Science.gov

Sample records for hierarchical multiple system

  1. Observations of Hierarchical Solar-type Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Roberts, Lewis C., Jr.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Riddle, Reed L.

    2015-10-01

    Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible Robo-AO system with new near-infrared observations with PALM-3000. The physical status of most, but not all, of the new pairs is confirmed by photometry in the Ks band and new positional measurements. In addition, we resolved for the first time five close sub-systems: the known astrometric binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP 118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We place the components on a color-magnitude diagram and discuss each multiple system individually.

  2. OBSERVATIONS OF HIERARCHICAL SOLAR-TYPE MULTIPLE STAR SYSTEMS

    SciTech Connect

    Roberts, Lewis C. Jr.; Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.; Riddle, Reed L.

    2015-10-15

    Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible Robo-AO system with new near-infrared observations with PALM-3000. The physical status of most, but not all, of the new pairs is confirmed by photometry in the Ks band and new positional measurements. In addition, we resolved for the first time five close sub-systems: the known astrometric binary in HIP 17129AB, companions to the primaries of HIP 33555, and HIP 118213, and the companions to the secondaries in HIP 25300 and HIP 101430. We place the components on a color–magnitude diagram and discuss each multiple system individually.

  3. Hierarchical multilevel authentication system for multiple-image based on phase retrieval and basic vector operations

    NASA Astrophysics Data System (ADS)

    Li, Xianye; Meng, Xiangfeng; Yin, Yongkai; Yang, Xiulun; Wang, Yurong; Peng, Xiang; He, Wenqi; Pan, Xuemei; Dong, Guoyan; Chen, Hongyi

    2017-02-01

    A hierarchical multilevel authentication system for multiple-image based on phase retrieval and basic vector operations in the Fresnel domain is proposed, by which more certification images are iteratively encoded into multiple cascaded phase masks according to different hierarchical levels. Based on the secret sharing algorithm by basic vector decomposition and composition operations, the iterated phase distributions are split into n pairs of shadow images keys (SIKs), and then distributed to n different participants (the authenticators). During each level in the high authentication process, any 2 or more participants can be gathered to reconstruct the original meaningful certification images. While in the case of each level in the low authentication process, only one authenticator who possesses a correct pair of SIKs, will gain no significant information of certification image; however, it can result in a remarkable peak output in the nonlinear correlation coefficient of the recovered image and the standard certification image, which can successfully provide an additional authentication layer for the high-level authentication. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method.

  4. Continued Kinematic and Photometric Investigations of Hierarchical Solar-type Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Roberts, Lewis C., Jr.; Tokovinin, Andrei; Mason, Brian D.; Marinan, Anne D.

    2017-03-01

    We observed 15 of the solar-type binaries within 67 pc of the Sun previously observed by the Robo-AO system in the visible, with the PHARO near-infrared camera and the PALM-3000 adaptive optics system on the 5 m Hale telescope. The physical status of the binaries is confirmed through common proper motion and detection of orbital motion. In the process, we detected a new candidate companion to HIP 95309. We also resolved the primary of HIP 110626 into a close binary, making that system a triple. These detections increase the completeness of the multiplicity survey of the solar-type stars within 67 pc of the Sun. Combining our observations of HIP 103455 with archival astrometric measurements and RV measurements, we are able to compute the first orbit of HIP 103455, showing that the binary has a 68 year period. We place the components on a color–magnitude diagram and discuss each multiple system individually.

  5. Explosive Outflows Powered by the Decay of Non-hierarchical Multiple Systems of Massive Stars: Orion BN/KL

    NASA Astrophysics Data System (ADS)

    Bally, John; Cunningham, Nathaniel J.; Moeckel, Nickolas; Burton, Michael G.; Smith, Nathan; Frank, Adam; Nordlund, Ake

    2011-02-01

    The explosive Becklin-Neugebauer (BN)/Kleinman-Low (KL) outflow emerging from OMC1 behind the Orion Nebula may have been powered by the dynamical decay of a non-hierarchical multiple system ~500 years ago that ejected the massive stars I, BN, and source n, with velocities of about 10-30 km s-1. New proper-motion measurements of H2 features show that within the errors of measurement, the outflow originated from the site of stellar ejection. Combined with published data, these measurements indicate an outflow age of ~500 years, similar to the time since stellar ejection. The total kinetic energy of the ejected stars and the outflow is about 2 to 6 × 1047 erg. It is proposed that the gravitational potential energy released by the formation of a short-period binary, most likely source I, resulted in stellar ejection and powered the outflow. A scenario is presented for the formation of a compact, non-hierarchical multiple star system, its decay into an ejected binary and two high-velocity stars, and launch of the outflow. Three mechanisms may have contributed to the explosion in the gas: (1) unbinding of the circumcluster envelope following stellar ejection, (2) disruption of circumstellar disks and high-speed expulsion of the resulting debris during the final stellar encounter, and (3) the release of stored magnetic energy. Plausible protostellar disk end envelope properties can produce the observed outflow mass, velocity, and kinetic energy distributions. The ejected stars may have acquired new disks by fall-back or Bondi-Hoyle accretion with axes roughly orthogonal to their velocities. The expulsion of gas and stars from OMC1 may have been driven by stellar interactions.

  6. EXPLOSIVE OUTFLOWS POWERED BY THE DECAY OF NON-HIERARCHICAL MULTIPLE SYSTEMS OF MASSIVE STARS: ORION BN/KL

    SciTech Connect

    Bally, John; Cunningham, Nathaniel J.; Moeckel, Nickolas; Burton, Michael G.; Smith, Nathan; Frank, Adam; Nordlund, Ake E-mail: ncunningham2@unl.edu E-mail: mgb@phys.unsw.edu.au E-mail: afrank@pas.rochester.edu

    2011-02-01

    The explosive Becklin-Neugebauer (BN)/Kleinman-Low (KL) outflow emerging from OMC1 behind the Orion Nebula may have been powered by the dynamical decay of a non-hierarchical multiple system {approx}500 years ago that ejected the massive stars I, BN, and source n, with velocities of about 10-30 km s{sup -1}. New proper-motion measurements of H{sub 2} features show that within the errors of measurement, the outflow originated from the site of stellar ejection. Combined with published data, these measurements indicate an outflow age of {approx}500 years, similar to the time since stellar ejection. The total kinetic energy of the ejected stars and the outflow is about 2 to 6 x 10{sup 47} erg. It is proposed that the gravitational potential energy released by the formation of a short-period binary, most likely source I, resulted in stellar ejection and powered the outflow. A scenario is presented for the formation of a compact, non-hierarchical multiple star system, its decay into an ejected binary and two high-velocity stars, and launch of the outflow. Three mechanisms may have contributed to the explosion in the gas: (1) unbinding of the circumcluster envelope following stellar ejection, (2) disruption of circumstellar disks and high-speed expulsion of the resulting debris during the final stellar encounter, and (3) the release of stored magnetic energy. Plausible protostellar disk end envelope properties can produce the observed outflow mass, velocity, and kinetic energy distributions. The ejected stars may have acquired new disks by fall-back or Bondi-Hoyle accretion with axes roughly orthogonal to their velocities. The expulsion of gas and stars from OMC1 may have been driven by stellar interactions.

  7. HDS: Hierarchical Data System

    NASA Astrophysics Data System (ADS)

    Pearce, Dave; Walter, Anton; Lupton, W. F.; Warren-Smith, Rodney F.; Lawden, Mike; McIlwrath, Brian; Peden, J. C. M.; Jenness, Tim; Draper, Peter W.

    2015-02-01

    The Hierarchical Data System (HDS) is a file-based hierarchical data system designed for the storage of a wide variety of information. It is particularly suited to the storage of large multi-dimensional arrays (with their ancillary data) where efficient access is needed. It is a key component of the Starlink software collection (ascl:1110.012) and is used by the Starlink N-Dimensional Data Format (NDF) library (ascl:1411.023). HDS organizes data into hierarchies, broadly similar to the directory structure of a hierarchical filing system, but contained within a single HDS container file. The structures stored in these files are self-describing and flexible; HDS supports modification and extension of structures previously created, as well as functions such as deletion, copying, and renaming. All information stored in HDS files is portable between the machines on which HDS is implemented. Thus, there are no format conversion problems when moving between machines. HDS can write files in a private binary format (version 4), or be layered on top of HDF5 (version 5).

  8. HDS -- Hierarchical Data System

    NASA Astrophysics Data System (ADS)

    Warren-Smith, R. F.; Lawden, M. D.; McIlwrath, B. K.; Jenness, T.; Draper, P. W., Peden, J. C. M.

    HDS is a file-based hierarchical data system designed for the storage of a wide variety of information. It is particularly suited to the storage of large multi-dimensional arrays (with their ancillary data) where efficient access is needed. HDS organises data into hierarchies, broadly similar to the directory structure of a hierarchical filing system, but contained within a single HDS container file. The structures stored in these files are self-describing and flexible; HDS supports modification and extension of structures previously created, as well as deletion, copying, renaming, etc. All information stored in HDS files is portable between the machines on which HDS is implemented. Thus, there are no format conversion problems when moving between machines. The routines described in this document may be used to perform operations on any HDS data. In addition, HDS forms a toolkit for the construction of higher level (more specialised) data structures and the software which accesses them. HDS routines are therefore invoked indirectly by many other items of Starlink software.

  9. Multiple sequence alignment with hierarchical clustering.

    PubMed Central

    Corpet, F

    1988-01-01

    An algorithm is presented for the multiple alignment of sequences, either proteins or nucleic acids, that is both accurate and easy to use on microcomputers. The approach is based on the conventional dynamic-programming method of pairwise alignment. Initially, a hierarchical clustering of the sequences is performed using the matrix of the pairwise alignment scores. The closest sequences are aligned creating groups of aligned sequences. Then close groups are aligned until all sequences are aligned in one group. The pairwise alignments included in the multiple alignment form a new matrix that is used to produce a hierarchical clustering. If it is different from the first one, iteration of the process can be performed. The method is illustrated by an example: a global alignment of 39 sequences of cytochrome c. PMID:2849754

  10. Hierarchical group testing for multiple infections

    PubMed Central

    Hou, Peijie; Tebbs, Joshua M.; Bilder, Christopher R.; McMahan, Christopher S.

    2016-01-01

    Summary Group testing, where individuals are tested initially in pools, is widely used to screen a large number of individuals for rare diseases. Triggered by the recent development of assays that detect multiple infections at once, screening programs now involve testing individuals in pools for multiple infections simultaneously. Tebbs, McMahan, and Bilder (2013, Biometrics) recently evaluated the performance of a two-stage hierarchical algorithm used to screen for chlamydia and gonorrhea as part of the Infertility Prevention Project in the United States. In this article, we generalize this work to accommodate a larger number of stages. To derive the operating characteristics of higher-stage hierarchical algorithms with more than one infection, we view the pool decoding process as a time-inhomogeneous, finite-state Markov chain. Taking this conceptualization enables us to derive closed-form expressions for the expected number of tests and classification accuracy rates in terms of transition probability matrices. When applied to chlamydia and gonorrhea testing data from four states (Region X of the United States Department of Health and Human Services), higher-stage hierarchical algorithms provide, on average, an estimated 11 percent reduction in the number of tests when compared to two-stage algorithms. For applications with rarer infections, we show theoretically that this percentage reduction can be much larger. PMID:27657666

  11. Hierarchical-genetic-algorithm-based design of a large scale Fresnel lens for a reading light system with multiple LED sources.

    PubMed

    Chen, Wen-Gong; Uang, Chii-Maw

    2006-10-20

    A conventional Fresnel lens is suitable to be used in the reading light system due to its features of directing and collecting light rays, as well as its properties of being essentially flat, plastic, lightweight, and cost efficient. However, it is not suitable for a reading light system with multiple light sources. To a reading light system with multiple light sources, a Fresnel lens with suitably designed groove angles can be used to improve the performance of that system in both illuminance and uniformity. Nevertheless, suitable groove angles are rather difficult to find if a Fresnel lens consists of a lot of groove angles and each angle covers a wide range of degrees. We develop a hierarchical genetic algorithm (HGA) to search for a set of optimal groove angles to design a Fresnel lens for a reading light system with multiple light sources from an enormous searching space. In addition, the groove angles of the Fresnel lens are directly derived from a conventional Fresnel lens database. The design goal is to maximize the illuminance and simultaneously maintain the uniformity of light rays incident to a specified reading surface. As a result, we can demonstrate that a HGA really works better than a genetic algorithm and the optimally designed Fresnel lens, indeed, offers a better light-guiding performance than a conventional Fresnel lens for a multiple-LED reading light system.

  12. Hierarchical storage management system evaluation

    NASA Technical Reports Server (NTRS)

    Woodrow, Thomas S.

    1993-01-01

    The Numerical Aerodynamic Simulation (NAS) Program at NASA Ames Research Center has been developing a hierarchical storage management system, NAStore, for some 6 years. This evaluation compares functionality, performance, reliability, and other factors of NAStore and three commercial alternatives. FileServ is found to be slightly better overall than NAStore and DMF. UniTree is found to be severely lacking in comparison.

  13. Hierarchical structure of biological systems

    PubMed Central

    Alcocer-Cuarón, Carlos; Rivera, Ana L; Castaño, Victor M

    2014-01-01

    A general theory of biological systems, based on few fundamental propositions, allows a generalization of both Wierner and Berthalanffy approaches to theoretical biology. Here, a biological system is defined as a set of self-organized, differentiated elements that interact pair-wise through various networks and media, isolated from other sets by boundaries. Their relation to other systems can be described as a closed loop in a steady-state, which leads to a hierarchical structure and functioning of the biological system. Our thermodynamical approach of hierarchical character can be applied to biological systems of varying sizes through some general principles, based on the exchange of energy information and/or mass from and within the systems. PMID:24145961

  14. Personality Traits: Hierarchically Organized Systems.

    PubMed

    Fajkowska, Małgorzata

    2017-03-13

    Personality science has always been and is still ready for new theorizing on traits. Accordingly, this paper presents the recently proposed Traits as Hierarchical Systems (THS) model, where personality traits are not only the emergent properties of the three-level hierarchy of the personality system, but are also hierarchical per se. As hierarchical systems, they are organized into three levels: mechanisms and processes, structures, and behavioral markers. In this approach trait denotes the underlying, recurrent mechanisms that pattern its structure and account for the stability/variability of individual characteristics. Here, traits might be described as processes with a slow rate of change that can be substituted for structure. The main function of personality traits, within the personality system, is stimulation processing. Three dominant functions of stimulation processing in traits are proposed: reactive, regulative, and self-regulative. Some important questions regarding the concept of trait remain, e.g. concerning trait stability, determinacy, measurement, their relation to overt behaviors, personality type or state, differentiation between temperament traits and other-than-temperament personality traits. All of these topics are discussed in this paper, as well as the compatible and distinctive features of this approach in relation to selected, modern trait theories. This article is protected by copyright. All rights reserved.

  15. Hierarchical Robot Control System and Method for Controlling Select Degrees of Freedom of an Object Using Multiple Manipulators

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)

    2013-01-01

    A robotic system includes a robot having manipulators for grasping an object using one of a plurality of grasp types during a primary task, and a controller. The controller controls the manipulators during the primary task using a multiple-task control hierarchy, and automatically parameterizes the internal forces of the system for each grasp type in response to an input signal. The primary task is defined at an object-level of control, e.g., using a closed-chain transformation, such that only select degrees of freedom are commanded for the object. A control system for the robotic system has a host machine and algorithm for controlling the manipulators using the above hierarchy. A method for controlling the system includes receiving and processing the input signal using the host machine, including defining the primary task at the object-level of control, e.g., using a closed-chain definition, and parameterizing the internal forces for each of grasp type.

  16. Hierarchical simulation of large system

    NASA Technical Reports Server (NTRS)

    Saab, Daniel G.

    1991-01-01

    The main problem facing current CAD tools for VLSIs is the large amount of memory required when dealing with large systems, primarily due to the circuit representation used by most current tools. This paper discusses an approach for hierarchical switch-level simulation of digital circuits. The approach exploits the hierarchy to reduce the memory requirements of the simulation, allowing the simulation of circuits that are too large to simulate at one flat level. The approach has been implemented in a hierarchical switch-level simulator, CHAMP, which runs on a SUN workstation. The program performs mixed mode simulation: parts of the circuit can be simulated faster at a behavioral level by supplying a high level software description. CHAMP allows assignable delays, and bidirectional signal flow inside circuit blocks that are represented as transistor networks as well as across the boundaries of higher level blocks. CHAMP is also unique in that it simulates directly from the hierarchical circuit description without flattening to a single level.

  17. Vibrational properties of hierarchical systems

    NASA Astrophysics Data System (ADS)

    Keirstead, W. P.; Ceccatto, H. A.; Huberman, B. A.

    1988-11-01

    The vibrational properties of one-dimensional hierarchical systems are investigated and results are obtained for both their eigenvalues and eigenvectors. Two cases are considered, the first one with a hierarchy of spring constants and the latter with a hierarchy in the masses. In both cases the eigenspectrum is found to be a zero-measure, two-scale Cantor set with a fractal dimension between 0 and 1. The scaling properties of the spectra are calculated using renormalization group techniques and are verified by extensive numerical work. The low-frequency density of states and low-temperature specific heat are calculated and a singularity is found in the scaling behavior. The eigenvectors are found to be either extended or critical and self-similar. A transfer matrix formalism is introduced to calculate the scaling properties of the envelope of the critical eigenvectors. Furthermore, a connection is established between the hierarchical vibration and diffusion problems, as well as to the same problems in random systems, thus showing the universality of the observed features.

  18. Multiple Comparisons in Genetic Association Studies: A Hierarchical Modeling Approach

    PubMed Central

    Yi, Nengjun; Xu, Shizhong; Lou, Xiang-Yang; Mallick, Himel

    2016-01-01

    Multiple comparisons or multiple testing has been viewed as a thorny issue in genetic association studies aiming to detect disease-associated genetic variants from a large number of genotyped variants. We alleviate the problem of multiple comparisons by proposing a hierarchical modeling approach that is fundamentally different from the existing methods. The proposed hierarchical models simultaneously fit as many variables as possible and shrink unimportant effects towards zero. Thus, the hierarchical models yield more efficient estimates of parameters than the traditional methods that analyze genetic variants separately, and also coherently address the multiple comparisons problem due to largely reducing the effective number of genetic effects and the number of statistically ‘significant’ effects. We develop a method for computing the effective number of genetic effects in hierarchical generalized linear models, and propose a new adjustment for multiple comparisons, the hierarchical Bonferroni correction, based on the effective number of genetic effects. Our approach not only increases the power to detect disease-associated variants but also controls the Type I error. We illustrate and evaluate our method with real and simulated data sets from genetic association studies. The method has been implemented in our freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). PMID:24259248

  19. Multiple comparisons in genetic association studies: a hierarchical modeling approach.

    PubMed

    Yi, Nengjun; Xu, Shizhong; Lou, Xiang-Yang; Mallick, Himel

    2014-02-01

    Multiple comparisons or multiple testing has been viewed as a thorny issue in genetic association studies aiming to detect disease-associated genetic variants from a large number of genotyped variants. We alleviate the problem of multiple comparisons by proposing a hierarchical modeling approach that is fundamentally different from the existing methods. The proposed hierarchical models simultaneously fit as many variables as possible and shrink unimportant effects towards zero. Thus, the hierarchical models yield more efficient estimates of parameters than the traditional methods that analyze genetic variants separately, and also coherently address the multiple comparisons problem due to largely reducing the effective number of genetic effects and the number of statistically "significant" effects. We develop a method for computing the effective number of genetic effects in hierarchical generalized linear models, and propose a new adjustment for multiple comparisons, the hierarchical Bonferroni correction, based on the effective number of genetic effects. Our approach not only increases the power to detect disease-associated variants but also controls the Type I error. We illustrate and evaluate our method with real and simulated data sets from genetic association studies. The method has been implemented in our freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/).

  20. How do stakeholders from multiple hierarchical levels of a large provincial health system define engagement? A qualitative study.

    PubMed

    Norris, Jill M; White, Deborah E; Nowell, Lorelli; Mrklas, Kelly; Stelfox, Henry T

    2017-08-01

    Engaging stakeholders from varied organizational levels is essential to successful healthcare quality improvement. However, engagement has been hard to achieve and to measure across diverse stakeholders. Further, current implementation science models provide little clarity about what engagement means, despite its importance. The aim of this study was to understand how stakeholders of healthcare improvement initiatives defined engagement. Participants (n = 86) in this qualitative thematic study were purposively sampled for individual interviews. Participants included leaders, core members, frontline clinicians, support personnel, and other stakeholders of Strategic Clinical Networks in Alberta Health Services, a Canadian provincial health system with over 108,000 employees. We used an iterative thematic approach to analyze participants' responses to the question, "How do you define engagement?" Regardless of their organizational role, participants defined engagement through three interrelated themes. First, engagement was active participation from willing and committed stakeholders, with levels that ranged from information sharing to full decision-making. Second, engagement centered on a shared decision-making process about meaningful change for everyone "around the table," those who are most impacted. Third, engagement was two-way interactions that began early in the change process, where exchanges were respectful and all stakeholders felt heard and understood. This study highlights the commonalities of how stakeholders in a large healthcare system defined engagement-a shared understanding and terminology-to guide and improve stakeholder engagement. Overall, engagement was an active and committed decision-making about a meaningful problem through respectful interactions and dialog where everyone's voice is considered. Our results may be used in conjunction with current implementation models to provide clarity about what engagement means and how to engage various

  1. Hierarchical regression for epidemiologic analyses of multiple exposures

    SciTech Connect

    Greenland, S.

    1994-11-01

    Many epidemiologic investigations are designed to study the effects of multiple exposures. Most of these studies are analyzed either by fitting a risk-regression model with all exposures forced in the model, or by using a preliminary-testing algorithm, such as stepwise regression, to produce a smaller model. Research indicates that hierarchical modeling methods can outperform these conventional approaches. These methods are reviewed and compared to two hierarchical methods, empirical-Bayes regression and a variant here called {open_quotes}semi-Bayes{close_quotes} regression, to full-model maximum likelihood and to model reduction by preliminary testing. The performance of the methods in a problem of predicting neonatal-mortality rates are compared. Based on the literature to date, it is suggested that hierarchical methods should become part of the standard approaches to multiple-exposure studies. 35 refs., 1 fig., 1 tab.

  2. Hierarchical Models of the Nearshore Complex System

    DTIC Science & Technology

    2004-01-01

    unclassified unclassified /,andard Form 7 7Qien. -pii Prescrbed by ANS Sid 239-18 zgB -10z Hierarchical Models of the Nearshore Complex System: Final...TITLE AND SUBTITLE S. FUNDING NUMBERS Hierarchical Models of the Nearshore Complex System N00014-02-1-0358 6. AUTHOR(S) Brad Werner 7. PERFORMING...8217 ........... The long-term goal of this reasearch was to develop and test predictive models for nearshore processes. This grant was terminaton funding for the

  3. Secular Evolution of Hierarchical Planetary Systems

    NASA Astrophysics Data System (ADS)

    Lee, Man Hoi; Peale, S. J.

    2003-08-01

    We investigate the dynamical evolution of coplanar, hierarchical, two-planet systems where the ratio of the orbital semimajor axes α=a1/a2 is small. Hierarchical two-planet systems are likely to be ubiquitous among extrasolar planetary systems. We show that the orbital parameters obtained from a multiple-Kepler fit to the radial velocity variations of a host star are best interpreted as Jacobi coordinates and that Jacobi coordinates should be used in any analyses of hierarchical planetary systems. An approximate theory that can be applied to coplanar, hierarchical, two-planet systems with a wide range of masses and orbital eccentricities is the octopole-level secular perturbation theory, which is based on an expansion to order α3 and orbit averaging. It reduces the coplanar problem to 1 degree of freedom, with e1 (or e2) and ϖ1-ϖ2 as the relevant phase-space variables (where e1,2 are the orbital eccentricities of the inner and outer orbits, respectively, and ϖ1,2 are the longitudes of periapse). The octopole equations show that if the ratio of the maximum orbital angular momenta, λ=L1/L2~(m1/m2)α1/2, for given semimajor axes is approximately equal to a critical value λcrit, then libration of ϖ1-ϖ2 about either 0° or 180° is almost certain, with possibly large amplitude variations of both eccentricities. From a study of the HD 168443 and HD 12661 systems and their variants using both the octopole theory and direct numerical orbit integrations, we establish that the octopole theory is highly accurate for systems with α<~0.1 and reasonably accurate even for systems with α as large as 1/3, provided that α is not too close to a significant mean-motion commensurability or above the stability boundary. The HD 168443 system is not in a secular resonance, and its ϖ1-ϖ2 circulates. The HD 12661 system is the first extrasolar planetary system found to have ϖ1-ϖ2 librating about 180°. The secular resonance means that the lines of apsides of the two orbits

  4. Analysis hierarchical model for discrete event systems

    NASA Astrophysics Data System (ADS)

    Ciortea, E. M.

    2015-11-01

    The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.

  5. Hierarchical and multiple hand action representation using temporal postural synergies.

    PubMed

    Tessitore, G; Sinigaglia, C; Prevete, R

    2013-03-01

    The notion of synergy enables one to provide simplified descriptions of hand actions. It has been used in a number of different meanings ranging from kinematic and dynamic synergies to postural and temporal postural synergies. However, relatively little is known about how representing an action by synergies might take into account the possibility to have a hierarchical and multiple action representation. This is a key aspect for action representation as it has been characterized by action theorists and cognitive neuroscientists. Thus, the aim of the present paper is to investigate whether and to what extent a hierarchical and multiple action representation can be obtained by a synergy approach. To this purpose, we took advantage of representing hand action as a linear combination of temporal postural synergies (TPSs), but on the assumption that TPSs have a tree-structured organization. In a tree-structured organization, a hand action representation can involve a TPS only if the ancestors of the synergy in the tree are themselves involved in the action representation. The results showed that this organization is enough to force a multiple representation of hand actions in terms of synergies which are hierarchically organized.

  6. The complexity of hierarchical systems

    NASA Astrophysics Data System (ADS)

    Ceccatto, H. A.; Huberman, B. A.

    1988-01-01

    We introduce a procedure for coarse graining a given hierarchical structure and show how it leads to an effective saturation of the complexity value with increasing number of lower levels. Secondly, we verify that this coarse grained measure has the property of isolating the most diverse trees as the ones with maximal complexity. As a corollary, we cast the dynamical measure of complexity of Bachas and Huberman in terms of purely static properties of trees representing ultradiffusion. We also discuss the differences between the coarse-grained measure of complexity and that provided by relaxation processes.

  7. Quantum states of hierarchical systems

    NASA Astrophysics Data System (ADS)

    Ceccatto, H. A.; Keirstead, W. P.; Huberman, B. A.

    1987-12-01

    The quantum states of an electron in a hierarchical potential are investigated in the tight-binding approximation. The hierarchy is taken to be in the transition matrix elements, in natural analogy to the classical problem of diffusion in ultrametric structures. The energy spectrum is found to be a Cantor set, and analytical results are presented for its scaling properties. The envelope of the wave function is found to decay algebraically for certain energies and to be constant for others. The results are in excellent agreement with high-precision numerical work.

  8. Hierarchical Docking of Databases of Multiple Ligand Conformations

    PubMed Central

    Lorber, David M.; Shoichet, Brian K.

    2006-01-01

    Ligand flexibility is an important problem in molecular docking and virtual screening. To address this challenge, we investigate a hierarchical pre-organization of multiple conformations of small molecules. Such organization of pre-calculated conformations removes the exploration of ligand conformational space from the docking calculation and allows for concise representation of what can be thousands of conformations. The hierarchy also recognizes and prunes incompatible conformations early in the calculation, eliminating redundant calculations of fit. We investigate the method by docking the MDL Drug Data Report (MDDR), an annotated database of 100,000 molecules, into apo and holo forms of seven unrelated targets. This annotated database allows us to track the ranking of tens to hundreds of annotated ligands in each of the docking systems. The binding sites and database are prepared in an automated fashion in an attempt to remove some human bias from the calculations. Many thousands of explicit and implicit ligand conformations may be docked in calculations not much longer than required for single conformer docking. As long as internal energies are not considered, recombination with the hierarchy is additive as the number of degrees of freedom is increased. Molecules with even millions of conformations can be docked in a few minutes on a single desktop computer. PMID:16101414

  9. A Hierarchical Modeling Framework for Multiple Observer Transect Surveys

    PubMed Central

    Conn, Paul B.; Laake, Jeffrey L.; Johnson, Devin S.

    2012-01-01

    Ecologists often use multiple observer transect surveys to census animal populations. In addition to animal counts, these surveys produce sequences of detections and non-detections for each observer. When combined with additional data (i.e. covariates such as distance from the transect line), these sequences provide the additional information to estimate absolute abundance when detectability on the transect line is less than one. Although existing analysis approaches for such data have proven extremely useful, they have some limitations. For instance, it is difficult to extrapolate from observed areas to unobserved areas unless a rigorous sampling design is adhered to; it is also difficult to share information across spatial and temporal domains or to accommodate habitat-abundance relationships. In this paper, we introduce a hierarchical modeling framework for multiple observer line transects that removes these limitations. In particular, abundance intensities can be modeled as a function of habitat covariates, making it easier to extrapolate to unsampled areas. Our approach relies on a complete data representation of the state space, where unobserved animals and their covariates are modeled using a reversible jump Markov chain Monte Carlo algorithm. Observer detections are modeled via a bivariate normal distribution on the probit scale, with dependence induced by a distance-dependent correlation parameter. We illustrate performance of our approach with simulated data and on a known population of golf tees. In both cases, we show that our hierarchical modeling approach yields accurate inference about abundance and related parameters. In addition, we obtain accurate inference about population-level covariates (e.g. group size). We recommend that ecologists consider using hierarchical models when analyzing multiple-observer transect data, especially when it is difficult to rigorously follow pre-specified sampling designs. We provide a new R package, hierarchical

  10. Planetary stability zones in hierarchical triple star systems

    NASA Astrophysics Data System (ADS)

    Verrier, P. E.; Evans, N. W.

    2007-12-01

    A symplectic integrator algorithm suitable for hierarchical triple systems is formulated and tested. The positions of the stars are followed in hierarchical Jacobi coordinates, whilst the planets are referenced purely to their primary. The algorithm is fast, accurate and easily generalized to incorporate collisions. There are five distinct cases - circumtriple orbits, circumbinary orbits and circumstellar orbits around each of the stars in the hierarchical triple - which require a different formulation of the symplectic integration algorithm. As an application, a survey of the stability zones for planets in hierarchical triples is presented, with the case of a single planet orbiting the inner binary considered in detail. Fits to the inner and the outer edges of the stability zone are computed. Considering the hierarchical triple as two decoupled binary systems, the earlier work of Holman and Wiegert on binaries is shown to be applicable to triples, except in the cases of high eccentricities and close or massive stars. Application to triple stars with good data in the multiple star catalogue suggests that more than 50 per cent are unable to support circumbinary planets, as the stable zone is non-existent or very narrow.

  11. Hierarchical graphs for rule-based modeling of biochemical systems

    PubMed Central

    2011-01-01

    Background In rule-based modeling, graphs are used to represent molecules: a colored vertex represents a component of a molecule, a vertex attribute represents the internal state of a component, and an edge represents a bond between components. Components of a molecule share the same color. Furthermore, graph-rewriting rules are used to represent molecular interactions. A rule that specifies addition (removal) of an edge represents a class of association (dissociation) reactions, and a rule that specifies a change of a vertex attribute represents a class of reactions that affect the internal state of a molecular component. A set of rules comprises an executable model that can be used to determine, through various means, the system-level dynamics of molecular interactions in a biochemical system. Results For purposes of model annotation, we propose the use of hierarchical graphs to represent structural relationships among components and subcomponents of molecules. We illustrate how hierarchical graphs can be used to naturally document the structural organization of the functional components and subcomponents of two proteins: the protein tyrosine kinase Lck and the T cell receptor (TCR) complex. We also show that computational methods developed for regular graphs can be applied to hierarchical graphs. In particular, we describe a generalization of Nauty, a graph isomorphism and canonical labeling algorithm. The generalized version of the Nauty procedure, which we call HNauty, can be used to assign canonical labels to hierarchical graphs or more generally to graphs with multiple edge types. The difference between the Nauty and HNauty procedures is minor, but for completeness, we provide an explanation of the entire HNauty algorithm. Conclusions Hierarchical graphs provide more intuitive formal representations of proteins and other structured molecules with multiple functional components than do the regular graphs of current languages for specifying rule-based models

  12. Fast pedestrian detection based on multiple instance hierarchical HOG matrices

    NASA Astrophysics Data System (ADS)

    Cheng, Guang; Meng, Long; Lin, Xinggang

    2013-12-01

    Many pedestrian detection research works focused on the improvement of detection performance, without considering the detection speed, making the detection algorithms not applicable for real-world requirement for real-time processing. To explore this problem, we first propose a pre-processing method Hierarchical HOG Matrices to replace the traditional integral histogram of gradients, which stores more data in the pre-processing phase to reduce computation time. A matrix-based detection computation structure is also proposed, which organize the massive data computations in the scanning detection process into matrix operations to optimize the overall speed. We then add multiple instance learning into the fast pedestrian detection algorithm to further enhance its accuracy. Experiments demonstrate that the proposed fast and robust pedestrian detection algorithm based on the multiple instance feature achieves an accuracy comparable to the latest algorithms, with the best speed among the algorithms with an accuracy of the same level.

  13. From binaries to multiples. II. Hierarchical multiplicity of F and G dwarfs

    SciTech Connect

    Tokovinin, Andrei

    2014-04-01

    Statistics of hierarchical multiplicity among solar-type dwarfs are studied using the distance-limited sample of 4847 targets presented in the accompanying Paper I. Known facts about binaries (multiplicity fraction 0.46, lognormal period distribution with median period 100 yr and logarithmic dispersion 2.4, and nearly uniform mass-ratio distribution independent of the period) are confirmed with a high statistical significance. The fraction of hierarchies with three or more components is 0.13 ± 0.01, and the fractions of targets with n = 1, 2, 3, ... components are 54:33:8:4:1. Subsystems in the secondary components are almost as frequent as in the primary components, but in half of such cases both inner pairs are present. The high frequency of those 2+2 hierarchies (4%) suggests that both inner pairs were formed by a common process. The statistics of hierarchies can be reproduced by simulations, assuming that the field is a mixture coming from binary-rich and binary-poor environments. Periods of the outer and inner binaries are selected recursively from the same lognormal distribution, subject to the stability constraint and accounting for the correlation between inner subsystems. The simulator can be used to evaluate the frequency of multiple systems with specified parameters. However, it does not reproduce the observed excess of inner periods shorter than 10 days, caused by tidal evolution.

  14. Clinical time series prediction: Toward a hierarchical dynamical system framework.

    PubMed

    Liu, Zitao; Hauskrecht, Milos

    2015-09-01

    Developing machine learning and data mining algorithms for building temporal models of clinical time series is important for understanding of the patient condition, the dynamics of a disease, effect of various patient management interventions and clinical decision making. In this work, we propose and develop a novel hierarchical framework for modeling clinical time series data of varied length and with irregularly sampled observations. Our hierarchical dynamical system framework for modeling clinical time series combines advantages of the two temporal modeling approaches: the linear dynamical system and the Gaussian process. We model the irregularly sampled clinical time series by using multiple Gaussian process sequences in the lower level of our hierarchical framework and capture the transitions between Gaussian processes by utilizing the linear dynamical system. The experiments are conducted on the complete blood count (CBC) panel data of 1000 post-surgical cardiac patients during their hospitalization. Our framework is evaluated and compared to multiple baseline approaches in terms of the mean absolute prediction error and the absolute percentage error. We tested our framework by first learning the time series model from data for the patients in the training set, and then using it to predict future time series values for the patients in the test set. We show that our model outperforms multiple existing models in terms of its predictive accuracy. Our method achieved a 3.13% average prediction accuracy improvement on ten CBC lab time series when it was compared against the best performing baseline. A 5.25% average accuracy improvement was observed when only short-term predictions were considered. A new hierarchical dynamical system framework that lets us model irregularly sampled time series data is a promising new direction for modeling clinical time series and for improving their predictive performance. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Clinical time series prediction: towards a hierarchical dynamical system framework

    PubMed Central

    Liu, Zitao; Hauskrecht, Milos

    2014-01-01

    Objective Developing machine learning and data mining algorithms for building temporal models of clinical time series is important for understanding of the patient condition, the dynamics of a disease, effect of various patient management interventions and clinical decision making. In this work, we propose and develop a novel hierarchical framework for modeling clinical time series data of varied length and with irregularly sampled observations. Materials and methods Our hierarchical dynamical system framework for modeling clinical time series combines advantages of the two temporal modeling approaches: the linear dynamical system and the Gaussian process. We model the irregularly sampled clinical time series by using multiple Gaussian process sequences in the lower level of our hierarchical framework and capture the transitions between Gaussian processes by utilizing the linear dynamical system. The experiments are conducted on the complete blood count (CBC) panel data of 1000 post-surgical cardiac patients during their hospitalization. Our framework is evaluated and compared to multiple baseline approaches in terms of the mean absolute prediction error and the absolute percentage error. Results We tested our framework by first learning the time series model from data for the patient in the training set, and then applying the model in order to predict future time series values on the patients in the test set. We show that our model outperforms multiple existing models in terms of its predictive accuracy. Our method achieved a 3.13% average prediction accuracy improvement on ten CBC lab time series when it was compared against the best performing baseline. A 5.25% average accuracy improvement was observed when only short-term predictions were considered. Conclusion A new hierarchical dynamical system framework that lets us model irregularly sampled time series data is a promising new direction for modeling clinical time series and for improving their predictive

  16. A self-defining hierarchical data system

    NASA Technical Reports Server (NTRS)

    Bailey, J.

    1992-01-01

    The Self-Defining Data System (SDS) is a system which allows the creation of self-defining hierarchical data structures in a form which allows the data to be moved between different machine architectures. Because the structures are self-defining they can be used for communication between independent modules in a distributed system. Unlike disk-based hierarchical data systems such as Starlink's HDS, SDS works entirely in memory and is very fast. Data structures are created and manipulated as internal dynamic structures in memory managed by SDS itself. A structure may then be exported into a caller supplied memory buffer in a defined external format. This structure can be written as a file or sent as a message to another machine. It remains static in structure until it is reimported into SDS. SDS is written in portable C and has been run on a number of different machine architectures. Structures are portable between machines with SDS looking after conversion of byte order, floating point format, and alignment. A Fortran callable version is also available for some machines.

  17. A new intelligent hierarchical fault diagnosis system

    SciTech Connect

    Huang, Y.C.; Huang, C.L.; Yang, H.T.

    1997-02-01

    As a part of a substation-level decision support system, a new intelligent Hierarchical Fault Diagnosis System for on-line fault diagnosis is presented in this paper. The proposed diagnosis system divides the fault diagnosis process into two phases. Using time-stamped information of relays and breakers, phase 1 identifies the possible fault sections through the Group Method of Data Handling (GMDH) networks, and phase 2 recognizes the types and detailed situations of the faults identified in phase 1 by using a fast bit-operation logical inference mechanism. The diagnosis system has been practically verified by testing on a typical Taiwan power secondary transmission system. Test results show that rapid and accurate diagnosis can be obtained with flexibility and portability for fault diagnosis purpose of diverse substations.

  18. HLA-DRB1 rheumatoid arthritis risk in African Americans at multiple levels: Hierarchical classification systems, amino acid positions and residues

    PubMed Central

    Reynolds, Richard J.; Ahmed, Altan F.; Danila, Maria I.; Hughes, Laura B.; Gregersen, Peter K.; Raychaudhuri, Soumya; Plenge, Robert M.; Bridges, S. Louis

    2014-01-01

    Objective To evaluate African American rheumatoid arthritis HLA-DRB1 genetic risk by three validated allele classification systems, and by amino acid position and residue. To compare the genetic risk between African American and European ancestries. Methods Four-digit HLA-DRB1 genotyping was performed on 561 autoantibody-positive African American cases and 776 African American controls. Association analysis was performed on Tezenas du Montcel (TdM); de Vries (DV); and Mattey classification system alleles and separately by amino acid position and individual residues. Results TdM S2 and S3P alleles were associated with RA (odds ratios (95% CI) 2.8 (2.0, 3.9) and 2.1 (1.7, 2.7), respectively). The DV (P-value=3.2 x 10−12) and Mattey (P-value=6.5 x 10−13) system alleles were both protective in African Americans. Amino acid position 11 (permutation P-value < 0.00001) accounted for nearly all variability explained by HLA-DRB1, although conditional analysis demonstrated that position 57 was also significant (0.01<= permutation P-val <=0.05). The valine and aspartic acid residues at position 11 conferred the highest risk for RA in African Americans. Conclusion With some exceptions, the genetic risk conferred by HLA-DRB1 in African Americans is similar to European ancestry at multiple levels: classification system (e.g., TdM), amino acid position (e.g. 11) and residue (Val 11). Unlike that reported from European ancestry, amino acid position 57 was associated with RA in African Americans, but positions 71 and 74 were not. Asp11 (OR = 1 in European ancestry) corresponds to the four digit classical allele, *09:01, also a risk allele for RA in Koreans. PMID:25524867

  19. HLA-DRB1-associated rheumatoid arthritis risk at multiple levels in African Americans: hierarchical classification systems, amino acid positions, and residues.

