toshiyuki; Makino, Junichiro; Kawai, Atsushi

    2005-01-01

    In this paper, we describe the design and performance of GRAPE-6A, a special-purpose computer for gravitational many-body simulations. It was designed to be used with a PC cluster, in which each node has one GRAPE-6A. Such configuration is particularly effective in running parallel tree algorithm. Though the use of parallel tree algorithm was possible with the original GRAPE-6 hardware, it was not very cost-effective since a single GRAPE-6 board was still too fast and too expensive. Therefore, we designed GRAPE-6A as a single PCI card to minimize the reproduction cost and optimize the computing speed. The peak performance is 130 Gflops for one GRAPE-6A board and 3.1 Tflops for our 24 node cluster. We describe the implementation of the tree, TreePM and individual timestep algorithms on both a single GRAPE-6A system and GRAPE-6A cluster. Using the tree algorithm on our 16-node GRAPE-6A system, we can complete a collisionless simulation with 100 million particles (8000 steps) within 10 days.

  14. Cluster-controlled dimerisation in supramolecular ruthenium photosensitizer-polyoxometalate systems.

    Science.gov (United States)

    Heussner, Kirsten; Peuntinger, Katrin; Rockstroh, Nils; Rau, Sven; Streb, Carsten

    2015-01-01

    A supramolecular reaction system is reported where a labile molecular metal oxide cluster enables the unprecedented dimerisation of ruthenium photosensitizers [Ru(L)2(tmbiH2)](2+) (L = 4,4'-di-tert-butyl-2,2'-bipyridine (1a) or 2,2'-bipyridine (1b); tmbiH2 = 5,5',6,6'-tetramethyl-2,2'-bibenzimidazole). In the presence of [Mo8O26](4-) clusters (2) the dimerisation is triggered by the in situ conversion of [Mo8O26](4-) to [Mo6O19](2-) which results in the release of hydroxide ions. Simultaneous deprotonation of the pH-sensitive tmbiH2-ligands starts the dimerisation, resulting in the formation of the dinuclear complex [(Ru(L)2)2(tmbi)](2+) (L = 4,4'-di-tert-butyl-2,2'-bipyridine (3) or 2,2'-bipyridine (4)). The dimerisation reaction can be suppressed when 2 is replaced by a stable polyoxomolybdate cluster, [Mo5O15(PhPO3)2](4-) (5) and the reaction between 1a and 5 leads to the formation of hydrogen-bonded supramolecular aggregates 6. The solution and solid-state interactions in these systems were investigated using a range of spectroscopic and crystallographic techniques and compounds 3, 4 and 6 were characterized using single-crystal XRD. PMID:25381808

  15. Monte Carlo simulations of star clusters - II. Tidally limited, multi-mass systems with stellar evolution

    CERN Document Server

    Giersz, M

    2000-01-01

    A revision of Stod\\{'o}{\\l}kiewicz's Monte Carlo code is used to simulate evolution of large star clusters. A survey of the evolution of N-body systems influenced by the tidal field of a parent galaxy and by stellar evolution is presented. The results presented are in good agreement with theoretical expectations and the results of other methods (Fokker-Planck, Monte Carlo and N-body). The initial rapid mass loss, due to stellar evolution of the most massive stars, causes expansion of the whole cluster and eventually leads to the disruption of less bound systems ($W_0=3$). Models with larger $W_0$ survive this phase of evolution and then undergo core collapse and subsequent post-collapse expansion, like isolated models. The expansion phase is eventually reversed when tidal limitation becomes important. The results presented are the first major step in the direction of simulating evolution of real globular clusters by means of the Monte Carlo method.

  16. Integrated Systems for NGS Data Management and Analysis: Open Issues and Available Solutions.

    Science.gov (United States)

    Bianchi, Valerio; Ceol, Arnaud; Ogier, Alessandro G E; de Pretis, Stefano; Galeota, Eugenia; Kishore, Kamal; Bora, Pranami; Croci, Ottavio; Campaner, Stefano; Amati, Bruno; Morelli, Marco J; Pelizzola, Mattia

    2016-01-01

    Next-generation sequencing (NGS) technologies have deeply changed our understanding of cellular processes by delivering an astonishing amount of data at affordable prices; nowadays, many biology laboratories have already accumulated a large number of sequenced samples. However, managing and analyzing these data poses new challenges, which may easily be underestimated by research groups devoid of IT and quantitative skills. In this perspective, we identify five issues that should be carefully addressed by research groups approaching NGS technologies. In particular, the five key issues to be considered concern: (1) adopting a laboratory management system (LIMS) and safeguard the resulting raw data structure in downstream analyses; (2) monitoring the flow of the data and standardizing input and output directories and file names, even when multiple analysis protocols are used on the same data; (3) ensuring complete traceability of the analysis performed; (4) enabling non-experienced users to run analyses through a graphical user interface (GUI) acting as a front-end for the pipelines; (5) relying on standard metadata to annotate the datasets, and when possible using controlled vocabularies, ideally derived from biomedical ontologies. Finally, we discuss the currently available tools in the light of these issues, and we introduce HTS-flow, a new workflow management system conceived to address the concerns we raised. HTS-flow is able to retrieve information from a LIMS database, manages data analyses through a simple GUI, outputs data in standard locations and allows the complete traceability of datasets, accompanying metadata and analysis scripts. PMID:27200084

  17. Integrated Systems for NGS Data Management and Analysis: Open Issues and Available Solutions

    Science.gov (United States)

    Bianchi, Valerio; Ceol, Arnaud; Ogier, Alessandro G. E.; de Pretis, Stefano; Galeota, Eugenia; Kishore, Kamal; Bora, Pranami; Croci, Ottavio; Campaner, Stefano; Amati, Bruno; Morelli, Marco J.; Pelizzola, Mattia

    2016-01-01

    Next-generation sequencing (NGS) technologies have deeply changed our understanding of cellular processes by delivering an astonishing amount of data at affordable prices; nowadays, many biology laboratories have already accumulated a large number of sequenced samples. However, managing and analyzing these data poses new challenges, which may easily be underestimated by research groups devoid of IT and quantitative skills. In this perspective, we identify five issues that should be carefully addressed by research groups approaching NGS technologies. In particular, the five key issues to be considered concern: (1) adopting a laboratory management system (LIMS) and safeguard the resulting raw data structure in downstream analyses; (2) monitoring the flow of the data and standardizing input and output directories and file names, even when multiple analysis protocols are used on the same data; (3) ensuring complete traceability of the analysis performed; (4) enabling non-experienced users to run analyses through a graphical user interface (GUI) acting as a front-end for the pipelines; (5) relying on standard metadata to annotate the datasets, and when possible using controlled vocabularies, ideally derived from biomedical ontologies. Finally, we discuss the currently available tools in the light of these issues, and we introduce HTS-flow, a new workflow management system conceived to address the concerns we raised. HTS-flow is able to retrieve information from a LIMS database, manages data analyses through a simple GUI, outputs data in standard locations and allows the complete traceability of datasets, accompanying metadata and analysis scripts. PMID:27200084

  18. Hyperfine Fields in Complex Metallic Systems: Co Clusters Embedded in Cu

    Energy Technology Data Exchange (ETDEWEB)

    Frota-Pessoa, S., E-mail: sfpessoa@macbeth.if.usp.br; Legoas, S. B. [Universidade de Sao Paulo, Instituto de Fisica (Brazil)

    2001-03-15

    We have used first-principles linear muffin tin orbital (LMTO-ASA) electronic structure calculations, implemented directly in real space (RS) to theoretically investigate the behavior of the hyperfine field of Co clusters embedded in fcc Cu. We find that the magnitude of the dominant contact contribution to the hyperfine field decreases significantly as one goes from the Co site at the center of the cluster to those at the Co-Cu interface. To better understand this behavior, we use a simple model which closely reproduces the first-principles calculations, but is physically more transparent. Our approach can partially deconvolute the several dependences, calling attention to the processes which regulate the hyperfine field behavior in these complex Co-Cu systems.

  19. Lithium-7 surface abundance in pre-MS stars. Testing theory against clusters and binary systems

    CERN Document Server

    Tognelli, E; Moroni, P G Prada

    2012-01-01

    The disagreement between theoretical predictions and observations for surface lithium abundance in stars is a long-standing problem which indicates that the adopted physical treatment is still lacking in some points. However, thanks to the recent improvements both in models and observations, it is interesting to analyse the situation to evaluate present uncertainties. We thus present a consistent and quantitative analysis of the theoretical uncertainties affecting the current generation of models. Theoretical predictions have been tested against observational data for five open clusters, namely Ic 2602, \\alpha Per, Blanco1, Pleiades, and Ngc 2516, and four detached double-lined eclipsing binary systems. We restrict our analysis to young clusters, to avoid additional uncertainty sources such as diffusion and/or radiative levitation efficiency. By means of an up-to-date and well tested evolutionary code, i.e. FRANEC, theoretical uncertainties on surface lithium abundance predictions, during the pre-main sequenc...

  20. PARALLEL ANALYSIS OF COMBINED FINITE/DISCRETE ELEMENT SYSTEMS ON PC CLUSTER

    Institute of Scientific and Technical Information of China (English)

    WANG Fujun; Y.T.FENG; D.R.J.OWEN; ZHANG Jing; LIU Yang

    2004-01-01

    A computational strategy is presented for the nonlinear dynamic analysis of largescale combined finite/discrete element systems on a PC cluster. In this strategy, a dual-level domain decomposition scheme is adopted to implement the dynamic domain decomposition. The domain decomposition approach perfectly matches the requirement of reducing the memory size per processor of the calculation. To treat the contact between boundary elements in neighbouring subdomains, the elements in a subdomain are classified into internal, interfacial and external elements. In this way, all the contact detect algorithms developed for a sequential computation could be adopted directly in the parallel computation. Numerical examples show that this implementation is suitable for simulating large-scale problems. Two typical numerical examples are given to demonstrate the parallel efficiency and scalability on a PC cluster.

  1. Largest Lyapunov exponent in molecular systems. II: Quaternion coordinates and application to methane clusters.

    Science.gov (United States)

    Calvo, F

    1999-09-01

    We present a numerical procedure for extracting Lyapunov characteristic exponents from classical molecular-dynamics simulations of molecular systems. The theoretical frame chosen to describe the orientational degrees of freedom is the quaternions scheme. We apply the method to small methane clusters. Two different model potentials are used to investigate the role of internal molecular motion on the nonlinear dynamics, and several parameters are calculated to study the thermodynamics and chaotic dynamics of these clusters. Evidence is found for a solidlike to plasticlike phase transition occurring with the release of the orientational degrees of freedom, at low temperatures below the melting point. The largest Lyapunov exponent increases significantly during this transition, but it exhibits no particular variation during melting. PMID:11970082

  2. Cluster emission at pre-equilibrium stage in Heavy Nuclear Reactions. A Model considering the Thermodynamics of Small Systems

    International Nuclear Information System (INIS)

    Cluster emission at pre-equilibrium stage, in heavy ion fusion reactions of 12C and 16O nuclei with 116Sn, 208Pb, 238U are studied. the energy of the projectile nuclei was chosen at 0.25GeV, 0.5GeV and 1GeV. A cluster formation model is developed in order to calculate the cluster size. Thermodynamics of small systems was used in order to examine the cluster behavior inside the nuclear media. This model is based on considering two phases inside the compound nucleus, on one hand the nuclear media phase, and on the other hand the cluster itself. The cluster acts like an instability inside the compound nucleus, provoking an exchange of nucleons with the nuclear media through its surface. The processes were simulated using Monte Carlo methods. We obtained that the cluster emission probability shows great dependence on the cluster size. This project is aimed to implement cluster emission processes, during the pre-equilibrium stage, in the frame of CRISP code (Collaboration Rio-Sao Paulo). (Author)

  3. Load-Balance Policy in Two Level-Cluster File System

    Institute of Scientific and Technical Information of China (English)

    LIU Yuling; SONG Weiwei; MA Xiaoxue

    2006-01-01

    In this paper, we explored a load-balancing algorithm in a cluster file system contains two levels of metadata-server,primary-level server quickly distributestasks to second-level servers depending on the closest load-balancing information. At the same time, we explored a method which accurately reflect I/O traffic and storage of storage-node: computing the heat-value of file, according to which we realized a more logical storage allocation. According to the experiment result, we conclude that this new algorithm shortens the executing time of tasks and improves the system performance compared with other load algorithm.

  4. Strong Clustering of High-Redshift Lyman-alpha Forest Absorption Systems

    OpenAIRE

    Fernandez-Soto, A.; Lanzetta, K. M.; Barcons, X.; Carswell, R. F.; Webb, J. K.; Yahil, A.

    1996-01-01

    We use new observations of very weak CIV absorption lines associated with high-redshift Lyman-alpha absorption systems to measure the high-redshift Lyman-alpha line two-point correlation function (TPCF). These very weak CIV absorption lines trace small-scale velocity structure that cannot be resolved by Lyman-alpha absorption lines. We find that (1) high-redshift Lyman-alpha absorption systems with N(HI) > 3.10^14 cm^{-2} are strongly clustered in redshift, (2) previous measurements of the Ly...

  5. Intelligent Pattern Mining and Data Clustering for Pattern Cluster Analysis using Cancer Data

    Directory of Open Access Journals (Sweden)

    G.Raj Kumar

    2010-12-01

    Full Text Available Data mining techniques are used for the knowledge discovery process under the large data set environment. Clustering techniques are used to group up the relevant data sets. Hierarchical and partitioned clustering techniques are used for the clustering process. The clustering process is the complex task with high process time. The pattern extraction scheme is applied to find frequent item sets. Association rule mining techniques are applied to carry out the pattern extraction process. The pattern extraction scheme and the clustering scheme are integrated in the simultaneous pattern extraction and clustering scheme. The clustering process is improved with pattern comparison and transaction transfer process. The simultaneous clustering scheme is implemented to analyze the cancer patient diagnosis reports. The system is implemented as four major modules data set management, pattern extraction, clustering process and performance analysis. The data sets are preprocessed before the pattern extraction process. The patterns are used in the simultaneous clustering process. The performance analysis is done with the comparison of the data clustering scheme and pattern clustering schemes. The process time and memory factors are used in the performance analysis process. The cluster accuracy is represented using the fitness values. The system is enhanced with the K-means clustering algorithm.

  6. A COMPARATIVE STUDY OF FUZZY MODELS IN DOCUMENT CLUSTERING

    Directory of Open Access Journals (Sweden)

    G.MANIMEKALAI

    2012-01-01

    Full Text Available The availability of large quantity of text documents from the World Wide Web and business document management systems has made the dynamic separation of texts into new categories as a very important task for every business intelligence systems. Text document clustering is one of the emerging and most needed clustering techniques used to cluster documents with regard to similarity amongdocuments. It is used widely in digital library management system in the modern context. Document clustering is widely applicable in areas such as search engines, web mining, information retrieval, andtopological analysis. There are several clustering approaches available in the literature to cluster the document. But most of the existing clustering techniques suffer from a wide range of limitations. The existing clustering approaches face the issues like practical applicability, very less accuracy, more classification time etc. Thus a novel approach is needed for providing significant accuracy with less classification time. In recent times, inclusion of fuzzy logic in clustering provides better clustering results. One of the widely used fuzzy logic based clustering is Fuzzy C-Means (FCM Clustering. In order to further improve the performance of clustering, this thesis uses Modified Fuzzy C-Means (MFCMClustering. The documents are ranked using Term Frequency–Inverse Document Frequency (TF–IDF technique. From the experimental results, it can be observed that the proposed technique results in betterclustering when compared to the FCM clustering technique.

  7. Falcon: neural fuzzy control and decision systems using FKP and PFKP clustering algorithms.

    Science.gov (United States)

    Tung, W L; Quek, C

    2004-02-01

    Neural fuzzy networks proposed in the literature can be broadly classified into two groups. The first group is essentially fuzzy systems with self-tuning capabilities and requires an initial rule base to be specified prior to training. The second group of neural fuzzy networks, on the other hand, is able to automatically formulate the fuzzy rules from the numerical training data. Examples are the Falcon-ART, and the POPFNN family of networks. A cluster analysis is first performed on the training data and the fuzzy rules are subsequently derived through the proper connections of these computed clusters. This correspondence proposes two new networks: Falcon-FKP and Falcon-PFKP. They are extensions of the Falcon-ART network, and aimed to overcome the shortcomings faced by the Falcon-ART network itself, i.e., poor classification ability when the classes of input data are very similar to each other, termination of training cycle depends heavily on a preset error parameter, the fuzzy rule base of the Falcon-ART network may not be consistent Nauck, there is no control over the number of fuzzy rules generated, and learning efficiency may deteriorate by using complementarily coded training data. These deficiencies are essentially inherent to the fuzzy ART, clustering technique employed by the Falcon-ART network. Hence, two clustering techniques--Fuzzy Kohonen Partitioning (FKP) and its pseudo variant PFKP, are synthesized with the basic Falcon structure to compute the fuzzy sets and to automatically derive the fuzzy rules from the training data. The resultant neural fuzzy networks are Falcon-FKP and Falcon-PFKP, respectively. These two proposed networks have a lean and efficient training algorithm and consistent fuzzy rule bases. Extensive simulations are conducted using the two networks and their performances are encouraging when benchmarked against other neural and neural fuzzy systems. PMID:15369109