    PubMed

    Reynolds, Richard J; Ahmed, Altan F; Danila, Maria I; Hughes, Laura B; Gregersen, Peter K; Raychaudhuri, Soumya; Plenge, Robert M; Bridges, S Louis

    2014-12-01

    To evaluate HLA-DRB1 genetic risk of rheumatoid arthritis (RA) in African Americans by 3 validated allele classification systems and by amino acid position and residue, and to compare genetic risk between African American and European ancestries. Four-digit HLA-DRB1 genotyping was performed on 561 autoantibody-positive African American cases and 776 African American controls. Association analysis was performed on Tezenas du Montcel (TdM), de Vries (DV), and Mattey classification system alleles and separately by amino acid position and individual residues. TdM S2 and S3P alleles were associated with RA (odds ratio [95% confidence interval] 2.8 [2.0-3.9] and 2.1 [1.7-2.7], respectively). The DV (P = 3.2 × 10(-12)) and Mattey (P = 6.5 × 10(-13)) system alleles were both protective in African Americans. Amino acid position 11 (permutation P < 0.00001) accounted for nearly all variability explained by HLA-DRB1, although conditional analysis demonstrated that position 57 was also significant (0.01 ≤ permutation P ≤ 0.05). The valine and aspartic acid residues at position 11 conferred the highest risk of RA in African Americans. With some exceptions, the genetic risk conferred by HLA-DRB1 in African Americans is similar to that in individuals of European ancestry at multiple levels: classification system (e.g., TdM), amino acid position (e.g., 11), and residue (Val11). Unlike that reported for individuals of European ancestry, amino acid position 57 was associated with RA in African Americans, but positions 71 and 74 were not. Asp11 (odds ratio 1 in European ancestry) corresponds to the 4-digit classical allele *09:01, which is also a risk allele for RA in Koreans. Copyright © 2014 by the American College of Rheumatology.

  20. Modeling urban air pollution with optimized hierarchical fuzzy inference system.

    PubMed

    Tashayo, Behnam; Alimohammadi, Abbas

    2016-10-01

    Environmental exposure assessments (EEA) and epidemiological studies require urban air pollution models with appropriate spatial and temporal resolutions. Uncertain available data and inflexible models can limit air pollution modeling techniques, particularly in under developing countries. This paper develops a hierarchical fuzzy inference system (HFIS) to model air pollution under different land use, transportation, and meteorological conditions. To improve performance, the system treats the issue as a large-scale and high-dimensional problem and develops the proposed model using a three-step approach. In the first step, a geospatial information system (GIS) and probabilistic methods are used to preprocess the data. In the second step, a hierarchical structure is generated based on the problem. In the third step, the accuracy and complexity of the model are simultaneously optimized with a multiple objective particle swarm optimization (MOPSO) algorithm. We examine the capabilities of the proposed model for predicting daily and annual mean PM2.5 and NO2 and compare the accuracy of the results with representative models from existing literature. The benefits provided by the model features, including probabilistic preprocessing, multi-objective optimization, and hierarchical structure, are precisely evaluated by comparing five different consecutive models in terms of accuracy and complexity criteria. Fivefold cross validation is used to assess the performance of the generated models. The respective average RMSEs and coefficients of determination (R (2)) for the test datasets using proposed model are as follows: daily PM2.5 = (8.13, 0.78), annual mean PM2.5 = (4.96, 0.80), daily NO2 = (5.63, 0.79), and annual mean NO2 = (2.89, 0.83). The obtained results demonstrate that the developed hierarchical fuzzy inference system can be utilized for modeling air pollution in EEA and epidemiological studies.

  1. Secular Evolution of Hierarchical Triple Star Systems

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.; Kozinsky, Boris; Rasio, Frederic A.

    2000-05-01

    We derive octupole-level secular perturbation equations for hierarchical triple systems, using classical Hamiltonian perturbation techniques. Our equations describe the secular evolution of the orbital eccentricities and inclinations over timescales that are long compared to the orbital periods. By extending previous work done to leading (quadrupole) order to octupole level (i.e., including terms of order α3, where α≡a1/a2<1 is the ratio of semimajor axes), we obtain expressions that are applicable to a much wider range of parameters. In particular, our results can be applied to high-inclination as well as coplanar systems, and our expressions are valid for almost all mass ratios for which the system is in a stable hierarchical configuration. In contrast, the standard quadrupole-level theory of Kozai gives a vanishing result in the limit of zero relative inclination. The classical planetary perturbation theory, while valid to all orders in α, applies only to orbits of low-mass objects orbiting a common central mass, with low eccentricities and low relative inclinations. For triple systems containing a close inner binary, we also discuss the possible interaction between the classical Newtonian perturbations and the general relativistic precession of the inner orbit. In some cases we show that this interaction can lead to resonances and a significant increase in the maximum amplitude of eccentricity perturbations. We establish the validity of our analytic expressions by providing detailed comparisons with the results of direct numerical integrations of the three-body problem obtained for a large number of representative cases. In addition, we show that our expressions reduce correctly to previously published analytic results obtained in various limiting regimes. We also discuss applications of the theory in the context of several observed triple systems of current interest, including the millisecond pulsar PSR B1620-26 in M4, the giant planet in 16 Cygni, and

  2. Hierarchical structure of noncanonical Hamiltonian systems

    NASA Astrophysics Data System (ADS)

    Yoshida, Z.; Morrison, P. J.

    2016-02-01

    Topological constraints play a key role in the self-organizing processes that create structures in macro systems. In fact, if all possible degrees of freedom are actualized on equal footing without constraint, the state of ‘equipartition’ may bear no specific structure. Fluid turbulence is a typical example—while turbulent mixing seems to increase entropy, a variety of sustained vortical structures can emerge. In Hamiltonian formalism, some topological constraints are represented by Casimir invariants (for example, helicities of a fluid or a plasma), and then, the effective phase space is reduced to the Casimir leaves. However, a general constraint is not necessarily integrable, which precludes the existence of an appropriate Casimir invariant; the circulation is an example of such an invariant. In this work, we formulate a systematic method to embed a Hamiltonian system in an extended phase space; we introduce phantom fields and extend the Poisson algebra. A phantom field defines a new Casimir invariant, a cross helicity, which represents a topological constraint that is not integrable in the original phase space. Changing the perspective, a singularity of the extended system may be viewed as a subsystem on which the phantom fields (though they are actual fields, when viewed from the extended system) vanish, i.e., the original system. This hierarchical relation of degenerate Poisson manifolds enables us to see the ‘interior’ of a singularity as a sub Poisson manifold. The theory can be applied to describe bifurcations and instabilities in a wide class of general Hamiltonian systems (Yoshida and Morrison 2014 Fluid Dyn. Res. 46 031412).

  3. Hierarchical organization of macaque and cat cortical sensory systems explored with a novel network processor.

    PubMed Central

    Hilgetag, C C; O'Neill, M A; Young, M P

    2000-01-01

    subdivision of FST into two distinct areas, whose connectivity we predict, and the abolition of at least one of the less reliable rule constraints. Our analyses showed that the future collection of the same type of laminar constraints, or the inclusion of new hierarchical constraints from thalamocortical connections, will not resolve the problem of multiple optimal hierarchical representations for the primate visual system. Further data, however, may help to specify the relative ordering of some more areas. This indeterminacy of the visual hierarchy is in part due to the reported absence of some connections between cortical areas. These absences are consistent with limited cross-talk between differentiated processing streams in the system. Hence, hierarchical representation of the visual system is affected by, and must take into account, other organizational features, such as processing streams. PMID:10703045

  4. Multiple System Atrophy (MSA)

    MedlinePlus

    Multiple system atrophy (MSA) Overview By Mayo Clinic Staff Multiple system atrophy (MSA) is a rare, degenerative neurological disorder ... progresses gradually and eventually leads to death. Multiple system atrophy care at Mayo Clinic . Mayo Clinic Footer ...

  5. Bayesian Hierarchical Models to Augment the Mediterranean Forecast System

    DTIC Science & Technology

    2016-06-07

    Bayesian Hierarchical Models to Augment the Mediterranean Forecast System Ralph F. Milliff Colorado Research Associates Division NorthWest...last year. Our goal is to develop an ensemble ocean forecast methodology, using Bayesian Hierarchical Modelling (BHM) tools. The ocean ensemble...geostrophy model introduced by Royle et al. (1998). The second objective involves the accurate representation of forecast error covariance evolution in

  6. The multiple outliers detection using agglomerative hierarchical methods in circular regression model

    NASA Astrophysics Data System (ADS)

    Zanariah Satari, Siti; Di, Nur Faraidah Muhammad; Zakaria, Roslinazairimah

    2017-09-01

    Two agglomerative hierarchical clustering algorithms for identifying multiple outliers in circular regression model have been developed in this study. The agglomerative hierarchical clustering algorithm starts with every single data in a single cluster and it continues to merge with the closest pair of clusters according to some similarity criterion until all the data are grouped in one cluster. The single-linkage method is one of the simplest agglomerative hierarchical methods that is commonly used to detect outlier. In this study, we compared the performance of single-linkage method with another agglomerative hierarchical method, namely average linkage for detecting outlier in circular regression model. The performances of both methods were examined via simulation studies by measuring their “success” probability, masking effect, and swamping effect with different number of sample sizes and level of contaminations. The results show that the single-linkage method performs very well in detecting the multiple outliers with lower masking and swamping effects.

  7. Orbits of Subsystems in Four Hierarchical Multiple Stars

    NASA Astrophysics Data System (ADS)

    Tokovinin, Andrei

    2016-07-01

    Seven spectroscopic orbits in nearby solar-type multiple stars are presented. The primary of the chromospherically active star HIP 9642 is a 4.8 day double-lined pair; the outer 420 year visual orbit is updated, but remains poorly constrained. HIP 12780 is a quadruple system consisting of the resolved 6.7 year pair FIN 379 Aa,Ab, for which the combined orbit, masses, and orbital parallax are determined here, and the single-lined binary Ba,Bb with a period of 27.8 days. HIP 28790 is a young quintuple system composed of two close binaries, Aa,Ab and Ba,Bb, with periods of 221 and 13 days, respectively, and a single distant component C. Its subsystem Ba,Bb is peculiar, having a spectroscopic mass ratio of 0.89 but a magnitude difference of ˜2.2 mag. HIP 64478 also contains five stars: the A-component is a 29 year visual pair with a previously known 4 day twin subsystem, while the B-component is a contact binary with a period of 5.8 hr, seen nearly pole-on.

  8. Hierarchical robust nonlinear switching control design for propulsion systems

    NASA Astrophysics Data System (ADS)

    Leonessa, Alexander

    1999-09-01

    The desire for developing an integrated control system- design methodology for advanced propulsion systems has led to significant activity in modeling and control of flow compression systems in recent years. In this dissertation we develop a novel hierarchical switching control framework for addressing the compressor aerodynamic instabilities of rotating stall and surge. The proposed control framework accounts for the coupling between higher-order modes while explicitly addressing actuator rate saturation constraints and system modeling uncertainty. To develop a hierarchical nonlinear switching control framework, first we develop generalized Lyapunov and invariant set theorems for nonlinear dynamical systems wherein all regularity assumptions on the Lyapunov function and the system dynamics are removed. In particular, local and global stability theorems are given using lower semicontinuous Lyapunov functions. Furthermore, generalized invariant set theorems are derived wherein system trajectories converge to a union of largest invariant sets contained in intersections over finite intervals of the closure of generalized Lyapunov level surfaces. The proposed results provide transparent generalizations to standard Lyapunov and invariant set theorems. Using the generalized Lyapunov and invariant set theorems, a nonlinear control-system design framework predicated on a hierarchical switching controller architecture parameterized over a set of moving system equilibria is developed. Specifically, using equilibria- dependent Lyapunov functions, a hierarchical nonlinear control strategy is developed that stabilizes a given nonlinear system by stabilizing a collection of nonlinear controlled subsystems. The switching nonlinear controller architecture is designed based on a generalized lower semicontinuous Lyapunov function obtained by minimizing a potential function over a given switching set induced by the parameterized system equilibria. The proposed framework provides a

  9. A novel generic optimization method for irrigation scheduling under multiple objectives and multiple hierarchical layers in a canal network

    NASA Astrophysics Data System (ADS)

    Delgoda, Dilini; Malano, Hector; Saleem, Syed K.; Halgamuge, Malka N.

    2017-07-01

    This research proposes a novel generic method for irrigation scheduling in a canal network to optimize multiple objectives related to canal scheduling (e.g. maximizing water supply and minimizing imbalance of water distribution) within multiple hierarchical layers (e.g. the layers consisting of the main canal, distributaries) while utilizing traditional canal scheduling methods. It is based on modularizing the optimization process. The method is theoretically capable of optimizing an unlimited number of user-defined objectives within an unlimited number of hierarchical layers and only limited by resource availability (e.g. maximum canal capacity and water limitations) in the network. It allows flexible decision-making through quantification of the mutual effects of optimizing conflicting objectives and is adaptable to available multi-objective evolutionary algorithms. The method's application is demonstrated using a hypothetical canal network example with six objectives and three hierarchical layers, and a real scenario with four objectives and two layers.

  10. Multiple Object Retrieval in Image Databases Using Hierarchical Segmentation Tree

    ERIC Educational Resources Information Center

    Chen, Wei-Bang

    2012-01-01

    The purpose of this research is to develop a new visual information analysis, representation, and retrieval framework for automatic discovery of salient objects of user's interest in large-scale image databases. In particular, this dissertation describes a content-based image retrieval framework which supports multiple-object retrieval. The…

  11. Multiple Object Retrieval in Image Databases Using Hierarchical Segmentation Tree

    ERIC Educational Resources Information Center

    Chen, Wei-Bang

    2012-01-01

    The purpose of this research is to develop a new visual information analysis, representation, and retrieval framework for automatic discovery of salient objects of user's interest in large-scale image databases. In particular, this dissertation describes a content-based image retrieval framework which supports multiple-object retrieval. The…

  12. Hierarchical Discrete Event Supervisory Control of Aircraft Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Yasar, Murat; Tolani, Devendra; Ray, Asok; Shah, Neerav; Litt, Jonathan S.

    2004-01-01

    This paper presents a hierarchical application of Discrete Event Supervisory (DES) control theory for intelligent decision and control of a twin-engine aircraft propulsion system. A dual layer hierarchical DES controller is designed to supervise and coordinate the operation of two engines of the propulsion system. The two engines are individually controlled to achieve enhanced performance and reliability, necessary for fulfilling the mission objectives. Each engine is operated under a continuously varying control system that maintains the specified performance and a local discrete-event supervisor for condition monitoring and life extending control. A global upper level DES controller is designed for load balancing and overall health management of the propulsion system.

  13. Estimation of Reliability for Multiple-Component Measuring Instruments in Hierarchical Designs

    ERIC Educational Resources Information Center

    Raykov, Tenko; du Toit, Stephen H. C.

    2005-01-01

    A method for estimation of reliability for multiple-component measuring instruments with clustered data is outlined. The approach is applicable with hierarchical designs where individuals are nested within higher order units and exhibit possibly related performance on components of a scale of interest. The procedure is developed within the…

  14. Beyond the Basics: Preschool Children Label Objects Flexibly at Multiple Hierarchical Levels.

    ERIC Educational Resources Information Center

    Waxman, Sandra R.; Hatch, Thomas

    1992-01-01

    Examines (1) preschool children's production of multiple, hierarchically related labels; (2) the pragmatic consequences of the inherent asymmetry of inclusion relations; and (3) the influence of morphology (modifier plus noun constructions vs. simple lexemes) at the subordinate level. Performance shows an inability to label objects flexibly at…

  15. What Is Wrong with ANOVA and Multiple Regression? Analyzing Sentence Reading Times with Hierarchical Linear Models

    ERIC Educational Resources Information Center

    Richter, Tobias

    2006-01-01

    Most reading time studies using naturalistic texts yield data sets characterized by a multilevel structure: Sentences (sentence level) are nested within persons (person level). In contrast to analysis of variance and multiple regression techniques, hierarchical linear models take the multilevel structure of reading time data into account. They…

  16. Hierarchical Policy Model for Managing Heterogeneous Security Systems

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Young; Kim, Minsoo

    2007-12-01

    The integrated security management becomes increasingly complex as security manager must take heterogeneous security systems, different networking technologies, and distributed applications into consideration. The task of managing these security systems and applications depends on various systems and vender specific issues. In this paper, we present a hierarchical policy model which are derived from the conceptual policy, and specify means to enforce this behavior. The hierarchical policy model consist of five levels which are conceptual policy level, goal-oriented policy level, target policy level, process policy level and low-level policy.

  17. A Hierarchical Learning Control Framework for an Aerial Manipulation System

    NASA Astrophysics Data System (ADS)

    Ma, Le; Chi, yanxun; Li, Jiapeng; Li, Zhongsheng; Ding, Yalei; Liu, Lixing

    2017-07-01

    A hierarchical learning control framework for an aerial manipulation system is proposed. Firstly, the mechanical design of aerial manipulation system is introduced and analyzed, and the kinematics and the dynamics based on Newton-Euler equation are modeled. Secondly, the framework of hierarchical learning for this system is presented, in which flight platform and manipulator are controlled by different controller respectively. The RBF (Radial Basis Function) neural networks are employed to estimate parameters and control. The Simulation and experiment demonstrate that the methods proposed effective and advanced.

  18. A novel load balancing method for hierarchical federation simulation system

    NASA Astrophysics Data System (ADS)

    Bin, Xiao; Xiao, Tian-yuan

    2013-07-01

    In contrast with single HLA federation framework, hierarchical federation framework can improve the performance of large-scale simulation system in a certain degree by distributing load on several RTI. However, in hierarchical federation framework, RTI is still the center of message exchange of federation, and it is still the bottleneck of performance of federation, the data explosion in a large-scale HLA federation may cause overload on RTI, It may suffer HLA federation performance reduction or even fatal error. Towards this problem, this paper proposes a load balancing method for hierarchical federation simulation system based on queuing theory, which is comprised of three main module: queue length predicting, load controlling policy, and controller. The method promotes the usage of resources of federate nodes, and improves the performance of HLA simulation system with balancing load on RTIG and federates. Finally, the experiment results are presented to demonstrate the efficient control of the method.

  19. A Bayesian hierarchical surrogate outcome model for multiple sclerosis.

    PubMed

    Pozzi, Luca; Schmidli, Heinz; Ohlssen, David I

    2016-07-01

    The development of novel therapies in multiple sclerosis (MS) is one area where a range of surrogate outcomes are used in various stages of clinical research. While the aim of treatments in MS is to prevent disability, a clinical trial for evaluating a drugs effect on disability progression would require a large sample of patients with many years of follow-up. The early stage of MS is characterized by relapses. To reduce study size and duration, clinical relapses are accepted as primary endpoints in phase III trials. For phase II studies, the primary outcomes are typically lesion counts based on magnetic resonance imaging (MRI), as these are considerably more sensitive than clinical measures for detecting MS activity. Recently, Sormani and colleagues in 'Surrogate endpoints for EDSS worsening in multiple sclerosis' provided a systematic review and used weighted regression analyses to examine the role of either MRI lesions or relapses as trial level surrogate outcomes for disability. We build on this work by developing a Bayesian three-level model, accommodating the two surrogates and the disability endpoint, and properly taking into account that treatment effects are estimated with errors. Specifically, a combination of treatment effects based on MRI lesion count outcomes and clinical relapse was used to develop a study-level surrogate outcome model for the corresponding treatment effects based on disability progression. While the primary aim for developing this model was to support decision-making in drug development, the proposed model may also be considered for future validation. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Linking landscape characteristics to local grizzly bear abundance using multiple detection methods in a hierarchical model

    USGS Publications Warehouse

    Graves, T.A.; Kendall, K.C.; Royle, J. Andrew; Stetz, J.B.; Macleod, A.C.

    2011-01-01

    Few studies link habitat to grizzly bear Ursus arctos abundance and these have not accounted for the variation in detection or spatial autocorrelation. We collected and genotyped bear hair in and around Glacier National Park in northwestern Montana during the summer of 2000. We developed a hierarchical Markov chain Monte Carlo model that extends the existing occupancy and count models by accounting for (1) spatially explicit variables that we hypothesized might influence abundance; (2) separate sub-models of detection probability for two distinct sampling methods (hair traps and rub trees) targeting different segments of the population; (3) covariates to explain variation in each sub-model of detection; (4) a conditional autoregressive term to account for spatial autocorrelation; (5) weights to identify most important variables. Road density and per cent mesic habitat best explained variation in female grizzly bear abundance; spatial autocorrelation was not supported. More female bears were predicted in places with lower road density and with more mesic habitat. Detection rates of females increased with rub tree sampling effort. Road density best explained variation in male grizzly bear abundance and spatial autocorrelation was supported. More male bears were predicted in areas of low road density. Detection rates of males increased with rub tree and hair trap sampling effort and decreased over the sampling period. We provide a new method to (1) incorporate multiple detection methods into hierarchical models of abundance; (2) determine whether spatial autocorrelation should be included in final models. Our results suggest that the influence of landscape variables is consistent between habitat selection and abundance in this system. ?? 2011 The Authors. Animal Conservation ?? 2011 The Zoological Society of London.

  1. Control of discrete event systems modeled as hierarchical state machines

    NASA Technical Reports Server (NTRS)

    Brave, Y.; Heymann, M.

    1991-01-01

    The authors examine a class of discrete event systems (DESs) modeled as asynchronous hierarchical state machines (AHSMs). For this class of DESs, they provide an efficient method for testing reachability, which is an essential step in many control synthesis procedures. This method utilizes the asynchronous nature and hierarchical structure of AHSMs, thereby illustrating the advantage of the AHSM representation as compared with its equivalent (flat) state machine representation. An application of the method is presented where an online minimally restrictive solution is proposed for the problem of maintaining a controlled AHSM within prescribed legal bounds.

  2. Hierarchical multiple binary image encryption based on a chaos and phase retrieval algorithm in the Fresnel domain

    NASA Astrophysics Data System (ADS)

    Wang, Zhipeng; Lv, Xiaodong; Wang, Hongjuan; Hou, Chenxia; Gong, Qiong; Qin, Yi

    2016-03-01

    Based on the chaos and phase retrieval algorithm, a hierarchical multiple binary image encryption is proposed. In the encryption process, each plaintext is encrypted into a diffraction intensity pattern by two chaos-generated random phase masks (RPMs). Thereafter, the captured diffraction intensity patterns are partially selected by different binary masks and then combined together to form a single intensity pattern. The combined intensity pattern is saved as ciphertext. For decryption, an iterative phase retrieval algorithm is performed, in which a support constraint in the output plane and a median filtering operation are utilized to achieve a rapid convergence rate without a stagnation problem. The proposed scheme has a simple optical setup and large encryption capacity. In particular, it is well suited for constructing a hierarchical security system. The security and robustness of the proposal are also investigated.

  3. Hierarchical structure of biological systems: a bioengineering approach.

    PubMed

    Alcocer-Cuarón, Carlos; Rivera, Ana L; Castaño, Victor M

    2014-01-01

    A general theory of biological systems, based on few fundamental propositions, allows a generalization of both Wierner and Berthalanffy approaches to theoretical biology. Here, a biological system is defined as a set of self-organized, differentiated elements that interact pair-wise through various networks and media, isolated from other sets by boundaries. Their relation to other systems can be described as a closed loop in a steady-state, which leads to a hierarchical structure and functioning of the biological system. Our thermodynamical approach of hierarchical character can be applied to biological systems of varying sizes through some general principles, based on the exchange of energy information and/or mass from and within the systems.

  4. Hierarchical Search Strategy for Detecting Gravitational waves from Inspiraling Compact Binaries with Multiple Interferometers

    NASA Astrophysics Data System (ADS)

    Seader, Shawn; Bose, Sukanta

    2004-05-01

    Perhaps the most promising gravitational-wave source for detection with Earth-based interferometers is the compact binary system, such as a binary neutron star. For these sources, the inspiral waveform is well-known in the sensitive frequency band of the interferometers. This allows one to match-filter the output of the interferometer with many different templates of the pre-calculated waveforms. While operating, each interferometer takes strain data at a rate of several gigabytes per day. Matched filtering the outputs from multiple detectors, such as in a multi-detector coherent search, becomes very demanding computationally not only due to the enormous amount of data, but also due to the size of the parameter space that is accessible to a network of detectors. Indeed, the non-spinning binary waveform depends on a total of nine parameters, namely, the luminosity distance to the source, the time of arrival, the initial phase, the orbital inclination, the polarization angle, the two sky-position angles, and the two binary masses. Fortunately, it is possible to maximize a network's matched-filter output analytically over the first five parameters. Thus, a GW astronomer need search numerically only over a four-dimensional parameter space for a signal in the data. A "brute force" implementation of such a search is still not practicable. A promising strategy to make the search computationally viable is to perform it in multiple relatively inexpensive steps, i.e., implement it hierarchically. In a two-step hierarchical search, the data is filtered first with a bank of templates that are spaced coarsely on the parameter space. If any of these templates find a signal at or above a pre-set threshold on the signal-to-noise ratio (SNR), then that part of the data is filtered a second time with a more finely spaced bank of templates, centered around the filter that recorded the high SNR in the first, coarse bank. In this work we show how by setting the detection thresholds and

  5. An hierarchical approach to performance evaluation of expert systems

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Kavi, Srinu

    1985-01-01

    The number and size of expert systems is growing rapidly. Formal evaluation of these systems - which is not performed for many systems - increases the acceptability by the user community and hence their success. Hierarchical evaluation that had been conducted for computer systems is applied for expert system performance evaluation. Expert systems are also evaluated by treating them as software systems (or programs). This paper reports many of the basic concepts and ideas in the Performance Evaluation of Expert Systems Study being conducted at the University of Southwestern Louisiana.

  6. Latent Variable Regression 4-Level Hierarchical Model Using Multisite Multiple-Cohorts Longitudinal Data. CRESST Report 801

    ERIC Educational Resources Information Center

    Choi, Kilchan

    2011-01-01

    This report explores a new latent variable regression 4-level hierarchical model for monitoring school performance over time using multisite multiple-cohorts longitudinal data. This kind of data set has a 4-level hierarchical structure: time-series observation nested within students who are nested within different cohorts of students. These…

  7. Auditory deviance detection revisited: evidence for a hierarchical novelty system.

    PubMed

    Grimm, Sabine; Escera, Carles

    2012-07-01

    The fast detection of novel or deviant stimuli is a striking property of the auditory processing which reflects basic organizational principles of the auditory system and at the same time is of high practical significance. In human electrophysiology, deviance detection has been related to the occurrence of the mismatch negativity (MMN)--a component of the event-related potential (ERP) evoked 100 to 250 ms after the occurrence of a rare irregular sound. Recently, it has been shown in animal studies that a considerable portion of neurons in the auditory pathway exhibits a property called stimulus-specific adaptation enabling them to encode inter-sound relationships and to discharge at higher rates to rare changes in the acoustic stimulation. These neural responses have been linked to the deviant-evoked potential measured at the human scalp, but such responses occur at lower levels anatomically (e.g. the primary auditory cortex as well as the inferior colliculi) and are elicited earlier (20-30 ms after sound onset) in comparison to MMN. Further, they are not considerable enough in size to be interpreted as a direct neural correlate of the MMN. We review here a series of recent findings that provides a first step toward filling this gap between animal and human recordings by showing that comparably early modulations due to a sound's deviancy can be observed in humans, particularly in the middle-latency portion of the ERP within the first 50 ms after sound onset. The existence of those early indices of deviance detection preceding the well-studied MMN component strongly supports the idea that the encoding of regularities and the detection of violations is a basic principle of human auditory processing acting on multiple levels. This sustains the notion of a hierarchically organized novelty and deviance detection system in the human auditory system.

  8. Geometrical exponents of contour loops on synthetic multifractal rough surfaces: multiplicative hierarchical cascade p model.

    PubMed

    Hosseinabadi, S; Rajabpour, M A; Movahed, M Sadegh; Allaei, S M Vaez

    2012-03-01

    In this paper, we study many geometrical properties of contour loops to characterize the morphology of synthetic multifractal rough surfaces, which are generated by multiplicative hierarchical cascading processes. To this end, two different classes of multifractal rough surfaces are numerically simulated. As the first group, singular measure multifractal rough surfaces are generated by using the p model. The smoothened multifractal rough surface then is simulated by convolving the first group with a so-called Hurst exponent, H*. The generalized multifractal dimension of isoheight lines (contours), D(q), correlation exponent of contours, x(l), cumulative distributions of areas, ξ, and perimeters, η, are calculated for both synthetic multifractal rough surfaces. Our results show that for both mentioned classes, hyperscaling relations for contour loops are the same as that of monofractal systems. In contrast to singular measure multifractal rough surfaces, H* plays a leading role in smoothened multifractal rough surfaces. All computed geometrical exponents for the first class depend not only on its Hurst exponent but also on the set of p values. But in spite of multifractal nature of smoothened surfaces (second class), the corresponding geometrical exponents are controlled by H*, the same as what happens for monofractal rough surfaces.

  9. A hierarchical multiple-view approach to three-dimensional object recognition.

    PubMed

    Lin, W C; Liao, F Y; Tsao, C K; Lingutla, T

    1991-01-01

    A hierarchical approach is proposed for solving the surface and vertex correspondence problems in multiple-view-based 3D object-recognition systems. The proposed scheme is a coarse-to-fine search process, and a Hopfield network is used at each stage. Compared with conventional object-matching schemes, the proposed technique provides a more general and compact formulation of the problem and a solution more suitable for parallel implementation. At the coarse search stage, the surface matching scores between the input image and each object model in the database are computed through a Hopfield network and are used to select the candidates for further consideration. At the fine search stage, the object models selected from the previous stage are fed into another Hopfield network for vertex matching. The object model that has the best surface and vertex correspondences with the input image is finally singled out as the best matched model. Experimental results are reported using both synthetic and real range images to corroborate the proposed theory.

  10. Hierarchically Structured Recommender System for Improving NPS

    ERIC Educational Resources Information Center

    Kuang, Jieyan

    2016-01-01

    Net Promoter System (NPS) is well known as an evaluation measure of the growth engine of big companies in the business area. The ultimate goal of my research is to build an action rules and meta-actions based recommender system for improving NPS scores of 34 companies (clients) dealing with similar businesses in the US and Canada. With the given…

  11. Hierarchically Structured Recommender System for Improving NPS

    ERIC Educational Resources Information Center

    Kuang, Jieyan

    2016-01-01

    Net Promoter System (NPS) is well known as an evaluation measure of the growth engine of big companies in the business area. The ultimate goal of my research is to build an action rules and meta-actions based recommender system for improving NPS scores of 34 companies (clients) dealing with similar businesses in the US and Canada. With the given…

  12. P2MP MPLS-Based Hierarchical Service Management System

    NASA Astrophysics Data System (ADS)

    Kumaki, Kenji; Nakagawa, Ikuo; Nagami, Kenichi; Ogishi, Tomohiko; Ano, Shigehiro

    This paper proposes a point-to-multipoint (P2MP) Multi-Protocol Label Switching (MPLS) based hierarchical service management system. Traditionally, general management systems deployed in some service providers control MPLS Label Switched Paths (LSPs) (e.g., RSVP-TE and LDP) and services (e.g., L2VPN, L3VPN and IP) separately. In order for dedicated management systems for MPLS LSPs and services to cooperate with each other automatically, a hierarchical service management system has been proposed with the main focus on point-to-point (P2P) TE LSPs in MPLS path management. In the case where P2MP TE LSPs and services are deployed in MPLS networks, the dedicated management systems for P2MP TE LSPs and services must work together automatically. Therefore, this paper proposes a new algorithm that uses a correlation between P2MP TE LSPs and multicast VPN services based on a P2MP MPLS-based hierarchical service management architecture. Also, the capacity and performance of the proposed algorithm are evaluated by simulations, which are actually based on certain real MPLS production networks, and are compared to that of the algorithm for P2P TE LSPs. Results show this system is very scalable within real MPLS production networks. This system, with the automatic correlation, appears to be deployable in real MPLS production networks.

  13. Perception Strategies in Hierarchical Vision Systems

    DTIC Science & Technology

    2006-01-01

    example of a multi-layered neural network de- signed and trained via back-propagation to perform object detection and recognition tasks. It can be seen as a...difficult. In computational systems, feedback is often used in the training phase of neural networks and graphical models, however, the authors are unaware...algorithm, such as clus- tering or parametric models, as in [19, 17] or [31]. The convolutional network The system of LeCun et. al. [18] is an

  14. Heuristic decomposition for non-hierarchic systems

    NASA Technical Reports Server (NTRS)

    Bloebaum, Christina L.; Hajela, P.

    1991-01-01

    Design and optimization is substantially more complex in multidisciplinary and large-scale engineering applications due to the existing inherently coupled interactions. The paper introduces a quasi-procedural methodology for multidisciplinary optimization that is applicable for nonhierarchic systems. The necessary decision-making support for the design process is provided by means of an embedded expert systems capability. The method employs a decomposition approach whose modularity allows for implementation of specialized methods for analysis and optimization within disciplines.

  15. Proposal for hierarchical description of software systems

    NASA Technical Reports Server (NTRS)

    Thauboth, H.

    1973-01-01

    The programming of digital computers has developed into a new dimension full of diffculties, because the hardware of computers has become so powerful that more complex applications are entrusted to computers. The costs of software development, verification, and maintenance are outpacing those of the hardware and the trend is toward futher increase of sophistication of application of computers and consequently of sophistication of software. To obtain better visibility into software systems and to improve the structure of software systems for better tests, verification, and maintenance, a clear, but rigorous description and documentation of software is needed. The purpose of the report is to extend the present methods in order to obtain a documentation that better reflects the interplay between the various components and functions of a software system at different levels of detail without losing the precision in expression. This is done by the use of block diagrams, sequence diagrams, and cross-reference charts. In the appendices, examples from an actual large sofware system, i.e. the Marshall System for Aerospace Systems Simulation (MARSYAS), are presented. The proposed documentation structure is compatible to automation of updating significant portions of the documentation for better software change control.

  16. Exact dynamics of dissipative electronic systems and quantum transport: Hierarchical equations of motion approach

    NASA Astrophysics Data System (ADS)

    Jin, Jinshuang; Zheng, Xiao; Yan, Yijing

    2008-06-01

    A generalized quantum master equation theory that governs the exact, nonperturbative quantum dissipation and quantum transport is formulated in terms of hierarchically coupled equations of motion for an arbitrary electronic system in contact with electrodes under either a stationary or a nonstationary electrochemical potential bias. The theoretical construction starts with the influence functional in path integral, in which the electron creation and annihilation operators are Grassmann variables. Time derivatives on the influence functionals are then performed in a hierarchical manner. Both the multiple-frequency dispersion and the non-Markovian reservoir parametrization schemes are considered for the desired hierarchy construction. The resulting hierarchical equations of motion formalism is in principle exact and applicable to arbitrary electronic systems, including Coulomb interactions, under the influence of arbitrary time-dependent applied bias voltage and external fields. Both the conventional quantum master equation and the real-time diagrammatic formalism of Schön and co-workers can be readily obtained at well defined limits of the present theory. We also show that for a noninteracting electron system, the present hierarchical equations of motion formalism terminates at the second tier exactly, and the Landuer-Büttiker transport current expression is recovered. The present theory renders an exact and numerically tractable tool to evaluate various transient and stationary quantum transport properties of many-electron systems, together with the involving nonperturbative dissipative dynamics.

  17. Exact dynamics of dissipative electronic systems and quantum transport: Hierarchical equations of motion approach.

    PubMed

    Jin, Jinshuang; Zheng, Xiao; Yan, YiJing

    2008-06-21

    A generalized quantum master equation theory that governs the exact, nonperturbative quantum dissipation and quantum transport is formulated in terms of hierarchically coupled equations of motion for an arbitrary electronic system in contact with electrodes under either a stationary or a nonstationary electrochemical potential bias. The theoretical construction starts with the influence functional in path integral, in which the electron creation and annihilation operators are Grassmann variables. Time derivatives on the influence functionals are then performed in a hierarchical manner. Both the multiple-frequency dispersion and the non-Markovian reservoir parametrization schemes are considered for the desired hierarchy construction. The resulting hierarchical equations of motion formalism is in principle exact and applicable to arbitrary electronic systems, including Coulomb interactions, under the influence of arbitrary time-dependent applied bias voltage and external fields. Both the conventional quantum master equation and the real-time diagrammatic formalism of Schon and co-workers can be readily obtained at well defined limits of the present theory. We also show that for a noninteracting electron system, the present hierarchical equations of motion formalism terminates at the second tier exactly, and the Landuer-Buttiker transport current expression is recovered. The present theory renders an exact and numerically tractable tool to evaluate various transient and stationary quantum transport properties of many-electron systems, together with the involving nonperturbative dissipative dynamics.

  18. A Hierarchical Architecture for Computer Mail Systems,

    DTIC Science & Technology

    1981-05-01

    Block 20, if different from Report) IS. SUPPLEMENTARY NOTES 19. KEY WORDS (Continue on reverse side if necessary and Identify by block number) Electronic ... Mail Computer Message Systems Computer Mail 20. ABSTRACT (Continue on r’eree aide If neceelry and Idenity by block number) In this paper we present an

  19. Multiple System Atrophy (MSA)

    MedlinePlus

    ... to-day activities Vocal cord paralysis, which makes speech and breathing difficult Increased difficulty swallowing People typically live about seven to 10 years after multiple system atrophy symptoms first appear. However, the ...

  20. Hierarchical security system using real-valued data and orthogonal code in Fourier domain

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Jun; Seo, Dong-Hoan; Hwang, Kwang-Il; Lim, Tae-Woo

    2014-02-01

    We propose a novel hierarchical encryption scheme using orthogonal code in Fourier domain and decryption based on interferometer system. The proposed system is composed of hierarchical ciphertexts with positive real values which can be applied for practical transmission such as Internet, and decryption keys with real valued function which has orthogonal characteristic in the decryption system. Since the original information is encrypted on the Fourier plane, the proposed encryption is more tolerant to loss of key information by scratching or cutting than encryption in a spatial domain. The resulting image using Fourier transform and an interferometer system with constant phase retarder is then decrypted by use of a ciphertext with different security level and each of decryption keys made from the multiplication of orthogonal code and random phase code in order to enhance the level of security. We demonstrate the efficiency of the proposed method and the fault-tolerance properties of data loss through several simulations.

  1. Distribution system reliability assessment using hierarchical Markov modeling

    SciTech Connect

    Brown, R.E.; Gupta, S.; Christie, R.D.; Venkata, S.S.; Fletcher, R.

    1996-10-01

    Distribution system reliability assessment is concerned with power availability and power quality at each customer`s service entrance. This paper presents a new method, termed Hierarchical Markov Modeling (HMM), which can perform predictive distribution system reliability assessment. HMM is unique in that it decomposes the reliability model based on system topology, integrated protection systems, and individual protection devices. This structure, which easily accommodates the effects of backup protection, fault isolation, and load restoration, is compared to simpler reliability models. HMM is then used to assess the reliability of an existing utility distribution system and to explore the reliability impact of several design improvement options.

  2. The hierarchical triple system DY Lyncis

    NASA Astrophysics Data System (ADS)

    Dimitrov, W.; Lehmann, H.; Kamiński, K.; Kamińska, M. K.; Zgórz, M.; Gibowski, M.

    2017-04-01

    We present the results of a six-year spectroscopic monitoring of DY Lyncis. Three different echelle spectrographs were used to collect the spectroscopic data. Each DY Lyncis spectrum contains lines of three different stars. Two of them belong to a very close eclipsing binary (EB) with an orbital period of 1.3 d. The reflex motion due to the third body can be observed in the radial velocities of the EB. We found the period of the wide orbit to be 281 d and its eccentricity is 0.33. We used the Wilson-Devinney method to fit both orbits. The analysis revealed that the EB consists of two very similar stars of 1.21 and 1.14 M⊙, corresponding to a mass ratio of 0.94. The fit of the long-period orbit showed that the third body is the most massive component in the system, its mass is 1.40 M⊙. Additionally, the atmospheric parameters were calculated for all three components. For that, we acquired spectra with a 2-m class telescope where we obtained sufficient signal-to-noise ratio. We derived temperatures of 6370 ± 150 and 6260 ± 140 K for the EB components, and 6380 ± 110 K for the most massive star. From the combined photometric and spectroscopic analysis, we estimate that the distance and age of the system are 285 pc and 2.5 Gyr, respectively.

  3. Implementation of system intelligence in a 3-tier telemedicine/PACS hierarchical storage management system

    NASA Astrophysics Data System (ADS)

    Chao, Woodrew; Ho, Bruce K. T.; Chao, John T.; Sadri, Reza M.; Huang, Lu J.; Taira, Ricky K.

    1995-05-01

    Our tele-medicine/PACS archive system is based on a three-tier distributed hierarchical architecture, including magnetic disk farms, optical jukebox, and tape jukebox sub-systems. The hierarchical storage management (HSM) architecture, built around a low cost high performance platform [personal computers (PC) and Microsoft Windows NT], presents a very scaleable and distributed solution ideal for meeting the needs of client/server environments such as tele-medicine, tele-radiology, and PACS. These image based systems typically require storage capacities mirroring those of film based technology (multi-terabyte with 10+ years storage) and patient data retrieval times at near on-line performance as demanded by radiologists. With the scaleable architecture, storage requirements can be easily configured to meet the needs of the small clinic (multi-gigabyte) to those of a major hospital (multi-terabyte). The patient data retrieval performance requirement was achieved by employing system intelligence to manage migration and caching of archived data. Relevant information from HIS/RIS triggers prefetching of data whenever possible based on simple rules. System intelligence embedded in the migration manger allows the clustering of patient data onto a single tape during data migration from optical to tape medium. Clustering of patient data on the same tape eliminates multiple tape loading and associated seek time during patient data retrieval. Optimal tape performance can then be achieved by utilizing the tape drives high performance data streaming capabilities thereby reducing typical data retrieval delays associated with streaming tape devices.

  4. RedeR: R/Bioconductor package for representing modular structures, nested networks and multiple levels of hierarchical associations

    PubMed Central

    2012-01-01

    Visualization and analysis of molecular networks are both central to systems biology. However, there still exists a large technological gap between them, especially when assessing multiple network levels or hierarchies. Here we present RedeR, an R/Bioconductor package combined with a Java core engine for representing modular networks. The functionality of RedeR is demonstrated in two different scenarios: hierarchical and modular organization in gene co-expression networks and nested structures in time-course gene expression subnetworks. Our results demonstrate RedeR as a new framework to deal with the multiple network levels that are inherent to complex biological systems. RedeR is available from http://bioconductor.org/packages/release/bioc/html/RedeR.html. PMID:22531049

  5. A Petri net controller for distributed hierarchical systems. Thesis

    NASA Technical Reports Server (NTRS)

    Peck, Joseph E.

    1991-01-01

    The solutions to a wide variety of problems are often best organized as a distributed hierarchical system. These systems can be graphically and mathematically modeled through the use of Petri nets, which can easily represent synchronous, asynchronous, and concurrent operations. This thesis presents a controller implementation based on Petri nets and a design methodology for the interconnection of distributed Petri nets. Two case studies are presented in which the controller operates a physical system, the Center for Intelligent Robotic Systems for Space Exploration Dual Arm Robotic Testbed.

  6. Compiler-Directed File Layout Optimization for Hierarchical Storage Systems

    DOE PAGES

    Ding, Wei; Zhang, Yuanrui; Kandemir, Mahmut; ...

    2013-01-01

    File layout of array data is a critical factor that effects the behavior of storage caches, and has so far taken not much attention in the context of hierarchical storage systems. The main contribution of this paper is a compiler-driven file layout optimization scheme for hierarchical storage caches. This approach, fully automated within an optimizing compiler, analyzes a multi-threaded application code and determines a file layout for each disk-resident array referenced by the code, such that the performance of the target storage cache hierarchy is maximized. We tested our approach using 16 I/O intensive application programs and compared its performancemore » against two previously proposed approaches under different cache space management schemes. Our experimental results show that the proposed approach improves the execution time of these parallel applications by 23.7% on average.« less

  7. Hierarchical fuzzy control of low-energy building systems

    SciTech Connect

    Yu, Zhen; Dexter, Arthur

    2010-04-15

    A hierarchical fuzzy supervisory controller is described that is capable of optimizing the operation of a low-energy building, which uses solar energy to heat and cool its interior spaces. The highest level fuzzy rules choose the most appropriate set of lower level rules according to the weather and occupancy information; the second level fuzzy rules determine an optimal energy profile and the overall modes of operation of the heating, ventilating and air-conditioning system (HVAC); the third level fuzzy rules select the mode of operation of specific equipment, and assign schedules to the local controllers so that the optimal energy profile can be achieved in the most efficient way. Computer simulation is used to compare the hierarchical fuzzy control scheme with a supervisory control scheme based on expert rules. The performance is evaluated by comparing the energy consumption and thermal comfort. (author)

  8. Reimplementing the Hierarchical Data System using HDF5

    NASA Astrophysics Data System (ADS)

    Jenness, Tim

    2015-09-01

    The Starlink Hierarchical Data System has been a very successful niche astronomy file format and library for over 30 years. Development of the library was frozen ten years ago when funding for Starlink was stopped and almost no-one remains who understands the implementation details. To ensure the long-term sustainability of the Starlink application software and to make the extensible N-Dimensional Data Format accessible to a broader range of users, we propose to re-implement the HDS library application interface as a layer on top of the Hierarchical Data Format version 5. We present an overview of the new implementation of version 5 of the HDS file format and describe differences between the expectations of the HDS and HDF5 library interfaces. We finish by comparing the old and new HDS implementations by looking at a comparison of file sizes and by comparing performance benchmarks.

  9. Hierarchical multiple informants models: examining food environment contributions to the childhood obesity epidemic.

    PubMed

    Baek, Jonggyu; Sánchez, Brisa N; Sanchez-Vaznaugh, Emma V

    2014-02-20

    Methods for multiple informants help to estimate the marginal effect of each multiple source predictor and formally compare the strength of their association with an outcome. We extend multiple informant methods to the case of hierarchical data structures to account for within cluster correlation. We apply the proposed method to examine the relationship between features of the food environment near schools and children's body mass index z-scores (BMIz). Specifically, we compare the associations between two different features of the food environment (fast food restaurants and convenience stores) with BMIz and investigate how the association between the number of fast food restaurants or convenience stores and child's BMIz varies across distance from a school. The newly developed methodology enhances the types of research questions that can be asked by investigators studying effects of environment on childhood obesity and can be applied to other fields.

  10. Recent results on the hierarchical triple system HD 150136

    NASA Astrophysics Data System (ADS)

    Gosset, E.; Berger, J. P.; Absil, O.; Le Bouquin, J. B.; Sana, H.; Mahy, L.; De Becker, M.

    2013-06-01

    HD 150136 is a hierarchical triple system, non-thermal radio emitter, made of three O stars totalling some 130 solar masses. The 2.67-day inner orbit is rather well-known. Recent works derived a good approximation for the outer orbit with a period of 3000 days. We report here on interferometric observations that allow us to angularly resolve the outer orbit. First evidences for an astrometric displacement are given. The determination of the outer system orbit gives access to the inclinations of the systems and to the masses, including the one of the O3-O3.5 primary star.

  11. Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials.

    PubMed

    Brough, David B; Wheeler, Daniel; Kalidindi, Surya R

    2017-03-01

    There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers.

  12. A Multi-layer, Hierarchical Information Management System for the Smart Grid

    SciTech Connect

    Lu, Ning; Du, Pengwei; Paulson, Patrick R.; Greitzer, Frank L.; Guo, Xinxin; Hadley, Mark D.

    2011-10-10

    This paper presents the modeling approach, methodologies, and initial results of setting up a multi-layer, hierarchical information management system (IMS) for the smart grid. The IMS allows its users to analyze the data collected by multiple control and communication networks to characterize the states of the smart grid. Abnormal, corrupted, or erroneous measurement data and outliers are detected and analyzed to identify whether they are caused by random equipment failures, unintentional human errors, or deliberate tempering attempts. Data collected from different information networks are crosschecked for data integrity based on redundancy, dependency, correlation, or cross-correlations, which reveal the interdependency between data sets. A hierarchically structured reasoning mechanism is used to rank possible causes of an event to aid the system operators to proactively respond or provide mitigation recommendations to remove or neutralize the threats. The model provides satisfactory performance on identifying the cause of an event and significantly reduces the need of processing myriads of data collected.

  13. Discrete synchronization of massively connected systems using hierarchical couplings

    NASA Astrophysics Data System (ADS)

    Poignard, Camille

    2016-04-01

    We study the synchronization of massively connected dynamical systems for which the interactions come from the succession of couplings forming a global hierarchical coupling process. Motivations of this work come from the growing necessity of understanding properties of complex systems that often exhibit a hierarchical structure. Starting with a set of 2n systems, the couplings we consider represent a two-by-two matching process that gather them in larger and larger groups of systems, providing to the whole set a structure in n stages, corresponding to n scales of hierarchy. This leads us naturally to the synchronization of a Cantor set of systems, indexed by { 0 , 1 } N, using the closed-open sets defined by n-tuples of 0 and 1 that permit us to make the link with the finite previous situation of 2n systems: we obtain a global synchronization result generalizing this case. In the same context, we deal with this question when some defects appear in the hierarchy, that is to say when some couplings among certain systems do not happen at a given stage of the hierarchy. We prove we can accept an infinite number of broken links inside the hierarchy while keeping a local synchronization, under the condition that these defects are present at the N smallest scales of the hierarchy (for a fixed integer N) and they be enough spaced out in those scales.

  14. Orbital Stability of the Hierarchical Triple System HIP 3678

    NASA Astrophysics Data System (ADS)

    Kirschbaum, Asher; Nordhaus, Jason

    2017-01-01

    HIP 3678 is a hierarchical triple system located in the center of planetary nebula (PN) NGC 246. The central star of the PN is a 0.84 M_sun PG 1159 star with a near-equal-mass K-dwarf companion and a recently discovered 0.1 M_sun tertiary companion at a projected separation of 500 AU. Using the highly-accurate, non-symplectic IAS15 integrator in REBOUND, we investigate the long-term stability of the system for scenarios consistent with current observational constraints on the orbital parameters.

  15. A Hierarchical Security Architecture for Cyber-Physical Systems

    SciTech Connect

    Quanyan Zhu; Tamer Basar

    2011-08-01

    Security of control systems is becoming a pivotal concern in critical national infrastructures such as the power grid and nuclear plants. In this paper, we adopt a hierarchical viewpoint to these security issues, addressing security concerns at each level and emphasizing a holistic cross-layer philosophy for developing security solutions. We propose a bottom-up framework that establishes a model from the physical and control levels to the supervisory level, incorporating concerns from network and communication levels. We show that the game-theoretical approach can yield cross-layer security strategy solutions to the cyber-physical systems.

  16. Scale invariance and invariant scaling in a mixed hierarchical system.

    PubMed

    Shnirman, M G; Blanter, E M

    1999-11-01

    We consider a mixed hierarchical model with heterogeneous and monotone conditions of destruction. We investigate how scaling properties of defects in the model are related with heterogeneity of rules of destruction, determined by concentration of the mixture. The system demonstrates different kinds of criticality as a general form of system behavior. The following forms of critical behavior are obtained: stability, catastrophe, scale invariance, and invariant scaling. Different slopes of the magnitude-frequency relation are realized in areas of critical stability and catastrophe. A simple relation between the slope of magnitude-frequency relation and parameters of the mixture is established.

  17. Optimal design of an irregular Fresnel lens for multiple light sources using a three-layered Hierarchical Genetic Algorithm.

    PubMed

    Chen, Wen-Gong; Uang, Chii-Maw; Jou, Chen-Hai

    2007-08-06

    A two-layered Hierarchical Genetic Algorithm (HGA) was proposed in a previous paper to solve the design problem of a large scale Fresnel lens used in a multiple-source lighting system. The research objective of this paper is to extend the previous work by utilizing a three-layered HGA. The goal of the suggested approach is to decrease the reliance on deciding the number of groove segments for the designed Fresnel lenses, as well as to increase the variety of groove angles in a segment to improve the performance of the designed Fresnel lens. The proposed algorithm will be applied on a simulated reading light system, and the simulation results demonstrate that the proposed approach not only makes the design of a large scale Fresnel lens more feasible but also works better than the previous one in both illuminance and uniformity for a simulated reading light system.

  18. Planning In A Hierarchical Nested Autonomous Control System

    NASA Astrophysics Data System (ADS)

    Meystel, A.

    1987-02-01

    In this paper, theoretical foundations of planning processes are outlined in a form applicable for design and control of autonomous mobile robots. Planning/control is shown to be a unified recursive operation of decision making applied to a nested hierarchy of knowledge representation. The core of the theory is based upon methods developed in the areas of Post-production systems, theory of coding, and the team theory of decentralized stochastic control. A class of autonomous control systems for robots is defined, and a problem of information representation is addressed for this class. A phenomenon of nesting is analyzed and the minimum c-entropy rule is determined for arranging efficient design and control procedures for systems of intelligent control. A concept of nested hierarchical knowledge-based controller is employed in this paper which enables minimum-time control using nested dynamic programming. An application of this concept is unfolded for a system of knowledge-based control of an autonomous mobile robot. Key words: Autonomous Control Systems, Decision Making, Production Systems, Decentralized Stochastic Control, Dynamic Programming, Hierarchical Control, Knowledge Based Controllers, E-entropy, Planning, Navigation, Guidance, Prediction, Contingencies, Mobile Robots.

  19. Recognition of hierarchically encoded images by technical and biological systems.

    PubMed

    Hartmann, G

    1987-01-01

    All the contours and regions of objects can be mapped to code-trees of the Hierarchical Structure Code (HSC). Invariant features like structure classes, shape descriptions, or relations between structures and components may be easily extracted from the HSC. HSC-based pattern recognition provides a straightforward transition between the signal-space of the image and the space of its symbolic representation. Physiological data are well predicted and do not exclude an implementation of an HSC-based system within the visual cortex.

  20. Modelling habitat associations with fingernail clam (Family: Sphaeriidae) counts at multiple spatial scales using hierarchical count models

    USGS Publications Warehouse

    Gray, B.R.; Haro, R.J.; Rogala, J.T.; Sauer, J.S.

    2005-01-01

    1. Macroinvertebrate count data often exhibit nested or hierarchical structure. Examples include multiple measurements along each of a set of streams, and multiple synoptic measurements from each of a set of ponds. With data exhibiting hierarchical structure, outcomes at both sampling (e.g. Within stream) and aggregated (e.g. Stream) scales are often of interest. Unfortunately, methods for modelling hierarchical count data have received little attention in the ecological literature. 2. We demonstrate the use of hierarchical count models using fingernail clam (Family: Sphaeriidae) count data and habitat predictors derived from sampling and aggregated spatial scales. The sampling scale corresponded to that of a standard Ponar grab (0.052 m(2)) and the aggregated scale to impounded and backwater regions within 38-197 km reaches of the Upper Mississippi River. Impounded and backwater regions were resampled annually for 10 years. Consequently, measurements on clams were nested within years. Counts were treated as negative binomial random variates, and means from each resampling event as random departures from the impounded and backwater region grand means. 3. Clam models were improved by the addition of covariates that varied at both the sampling and regional scales. Substrate composition varied at the sampling scale and was associated with model improvements, and reductions (for a given mean) in variance at the sampling scale. Inorganic suspended solids (ISS) levels, measured in the summer preceding sampling, also yielded model improvements and were associated with reductions in variances at the regional rather than sampling scales. ISS levels were negatively associated with mean clam counts. 4. Hierarchical models allow hierarchically structured data to be modelled without ignoring information specific to levels of the hierarchy. In addition, information at each hierarchical level may be modelled as functions of covariates that themselves vary by and within levels. As

  1. Hierarchical pictorial structures for simultaneously localizing multiple organs in volumetric pre-scan CT

    NASA Astrophysics Data System (ADS)

    Montillo, Albert; Song, Qi; Das, Bipul; Yin, Zhye

    2015-03-01

    Parsing volumetric computed tomography (CT) into 10 or more salient organs simultaneously is a challenging task with many applications such as personalized scan planning and dose reporting. In the clinic, pre-scan data can come in the form of very low dose volumes acquired just prior to the primary scan or from an existing primary scan. To localize organs in such diverse data, we propose a new learning based framework that we call hierarchical pictorial structures (HPS) which builds multiple levels of models in a tree-like hierarchy that mirrors the natural decomposition of human anatomy from gross structures to finer structures. Each node of our hierarchical model learns (1) the local appearance and shape of structures, and (2) a generative global model that learns probabilistic, structural arrangement. Our main contribution is twofold. First we embed the pictorial structures approach in a hierarchical framework which reduces test time image interpretation and allows for the incorporation of additional geometric constraints that robustly guide model fitting in the presence of noise. Second we guide our HPS framework with the probabilistic cost maps extracted using random decision forests using volumetric 3D HOG features which makes our model fast to train and fast to apply to novel test data and posses a high degree of invariance to shape distortion and imaging artifacts. All steps require approximate 3 mins to compute and all organs are located with suitably high accuracy for our clinical applications such as personalized scan planning for radiation dose reduction. We assess our method using a database of volumetric CT scans from 81 subjects with widely varying age and pathology and with simulated ultra-low dose cadaver pre-scan data.

  2. Hierarchical Multiple Regression Modelling on Predictors of Behavior and Sexual Practices at Takoradi Polytechnic, Ghana

    PubMed Central

    Turkson, Anthony Joe; Otchey, James Eric

    2015-01-01

    Introduction: Various psychosocial studies on health related lifestyles lay emphasis on the fact that the perception one has of himself as being at risk of HIV/AIDS infection was a necessary condition for preventive behaviors to be adopted. Hierarchical Multiple Regression models was used to examine the relationship between eight independent variables and one dependent variable to isolate predictors which have significant influence on behavior and sexual practices. Methods: A Cross-sectional design was used for the study. Structured close-ended interviewer-administered questionnaire was used to collect primary data. Multistage stratified technique was used to sample views from 380 students from Takoradi Polytechnic, Ghana. A Hierarchical multiple regression model was used to ascertain the significance of certain predictors of sexual behavior and practices. Results: The variables that were extracted from the multiple regression were; for the constant; β=14.202, t=2.279, p=0.023, variable is significant; for the marital status; β=0.092, t=1.996, p<0.05, variable is significant; for the knowledge on AIDs; β= 0.090, t=1.996, p<0.05, variable is significant; for the attitude towards HIV/AIDs; β=0.486, t=10.575, p<0.001, variable is highly significant. Thus, the best fitting model for predicting behavior and sexual practices was a linear combination of the constant, one’s marital status, knowledge on HIV/AIDs and Attitude towards HIV/AIDs., Y (Behavior and sexual practices) = β0 + β1 (Marital status) + β2 (Knowledge on HIV AIDs issues) + β3 (Attitude towards HIV AIDs issues) β0, β1, β2 and β3 are respectively 14.201, 2.038, 0.148 and 0.486; the higher the better. Conclusions: Attitude and behavior change education on HIV/AIDs should be intensified in the institution so that students could adopt better lifestyles. PMID:25946917

  3. Hierarchical multiple regression modelling on predictors of behavior and sexual practices at Takoradi Polytechnic, Ghana.

    PubMed

    Turkson, Anthony Joe; Otchey, James Eric

    2015-01-14

    Various psychosocial studies on health related lifestyles lay emphasis on the fact that the perception one has of himself as being at risk of HIV/AIDS infection was a necessary condition for preventive behaviors to be adopted. Hierarchical Multiple Regression models was used to examine the relationship between eight independent variables and one dependent variable to isolate predictors which have significant influence on behavior and sexual practices. A Cross-sectional design was used for the study. Structured close-ended interviewer-administered questionnaire was used to collect primary data. Multistage stratified technique was used to sample views from 380 students from Takoradi Polytechnic, Ghana. A Hierarchical multiple regression model was used to ascertain the significance of certain predictors of sexual behavior and practices. The variables that were extracted from the multiple regression were; for the constant; Beta=14.202, t=2.279, p=0.023, variable is significant; for the marital status; Beta=0.092, t=1.996, p<0.05, variable is significant; for the knowledge on AIDs; Beta=0.090, t=1.996, p<0.05, variable is significant; for the attitude towards HIV/AIDs; =0.486, t=10.575, p<0.001, variable is highly significant. Thus, the best fitting model for predicting behavior and sexual practices was a linear combination of the constant, one's marital status, knowledge on HIV/AIDs and Attitude towards HIV/AIDs., Y(Behavior and sexual practies)= Beta0+Beta1(Marital status)+Beta2(Knowledge on HIV/AIDs issues)+Beta3(Attitude towards HIV/AIDs issues) Beta0, Beta1, Beta2 and Beta3 are respectively 14.201, 2.038, 0.148 and 0.486; the higher the better. Attitude and behavior change education on HIV/AIDs should be intensified in the institution so that students could adopt better lifestyles.

  4. DISTURBANCE PATTERNS IN A SOCIO-ECOLOGICAL SYSTEM AT MULTIPLE SCALES

    EPA Science Inventory

    Ecological systems with hierarchical organization and non-equilibrium dynamics require multiple-scale analyses to comprehend how a system is structured and to formulate hypotheses about regulatory mechanisms. Characteristic scales in real landscapes are determined by, or at least...

  5. DISTURBANCE PATTERNS IN A SOCIO-ECOLOGICAL SYSTEM AT MULTIPLE SCALES

    EPA Science Inventory

    Ecological systems with hierarchical organization and non-equilibrium dynamics require multiple-scale analyses to comprehend how a system is structured and to formulate hypotheses about regulatory mechanisms. Characteristic scales in real landscapes are determined by, or at least...

  6. Hierarchical Modeling and Robust Synthesis for the Preliminary Design of Large Scale Complex Systems

    NASA Technical Reports Server (NTRS)

    Koch, Patrick N.

    1997-01-01

    Large-scale complex systems are characterized by multiple interacting subsystems and the analysis of multiple disciplines. The design and development of such systems inevitably requires the resolution of multiple conflicting objectives. The size of complex systems, however, prohibits the development of comprehensive system models, and thus these systems must be partitioned into their constituent parts. Because simultaneous solution of individual subsystem models is often not manageable iteration is inevitable and often excessive. In this dissertation these issues are addressed through the development of a method for hierarchical robust preliminary design exploration to facilitate concurrent system and subsystem design exploration, for the concurrent generation of robust system and subsystem specifications for the preliminary design of multi-level, multi-objective, large-scale complex systems. This method is developed through the integration and expansion of current design techniques: Hierarchical partitioning and modeling techniques for partitioning large-scale complex systems into more tractable parts, and allowing integration of subproblems for system synthesis; Statistical experimentation and approximation techniques for increasing both the efficiency and the comprehensiveness of preliminary design exploration; and Noise modeling techniques for implementing robust preliminary design when approximate models are employed. Hierarchical partitioning and modeling techniques including intermediate responses, linking variables, and compatibility constraints are incorporated within a hierarchical compromise decision support problem formulation for synthesizing subproblem solutions for a partitioned system. Experimentation and approximation techniques are employed for concurrent investigations and modeling of partitioned subproblems. A modified composite experiment is introduced for fitting better predictive models across the ranges of the factors, and an approach for

  7. Accelerated multiplicative updates and hierarchical ALS algorithms for nonnegative matrix factorization.

    PubMed

    Gillis, Nicolas; Glineur, François

    2012-04-01

    Nonnegative matrix factorization (NMF) is a data analysis technique used in a great variety of applications such as text mining, image processing, hyperspectral data analysis, computational biology, and clustering. In this letter, we consider two well-known algorithms designed to solve NMF problems: the multiplicative updates of Lee and Seung and the hierarchical alternating least squares of Cichocki et al. We propose a simple way to significantly accelerate these schemes, based on a careful analysis of the computational cost needed at each iteration, while preserving their convergence properties. This acceleration technique can also be applied to other algorithms, which we illustrate on the projected gradient method of Lin. The efficiency of the accelerated algorithms is empirically demonstrated on image and text data sets and compares favorably with a state-of-the-art alternating nonnegative least squares algorithm.

  8. Coalescence-Induced Jumping of Multiple Condensate Droplets on Hierarchical Superhydrophobic Surfaces

    PubMed Central

    Chen, Xuemei; Patel, Ravi S.; Weibel, Justin A.; Garimella, Suresh V.

    2016-01-01

    Coalescence-induced jumping of condensate droplets from a superhydrophobic surface with hierarchical micro/nanoscale roughness is quantitatively characterized. Experimental observations show that the condensate droplet jumping is induced by coalescence of multiple droplets of different sizes, and that the coalesced droplet trajectories typically deviate from the surface normal. A depth-from-defocus image processing technique is developed to track the out-of-plane displacement of the jumping droplets, so as to accurately measure the droplet size and velocity. The results demonstrate that the highest jumping velocity is achieved when two droplets coalesce. The jumping velocity decreases gradually with an increase in the number of coalescing droplets, despite the greater potential surface energy released upon coalescence. A general theoretical model that accounts for viscous dissipation, surface adhesion, line tension, the initial droplet wetting states, and the number and sizes of the coalescing droplets is developed to explain the trends of droplet jumping velocity observed in the experiments. PMID:26725512

  9. The evolution of hierarchical triple star-systems

    NASA Astrophysics Data System (ADS)

    Toonen, Silvia; Hamers, Adrian; Portegies Zwart, Simon

    2016-12-01

    Field stars are frequently formed in pairs, and many of these binaries are part of triples or even higher-order systems. Even though, the principles of single stellar evolution and binary evolution, have been accepted for a long time, the long-term evolution of stellar triples is poorly understood. The presence of a third star in an orbit around a binary system can significantly alter the evolution of those stars and the binary system. The rich dynamical behaviour in three-body systems can give rise to Lidov-Kozai cycles, in which the eccentricity of the inner orbit and the inclination between the inner and outer orbit vary periodically. In turn, this can lead to an enhancement of tidal effects (tidal friction), gravitational-wave emission and stellar interactions such as mass transfer and collisions. The lack of a self-consistent treatment of triple evolution, including both three-body dynamics as well as stellar evolution, hinders the systematic study and general understanding of the long-term evolution of triple systems. In this paper, we aim to address some of these hiatus, by discussing the dominant physical processes of hierarchical triple evolution, and presenting heuristic recipes for these processes. To improve our understanding on hierarchical stellar triples, these descriptions are implemented in a public source code TrES, which combines three-body dynamics (based on the secular approach) with stellar evolution and their mutual influences. Note that modelling through a phase of stable mass transfer in an eccentric orbit is currently not implemented in TrES, but can be implemented with the appropriate methodology at a later stage.

  10. GENSCHED - A Real World Hierarchical Planning Knowledge-Based System

    NASA Astrophysics Data System (ADS)

    Semeco, Antonio C.; Williams, Bryan D.; Roth, Stefan; Gilmore, John F.

    1986-03-01

    This article describes the design and implementation of GENSCHED, a hierarchical planning system for scheduling production orders in manufacturing facilities.In a typical manufacturing application, orders for the production of certain items arrive continuously and must be scheduled to minimize tardiness, wait-in-process time, and early completion in addition to maximize throughput and resource utilization. In many cases, arriving orders generate manufacturing requirements beyond the capacity of the plant and compromises must be made. Manufacturing operations desire the capability to rearrange the backlog of orders to expedite higher priority ones, and to estimate the effect of newly arriving orders in the current backlog. GENSCHED features a hierarchical planner which takes advantage of the repetitive nature of the plans to efficiently generate valid schedules. A user interface allows manual and automatic scheduling and "what-if" processing of production orders. Finally, a rule-based subsystem for entering and maintaining domain-specific knowledge is exploited to improve schedules and minimize search.

  11. Compiling software for a hierarchical distributed processing system

    DOEpatents

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2013-12-31

    Compiling software for a hierarchical distributed processing system including providing to one or more compiling nodes software to be compiled, wherein at least a portion of the software to be compiled is to be executed by one or more nodes; compiling, by the compiling node, the software; maintaining, by the compiling node, any compiled software to be executed on the compiling node; selecting, by the compiling node, one or more nodes in a next tier of the hierarchy of the distributed processing system in dependence upon whether any compiled software is for the selected node or the selected node's descendents; sending to the selected node only the compiled software to be executed by the selected node or selected node's descendent.

  12. A hierarchical distributed control model for coordinating intelligent systems

    NASA Technical Reports Server (NTRS)

    Adler, Richard M.

    1991-01-01

    A hierarchical distributed control (HDC) model for coordinating cooperative problem-solving among intelligent systems is described. The model was implemented using SOCIAL, an innovative object-oriented tool for integrating heterogeneous, distributed software systems. SOCIAL embeds applications in 'wrapper' objects called Agents, which supply predefined capabilities for distributed communication, control, data specification, and translation. The HDC model is realized in SOCIAL as a 'Manager'Agent that coordinates interactions among application Agents. The HDC Manager: indexes the capabilities of application Agents; routes request messages to suitable server Agents; and stores results in a commonly accessible 'Bulletin-Board'. This centralized control model is illustrated in a fault diagnosis application for launch operations support of the Space Shuttle fleet at NASA, Kennedy Space Center.

  13. A hierarchically distributed architecture for fault isolation expert systems on the space station

    NASA Technical Reports Server (NTRS)

    Miksell, Steve; Coffer, Sue

    1987-01-01

    The Space Station Axiomatic Fault Isolating Expert Systems (SAFTIES) system deals with the hierarchical distribution of control and knowledge among independent expert systems doing fault isolation and scheduling of Space Station subsystems. On its lower level, fault isolation is performed on individual subsystems. These fault isolation expert systems contain knowledge about the performance requirements of their particular subsystem and corrective procedures which may be involved in repsonse to certain performance errors. They can control the functions of equipment in their system and coordinate system task schedules. On a higher level, the Executive contains knowledge of all resources, task schedules for all systems, and the relative priority of all resources and tasks. The executive can override any subsystem task schedule in order to resolve use conflicts or resolve errors that require resources from multiple subsystems. Interprocessor communication is implemented using the SAFTIES Communications Interface (SCI). The SCI is an application layer protocol which supports the SAFTIES distributed multi-level architecture.

  14. Combining information from multiple flood projections in a hierarchical Bayesian framework

    NASA Astrophysics Data System (ADS)

    Le Vine, Nataliya

    2016-04-01

    This study demonstrates, in the context of flood frequency analysis, the potential of a recently proposed hierarchical Bayesian approach to combine information from multiple models. The approach explicitly accommodates shared multimodel discrepancy as well as the probabilistic nature of the flood estimates, and treats the available models as a sample from a hypothetical complete (but unobserved) set of models. The methodology is applied to flood estimates from multiple hydrological projections (the Future Flows Hydrology data set) for 135 catchments in the UK. The advantages of the approach are shown to be: (1) to ensure adequate "baseline" with which to compare future changes; (2) to reduce flood estimate uncertainty; (3) to maximize use of statistical information in circumstances where multiple weak predictions individually lack power, but collectively provide meaningful information; (4) to diminish the importance of model consistency when model biases are large; and (5) to explicitly consider the influence of the (model performance) stationarity assumption. Moreover, the analysis indicates that reducing shared model discrepancy is the key to further reduction of uncertainty in the flood frequency analysis. The findings are of value regarding how conclusions about changing exposure to flooding are drawn, and to flood frequency change attribution studies.

  15. Dynamic Non-Hierarchical File Systems for Exascale Storage

    SciTech Connect

    Long, Darrell E.; Miller, Ethan L

    2015-02-24

    This constitutes the final report for “Dynamic Non-Hierarchical File Systems for Exascale Storage”. The ultimate goal of this project was to improve data management in scientific computing and high-end computing (HEC) applications, and to achieve this goal we proposed: to develop the first, HEC-targeted, file system featuring rich metadata and provenance collection, extreme scalability, and future storage hardware integration as core design goals, and to evaluate and develop a flexible non-hierarchical file system interface suitable for providing more powerful and intuitive data management interfaces to HEC and scientific computing users. Data management is swiftly becoming a serious problem in the scientific community – while copious amounts of data are good for obtaining results, finding the right data is often daunting and sometimes impossible. Scientists participating in a Department of Energy workshop noted that most of their time was spent “...finding, processing, organizing, and moving data and it’s going to get much worse”. Scientists should not be forced to become data mining experts in order to retrieve the data they want, nor should they be expected to remember the naming convention they used several years ago for a set of experiments they now wish to revisit. Ideally, locating the data you need would be as easy as browsing the web. Unfortunately, existing data management approaches are usually based on hierarchical naming, a 40 year-old technology designed to manage thousands of files, not exabytes of data. Today’s systems do not take advantage of the rich array of metadata that current high-end computing (HEC) file systems can gather, including content-based metadata and provenance1 information. As a result, current metadata search approaches are typically ad hoc and often work by providing a parallel management system to the “main” file system, as is done in Linux (the locate utility), personal computers, and enterprise search

  16. Secular Orbital Dynamics of Hierarchical Two-planet Systems

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri; Ford, Eric B.

    2010-06-01

    The discovery of multi-planet extrasolar systems has kindled interest in using their orbital evolution as a probe of planet formation. Accurate descriptions of planetary orbits identify systems that could hide additional planets or be in a special dynamical state, and inform targeted follow-up observations. We combine published radial velocity data with Markov Chain Monte Carlo analyses in order to obtain an ensemble of masses, semimajor axes, eccentricities, and orbital angles for each of the five dynamically active multi-planet systems: HD 11964, HD 38529, HD 108874, HD 168443, and HD 190360. We dynamically evolve these systems using 52,000 long-term N-body integrations that sample the full range of possible line-of-sight and relative inclinations, and we report on the system stability, secular evolution, and the extent of the resonant interactions. We find that planetary orbits in hierarchical systems exhibit complex dynamics and can become highly eccentric and maybe significantly inclined. Additionally, we incorporate the effects of general relativity in the long-term simulations and demonstrate that it can qualitatively affect the dynamics of some systems with high relative inclinations. The simulations quantify the likelihood of different dynamical regimes for each system and highlight the dangers of restricting simulation phase space to a single set of initial conditions or coplanar orbits.

  17. SECULAR ORBITAL DYNAMICS OF HIERARCHICAL TWO-PLANET SYSTEMS

    SciTech Connect

    Veras, Dimitri; Ford, Eric B.

    2010-06-01

    The discovery of multi-planet extrasolar systems has kindled interest in using their orbital evolution as a probe of planet formation. Accurate descriptions of planetary orbits identify systems that could hide additional planets or be in a special dynamical state, and inform targeted follow-up observations. We combine published radial velocity data with Markov Chain Monte Carlo analyses in order to obtain an ensemble of masses, semimajor axes, eccentricities, and orbital angles for each of the five dynamically active multi-planet systems: HD 11964, HD 38529, HD 108874, HD 168443, and HD 190360. We dynamically evolve these systems using 52,000 long-term N-body integrations that sample the full range of possible line-of-sight and relative inclinations, and we report on the system stability, secular evolution, and the extent of the resonant interactions. We find that planetary orbits in hierarchical systems exhibit complex dynamics and can become highly eccentric and maybe significantly inclined. Additionally, we incorporate the effects of general relativity in the long-term simulations and demonstrate that it can qualitatively affect the dynamics of some systems with high relative inclinations. The simulations quantify the likelihood of different dynamical regimes for each system and highlight the dangers of restricting simulation phase space to a single set of initial conditions or coplanar orbits.

  18. Requirements for implementing real-time control functional modules on a hierarchical parallel pipelined system

    NASA Technical Reports Server (NTRS)

    Wheatley, Thomas E.; Michaloski, John L.; Lumia, Ronald

    1989-01-01

    Analysis of a robot control system leads to a broad range of processing requirements. One fundamental requirement of a robot control system is the necessity of a microcomputer system in order to provide sufficient processing capability.The use of multiple processors in a parallel architecture is beneficial for a number of reasons, including better cost performance, modular growth, increased reliability through replication, and flexibility for testing alternate control strategies via different partitioning. A survey of the progression from low level control synchronizing primitives to higher level communication tools is presented. The system communication and control mechanisms of existing robot control systems are compared to the hierarchical control model. The impact of this design methodology on the current robot control systems is explored.

  19. A Hierarchical Statistic Methodology for Advanced Memory System Evaluation

    SciTech Connect

    Sun, X.-J.; He, D.; Cameron, K.W.; Luo, Y.

    1999-04-12

    Advances in technology have resulted in a widening of the gap between computing speed and memory access time. Data access time has become increasingly important for computer system design. Various hierarchical memory architectures have been developed. The performance of these advanced memory systems, however, varies with applications and problem sizes. How to reach an optimal cost/performance design eludes researchers still. In this study, the authors introduce an evaluation methodology for advanced memory systems. This methodology is based on statistical factorial analysis and performance scalability analysis. It is two fold: it first determines the impact of memory systems and application programs toward overall performance; it also identifies the bottleneck in a memory hierarchy and provides cost/performance comparisons via scalability analysis. Different memory systems can be compared in terms of mean performance or scalability over a range of codes and problem sizes. Experimental testing has been performed extensively on the Department of Energy's Accelerated Strategic Computing Initiative (ASCI) machines and benchmarks available at the Los Alamos National Laboratory to validate this newly proposed methodology. Experimental and analytical results show this methodology is simple and effective. It is a practical tool for memory system evaluation and design. Its extension to general architectural evaluation and parallel computer systems are possible and should be further explored.

  20. Universality classes of fluctuation dynamics in hierarchical complex systems

    NASA Astrophysics Data System (ADS)

    Macêdo, A. M. S.; González, Iván R. Roa; Salazar, D. S. P.; Vasconcelos, G. L.

    2017-03-01

    A unified approach is proposed to describe the statistics of the short-time dynamics of multiscale complex systems. The probability density function of the relevant time series (signal) is represented as a statistical superposition of a large time-scale distribution weighted by the distribution of certain internal variables that characterize the slowly changing background. The dynamics of the background is formulated as a hierarchical stochastic model whose form is derived from simple physical constraints, which in turn restrict the dynamics to only two possible classes. The probability distributions of both the signal and the background have simple representations in terms of Meijer G functions. The two universality classes for the background dynamics manifest themselves in the signal distribution as two types of tails: power law and stretched exponential, respectively. A detailed analysis of empirical data from classical turbulence and financial markets shows excellent agreement with the theory.

  1. Hierarchical cooperative control for multiagent systems with switching directed topologies.

    PubMed

    Hu, Jianqiang; Cao, Jinde

    2015-10-01

    The hierarchical cooperative control problem is concerned for a two-layer networked multiagent system under switching directed topologies. The group cooperative objective is to achieve finite-time formation control for the upper layer of leaders and containment control for the lower layer of followers. Two kinds of cooperative strategies, including centralized-distributed control and distributed-distributed control, are proposed for two types of switching laws: 1) random switching law with the dwell time and 2) Markov switching law with stationary distribution. Utilizing the state transition matrix methods and matrix measure techniques, some sufficient conditions are derived for asymptotical containment control and exponential almost sure containment control, respectively. Finally, some numerical examples are provided to demonstrate the effectiveness of the proposed control schemes.

  2. Automated control of hierarchical systems using value-driven methods

    NASA Technical Reports Server (NTRS)

    Pugh, George E.; Burke, Thomas E.

    1990-01-01

    An introduction is given to the Value-driven methodology, which has been successfully applied to solve a variety of difficult decision, control, and optimization problems. Many real-world decision processes (e.g., those encountered in scheduling, allocation, and command and control) involve a hierarchy of complex planning considerations. For such problems it is virtually impossible to define a fixed set of rules that will operate satisfactorily over the full range of probable contingencies. Decision Science Applications' value-driven methodology offers a systematic way of automating the intuitive, common-sense approach used by human planners. The inherent responsiveness of value-driven systems to user-controlled priorities makes them particularly suitable for semi-automated applications in which the user must remain in command of the systems operation. Three examples of the practical application of the approach in the automation of hierarchical decision processes are discussed: the TAC Brawler air-to-air combat simulation is a four-level computerized hierarchy; the autonomous underwater vehicle mission planning system is a three-level control system; and the Space Station Freedom electrical power control and scheduling system is designed as a two-level hierarchy. The methodology is compared with rule-based systems and with other more widely-known optimization techniques.

  3. Design And Implementation Of A Hierarchical Automated Inspection System

    NASA Astrophysics Data System (ADS)

    Tarbox, Glenn H.; Gerhardt, Lester A.

    1990-02-01

    In order to provide a framework for the evaluation of, and need for, sensor information appropriate to real time manufacturing control, a workcell based on a 5-axis machining center was developed. This workcell defines a problem space within which automated inspection is to be applied. Primarily, we are interested in evaluating the use of machine vision and Coordinate Measuring Machines (CMM's) as means to provide information to an automated workcell controller. This controller will use these sensing technologies in a hierarchical fashion exploiting the speed vs. accuracy tradeoff's characteristic of tactile and non-tactile coordinate acquisition. We have implemented an Octree solid modeling system which has the capabilities of model generation from the information provided by the vision system. In addition, the Octree method lends itself to simulating the actual manufacturing process. Our system reads the machine tool G-Codes generated by our CAD system and simulates the material removal operation by successively removing intersections between the tool and workpiece. This machined model is then used for automatic inspection sequence generation. This paper will describe the framework and architecture of our automated inspection system, as well as specifics relating to the Octree modeling system.

  4. Ordered assembly of NiCo₂O₄ multiple hierarchical structures for high-performance pseudocapacitors.

    PubMed

    Zhou, Qingwen; Xing, Jiachao; Gao, Yanfang; Lv, Xiaojun; He, Yongmei; Guo, Zihan; Li, Yueming

    2014-07-23

    The design and development of nanomaterials has become central to the advancement of pseudocapacitive performance. Many one-dimensional nanostructures (1D NSs), two-dimensional nanostructures (2D NSs), and three-dimensional hierarchical structures (3D HSs) composed of these building blocks have been synthesized as pseudocapacitive materials via different methods. However, due to the unclear assembly mechanism of these NSs, reports of HSs simultaneously assembled from two or more types of NSs are rare. In this article, NiCo2O4 multiple hierarchical structures (MHSs) composed of 1D nanowires and 2D nanosheets are simply grown on Ni foam using an ordered two-step hydrothermal synthesis followed by annealing processing. The low-dimensional nanowire is found to hold priority in the growth order, rather than the high-dimensional nanosheet, thus effectively promoting the integration of these different NSs in the assembly of the NiCo2O4 MHSs. With vast electroactive surface area and favorable mesoporous architecture, the NiCo2O4 MHSs exhibit a high specific capacitance of up to 2623.3 F g(-1), scaled to the active mass of the NiCo2O4 sample at a current density of 1 A g(-1). A nearly constant rate performance of 68% is achieved at a current density ranging from 1 to 40 A g(-1), and the sample retains approximately 94% of its maximum capacitance even after 3000 continuous charge-discharge cycles at a consistently high current density of 10 A g(-1).

  5. HAL: a hierarchical format for storing and analyzing multiple genome alignments.

    PubMed

    Hickey, Glenn; Paten, Benedict; Earl, Dent; Zerbino, Daniel; Haussler, David

    2013-05-15

    Large multiple genome alignments and inferred ancestral genomes are ideal resources for comparative studies of molecular evolution, and advances in sequencing and computing technology are making them increasingly obtainable. These structures can provide a rich understanding of the genetic relationships between all subsets of species they contain. Current formats for storing genomic alignments, such as XMFA and MAF, are all indexed or ordered using a single reference genome, however, which limits the information that can be queried with respect to other species and clades. This loss of information grows with the number of species under comparison, as well as their phylogenetic distance. We present HAL, a compressed, graph-based hierarchical alignment format for storing multiple genome alignments and ancestral reconstructions. HAL graphs are indexed on all genomes they contain. Furthermore, they are organized phylogenetically, which allows for modular and parallel access to arbitrary subclades without fragmentation because of rearrangements that have occurred in other lineages. HAL graphs can be created or read with a comprehensive C++ API. A set of tools is also provided to perform basic operations, such as importing and exporting data, identifying mutations and coordinate mapping (liftover). All documentation and source code for the HAL API and tools are freely available at http://github.com/glennhickey/hal. hickey@soe.ucsc.edu or haussler@soe.ucsc.edu Supplementary data are available at Bioinformatics online.