  8. Selective Cluster-Based Temperature Monitoring System for Homogeneous Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Sudhanshu Tyagi; Sudeep Tanwar; Sumit Kumar Gupta; Neeraj Kumar; Joel JPC Rodrigues

    2014-01-01

    Over the past few decades, there has been a revolution in ICT, and this has led to the evolution of wireless sensor networks (WSN), in particular, wireless body area networks. Such networks comprise a specialized collection of sensor nodes (SNs) that may be deployed randomly in a body area network to collect data from the human body. In a health monitoring system, it may be es-sential to maintain constant environmental conditions within a specific area in the hospital. In this paper, we propose a tempera-ture-monitoring system and describe a case study of a health-monitoring system for patents critically ill with the same disease and in the same environment. We propose Enhanced LEACH Selective Cluster (E-LEACH-SC) routing protocol for monitoring the tem-perature of an area in a hospital. We modified existing Selective Cluster LEACH protocol by using a fixed-distance-based thresh-old to divide the coverage region in two subregions. Direct data transmission and selective cluster-based data transmission ap-proaches were used to provide short-range and long-distance coverage for the collection of data from the body of ill patients. Ex-tensive simulations were run by varying the ratio of node densities of the two subregions in the health-monitoring system. Last Node Alive (LNA), which is a measure of network lifespan, was the parameter for evaluating the performance of the proposed scheme. The simulation results show that the proposed scheme significantly increases network lifespan compared with traditional LEACH and LEACH-SC protocols, which by themselves improve the overall performance of the health-monitoring system.

  9. Integrated interpretation of AE clusters and fracture system in Hijiori HDR artificial reservoir; Hijiori koon gantai jinko choryuso no AE cluster to kiretsu system ni kansuru togoteki kaishaku

    Energy Technology Data Exchange (ETDEWEB)

    Tezuka, K. [Japan Petroleum Exploration Corp., Tokyo (Japan); Niitsuma, H. [Tohoku University, Sendai (Japan)

    1997-05-27

    With regard to a fracture system in the Hijiori hot dry rock artificial reservoir, an attempt was made on an interpretation which integrates different data. Major factors that characterize development and performance of an artificial reservoir are composed of a fracture system in rocks, which acts as circulating water paths, a heat exchange face and a reservoir space. The system relates not only with crack density distribution, but also with cracks activated by water pressure fracturing, cracks generating acoustic emission (AE), and cracks working as major flow paths, all of which are characterized by having respective behaviors and roles. Characteristics are shown on AE cluster distribution, crack distribution, production zone and estimated stress fields. Mutual relationship among these elements was discussed based on the Coulomb`s theory. The most important paths are characterized by distribution of slippery cracks. Directions and appearance frequencies of the slippery cracks affect strongly directionality of the paths, which are governed by distribution of the cracks (weak face) and stress field. Among the slippery cracks, cracks that generate AE are cracks that release large energy when a slip occurs. Evaluation on slippery crack distribution is important. 7 refs., 8 figs.

  10. Pharmacokinetics and pharmacodynamics of propranolol in hypertensive patients after sublingual administration: systemic availability

    Directory of Open Access Journals (Sweden)

    A.P. Mansur

    1998-05-01

    Full Text Available The bioavailability of propranolol depends on the degree of liver metabolism. Orally but not intravenously administered propranolol is heavily metabolized. In the present study we assessed the pharmacokinetics and pharmacodynamics of sublingual propranolol. Fourteen severely hypertensive patients (diastolic blood pressure (DBP ³115 mmHg, aged 40 to 66 years, were randomly chosen to receive a single dose of 40 mg propranolol hydrochloride by sublingual or peroral administration. Systolic (SBP and diastolic (DBP blood pressures, heart rate (HR for pharmacodynamics and blood samples for noncompartmental pharmacokinetics were obtained at baseline and at 10, 20, 30, 60 and 120 min after the single dose. Significant reductions in BP and HR were obtained, but differences in these parameters were not observed when sublingual and peroral administrations were compared as follows: SBP (17 vs 18%, P = NS, DBP (14 vs 8%, P = NS and HR (22 vs 28%, P = NS, respectively. The pharmacokinetic parameters obtained after sublingual or peroral drug administration were: peak plasma concentration (CMAX: 147 ± 72 vs 41 ± 12 ng/ml, P<0.05; time to reach CMAX (TMAX: 34 ± 18 vs 52 ± 11 min, P<0.05; biological half-life (t1/2b: 0.91 ± 0.54 vs 2.41 ± 1.16 h, P<0.05; area under the curve (AUCT: 245 ± 134 vs 79 ± 54 ng h-1 ml-1, P<0.05; total body clearance (CLT/F: 44 ± 23 vs 26 ± 12 ml min-1 kg-1, P = NS. Systemic availability measured by the AUCT ratio indicates that extension of bioavailability was increased 3 times by the sublingual route. Mouth paresthesia was the main adverse effect observed after sublingual administration. Sublingual propranolol administration showed a better pharmacokinetic profile and this route of administration may be an alternative for intravenous or oral administration.

  11. Geographical Clustering of Juvenile Onset Systemic Lupus Erythematosus within the Sultanate of Oman

    Directory of Open Access Journals (Sweden)

    Ibrahim Al-Zakwani

    2013-05-01

    Full Text Available Objective: While SLE is found worldwide, there is diversity in clinical presentation of the disease according to geographical variations. The aim of this study is to describe geographical distributions of childhood onset SLE within Oman to identify geographical clustering and to compare the demographic, clinical, and immunological characteristics of this cluster against the rest of Oman.Methods: We retrospectively reviewed the hospital charts of 104 consecutive children with childhood onset SLE who were seen in pediatric rheumatology centers in the Sultanate of Oman over a 15-year period between 1995 and 2010.Results: Geographical clustering of childhood onset SLE was identified in Sharqiya region, which constituted 41% (n=43 of all cases in Oman. This cohort of patients had characteristic disease features which consisted of significantly more boys affected with SLE compared to the rest of the country (42% versus 15%; p=0.002. These children also tended to be younger (10.3 versus 16.5 years; p=0.001, diagnosed at an earlier age (6.4 versus 9.4 years; p<0.001 with a stronger family history of SLE (58% versus 33%; p=0.010. These children also had increased incidence of mucocutanous changes (81% versus 62%; p=0.036 and decreased hematological abnormalities (30% versus 51%; p=0.036.Conclusion: We identified geographical clustering of childhood onset SLE to Sharqiya region in Oman which is associated with unique demographical and clinical features. Whether increased prevalence of disease in this region is due to geographical, environmental, ethnic or genetic factors is yet to be determined. However, it is likely to be interplay of known and other unrecognized factors.

  12. The dynamical evolution of multi-planet systems in open clusters

    CERN Document Server

    Hao, W; Spurzem, R

    2013-01-01

    The majority of stars form in star clusters and many are thought to have planetary companions. We demonstrate that multi-planet systems are prone to instabilities as a result of frequent stellar encounters in these star clusters much more than single-planet systems. The cumulative effect of close and distant encounters on these planetary systems are investigated using Monte Carlo scattering experiments. We consider two types of planetary configurations orbiting Sun-like stars: (i) five Jupiter-mass planets in the semi-major axis range 1-42 AU orbiting a Solar mass star, with orbits that are initially co-planar, circular, and separated by 10 mutual Hill radii, and (ii) the four gas giants of our Solar system. Planets with short orbital periods are not directly affected by encountering stars. However, secular evolution of perturbed systems may result in the ejection of the innermost planets or in physical collisions of the innermost planets with the host star, up to many thousands of years after a stellar encou...

  13. Fractal-cluster theory and thermodynamic principles of the control and analysis for the self-organizing systems

    CERN Document Server

    Volov, V T

    2013-01-01

    The theory of resource distribution in self-organizing systems on the basis of the fractal-cluster method has been presented. This theory consists of two parts: determined and probable. The first part includes the static and dynamic criteria, the fractal-cluster dynamic equations which are based on the fractal-cluster correlations and Fibonacci's range characteristics. The second part of the one includes the foundations of the probable characteristics of the fractal-cluster system. This part includes the dynamic equations of the probable evolution of these systems. By using the numerical researches of these equations for the stationary case the random state field of the one in the phase space of the $D$, $H$, $F$ criteria have been obtained. For the socio-economical and biological systems this theory has been tested.