  6. Hierarchical, Three-Dimensional Measurement System for Crime Scene Scanning.

    PubMed

    Marcin, Adamczyk; Maciej, Sieniło; Robert, Sitnik; Adam, Woźniak

    2017-02-02

    We present a new generation of three-dimensional (3D) measuring systems, developed for the process of crime scene documentation. This measuring system facilitates the preparation of more insightful, complete, and objective documentation for crime scenes. Our system reflects the actual requirements for hierarchical documentation, and it consists of three independent 3D scanners: a laser scanner for overall measurements, a situational structured light scanner for more minute measurements, and a detailed structured light scanner for the most detailed parts of tscene. Each scanner has its own spatial resolution, of 2.0, 0.3, and 0.05 mm, respectively. The results of interviews we have conducted with technicians indicate that our developed 3D measuring system has significant potential to become a useful tool for forensic technicians. To ensure the maximum compatibility of our measuring system with the standards that regulate the documentation process, we have also performed a metrological validation and designated the maximum permissible length measurement error EMPE for each structured light scanner. In this study, we present additional results regarding documentation processes conducted during crime scene inspections and a training session.

  7. Hierarchical sampling of multiple strata: an innovative technique in exposure characterization.

    PubMed

    Ericson, Jonathon E; Gonzalez, Elisabeth J

    2003-07-01

    Sampling of multiple strata, or hierarchical sampling of various exposure sources and activity areas, has been tested and is suggested as a method to sample (or to locate) areas with a high prevalence of elevated blood lead in children. Hierarchical sampling was devised to supplement traditional soil lead sampling of a single stratum, either residential or fixed point source, using a multistep strategy. Blood lead (n=1141) and soil lead (n=378) data collected under the USEPA/UCI Tijuana Lead Project (1996-1999) were analyzed to evaluate the usefulness of sampling soil lead from background sites, schools and parks, point sources, and residences. Results revealed that industrial emissions have been a contributing factor to soil lead contamination in Tijuana. At the regional level, point source soil lead was associated with mean blood lead levels and concurrent high background, and point source soil lead levels were predictive of a high percentage of subjects with blood lead equal to or greater than 10 micro g/dL (pe 10). Significant relationships were observed between mean blood lead level and fixed point source soil lead (r=0.93; P<0.05; R(2)=0.72 using a quadratic model) and between residential soil lead and fixed point source soil lead (r=0.90; P<0.05; R(2)=0.86 using a cubic model). This study suggests that point sources alone are not sufficient for predicting the relative risk of exposure to lead in the urban environment. These findings will be useful in defining regions for targeted or universal soil lead sampling by site type. Point sources have been observed to be predictive of mean blood lead at the regional level; however, this relationship alone was not sufficient to predict pe 10. It is concluded that when apparently undisturbed sites reveal high soil lead levels in addition to local point sources, dispersion of lead is widespread and will be associated with a high prevalence of elevated blood lead in children. Multiple strata sampling was shown to be

  8. Effective parameters determining the information flow in hierarchical biological systems.

    PubMed

    Blöchl, Florian; Wittmann, Dominik M; Theis, Fabian J

    2011-04-01

    Signaling networks are abundant in higher organisms. They play pivotal roles, e.g., during embryonic development or within the immune system. In this contribution, we study the combined effect of the various kinetic parameters on the dynamics of signal transduction. To this end, we consider hierarchical complex systems as prototypes of signaling networks. For given topology, the output of these networks is determined by an interplay of the single parameters. For different kinetics, we describe this by algebraic expressions, the so-called effective parameters.When modeling switch-like interactions by Heaviside step functions, we obtain these effective parameters recursively from the interaction graph. They can be visualized as directed trees, which allows us to easily determine the global effect of single kinetic parameters on the system's behavior. We provide evidence that these results generalize to sigmoidal Hill kinetics.In the case of linear activation functions, we again show that the algebraic expressions can be immediately inferred from the topology of the interaction network. This allows us to transform time-consuming analytic solutions of differential equations into a simple graph-theoretic problem. In this context, we also discuss the impact of our work on parameter estimation problems. An issue is that even the fitting of identifiable effective parameters often turns out to be numerically ill-conditioned. We demonstrate that this fitting problem can be reformulated as the problem of fitting exponential sums, for which robust algorithms exist.

  9. Simultaneous estimation of multiple quantitative trait loci and growth curve parameters through hierarchical Bayesian modeling

    PubMed Central

    Sillanpää, M J; Pikkuhookana, P; Abrahamsson, S; Knürr, T; Fries, A; Lerceteau, E; Waldmann, P; García-Gil, M R

    2012-01-01

    A novel hierarchical quantitative trait locus (QTL) mapping method using a polynomial growth function and a multiple-QTL model (with no dependence in time) in a multitrait framework is presented. The method considers a population-based sample where individuals have been phenotyped (over time) with respect to some dynamic trait and genotyped at a given set of loci. A specific feature of the proposed approach is that, instead of an average functional curve, each individual has its own functional curve. Moreover, each QTL can modify the dynamic characteristics of the trait value of an individual through its influence on one or more growth curve parameters. Apparent advantages of the approach include: (1) assumption of time-independent QTL and environmental effects, (2) alleviating the necessity for an autoregressive covariance structure for residuals and (3) the flexibility to use variable selection methods. As a by-product of the method, heritabilities and genetic correlations can also be estimated for individual growth curve parameters, which are considered as latent traits. For selecting trait-associated loci in the model, we use a modified version of the well-known Bayesian adaptive shrinkage technique. We illustrate our approach by analysing a sub sample of 500 individuals from the simulated QTLMAS 2009 data set, as well as simulation replicates and a real Scots pine (Pinus sylvestris) data set, using temporal measurements of height as dynamic trait of interest. PMID:21792229

  10. Hierarchical inverse Gaussian models and multiple testing: application to gene expression data.

    PubMed

    Labbe, Aurelie; Thompson, Mary

    2005-01-01

    Detecting differentially expressed genes in microarray experiments is a topic that has been well studied in the literature. Many hypothesis testing methods have been proposed that rely on strong distributional assumptions for the gene intensities. However, the shape of microarray data may vary substantially from one experiment to another, and model assumptions may be seriously violated in many cases. The literature on microarray data is mainly based on two distributions: the log-normal and the gamma distributions, that often appear to be effective when used in a Bayesian hierarchical framework. However, if a model that fits the data well in a global manner seems attractive, two points should be regarded with attention: the ability of the model to fit the tail of the observed distribution, and its robustness to a wrong specification of the model, in terms of error rates for the hypothesis tests. In order to focus on these aspects, we propose to use Bayesian models involving the inverse Gaussian distribution to describe gene expression data. We show that these models can be good competitors to the traditional Bayesian or random effect gamma or log-normal models in some situations. A multiple testing procedure is then proposed, based on an asymptotic property of the posterior probability of the one-sided alternative hypothesis. We show that the asymptotic property is well approximated for inverse Gaussian models, even when the number of observations available for each test is very small.

  11. Cockles, barnacles and ascidians compose a subtidal facilitation cascade with multiple hierarchical levels of foundation species.

    PubMed

    Yakovis, Eugeniy; Artemieva, Anna

    2017-03-22

    Facilitation cascades occur when multiple foundation species in a community are involved in a hierarchy of positive interactions, and consist of a primary facilitator which positively affects secondary facilitators, each supporting a suit of dependent species. There is no theoretical limit to the number of levels in a facilitation cascade, yet the existence of more than two has rarely been examined. We manipulated biogenic substrate produced by a primary facilitator (cockle shells) and a secondary facilitator (barnacles and their empty tests) in a space-limited subtidal community to test the hypothesis that solitary ascidians would be the third-level facilitator. In the field, most ascidians were found on barnacles, and most barnacles occupied cockle shells. To produce this pattern, barnacles could nurse ascidians (a longer 'facilitation chain') or outcompete them from cockle shells (a shorter chain). Experimental results clearly supported the nursing hypothesis providing evidence for a facilitation cascade with three hierarchical levels of foundation species. Our findings confirm that like predation and competition, positive interspecific interactions nest into multi-tier hierarchies with numerous levels. While the number of foundation species should increase community stability and resilience as it increases diversity and reduces environmental stress, facilitation chain length may have the opposite effect.

  12. Tensegrity I. Cell structure and hierarchical systems biology

    NASA Technical Reports Server (NTRS)

    Ingber, Donald E.

    2003-01-01

    In 1993, a Commentary in this journal described how a simple mechanical model of cell structure based on tensegrity architecture can help to explain how cell shape, movement and cytoskeletal mechanics are controlled, as well as how cells sense and respond to mechanical forces (J. Cell Sci. 104, 613-627). The cellular tensegrity model can now be revisited and placed in context of new advances in our understanding of cell structure, biological networks and mechanoregulation that have been made over the past decade. Recent work provides strong evidence to support the use of tensegrity by cells, and mathematical formulations of the model predict many aspects of cell behavior. In addition, development of the tensegrity theory and its translation into mathematical terms are beginning to allow us to define the relationship between mechanics and biochemistry at the molecular level and to attack the larger problem of biological complexity. Part I of this two-part article covers the evidence for cellular tensegrity at the molecular level and describes how this building system may provide a structural basis for the hierarchical organization of living systems--from molecule to organism. Part II, which focuses on how these structural networks influence information processing networks, appears in the next issue.

  13. Hierarchical Recognition Scheme for Human Facial Expression Recognition Systems

    PubMed Central

    Siddiqi, Muhammad Hameed; Lee, Sungyoung; Lee, Young-Koo; Khan, Adil Mehmood; Truc, Phan Tran Ho

    2013-01-01

    Over the last decade, human facial expressions recognition (FER) has emerged as an important research area. Several factors make FER a challenging research problem. These include varying light conditions in training and test images; need for automatic and accurate face detection before feature extraction; and high similarity among different expressions that makes it difficult to distinguish these expressions with a high accuracy. This work implements a hierarchical linear discriminant analysis-based facial expressions recognition (HL-FER) system to tackle these problems. Unlike the previous systems, the HL-FER uses a pre-processing step to eliminate light effects, incorporates a new automatic face detection scheme, employs methods to extract both global and local features, and utilizes a HL-FER to overcome the problem of high similarity among different expressions. Unlike most of the previous works that were evaluated using a single dataset, the performance of the HL-FER is assessed using three publicly available datasets under three different experimental settings: n-fold cross validation based on subjects for each dataset separately; n-fold cross validation rule based on datasets; and, finally, a last set of experiments to assess the effectiveness of each module of the HL-FER separately. Weighted average recognition accuracy of 98.7% across three different datasets, using three classifiers, indicates the success of employing the HL-FER for human FER. PMID:24316568

  14. HiCoDG: a hierarchical data-gathering scheme using cooperative multiple mobile elements.

    PubMed

    Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

    2014-12-17

    In this paper, we study mobile element (ME)-based data-gathering schemes in wireless sensor networks. Due to the physical speed limits of mobile elements, the existing data-gathering schemes that use mobile elements can suffer from high data-gathering latency. In order to address this problem, this paper proposes a new hierarchical and cooperative data-gathering (HiCoDG) scheme that enables multiple mobile elements to cooperate with each other to collect and relay data. In HiCoDG, two types of mobile elements are used: the mobile collector (MC) and the mobile relay (MR). MCs collect data from sensors and forward them to the MR, which will deliver them to the sink. In this work, we also formulated an integer linear programming (ILP) optimization problem to find the optimal trajectories for MCs and the MR, such that the traveling distance of MEs is minimized. Two variants of HiCoDG, intermediate station (IS)-based and cooperative movement scheduling (CMS)-based, are proposed to facilitate cooperative data forwarding from MCs to the MR. An analytical model for estimating the average data-gathering latency in HiCoDG was also designed. Simulations were performed to compare the performance of the IS and CMS variants, as well as a multiple traveling salesman problem (mTSP)-based approach. The simulation results show that HiCoDG outperforms mTSP in terms of latency. The results also show that CMS can achieve the lowest latency with low energy consumption.

  15. HiCoDG: A Hierarchical Data-Gathering Scheme Using Cooperative Multiple Mobile Elements †

    PubMed Central

    Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

    2014-01-01

    In this paper, we study mobile element (ME)-based data-gathering schemes in wireless sensor networks. Due to the physical speed limits of mobile elements, the existing data-gathering schemes that use mobile elements can suffer from high data-gathering latency. In order to address this problem, this paper proposes a new hierarchical and cooperative data-gathering (HiCoDG) scheme that enables multiple mobile elements to cooperate with each other to collect and relay data. In HiCoDG, two types of mobile elements are used: the mobile collector (MC) and the mobile relay (MR). MCs collect data from sensors and forward them to the MR, which will deliver them to the sink. In this work, we also formulated an integer linear programming (ILP) optimization problem to find the optimal trajectories for MCs and the MR, such that the traveling distance of MEs is minimized. Two variants of HiCoDG, intermediate station (IS)-based and cooperative movement scheduling (CMS)-based, are proposed to facilitate cooperative data forwarding from MCs to the MR. An analytical model for estimating the average data-gathering latency in HiCoDG was also designed. Simulations were performed to compare the performance of the IS and CMS variants, as well as a multiple traveling salesman problem (mTSP)-based approach. The simulation results show that HiCoDG outperforms mTSP in terms of latency. The results also show that CMS can achieve the lowest latency with low energy consumption. PMID:25526356

  16. Interactive realization system of visual reality using hierarchical model-driven concurrent processing

    NASA Astrophysics Data System (ADS)

    Enomoto, Hajime; Murao, Yo

    1998-04-01

    To realize and integrate various kinds of media information with the least data, a new hierarchical software architecture has been developed. Aiming at easier manipulation, this system is based on a model driven method. Four kinds of generic models; data, object, role, and process models are employed in this system. These models have hierarchical interfaces from data to process layers. In case of the data model, attribute values of data are defined in template forms. If necessary, several constraints are attached to them. In the object model case, every object is defined by `formal' and `feature' structures. Formal structures are defined by our object network which is composed of noun and verb objects. Feature structures are mainly composed of a set of properties, which are described by constraints. For the role model, schemes of various levels of coordination relating multiple roles are represented to satisfy their intentions. These structures are defined by generic goals and constraints. The process model is designed so that all roles are executed concurrently in order to satisfy their interactive intentions under cooperative or competitive conditions. Integrated results of various media can be provided by using or Extensible WELL (Window-based Elaboration Language) system.

  17. Scale of association: hierarchical linear models and the measurement of ecological systems

    Treesearch

    Sean M. McMahon; Jeffrey M. Diez

    2007-01-01

    A fundamental challenge to understanding patterns in ecological systems lies in employing methods that can analyse, test and draw inference from measured associations between variables across scales. Hierarchical linear models (HLM) use advanced estimation algorithms to measure regression relationships and variance-covariance parameters in hierarchically structured...

  18. Automated Hierarchical to CODASYL (Conference on Data Systems Languages) Database Interface Schema Translator.

    DTIC Science & Technology

    1983-12-16

    Introduction....... ... .. .. .. .. .... 1 1 Background.................................-I Hierarchical Approach.... .. .. ........ 5 Network Approach...Database . .. I - 2 " I - 2 A Network View of a Database ..... I - 3 I - 3 A Relational View of a Database . . . . I - 4 II - I Context Diagram for this...independence. Database Management Systems are classified into three major models; relational, network , and hierarchical. Each model uses a software

  19. Time and temperature dependent multiple hierarchical NiCo2O4 for high-performance supercapacitors.

    PubMed

    Wang, Shen; Sun, Shumin; Li, Shaodan; Gong, Feilong; Li, Yannan; Wu, Qiong; Song, Pei; Fang, Shaoming; Wang, Peiyuan

    2016-05-07

    A multiple hierarchical NiCo2O4 (denoted as P-100), which was constructed of nanosheets covered with nanowires, was obtained by a facial hydrothermal method in combination with annealing treatment at 300 °C. The hydrothermal temperature and reaction time play key roles in the formation of the unique hierarchical NiCo2O4 based on the morphology evolution. As a supercapacitor electrode material, the obtained P-100 displays a high specific capacitance of 1393 F g(-1) at 0.5 A g(-1). Furthermore, the assembled P-100//AC asymmetric supercapacitor demonstrates a high energy density (21.4 Wh kg(-1)) at a power density of 350 W kg(-1) and remarkable cycling stability. The good electrochemical performances of the P-100 are mainly due to its three dimensional hierarchical porous nanostructure and high specific surface area as well as the synergetic effect of the nanosheets and nanowires in NiCo2O4. The experimental results demonstrated that the multiple hierarchical NiCo2O4 is a promising electrode material for high-performance supercapacitors.

  20. Hierarchical RFI Mitigation System at the Mauritius Radio Telescope

    NASA Astrophysics Data System (ADS)

    Udaya Shankar, N.; Pandey, V. N.

    2006-08-01

    In this paper, we present salient features of the hierarchical RFI mitigation system developed and implemented for offline processing of the visibilities recorded at MRT. Its aim is to achieve effective, reliable and non-toxic automatic RFI mitigation with minimal human intervention. RFI poses a serious problem at MRT due to its low frequency of operation, wide primary beam  (EWxNS~2°x56°) and large amount of data collected for a low frequency survey. Even though several signal processing methods are used to handle RFI, in practice there is no universal foolproof technique. The developed system uses a conjunction of a variety of techniques involving linear and non-linear methods in the visibility as well as in the image domain. These include Thresholding, Fourier filtering, Hampel filtering, Model fitting, Visual inspection, multi-parameter decision based algorithm which uses cumulative interference statistics, and the fact that the sky signal is correlated in each day's images but interference is most likely not. More than 99.7% of the interference is detected automatically, the remaining is detected by semi-automatic methods. The images obtained after applying the RFI mitigation system are free from any perceivable interference and demonstrate its effectiveness. The principles and techniques used in the RFI mitigation system are of general nature. We believe that such an approach based on a conjunction of techniques exploiting their natural strengths and judiciously applying them at various stages of data processing is an important step in the future direction of research to accomplish the ultimate goal of achieving completely automatic data flagging. Use of an RFI database is valuable to investigate the nature of interference at an observatory site and develop appropriate techniques based on its statistics for its mitigation. The 20,000 hours of astronomical observations for the MRT survey have been used for such an analysis. The interesting aspects of

  1. Predictability of extremes in non-linear hierarchically organized systems

    NASA Astrophysics Data System (ADS)

    Kossobokov, V. G.; Soloviev, A.

    2011-12-01

    Understanding the complexity of non-linear dynamics of hierarchically organized systems progresses to new approaches in assessing hazard and risk of the extreme catastrophic events. In particular, a series of interrelated step-by-step studies of seismic process along with its non-stationary though self-organized behaviors, has led already to reproducible intermediate-term middle-range earthquake forecast/prediction technique that has passed control in forward real-time applications during the last two decades. The observed seismic dynamics prior to and after many mega, great, major, and strong earthquakes demonstrate common features of predictability and diverse behavior in course durable phase transitions in complex hierarchical non-linear system of blocks-and-faults of the Earth lithosphere. The confirmed fractal nature of earthquakes and their distribution in space and time implies that many traditional estimations of seismic hazard (from term-less to short-term ones) are usually based on erroneous assumptions of easy tractable analytical models, which leads to widespread practice of their deceptive application. The consequences of underestimation of seismic hazard propagate non-linearly into inflicted underestimation of risk and, eventually, into unexpected societal losses due to earthquakes and associated phenomena (i.e., collapse of buildings, landslides, tsunamis, liquefaction, etc.). The studies aimed at forecast/prediction of extreme events (interpreted as critical transitions) in geophysical and socio-economical systems include: (i) large earthquakes in geophysical systems of the lithosphere blocks-and-faults, (ii) starts and ends of economic recessions, (iii) episodes of a sharp increase in the unemployment rate, (iv) surge of the homicides in socio-economic systems. These studies are based on a heuristic search of phenomena preceding critical transitions and application of methodologies of pattern recognition of infrequent events. Any study of rare

  2. Adaptive variable structure hierarchical fuzzy control for a class of high-order nonlinear dynamic systems.

    PubMed

    Mansouri, Mohammad; Teshnehlab, Mohammad; Aliyari Shoorehdeli, Mahdi

    2015-05-01

    In this paper, a novel adaptive hierarchical fuzzy control system based on the variable structure control is developed for a class of SISO canonical nonlinear systems in the presence of bounded disturbances. It is assumed that nonlinear functions of the systems be completely unknown. Switching surfaces are incorporated into the hierarchical fuzzy control scheme to ensure the system stability. A fuzzy soft switching system decides the operation area of the hierarchical fuzzy control and variable structure control systems. All the nonlinearly appeared parameters of conclusion parts of fuzzy blocks located in different layers of the hierarchical fuzzy control system are adjusted through adaptation laws deduced from the defined Lyapunov function. The proposed hierarchical fuzzy control system reduces the number of rules and consequently the number of tunable parameters with respect to the ordinary fuzzy control system. Global boundedness of the overall adaptive system and the desired precision are achieved using the proposed adaptive control system. In this study, an adaptive hierarchical fuzzy system is used for two objectives; it can be as a function approximator or a control system based on an intelligent-classic approach. Three theorems are proven to investigate the stability of the nonlinear dynamic systems. The important point about the proposed theorems is that they can be applied not only to hierarchical fuzzy controllers with different structures of hierarchical fuzzy controller, but also to ordinary fuzzy controllers. Therefore, the proposed algorithm is more general. To show the effectiveness of the proposed method four systems (two mechanical, one mathematical and one chaotic) are considered in simulations. Simulation results demonstrate the validity, efficiency and feasibility of the proposed approach to control of nonlinear dynamic systems. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Hierarchical and Parallelizable Direct Volume Rendering for Irregular and Multiple Grids

    NASA Technical Reports Server (NTRS)

    Wilhelms, Jane; VanGelder, Allen; Tarantino, Paul; Gibbs, Jonathan

    1996-01-01

    A general volume rendering technique is described that efficiently produces images of excellent quality from data defined over irregular grids having a wide variety of formats. Rendering is done in software, eliminating the need for special graphics hardware, as well as any artifacts associated with graphics hardware. Images of volumes with about one million cells can be produced in one to several minutes on a workstation with a 150 MHz processor. A significant advantage of this method for applications such as computational fluid dynamics is that it can process multiple intersecting grids. Such grids present problems for most current volume rendering techniques. Also, the wide range of cell sizes (by a factor of 10,000 or more), which is typical of such applications, does not present difficulties, as it does for many techniques. A spatial hierarchical organization makes it possible to access data from a restricted region efficiently. The tree has greater depth in regions of greater detail, determined by the number of cells in the region. It also makes it possible to render useful 'preview' images very quickly (about one second for one-million-cell grids) by displaying each region associated with a tree node as one cell. Previews show enough detail to navigate effectively in very large data sets. The algorithmic techniques include use of a kappa-d tree, with prefix-order partitioning of triangles, to reduce the number of primitives that must be processed for one rendering, coarse-grain parallelism for a shared-memory MIMD architecture, a new perspective transformation that achieves greater numerical accuracy, and a scanline algorithm with depth sorting and a new clipping technique.

  4. Hierarchical Bayesian inference for HIV dynamic differential equation models incorporating multiple treatment factors.

    PubMed

    Huang, Yangxin; Wu, Hulin; Acosta, Edward P

    2010-08-01

    Studies on HIV dynamics in AIDS research are very important in understanding the pathogenesis of HIV-1 infection and also in assessing the effectiveness of antiretroviral (ARV) treatment. Viral dynamic models can be formulated through a system of nonlinear ordinary differential equations (ODE), but there has been only limited development of statistical methodologies for inference. This article, motivated by an AIDS clinical study, discusses a hierarchical Bayesian nonlinear mixed-effects modeling approach to dynamic ODE models without a closed-form solution. In this model, we fully integrate viral load, medication adherence, drug resistance, pharmacokinetics, baseline covariates and time-dependent drug efficacy into the data analysis for characterizing long-term virologic responses. Our method is implemented by a data set from an AIDS clinical study. The results suggest that modeling HIV dynamics and virologic responses with consideration of time-varying clinical factors as well as baseline characteristics may be important for HIV/AIDS studies in providing quantitative guidance to better understand the virologic responses to ARV treatment and to help the evaluation of clinical trial design in response to existing therapies.

  5. Hierarchical control of procedural and declarative category-learning systems.

    PubMed

    Turner, Benjamin O; Crossley, Matthew J; Ashby, F Gregory

    2017-04-15

    Substantial evidence suggests that human category learning is governed by the interaction of multiple qualitatively distinct neural systems. In this view, procedural memory is used to learn stimulus-response associations, and declarative memory is used to apply explicit rules and test hypotheses about category membership. However, much less is known about the interaction between these systems: how is control passed between systems as they interact to influence motor resources? Here, we used fMRI to elucidate the neural correlates of switching between procedural and declarative categorization systems. We identified a key region of the cerebellum (left Crus I) whose activity was bidirectionally modulated depending on switch direction. We also identified regions of the default mode network (DMN) that were selectively connected to left Crus I during switching. We propose that the cerebellum-in coordination with the DMN-serves a critical role in passing control between procedural and declarative memory systems.

  6. A hierarchical voltage control method for multi-terminal AC/DC distribution system

    NASA Astrophysics Data System (ADS)

    Ma, Zhoujun; Zhu, Hong; Zhou, Dahong; Wang, Chunning; Tang, Renquan; Xu, Honghua

    2017-08-01

    A hierarchical control system is proposed in this paper to control the voltage of multi-terminal AC/DC distribution system. The hierarchical control system consists of PCC voltage control system, DG voltage control system and voltage regulator control system. The functions of three systems are to control the voltage of DC distribution network, AC bus voltage and area voltage. A method is proposed to deal with the whole control system. And a case study indicates that when voltage fluctuating, three layers of power flow control system is running orderly, and can maintain voltage stability.

  7. Optimizing Blocking and Nonblocking Reduction Operations for Multicore Systems: Hierarchical Design and Implementation

    SciTech Connect

    Gorentla Venkata, Manjunath; Shamis, Pavel; Graham, Richard L; Ladd, Joshua S; Sampath, Rahul S

    2013-01-01

    Many scientific simulations, using the Message Passing Interface (MPI) programming model, are sensitive to the performance and scalability of reduction collective operations such as MPI Allreduce and MPI Reduce. These operations are the most widely used abstractions to perform mathematical operations over all processes that are part of the simulation. In this work, we propose a hierarchical design to implement the reduction operations on multicore systems. This design aims to improve the efficiency of reductions by 1) tailoring the algorithms and customizing the implementations for various communication mechanisms in the system 2) providing the ability to configure the depth of hierarchy to match the system architecture, and 3) providing the ability to independently progress each of this hierarchy. Using this design, we implement MPI Allreduce and MPI Reduce operations (and its nonblocking variants MPI Iallreduce and MPI Ireduce) for all message sizes, and evaluate on multiple architectures including InfiniBand and Cray XT5. We leverage and enhance our existing infrastructure, Cheetah, which is a framework for implementing hierarchical collective operations to implement these reductions. The experimental results show that the Cheetah reduction operations outperform the production-grade MPI implementations such as Open MPI default, Cray MPI, and MVAPICH2, demonstrating its efficiency, flexibility and portability. On Infini- Band systems, with a microbenchmark, a 512-process Cheetah nonblocking Allreduce and Reduce achieves a speedup of 23x and 10x, respectively, compared to the default Open MPI reductions. The blocking variants of the reduction operations also show similar performance benefits. A 512-process nonblocking Cheetah Allreduce achieves a speedup of 3x, compared to the default MVAPICH2 Allreduce implementation. On a Cray XT5 system, a 6144-process Cheetah Allreduce outperforms the Cray MPI by 145%. The evaluation with an application kernel, Conjugate

  8. Hierarchical approaches for systems modeling in cardiac development.

    PubMed

    Gould, Russell A; Aboulmouna, Lina M; Varner, Jeffrey D; Butcher, Jonathan T

    2013-01-01

    Ordered cardiac morphogenesis and function are essential for all vertebrate life. The heart begins as a simple contractile tube, but quickly grows and morphs into a multichambered pumping organ complete with valves, while maintaining regulation of blood flow and nutrient distribution. Though not identical, cardiac morphogenesis shares many molecular and morphological processes across vertebrate species. Quantitative data across multiple time and length scales have been gathered through decades of reductionist single variable analyses. These range from detailed molecular signaling pathways at the cellular levels to cardiac function at the tissue/organ levels. However, none of these components act in true isolation from others, and each, in turn, exhibits short- and long-range effects in both time and space. With the absence of a gene, entire signaling cascades and genetic profiles may be shifted, resulting in complex feedback mechanisms. Also taking into account local microenvironmental changes throughout development, it is apparent that a systems level approach is an essential resource to accelerate information generation concerning the functional relationships across multiple length scales (molecular data vs physiological function) and structural development. In this review, we discuss relevant in vivo and in vitro experimental approaches, compare different computational frameworks for systems modeling, and the latest information about systems modeling of cardiac development. Finally, we conclude with some important future directions for cardiac systems modeling.

  9. Kepler's Multiple Planet Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2012-01-01

    Among the 1800 Kepler targets that have candidate planets, 20% have two or more candidate planets. While most of these objects have not yet been confirmed as true planets, several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Virtually all candidate systems are stable, as tested by numerical integrations (assuming a nominal mass-radius relationship). Statistical studies performed on these candidates reveal a great deal about the architecture of planetary systems, including the typical spacing of orbits and flatness of planetary systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. The characteristics of the confirmed Kepler multi-planet systems will also be discussed.

  10. Hierarchical Generalized Linear Models for Multiple Groups of Rare and Common Variants: Jointly Estimating Group and Individual-Variant Effects

    PubMed Central

    Yi, Nengjun; Liu, Nianjun; Zhi, Degui; Li, Jun

    2011-01-01

    Complex diseases and traits are likely influenced by many common and rare genetic variants and environmental factors. Detecting disease susceptibility variants is a challenging task, especially when their frequencies are low and/or their effects are small or moderate. We propose here a comprehensive hierarchical generalized linear model framework for simultaneously analyzing multiple groups of rare and common variants and relevant covariates. The proposed hierarchical generalized linear models introduce a group effect and a genetic score (i.e., a linear combination of main-effect predictors for genetic variants) for each group of variants, and jointly they estimate the group effects and the weights of the genetic scores. This framework includes various previous methods as special cases, and it can effectively deal with both risk and protective variants in a group and can simultaneously estimate the cumulative contribution of multiple variants and their relative importance. Our computational strategy is based on extending the standard procedure for fitting generalized linear models in the statistical software R to the proposed hierarchical models, leading to the development of stable and flexible tools. The methods are illustrated with sequence data in gene ANGPTL4 from the Dallas Heart Study. The performance of the proposed procedures is further assessed via simulation studies. The methods are implemented in a freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). PMID:22144906

  11. Incorporating Usability Criteria into the Development of Animated Hierarchical Maps

    ERIC Educational Resources Information Center

    Shih, Yu-Cheng; Huang, Pei-Ren; Chen, Sherry Y.

    2013-01-01

    Nowadays, Web-based learning systems have become popular because they can provide multiple tools, among which hierarchical maps are widely used to support teaching and learning. However, traditional hierarchical maps may let learners easily get lost within large information space. This study proposes an animated hierarchical map to address this…

  12. Incorporating Usability Criteria into the Development of Animated Hierarchical Maps

    ERIC Educational Resources Information Center

    Shih, Yu-Cheng; Huang, Pei-Ren; Chen, Sherry Y.

    2013-01-01

    Nowadays, Web-based learning systems have become popular because they can provide multiple tools, among which hierarchical maps are widely used to support teaching and learning. However, traditional hierarchical maps may let learners easily get lost within large information space. This study proposes an animated hierarchical map to address this…

  13. Hierarchical Self-Assembly of Peptide Amphiphiles: Form and Function at Multiple Length Scales

    NASA Astrophysics Data System (ADS)

    Zha, Runye Helen

    Hierarchical self-assembly, the organization of molecules into supramolecular structures of increasing size and complexity, is a potent tool for materials synthesis and requires understanding the connections of structure across multiple length scales. Herein, self-assembly of peptide amphiphiles (PAs) into nanoscopic and macroscopic materials is explored, and their anti-cancer applications are investigated. First, nanoscale assembly is examined in the context of an anti-angiogenic PA bearing the G-helix motif of maspin, a tumor suppressor protein. Assembly of this maspin-mimetic PA (MMPA) stabilizes the native G-helix conformation and improves binding to endothelial cells. Furthermore, PA nanostructures significantly increase cell adhesion to fibronectin as compared to G-helix peptide alone. Combined with its inhibitory effect on cell migration, MMPA nanostructures thus show anti-angiogenic activity on par with maspin protein in vitro and in vivo. Second, assembly of cationic PAs with hyaluronic acid (HA), an anionic polyelectrolyte, into macroscopic membranes is explored using PAs with identical formal charge but systematically varied self-assembly domains. Results suggest that membrane formation is dictated by the initial moments of component aggregation and is highly sensitive to PA molecular structure via nanoscale assembly. Specifically, PAs with beta-sheet forming residues are nanofibrous and have high surface charge density, leading to robust membranes with aligned-fiber microstructure. PAs without beta-sheet forming residues are nanospherical and have low surface charge density, leading to weak membranes with non-fibrous finger-like microstructure. Lastly, the principles of PA-HA membrane assembly are applied towards development of anti-cancer therapeutic biomaterials. Here, cytotoxic PAs bearing the epitope (KLAKLAKbeta)2 are co-assembled with non-bioactive cationic PA in order to achieve varying nanoscale morphology. These nanostructures are then

  14. The Case for A Hierarchal System Model for Linux Clusters

    SciTech Connect

    Seager, M; Gorda, B

    2009-06-05

    The computer industry today is no longer driven, as it was in the 40s, 50s and 60s, by High-performance computing requirements. Rather, HPC systems, especially Leadership class systems, sit on top of a pyramid investment mode. Figure 1 shows a representative pyramid investment model for systems hardware. At the base of the pyramid is the huge investment (order 10s of Billions of US Dollars per year) in semiconductor fabrication and process technologies. These costs, which are approximately doubling with every generation, are funded from investments multiple markets: enterprise, desktops, games, embedded and specialized devices. Over and above these base technology investments are investments for critical technology elements such as microprocessor, chipsets and memory ASIC components. Investments for these components are spread across the same markets as the base semiconductor processes investments. These second tier investments are approximately half the size of the lower level of the pyramid. The next technology investment layer up, tier 3, is more focused on scalable computing systems such as those needed for HPC and other markets. These tier 3 technology elements include networking (SAN, WAN and LAN), interconnects and large scalable SMP designs. Above these is tier 4 are relatively small investments necessary to build very large, scalable systems high-end or Leadership class systems. Primary among these are the specialized network designs of vertically integrated systems, etc.

  15. Multiple system atrophy

    MedlinePlus

    ... nervous system that controls important functions such as heart rate, blood pressure, and sweating. ... A pacemaker that is programmed to stimulate the heart to beat at ... blood pressure for some people. Constipation can be treated with ...

  16. Hierarchical Architectural Considerations in Econometric Modeling of Manufacturing Systems

    DTIC Science & Technology

    1981-06-01

    the model (e.g. center level as a function of cell level, etc.). Although the current effort was to develop an IDEF o activ- ity model, the...concepts and thoughts on synthesizing existing knowledge toward the objective of developing a hierarchical IDEF o econo- metric model for a large scale...review of the termin- ology and structure of IDEF o (ICAM definition method-version 0) is given in the subsequent paragraphs. Structured analysis

  17. Hierarchical flight control system synthesis for rotorcraft-based unmanned aerial vehicles

    NASA Astrophysics Data System (ADS)

    Shim, Hyunchul

    The Berkeley Unmanned Aerial Vehicle (UAV) research aims to design, implement, and analyze a group of autonomous intelligent UAVs and UGVs (Unmanned Ground Vehicles). The goal of this dissertation is to provide a comprehensive procedural methodology to design, implement, and test rotorcraft-based unmanned aerial vehicles (RUAVs). We choose the rotorcraft as the base platform for our aerial agents because it offers ideal maneuverability for our target scenarios such as the pursuit-evasion game. Aided by many enabling technologies such as lightweight and powerful computers, high-accuracy navigation sensors and communication devices, it is now possible to construct RUAVs capable of precise navigation and intelligent behavior by the decentralized onboard control system. Building a fully functioning RUAV requires a deep understanding of aeronautics, control theory and computer science as well as a tremendous effort for implementation. These two aspects are often inseparable and therefore equally highlighted throughout this research. The problem of multiple vehicle coordination is approached through the notion of a hierarchical system. The idea behind the proposed architecture is to build a hierarchical multiple-layer system that gradually decomposes the abstract mission objectives into the physical quantities of control input. Each RUAV incorporated into this system performs the given tasks and reports the results through the hierarchical communication channel back to the higher-level coordinator. In our research, we provide a theoretical and practical approach to build a number of RUAVs based on commercially available navigation sensors, computer systems, and radio-controlled helicopters. For the controller design, the dynamic model of the helicopter is first built. The helicopter exhibits a very complicated multi-input multi-output, nonlinear, time-varying and coupled dynamics, which is exposed to severe exogenous disturbances. This poses considerable difficulties for

  18. Bottom-up GGM algorithm for constructing multiple layered hierarchical gene regulatory networks

    USDA-ARS?s Scientific Manuscript database

    Multilayered hierarchical gene regulatory networks (ML-hGRNs) are very important for understanding genetics regulation of biological pathways. However, there are currently no computational algorithms available for directly building ML-hGRNs that regulate biological pathways. A bottom-up graphic Gaus...

  19. Covariates of the Rating Process in Hierarchical Models for Multiple Ratings of Test Items

    ERIC Educational Resources Information Center

    Mariano, Louis T.; Junker, Brian W.

    2007-01-01

    When constructed response test items are scored by more than one rater, the repeated ratings allow for the consideration of individual rater bias and variability in estimating student proficiency. Several hierarchical models based on item response theory have been introduced to model such effects. In this article, the authors demonstrate how these…

  20. Covariates of the Rating Process in Hierarchical Models for Multiple Ratings of Test Items

    ERIC Educational Resources Information Center

    Mariano, Louis T.; Junker, Brian W.

    2007-01-01

    When constructed response test items are scored by more than one rater, the repeated ratings allow for the consideration of individual rater bias and variability in estimating student proficiency. Several hierarchical models based on item response theory have been introduced to model such effects. In this article, the authors demonstrate how these…

  1. Hierarchical Multiple Regression in Counseling Research: Common Problems and Possible Remedies.

    ERIC Educational Resources Information Center

    Petrocelli, John V.

    2003-01-01

    A brief content analysis was conducted on the use of hierarchical regression in counseling research published in the "Journal of Counseling Psychology" and the "Journal of Counseling & Development" during the years 1997-2001. Common problems are cited and possible remedies are described. (Contains 43 references and 3 tables.) (Author)

  2. Complexity, Robustness, and Multistability in Network Systems with Switching Topologies: A Hierarchical Hybrid Control Approach

    DTIC Science & Technology

    2015-05-22

    AFRL-AFOSR-VA-TR-2015-0282 Complexity, Robustness, and Multistability in Network Systems with Switching Topologies A Hierarchical Hybrid Control ...concentrated on the development of a unified discontinuous dynamical framework for nonlinear network systems. In particular, control algorithms were... network systems, large-scale systems, adaptive control , discontinuous systems 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF

  3. Some physical applications of random hierarchical matrices

    SciTech Connect

    Avetisov, V. A.; Bikulov, A. Kh.; Vasilyev, O. A.; Nechaev, S. K.; Chertovich, A. V.

    2009-09-15

    The investigation of spectral properties of random block-hierarchical matrices as applied to dynamic and structural characteristics of complex hierarchical systems with disorder is proposed for the first time. Peculiarities of dynamics on random ultrametric energy landscapes are discussed and the statistical properties of scale-free and polyscale (depending on the topological characteristics under investigation) random hierarchical networks (graphs) obtained by multiple mapping are considered.

  4. A hierarchical approach to reliability modeling of fault-tolerant systems. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Gossman, W. E.

    1986-01-01

    A methodology for performing fault tolerant system reliability analysis is presented. The method decomposes a system into its subsystems, evaluates vent rates derived from the subsystem's conditional state probability vector and incorporates those results into a hierarchical Markov model of the system. This is done in a manner that addresses failure sequence dependence associated with the system's redundancy management strategy. The method is derived for application to a specific system definition. Results are presented that compare the hierarchical model's unreliability prediction to that of a more complicated tandard Markov model of the system. The results for the example given indicate that the hierarchical method predicts system unreliability to a desirable level of accuracy while achieving significant computational savings relative to component level Markov model of the system.

  5. Integrated control of active suspension system and electronic stability programme using hierarchical control strategy: theory and experiment

    NASA Astrophysics Data System (ADS)

    Xiao, Hansong; Chen, Wuwei; Zhou, HuiHui; Zu, Jean W.

    2011-02-01

    Integrated vehicle dynamics control has been an important research topic in the area of vehicle dynamics and control over the past two decades. The aim of integrated vehicle control is to improve the overall vehicle performance including handling, stability, and comfort through creating synergies in the use of sensor information, hardware, and control strategies. This paper proposes a two-layer hierarchical control architecture for integrated control of the active suspension system (ASS) and the electronic stability programme (ESP). The upper-layer controller is designed to coordinate the interactions between the ASS and the ESP. While in the lower layer, the two controllers including the ASS and the ESP are developed independently to achieve their local control objectives. Both a simulation investigation and a hardware-in-the-loop experimental study are performed. Simulation results demonstrate that the proposed hierarchical control system is able to improve the multiple vehicle performance indices including both the ride comfort and the lateral stability, compared with the non-integrated control system. Moreover, the experimental results verify the effectiveness of the design of the hierarchical control system.