  14. A Research on Competitiveness of Guangxi City - Based on System Clustering Method and Principal Component Analysis Method

    OpenAIRE

    Fan, Chang-ke; Wu, Yu

    2010-01-01

    A total of 10 indices of regional economic development in Guangxi are selected. According to the relevant economic data, regional economic development in Guangxi City is analyzed by using System Clustering Method and Principal Component Analysis Method. Result shows that System Clustering Method and Principal Component Analysis Method have revealed similar results analysis of economic development level. Overall economic strength of Guangxi is weak and Nanning has relatively high scores of fac...

  15. Near Fermi Energy reaction dynamics and clustering in alpha-conjugate systems

    Science.gov (United States)

    Cao, Xiguang; Schmidt, Katarzyna; Kim, E.-J.; Hagel, K.; Barbui, M.; Wuenschel, S.; Natowitz, J. B.; Zheng, H.; Blando, N.; Bonasera, A.; Giuliani, G.

    2015-10-01

    Theoretical study predicted that the self-organizing of alpha cluster is favored over deuteron below a critical density with moderate temperature, where the possible Bose-Einstein condensation (BEC) is expected to occur. However the experimental information about the alpha states at low density is scarce. It is natural to pursue experiments with α conjugate beams and advanced detection apparatus to explore the collective dynamics of alpha clustered systems at low density. Systematical experiments were carried out with 40Ca and 28Si beams at 10, 25, 35 MeV/u incident on 28Si, 12C, 40Ca and 180Ta targets, detected with the NIMROD-ISiS 4 Pi detector array. It is found that there is a strong neck-like emission, which consists mainly of alpha-like fragments. The characteristic of the α emission source is explored by shape analysis, multi-particle correlation and quantum fluctuation approaches. How these observables reveal the possible alpha BEC in low density and possible exotic toroidal and linear chain configurations made out of alpha clusters is discussed.

  16. Wide-Field Hubble Space Telescope Observations of the Globular Cluster System in NGC1399

    CERN Document Server

    Puzia, Thomas H; Goudfrooij, Paul; Maccarone, Thomas J; Fabbiano, Giuseppina; Angelini, Lorella

    2014-01-01

    We present a comprehensive high spatial-resolution imaging study of globular clusters (GCs) in NGC1399, the central giant elliptical cD galaxy in the Fornax galaxy cluster, conducted with HST/ACS. Using a novel technique to construct drizzled PSF libraries for HST/ACS data, we accurately determine the fidelity of GC structural parameter measurements from detailed artificial star cluster experiments. The measurement of rh for the major fraction of the NGC1399 GC system reveals a trend of increasing rh versus galactocentric distance, Rgal, out to about 10 kpc and a flat relation beyond. This trend is very similar for blue and red GCs which are found to have a mean size ratio of rh(red)/rh(blue)=0.82+/-0.11 at all galactocentric radii from the core regions of the galaxy out to ~40 kpc. This suggests that the size difference between blue and red GCs is due to internal mechanisms related to the evolution of their constituent stellar populations. Modeling the mass density profile of NGC1399 shows that additional ex...

  17. Enhanced dissolution and systemic availability of albendazole formulated as solid dispersions.

    Science.gov (United States)

    Castro, Silvina G; Sanchez Bruni, Sergio F; Urbizu, Lucía P; Confalonieri, Alejandra; Ceballos, Laura; Lanusse, Carlos E; Allemandi, Daniel A; Palma, Santiago D

    2013-01-01

    Solid dispersions (SDs) containing the anthelmintic compound albendazole (ABZ) and either Pluronic 188 (P 188) or polyethylene glycol 6000 (PEG 6000) as hydrophilic carriers were formulated. Drug-polymers interactions in solid state were investigated using different techniques. Only a 4% of total ABZ was dissolved at 5 min post-incubation, reaching dissolution rates of 32.8% (PEG 6000) and 69.4% (P 188) in SDs. In this way, P 188 was substantially more efficient as ABZ dissolution promoter in comparison to PEG 6000, especially at the initial stages of the dissolution processes (suspension. Consistently, the Cmax increased 130% (p < 0.001) following treatment with P 188 based SD ABZ formulation. For the ABZ-PEG 6000 SD formulation, the favorable effect on ABZ systemic availability did not reached statistical significance compared to the control group. The study reported here showed the utility of pharmacokinetic assays performed on mice as a model for preliminary drug formulation screening studies. PMID:22670782

  18. Investigation of the industrial clusters in Islamic Republic of Iran (Case Study of Yazd city usinglocal production systems method &Industry Perception Model

    Directory of Open Access Journals (Sweden)

    Seyed Valiollah MirHosseini

    2011-10-01

    Full Text Available All countries hope to achieve increasingly developments which grow fast. Nowadays many developed countries are using strategy of industrial clusters development because they influence the competitiveness of industrial clusters in the country as well as beyond national borders and show new ways of thinking about the place of dealing and earning. Industrial clusters influence competition through increasing of productivity based on settlement of companies and providing quick guidelines for development and innovation and encouraging of new business. Industrial cluster is one of new combined methods of various theories such as theory of economic geography, regional economics, national innovation system, transmitting knowledge theories, social capital theories and social networks .Recently this method in Iran attracted many attentions based on industries compatible with mentioned method which attempts to provide a better and competitive market place for the country, region and the world. In this study literature of industrial clusters is initially reviewed and then data analysis methods, used model and eventually results of this paper will be dealt with.

  19. Evidence for a Dark Side to NGC 5128’s Globular Cluster System

    Science.gov (United States)

    Hyazinth Puzia, Thomas; Taylor, Matthew Alan

    2015-08-01

    Evidence for a new type of star cluster from the dynamical mass scaling relations of compact stellar systems (CSSs) will be presented, based on a study of 125 CSSs around the nearby giant elliptical galaxy NGC 5128, using high-resolution spectra (R=26000) obtained with VLT/FLAMES. All radial velocity (vr) and line-of-sight velocity dispersion (σlos) measurements are performed with the penalized pixel fitting (ppxf) technique. The σlos estimates are corrected to the 2D projected half-light radii, (σ1/2), as well as the cluster cores, (σ0), accounting for observational/aperture effects and are combined with structural parameters in order to derive dynamical half-mass estimates (M1/2), and total dynamical masses (Mdyn), for 116 CSSs around NGC 5128. In total, 93 CSSs have Mdyn measured for the first time along with the corresponding dynamical mass-to-light ratios (M/L)dyn. We find two distinct sequences in the (M/L)dyn-Mdyn plane, which are well fit by power laws of the forms (M/L)dyn ~ M(0.33+/-0.04) and (M/L)dyn ~ M(0.91+/-0.04). The shallower sequence corresponds to the very bright tail of the globular cluster luminosity function (GCLF), with indications for angular momentum content that increases with Mdyn. The steeper relation appears to be populated by a distinct group of objects with significant dark gravitating mass components, such as central massive black holes and/or exotically compact dark matter distributions. This result would suggest that the formation and evolution of these CSSs is markedly different from the classical globular clusters in NGC 5128 despite the fact that they have luminosities similar to the GCLF turn-over magnitude.

  20. Availability and Reliability of Disaster Early Warning Systems and the IT Infrastructure Library

    Science.gov (United States)

    Wächter, J.; Loewe, P.

    2012-12-01

    The Boxing Day Tsunami of 2004 caused an information catastrophy. Crucial early warning information could not be delivered to the communities under imminent threat, resulting in over 240,000 casualties in 14 countries. This tragedy sparked the development of a new generation of integrated modular Tsunami Early Warning Systems (TEWS). While significant advances were accomplished in the past years, recent events, like the Chile 2010 and the Tohoku 2011 tsunami demonstrate that the key technical challenge for Tsunami Early Warning research on the supranational scale still lies in the timely issuing of status information and reliable early warning messages. A key challenge stems from the main objective of the IOC Tsunami Programme, the integration of national TEWS towards ocean-wide networks: Each of the increasing number of integrated Tsunami Early Warning Centres has to cope with the continuing evolution of sensors, hardware and software while having to maintain reliable inter-center information exchange services. To avoid future information catastrophes, the performance of all components, ranging from sensors to Warning Centers, has to be regularly validated against defined criteria. This task is complicated by the fact that in term of ICT system life cycles tsunami are very rare event resulting in very difficult framing conditions to safeguard the availability and reliability of TWS. Since 2004, GFZ German Research Centre for Geosciences (GFZ) has built up expertise in the field of TEWS. Within GFZ, the Centre for GeoInformation Technology (CEGIT) has focused its work on the geoinformatics aspects of TEWS in two projects already: The German Indonesian Tsunami Early Warning System (GITEWS) funded by the German Federal Ministry of Education and Research (BMBF) and the Distant Early Warning System (DEWS), a European project funded under the sixth Framework Programme (FP6). These developments are continued in the TRIDEC project (Collaborative, Complex, and Critical

  1. A Content-Based Parallel Image Retrieval System on Cluster Architectures

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bing; SHEN Jun-yi; PENG Qin-ke

    2004-01-01

    We propose a content-based parallel image retrieval system to achieve high responding ability.Our system is developed on cluster architectures.It has several retrieval servers to supply the service of content-based image retrieval.It adopts the Browser/Server (B/S) mode.The users could visit our system though web pages.It uses the symmetrical color-spatial features (SCSF) to represent the content of an image.The SCSF is effective and efficient for image matching because it is independent of image distortion such as rotation and flip as well as it increases the matching accuracy.The SCSF was organized by M-tree, which could speedup the searching procedure.Our experiments show that the image matching is quickly and efficiently with the use of SCSF.And with the support of several retrieval servers, the system could respond to many users at mean time.