  6. Risk transfer modeling among hierarchically associated stakeholders in development of space systems

    NASA Astrophysics Data System (ADS)

    Henkle, Thomas Grove, III

    reasonably exceed multiple tens of $millions per space project. Additional results indicate that current US government statutory arrangements on risk sharing with underwriting entities appears reasonable with respect to stated objectives. This research combines aspects of multiple disciplines to include risk management, decision theory, utility theory, and systems architecting. It also demonstrates development of a more general theory on prescribing risk transfer criteria between distinct, but hierarchically associated entities involved in complex system development with applicability to a variety of technical domains.

  7. EMIR: a configurable hierarchical system for event monitoring and incident response

    NASA Astrophysics Data System (ADS)

    Deich, William T. S.

    2014-07-01

    The Event Monitor and Incident Response system (emir) is a flexible, general-purpose system for monitoring and responding to all aspects of instrument, telescope, and general facility operations, and has been in use at the Automated Planet Finder telescope for two years. Responses to problems can include both passive actions (e.g. generating alerts) and active actions (e.g. modifying system settings). Emir includes a monitor-and-response daemon, plus graphical user interfaces and text-based clients that automatically configure themselves from data supplied at runtime by the daemon. The daemon is driven by a configuration file that describes each condition to be monitored, the actions to take when the condition is triggered, and how the conditions are aggregated into hierarchical groups of conditions. Emir has been implemented for the Keck Task Library (KTL) keyword-based systems used at Keck and Lick Observatories, but can be readily adapted to many event-driven architectures. This paper discusses the design and implementation of Emir , and the challenges in balancing the competing demands for simplicity, flexibility, power, and extensibility. Emir 's design lends itself well to multiple purposes, and in addition to its core monitor and response functions, it provides an effective framework for computing running statistics, aggregate values, and summary state values from the primitive state data generated by other subsystems, and even for creating quick-and-dirty control loops for simple systems.

  8. Hierarchical organization of a reference system in newborn spontaneous movements.

    PubMed

    Assmann, Birte; Romano, M Carmen; Thiel, Marco; Niemitz, Carsten

    2007-12-01

    In this paper, we studied spontaneous newborn movements regarding the coordination of the four limbs, arms and legs, from a dynamic perspective. We used the method of recurrence plots to analyse the kinematic data from audiovisual recordings of neonates. We identified temporal and spatial synchronization of the four limbs that resulted in high recurrence patterns of biomechanical reference configurations. Furthermore, we identified transitions between linear and nonlinear epochs in the movement behavior of newborns on different time scales by means of recurrence quantification analysis. Results are discussed in the context of the concept of a structural hierarchy, in which different time scales correspond to hierarchical levels of organization.

  9. Self-assembled hierarchically structured organic-inorganic composite systems.

    PubMed

    Tritschler, Ulrich; Cölfen, Helmut

    2016-05-13

    Designing bio-inspired, multifunctional organic-inorganic composite materials is one of the most popular current research objectives. Due to the high complexity of biocomposite structures found in nacre and bone, for example, a one-pot scalable and versatile synthesis approach addressing structural key features of biominerals and affording bio-inspired, multifunctional organic-inorganic composites with advanced physical properties is highly challenging. This article reviews recent progress in synthesizing organic-inorganic composite materials via various self-assembly techniques and in this context highlights a recently developed bio-inspired synthesis concept for the fabrication of hierarchically structured, organic-inorganic composite materials. This one-step self-organization concept based on simultaneous liquid crystal formation of anisotropic inorganic nanoparticles and a functional liquid crystalline polymer turned out to be simple, fast, scalable and versatile, leading to various (multi-)functional composite materials, which exhibit hierarchical structuring over several length scales. Consequently, this synthesis approach is relevant for further progress and scientific breakthrough in the research field of bio-inspired and biomimetic materials.

  10. Typical motions in multiple systems

    NASA Technical Reports Server (NTRS)

    Anosova, Joanna P.

    1990-01-01

    In very old times, people counted - one, two, many. The author wants to show that they were right. Consider the motions of isolated bodies: (1) N = 1 - simple motion; (2) N = 2 - Keplerian orbits; and (3) N = 3 - this is the difficult problem. In general, this problem can be studied only by computer simulations. The author studied this problem over many years (see, e.g., Agekian and Anosova, 1967; Anosova, 1986, 1989 a,b). The principal result is that two basic types of dynamics take place in triple systems. The first special type is the stable hierarchical systems with two almost Keplerian orbits. The second general type is the unstable triple systems with complicated motions of the bodies. By random choice of the initial conditions, by the Monte-Carlo method, the stable systems comprised about approx. 10% of the examined cases; the unstable systems comprised the other approx. 90% of cases under consideration. In N greater than 3, the studies of dynamics of such systems by computer simulations show that we have in general also the motions roughly as at the cases 1 - 3 with the relative negative or positive energies of the bodies. In the author's picture, the typical trajectories of the bodies in unstable triple systems of the general type of dynamics are seen. Such systems are disrupted always after close triple approaches of the bodies. These approaches play a role like the gravitational slingshot. Often, the velocities of escapers are very large. On the other hand, the movie also shows the dynamical processes of a formation, dynamical evolution and disruption of the temporary wide binaries in triples and a formation of final hard massive binaries in the final evolution of triples.

  11. MAD (Multi-Agent-Delivery) Nanolayer: Delivering Multiple Therapeutics from Hierarchical Assembled Surface Coatings

    PubMed Central

    Kim, Byeong-Su; Smith, Renée C.; Poon, Zhiyong; Hammond, Paula T.

    2014-01-01

    We present the hydrolytically degradable polymeric multilayer films that can co-deliver multiple therapeutics of differing chemical characteristics (charged biomacromolecules and neutral hydrophobic small molecules) from a surface. This multi-agent-delivery (MAD) nanolayer system integrates the hydrolytically degradable poly(β-amino ester) as a structural component to control the degradation of the multilayers to release active therapeutic macromolecules, as well as hydrophobic drugs imbedded within amphiphilic block copolymer micellar carriers within layer-by-layer (LbL) films, which would otherwise be difficult to include within the multilayers. By varying the anionic therapeutic agents (heparin and dextran sulfate) within the multilayer, we examine how different structural components can be used to control the release kinetics of multiple therapeutics from MAD nanolayers. Controlled release profiles and the in vitro efficacy of the MAD nanolayers in suppressing the growth of human smooth muscle cell lines were evaluated. The dual delivery of a charged macromolecular heparin and a small hydrophobic drug, paclitaxel, is found to be synergistic and beneficial toward effective therapeutic activity. Furthermore, we compared the classical dipping method we employed here with an automated spray-LbL technique. Spray-LbL significantly facilitates film processing time while preserving the characteristic release profiles of the MAD nanolayers. With the highly versatile and tunable nature of LbL assembly, we anticipate that MAD nanolayers can provide a unique platform for delivering multiple therapeutics from macromolecular to small molecules with distinct release profiles for applications in biological and biomedical surface coatings. PMID:19630389

  12. Design, fabrication and testing of hierarchical micro-optical structures and systems

    NASA Astrophysics Data System (ADS)

    Cannistra, Aaron Thomas

    Micro-optical systems are becoming essential components in imaging, sensing, communications, computing, and other applications. Optically based designs are replacing electronic, chemical and mechanical systems for a variety of reasons, including low power consumption, reduced maintenance, and faster operation. However, as the number and variety of applications increases, micro-optical system designs are becoming smaller, more integrated, and more complicated. Micro and nano-optical systems found in nature, such as the imaging systems found in many insects and crustaceans, can have highly integrated optical structures that vary in size by orders of magnitude. These systems incorporate components such as compound lenses, anti-reflective lens surface structuring, spectral filters, and polarization selective elements. For animals, these hybrid optical systems capable of many optical functions in a compact package have been repeatedly selected during the evolutionary process. Understanding the advantages of these designs gives motivation for synthetic optical systems with comparable functionality. However, alternative fabrication methods that deviate from conventional processes are needed to create such systems. Further complicating the issue, the resulting device geometry may not be readily compatible with existing measurement techniques. This dissertation explores several nontraditional fabrication techniques for optical components with hierarchical geometries and measurement techniques to evaluate performance of such components. A micro-transfer molding process is found to produce high-fidelity micro-optical structures and is used to fabricate a spectral filter on a curved surface. By using a custom measurement setup we demonstrate that the spectral filter retains functionality despite the nontraditional geometry. A compound lens is fabricated using similar fabrication techniques and the imaging performance is analyzed. A spray coating technique for photoresist

  13. Globular cluster formation with multiple stellar populations from hierarchical star cluster complexes

    NASA Astrophysics Data System (ADS)

    Bekki, Kenji

    2017-05-01

    Most old globular clusters (GCs) in the Galaxy are observed to have internal chemical abundance spreads in light elements. We discuss a new GC formation scenario based on hierarchical star formation within fractal molecular clouds. In the new scenario, a cluster of bound and unbound star clusters ('star cluster complex', SCC) that have a power-law cluster mass function with a slope (β) of 2 is first formed from a massive gas clump developed in a dwarf galaxy. Such cluster complexes and β = 2 are observed and expected from hierarchical star formation. The most massive star cluster ('main cluster'), which is the progenitor of a GC, can accrete gas ejected from asymptotic giant branch (AGB) stars initially in the cluster and other low-mass clusters before the clusters are tidally stripped or destroyed to become field stars in the dwarf. The SCC is initially embedded in a giant gas hole created by numerous supernovae of the SCC so that cold gas outside the hole can be accreted on to the main cluster later. New stars formed from the accreted gas have chemical abundances that are different from those of the original SCC. Using hydrodynamical simulations of GC formation based on this scenario, we show that the main cluster with the initial mass as large as [2-5] × 105 M⊙ can accrete more than 105 M⊙ gas from AGB stars of the SCC. We suggest that merging of hierarchical SSCs can play key roles in stellar halo formation around GCs and self-enrichment processes in the early phase of GC formation.

  14. Globular cluster formation with multiple stellar populations from hierarchical star cluster complexes

    NASA Astrophysics Data System (ADS)

    Bekki, Kenji

    2017-01-01

    Most old globular clusters (GCs) in the Galaxy are observed to have internal chemical abundance spreads in light elements. We discuss a new GC formation scenario based on hierarchical star formation within fractal molecular clouds. In the new scenario, a cluster of bound and unbound star clusters (`star cluster complex', SCC) that have a power-law cluster mass function with a slope (β) of 2 is first formed from a massive gas clump developed in a dwarf galaxy. Such cluster complexes and β = 2 are observed and expected from hierarchical star formation. The most massive star cluster (`main cluster'), which is the progenitor of a GC, can accrete gas ejected from asymptotic giant branch (AGB) stars initially in the cluster and other low-mass clusters before the clusters are tidally stripped or destroyed to become field stars in the dwarf. The SCC is initially embedded in a giant gas hole created by numerous supernovae of the SCC so that cold gas outside the hole can be accreted onto the main cluster later. New stars formed from the accreted gas have chemical abundances that are different from those of the original SCC. Using hydrodynamical simulations of GC formation based on this scenario, we show that the main cluster with the initial mass as large as [2 - 5] × 105M⊙ can accrete more than 105M⊙ gas from AGB stars of the SCC. We suggest that merging of hierarchical star cluster complexes can play key roles in stellar halo formation around GCs and self-enrichment processes in the early phase of GC formation.

  15. Violence against Chinese female sex workers from their stable partners: a hierarchical multiple regression analysis.

    PubMed

    Zhang, Chen; Li, Xiaoming; Su, Shaobing; Hong, Yan; Zhou, Yuejiao; Tang, Zhenzhu; Shen, Zhiyong

    2015-01-01

    Limited data are available regarding risk factors that are related to intimate partner violence (IPV) against female sex workers (FSWs) in the context of stable partnerships. Out of the 1,022 FSWs, 743 reported ever having a stable partnership and 430 (more than half) of those reported experiencing IPV. Hierarchical multivariate regression revealed that some characteristics of stable partners (e.g., low education, alcohol use) and relationship stressors (e.g., frequent friction, concurrent partnerships) were independently predictive of IPV against FSWs. Public health professionals who design future violence prevention interventions targeting FSWs need to consider the influence of their stable partners.

  16. Cellular Decomposition Based Hybrid-Hierarchical Control Systems with Applications to Flight Management Systems

    NASA Technical Reports Server (NTRS)

    Caines, P. E.

    1999-01-01

    The work in this research project has been focused on the construction of a hierarchical hybrid control theory which is applicable to flight management systems. The motivation and underlying philosophical position for this work has been that the scale, inherent complexity and the large number of agents (aircraft) involved in an air traffic system imply that a hierarchical modelling and control methodology is required for its management and real time control. In the current work the complex discrete or continuous state space of a system with a small number of agents is aggregated in such a way that discrete (finite state machine or supervisory automaton) controlled dynamics are abstracted from the system's behaviour. High level control may then be either directly applied at this abstracted level, or, if this is in itself of significant complexity, further layers of abstractions may be created to produce a system with an acceptable degree of complexity at each level. By the nature of this construction, high level commands are necessarily realizable at lower levels in the system.

  17. Synthesizing trait correlations and functional relationships across multiple scales: A Hierarchical Bayes approach

    NASA Astrophysics Data System (ADS)

    Shiklomanov, A. N.; Cowdery, E.; Dietze, M.

    2016-12-01

    Recent syntheses of global trait databases have revealed that although the functional diversity among plant species is immense, this diversity is constrained by trade-offs between plant strategies. However, the use of among-trait and trait-environment correlations at the global scale for both qualitative ecological inference and land surface modeling has several important caveats. An alternative approach is to preserve the existing PFT-based model structure while using statistical analyses to account for uncertainty and variability in model parameters. In this study, we used a hierarchical Bayesian model of foliar traits in the TRY database to test the following hypotheses: (1) Leveraging the covariance between foliar traits will significantly constrain our uncertainty in their distributions; and (2) Among-trait covariance patterns are significantly different among and within PFTs, reflecting differences in trade-offs associated with biome-level evolution, site-level community assembly, and individual-level ecophysiological acclimation. We found that among-trait covariance significantly constrained estimates of trait means, and the additional information provided by across-PFT covariance led to more constraint still, especially for traits and PFTs with low sample sizes. We also found that among-trait correlations were highly variable among PFTs, and were generally inconsistent with correlations within PFTs. The hierarchical multivariate framework developed in our study can readily be enhanced with additional levels of hierarchy to account for geographic, species, and individual-level variability.

  18. Emergence of hierarchical networks and polysynchronous behaviour in simple adaptive systems

    NASA Astrophysics Data System (ADS)

    Botella-Soler, V.; Glendinning, P.

    2012-03-01

    We describe the dynamics of a simple adaptive network. The network architecture evolves to a number of disconnected components on which the dynamics is characterized by the possibility of differently synchronized nodes within the same network (polysynchronous states). These systems may have implications for the evolutionary emergence of polysynchrony and hierarchical networks in physical or biological systems modeled by adaptive networks.

  19. Multi-scale Properties and Processes in Hierarchically-Structured Organic-Inorganic Solids and Surface-Based Microfluidic Systems

    NASA Astrophysics Data System (ADS)

    Messinger, Robert James

    Hierarchically-structured materials and surface-based microfluidic systems exhibit diverse properties that are inherently multi-scale in origin. In particular, different molecular, mesoscopic, and micron-scale properties and processes are often correlated and collectively account for many properties of interest, such as bulk catalytic activities or electrokinetic flow rates. However, such properties and processes often exhibit complex relationships over the different length scales that are not well understood, and consequently, difficult to control. Establishing correlations between them has been challenging, in part due to the difficulty of rigorously characterizing complex, heterogeneous materials and surface-based microfluidic experiments over multiple length scales, particularly at the molecular and mesoscopic levels. Herein, new multi-scale understanding and correlations have been established for different hierarchically-structured organic-inorganic solids or surface-based microfluidic systems, enabling control of material or device properties over discrete length scales. The molecular-level compositions, structures, interactions, and dynamics have been measured in diverse hierarchically-structured materials, such as mesostructured zeolites, mesostructured organosilicas, and organosiloxane foams, and subsequently correlated with their meso- and macroscopic material structures and properties. The results reveal new insights on the molecular-level interactions that govern their syntheses, the resulting local compositions and material structures, and the relationships among material properties over multiple characteristic length scales. Multi-dimensional solid-state nuclear magnetic resonance (NMR) spectroscopy is a cornerstone of these investigations, which enables correlative measurements in multiple frequency dimensions of the through-space or through-bond interactions between the constituent nuclei within the different materials. Other multi

  20. Multiple pass laser amplifier system

    DOEpatents

    Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

    1977-01-01

    A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

  1. Multiple bursitis in systemic sclerosis.

    PubMed

    Ishikawa, O; Akimoto, S; Sato, M; Miyachi, Y

    1997-06-01

    Bursitis is a common clinical entity usually induced by trauma and infection. It often occurs in inflammatory diseases such as gout and rheumatoid arthritis. We describe a patient with systemic sclerosis who developed multiple bursitis in the later stage of the disease.

  2. 1SWASP J093010.78+533859.5: A possible hierarchical quintuple system

    SciTech Connect

    Koo, Jae-Rim; Lee, Jae Woo; Lee, Byeong-Cheol; Kim, Seung-Lee; Lee, Chung-Uk; Hong, Kyeongsoo; Lee, Dong-Joo; Rey, Soo-Chang

    2014-05-01

    Among quadruples or higher multiplicity stars, only a few doubly eclipsing binary systems have been discovered. They are important targets for understanding the formation and evolution of multiple stellar systems because we can obtain accurate stellar parameters from photometric and spectroscopic studies. We present the observational results of this kind of rare object, 1SWASP J093010.78+533859.5, for which the doubly eclipsing feature had been detected previously from the SuperWASP photometric archive. Individual point-spread function photometry for two objects with a separation of about 1.''9 was performed for the first time in this study. Our time-series photometric data confirms the finding of Lohr et al. that the bright object A is an Algol-type detached eclipsing binary and the fainter B is a W UMa-type contact eclipsing. Using high-resolution optical spectra, we obtained well-defined radial velocity variations of system A. Furthermore, stationary spectral lines were detected that must have originated from a further, previously unrecognized stellar component. It was confirmed by the third object contribution from the light-curve analysis. No spectral feature of system B was detected, probably due to motion blur by long exposure times. We obtained the binary parameters and the absolute dimensions of systems A and B from light-curve synthesis with and without radial velocities, respectively. The primary and secondary components of system A have a spectral type of K1 and K5 main sequences, respectively. Two components of system B have nearly the same type of K3 main sequence. Light variations for both binaries are satisfactorily modeled by using two-spot models with one starspot on each component. We estimated the distances to systems A and B individually. Two systems may have similar distances of about 70 pc and seem to be gravitationally bound with a separation of about 130 AU. In conclusion, we suggest that 1SWASP J093010.78+533859.5 is a quintuple stellar

  3. Distributed Hierarchical Control of Multi-Area Power Systems with Improved Primary Frequency Regulation

    SciTech Connect

    Lian, Jianming; Marinovici, Laurentiu D.; Kalsi, Karanjit; Du, Pengwei; Elizondo, Marcelo A.

    2012-12-12

    The conventional distributed hierarchical control architecture for multi-area power systems is revisited. In this paper, a new distributed hierarchical control architecture is proposed. In the proposed architecture, pilot generators are selected in each area to be equipped with decentralized robust control as a supplementary to the conventional droop speed control. With the improved primary frequency control, the system frequency can be restored to the nominal value without the help of secondary frequency control, which reduces the burden of the automatic generation control for frequency restoration. Moreover, the low frequency inter-area electromechanical oscillations can also be effectively damped. The effectiveness of the proposed distributed hierarchical control architecture is validated through detailed simulations.

  4. HD 181068: a red giant in a triply eclipsing compact hierarchical triple system.

    PubMed

    Derekas, A; Kiss, L L; Borkovits, T; Huber, D; Lehmann, H; Southworth, J; Bedding, T R; Balam, D; Hartmann, M; Hrudkova, M; Ireland, M J; Kovács, J; Mezo, Gy; Moór, A; Niemczura, E; Sarty, G E; Szabó, Gy M; Szabó, R; Telting, J H; Tkachenko, A; Uytterhoeven, K; Benko, J M; Bryson, S T; Maestro, V; Simon, A E; Stello, D; Schaefer, G; Aerts, C; ten Brummelaar, T A; De Cat, P; McAlister, H A; Maceroni, C; Mérand, A; Still, M; Sturmann, J; Sturmann, L; Turner, N; Tuthill, P G; Christensen-Dalsgaard, J; Gilliland, R L; Kjeldsen, H; Quintana, E V; Tenenbaum, P; Twicken, J D

    2011-04-08

    Hierarchical triple systems comprise a close binary and a more distant component. They are important for testing theories of star formation and of stellar evolution in the presence of nearby companions. We obtained 218 days of Kepler photometry of HD 181068 (magnitude of 7.1), supplemented by ground-based spectroscopy and interferometry, which show it to be a hierarchical triple with two types of mutual eclipses. The primary is a red giant that is in a 45-day orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows evidence for tidally induced oscillations that are driven by the orbital motion of the close pair. HD 181068 is an ideal target for studies of dynamical evolution and testing tidal friction theories in hierarchical triple systems.

  5. Generating clustered journal maps: an automated system for hierarchical classification.

    PubMed

    Leydesdorff, Loet; Bornmann, Lutz; Wagner, Caroline S

    2017-01-01

    Journal maps and classifications for 11,359 journals listed in the combined Journal Citation Reports 2015 of the Science and Social Sciences Citation Indexes are provided at https://leydesdorff.github.io/journals/ and http://www.leydesdorff.net/jcr15. A routine using VOSviewer for integrating the journal mapping and their hierarchical clusterings is also made available. In this short communication, we provide background on the journal mapping/clustering and an explanation about and instructions for the routine. We compare journal maps for 2015 with those for 2014 and show the delineations among fields and subfields to be sensitive to fluctuations. Labels for fields and sub-fields are not provided by the routine, but an analyst can add them for pragmatic or intellectual reasons. The routine provides a means of testing one's assumptions against a baseline without claiming authority; clusters of related journals can be visualized to understand communities. The routine is generic and can be used for any 1-mode network.

  6. Multiple scales of patchiness and patch structure: a hierarchical framework for the study of heterogeneity

    USGS Publications Warehouse

    Kotliar, Natasha B.; Wiens, John A.

    1990-01-01

    We develop a hierarchical model of heterogeneity that provides a framework for classifying patch structure across a range of scales. Patches at lower levels in the hierarchy are more simplistic and correspond to the traditional view of patches. At levels approaching the upper bounds of the hierarchy the internal structure becomes more heterogeneous and boundaries more ambiguous. At each level in the hierarchy, patch structure will be influenced by both contrast among patches as well as the degree of aggregation of patches at lower levels in the hierarchy. We apply this model to foraging theory, but it has wider applications as in the study of habitat selection, population dynamics, and habitat fragmentation. It may also be useful in expanding the realm of landscape ecology beyond the current focus on anthropocentric scales.

  7. Multiple memory systems as substrates for multiple decision systems.

    PubMed

    Doll, Bradley B; Shohamy, Daphna; Daw, Nathaniel D

    2015-01-01

    It has recently become widely appreciated that value-based decision making is supported by multiple computational strategies. In particular, animal and human behavior in learning tasks appears to include habitual responses described by prominent model-free reinforcement learning (RL) theories, but also more deliberative or goal-directed actions that can be characterized by a different class of theories, model-based RL. The latter theories evaluate actions by using a representation of the contingencies of the task (as with a learned map of a spatial maze), called an "internal model." Given the evidence of behavioral and neural dissociations between these approaches, they are often characterized as dissociable learning systems, though they likely interact and share common mechanisms. In many respects, this division parallels a longstanding dissociation in cognitive neuroscience between multiple memory systems, describing, at the broadest level, separate systems for declarative and procedural learning. Procedural learning has notable parallels with model-free RL: both involve learning of habits and both are known to depend on parts of the striatum. Declarative memory, by contrast, supports memory for single events or episodes and depends on the hippocampus. The hippocampus is thought to support declarative memory by encoding temporal and spatial relations among stimuli and thus is often referred to as a relational memory system. Such relational encoding is likely to play an important role in learning an internal model, the representation that is central to model-based RL. Thus, insofar as the memory systems represent more general-purpose cognitive mechanisms that might subserve performance on many sorts of tasks including decision making, these parallels raise the question whether the multiple decision systems are served by multiple memory systems, such that one dissociation is grounded in the other. Here we investigated the relationship between model-based RL and

  8. A novel 3D constellation-masked method for physical security in hierarchical OFDMA system.

    PubMed

    Zhang, Lijia; Liu, Bo; Xin, Xiangjun; Liu, Deming

    2013-07-01

    This paper proposes a novel 3D constellation-masked method to ensure the physical security in hierarchical optical orthogonal frequency division multiplexing access (OFDMA) system. The 3D constellation masking is executed on the two levels of hierarchical modulation and among different OFDM subcarriers, which is realized by the masking vectors. The Lorenz chaotic model is adopted for the generation of masking vectors in the proposed scheme. A 9.85 Gb/s encrypted hierarchical QAM OFDM signal is successfully demonstrated in the experiment. The performance of illegal optical network unit (ONU) with different masking vectors is also investigated. The proposed method is demonstrated to be secure and efficient against the commonly known attacks in the experiment.

  9. A Hierarchical Target Extraction, Recognition, and Tracking (HiTert) system

    NASA Astrophysics Data System (ADS)

    Lu, Jun; Andrisani, Dominick, II; Tenorio, M. F.

    1992-03-01

    This research contributed to the development of a hierarchical target extraction, identification, and tracking system based on imaging sensors. The work suggests that passive tracking of ground targets is a desirable possibility. Our work involved computer rendering of a color image database containing 1000 images of a maneuvering tank; the use of image derived data to help track a violently maneuvering tank; the use of the Cantata Visual Programming Language to design the multiple interconnected algorithms in an intuitive and extensible manner; the delivery of this software to the U.S. Army Armament Research and Development Center (ARDEC) at Picatinny Arsenal, New Jersey; and presentation of a one day short course to engineers at ARDEC concerning the design and use of the software. This final report describes that software. Our research has suggested the need for the following future work: improved realism in the computer generated image database; development of additional higher level image processing and tracking modules using Cantata; and implementation of a way to communicate between competing algorithms.

  10. Estimating the Sizes of Populations At Risk of HIV Infection From Multiple Data Sources Using a Bayesian Hierarchical Model.

    PubMed

    Bao, Le; Raftery, Adrian E; Reddy, Amala

    2015-04-01

    In most countries in the world outside of sub-Saharan Africa, HIV is largely concentrated in sub-populations whose behavior puts them at higher risk of contracting and transmitting HIV, such as people who inject drugs, sex workers and men who have sex with men. Estimating the size of these sub-populations is important for assessing overall HIV prevalence and designing effective interventions. We present a Bayesian hierarchical model for estimating the sizes of local and national HIV key affected populations. The model incorporates multiple commonly used data sources including mapping data, surveys, interventions, capture-recapture data, estimates or guesstimates from organizations, and expert opinion. The proposed model is used to estimate the numbers of people who inject drugs in Bangladesh.

  11. Disturbance patterns in a socio-ecological system at multiple scales

    Treesearch

    G. Zurlini; Kurt H. Riitters; N. Zaccarelli; I. Petrosillo; K.B. Jones; L. Rossi

    2006-01-01

    Ecological systems with hierarchical organization and non-equilibrium dynamics require multiple-scale analyses to comprehend how a system is structured and to formulate hypotheses about regulatory mechanisms. Characteristic scales in real landscapes are determined by, or at least reflect, the spatial patterns and scales of constraining human interactions with the...

  12. Application of a hierarchical habitat unit classification system: stream habitat and salmonid distribution in Ward Creek, southeast Alaska.

    Treesearch

    M.D. Bryant; B.E. Wright; B.J. Davies

    1992-01-01

    A hierarchical classification system separating stream habitat into habitat units defined by stream morphology and hydrology was used in a pre-enhancement stream survey. The system separates habitat units into macrounits, mesounits, and micro- units and includes a separate evaluation of instream cover that also uses the hierarchical scheme. This paper presents an...

  13. Multiple-Primitives Hierarchical Classification of Airborne Laser Scanning Data in Urban Areas

    NASA Astrophysics Data System (ADS)

    Ni, H.; Lin, X. G.; Zhang, J. X.

    2017-09-01

    A hierarchical classification method for Airborne Laser Scanning (ALS) data of urban areas is proposed in this paper. This method is composed of three stages among which three types of primitives are utilized, i.e., smooth surface, rough surface, and individual point. In the first stage, the input ALS data is divided into smooth surfaces and rough surfaces by employing a step-wise point cloud segmentation method. In the second stage, classification based on smooth surfaces and rough surfaces is performed. Points in the smooth surfaces are first classified into ground and buildings based on semantic rules. Next, features of rough surfaces are extracted. Then, points in rough surfaces are classified into vegetation and vehicles based on the derived features and Random Forests (RF). In the third stage, point-based features are extracted for the ground points, and then, an individual point classification procedure is performed to classify the ground points into bare land, artificial ground and greenbelt. Moreover, the shortages of the existing studies are analyzed, and experiments show that the proposed method overcomes these shortages and handles more types of objects.

  14. MULTIPLE ECH LAUNCHER CONTROL SYSTEM

    SciTech Connect

    GREEN,M.T; PONCE,D; GRUNLOH,H.J; ELLIS,R.A; GROSNICKLE,W.H; HUMPHREY,R.L

    2003-10-01

    OAK-B135 The addition of new, high power gyrotrons to the heating and current drive arsenal at DIII-D, required a system upgrade for control of fully steerable ECH Launchers. Each launcher contains two pointing mirrors with two degrees of mechanical freedom. The two flavors of motion are called facet and tilt. Therefore up to four channels of motion per launcher need to be controlled. The system utilizes absolute encoders to indicate mirror position and therefore direction of the microwave beam. The launcher movement is primarily controlled by PLC, but future iterations of design, may require this control to be accomplished by a CPU on fast bus such as Compact PCI. This will be necessary to accomplish real time position control. Safety of equipment and personnel is of primary importance when controlling a system of moving parts. Therefore multiple interlocks and fault status enunciators have been implemented. This paper addresses the design of a Multiple ECH Launcher Control System, and characterizes the flexibility needed to upgrade to a real time position control system in the future.

  15. Priming Effects Associated with the Hierarchical Levels of Classification Systems

    ERIC Educational Resources Information Center

    Loehrlein, Aaron J.

    2012-01-01

    The act of categorization produces conceptual representations in memory while knowledge organization (KO) systems provide conceptual representations that are used in information storage and retrieval systems. Previous research has explored how KO systems can be designed to resemble the user's internal conceptual structures. However, the more…

  16. Priming Effects Associated with the Hierarchical Levels of Classification Systems

    ERIC Educational Resources Information Center

    Loehrlein, Aaron J.

    2012-01-01

    The act of categorization produces conceptual representations in memory while knowledge organization (KO) systems provide conceptual representations that are used in information storage and retrieval systems. Previous research has explored how KO systems can be designed to resemble the user's internal conceptual structures. However, the more…

  17. TOWARD HIGHLY SECURE AND AUTONOMIC COMPUTING SYSTEMS: A HIERARCHICAL APPROACH

    SciTech Connect

    Lee, Hsien-Hsin S

    2010-05-11

    The overall objective of this research project is to develop novel architectural techniques as well as system software to achieve a highly secure and intrusion-tolerant computing system. Such system will be autonomous, self-adapting, introspective, with self-healing capability under the circumstances of improper operations, abnormal workloads, and malicious attacks. The scope of this research includes: (1) System-wide, unified introspection techniques for autonomic systems, (2) Secure information-flow microarchitecture, (3) Memory-centric security architecture, (4) Authentication control and its implication to security, (5) Digital right management, (5) Microarchitectural denial-of-service attacks on shared resources. During the period of the project, we developed several architectural techniques and system software for achieving a robust, secure, and reliable computing system toward our goal.

  18. HIERARCHICAL METHODOLOGY FOR MODELING HYDROGEN STORAGE SYSTEMS. PART I: SCOPING MODELS

    SciTech Connect

    Hardy, B; Donald L. Anton, D

    2008-12-22

    Detailed models for hydrogen storage systems provide essential design information about flow and temperature distributions, as well as, the utilization of a hydrogen storage media. However, before constructing a detailed model it is necessary to know the geometry and length scales of the system, along with its heat transfer requirements, which depend on the limiting reaction kinetics. More fundamentally, before committing significant time and resources to the development of a detailed model, it is necessary to know whether a conceptual storage system design is viable. For this reason, a hierarchical system of models progressing from scoping models to detailed analyses was developed. This paper, which discusses the scoping models, is the first in a two part series that presents a collection of hierarchical models for the design and evaluation of hydrogen storage systems.

  19. Multiple testing on standardized mortality ratios: a Bayesian hierarchical model for FDR estimation.

    PubMed

    Ventrucci, Massimo; Scott, E Marian; Cocchi, Daniela

    2011-01-01

    The analysis of large data sets of standardized mortality ratios (SMRs), obtained by collecting observed and expected disease counts in a map of contiguous regions, is a first step in descriptive epidemiology to detect potential environmental risk factors. A common situation arises when counts are collected in small areas, that is, where the expected count is very low, and disease risks underlying the map are spatially correlated. Traditional p-value-based methods, which control the false discovery rate (FDR) by means of Poisson p-values, might achieve small sensitivity in identifying risk in small areas. This problem is the focus of the present work, where a Bayesian approach which performs a test to evaluate the null hypothesis of no risk over each SMR and controls the posterior FDR is proposed. A Bayesian hierarchical model including spatial random effects to allow for extra-Poisson variability is implemented providing estimates of the posterior probabilities that the null hypothesis of absence of risk is true. By means of such posterior probabilities, an estimate of the posterior FDR conditional on the data can be computed. A conservative estimation is needed to achieve the control which is checked by simulation. The availability of this estimate allows the practitioner to determine nonarbitrary FDR-based selection rules to identify high-risk areas according to a preset FDR level. Sensitivity and specificity of FDR-based rules are studied via simulation and a comparison with p-value-based rules is also shown. A real data set is analyzed using rules based on several FDR levels.

  20. Determining the Bayesian optimal sampling strategy in a hierarchical system.

    SciTech Connect

    Grace, Matthew D.; Ringland, James T.; Boggs, Paul T.; Pebay, Philippe Pierre

    2010-09-01

    Consider a classic hierarchy tree as a basic model of a 'system-of-systems' network, where each node represents a component system (which may itself consist of a set of sub-systems). For this general composite system, we present a technique for computing the optimal testing strategy, which is based on Bayesian decision analysis. In previous work, we developed a Bayesian approach for computing the distribution of the reliability of a system-of-systems structure that uses test data and prior information. This allows for the determination of both an estimate of the reliability and a quantification of confidence in the estimate. Improving the accuracy of the reliability estimate and increasing the corresponding confidence require the collection of additional data. However, testing all possible sub-systems may not be cost-effective, feasible, or even necessary to achieve an improvement in the reliability estimate. To address this sampling issue, we formulate a Bayesian methodology that systematically determines the optimal sampling strategy under specified constraints and costs that will maximally improve the reliability estimate of the composite system, e.g., by reducing the variance of the reliability distribution. This methodology involves calculating the 'Bayes risk of a decision rule' for each available sampling strategy, where risk quantifies the relative effect that each sampling strategy could have on the reliability estimate. A general numerical algorithm is developed and tested using an example multicomponent system. The results show that the procedure scales linearly with the number of components available for testing.

  1. Differential deviant probability effects on two hierarchical levels of the auditory novelty system.

    PubMed

    López-Caballero, Fran; Zarnowiec, Katarzyna; Escera, Carles

    2016-10-01

    Deviance detection is a key functional property of the auditory system that allows pre-attentive discrimination of incoming stimuli not conforming to a rule extracted from the ongoing constant stimulation, thereby proving that regularities in the auditory scene have been encoded in the auditory system. Using simple-feature stimulus deviations, regularity encoding and deviance detection have been reported in brain responses at multiple latencies of the human Auditory Evoked Potential (AEP), such as the Mismatch Negativity (MMN; peaking at 100-250ms from stimulus onset) and Middle-Latency Responses (MLR; peaking at 12-50ms). More complex levels of regularity violations, however, are only indexed by AEPs generated at higher stages of the auditory system, suggesting a hierarchical organization in the encoding of auditory regularities. The aim of the current study is to further characterize the auditory hierarchy of novelty responses, by assessing the sensitivity of MLR components to deviant probability manipulations. MMNs and MLRs were recorded in 24 healthy participants, using an oddball location paradigm with three different deviant probabilities (5%, 10% and 20%), and a reversed-standard (91.5%). We analyzed differences in the MLRs elicited to each of the deviant stimuli and the reversed-standard, as well as within deviant stimuli. Our results confirmed deviance detection at the level of both MLRs and MMN, but significant differences for deviant probabilities were found only for the MMN. These results suggest a functional dissociation between regularity encoding, already present at early stages of auditory processing, and the encoding of the probability with which this regularity is disrupted, which is only processed at higher stages of the auditory hierarchy.

  2. Binaries and Multiple Stellar Systems

    NASA Astrophysics Data System (ADS)

    Horch, Elliott

    Binary and multiple stellar systems have importance in three main areas of astronomy and astrophysics. First, because of the relatively simple gravitational interaction at work in the case of binary stars, these systems provide a basic check on stellar structure and evolution theory since the masses may be determined through observation. When these masses can be linked to other properties of the two stars, such as luminosity, color, and radius, they can provide very stringent constraints on stellar models. Second, the statistics of binary and multiple star systems provide clues to star formation mechanisms and environmental effects in the galactic gravitational potential and in clusters. Although a number of good results have been obtained in nearby star clusters and associations, knowledge of the field population has been somewhat limited until recently by a lack of large, complete samples of binaries. However, there appears to be a great deal of promise in this area for the coming decade in part due to astrometric satellites such as Hipparcos and Gaia. Third, the binary scenario is invoked to explain several important types of astrophysical phenomena such as Type Ia supernovae, cataclysmic variables, and stellar x-ray sources. Since the first of these mentioned is a standard candle for the extragalactic distance scale, it may even be said binary stars play a minor role in field of cosmology. However, in this chapter, the focus will mainly be on normal stars in binary and multiple-stellar systems. The basic physics of binaries will be reviewed, and the observational methods in use today will be discussed together with their limitations and prospects for the future. Finally, an overview of the current science in the three main areas mentioned where binaries have a significant impact will be given.

  3. Hierarchical models and iterative optimization of hybrid systems

    SciTech Connect

    Rasina, Irina V.; Baturina, Olga V.; Nasatueva, Soelma N.

    2016-06-08

    A class of hybrid control systems on the base of two-level discrete-continuous model is considered. The concept of this model was proposed and developed in preceding works as a concretization of the general multi-step system with related optimality conditions. A new iterative optimization procedure for such systems is developed on the base of localization of the global optimality conditions via contraction the control set.

  4. Automating Multiple Software Packages in Simulation Research for Structural Equation Modeling and Hierarchical Linear Modeling

    ERIC Educational Resources Information Center

    Gagne, Phill; Furlow, Carolyn F.

    2009-01-01

    Simulation researchers are sometimes faced with the need to use multiple statistical software packages in the process of conducting their research, potentially having to go between software packages manually. This can be a tedious and time-consuming process that generally motivates researchers to use fewer replications in their simulations than…

  5. Two-stage hierarchical group testing for multiple infections with application to the Infertility Prevention Project

    PubMed Central

    Tebbs, Joshua M.; McMahan, Christopher S.; Bilder, Christopher R.

    2015-01-01

    Summary Screening for sexually transmitted diseases has benefited greatly from the use of group testing (pooled testing) to lower costs. With the development of assays that detect multiple infections, screening practices now involve testing pools of individuals for multiple infections simultaneously. Building on the research for single infection group testing procedures, we examine the performance of group testing for multiple infections. Our work is motivated by chlamydia and gonorrhea testing for the Infertility Prevention Project (IPP), a national program in the United States. We consider a two-stage pooling algorithm currently used to perform testing for the IPP. We first derive the operating characteristics of this algorithm for classification purposes (e.g., expected number of tests, misclassification probabilities, etc.) and identify pool sizes that minimize the expected number of tests. We then develop an expectation-maximization algorithm to estimate probabilities of infection using both group and individual retest responses. Our research shows that group testing can offer large cost savings when classifying individuals for multiple infections and can provide prevalence estimates that are actually more efficient than those from individual testing. PMID:24117173

  6. Two-stage hierarchical group testing for multiple infections with application to the infertility prevention project.

    PubMed

    Tebbs, Joshua M; McMahan, Christopher S; Bilder, Christopher R

    2013-12-01

    Screening for sexually transmitted diseases (STDs) has benefited greatly from the use of group testing (pooled testing) to lower costs. With the development of assays that detect multiple infections, screening practices now involve testing pools of individuals for multiple infections simultaneously. Building on the research for single infection group testing procedures, we examine the performance of group testing for multiple infections. Our work is motivated by chlamydia and gonorrhea testing for the infertility prevention project (IPP), a national program in the United States. We consider a two-stage pooling algorithm currently used to perform testing for the IPP. We first derive the operating characteristics of this algorithm for classification purposes (e.g., expected number of tests, misclassification probabilities, etc.) and identify pool sizes that minimize the expected number of tests. We then develop an expectation-maximization (EM) algorithm to estimate probabilities of infection using both group and individual retest responses. Our research shows that group testing can offer large cost savings when classifying individuals for multiple infections and can provide prevalence estimates that are actually more efficient than those from individual testing. © 2013, The International Biometric Society.

  7. Set-point changes in hierarchically-arranged thermogenic systems

    NASA Technical Reports Server (NTRS)

    Horowitz, J. M.

    1984-01-01

    Rats acclimated to either 23 or 5 C were concurrently exposed to cold and hypergravic fields to test the proposal that mammals have parallel controllers for thermoregulation. The two groups of rats were used to evaluate the different relative contributions of shivering and nonshivering thermogenesis to the increased oxygen consumption of the cold-exposed rats in hypergravic fields. The lower magnitude of the cold-induced oxygen consumption observed when cold-exposed rats are moved from 1 G to hypergravic fields is probably due to an inactivation of shivering rather than nonshivering thermogenesis. The observation that shivering, but not nonshivering thermogenesis, appears to be impaired by hypergravic fields is consistent with the representation of central thermoregulation by multiple controllers.