  2. Possible Self-Organised Criticality and Dynamical Clustering of Traffic flow in Open Systems

    CERN Document Server

    Larraga, M E; Mehta, A; Mehta, Anita

    1999-01-01

    We focus in this work on the study of traffic in open systems using a modified version of an existing cellular automaton model. We demonstrate that the open system is rather different from the closed system in its 'choice' of a unique steady-state density and velocity distribution, independently of the initial conditions, reminiscent of self-organised criticality. Quantities of interest such as average densities and velocities of cars, exhibit phase transitions between free flow and the jammed state, as a function of the braking probability R in a way that is very different from closed systems. Velocity correlation functions show that the concept of a dynamical cluster, introduced earlier in the context of granular flow is also relevant for traffic flow models.

  3. Biochar increases plant available water in a sandy soil under an aerobic rice cropping system

    Directory of Open Access Journals (Sweden)

    M. T. de Melo Carvalho

    2014-03-01

    Full Text Available The main objective of this study was to assess the impact of biochar rate (0, 8, 16 and 32 t ha−1 on the water retention capacity (WRC of a sandy Dystric Plinthosol. The applied biochar was a by-product of slow pyrolysis (∼450 °C of eucalyptus wood, milled to pass through a 2000 μm sieve that resulted in a material with an intrinsic porosity ≤10 μm and a specific surface area of ∼3.2 m2 g−1. The biochar was incorporated into the top 15 cm of the soil under an aerobic rice system. Our study focused on both the effects on WRC and rice yields at 2 and 3 years after application. Undisturbed soil samples were collected from 16 plots in two soil layers (5–10 and 15–20 cm. Soil water retention curves were modelled using a nonlinear mixed model which appropriately accounts for uncertainties inherent of spatial variability and repeated measurements taken within a specific soil sample. We found an increase in plant available water in the upper soil layer proportional to the rate of biochar, with about 0.8% for each t ha−1 of biochar amendment at 2 and 3 years after application. The impact of biochar on soil WRC was most likely related to an increase in overall porosity of the sandy soil, which was evident from an increase in saturated soil moisture and macro porosity with 0.5% and 1.6% for each t ha−1 of biochar applied, respectively. The increment in soil WRC did not translate into an increase in rice yield, essentially because in both seasons the amount of rainfall during critical period for rice production exceeded 650 mm. The use of biochar as a soil amendment can be a worthy strategy to guarantee yield stability under water limited conditions. Our findings raise the importance of assessing the feasibility of very high application rates of biochar and the inclusion of a detailed analysis of its physical and chemical properties as part of future investigations.

  4. Improvement of availability and safety of nuclear power plants by advanced monitoring and diagnostic systems

    International Nuclear Information System (INIS)

    During the past decades AREVA NP GmbH has developed a new generation of M and D systems to improve the reliability and quality of monitoring techniques. The Loose Parts Monitoring System, Vibration Monitoring System, Leak Detection System and the Fatigue Monitoring System belong to the family of operational M and D systems while the System for Monitoring of Rotating Machines and the Valve Monitoring system supports the condition based maintenance. The presentation will discuss the key parameters and functions of these system and their applications in AREVA's new EPR design. System functions as well as operational experiences will be presented and discussed. Mathematical methods used to increase the sensitivity and to reduce fault alarms will be discussed in parallel with results of the new system development efforts. As a special issue to the life time extension of NPPs, the Areva Fatigue Concept will be presented, too.

  5. Improvement of availability and safety of nuclear power plants by advanced monitoring and diagnostic systems

    Energy Technology Data Exchange (ETDEWEB)

    Bechtold, B.

    2012-07-01

    During the past decades AREVA NP GmbH has developed a new generation of M and D systems to improve the reliability and quality of monitoring techniques. The Loose Parts Monitoring System, Vibration Monitoring System, Leak Detection System and the Fatigue Monitoring System belong to the family of operational M and D systems while the System for Monitoring of Rotating Machines and the Valve Monitoring system supports the condition based maintenance. The presentation will discuss the key parameters and functions of these system and their applications in AREVA's new EPR design. System functions as well as operational experiences will be presented and discussed. Mathematical methods used to increase the sensitivity and to reduce fault alarms will be discussed in parallel with results of the new system development efforts. As a special issue to the life time extension of NPPs, the Areva Fatigue Concept will be presented, too.

  6. Objective Classification of Rainfall in Northern Europe for Online Operation of Urban Water Systems Based on Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Roland Löwe

    2016-03-01

    Full Text Available This study evaluated methods for automated classification of rain events into groups of “high” and “low” spatial and temporal variability in offline and online situations. The applied classification techniques are fast and based on rainfall data only, and can thus be applied by, e.g., water system operators to change modes of control of their facilities. A k-means clustering technique was applied to group events retrospectively and was able to distinguish events with clearly different temporal and spatial correlation properties. For online applications, techniques based on k-means clustering and quadratic discriminant analysis both provided a fast and reliable identification of rain events of “high” variability, while the k-means provided the smallest number of rain events falsely identified as being of “high” variability (false hits. A simple classification method based on a threshold for the observed rainfall intensity yielded a large number of false hits and was thus outperformed by the other two methods.

  7. "Dark" systems in globular clusters: GWs emission and limits on the formation of IMBHs

    CERN Document Server

    Arca-Sedda, Manuel

    2016-01-01

    Many observed globular clusters (GCs) seem to show a central overabundance of mass whose nature has not yet fully understood. Indeed, it is not clear whether it is due to a central intermediate mass black hole (IMBH) or to a massive stellar system (MSS) composed of mass segregated stars. In this contribution we present a semi-analytic approach to the problem complemented by 12 $N$-body simulations in which we followed the formation of MSSs in GCs with masses up to $3\\times 10^5$ \\Ms. Some implications for the formation of IMBHs and gravitational waves emission are discussed in perspective of a future work.

  8. Parallel File System I/O Performance Testing On LANL Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Wiens, Isaac Christian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). High Performance Computing Division. Programming and Runtime Environments; Green, Jennifer Kathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). High Performance Computing Division. Programming and Runtime Environments

    2016-08-18

    These are slides from a presentation on parallel file system I/O performance testing on LANL clusters. I/O is a known bottleneck for HPC applications. Performance optimization of I/O is often required. This summer project entailed integrating IOR under Pavilion and automating the results analysis. The slides cover the following topics: scope of the work, tools utilized, IOR-Pavilion test workflow, build script, IOR parameters, how parameters are passed to IOR, *run_ior: functionality, Python IOR-Output Parser, Splunk data format, Splunk dashboard and features, and future work.

  9. Moessbauer spectroscopy in disordered magnetic systems: Clustering effects in AuFe reentrant ferromagnet

    International Nuclear Information System (INIS)

    Basic properties of magnetic reentrant systems are reported. The results obtained with Moessbauer Spectroscopy, are briefly reviewed and critically discussed. Particular emphasis is placed on the case of Au1-xFex (x>15%) reentrant ferromagnet. In the light of our experiments under external field, a model is proposed, describing the microscopic structure as an assembly of small weakly coupled superparamagnetic clusters. We believe that this short scale effect is not in disagreement with the existence of large ferromagnetic domains (≅50μ) recently observed by electron transmission microscopy on similar reentrant alloys by Senoussi et al. (orig.)