  8. Hierarchical Liouville-space approach for accurate and universal characterization of quantum impurity systems.

    PubMed

    Li, ZhenHua; Tong, NingHua; Zheng, Xiao; Hou, Dong; Wei, JianHua; Hu, Jie; Yan, YiJing

    2012-12-28

    A hierarchical equations of motion based numerical approach is developed for accurate and efficient evaluation of dynamical observables of strongly correlated quantum impurity systems. This approach is capable of describing quantitatively Kondo resonance and Fermi-liquid characteristics, achieving the accuracy of the latest high-level numerical renormalization group approach, as demonstrated on single-impurity Anderson model systems. Its application to a two-impurity Anderson model results in differential conductance versus external bias, which correctly reproduces the continuous transition from Kondo states of individual impurity to singlet spin states formed between two impurities. The outstanding performance on characterizing both equilibrium and nonequilibrium properties of quantum impurity systems makes the hierarchical equations of motion approach potentially useful for addressing strongly correlated lattice systems in the framework of dynamical mean-field theory.

  9. Efficient Hierarchic Management for Reconfiguration of Networked Information Systems

    DTIC Science & Technology

    2004-01-01

    to acknowledge many helpful discus- sions about this work and about the Siena software system with Antonio Carzaniga , Alex Wolf, and Dennis Heimbig...Systems Review, Vol. 34 No. 5, pp 186- 2001, December 1999. [2] A. Carzaniga , D. Rosenblum, A. Wolf. “Design and Evalua- tion of a Wide-Area Event...Notification Service.” ACM Trans- actions on Computer Systems, Vol. 19, No. 3, pp. 332-383, August 2001. [3] A. Carzaniga , A. Wolf. “Content-based Networking

  10. Bayesian Non-Parametric Hierarchical Modeling for Multiple Membership Data in Grouped Attendance Interventions.

    PubMed

    Savitsky, Terrance D; Paddock, Susan M

    2013-06-01

    We develop a dependent Dirichlet process (DDP) model for repeated measures multiple membership (MM) data. This data structure arises in studies under which an intervention is delivered to each client through a sequence of elements which overlap with those of other clients on different occasions. Our interest concentrates on study designs for which the overlaps of sequences occur for clients who receive an intervention in a shared or grouped fashion whose memberships may change over multiple treatment events. Our motivating application focuses on evaluation of the effectiveness of a group therapy intervention with treatment delivered through a sequence of cognitive behavioral therapy session blocks, called modules. An open-enrollment protocol permits entry of clients at the beginning of any new module in a manner that may produce unique MM sequences across clients. We begin with a model that composes an addition of client and multiple membership module random effect terms, which are assumed independent. Our MM DDP model relaxes the assumption of conditionally independent client and module random effects by specifying a collection of random distributions for the client effect parameters that are indexed by the unique set of module attendances. We demonstrate how this construction facilitates examining heterogeneity in the relative effectiveness of group therapy modules over repeated measurement occasions.

  11. Hierarchical system for autonomous sensing-healing of delamination in large-scale composite structures

    NASA Astrophysics Data System (ADS)

    Minakuchi, Shu; Sun, Denghao; Takeda, Nobuo

    2014-10-01

    This study combines our hierarchical fiber-optic-based delamination detection system with a microvascular self-healing material to develop the first autonomous sensing-healing system applicable to large-scale composite structures. In this combined system, embedded vascular modules are connected through check valves to a surface-mounted supply tube of a pressurized healing agent while fiber-optic-based sensors monitor the internal pressure of these vascular modules. When delamination occurs, the healing agent flows into the vascular modules breached by the delamination and infiltrates the damage for healing. At the same time, the pressure sensors identify the damaged modules by detecting internal pressure changes. This paper begins by describing the basic concept of the combined system and by discussing the advantages that arise from its hierarchical nature. The feasibility of the system is then confirmed through delamination infiltration tests. Finally, the hierarchical system is validated in a plate specimen by focusing on the detection and infiltration of the damage. Its self-diagnostic function is also demonstrated.

  12. Performance Modeling of Network-Attached Storage Device Based Hierarchical Mass Storage Systems

    NASA Technical Reports Server (NTRS)

    Menasce, Daniel A.; Pentakalos, Odysseas I.

    1995-01-01

    Network attached storage devices improve I/O performance by separating control and data paths and eliminating host intervention during the data transfer phase. Devices are attached to both a high speed network for data transfer and to a slower network for control messages. Hierarchical mass storage systems use disks to cache the most recently used files and a combination of robotic and manually mounted tapes to store the bulk of the files in the file system. This paper shows how queuing network models can be used to assess the performance of hierarchical mass storage systems that use network attached storage devices as opposed to host attached storage devices. Simulation was used to validate the model. The analytic model presented here can be used, among other things, to evaluate the protocols involved in 1/0 over network attached devices.

  13. Multiple channel data acquisition system

    DOEpatents

    Crawley, H. Bert; Rosenberg, Eli I.; Meyer, W. Thomas; Gorbics, Mark S.; Thomas, William D.; McKay, Roy L.; Homer, Jr., John F.

    1990-05-22

    A multiple channel data acquisition system for the transfer of large amounts of data from a multiplicity of data channels has a plurality of modules which operate in parallel to convert analog signals to digital data and transfer that data to a communications host via a FASTBUS. Each module has a plurality of submodules which include a front end buffer (FEB) connected to input circuitry having an analog to digital converter with cache memory for each of a plurality of channels. The submodules are interfaced with the FASTBUS via a FASTBUS coupler which controls a module bus and a module memory. The system is triggered to effect rapid parallel data samplings which are stored to the cache memories. The cache memories are uploaded to the FEBs during which zero suppression occurs. The data in the FEBs is reformatted and compressed by a local processor during transfer to the module memory. The FASTBUS coupler is used by the communications host to upload the compressed and formatted data from the module memory. The local processor executes programs which are downloaded to the module memory through the FASTBUS coupler.

  14. Multiple channel data acquisition system

    DOEpatents

    Crawley, H.B.; Rosenberg, E.I.; Meyer, W.T.; Gorbics, M.S.; Thomas, W.D.; McKay, R.L.; Homer, J.F. Jr.

    1990-05-22

    A multiple channel data acquisition system for the transfer of large amounts of data from a multiplicity of data channels has a plurality of modules which operate in parallel to convert analog signals to digital data and transfer that data to a communications host via a FASTBUS. Each module has a plurality of submodules which include a front end buffer (FEB) connected to input circuitry having an analog to digital converter with cache memory for each of a plurality of channels. The submodules are interfaced with the FASTBUS via a FASTBUS coupler which controls a module bus and a module memory. The system is triggered to effect rapid parallel data samplings which are stored to the cache memories. The cache memories are uploaded to the FEBs during which zero suppression occurs. The data in the FEBs is reformatted and compressed by a local processor during transfer to the module memory. The FASTBUS coupler is used by the communications host to upload the compressed and formatted data from the module memory. The local processor executes programs which are downloaded to the module memory through the FASTBUS coupler. 25 figs.

  15. Hierarchical spin-orbital polarization of a giant Rashba system.

    PubMed

    Bawden, Lewis; Riley, Jonathan M; Kim, Choong H; Sankar, Raman; Monkman, Eric J; Shai, Daniel E; Wei, Haofei I; Lochocki, Edward B; Wells, Justin W; Meevasana, Worawat; Kim, Timur K; Hoesch, Moritz; Ohtsubo, Yoshiyuki; Le Fèvre, Patrick; Fennie, Craig J; Shen, Kyle M; Chou, Fangcheng; King, Phil D C

    2015-09-01

    The Rashba effect is one of the most striking manifestations of spin-orbit coupling in solids and provides a cornerstone for the burgeoning field of semiconductor spintronics. It is typically assumed to manifest as a momentum-dependent splitting of a single initially spin-degenerate band into two branches with opposite spin polarization. Combining polarization-dependent and resonant angle-resolved photoemission measurements with density functional theory calculations, we show that the two "spin-split" branches of the model giant Rashba system BiTeI additionally develop disparate orbital textures, each of which is coupled to a distinct spin configuration. This necessitates a reinterpretation of spin splitting in Rashba-like systems and opens new possibilities for controlling spin polarization through the orbital sector.

  16. Hierarchical spin-orbital polarization of a giant Rashba system

    PubMed Central

    Bawden, Lewis; Riley, Jonathan M.; Kim, Choong H.; Sankar, Raman; Monkman, Eric J.; Shai, Daniel E.; Wei, Haofei I.; Lochocki, Edward B.; Wells, Justin W.; Meevasana, Worawat; Kim, Timur K.; Hoesch, Moritz; Ohtsubo, Yoshiyuki; Le Fèvre, Patrick; Fennie, Craig J.; Shen, Kyle M.; Chou, Fangcheng; King, Phil D. C.

    2015-01-01

    The Rashba effect is one of the most striking manifestations of spin-orbit coupling in solids and provides a cornerstone for the burgeoning field of semiconductor spintronics. It is typically assumed to manifest as a momentum-dependent splitting of a single initially spin-degenerate band into two branches with opposite spin polarization. Combining polarization-dependent and resonant angle-resolved photoemission measurements with density functional theory calculations, we show that the two “spin-split” branches of the model giant Rashba system BiTeI additionally develop disparate orbital textures, each of which is coupled to a distinct spin configuration. This necessitates a reinterpretation of spin splitting in Rashba-like systems and opens new possibilities for controlling spin polarization through the orbital sector. PMID:26601268

  17. INTERFEROMETRIC OBSERVATIONS OF THE HIERARCHICAL TRIPLE SYSTEM ALGOL

    SciTech Connect

    Csizmadia, Sz.; Borkovits, T.; Paragi, Zs.; Abraham, P.; Szabados, L.; Mosoni, L.; Sturmann, L.; Sturmann, J.; Farrington, C.; McAlister, H. A.; Brummelaar, T. A. ten; Turner, N. H.; Klagyivik, P.

    2009-11-01

    Algol is a triple stellar system consisting of a close semidetached binary orbited by a third object. Due to the disputed spatial orientation of the close pair, the third body perturbation of this pair is a subject of much research. In this study, we determine the spatial orientation of the close pair orbital plane using the CHARA Array, a six-element optical/IR interferometer located on Mount Wilson, and state-of-the-art e-EVN interferometric techniques. We find that the longitude of the line of nodes for the close pair is OMEGA{sub 1} = 48 deg. +- 2 deg. and the mutual inclination of the orbital planes of the close and the wide pairs is 95 deg. +- 3 deg. This latter value differs by 5{sup 0} from the formerly known 100 deg., which would imply a very fast inclination variation of the system, not borne out by the photometric observations. We also investigated the dynamics of the system with numerical integration of the equations of motions using our result as an initial condition. We found large variations in the inclination of the close pair (its amplitude approx170{sup 0}) with a period of about 20 millennia. This result is in good agreement with the photometrically observed change of amplitude in Algol's primary minimum.

  18. Hierarchical Organization of Frontotemporal Networks for the Prediction of Stimuli across Multiple Dimensions

    PubMed Central

    Blenkmann, Alejandro; Hughes, Laura E.; Bekinschtein, Tristan A.; Rowe, James B.

    2015-01-01

    Brain function can be conceived as a hierarchy of generative models that optimizes predictions of sensory inputs and minimizes “surprise.” Each level of the hierarchy makes predictions of neural events at a lower level in the hierarchy, which returns a prediction error when these expectations are violated. We tested the generalization of this hypothesis to multiple sequential deviations, and we identified the most likely organization of the network that accommodates deviations in temporal structure of stimuli. Magnetoencephalography of healthy human participants during an auditory paradigm identified prediction error responses in bilateral primary auditory cortex, superior temporal gyrus, and lateral prefrontal cortex for deviation by frequency, intensity, location, duration, and silent gap. We examined the connectivity between cortical sources using a set of 21 generative models that embedded alternate hypotheses of frontotemporal network dynamics. Bayesian model selection provided evidence for two new features of functional network organization. First, an expectancy signal provided input to the prefrontal cortex bilaterally, related to the temporal structure of stimuli. Second, there are functionally significant lateral connections between superior temporal and/or prefrontal cortex. The results support a predictive coding hypothesis but go beyond previous work in demonstrating the generalization to multiple concurrent stimulus dimensions and the evidence for a temporal expectancy input at the higher level of the frontotemporal hierarchy. We propose that this framework for studying the brain's response to unexpected events is not limited to simple sensory tasks but may also apply to the neurocognitive mechanisms of higher cognitive functions and their disorders. PMID:26109651

  19. Power and resistance within the hospital's hierarchical system: the experiences of chronically ill patients.

    PubMed

    Griscti, Odette; Aston, Megan; Warner, Grace; Martin-Misener, Ruth; McLeod, Deborah

    2017-01-01

    To explore experiences of chronically ill patients and registered nurses when they negotiate patient care in hospital settings. Specifically, we explored how social and institutional discourses shape power relations during the negotiation process. The hospital system is embedded in a hierarchical structure where the voice of the healthcare provider as expert is often given more importance than the patient. This system has been criticised as being oppressive to patients who are perceived to be lower in the hierarchy. In this study, we illustrate how the hospital's hierarchical system is not always oppressing but can also create moments of empowerment for patients. A feminist poststructuralist approach informed by the teaching of Foucault was used to explore power relations between nurses and patients when negotiating patient care in hospital settings. Eight individuals who suffered from chronic illness shared their stories about how they negotiated their care with nurses in hospital settings. The interviews were tape-recorded. Discourse analysis was used to analyse the data. Patients recounted various experiences when their voices were not heard because the current hospital system privileged the healthcare provider experts' advice over the patients' voice. The hierarchical structure of hospital supported these dynamics by privileging nurses as gatekeepers of service, by excluding the patients' input in the nursing notes and through a process of self-regulation. However, patients in this study were not passive recipients of care and used their agency creatively to resist these discourses. Nurses need to be mindful of how the hospital's hierarchical system tends to place nurses in a position of power, and how their authoritative position may positively or adversely affect the negotiation of patient care. © 2016 John Wiley & Sons Ltd.

  20. Design and placement of multimedia objects in hypermedia applications on hierarchical storage systems

    NASA Astrophysics Data System (ADS)

    Tikekar, Rahul V.; Fotouhi, Farshad A.; Ragan, Don P.

    1999-08-01

    Hypermedia applications use multimedia objects that are linked to each other via some application logic. Also, hypermedia applications can potentially become very storage intensive because of the nature of data in them. Hierarchical storage systems are an excellent way to store large hypermedia applications. In this paper we look, at the problem of placing multimedia objects in a hierarchical storage system so that their retrieval meets the needs of the application while at the same time keeping storage intensive data on cheaper storage. We use an abstract hierarchy approach along with an enhancement of the relationship management methodology to prose a framework for the design of hypermedia applications. The abstract hierarchy consists of a hierarchy of abstracts growing in size and linked together. The intrinsic nature of the abstract hierarchy makes it possible to map it easily to both the hierarchical storage system and the hypermedia application paradigm. In this framework, the designer can determine where each abstract of the application can be placed on the storage system.

  1. Hierarchical Organization of Frontotemporal Networks for the Prediction of Stimuli across Multiple Dimensions.

    PubMed

    Phillips, Holly N; Blenkmann, Alejandro; Hughes, Laura E; Bekinschtein, Tristan A; Rowe, James B

    2015-06-24

    Brain function can be conceived as a hierarchy of generative models that optimizes predictions of sensory inputs and minimizes "surprise." Each level of the hierarchy makes predictions of neural events at a lower level in the hierarchy, which returns a prediction error when these expectations are violated. We tested the generalization of this hypothesis to multiple sequential deviations, and we identified the most likely organization of the network that accommodates deviations in temporal structure of stimuli. Magnetoencephalography of healthy human participants during an auditory paradigm identified prediction error responses in bilateral primary auditory cortex, superior temporal gyrus, and lateral prefrontal cortex for deviation by frequency, intensity, location, duration, and silent gap. We examined the connectivity between cortical sources using a set of 21 generative models that embedded alternate hypotheses of frontotemporal network dynamics. Bayesian model selection provided evidence for two new features of functional network organization. First, an expectancy signal provided input to the prefrontal cortex bilaterally, related to the temporal structure of stimuli. Second, there are functionally significant lateral connections between superior temporal and/or prefrontal cortex. The results support a predictive coding hypothesis but go beyond previous work in demonstrating the generalization to multiple concurrent stimulus dimensions and the evidence for a temporal expectancy input at the higher level of the frontotemporal hierarchy. We propose that this framework for studying the brain's response to unexpected events is not limited to simple sensory tasks but may also apply to the neurocognitive mechanisms of higher cognitive functions and their disorders. Copyright © 2015 Phillips et al.

  2. Hierarchical Medical System Based on Big Data and Mobile Internet: A New Strategic Choice in Health Care.

    PubMed

    Wang, Yaogang; Sun, Li; Hou, Jie

    2017-08-08

    China is setting up a hierarchical medical system to solve the problems of biased resource allocation and high patient flows to large hospitals. The development of big data and mobile Internet technology provides a new perspective for the establishment of hierarchical medical system. This viewpoint discusses the challenges with the hierarchical medical system in China and how big data and mobile Internet can be used to mitigate these challenges. ©Yaogang Wang, Li Sun, Jie Hou. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 08.08.2017.

  3. The Design and Implementation of a Hierarchical Interface for the Multi-Lingual Database System.

    DTIC Science & Technology

    1985-06-01

    Multi-backend Database System (MBDS), Hierarchical Data Model, Data Language I (DL/I) Attribute=ba~ed Data Language ( ABDL ), Language Interface...attribute- based data language ( ABDL ) requests. We describe the software engineering aspects of our implementation and an overview of the four modules which...52 2. Database Manipulations................. 54 * a. The DL/I GET Calls to the ABDL RETRIRVE............. 5 b. The DL/I GET HOLD Calls to the

  4. Hierarchical Bio-Inspired Cooperative Control for Nonlinear Dynamical Systems and Hardware Demonstration

    DTIC Science & Technology

    2013-04-03

    AFRL-RV- PS - AFRL-RV- PS - TR-2012-0248 TR-2012-0248 HIERARCHICAL BIO-INSPIRED COOPERATIVE CONTROL FOR NONLINEAR DYNAMICAL SYSTEMS AND HARDWARE...Center (DTIC) (http://www.dtic.mil). AFRL-RV- PS -TR-2012-0248 HAS BEEN REVIEWED AND IS APPROVED FOR PUBLICATION IN ACCORDANCE WITH ASSIGNED...REPORT Kirtland AFB, NM 87117-5776 NUMBER(S) AFRL-RV- PS -TR-2012-0248 12. DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release

  5. Disintegrating Multiple Systems in Early Stellar Evolution

    NASA Astrophysics Data System (ADS)

    Reipurth, Bo

    2000-12-01

    near-infrared object. For typical parameters, this geometry persists for only 5000 yr or so. If the ejected star does not escape, cyclic motion of a hierarchical triple begins. This explains the so-called IRC binaries that are infrequently found in star-forming regions. The standard model of early stellar evolution states that young stars gradually and smoothly make the transitions from Class 0 through Class I and II objects to eventually become Class III objects. In contrast, stars born in multiple systems can abruptly transit from a Class 0 or I object to a visible T Tauri star. The main accretion phase may be terminated by the stochastic process of triple decay. Depending on the moment of triple disintegration, the ejected objects can range from stellar embryos, which will emerge as very low mass stars or even brown dwarfs, to essentially fully built-up stars. In this picture, the initial mass function toward its low-mass end has an important stochastic component that can only be described by the half-life of the decay processes. Because the ejected stars can take only limited circumstellar material with them, they will soon lose their classical T Tauri characteristics and join the halo of weak-line T Tauri stars that surround star-forming clouds. Differences in ejection may explain why two apparently similar T Tauri stars of about the same age can have major differences in the size of their circumstellar disks.

  6. Hierarchical Bayesian regularization of reconstructions for diffuse optical tomography using multiple priors

    PubMed Central

    Abdelnour, Farras; Genovese, Christopher; Huppert, Theodore

    2010-01-01

    Diffuse optical tomography (DOT) is a non-invasive brain imaging technique that uses low-levels of near-infrared light to measure optical absorption changes due to regional blood flow and blood oxygen saturation in the brain. By arranging light sources and detectors in a grid over the surface of the scalp, DOT studies attempt to spatially localize changes in oxy- and deoxy-hemoglobin in the brain that result from evoked brain activity during functional experiments. However, the reconstruction of accurate spatial images of hemoglobin changes from DOT data is an ill-posed linearized inverse problem, which requires model regularization to yield appropriate solutions. In this work, we describe and demonstrate the application of a parametric restricted maximum likelihood method (ReML) to incorporate multiple statistical priors into the recovery of optical images. This work is based on similar methods that have been applied to the inverse problem for magnetoencephalography (MEG). Herein, we discuss the adaptation of this model to DOT and demonstrate that this approach provides a means to objectively incorporate reconstruction constraints and demonstrate this approach through a series of simulated numerical examples. PMID:21258532

  7. Assessing Short-Term Voltage Stability of Electric Power Systems by a Hierarchical Intelligent System.

    PubMed

    Xu, Yan; Zhang, Rui; Zhao, Junhua; Dong, Zhao Yang; Wang, Dianhui; Yang, Hongming; Wong, Kit Po

    2016-08-01

    In the smart grid paradigm, growing integration of large-scale intermittent renewable energies has introduced significant uncertainties to the operations of an electric power system. This makes real-time dynamic security assessment (DSA) a necessity to enable enhanced situational-awareness against the risk of blackouts. Conventional DSA methods are mainly based on the time-domain simulation, which are insufficiently fast and knowledge-poor. In recent years, the intelligent system (IS) strategy has been identified as a promising approach to facilitate real-time DSA. While previous works mainly concentrate on the rotor angle stability, this paper focuses on another yet increasingly important dynamic insecurity phenomenon-the short-term voltage instability, which involves fast and complex load dynamics. The problem is modeled as a classification subproblem for transient voltage collapse and a prediction subproblem for unacceptable dynamic voltage deviation. A hierarchical IS is developed to address the two subproblems sequentially. The IS is based on ensemble learning of random-weights neural networks and is implemented in an offline training, a real-time application, and an online updating pattern. The simulation results on the New England 39-bus system verify its superiority in both learning speed and accuracy over some state-of-the-art learning algorithms.

  8. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    PubMed

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  9. A Hierarchical Bayesian Model for Reconstructing Multiple Streamflows and Climate Indices from Tree-ring or other paleo data

    NASA Astrophysics Data System (ADS)

    Lall, U.; Zamora, M. R.; Cook, E.; Gelman, A.; Sperry, E.

    2003-12-01

    Reconstruction of annual or seasonal streamflow at multiple locations or of multiple climatic indices (e.g., PDSI at many locations, or ENSO, PDO, NAO) is sometimes of interest using an array of common paleo predictors. The predictands may be correlated with each other, and the form of each regression between predictand and predictors may also be very similar. Principal or Canonical Component Methods have been used to address this regression problem, after transformation of the data sets to be approximately Normally distributed. An alternative to such methods is presented here. A hierarchical model considers that the regression coefficients are random variables, and seeks to make inferences about the parameters (e.g., they may be Normally distributed, with a certain vector of means and a covariance matrix) of a model that describes the distribution of these variables. Further, the parameters of such a model may in turn be considered to be random variables and one can seek a model that describes them, leading to a multilevel modeling approach. Generally, a diffuse prior distribution is assumed for the parameters at the end of the hierarchy, and a Markov Chain Monte Carlo approach is used to learn or estimate the parameters of the distribution at each level of the hierarchy. Here, we use such an approach in a Generalized Linear Modeling framework - the distribution of the predictand is directly considered to correspond to a parametric family, instead of using transformations to Normality, and a set of basis functions (not necessarily linear) is used to relate the predictors to the predictands. An uncertainty distribution of parameters and hence of estimates is derived automatically as part of the model learning process. We present examples of the applications of these methods and contrast the results with those obtained using PCA/CCA.

  10. Temporal Hierarchical Adaptive Texture CRF for Automatic Detection of Gadolinium-Enhancing Multiple Sclerosis Lesions in Brain MRI.

    PubMed

    Karimaghaloo, Zahra; Rivaz, Hassan; Arnold, Douglas L; Collins, D Louis; Arbel, Tal

    2015-06-01

    We propose a conditional random field (CRF) based classifier for segmentation of small enhanced pathologies. Specifically, we develop a temporal hierarchical adaptive texture CRF (THAT-CRF) and apply it to the challenging problem of gad enhancing lesion segmentation in brain MRI of patients with multiple sclerosis. In this context, the presence of many nonlesion enhancements (such as blood vessels) renders the problem more difficult. In addition to voxel-wise features, the framework exploits multiple higher order textures to discriminate the true lesional enhancements from the pool of other enhancements. Since lesional enhancements show more variation over time as compared to the nonlesional ones, we incorporate temporal texture analysis in order to study the textures of enhanced candidates over time. The parameters of the THAT-CRF model are learned based on 2380 scans from a multi-center clinical trial. The effect of different components of the model is extensively evaluated on 120 scans from a separate multi-center clinical trial. The incorporation of the temporal textures results in a general decrease of the false discovery rate. Specifically, THAT-CRF achieves overall sensitivity of 95% along with false discovery rate of 20% and average false positive count of 0.5 lesions per scan. The sensitivity of the temporal method to the trained time interval is further investigated on five different intervals of 69 patients. Moreover, superior performance is achieved by the reviewed labelings of our model compared to the fully manual labeling when applied to the context of separating different treatment arms in a real clinical trial.

  11. A hierarchical competing systems model of the emergence and early development of executive function

    PubMed Central

    Marcovitch, Stuart; Zelazo, Philip David

    2010-01-01

    The hierarchical competing systems model (HCSM) provides a framework for understanding the emergence and early development of executive function – the cognitive processes underlying the conscious control of behavior – in the context of search for hidden objects. According to this model, behavior is determined by the joint influence of a developmentally invariant habit system and a conscious representational system that becomes increasingly influential as children develop. This article describes a computational formalization of the HCSM, reviews behavioral and computational research consistent with the model, and suggests directions for future research on the development of executive function. PMID:19120405

  12. Hierarchical graphs for better annotations of rule-based models of biochemical systems

    SciTech Connect

    Hu, Bin; Hlavacek, William

    2009-01-01

    In the graph-based formalism of the BioNetGen language (BNGL), graphs are used to represent molecules, with a colored vertex representing a component of a molecule, a vertex label representing the internal state of a component, and an edge representing a bond between components. Components of a molecule share the same color. Furthermore, graph-rewriting rules are used to represent molecular interactions, with a rule that specifies addition (removal) of an edge representing a class of association (dissociation) reactions and with a rule that specifies a change of vertex label representing a class of reactions that affect the internal state of a molecular component. A set of rules comprises a mathematical/computational model that can be used to determine, through various means, the system-level dynamics of molecular interactions in a biochemical system. Here, for purposes of model annotation, we propose an extension of BNGL that involves the use of hierarchical graphs to represent (1) relationships among components and subcomponents of molecules and (2) relationships among classes of reactions defined by rules. We illustrate how hierarchical graphs can be used to naturally document the structural organization of the functional components and subcomponents of two proteins: the protein tyrosine kinase Lck and the T cell receptor (TCR)/CD3 complex. Likewise, we illustrate how hierarchical graphs can be used to document the similarity of two related rules for kinase-catalyzed phosphorylation of a protein substrate. We also demonstrate how a hierarchical graph representing a protein can be encoded in an XML-based format.

  13. Inventory and Billing Systems for Multiple Users.

    ERIC Educational Resources Information Center

    Frazier, Lavon

    1985-01-01

    Washington State University developed a comprehensive supplies inventory system and a generalized billing system with multiple users in mind. The inventory management system and the service center billing system are described. (Author/MLW)

  14. Inventory and Billing Systems for Multiple Users.

    ERIC Educational Resources Information Center

    Frazier, Lavon

    1985-01-01

    Washington State University developed a comprehensive supplies inventory system and a generalized billing system with multiple users in mind. The inventory management system and the service center billing system are described. (Author/MLW)

  15. Models of Multiple System Atrophy

    PubMed Central

    Fellner, Lisa; Wenning, Gregor K.; Stefanova, Nadia

    2016-01-01

    Multiple system atrophy (MSA) is a predominantly sporadic, adult-onset, fatal neurodegenerative disease of unknown etiology. MSA is characterized by autonomic failure, levodopa-unresponsive parkinsonism, cerebellar ataxia and pyramidal signs in any combination. MSA belongs to a group of neurodegenerative disorders termed α-synucleinopathies, which also include Parkinson’s disease and dementia with Lewy bodies. Their common pathological feature is the occurrence of abnormal α-synuclein positive inclusions in neurons or glial cells. In MSA, the main cell type presenting aggregates composed of α-synuclein are oligodendroglial cells. This pathological hallmark, also called glial cytoplasmic inclusions (GCIs), is associated with progressive and profound neuronal loss in various regions of the brain. The development of animal models of MSA is justified by the limited understanding of the mechanisms of neurodegeneration and GCIs formation, which is paralleled by a lack of therapeutic strategies. Two main types of rodent models have been generated to replicate different features of MSA neuropathology. On one hand, neurotoxin-based models have been produced to reproduce neuronal loss in substantia nigra pars compacta and striatum. On the other hand, transgenic mouse models with overexpression of α-synuclein in oligodendroglia have been used to reproduce GCIs-related pathology. This chapter gives an overview of the atypical Parkinson’s syndrome MSA and summarizes the currently available MSA animal models and their relevance for pre-clinical testing of disease-modifying therapies. PMID:24338664

  16. A top-down, hierarchical, system-of-systems approach to the design of an air-defense weapon

    NASA Astrophysics Data System (ADS)

    Ender, Tommer Rafael

    Systems engineering introduces the notion of top-down design, which involves viewing an entire system comprised of its components as a whole functioning unit. This requires an understanding of how those components efficiently interact, with optimization of the process emphasized rather than solely focusing on micro-level system components. The traditional approach to the systems engineering process involves requirements decomposition and flow down across a hierarchy of decision making levels, in which needs and requirements at one level are transformed into a set of system product and process descriptions for the next lower level. This top-down requirements flow approach therefore requires an iterative process between adjacent levels to verify that the design solution satisfies the requirements, with no direct flow between nonadjacent hierarchy levels. This thesis will introduce a methodology that enables decision makers anywhere across a system-of-systems hierarchy to rapidly and simultaneously manipulate the design space, however complex. A hierarchical decision making process will be developed in which multiple operationally and managerially independent systems interact to affect a series of top level metrics. This takes the notion of top-down requirements flow one step further to allow for simultaneous bottom-up and top-down design, enabled by the use of neural network surrogate models to represent the complex design space. Using a proof-of-concept case study of employing a guided projectile for mortar interception, this process will show how the iterative steps that are usually required when dealing with flowing requirements from one level to the next lower in the systems engineering process are eliminated, allowing for direct manipulation across nonadjacent levels in the hierarchy. For this system-of-systems environment comprised of a Monte Carlo based design space exploration employing rapid surrogate models, both bottom-up and top-down design analysis may

  17. A debugging system for azimuthally acoustic logging tools based on modular and hierarchical design ideas

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Ju, X. D.; Lu, J. Q.; Men, B. Y.

    2016-08-01

    On the basis of modular and hierarchical design ideas, this study presents a debugging system for an azimuthally sensitive acoustic bond tool (AABT). The debugging system includes three parts: a personal computer (PC), embedded front-end machine and function expansion boards. Modular and hierarchical design ideas are conducted in all design and debug processes. The PC communicates with the front-end machine via the Internet, and the front-end machine and function expansion boards connect each other by the extended parallel bus. In this method, the three parts of the debugging system form stable and high-speed data communication. This study not only introduces the system-level debugging and sub-system level debugging of the tool but also the debugging of the analogue signal processing board, which is important and greatly used in logging tools. Experiments illustrate that the debugging system can greatly improve AABT verification and calibration efficiency and that, board-level debugging can examine and improve analogue signal processing boards. The design thinking is clear and the design structure is reasonable, thus making it easy to extend and upgrade the debugging system.

  18. Hierarchical analytical and simulation modelling of human-machine systems with interference

    NASA Astrophysics Data System (ADS)

    Braginsky, M. Ya; Tarakanov, D. V.; Tsapko, S. G.; Tsapko, I. V.; Baglaeva, E. A.

    2017-01-01

    The article considers the principles of building the analytical and simulation model of the human operator and the industrial control system hardware and software. E-networks as the extension of Petri nets are used as the mathematical apparatus. This approach allows simulating complex parallel distributed processes in human-machine systems. The structural and hierarchical approach is used as the building method for the mathematical model of the human operator. The upper level of the human operator is represented by the logical dynamic model of decision making based on E-networks. The lower level reflects psychophysiological characteristics of the human-operator.

  19. Risk Assessment for Mobile Systems Through a Multilayered Hierarchical Bayesian Network.

    PubMed

    Li, Shancang; Tryfonas, Theo; Russell, Gordon; Andriotis, Panagiotis

    2016-08-01

    Mobile systems are facing a number of application vulnerabilities that can be combined together and utilized to penetrate systems with devastating impact. When assessing the overall security of a mobile system, it is important to assess the security risks posed by each mobile applications (apps), thus gaining a stronger understanding of any vulnerabilities present. This paper aims at developing a three-layer framework that assesses the potential risks which apps introduce within the Android mobile systems. A Bayesian risk graphical model is proposed to evaluate risk propagation in a layered risk architecture. By integrating static analysis, dynamic analysis, and behavior analysis in a hierarchical framework, the risks and their propagation through each layer are well modeled by the Bayesian risk graph, which can quantitatively analyze risks faced to both apps and mobile systems. The proposed hierarchical Bayesian risk graph model offers a novel way to investigate the security risks in mobile environment and enables users and administrators to evaluate the potential risks. This strategy allows to strengthen both app security as well as the security of the entire system.

  20. Delay-dependent H∞ robust control for large power systems based on two-level hierarchical decentralised coordinated control structure

    NASA Astrophysics Data System (ADS)

    Dou, Chun-Xia; Duan, Zhi-Sheng; Jia, Xing-Bei

    2013-02-01

    This article focuses on a novel two-level hierarchical decentralised coordinated control which consists of several local fuzzy power system stabilisers (LFPSSs) for each generator at the first level tuned by supervisory power system stabiliser (SPSS) at the secondary level for the transient stabilisation improvement of large power systems. First, in order to compensate the inherent nonlinear interconnections between subsystems in system dynamic model, a direct feedback linearisation compensator is proposed to act through the local excitation machine. Afterwards, the T-S fuzzy model-based decentralised LFPSS for each generator is designed. Then, for the purpose of improving dynamic performance, the SPSS is designed by using the remote signals from the wide area measurements system. However, there are unavoidable delays involved before the remote signals are received at the SPSS site or the control signals of SPSS are sent to the local systems. Taking consideration of the multiple delays, by using less conservative delay-dependent Lyapunov approach, the authors develop a delay-dependent H∞ robust control technique based on the decentralised coordinated control structure. Some sufficient conditions for the system stabilisation are presented in terms of linear matrix inequalities dependent only on the upper bounds of the time delays. Finally, the effectiveness of the proposed control scheme is demonstrated through simulation examples.

  1. Obliquities of Kepler stars: comparison of single- and multiple-transit systems

    SciTech Connect

    Morton, Timothy D.; Winn, Joshua N.

    2014-11-20

    The stellar obliquity of a transiting planetary system can be constrained by combining measurements of the star's rotation period, radius, and projected rotational velocity. Here, we present a hierarchical Bayesian technique for recovering the obliquity distribution of a population of transiting planetary systems and apply it to a sample of 70 Kepler objects of interest. With ≈95% confidence, we find that the obliquities of stars with only a single detected transiting planet are systematically larger than those with multiple detected transiting planets. This suggests that a substantial fraction of Kepler's single-transiting systems represent dynamically hotter, less orderly systems than the 'pancake-flat' multiple-transiting systems.

  2. The stability of tidal equilibrium for hierarchical star-planet-moon systems

    NASA Astrophysics Data System (ADS)

    Adams, Fred C.; Bloch, Anthony M.

    2016-11-01

    Motivated by the current search for exomoons, this paper considers the stability of tidal equilibrium for hierarchical three-body systems containing a star, a planet, and a moon. In this treatment, the energy and angular momentum budgets include contributions from the planetary orbit, lunar orbit, stellar spin, planetary spin, and lunar spin. The goal is to determine the optimized energy state of the system subject to the constraint of constant angular momentum. Because of the lack of a closed form solution for the full three-body problem, however, we must use an approximate description of the orbits. We first consider the Keplerian limit and find that the critical energy states are saddle points, rather than minima, so that these hierarchical systems have no stable tidal equilibrium states. We then generalize the calculation so that the lunar orbit is described by a time-averaged version of the circular restricted three-body problem. In this latter case, the critical energy state is a shallow minimum, so that a tidal equilibrium state exists. In both cases, however, the lunar orbit for the critical point lies outside the boundary (roughly half the Hill radius) where (previous) numerical simulations indicate dynamical instability. These results suggest that star-planet-moon systems have no viable long-term stable states analogous to those found for two-body systems.

  3. Hierarchical rapid modeling and simulation of high-performance picture archive and communications systems

    NASA Astrophysics Data System (ADS)

    Anderson, Kenneth R.; Meredith, Glenn; Prior, Fred W.; Wirsz, Emil; Wilson, Dennis L.

    1992-07-01

    Due to the expense and time required to configure and evaluate large scale PACS rapid modeling and simulation of system configurations is critical. The results of the analysis can be used to drive the design of both hardware and software. System designers can use the models to help them during the actual system integration. This paper will show how the LANNET 11. 5 and NE1''WORK 11. 5 modeling tools can be used hierarchically to model and simulate large PACS. The detailed description of the Communication Network model which is one of three models used for the Medical Diagnostic Imaging Support System (MDIS) design analysis will be presented. The paper will conclude with future issues in the modeling of MDIS and other large heterogeneous networks of computers and workstations. The way that the models might be used throughout the system life cycle to reduce the operation and maintenance costs of the system is explained.

  4. Multiple Hospital Systems and the Teaching Hospital.

    ERIC Educational Resources Information Center

    Levitan, Mark S.

    1979-01-01

    Although a substantial portion of hospital beds are in institutions that are in multiple hospital systems, the possible benefits to be gained through participation in such systems do not appear to be of sufficient magnitude to either core teaching hospitals or their parent universities to persuade them to join or form a multiple system.…

  5. Kepler Systems That Show Multiple Transiting Objects

    NASA Astrophysics Data System (ADS)

    Steffen, Jason H.; Fabrycky, D. C.; Ford, E. B.; Holman, M. J.; Lissauer, J. J.; Ragozzine, D.; Welsh, W. F.; Kepler Science Team

    2011-01-01

    Exoplanetary systems that have multiple transiting planets provide unique and important insight into the formation, evolution, and dynamics of exoplanetary systems. Kepler has announced the discovery of a confirmed planetary system with multiple transiting planets (Kepler 9, Holman et al. 2010) as well as several candidate planetary systems that show multiple transiting objects (Steffen et al. 2010). Kepler 9 shows deviations from a constant period due to the ongoing dynamical interactions between the confirmed planets. From these transit timing variations (TTV) one can measure the planetary masses from the photometric data alone. The presence of several systems with multiple transiting candidates from the first quarter of data indicate that Kepler should continue to find systems with multiple transiting planets. Such systems will provide important, general information about the histories of planetary systems.

  6. Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator

    NASA Astrophysics Data System (ADS)

    Pan, Xueping; Ju, Ping; Wu, Feng; Jin, Yuqing

    2017-09-01

    A new hierarchical parameter estimation method for doubly fed induction generator (DFIG) and drive train system in a wind turbine generator (WTG) is proposed in this paper. Firstly, the parameters of the DFIG and the drive train are estimated locally under different types of disturbances. Secondly, a coordination estimation method is further applied to identify the parameters of the DFIG and the drive train simultaneously with the purpose of attaining the global optimal estimation results. The main benefit of the proposed scheme is the improved estimation accuracy. Estimation results confirm the applicability of the proposed estimation technique.

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

    PubMed Central

    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

  8. HIERARCHICAL METHODOLOGY FOR MODELING HYDROGEN STORAGE SYSTEMS PART II: DETAILED MODELS

    SciTech Connect

    Hardy, B; Donald L. Anton, D

    2008-12-22

    There is significant interest in hydrogen storage systems that employ a media which either adsorbs, absorbs or reacts with hydrogen in a nearly reversible manner. In any media based storage system the rate of hydrogen uptake and the system capacity is governed by a number of complex, coupled physical processes. To design and evaluate such storage systems, a comprehensive methodology was developed, consisting of a hierarchical sequence of models that range from scoping calculations to numerical models that couple reaction kinetics with heat and mass transfer for both the hydrogen charging and discharging phases. The scoping models were presented in Part I [1] of this two part series of papers. This paper describes a detailed numerical model that integrates the phenomena occurring when hydrogen is charged and discharged. A specific application of the methodology is made to a system using NaAlH{sub 4} as the storage media.