  10. THE ACS VIRGO CLUSTER SURVEY. XVII. THE SPATIAL ALIGNMENT OF GLOBULAR CLUSTER SYSTEMS WITH EARLY-TYPE HOST GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qiushi; Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); Blakeslee, John P.; Cote, Patrick; Ferrarese, Laura [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Jordan, Andres [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Mei, Simona [University of Paris 7 Denis Diderot, F-75205 Paris Cedex 13 (France); West, Michael J., E-mail: peng@pku.edu.cn [Maria Mitchell Observatory, 4 Vestal Street, Nantucket, MA 02554 (United States)

    2013-06-01

    We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation ({epsilon} > 0.2) and intermediate to high luminosities (M{sub z} < -19), the GCs are preferentially aligned along the major axis of the stellar light. The red (metal-rich) GC subpopulations show strong alignment with the major axis of the host galaxy, which supports the notion that these GCs are associated with metal-rich field stars. The metal-rich GCs in lenticular galaxies show signs of being more strongly associated with disks rather than bulges. Surprisingly, we also find that the blue (metal-poor) GCs can also show the same correlation. If the metal-poor GCs are part of the early formation of the halo and built up through mergers, then our results support a picture where halo formation and merging occur anisotropically, and that the present-day major axis is an indicator of the preferred merging axis.

  11. Multi-objective availability-redundancy allocation problem for a system with repairable and non-repairable components

    OpenAIRE

    Hossein Zoulfaghari; Ali Zeinal Hamadani; Mostafa Abouei Ardakan

    2015-01-01

    Reliability is one of the most important characteristics of the electrical and mechanical systems with applications in the space communication industries, internet networks, telecommunication systems, power generation systems, and productive facilities. What adds to the importance of reliability in these systems are system complications, nature of competitive markets, and increasing production costs due to failures. This paper investigates availability optimization of a system using both repa...

  12. Cluster bomb ocular injuries

    Directory of Open Access Journals (Sweden)

    Ahmad M Mansour

    2012-01-01

    Full Text Available Purpose: To present the visual outcomes and ocular sequelae of victims of cluster bombs. Materials and Methods: This retrospective, multicenter case series of ocular injury due to cluster bombs was conducted for 3 years after the war in South Lebanon (July 2006. Data were gathered from the reports to the Information Management System for Mine Action. Results: There were 308 victims of clusters bombs; 36 individuals were killed, of which 2 received ocular lacerations and; 272 individuals were injured with 18 receiving ocular injury. These 18 surviving individuals were assessed by the authors. Ocular injury occurred in 6.5% (20/308 of cluster bomb victims. Trauma to multiple organs occurred in 12 of 18 cases (67% with ocular injury. Ocular findings included corneal or scleral lacerations (16 eyes, corneal foreign bodies (9 eyes, corneal decompensation (2 eyes, ruptured cataract (6 eyes, and intravitreal foreign bodies (10 eyes. The corneas of one patient had extreme attenuation of the endothelium. Conclusions: Ocular injury occurred in 6.5% of cluster bomb victims and 67% of the patients with ocular injury sustained trauma to multiple organs. Visual morbidity in civilians is an additional reason for a global ban on the use of cluster bombs.

  13. Dynamic availability assessment and optimal component design of multi-state weighted k-out-of-n systems

    International Nuclear Information System (INIS)

    Availability/reliability is a main feature of design and operation of all engineering systems. Recently, availability evaluation of multi-state systems with different structures is at the center of attention due to the wide applications in engineering. In this paper, a dynamic model is developed for the availability assessment of multi-state weighted k-out-of-n systems. Then, in a design optimization problem, the availability and capacity for the components of such systems are optimized by genetic algorithm. In the dynamic model, the probabilities and capacities of components in different states are allowed to be changed over time. For availability assessment, universal generating function and Markov process are adopted. Application of the proposed model is illustrated using a real-world marine transportation system in order to evaluate and compare the presented optimization problems in assessing system availability. - Highlights: • A dynamic availability model is developed for multi-state weighted k-out-of-n systems. • Optimization problems for the design of multi-state weighted k-out-of-n systems are formulized based on the dynamic availability model. • Dynamic optimal design is not necessarily only one best solution during the time

  14. The thermal conductivity of clustered nanocolloids

    Directory of Open Access Journals (Sweden)

    Saba Lotfizadeh

    2014-06-01

    Full Text Available We quantify the effect of clustering on the thermal conductivity of colloidal dispersions using silane-treated silica, a system engineered to exhibit reversible clustering under well-controlled conditions. We show that the thermal conductivity increases monotonically with cluster size and spans the entire range between the two limits of Maxwell's theory. The results, corroborated by numerical simulation, demonstrate that large increases of the thermal conductivity of colloidal dispersions are possible, yet fully within the predictions of classical theory.

  15. 68 FR 2278 - Commercial Availability of Navigation Devices; Compatibility Between Cable Systems and Consumer...

    Science.gov (United States)

    2003-01-16

    ...), 65 FR 58255, September 28, 2000. In its Compatibility Between Cable Systems and Consumer Electronics.... See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121 (1998). 9. Comments filed... Systems and Consumer Electronics Equipment AGENCY: Federal Communications Commission. ACTION:...

  16. Phosphate availability in the soil-root system: integration of oxide surface chemistry, transport and uptake.

    NARCIS (Netherlands)

    Geelhoed, J.S.

    1998-01-01

    A study is presented on the adsorption of phosphate on goethite, the interaction of phosphate with other adsorbing ions at the goethite surface, and the resulting availability of phosphate to plants. The plant-availability of sorbed phosphate was determined from phosphorus uptake of plants growing o

  17. Performance validation of commercially available mobile waste-assay systems: Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Schanfein, M.; Bonner, C.; Maez, R. [Los Alamos National Lab., NM (United States)] [and others

    1997-11-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems` performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system`s performance for specific waste types, the standardized systems` performance be evaluated. 7 figs., 11 tabs.

  18. A survey of commercially available manipulators, end-effectors, and delivery systems for reactor decommissioning activities

    International Nuclear Information System (INIS)

    Numerous nuclear facilities owned by the U.S. Department of Energy (DOE) are under consideration for decommissioning. Currently, there are no standardized, automated, remote systems designed to dismantle and thereby reduce the size of activated reactor components and vessels so that they can be packaged and shipped to disposal sites. Existing dismantling systems usually consist of customized, facility-specific tooling that has been developed to dismantle a specific reactor system. Such systems have a number of drawbacks. Generally, current systems cannot be disassembled, moved, and reused. Developing and deploying the tooling for current systems is expensive and time-consuming. In addition, the amount of manual work is significant because long-handled tools must be used; as a result, personnel are exposed to excessive radiation. A standardized, automated, remote system is therefore needed to deliver the tooling necessary to dismantle nuclear facilities at different locations. Because this system would be reusable, it would produce less waste. The system would also save money because of its universal design, and it would be more reliable than current systems

  19. Maintenance grouping for multi-component systems with availability constraints and limited maintenance teams

    OpenAIRE

    Do Van, Phuc; Vu, Hai Canh; Barros, Anne; Bérenguer, Christophe

    2015-01-01

    The paper deals with a maintenance grouping approach for multi-component systems whose components are connected in series. The considered systems are required to serve a sequence of missions with limited breaks/stoppage durations while maintenance teams (repairmen) are limited and may vary over time. The optimization of the maintenance grouping decision for such multi-component systems leads to a NP-complete problem. The aim of the paper is to propose and to optimize a dynamic maintenance dec...

  20. Performance validation of commercially available mobile waste-assay systems: Preliminary report

    International Nuclear Information System (INIS)

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems' performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims of guaranteeing any system's performance for specific waste types, the standardized systems' performance be evaluated. 7 figs., 11 tabs

  1. Energy optimization model for a CCHP system with available gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Kong, X.Q.; Wang, R.Z.; Huang, X.H. [Shanghai Jiao Tong Univ., Inst. of Refrigeration and Cryogenics, Shanghai (China)

    2005-02-01

    This paper deals with the problem of optimal energy management of cogeneration system for combined cooling, heating and power production (CCHP). The energy system consists of a gas turbine, an absorption chiller and a heat recovery boiler. A simple linear programming model is presented to determine the optimal strategies that minimize the overall cost of energy for the CCHP system. It is shown that the optimal operation of this system is dependent upon load conditions to be satisfied. In view of energy cost, it is shown that sometimes it may not be optimal to operate the turbine. This is the case when the electric-to-gas cost ratio is very low. (Author)

  2. Satellite power system (SPS). Rectenna siting: availability and distribution of nominally eligible sites

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    Siting of 60 ground receiving stations (rectennas) for the SPS may pose a problem due to the large area per rectenna (15,000 hectares, 38,000 acres) and numerous siting constraints. This study analyzes areas potentially eligible for rectenna sites by mapping, at a national scale, those conditions which would preclude rectenna construction. These exclusion variables which reflect restricted lands, topography, safety, national policy and electromagnetic (microwave) effects, have been computer encoded and tabulated. Subsequent analysis of the nine electric power planning regions that make up the contiguous states indicate an apparently adequate number of nominally eligible sites in all regions in comparison to projected electrical generation. Eligibility in this context means only that areas were not excluded in this national level analysis; more detailed investigation may reveal purely local constraints or smaller scale exclusions. A second major qualification relates to small isolated eligible areas. Eliminating individual eligible clusters with less than nine times the area of one rectenna eliminates much of the Eastern US; a four-to-one adjacent eligible area test poses no such problem. An independant study of the placement of 60 nominal sites in relation to projected load centers reveals that, even with modest transmission distances, the supply of eligible areas is not a key constraint, except perhaps in the Mid-Atlantic (Electric Reliability) Council Region. Even when several less critical (potential) exclusions are considered, more than 19% of the US is eligible; every region except Mid-Atlantic has at least 50 times an many eligible sites as are required.