  9. Use of a Hierarchical Oligonucleotide Primer Extension Approach for Multiplexed Relative Abundance Analysis of Methanogens in Anaerobic Digestion Systems

    PubMed Central

    Chuang, Hui-Ping; Hsu, Mao-Hsuan; Chen, Wei-Yu

    2013-01-01

    In this study, we established a rapid multiplex method to detect the relative abundances of amplified 16S rRNA genes from known cultivatable methanogens at hierarchical specificities in anaerobic digestion systems treating industrial wastewater and sewage sludge. The method was based on the hierarchical oligonucleotide primer extension (HOPE) technique and combined with a set of 27 primers designed to target the total archaeal populations and methanogens from 22 genera within 4 taxonomic orders. After optimization for their specificities and detection sensitivity under the conditions of multiple single-nucleotide primer extension reactions, the HOPE approach was applied to analyze the methanogens in 19 consortium samples from 7 anaerobic treatment systems (i.e., 513 reactions). Among the samples, the methanogen populations detected with order-level primers accounted for >77.2% of the PCR-amplified 16S rRNA genes detected using an Archaea-specific primer. The archaeal communities typically consisted of 2 to 7 known methanogen genera within the Methanobacteriales, Methanomicrobiales, and Methanosarcinales and displayed population dynamic and spatial distributions in anaerobic reactor operations. Principal component analysis of the HOPE data further showed that the methanogen communities could be clustered into 3 distinctive groups, in accordance with the distribution of the Methanosaeta, Methanolinea, and Methanomethylovorans, respectively. This finding suggested that in addition to acetotrophic and hydrogenotrophic methanogens, the methylotrophic methanogens might play a key role in the anaerobic treatment of industrial wastewater. Overall, the results demonstrated that the HOPE approach is a specific, rapid, and multiplexing platform to determine the relative abundances of targeted methanogens in PCR-amplified 16S rRNA gene products. PMID:24077716

  10. A proof-of-concept implementation of persistence in a hierarchical storage system

    SciTech Connect

    Grossman, R.; Qin, Xiao; Lifka, D.

    1992-12-31

    The concept of providing transparent access to a collection of files in a mass storage system is a familiar one. The goal of this project was to investigate the feasibility of providing similar access to a collection of persistent, complex objects. We describe an architecture for interfacing a persistent store of complex objects to a hierarchical storage system. Persistent object stores support the uniform creation, storage, and access of complex objects, regardless of their lifetimes. In other words, a mechanism is provided so that persistent objects outlive the processes which create them and can be accessed in a uniform manner by other processes. We validated this architecture by implementing a proof-of-concept system and testing the system on two stores of data. These tests indicate that this architecture supports the creation. storage and access of very large persistent object stores.

  11. A proof-of-concept implementation of persistence in a hierarchical storage system

    SciTech Connect

    Grossman, R.; Qin, Xiao . Lab. for Advanced Computing); Lifka, D. . High Energy Physics Div.)

    1992-01-01

    The concept of providing transparent access to a collection of files in a mass storage system is a familiar one. The goal of this project was to investigate the feasibility of providing similar access to a collection of persistent, complex objects. We describe an architecture for interfacing a persistent store of complex objects to a hierarchical storage system. Persistent object stores support the uniform creation, storage, and access of complex objects, regardless of their lifetimes. In other words, a mechanism is provided so that persistent objects outlive the processes which create them and can be accessed in a uniform manner by other processes. We validated this architecture by implementing a proof-of-concept system and testing the system on two stores of data. These tests indicate that this architecture supports the creation. storage and access of very large persistent object stores.

  12. A proof-of-concept implementation of persistence in a hierarchical storage system

    NASA Technical Reports Server (NTRS)

    Grossman, Robert; Qin, Xiao; Lifka, Dave

    1992-01-01

    The concept of providing transparent access to a collection of files in a mass storage system is a familiar one. The goal of this project was to investigate the feasibility of providing similar access to a collection of persistent, complex objects. We describe an architecture for interfacing a persistent store of complex objects to a hierarchical storage system. Persistent object stores support the uniform creation, storage, and access of complex objects, regardless of their lifetimes. In other words, a mechanism is provided so that persistent objects outlive the processes which create them and can be accessed in a uniform manner by other processes. We validated this architecture by implementing a proof-of-concept system and testing the system on two stores of data. These tests indicate that this architecture supports the creation, storage, and access of very large persistent object stores.

  13. Hierarchical Ada robot programming system (HARPS)- A complete and working telerobot control system based on the NASREM model

    NASA Technical Reports Server (NTRS)

    Leake, Stephen; Green, Tom; Cofer, Sue; Sauerwein, Tim

    1989-01-01

    HARPS is a telerobot control system that can perform some simple but useful tasks. This capability is demonstrated by performing the ORU exchange demonstration. HARPS is based on NASREM (NASA Standard Reference Model). All software is developed in Ada, and the project incorporates a number of different CASE (computer-aided software engineering) tools. NASREM was found to be a valid and useful model for building a telerobot control system. Its hierarchical and distributed structure creates a natural and logical flow for implementing large complex robust control systems. The ability of Ada to create and enforce abstraction enhanced the implementation of such control systems.

  14. Multiple target laser ablation system

    DOEpatents

    Mashburn, Douglas N.

    1996-01-01

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film.

  15. Multiple target laser ablation system

    DOEpatents

    Mashburn, D.N.

    1996-01-09

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film. 3 figs.

  16. Constructive Multiple-Choice Testing System

    ERIC Educational Resources Information Center

    Park, Jooyong

    2010-01-01

    The newly developed computerized Constructive Multiple-choice Testing system is introduced. The system combines short answer (SA) and multiple-choice (MC) formats by asking examinees to respond to the same question twice, first in the SA format, and then in the MC format. This manipulation was employed to collect information about the two…

  17. Using Multi-Instance Hierarchical Clustering Learning System to Predict Yeast Gene Function

    PubMed Central

    Liao, Bo; Li, Yun; Jiang, Yan; Cai, Lijun

    2014-01-01

    Time-course gene expression datasets, which record continuous biological processes of genes, have recently been used to predict gene function. However, only few positive genes can be obtained from annotation databases, such as gene ontology (GO). To obtain more useful information and effectively predict gene function, gene annotations are clustered together to form a learnable and effective learning system. In this paper, we propose a novel multi-instance hierarchical clustering (MIHC) method to establish a learning system by clustering GO and compare this method with other learning system establishment methods. Multi-label support vector machine classifier and multi-label K-nearest neighbor classifier are used to verify these methods in four yeast time-course gene expression datasets. The MIHC method shows good performance, which serves as a guide to annotators or refines the annotation in detail. PMID:24621610

  18. Generic-type hierarchical multi digital signal processor system for hard-field tomography.

    PubMed

    Garcia Castillo, Sergio; Ozanyan, Krikor B

    2007-05-01

    This article introduces the design and implementation of a hierarchical multi digital signal processor system aimed to perform parallel multichannel measurements and data processing of the type widely used in hard-field tomography. Details are presented of a complete tomography system with modular and expandable architecture, capable of accommodating a variety of data processing modalities, configured by software. The configuration of the acquisition and processing circuits and the management of the data flow allow a data frame rate of up to 250 kHz. Results of a case study, guided path tomography for temperature mapping, are shown as a direct demonstration of the system's capabilities. Digital lock-in detection is employed for data processing to extract the information from ac measurements of the temperature-induced resistance changes in an array of 32 noninteracting transducers, which is further exported for visualization.

  19. Minimax terminal approach problem in two-level hierarchical nonlinear discrete-time dynamical system

    SciTech Connect

    Shorikov, A. F.

    2015-11-30

    We consider a discrete–time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector nonlinear or linear discrete–time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solving.

  20. Generic-type hierarchical multi digital signal processor system for hard-field tomography

    NASA Astrophysics Data System (ADS)

    Garcia Castillo, Sergio; Ozanyan, Krikor B.

    2007-05-01

    This article introduces the design and implementation of a hierarchical multi digital signal processor system aimed to perform parallel multichannel measurements and data processing of the type widely used in hard-field tomography. Details are presented of a complete tomography system with modular and expandable architecture, capable of accommodating a variety of data processing modalities, configured by software. The configuration of the acquisition and processing circuits and the management of the data flow allow a data frame rate of up to 250kHz. Results of a case study, guided path tomography for temperature mapping, are shown as a direct demonstration of the system's capabilities. Digital lock-in detection is employed for data processing to extract the information from ac measurements of the temperature-induced resistance changes in an array of 32 noninteracting transducers, which is further exported for visualization.

  1. Telerobotic management system: coordinating multiple human operators with multiple robots

    NASA Astrophysics Data System (ADS)

    King, Jamie W.; Pretty, Raymond; Brothers, Brendan; Gosine, Raymond G.

    2003-09-01

    This paper describes an application called the Tele-robotic management system (TMS) for coordinating multiple operators with multiple robots for applications such as underground mining. TMS utilizes several graphical interfaces to allow the user to define a partially ordered plan for multiple robots. This plan is then converted to a Petri net for execution and monitoring. TMS uses a distributed framework to allow robots and operators to easily integrate with the applications. This framework allows robots and operators to join the network and advertise their capabilities through services. TMS then decides whether tasks should be dispatched to a robot or a remote operator based on the services offered by the robots and operators.

  2. Evolutionary Processes in Multiple Systems

    SciTech Connect

    Eggleton, P P; Kisseleva-Eggleton, L

    2006-02-14

    There are several ways in which triple stars can evolve in somewhat unusual ways. They discuss two situations where Case A Roche-lobe overflow, followed by a merger, can produce anomalous wide binaries such as {gamma} Per; and Kozai cycles in triples with non-parallel orbits, which can produce merged rapidly-rotating stars like AB Dor, and which can also lead to the delayed ejection of one component of a multiple, as may have been observed in T Tau in 1998.

  3. A hierarchical clustering algorithm for MIMD architecture.

    PubMed

    Du, Zhihua; Lin, Feng

    2004-12-01

    Hierarchical clustering is the most often used method for grouping similar patterns of gene expression data. A fundamental problem with existing implementations of this clustering method is the inability to handle large data sets within a reasonable time and memory resources. We propose a parallelized algorithm of hierarchical clustering to solve this problem. Our implementation on a multiple instruction multiple data (MIMD) architecture shows considerable reduction in computational time and inter-node communication overhead, especially for large data sets. We use the standard message passing library, message passing interface (MPI) for any MIMD systems.

  4. Marine and Human Systems: Addressing Multiple Scales and Multiple Stressors

    NASA Astrophysics Data System (ADS)

    Hofmann, E. E.; Bundy, A.; Chuenpagdee, R.; Maddison, L.; Svendsen, E.

    2015-12-01

    The Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) project aims to develop a comprehensive understanding of, and predictive capacity of ocean responses to accelerating global change and the consequent effects on the Earth System and human society. Understanding the changing ecology and biogeochemistry of marine ecosystems and their sensitivity and resilience to multiple drivers, pressures and stressors is critical to developing responses that will help reduce the vulnerability of marine-dependent human communities. The cumulative pressure of anthropogenic activities on marine systems is already apparent and is projected to increase in the next decades. Policy- and decision-makers need assessments of the status and trends of marine habitats, species, and ecosystems to promote sustainable human activities in the marine environment, particularly in light of global environmental change and changing social systems and human pressures. The IMBER community recently undertook a synthesis and evaluation of approaches for ecosystem-based marine governance, integrated modeling of marine social-ecological systems, and the social and ecological consequences of changing marine ecosystems. The outcomes of this activity provide assessments of current understanding, indicate approaches needed to predict the effects of multiple stressors, at multiple scales, on marine ecosystems and dependent human populations, and highlight approaches for developing innovative societal responses to changing marine ecosystems.

  5. Hierarchal clustering yields insight into multidrug-resistant bacteria isolated from a cattle feedlot wastewater treatment system.

    PubMed

    Jahne, Michael A; Rogers, Shane W; Ramler, Ivan P; Holder, Edith; Hayes, Gina

    2015-01-01

    Forty-two percent of Escherichia coli and 58% of Enterococcus spp. isolated from cattle feedlot runoff and associated infiltration basin and constructed wetland treatment system were resistant to at least one antibiotic of clinical importance; a high level of multidrug resistance (22% of E. coli and 37% of Enterococcus spp.) was observed. Hierarchical clustering revealed a closely associated resistance cluster among drug-resistant E. coli isolates that included cephalosporins (ceftiofur, cefoxitin, and ceftriaxone), aminoglycosides (gentamycin, kanamycin, and amikacin), and quinolone nalidixic acid; antibiotics from these classes were used at the study site, and cross-resistance may be associated with transferrable multiple-resistance elements. For Enterococcus spp., co-resistance among vancomycin, linezolid, and daptomycin was common; these antibiotics are reserved for complicated clinical infections and have not been approved for animal use. Vancomycin resistance (n = 49) only occurred when isolates were resistant to linezolid, daptomycin, and all four of the MLSB (macrolide-lincosamide-streptogramin B) antibiotics tested (tylosin, erythromycin, lincomycin, and quinipristin/dalfopristin). This suggests that developing co-resistance to MLSB antibiotics along with cyclic lipopeptides and oxazolidinones may result in resistance to vancomycin as well. Effects of the treatment system on antibiotic resistance were pronounced during periods of no rainfall and low flow (long residence time). Increased hydraulic loading (short residence time) under the influence of rain caused antibiotic-resistant bacteria to be flushed through the treatment system. This presents concern for environmental discharge of multidrug-resistant organisms relevant to public health.

  6. [Chirality as a primary switch of hierarchical levels in molecular biological systems].

    PubMed

    Tverdislov, V A

    2013-01-01

    A synergetic law, being of common physicochemical and biological sense, is formulated: any evolving system that possesses an excess of free energy and elements with chiral asymmetry, while being within one hierarchical level, is able to change the type of symmetry in the process of self-organization increasing its complexity but preserving the sign of a prevailing chirality (left - L or right - D twist). The same system tends to form spontaneously a sequence of hierarchical levels with alternating chirality signs of de novo formed structures and with an increase of the structures relative scales. In living systems, the hierarchy of conjugated levels of macromolecular structures that begins from the "lowest" asymmetric carbon serves as an anti-entropic factor as well as the structural basis of "selected mechanical degrees of freedom" in molecular machines. During transition of DNA to a higher level of structural and functional organization regular alterations of the chirality sign D-L-D-L and L-D-L-D for DNA and protein structures, respectively, are observed. Sign-alternating chiral hierarchies of DNA and protein structure, in turn, form a complementary conjugated chiral pair that represents an achiral invariant, that "consummates" the molecular-biological block of living systems. The ability of a carbon atom to form choral compounds is an important factor that determined carbon basis of living systems on the Earth as well as their development though a series of chiral bifurcations. The hierarchy of macromolecular structures demarcated by the chirality sign predetermined the possibility of the "block" character of biological evolution.

  7. Self-assembly of hierarchically ordered structures in DNA nanotube systems

    NASA Astrophysics Data System (ADS)

    Glaser, Martin; Schnauß, Jörg; Tschirner, Teresa; Schmidt, B. U. Sebastian; Moebius-Winkler, Maximilian; Käs, Josef A.; Smith, David M.

    2016-05-01

    The self-assembly of molecular and macromolecular building blocks into organized patterns is a complex process found in diverse systems over a wide range of size and time scales. The formation of star- or aster-like configurations, for example, is a common characteristic in solutions of polymers or other molecules containing multi-scaled, hierarchical assembly processes. This is a recurring phenomenon in numerous pattern-forming systems ranging from cellular constructs to solutions of ferromagnetic colloids or synthetic plastics. To date, however, it has not been possible to systematically parameterize structural properties of the constituent components in order to study their influence on assembled states. Here, we circumvent this limitation by using DNA nanotubes with programmable mechanical properties as our basic building blocks. A small set of DNA oligonucleotides can be chosen to hybridize into micron-length DNA nanotubes with a well-defined circumference and stiffness. The self-assembly of these nanotubes to hierarchically ordered structures is driven by depletion forces caused by the presence of polyethylene glycol. This trait allowed us to investigate self-assembly effects while maintaining a complete decoupling of density, self-association or bundling strength, and stiffness of the nanotubes. Our findings show diverse ranges of emerging structures including heterogeneous networks, aster-like structures, and densely bundled needle-like structures, which compare to configurations found in many other systems. These show a strong dependence not only on concentration and bundling strength, but also on the underlying mechanical properties of the nanotubes. Similar network architectures to those caused by depletion forces in the low-density regime are obtained when an alternative hybridization-based bundling mechanism is employed to induce self-assembly in an isotropic network of pre-formed DNA nanotubes. This emphasizes the universal effect inevitable

  8. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    PubMed Central

    Peng, Jiankun; He, Hongwen; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  9. A hierarchical modeling approach for estimating national distributions of chemicals in public drinking water systems.

    PubMed

    Qian, Song S; Schulman, Andrew; Koplos, Jonathan; Kotros, Alison; Kellar, Penny

    2004-02-15

    Water quality studies often include the analytical challenge of incorporating censored data and quantifying error of estimation. Many analytical methods exist for estimating distribution parameters when censored data are present. This paper presents a Bayesian-based hierarchical model for estimating the national distribution of the mean concentrations of chemicals occurring in U.S. public drinking water systems using fluoride and thallium as examples. The data used are Safe Drinking Water Act compliance monitoring data (with a significant proportion of left-censored data). The model, which assumes log-normality, was evaluated using simulated data sets generated from a series of Weibull distributions to illustrate the robustness of the model. The hierarchical model is easily implemented using the Markov chain Monte Carlo simulation method. In addition, the Bayesian method is able to quantify the uncertainty in the estimated cumulative density function. The estimated fluoride and thallium national distributions are presented. Results from this study can be used to develop prior distributions for future U.S. drinking water regulatory studies of contaminant occurrence.

  10. Hierarchical neural network model of the visual system determining figure/ground relation

    NASA Astrophysics Data System (ADS)

    Kikuchi, Masayuki

    2017-07-01

    One of the most important functions of the visual perception in the brain is figure/ground interpretation from input images. Figural region in 2D image corresponding to object in 3D space are distinguished from background region extended behind the object. Previously the author proposed a neural network model of figure/ground separation constructed on the standpoint that local geometric features such as curvatures and outer angles at corners are extracted and propagated along input contour in a single layer network (Kikuchi & Akashi, 2001). However, such a processing principle has the defect that signal propagation requires manyiterations despite the fact that actual visual system determines figure/ground relation within the short period (Zhou et al., 2000). In order to attain speed-up for determining figure/ground, this study incorporates hierarchical architecture into the previous model. This study confirmed the effect of the hierarchization as for the computation time by simulation. As the number of layers increased, the required computation time reduced. However, such speed-up effect was saturatedas the layers increased to some extent. This study attempted to explain this saturation effect by the notion of average distance between vertices in the area of complex network, and succeeded to mimic the saturation effect by computer simulation.

  11. Distributed Hierarchical Control Architecture for Transient Dynamics Improvement in Power Systems

    SciTech Connect

    Marinovici, Laurentiu D.; Lian, Jianming; Kalsi, Karanjit; Du, Pengwei; Elizondo, Marcelo A.

    2013-08-24

    In this paper, a novel distributed hierarchical coordinated control architecture is proposed for large scale power systems. The newly considered architecture facilitates frequency restoration and power balancing functions to be decoupled and implemented at different levels. At the local level, decentralized robust generator controllers are designed to quickly restore frequency after large faults and disturbances in the system. The controllers presented herein are shown to improve transient stability performance, as compared to conventional governor and excitation control. At the area level, Automatic Generation Control (AGC) is modified and coordinates with the decentralized robust controllers to reach the interchange schedule in the tie lines. The interaction of local and zonal controllers is validated through detailed simulations.

  12. Controlling Hierarchically Self-Assembly in Supramolecular Tailed-Dendron Systems

    NASA Astrophysics Data System (ADS)

    Merlet-Lacroix, Nathalie; Rao, Jingui; Zhang, Afang; Schlüter, Dieter; Ruokolainen, Janne; Mezzenga, Raffaele

    2010-03-01

    We study the self-assembly of a dendritic macromolecular system formed by a second-generation dendron and a polymer chain emanating from its focal point. We use supramolecular ionic interactions to attach to the periphery of the dendrons sulphated alkyl tails. The resulting ``triblock copolymers'' have a molecular architecture similar to a four-arm pitchfork with varying arms and holder lengths. The bulk morphologies observed by SAXS and TEM show thermodynamically stable, hierarchical ``inverted'' hexagonal or lamellar structures. The structural models for the molecular packing emerging from experimental findings are benchmarked to available self-consistent field theories (SCFT) and experiments and theoretical predictions are found in perfect agreement. The present results show that supramolecular systems based on tailed dendrons and surfactants can be used to scale up of the structural organization from the liquid crystalline length scale to the block copolymer length scale, while preserving the inverted unconventional morphologies offering new possibilities in the design of nanostructured materials.

  13. Resilient control of cyber-physical systems against intelligent attacker: a hierarchal stackelberg game approach

    NASA Astrophysics Data System (ADS)

    Yuan, Yuan; Sun, Fuchun; Liu, Huaping

    2016-07-01

    This paper is concerned with the resilient control under denial-of-service attack launched by the intelligent attacker. The resilient control system is modelled as a multi-stage hierarchical game with a corresponding hierarchy of decisions made at cyber and physical layer, respectively. Specifically, the interaction in the cyber layer between different security agents is modelled as a static infinite Stackelberg game, while in the underlying physical layer the full-information H∞ minimax control with package drops is modelled as a different Stackelberg game. Both games are solved sequentially, which is consistent with the actual situations. Finally, the proposed method is applied to the load frequency control of the power system, which demonstrates its effectiveness.

  14. Multiple pass reimaging optical system

    NASA Technical Reports Server (NTRS)

    Gunter, W. D., Jr.; Brown, R. M. (Inventor)

    1973-01-01

    An optical imaging system for enabling nonabsorbed light imaged onto a photodetective surface to be collected and reimaged one or more times onto that surface in register with the original image. The system includes an objective lens, one or more imaging lenses, one or more retroreflectors and perhaps a prism for providing optical matching of the imaging lens focal planes to the photo detective surface.

  15. Marine and Human Systems: Addressing Multiple Scales and Multiple Stressors

    NASA Astrophysics Data System (ADS)

    Hofmann, E. E.; Bundy, A.; Chuenpagdee, R.; Maddison, L.; Svendsen, E.

    2016-02-01

    Understanding the changing ecology and biogeochemistry of marine ecosystems and their sensitivity and resilience to multiple drivers, pressures and stressors is critical to developing responses that will help reduce the vulnerability of marine-dependent human communities. The cumulative pressure of anthropogenic activities on marine systems is already apparent and is projected to increase in the next decades. Policy- and decision-makers need assessments of the status and trends of marine habitats, species, and ecosystems to promote sustainable human activities in the marine environment, particularly in light of global environmental change and changing social systems and human pressures. The Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) science community recently undertook a synthesis and evaluation of approaches for ecosystem-based marine governance, integrated modeling of marine social-ecological systems, and the social and ecological consequences of changing marine ecosystems. The outcomes of this activity provide assessments of current understanding, indicate approaches needed to predict the effects of multiple stressors, at multiple scales, on marine ecosystems and dependent human populations, and highlight approaches for developing innovative societal responses to changing marine ecosystems.

  16. Hierarchical structural health monitoring system combining a fiber optic spinal cord network and distributed nerve cell devices

    NASA Astrophysics Data System (ADS)

    Minakuchi, Shu; Tsukamoto, Haruka; Takeda, Nobuo

    2009-03-01

    This study proposes novel hierarchical sensing concept for detecting damages in composite structures. In the hierarchical system, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with the optical fiber network through transducing mechanisms. The distributed "sensory nerve cell" devices detect the damage, and the fiber optic "spinal cord" network gathers damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of the hierarchical sensing system thorough comparison with existing fiber optic based systems and nerve systems in the animal kingdom. Then, in order to validate the proposed sensing concept, impact damage detection system for the composite structure was proposed. The sensor devices were developed based on Comparative Vacuum Monitoring (CVM) system and the Brillouin based distributed strain sensing was utilized to gather the damage signals from the distributed devices. Finally a verification test was conducted using prototype devices. Occurrence of barely visible impact damage was successfully detected and it was clearly indicated that the hierarchical system has better repairability, higher robustness, and wider monitorable area compared to existing systems utilizing embedded optical fiber sensors.

  17. Retrofitting of multiple control systems

    SciTech Connect

    Sullivan, G.F.; Coles, J.E.

    1984-01-01

    In these days when distributed micro-processor control systems are being hailed as the way to go in new power plants, the question of replacing worn-out and obsolete control systems in existing power plants presents a real dilemma. The cost of these systems and their non-compatibility with much of the existing hardware makes them unattractive for retrofits. After almost a year of study and cost comparisons, it was decided five years ago that the most painless way of resolving that problem in our 15-28 year old plant was to distribute various plant instrumentation and control functions in a few mini-computers and to break this project into several time phases, thereby spreading the capital expenditures over several years. In prosecuting the project, a step backwards was taken from the direction plant instrumentation and controls is heading today, ending up with all of our eggs in one basket - almost, but gaining a quantum increase in control system reliability and performance, plus the capability to add new unrelated loops and functions as required. The system is described.

  18. Secular dynamics in hierarchical three-body systems with mass loss and mass transfer

    SciTech Connect

    Michaely, Erez; Perets, Hagai B.

    2014-10-20

    Recent studies have shown that secular evolution of triple systems can play a major role in the evolution and interaction of their inner binaries. Very few studies explored the stellar evolution of triple systems, and in particular the mass-loss phase of the evolving stellar components. Here we study the dynamical secular evolution of hierarchical triple systems undergoing mass loss. We use the secular evolution equations and include the effects of mass loss and mass transfer, as well as general relativistic effects. We present various evolutionary channels taking place in such evolving triples, and discuss both the effects of mass loss and mass transfer in the inner binary system, as well as the effects of mass loss/transfer from an outer third companion. We discuss several distinct types/regimes of triple secular evolution, where the specific behavior of a triple system can sensitively depend on its hierarchy and the relative importance of classical and general relativistic effects. We show that the orbital changes due to mass-loss and/or mass-transfer processes can effectively transfer a triple system from one dynamical regime to another. In particular, mass loss/transfer can both induce and quench high-amplitude (Lidov-Kozai) variations in the eccentricity and inclination of the inner binaries of evolving triples. They can also change the system dynamics from an orderly periodic behavior to a chaotic one, and vice versa.

  19. Genetics Home Reference: multiple system atrophy

    MedlinePlus

    ... Management Genetic Testing (1 link) Genetic Testing Registry: Shy-Drager syndrome Other Diagnosis and Management Resources (1 ... progressive autonomic failure with multiple system atrophy SDS Shy-Drager syndrome sporadic olivopontocerebellar atrophy Related Information How ...

  20. A SPATIALLY EXPLICIT HIERARCHICAL APPROACH TO MODELING COMPLEX ECOLOGICAL SYSTEMS: THEORY AND APPLICATIONS. (R827676)

    EPA Science Inventory

    Ecological systems are generally considered among the most complex because they are characterized by a large number of diverse components, nonlinear interactions, scale multiplicity, and spatial heterogeneity. Hierarchy theory, as well as empirical evidence, suggests that comp...

  1. Hierarchical Graph Rewriting as a Unifying Tool for Analyzing and Understanding Nondeterministic Systems

    NASA Astrophysics Data System (ADS)

    Ueda, Kazunori; Ayano, Takayuki; Hori, Taisuke; Iwasawa, Hiroki; Ogawa, Seiji

    We have designed and implemented LMNtal (pronounced “elemental”), a language based on hierarchical graph rewriting that allows us to encode diverse computational models involving concurrency, mobility and multiset rewriting. Towards its novel applications, the system has recently evolved into a model checker that employs LMNtal as the modeling language and PLTL as the specification language. The strengths of our LMNtal model checker are its powerful data structure, highly nondeterministic computation it can express, and virtually no discrepancy between programming and modeling languages. Models expressed in Promela, MSR, and Coloured Petri Nets can be easily encoded into LMNtal. The visualizer of the LMNtal IDE turned out to be extremely useful in understanding models by state space browsing. The LMNtal IDE has been used to run and visualize diverse examples taken from the fields of model checking, concurrency and AI search.

  2. Inventory and Billing Systems for Multiple Users.

    ERIC Educational Resources Information Center

    Frazier, Lavon

    Washington State University developed a comprehensive supplies inventory system and a generalized billing system with multiple users in mind. The supplies inventory control system developed for Central Stores, a self-sustaining service center that purchases and warehouses office, laboratory, and hardware supplies, was called AIMS, An Inventory…

  3. Inventory and Billing Systems for Multiple Users.

    ERIC Educational Resources Information Center

    Frazier, Lavon

    Washington State University developed a comprehensive supplies inventory system and a generalized billing system with multiple users in mind. The supplies inventory control system developed for Central Stores, a self-sustaining service center that purchases and warehouses office, laboratory, and hardware supplies, was called AIMS, An Inventory…

  4. Cognitive impairment in multiple system atrophy

    PubMed Central

    Stankovic, Iva; Krismer, Florian; Jesic, Aleksandar; Antonini, Angelo; Benke, Thomas; Brown, Richard G.; Burn, David J.; Holton, Janice L.; Kaufmann, Horacio; Kostic, Vladimir S.; Ling, Helen; Meissner, Wassilios G.; Poewe, Werner; Semnic, Marija; Seppi, Klaus; Takeda, Atsushi; Weintraub, Daniel; Wenning, Gregor K.

    2014-01-01

    Consensus diagnostic criteria for multiple system atrophy consider dementia as a non-supporting feature, despite emerging evidence demonstrating that cognitive impairments are an integral part of the disease. Cognitive disturbances in multiple system atrophy occur across a wide spectrum from mild single domain deficits to impairments in multiple domains and even to frank dementia in some cases. Frontal-executive dysfunction is the most common presentation, while memory and visuospatial functions may also be impaired. Imaging and neuropathological findings support the concept that cognitive impairments in MSA originate from striatofrontal deafferentation with additional contributions from intrinsic cortical degeneration and cerebellar pathology. Based on a comprehensive evidence-based review we here propose future avenues of research that may ultimately lead to diagnostic criteria for cognitive impairment and dementia associated with multiple system atrophy. PMID:24753321

  5. Hand-held multiple system gas chromatograph

    DOEpatents

    Yu, Conrad M.

    2001-01-01

    A multiple parallel hand-held gas chromatograph (GC) system which includes several independent GCs. Each independent GC has its own injector, separation column, detector and oven and the GCs are mounted in a light weight hand-held assembly. Each GC operates independently and simultaneously. Because of different coatings in different separation columns, different retention times for the same gas will be measured. Thus, for a GC system with multiple parallel GCs, the system can measure, in a short period, different retention times and provide a cross-reference in the determination of the measured gas and to become a two-dimensional system for direct field use.

  6. Mastering algebra retrains the visual system to perceive hierarchical structure in equations.

    PubMed

    Marghetis, Tyler; Landy, David; Goldstone, Robert L

    2016-01-01

    Formal mathematics is a paragon of abstractness. It thus seems natural to assume that the mathematical expert should rely more on symbolic or conceptual processes, and less on perception and action. We argue instead that mathematical proficiency relies on perceptual systems that have been retrained to implement mathematical skills. Specifically, we investigated whether the visual system-in particular, object-based attention-is retrained so that parsing algebraic expressions and evaluating algebraic validity are accomplished by visual processing. Object-based attention occurs when the visual system organizes the world into discrete objects, which then guide the deployment of attention. One classic signature of object-based attention is better perceptual discrimination within, rather than between, visual objects. The current study reports that object-based attention occurs not only for simple shapes but also for symbolic mathematical elements within algebraic expressions-but only among individuals who have mastered the hierarchical syntax of algebra. Moreover, among these individuals, increased object-based attention within algebraic expressions is associated with a better ability to evaluate algebraic validity. These results suggest that, in mastering the rules of algebra, people retrain their visual system to represent and evaluate abstract mathematical structure. We thus argue that algebraic expertise involves the regimentation and reuse of evolutionarily ancient perceptual processes. Our findings implicate the visual system as central to learning and reasoning in mathematics, leading us to favor educational approaches to mathematics and related STEM fields that encourage students to adapt, not abandon, their use of perception.

  7. The HD 5980 multiple system: Masses and evolutionary status

    SciTech Connect

    Koenigsberger, Gloria; Gamen, Roberto; Barbá, Rodolfo E-mail: nmorrell@lco.edu E-mail: rgamen@fcaglp.unlp.edu.ar E-mail: ngonzalez@astro.uni-bonn.de E-mail: rbarba@dfuls.cl

    2014-10-01

    New spectroscopic observations of the LBV/WR multiple system HD 5980 in the Small Magellanic Cloud are used to address the question of the masses and evolutionary status of the two very luminous stars in the 19.3 day eclipsing binary system. Two distinct components of the N V 4944 Å line are detected in emission and their radial velocity variations are used to derive masses of 61 and 66 M {sub ☉}, under the assumption that binary interaction effects on this atomic transition are negligible. We propose that this binary system is the product of quasi-chemically homogeneous evolution with little or no mass transfer. Thus, both of these binary stars may be candidates for gamma-ray burst progenitors or even pair instability supernovae. Analysis of the photospheric absorption lines belonging to the third-light object in the system confirm that it consists of an O-type star in a 96.56 day eccentric orbit (e = 0.82) around an unseen companion. The 5:1 period ratio and high eccentricities of the two binaries suggest that they may constitute a hierarchical quadruple system.

  8. Hierarchical statistical analysis of complex analog and mixed-signal systems

    NASA Astrophysics Data System (ADS)

    Webb, Matthew; Tang, Hua

    2014-12-01

    With increasing process parameter variations in nanometre regime, circuits and systems encounter significant performance variations and therefore statistical analysis has become increasingly important. For complex analog and mixed-signal circuits and systems, efficient yet accurate statistical analysis has been a challenge mainly due to significant simulation and modelling time. In the past years, there have been various approaches proposed for statistical analysis of analog and mixed-signal circuits. A recent work is reported to address statistical analysis for continuous-time Delta-Sigma modulators. In this article, we generalise that method and present a hierarchical method for efficient statistical analysis of complex analog and mixed-signal circuits while maintaining reasonable accuracy. At circuit level, we use the response surface modelling method to extract quadratic models of circuit-level performance parameters in terms of process parameters. Then at system level, we use behavioural models and apply the Monte-Carlo method for statistical evaluation of system performance parameters. We illustrate and validate the method on a continuous-time Delta-Sigma modulator and an analog filter.

  9. Hierarchical fiber-optic delamination detection system for carbon fiber reinforced plastic structures

    NASA Astrophysics Data System (ADS)

    Minakuchi, Shu; Banshoya, Hidehiko; Shingo, Ii; Takeda, Nobuo

    2012-10-01

    This study develops a delamination detection system by extending our previous approach for monitoring surface cracks in a large-scale composite structure. In the new system, numerous thin glass capillaries are embedded into a composite structure, and internal pressure in the built-in capillary sensors, based on comparative vacuum monitoring (CVM), is maintained as a vacuum. When delamination is induced, the capillary sensors located within the delaminated area are breached, and atmospheric air flows into the capillaries. The consequent pressure change within the capillaries is then converted into axial strain in a surface-mounted optical fiber through a transducing mechanism, which is connected to the capillaries. By monitoring the strain distribution along the optical fiber, it is possible to identify a transducing mechanism in which the pressure change occurred and thus to specify the location of the delamination. This study begins by establishing a novel sensor embedding/extracting method. The airflow characteristic in the capillary sensors is then comprehensively evaluated, determining the basic performance of the new system. The proposed detection technique is validated by taking a step-by-step approach, and finally the hierarchical fiber-optic delamination detection system is demonstrated. A further advance to be combined with a self-healing concept is also discussed.

  10. Generalized Hill-stability criteria for hierarchical three-body systems at arbitrary inclinations

    NASA Astrophysics Data System (ADS)

    Grishin, Evgeni; Perets, Hagai B.; Zenati, Yossef; Michaely, Erez

    2017-04-01

    A fundamental aspect of the three-body problem is its stability. Most stability studies have focused on the co-planar three-body problem, deriving analytic criteria for the dynamical stability of such pro/retrograde systems. Numerical studies of inclined systems phenomenologically mapped their stability regions, but neither complement it by theoretical framework, nor provided satisfactory fit for their dependence on mutual inclinations. Here we present a novel approach to study the stability of hierarchical three-body systems at arbitrary inclinations, which accounts not only for the instantaneous stability of such systems, but also for the secular stability and evolution through Lidov-Kozai cycles and evection. We generalize the Hill-stability criteria to arbitrarily inclined triple systems, explain the existence of quasi-stable regimes and characterize the inclination dependence of their stability. We complement the analytic treatment with an extensive numerical study, to test our analytic results. We find excellent correspondence up to high inclinations (˜120°), beyond which the agreement is marginal. At such high inclinations, the stability radius is larger, the ratio between the outer and inner periods becomes comparable and our secular averaging approach is no longer strictly valid. We therefore combine our analytic results with polynomial fits to the numerical results to obtain a generalized stability formula for triple systems at arbitrary inclinations. Besides providing a generalized secular-based physical explanation for the stability of non-co-planar systems, our results have direct implications for any triple systems and, in particular, binary planets and moon/satellite systems; we briefly discuss the latter as a test case for our models.

  11. Spacecraft Multiple Array Communication System Performance Analysis

    NASA Technical Reports Server (NTRS)

    Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

    2010-01-01

    The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

  12. Eccentricity growth and orbit flip in near-coplanar hierarchical three-body systems

    SciTech Connect

    Li, Gongjie; Naoz, Smadar; Kocsis, Bence; Loeb, Abraham

    2014-04-20

    The secular dynamical evolution of a hierarchical three-body system in which a distant third object orbits around a binary has been studied extensively, demonstrating that the inner orbit can undergo large eccentricity and inclination oscillations. It was shown before that starting with a circular inner orbit, large mutual inclination (40°-140°) can produce long timescale modulations that drive the eccentricity to extremely large values and can flip the orbit. Here, we demonstrate that starting with an almost coplanar configuration, for eccentric inner and outer orbits, the eccentricity of the inner orbit can still be excited to high values, and the orbit can flip by ∼180°, rolling over its major axis. The ∼180° flip criterion and the flip timescale are described by simple analytic expressions that depend on the initial orbital parameters. With tidal dissipation, this mechanism can produce counter-orbiting exoplanetary systems. In addition, we also show that this mechanism has the potential to enhance the tidal disruption or collision rates for different systems. Furthermore, we explore the entire e {sub 1} and i {sub 0} parameter space that can produce flips.

  13. A high performance hierarchical storage management system for the Canadian tier-1 centre at TRIUMF

    NASA Astrophysics Data System (ADS)

    Deatrich, D. C.; Liu, S. X.; Tafirout, R.

    2010-04-01

    We describe in this paper the design and implementation of Tapeguy, a high performance non-proprietary Hierarchical Storage Management (HSM) system which is interfaced to dCache for efficient tertiary storage operations. The system has been successfully implemented at the Canadian Tier-1 Centre at TRIUMF. The ATLAS experiment will collect a large amount of data (approximately 3.5 Petabytes each year). An efficient HSM system will play a crucial role in the success of the ATLAS Computing Model which is driven by intensive large-scale data analysis activities that will be performed on the Worldwide LHC Computing Grid infrastructure continuously. Tapeguy is Perl-based. It controls and manages data and tape libraries. Its architecture is scalable and includes Dataset Writing control, a Read-back Queuing mechanism and I/O tape drive load balancing as well as on-demand allocation of resources. A central MySQL database records metadata information for every file and transaction (for audit and performance evaluation), as well as an inventory of library elements. Tapeguy Dataset Writing was implemented to group files which are close in time and of similar type. Optional dataset path control dynamically allocates tape families and assign tapes to it. Tape flushing is based on various strategies: time, threshold or external callbacks mechanisms. Tapeguy Read-back Queuing reorders all read requests by using an elevator algorithm, avoiding unnecessary tape loading and unloading. Implementation of priorities will guarantee file delivery to all clients in a timely manner.

  14. Coordinated Voltage Control of Transformer Taps on account of Hierarchical Structure in Power System

    NASA Astrophysics Data System (ADS)

    Nakachi, Yoshiki; Kato, Satoshi; Ukai, Hiroyuki

    Participation of distributed generators (DG), such as wind turbines, co-generation system etc., is natural trend from ecological point of view and will increase more and more. The outputs of these DGs mainly depend on weather condition but don't correspond to the changes of electrical load demand necessarily. On the other hand, due to the deregulation of electric power market, the power flow in power system will uncertainly vary with several power transactions. Thus, complex power flow by DGs or transactions will cause the voltage deviation. It will be difficult to sustain the voltage quality by using the conventional voltage/reactive power control in near future. In this paper, in order to avoid such a voltage deviation and to decrease the frequency of transformer tap actions, the coordinated voltage control scheme of transformer taps on account of hierarchical structure in power system is proposed. In the proposed scheme, integral of voltage deviation at each layer bus is applied to decide the timing of each transformer tap action. It is confirmed by some numerical simulations that the proposed scheme is able to respond to every conditions on voltage deviation.

  15. A Hierarchical Auction-Based Mechanism for Real-Time Resource Allocation in Cloud Robotic Systems.

    PubMed

    Wang, Lujia; Liu, Ming; Meng, Max Q-H

    2017-02-01

    Cloud computing enables users to share computing resources on-demand. The cloud computing framework cannot be directly mapped to cloud robotic systems with ad hoc networks since cloud robotic systems have additional constraints such as limited bandwidth and dynamic structure. However, most multirobotic applications with cooperative control adopt this decentralized approach to avoid a single point of failure. Robots need to continuously update intensive data to execute tasks in a coordinated manner, which implies real-time requirements. Thus, a resource allocation strategy is required, especially in such resource-constrained environments. This paper proposes a hierarchical auction-based mechanism, namely link quality matrix (LQM) auction, which is suitable for ad hoc networks by introducing a link quality indicator. The proposed algorithm produces a fast and robust method that is accurate and scalable. It reduces both global communication and unnecessary repeated computation. The proposed method is designed for firm real-time resource retrieval for physical multirobot systems. A joint surveillance scenario empirically validates the proposed mechanism by assessing several practical metrics. The results show that the proposed LQM auction outperforms state-of-the-art algorithms for resource allocation.