  3. Multi-objective availability-redundancy allocation problem for a system with repairable and non-repairable components

    Directory of Open Access Journals (Sweden)

    Hossein Zoulfaghari

    2015-07-01

    Full Text Available Reliability is one of the most important characteristics of the electrical and mechanical systems with applications in the space communication industries, internet networks, telecommunication systems, power generation systems, and productive facilities. What adds to the importance of reliability in these systems are system complications, nature of competitive markets, and increasing production costs due to failures. This paper investigates availability optimization of a system using both repairable and non-repairable components, simultaneously. The availability-redundancy allocation problems involve the determination of component availability (i.e., life time and repair time of the components and the redundancy levels that produce maximum system availability. These problems are often subject to some constraints on their components such as cost, weight, and volume. To maximize the availability and to minimize the total cost of the system, a new Mixed Integer Nonlinear Programming (MINLP model is presented. To solve the proposed model, an improved version of the genetic algorithm is designed as an efficient meta-heuristic algorithm. Finally, in order to verify the efficiency of the proposed algorithm, a numerical example of a system is presented that consists of both repairable and non-repairable components.

  4. Heterogeneous clusters as a model system for the study of ionization dynamics within tampered samples

    International Nuclear Information System (INIS)

    Tampering of a sample with a layer of another material is a promising technique to slow down the expansion dynamics within laser irradiated samples, with sound implications for single-particle diffraction imaging. Ideally, if an imaged object is covered by a layer of another material, during the irradiation this layer will be primarily ionized and will expand fast due to Coulomb repulsion, whereas the object located within the net neutral core will expand more slowly (hydrodynamically). We investigate the details of the electronic damage within the tampered samples during their irradiation with an intense extreme ultraviolet (EUV) pulse. We study heterogeneous clusters composed of noble gas atoms, Xe and Ar, for which chemical-bond effects can be neglected. Using a fully nonequilibrium kinetic equation code, we demonstrate the influence of cluster composition on ionization dynamics; in particular, on the electronic damage. The results are obtained for the wavelength of 32 nm, which is available at the free-electron laser in Hamburg (FLASH) facility, but our conclusions can also have implications for samples with a more complex structure and irradiated at a much shorter wavelength.

  5. Understanding resonant tunnel transport in non-identical and non-aligned clusters as applied to disordered carbon systems

    International Nuclear Information System (INIS)

    We study the conductance spectra and the corresponding current-voltage characteristics of a set of three impurity clusters of different sizes arranged in the form of a scalene triangle and compare with the transport of their horizontal and vertical configurations. The tuning capability of resonant tunnelling features in a quantum dot device made of these non-aligned impurity clusters is demonstrated by re-distributing their diameters and inter-cluster distances in a systematic manner. By manipulating the inter-cluster coupling for a scalene triangular configuration, the transition of current-voltage curves from a step-like feature to a negative differential resistance can be produced. This process also yields conductance features for triangular configurations, which can be compared to the quantum dot structures perfectly aligned to the direction of the propagating wavevector. The strength of inter-cluster coupling or order parameter for these configurations is analysed from the relative variation of the width and the energy difference of the sharp and broad peaks observed in the density of states spectra. Based on the relative change of the inter-cluster coupling with the cluster configurations, a transport model applicable to structurally inhomogeneous systems is proposed in order to explain the experimentally observed variation of the energy band gap with the disorder parameters.

  6. Two-stage scheduling algorithm based on priority table for clusters with inaccurate system parameters

    Institute of Scientific and Technical Information of China (English)

    LIU An-feng; CHEN Zhi-gang; XIONG Ce

    2006-01-01

    A new two-stage soft real-time scheduling algorithm based on priority table was proposed for task dispatch and selection in cluster systems with inaccurate parameters. The inaccurate characteristics of the system were modeled through probability analysis. By taking into account the multiple important system parameters, including task deadline, priority, session integrity and memory access locality, the algorithm is expected to achieve high quality of service. Lots of simulation results collected under different load conditions demonstrate that the algorithm can not only effectively overcome the inaccuracy of the system state, but also optimize the task rejected ratio, value realized ratio, differentiated service guaranteed ratio, and session integrity ensured ratio with the average improvement of 3.5%, 5.8%, 7.6% and 5.5%, respectively. Compared with many existing schemes that cannot deal with the inaccurate parameters of the system, the proposed scheme can achieve the best system performance by carefully adjusting scheduling probability. The algorithm is expected to be promising in systems with soft real-time scheduling requirement such as E-commerce applications.

  7. 45 CFR 310.5 - What options are available for Computerized Tribal IV-D Systems and office automation?

    Science.gov (United States)

    2010-10-01

    ... IV-D Systems and office automation? 310.5 Section 310.5 Public Welfare Regulations Relating to Public... AUTOMATION Requirements for Computerized Tribal IV-D Systems and Office Automation § 310.5 What options are available for Computerized Tribal IV-D Systems and office automation? (a) Allowable computerized...

  8. Coexistence between genetically modified, conventional and organic crops. Availability of organically produced seed of varieties adapted to organic production systems

    OpenAIRE

    Boelt, B.; Deleuran, L.C.

    2005-01-01

    To maintain the integrity of organic farming systems guidelines to ensure coexistence between genetically modified (GM), conventional and organic crops should be implied. Since seed is moved cross borders a regulatory system is need to allow for organically produced seed of varieties adapted to organic production systems being available to organic farmers both in developed and developing countries.

  9. MODEL-BASED CLUSTERING FOR CLASSIFICATION OF AQUATIC SYSTEMS AND DIAGNOSIS OF ECOLOGICAL STRESS

    Science.gov (United States)

    Clustering approaches were developed using the classification likelihood, the mixture likelihood, and also using a randomization approach with a model index. Using a clustering approach based on the mixture and classification likelihoods, we have developed an algorithm that...

  10. Assembly and comparison of available solar hot water system reliability databases and information.

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, David F. (Building Specialists, Inc., Albuquerque, NM)

    2009-05-01

    Solar hot water (SHW) systems have been installed commercially for over 30 years, yet few quantitative details are known about their reliability. This report describes a comprehensive analysis of all of the known major previous research and data regarding the reliability of SHW systems and components. Some important conclusions emerged. First, based on a detailed inspection of ten-year-old systems in Florida, about half of active systems can be expected to fail within a ten-year period. Second, valves were identified as the probable cause of a majority of active SHW failures. Third, passive integral and thermosiphon SHW systems have much lower failure rates than active ones, probably due to their simple design that employs few mechanical parts. Fourth, it is probable that the existing data about reliability do not reveal the full extent of fielded system failures because most of the data were based on trouble calls. Often an SHW system owner is not aware of a failure because the backup system silently continues to produce hot water. Thus, a repair event may not be generated in a timely manner, if at all. This final report for the project provides all of the pertinent details about this study, including the source of the data, the techniques to assure their quality before analysis, the organization of the data into perhaps the most comprehensive reliability database in existence, a detailed statistical analysis, and a list of recommendations for additional critical work. Important recommendations include the inclusion of an alarm on SHW systems to identify a failed system, the need for a scientifically designed study to collect high-quality reliability data that will lead to design improvements and lower costs, and accelerated testing of components that are identified as highly problematic.

  11. Unidirectional laning and migrating cluster crystals in confined self-propelled particle systems

    International Nuclear Information System (INIS)

    One standard approach to describe the collective behaviour of self-propelled particles is the Vicsek model: point-like self-propelled particles tend to align their migration directions to the ones of their nearer neighbours at each time-step. Here we use a variant of the Vicsek model that includes pairwise repulsive interactions. Confining the system between parallel walls can qualitatively change its appearance: a laning state can emerge that is different from the ones previously reported. All lanes show on average the same migration direction of the contained particles with a finite separation distance between the lanes. Furthermore, in certain parameter ranges we observe collectively migrating clusters that arrange in an approximately hexagonal way. We suggest that the mechanism behind these regular textures is an overreaction in the alignment mechanism. Considering the more realistic scenario of non-point-like particles in the presence of confining surfaces is generally important for the comparison to experimental systems. (paper)

  12. Iterative solution of general sparse linear systems on clusters of workstations

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Gen-Ching; Saad, Y. [Univ. of Minnesota, Minneapolis, MN (United States)

    1996-12-31

    Solving sparse irregularly structured linear systems on parallel platforms poses several challenges. First, sparsity makes it difficult to exploit data locality, whether in a distributed or shared memory environment. A second, perhaps more serious challenge, is to find efficient ways to precondition the system. Preconditioning techniques which have a large degree of parallelism, such as multicolor SSOR, often have a slower rate of convergence than their sequential counterparts. Finally, a number of other computational kernels such as inner products could ruin any gains gained from parallel speed-ups, and this is especially true on workstation clusters where start-up times may be high. In this paper we discuss these issues and report on our experience with PSPARSLIB, an on-going project for building a library of parallel iterative sparse matrix solvers.

  13. Ubiquity of density slope oscillations in the central regions of galaxy and cluster-sized systems

    Science.gov (United States)

    Young, Anthony M.; Williams, Liliya L. R.; Hjorth, Jens

    2016-05-01

    One usually thinks of a radial density profile as having a monotonically changing logarithmic slope, such as in NFW or Einasto profiles. However, in two different classes of commonly used systems, this is often not the case. These classes exhibit non-monotonic changes in their density profile slopes which we call oscillations for short. We analyze these two unrelated classes separately. Class 1 consists of systems that have density oscillations and that are defined through their distribution function f(E), or differential energy distribution N(E), such as isothermal spheres, King profiles, or DARKexp, a theoretically derived model for relaxed collisionless systems. Systems defined through f(E) or N(E) generally have density slope oscillations. Class 1 system oscillations can be found at small, intermediate, or large radii but we focus on a limited set of Class 1 systems that have oscillations in the central regions, usually at log(r/r‑2) lesssim ‑2, where r‑2 is the largest radius where dlog(ρ)/dlog(r) = ‑2. We show that the shape of their N(E) can roughly predict the amplitude of oscillations. Class 2 systems which are a product of dynamical evolution, consist of observed and simulated galaxies and clusters, and pure dark matter halos. Oscillations in the density profile slope seem pervasive in the central regions of Class 2 systems. We argue that in these systems, slope oscillations are an indication that a system is not fully relaxed. We show that these oscillations can be reproduced by small modifications to N(E) of DARKexp. These affect a small fraction of systems' mass and are confined to log(r/r‑2) lesssim 0. The size of these modifications serves as a potential diagnostic for quantifying how far a system is from being relaxed.

  14. Data availability and the role of the earth resources observation systems data center

    Science.gov (United States)

    Watkins, A. H.

    1975-01-01

    With the launch of LANDSAT-1 in July 1972, and the follow-on launch of LANDSAT-2 in January of this year, routine availability of satellite imagery and electronic data of the earth's resources has become a reality. Federal data centers provide LANDSAT data to resource managers and the general public. These data centers have to date provided almost 500,000 frames of LANDSAT data at a cost of more than $2,000,000. Data from the LANDSAT satellite program, along with data and information from the Skylab manned program, are available over any location to anyone for the cost of reproduction.

  15. AN OVERVIEW ON RECOMMENDATION SYSTEMS AVAILABLE FOR TAXI DRIVERS AND PASSENGERS

    OpenAIRE

    Shaikh Nazneen N.*, Prof. Kahate S.A

    2016-01-01

    We all are using different transportation facility to travel to particular location in our day today life. While traveling from one place to other, as time is changing ,the way we travel is also changing very fast. Like long years ago people used to walk from place to place as that time no vehicles were available. Then after invention of vehicles people atsrted using bus, train, taxi, bike, plane for travelling. Thought there are many options available for travelling in city, most popular is ...

  16. An Efficient Enhanced Clustering Algorithm of Information System For Law Enforcement

    OpenAIRE

    Dr. A. Malathi; Dr. P. Rajarajeswari

    2014-01-01

    Clustering is a popular data mining techniques which is intended to help the user discover and understand the structure or grouping of the data in the set according to a certain similarity measure and predict future structure or group respectively. Clustering is the process of class discovery, where the objects are grouped into clusters. In this paper Enhanced K-Means and Enhanced DBSCAN algorithms are designed and used for the clustering crime data in the proposed crime analysis tool. Anothe...

  17. Explaining the Color Distributions of Globular Cluster Systems in Elliptical Galaxies

    OpenAIRE

    Yoon, Suk-Jin; Yi, Sukyoung Ken; Lee, Young-Wook

    2006-01-01

    The colors of globular clusters in most of large elliptical galaxies are bimodal. This is generally taken as evidence for the presence of two cluster subpopulations that have different geneses. However, here we find that, because of the non-linear nature of the metallicity-to-color transformation, a coeval group of old clusters with a unimodal metallicity spread can exhibit color bimodality. The models of cluster colors indicate that the horizontal-branch stars are the main drivers behind the...

  18. Cluster-shell competition in systems with a few alpha particles and valence neutrons

    International Nuclear Information System (INIS)

    We construct nuclear wave functions from alpha clusters and some additional valence nucleons, and allow the inter-cluster distance to change and one alpha to dissolve from the (0s)4 structure as a result of the nuclear interaction. The change of the inter-cluster distance and the dissolution of the alpha particle can be interpreted as resulting from the competition of the 'shell model' and 'cluster model'. We demonstrate this competition through a few parameters.

  19. Availability verification of information for human system interface in automatic SG level control using activity diagram

    International Nuclear Information System (INIS)

    Steam Generator (SG) level control system in OPR 1000 is one of representative automatic systems that falls under the Supervisory Control level in Endsley's taxonomy. Supervisory control of automated systems is classified as a form of out of the loop (OOTL) performance due to passive involvement in the systems operation, which could lead to loss of situation awareness (SA). There was a reported event, which was caused by inadequate human automation communication that contributed to an unexpected reactor trip in July 2005. A high SG level trip occurred in Yeonggwang (YGN) Unit 6 Nuclear Power Plant (NPP) due to human operator failure to recognize the need to change the control mode of the economizer valve controller (EVC) to manual mode during swap over (the transition from low power mode to high power mode) after the loss of offsite power (LOOP) event was recovered. This paper models the human system interaction in NPP SG level control system using Unified Modeling Language (UML) Activity Diagram. Then, it identifies the missing information for operators in the OPR1000 Main Control Room (MCR) and suggests some means of improving the human system interaction

  20. Performance validation of commercially available mobile waste-assay systems: Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Schanfein, M.; Bonner, C.; Maez, R. [and others

    1997-08-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content to reduce the radioactive hazard to the public. Validation of the waste-assay systems` performance is critical for establishing the credibility of the assay results for storage and disposal purposes. Canberra Nuclear has evaluated regulations worldwide and identified standard, modular, neutron- and gamma-waste-assay systems that can be used to characterize a large portion of existing and newly generated transuranic (TRU) and low-level waste. Before making claims or guaranteeing any system`s performance for specific waste types, the standardized systems` performance must be evaluated. Canberra and Los Alamos National Laboratory`s (LANL) Plutonium Facility developed a three-phase validation plan. During Phase One, tests were performed using simulation sources at Canberra to determine the error bounds for measurement parameters, to determine the minimum detectable activity, and to measure precision and bias. During Phase Two, two mobile systems were installed at the Plutonium Facility. LANL is providing peer review of the systems` performance for plutonium, acting as a beta test site to evaluate the waste-assay software, and providing data for {open_quotes}precertification{close_quotes} at future Department of Energy installations. (Plutonium isotopics are determined from measurements using the Multi-Group Analysis code.) Finally, the two systems` performances are evaluated for representative waste types (salt, metal, combustibles, leaded rubber, and HEPA filters). Phase Three of the validation, the Waste Isolation Pilot Plant Performance Demonstration Plan, will require approval by the National TRU Program Office. This paper describes the standard mobile waste-assay systems, the test plan, and preliminary results from the peer review outlined above in Phase Two.