  16. Pulp regeneration in a full-length human tooth root using a hierarchical nanofibrous microsphere system.

    PubMed

    Li, Xiangwei; Ma, Chi; Xie, Xiaohua; Sun, Hongchen; Liu, Xiaohua

    2016-04-15

    While pulp regeneration using tissue engineering strategy has been explored for over a decade, successful regeneration of pulp tissues in a full-length human root with a one-end seal that truly simulates clinical endodontic treatment has not been achieved. To address this challenge, we designed and synthesized a unique hierarchical growth factor-loaded nanofibrous microsphere scaffolding system. In this system, vascular endothelial growth factor (VEGF) binds with heparin and is encapsulated in heparin-conjugated gelatin nanospheres, which are further immobilized in the nanofibers of an injectable poly(l-lactic acid) (PLLA) microsphere. This hierarchical microsphere system not only protects the VEGF from denaturation and degradation, but also provides excellent control of its sustained release. In addition, the nanofibrous PLLA microsphere integrates the extracellular matrix-mimicking architecture with a highly porous injectable form, efficiently accommodating dental pulp stem cells (DPSCs) and supporting their proliferation and pulp tissue formation. Our in vivo study showed the successful regeneration of pulp-like tissues that fulfilled the entire apical and middle thirds and reached the coronal third of the full-length root canal. In addition, a large number of blood vessels were regenerated throughout the canal. For the first time, our work demonstrates the success of pulp tissue regeneration in a full-length root canal, making it a significant step toward regenerative endodontics. The regeneration of pulp tissues in a full-length tooth root canal has been one of the greatest challenges in the field of regenerative endodontics, and one of the biggest barriers for its clinical application. In this study, we developed a unique approach to tackle this challenge, and for the first time, we successfully regenerated living pulp tissues in a full-length root canal, making it a significant step toward regenerative endodontics. This study will make positive scientific

  17. Secular dynamics of hierarchical quadruple systems: the case of a triple system orbited by a fourth body

    NASA Astrophysics Data System (ADS)

    Hamers, Adrian S.; Perets, Hagai B.; Antonini, Fabio; Portegies Zwart, Simon F.

    2015-06-01

    We study the secular gravitational dynamics of quadruple systems consisting of a hierarchical triple system orbited by a fourth body. These systems can be decomposed into three binary systems with increasing semimajor axes, binaries A, B and C. The Hamiltonian of the system is expanded in ratios of the three binary separations, and orbit averaged. Subsequently, we numerically solve the equations of motion. We study highly hierarchical systems that are well described by the lowest order terms in the Hamiltonian. We find that the qualitative behaviour is determined by the ratio {R}_0 of the initial Kozai-Lidov (KL) time-scales of the binary pairs AB and BC. If {R}_0≪ 1, binaries AB remain coplanar if this is initially the case, and KL eccentricity oscillations in binary B are efficiently quenched. If {R}_0≫ 1, binaries AB become inclined, even if initially coplanar. However, there are no induced KL eccentricity oscillations in binary A. Lastly, if {R}_0˜ 1, complex KL eccentricity oscillations can occur in binary A that are coupled with the KL eccentricity oscillations in B. Even if binaries A and B are initially coplanar, the induced inclination can result in very high eccentricity oscillations in binary A. These extreme eccentricities could have significant implications for strong interactions such as tidal interactions, gravitational wave dissipation, and collisions and mergers of stars and compact objects. As an example, we apply our results to a planet+moon system orbiting a central star, which in turn is orbited by a distant and inclined stellar companion or planet, and to observed stellar quadruples.

  18. Hierarchical auxetic mechanical metamaterials.

    PubMed

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I; Azzopardi, Keith M; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N

    2015-02-11

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts.

  19. Hierarchical Auxetic Mechanical Metamaterials

    NASA Astrophysics Data System (ADS)

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I.; Azzopardi, Keith M.; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N.

    2015-02-01

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts.

  20. Hierarchical Auxetic Mechanical Metamaterials

    PubMed Central

    Gatt, Ruben; Mizzi, Luke; Azzopardi, Joseph I.; Azzopardi, Keith M.; Attard, Daphne; Casha, Aaron; Briffa, Joseph; Grima, Joseph N.

    2015-01-01

    Auxetic mechanical metamaterials are engineered systems that exhibit the unusual macroscopic property of a negative Poisson's ratio due to sub-unit structure rather than chemical composition. Although their unique behaviour makes them superior to conventional materials in many practical applications, they are limited in availability. Here, we propose a new class of hierarchical auxetics based on the rotating rigid units mechanism. These systems retain the enhanced properties from having a negative Poisson's ratio with the added benefits of being a hierarchical system. Using simulations on typical hierarchical multi-level rotating squares, we show that, through design, one can control the extent of auxeticity, degree of aperture and size of the different pores in the system. This makes the system more versatile than similar non-hierarchical ones, making them promising candidates for industrial and biomedical applications, such as stents and skin grafts. PMID:25670400

  1. RESONANT POST-NEWTONIAN ECCENTRICITY EXCITATION IN HIERARCHICAL THREE-BODY SYSTEMS

    SciTech Connect

    Naoz, Smadar; Kocsis, Bence; Loeb, Abraham; Yunes, Nicolas

    2013-08-20

    We study the secular, hierarchical three-body problem to first-order in a post-Newtonian expansion of general relativity (GR). We expand the first-order post-Newtonian Hamiltonian to leading-order in the ratio of the semi-major axis of the two orbits. In addition to the well-known terms that correspond to the GR precession of the inner and outer orbits, we find a new secular post-Newtonian interaction term that can affect the long-term evolution of the triple. We explore the parameter space for highly inclined and eccentric systems, where the Kozai-Lidov mechanism can produce large-amplitude oscillations in the eccentricities. The standard lore, i.e., that GR effects suppress eccentricity, is only consistent with the parts of phase space where the GR timescales are several orders of magnitude shorter than the secular Newtonian one. In other parts of phase space, however, post-Newtonian corrections combined with the three-body ones can excite eccentricities. In particular, for systems where the GR timescale is comparable to the secular Newtonian timescales, the three-body interactions give rise to a resonant-like eccentricity excitation. Furthermore, for triples with a comparable-mass inner binary, where the eccentric Kozai-Lidov mechanism is suppressed, post-Newtonian corrections can further increase the eccentricity and lead to orbital flips even when the timescale of the former is much longer than the timescale of the secular Kozai-Lidov quadrupole perturbations.

  2. Vibration interaction in a multiple flywheel system

    NASA Astrophysics Data System (ADS)

    Firth, Jordan; Black, Jonathan

    2012-03-01

    This paper investigates vibration interaction in a multiple flywheel system. Flywheels can be used for kinetic energy storage in a satellite Integrated Power and Attitude Control System (IPACS). One hitherto unstudied problem with IPACS is vibration interaction between multiple unbalanced wheels. This paper uses a linear state-space dynamics model to study the impact of vibration interaction. Specifically, imbalance-induced vibration inputs in one flywheel rotor are used to cause a resonant whirling vibration in another rotor. Extra-synchronous resonant vibrations are shown to exist, but with damping modeled the effect is minimal. Vibration is most severe when both rotors are spinning in the same direction.

  3. Restless legs syndrome in multiple system atrophy.

    PubMed

    Ghorayeb, Imad; Dupouy, Sandrine; Tison, François; Meissner, Wassilios G

    2014-12-01

    The purpose of the study was to evaluate the frequency of restless legs syndrome in 30 patients with multiple system atrophy. Eight patients complained from restless legs syndrome, their severity score was 19.4 ± 4.1. Pittsburgh Sleep Quality Index scores were significantly higher in patients with restless legs syndrome than those without (9.3 ± 3.7 vs. 4.8 ± 2.9, p = 0.00165). Periodic limb movements were found in 75% of patients with restless legs syndrome. Restless legs syndrome is more prevalent in multiple system atrophy as compared to the acknowledged prevalence in the general population.

  4. Formation of Black Hole Low-mass X-Ray Binaries in Hierarchical Triple Systems

    NASA Astrophysics Data System (ADS)

    Naoz, Smadar; Fragos, Tassos; Geller, Aaron; Stephan, Alexander P.; Rasio, Frederic A.

    2016-05-01

    The formation of black hole (BH) low-mass X-ray binaries (LMXB) poses a theoretical challenge, as low-mass companions are not expected to survive the common-envelope scenario with the BH progenitor. Here we propose a formation mechanism that skips the common-envelope scenario and relies on triple-body dynamics. We study the evolution of hierarchical triples following the secular dynamical evolution up to the octupole-level of approximation, including general relativity, tidal effects, and post-main-sequence evolution such as mass loss, changes to stellar radii, and supernovae. During the dynamical evolution of the triple system the “eccentric Kozai-Lidov” mechanism can cause large eccentricity excitations in the LMXB progenitor, resulting in three main BH-LMXB formation channels. Here we define BH-LMXB candidates as systems where the inner BH-companion star crosses its Roche limit. In the “eccentric” channel (˜81% of the LMXBs in our simulations) the donor star crosses its Roche limit during an extreme eccentricity excitation while still on a wide orbit. Second, we find a “giant” LMXB channel (˜11%), where a system undergoes only moderate eccentricity excitations but the donor star fills its Roche-lobe after evolving toward the giant branch. Third, we identify a “classical” channel (˜8%), where tidal forces and magnetic braking shrink and circularize the orbit to short periods, triggering mass-transfer. Finally, for the giant channel we predict an eccentric (˜0.3-0.6) preferably inclined (˜40°, ˜140°) tertiary, typically on a wide enough orbit (˜104 au) to potentially become unbound later in the triple evolution. While this initial study considers only one representative system and neglects BH natal kicks, we expect our scenario to apply across a broad region of parameter space for triple-star systems.

  5. User's Satisfaction of Multiple Accounting Record System.

    PubMed

    Chen, M C; Yu, H C

    2016-01-01

    The study hospital had developed a multiple account recording system that generates the accounting information of the consumed materials based on daily nursing records. A questionnaire survey was delivered to further investigate the impact of the system. Four concepts of the system were investigated. (1) Supportive and time saving; (2) impact on workflows and job satisfactions; (3) ease of use; and (4) overall satisfactions. The system scored 4.03 out of 5 as the highest for helpfulness for daily practices, 3.98 for decrease the time for recording material consumptions, 3.98 for actually changed the way they work. Users mostly expressed positive attitude towards the system.

  6. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

    Pattipati, Krishna R.; Patterson-Hine, Ann; Iverson, David

    1997-01-01

    Fault diagnosis in large-scale systems that are products of modern technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

  7. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

    Pattipati, Krishna R.

    1997-01-01

    Fault diagnosis in large-scale systems that are products of modem technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

  8. Dynamic resource allocation in a hierarchical multiprocessor system: A preliminary study

    NASA Technical Reports Server (NTRS)

    Ngai, Tin-Fook

    1986-01-01

    An integrated system approach to dynamic resource allocation is proposed. Some of the problems in dynamic resource allocation and the relationship of these problems to system structures are examined. A general dynamic resource allocation scheme is presented. A hierarchial system architecture which dynamically maps between processor structure and programs at multiple levels of instantiations is described. Simulation experiments were conducted to study dynamic resource allocation on the proposed system. Preliminary evaluation based on simple dynamic resource allocation algorithms indicates that with the proposed system approach, the complexity of dynamic resource management could be significantly reduced while achieving reasonable effective dynamic resource allocation.

  9. Hierarchical capillary adhesion of microcantilevers or hairs

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Lin; Feng, Xi-Qiao; Xia, Re; Zhao, Hong-Ping

    2007-09-01

    As a result of capillary forces, animal hairs, carbon nanotubes or nanowires of a periodically or randomly distributed array often assemble into hierarchical structures. In this paper, the energy method is adopted to analyse the capillary adhesion of microsized hairs, which are modelled as clamped microcantilevers wetted by liquids. The critical conditions for capillary adhesion of two hairs, three hairs or two bundles of hairs are derived in terms of Young's contact angle, elastic modulus and geometric sizes of the beams. Then, the hierarchical capillary adhesion of hairs is addressed. It is found that for multiple hairs or microcantilevers, the system tends to take a hierarchical structure as a result of the minimization of the total potential energy of the system. The level number of structural hierarchy increases with the increase in the number of hairs if they are sufficiently long. Additionally, we performed experiments to verify our theoretical solutions for the adhesion of microbeams.

  10. Synchronization of chaotic systems and identification of nonlinear systems by using recurrent hierarchical type-2 fuzzy neural networks.

    PubMed

    Mohammadzadeh, Ardashir; Ghaemi, Sehraneh

    2015-09-01

    This paper proposes a novel approach for training of proposed recurrent hierarchical interval type-2 fuzzy neural networks (RHT2FNN) based on the square-root cubature Kalman filters (SCKF). The SCKF algorithm is used to adjust the premise part of the type-2 FNN and the weights of defuzzification and the feedback weights. The recurrence property in the proposed network is the output feeding of each membership function to itself. The proposed RHT2FNN is employed in the sliding mode control scheme for the synchronization of chaotic systems. Unknown functions in the sliding mode control approach are estimated by RHT2FNN. Another application of the proposed RHT2FNN is the identification of dynamic nonlinear systems. The effectiveness of the proposed network and its learning algorithm is verified by several simulation examples. Furthermore, the universal approximation of RHT2FNNs is also shown.

  11. Design of a Multiple Input-Multiple Output Flight Control System Containing Uncertain Parameters.

    DTIC Science & Technology

    1984-11-01

    MULTIPLE INPUT - MULTIPLE OUTPUT ( MIMO ) SYSTEM... ......... 31 1. Introduction. ...................... 31 2...find design bounds analytically a (L) loop transmission i at flight condition j L nominal loop transmission 0 MIMO multiple input - multiple output M P...aircraft (12). The U. S. Air Force is interested in this technique as a method to * synthesize multiple input - multiple output ( MIMO ) controllers. In

  12. An effective and secure key-management scheme for hierarchical access control in E-medicine system.

    PubMed

    Odelu, Vanga; Das, Ashok Kumar; Goswami, Adrijit

    2013-04-01

    Recently several hierarchical access control schemes are proposed in the literature to provide security of e-medicine systems. However, most of them are either insecure against 'man-in-the-middle attack' or they require high storage and computational overheads. Wu and Chen proposed a key management method to solve dynamic access control problems in a user hierarchy based on hybrid cryptosystem. Though their scheme improves computational efficiency over Nikooghadam et al.'s approach, it suffers from large storage space for public parameters in public domain and computational inefficiency due to costly elliptic curve point multiplication. Recently, Nikooghadam and Zakerolhosseini showed that Wu-Chen's scheme is vulnerable to man-in-the-middle attack. In order to remedy this security weakness in Wu-Chen's scheme, they proposed a secure scheme which is again based on ECC (elliptic curve cryptography) and efficient one-way hash function. However, their scheme incurs huge computational cost for providing verification of public information in the public domain as their scheme uses ECC digital signature which is costly when compared to symmetric-key cryptosystem. In this paper, we propose an effective access control scheme in user hierarchy which is only based on symmetric-key cryptosystem and efficient one-way hash function. We show that our scheme reduces significantly the storage space for both public and private domains, and computational complexity when compared to Wu-Chen's scheme, Nikooghadam-Zakerolhosseini's scheme, and other related schemes. Through the informal and formal security analysis, we further show that our scheme is secure against different attacks and also man-in-the-middle attack. Moreover, dynamic access control problems in our scheme are also solved efficiently compared to other related schemes, making our scheme is much suitable for practical applications of e-medicine systems.

  13. Secular chaotic dynamics in hierarchical quadruple systems, with applications to hot Jupiters in stellar binaries and triples

    NASA Astrophysics Data System (ADS)

    Hamers, Adrian S.; Lai, Dong

    2017-09-01

    Hierarchical quadruple systems arise naturally in stellar binaries and triples that harbour planets. Examples are hot Jupiters (HJs) in stellar triple systems, and planetary companions to HJs in stellar binaries. The secular dynamical evolution of these systems is generally complex, with secular chaotic motion possible in certain parameter regimes. The latter can lead to extremely high eccentricities and, therefore, strong interactions such as efficient tidal evolution. These interactions are believed to play an important role in the formation of HJs through high-eccentricity migration. Nevertheless, a deeper understanding of the secular dynamics of these systems is still lacking. Here, we study in detail the secular dynamics of a special case of hierarchical quadruple systems in either the '2+2' or '3+1' configurations. We show how the equations of motion can be cast in a form representing a perturbed hierarchical three-body system, in which the outer orbital angular-momentum vector is precessing steadily around a fixed axis. In this case, we show that eccentricity excitation can be significantly enhanced when the precession period is comparable to the Lidov-Kozai oscillation time-scale of the inner orbit. This arises from an induced large mutual inclination between the inner and outer orbits driven by the precession of the outer orbit, even if the initial mutual inclination is small. We present a simplified semi-analytic model that describes the latter phenomenon.

  14. Multiple Intelligences Theory in Turkish Education System

    ERIC Educational Resources Information Center

    Kaya, Osman Nafiz

    2006-01-01

    Turkey can be regarded as a cultural bridge between the East and the West. After Turkish Republic was established by Ataturk in 1923, many radical revolutions, including the Turkish Education System, were made in order for Turkey to reach the level of contemporary civilizations. In the last two decades, Multiple Intelligences (MI) theory has been…

  15. Stress Effects on Multiple Memory System Interactions

    PubMed Central

    Ness, Deborah; Calabrese, Pasquale

    2016-01-01

    Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory systems, we review recent animal and human studies exploring the effects of stress on multiple memory systems. Apart from discussing the interaction between distinct memory systems in stressful situations, we will also outline the fundamental role of the amygdala in mediating such stress effects. Additionally, based on the methods applied in the herein discussed studies, we will discuss how memory translates into behaviour. PMID:27034845

  16. Orotidine-Containing RNA: Implications for the Hierarchical Selection (Systems Chemistry Emergence) of RNA.

    PubMed

    Kim, Eun-Kyong; Martin, Vincent; Krishnamurthy, Ramanarayanan

    2017-09-12

    The prebiotic synthesis of canonical nucleobases from HCN is a cornerstone for the RNA world hypothesis. However, their role in the primordial pathways to RNA is still debated. The very same process starting from HCN also gives rise to orotic acid, which (via orotidine) plays a crucial role in extant biology in the de novo synthesis of uridine and cytidine, the informational base-pairs in RNA. However, orotidine itself is absent in RNA. Given the prebiotic and biological relevance of orotic acid vis-à-vis uracil, we investigated orotidine-containing RNA oligonucleotides and show that they have severely compromised base-pairing properties. While not unexpected, these results suggest that the emergence of extant RNA cannot just be a consequence of the plausible prebiotic formation of its chemical constituents/building blocks. In combination with other investigations on alternative prebiotic nucleobases, sugars, and linkers, these findings imply that the selection of the components of extant RNA occurred at a higher hierarchical level of an oligomer/polymer based on its functional properties-pointing to a systems chemistry emergence of RNA from a library of precursors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Biological Chitin-MOF Composites with Hierarchical Pore Systems for Air-Filtration Applications.

    PubMed

    Wisser, Dorothea; Wisser, Florian M; Raschke, Silvia; Klein, Nicole; Leistner, Matthias; Grothe, Julia; Brunner, Eike; Kaskel, Stefan

    2015-10-19

    Metal-organic frameworks (MOFs) are promising materials for gas-separation and air-filtration applications. However, for these applications, MOF crystallites need to be incorporated in robust and manageable support materials. We used chitin-based networks from a marine sponge as a non-toxic, biodegradable, and low-weight support material for MOF deposition. The structural properties of the material favor predominant nucleation of the MOF crystallites at the inside of the hollow fibers. This composite has a hierarchical pore system with surface areas up to 800 m(2)  g(-1) and pore volumes of 3.6 cm(3)  g(-1) , allowing good transport kinetics and a very high loading of the active material. Ammonia break-through experiments highlight the accessibility of the MOF crystallites and the adsorption potential of the composite indicating their high potential for filtration applications for toxic industrial gases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Orbits of Four Young Triple-lined Multiple Systems

    NASA Astrophysics Data System (ADS)

    Tokovinin, Andrei

    2016-07-01

    Each of the nearby triple systems HIP 7601, 13498, 23824, and 113597 (HD 10800, 18198, 35877, 217379) consist of solar-type dwarfs with comparable masses, where all three components are resolved spectrally, while the outer pairs are resolved both visually and spectrally. These stars are relatively young (between 100 and 600 Myr) and chromospherically active (X-ray sources), although they rotate slowly. I determine the spectroscopic orbits of the inner subsystems (periods 19.4, 14.1, 5.6, 20.3 days) and the orbits of the outer systems (periods 1.75, 51, 27, 500 years, respectively). For HIP 7601 and 13498, the combined spectro-interferometric outer orbits produce direct measurement of the masses of all of the components, allowing for a comparison with stellar models. The 6708 Å lithium line is present and its strength is measured in each component individually by subtracting the contributions of the other components. The inner and outer orbits of HIP 7601 are nearly circular, likely co-planar, and have a modest period ratio of 1:33. This study contributes to the characterization of hierarchical multiplicity in the solar neighborhood and provides data for testing stellar evolutionary models and chronology.

  19. Cepheids in Multiple Systems: ADS 14859

    DTIC Science & Technology

    2006-11-01

    rights reserved. Printed in U.S.A. Cepheids in Multiple Systems: ADS 148591 Nancy Remage Evans Smithsonian Astrophysical Observatory, MS-4, 60 Garden...and Center for High Angular Resolution Astronomy , Georgia State University, Atlanta, GA 30303 Richard L. Walker US Naval Observatory. Deceased and...published 2006 November 7 ABSTRACT. We have attempted to resolve the system containing the Cepheid V1334 Cyg (pADS 14859) using both the Faint Object

  20. Spiking neural P systems with multiple channels.

    PubMed

    Peng, Hong; Yang, Jinyu; Wang, Jun; Wang, Tao; Sun, Zhang; Song, Xiaoxiao; Luo, Xiaohui; Huang, Xiangnian

    2017-11-01

    Spiking neural P systems (SNP systems, in short) are a class of distributed parallel computing systems inspired from the neurophysiological behavior of biological spiking neurons. In this paper, we investigate a new variant of SNP systems in which each neuron has one or more synaptic channels, called spiking neural P systems with multiple channels (SNP-MC systems, in short). The spiking rules with channel label are introduced to handle the firing mechanism of neurons, where the channel labels indicate synaptic channels of transmitting the generated spikes. The computation power of SNP-MC systems is investigated. Specifically, we prove that SNP-MC systems are Turing universal as both number generating and number accepting devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. MODEM: a multi-agent hierarchical structure to model the human motor control system.

    PubMed

    Emadi Andani, Mehran; Bahrami, Fariba; Jabehdar Maralani, Parviz; Ijspeert, Auke Jan

    2009-12-01

    In this study, based on behavioral and neurophysiological facts, a new hierarchical multi-agent architecture is proposed to model the human motor control system. Performance of the proposed structure is investigated by simulating the control of sit to stand movement. To develop the model, concepts of mixture of experts, modular structure, and some aspects of equilibrium point hypothesis were brought together. We have called this architecture MODularized Experts Model (MODEM). Human motor system is modeled at the joint torque level and the role of the muscles has been embedded in the function of the joint compliance characteristics. The input to the motor system, i.e., the central command, is the reciprocal command. At the lower level, there are several experts to generate the central command to control the task according to the details of the movement. The number of experts depends on the task to be performed. At the higher level, a "gate selector" block selects the suitable subordinate expert considering the context of the task. Each expert consists of a main controller and a predictor as well as several auxiliary modules. The main controller of an expert learns to control the performance of a given task by generating appropriate central commands under given conditions and/or constraints. The auxiliary modules of this expert learn to scrutinize the generated central command by the main controller. Auxiliary modules increase their intervention to correct the central command if the movement error is increased due to an external disturbance. Each auxiliary module acts autonomously and can be interpreted as an agent. Each agent is responsible for one joint and, therefore, the number of the agents of each expert is equal to the number of joints. Our results indicate that this architecture is robust against external disturbances, signal-dependent noise in sensory information, and changes in the environment. We also discuss the neurophysiological and behavioral basis of

  2. Accurate crop classification using hierarchical genetic fuzzy rule-based systems

    NASA Astrophysics Data System (ADS)

    Topaloglou, Charalampos A.; Mylonas, Stelios K.; Stavrakoudis, Dimitris G.; Mastorocostas, Paris A.; Theocharis, John B.

    2014-10-01

    This paper investigates the effectiveness of an advanced classification system for accurate crop classification using very high resolution (VHR) satellite imagery. Specifically, a recently proposed genetic fuzzy rule-based classification system (GFRBCS) is employed, namely, the Hierarchical Rule-based Linguistic Classifier (HiRLiC). HiRLiC's model comprises a small set of simple IF-THEN fuzzy rules, easily interpretable by humans. One of its most important attributes is that its learning algorithm requires minimum user interaction, since the most important learning parameters affecting the classification accuracy are determined by the learning algorithm automatically. HiRLiC is applied in a challenging crop classification task, using a SPOT5 satellite image over an intensively cultivated area in a lake-wetland ecosystem in northern Greece. A rich set of higher-order spectral and textural features is derived from the initial bands of the (pan-sharpened) image, resulting in an input space comprising 119 features. The experimental analysis proves that HiRLiC compares favorably to other interpretable classifiers of the literature, both in terms of structural complexity and classification accuracy. Its testing accuracy was very close to that obtained by complex state-of-the-art classification systems, such as the support vector machines (SVM) and random forest (RF) classifiers. Nevertheless, visual inspection of the derived classification maps shows that HiRLiC is characterized by higher generalization properties, providing more homogeneous classifications that the competitors. Moreover, the runtime requirements for producing the thematic map was orders of magnitude lower than the respective for the competitors.

  3. The immune system--multiple sites but one system.

    PubMed

    Harleman, Johannes H

    2006-07-01

    Recently several guidelines were published on immunotoxicity. Validation studies have shown that detailed extended examination of the immune system is able to flag immunotoxic compounds. Parameters of the examination are presented. In the final examination it is important that the whole immune system is evaluated as one functional system--multiple sites but one system.

  4. Multiple driver distractions: a systemic transport problem.

    PubMed

    Lansdown, Terry C; Stephens, Amanda N; Walker, Guy H

    2015-01-01

    Strategies to contend with driver distraction may no longer be sufficient for the emerging variety of contemporary driver distractions. A more systematic and systemic approach holds promise for improved road safety but is not currently being developed. This systematic review of multiple driver distractions aims to address this gap and presents two key findings. Systematic classification of distracting tasks with respect to driving is challenging, and engagement with Multiple-Additional-to-Driving (MAD) tasks is almost universally detrimental to driving performance. A model is presented to assist in systematically characterising multiple driver demands. Identified literature is placed into context using the model and shortfalls are identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Variation in mating system among birds: ecological basis revealed by hierarchical comparative analysis of mate desertion

    PubMed Central

    Owens, I. P. F.; Bennett, P. M.

    1997-01-01

    Since most bird species are socially monogamous, variation among species in social mating systems is determined largely by variation in the frequency of mate desertion. Mate desertion is expected to occur when the benefits, in terms of additional reproductive opportunities, outweigh the costs, in terms of reduced reproductive success from the present brood. However, despite much research, the relative importance of costs and benefits in explaining mating system variation is not well understood. Here, we investigate this problem using a comparative method. We analyse changes in the frequency of mate desertion at different phylogenetic levels. Differences between orders and families in the frequency of desertion are negatively associated with changes in the potential costs of desertion, but are not associated with changes in the potential benefits of desertion. Conversely, differences among genera and species in the frequency of desertion are positively associated with increases in the potential benefits of desertion, but not with changes in the potential costs of desertion. Hence, we suggest that mate desertion in birds originates through a combination of evolutionary predisposition and ecological facilitation. In particular, ancient changes in life-history strategy determine the costs of desertion and predispose certain lineages to polygamy, while contemporary changes in the distribution of resources determine the benefits of desertion and thereby the likelihood that polygamy will be viable within these lineages. Thus, monogamy can arise via two very different evolutionary pathways. Groups such as albatrosses (Procellariidae) are constrained to social monogamy by the high cost to desertion, irrespective of the potential benefits. However, in groups such as the accentors (Prunellidae), which are predisposed to desertion, monogamy occurs only when the benefits of desertion are very limited. These conclusions emphasise the additional power which a hierarchical

  6. Perception and Hierarchical Dynamics

    PubMed Central

    Kiebel, Stefan J.; Daunizeau, Jean; Friston, Karl J.

    2009-01-01

    In this paper, we suggest that perception could be modeled by assuming that sensory input is generated by a hierarchy of attractors in a dynamic system. We describe a mathematical model which exploits the temporal structure of rapid sensory dynamics to track the slower trajectories of their underlying causes. This model establishes a proof of concept that slowly changing neuronal states can encode the trajectories of faster sensory signals. We link this hierarchical account to recent developments in the perception of human action; in particular artificial speech recognition. We argue that these hierarchical models of dynamical systems are a plausible starting point to develop robust recognition schemes, because they capture critical temporal dependencies induced by deep hierarchical structure. We conclude by suggesting that a fruitful computational neuroscience approach may emerge from modeling perception as non-autonomous recognition dynamics enslaved by autonomous hierarchical dynamics in the sensorium. PMID:19649171

  7. MPACT Fast Neutron Multiplicity System Prototype Development

    SciTech Connect

    D.L. Chichester; S.A. Pozzi; J.L. Dolan; M.T. Kinlaw; S.J. Thompson; A.C. Kaplan; M. Flaska; A. Enqvist; J.T. Johnson; S.M. Watson

    2013-09-01

    This document serves as both an FY2103 End-of-Year and End-of-Project report on efforts that resulted in the design of a prototype fast neutron multiplicity counter leveraged upon the findings of previous project efforts. The prototype design includes 32 liquid scintillator detectors with cubic volumes 7.62 cm in dimension configured into 4 stacked rings of 8 detectors. Detector signal collection for the system is handled with a pair of Struck Innovative Systeme 16-channel digitizers controlled by in-house developed software with built-in multiplicity analysis algorithms. Initial testing and familiarization of the currently obtained prototype components is underway, however full prototype construction is required for further optimization. Monte Carlo models of the prototype system were performed to estimate die-away and efficiency values. Analysis of these models resulted in the development of a software package capable of determining the effects of nearest-neighbor rejection methods for elimination of detector cross talk. A parameter study was performed using previously developed analytical methods for the estimation of assay mass variance for use as a figure-of-merit for system performance. A software package was developed to automate these calculations and ensure accuracy. The results of the parameter study show that the prototype fast neutron multiplicity counter design is very nearly optimized under the restraints of the parameter space.

  8. Adaptive hierarchical fuzzy controller

    SciTech Connect

    Raju, G.V.S.; Jun Zhou

    1993-07-01

    A methodology for designing adaptive hierarchical fuzzy controllers is presented. In order to evaluate this concept, several suitable performance indices were developed and converted to linguistic fuzzy variables. Based on those variables, a supervisory fuzzy rule set was constructed and used to change the parameters of a hierarchical fuzzy controller to accommodate the variations of system parameters. The proposed algorithm was used in feedwater flow control to a steam generator. Simulation studies are presented that illustrate the effectiveness of the approach

  9. Encoding olfactory signals via multiple chemosensory systems.

    PubMed

    Ma, Minghong

    2007-01-01

    Most animals have evolved multiple olfactory systems to detect general odors as well as social cues. The sophistication and interaction of these systems permit precise detection of food, danger, and mates, all crucial elements for survival. In most mammals, the nose contains two well described chemosensory apparatuses (the main olfactory epithelium and the vomeronasal organ), each of which comprises several subtypes of sensory neurons expressing distinct receptors and signal transduction machineries. In many species (e.g., rodents), the nasal cavity also includes two spatially segregated clusters of neurons forming the septal organ of Masera and the Grueneberg ganglion. Results of recent studies suggest that these chemosensory systems perceive diverse but overlapping olfactory cues and that some neurons may even detect the pressure changes carried by the airflow. This review provides an update on how chemosensory neurons transduce chemical (and possibly mechanical) stimuli into electrical signals, and what information each system brings into the brain. Future investigation will focus on the specific ligands that each system detects with a behavioral context and the processing networks that each system involves in the brain. Such studies will lead to a better understanding of how the multiple olfactory systems, acting in concert, offer a complete representation of the chemical world.

  10. A GIS-Enabled, Michigan-Specific, Hierarchical Groundwater Modeling and Visualization System

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Li, S.; Mandle, R.; Simard, A.; Fisher, B.; Brown, E.; Ross, S.

    2005-12-01

    Efficient management of groundwater resources relies on a comprehensive database that represents the characteristics of the natural groundwater system as well as analysis and modeling tools to describe the impacts of decision alternatives. Many agencies in Michigan have spent several years compiling expensive and comprehensive surface water and groundwater inventories and other related spatial data that describe their respective areas of responsibility. However, most often this wealth of descriptive data has only been utilized for basic mapping purposes. The benefits from analyzing these data, using GIS analysis functions or externally developed analysis models or programs, has yet to be systematically realized. In this talk, we present a comprehensive software environment that allows Michigan groundwater resources managers and frontline professionals to make more effective use of the available data and improve their ability to manage and protect groundwater resources, address potential conflicts, design cleanup schemes, and prioritize investigation activities. In particular, we take advantage of the Interactive Ground Water (IGW) modeling system and convert it to a customized software environment specifically for analyzing, modeling, and visualizing the Michigan statewide groundwater database. The resulting Michigan IGW modeling system (IGW-M) is completely window-based, fully interactive, and seamlessly integrated with a GIS mapping engine. The system operates in real-time (on the fly) providing dynamic, hierarchical mapping, modeling, spatial analysis, and visualization. Specifically, IGW-M allows water resources and environmental professionals in Michigan to: * Access and utilize the extensive data from the statewide groundwater database, interactively manipulate GIS objects, and display and query the associated data and attributes; * Analyze and model the statewide groundwater database, interactively convert GIS objects into numerical model features

  11. Orbital flips in hierarchical triple systems: Relativistic effects and third-body effects to hexadecapole order

    NASA Astrophysics Data System (ADS)

    Will, Clifford M.

    2017-07-01

    We analyze the secular evolution of hierarchical triple systems in the post-Newtonian approximation to general relativity. We expand the Newtonian three-body equations of motion in powers of the ratio a /A , where a and A are the semimajor axis of the inner binary's orbit and of the orbit of the third body relative to the center of mass of the inner binary, respectively. The leading order "quadrupole" terms, of order (a /A )3 relative to the 1 /a2 acceleration within the inner binary, are responsible for the well-known Kozai-Lidov oscillations of orbital inclination and eccentricity. The octupole terms, of order (a /A )4 have been shown to allow the inner orbit to "flip" from prograde relative to the outer orbit to retrograde and back, and to permit excursions to very large eccentricities. We carry the expansion of the equations of motion to hexadecapole order, corresponding to contributions of order (a /A )5. We also include the leading orbital effects of post-Newtonian theory, namely the pericenter precessions of the inner and outer orbits. Using the Lagrange planetary equations for the orbit elements of both binaries, we average over orbital time scales, obtain the equations for the secular evolution of the elements through hexadecapole order, and employ them to analyze cases of astrophysical interest. We find that, for the most part, the orbital flips found at octupole order are robust against both relativistic and hexadecapole perturbations. We show that, for equal-mass inner binaries, where the octupole terms vanish, the hexadecapole contributions can alone generate orbital flips and excursions to very large eccentricities.

  12. Hierarchical, parallel computing strategies using component object model for process modelling responses of forest plantations to interacting multiple stresses

    Treesearch

    J. G. Isebrands; G. E. Host; K. Lenz; G. Wu; H. W. Stech

    2000-01-01

    Process models are powerful research tools for assessing the effects of multiple environmental stresses on forest plantations. These models are driven by interacting environmental variables and often include genetic factors necessary for assessing forest plantation growth over a range of different site, climate, and silvicultural conditions. However, process models are...

  13. Controlled fabrication of SrMoO{sub 4} hierarchical nanosheets in a surfactant-assisted nonaqueous system

    SciTech Connect

    Lei, Shuijin; Peng, Xiaomin; Li, Xiuping; Liang, Zhihong; Yang, Yi; Cheng, Baochang; Xiao, Yanhe; Zhou, Lang

    2011-04-15

    Research highlights: {yields} An imitated nonaqueous microemulsion system was developed. {yields} Various hierarchical architectures of SrMoO{sub 4} nanosheets were fabricated. {yields} The solvent, surfactant, reaction temperature and reaction time were important. {yields} The products emit a strong blue (474 nm) and weak green (573 nm) luminescence. -- Abstract: Various hierarchical architectures of SrMoO{sub 4} nanosheets (thickness of 8-9 nm) have been successfully prepared in nonaqueous system by a surfactant-assisted solvothermal method. X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy were employed to study the crystal structure and morphologies of the products. Experiments showed that the solvent, surfactant, reaction temperature and reaction time were crucial for the oriented aggregation of the SrMoO{sub 4} nanosheets. Morphological control of these parameters resulted in platelet, column, interlaced multilayer and nest of nanosheets. A possible growth mechanism for these hierarchical architectures has also been proposed according to the morphological evolution with the reaction time. The optical properties of the products were also examined by means of photoluminescence and excitation spectroscopy. Photoluminescence studies revealed that these SrMoO{sub 4} nanocrystals exhibited a greatly strong blue emission under 325-nm excitation with different intensities but centered at the same position of 474 nm.

  14. The Hierarchical Ordering of Conceptual Systems in Biology: Problems of Student Teachers.

    ERIC Educational Resources Information Center

    Boschhuizen, Robert

    1988-01-01

    This article illustrates some problems faced by student teachers of biology when they try to realize the process of "didactic transformation" while planning their classes. To address these problems, a method of subject-matter analysis, utilizing hierarchical concept-maps, was introduced into the teacher training component at the Free…

  15. Evaluation of a hierarchical ascendant clustering process implemented in a veterinary syndromic surveillance system.

    PubMed

    Behaeghel, Isabelle; Veldhuis, Anouk; Ren, Libo; Méroc, Estelle; Koenen, Frank; Kerkhofs, Pierre; Van der Stede, Yves; Barnouin, Jacques; Dispas, Marc

    2015-06-15

    Syndromic surveillance is considered as one of the surveillance components for early warning of health-related events, as it allows detection of aberrations in health indicators before laboratory confirmation. "MoSS-Emergences 2" (MoSS-E2), a tool for veterinary syndromic surveillance, aggregates groups of similar clinical observations by hierarchical ascendant classification (HAC). In the present study, this HAC clustering process was evaluated using a reference set of data that, for the purpose of this evaluation, was a priori divided and defined as Bluetongue (BTV) positive cases (PC) on the one hand and BTV negative cases (NC) on the other hand. By comparing the clustering result of MoSS-E2 with the expected outcome, the sensitivity (the ability to cluster PC together) and specificity (the ability to exclude NC from PC) of the clustering process were determined for this set of data. The stability of the classes obtained with the clustering algorithm was evaluated by comparing the MoSS-E2 generated dendrogram (applying complete linkage) with dendrograms of STATA® software applying average and single linkage methods. To assess the systems' robustness, the parameters of the distance measure were adjusted according to different scenarios and obtained outcomes were compared to the expected outcome based on the a priori known labels. Rand indexes were calculated to measure similarity between clustering outcomes. The clustering algorithm in its default settings successfully segregated the reference BTV cases from the non-BTV cases, resulting in a sensitivity of 100.0% (95% CI: 89.0-100.0) and a specificity of 100.0% (95% CI: 80.0-100.0) for this set of data. The different linkage methods showed similar clustering results indicating stability of the classes (Rand indexes of respectively 0.77 for average and 0.75 for single linkage). The system proved to be robust when changing the parameters as the BTV cases remained together in meaningful clusters (Rand indexes

  16. Examining the Impact of Prior Models in Transmural Electrophysiological Imaging: A Hierarchical Multiple-Model Bayesian Approach

    PubMed Central

    Rahimi, Azar; Sapp, John; Xu, Jingjia; Bajorski, Peter; Horacek, Milan; Wang, Linwei

    2015-01-01

    Noninvasive cardiac electrophysiological (EP) imaging aims to mathematically reconstruct the spatiotemporal dynamics of cardiac sources from body-surface electrocardiographic (ECG) data. This ill-posed problem is often regularized by a fixed constraining model. However, a fixed-model approach enforces the source distribution to follow a pre-assumed structure that does not always match the varying spatiotemporal distribution of actual sources. To understand the model-data relation and examine the impact of prior models, we present a multiple-model approach for volumetric cardiac EP imaging where multiple prior models are included and automatically picked by the available ECG data. Multiple models are incorporated as an Lp-norm prior for sources, where p is an unknown hyperparameter with a prior uniform distribution. To examine how different combinations of models may be favored by different measurement data, the posterior distribution of cardiac sources and hyperparameter p is calculated using a Markov Chain Monte Carlo (MCMC) technique. The importance of multiple-model prior was assessed in two sets of synthetic and real-data experiments, compared to fixed-model priors (using Laplace and Gaussian priors). The results showed that the posterior combination of models (the posterior distribution of p) as determined by the ECG data differed substantially when reconstructing sources with different sizes and structures. While the use of fixed models is best suited in situations where the prior assumption fits the actual source structures, the use of an automatically adaptive set of models may have the ability to better address model-data mismatch and to provide consistent performance in reconstructing sources with different properties. PMID:26259018

  17. Examining the Impact of Prior Models in Transmural Electrophysiological Imaging: A Hierarchical Multiple-Model Bayesian Approach.

    PubMed

    Rahimi, Azar; Sapp, John; Xu, Jingjia; Bajorski, Peter; Horacek, Milan; Wang, Linwei

    2016-01-01

    Noninvasive cardiac electrophysiological (EP) imaging aims to mathematically reconstruct the spatiotemporal dynamics of cardiac sources from body-surface electrocardiographic (ECG) data. This ill-posed problem is often regularized by a fixed constraining model. However, a fixed-model approach enforces the source distribution to follow a pre-assumed structure that does not always match the varying spatiotemporal distribution of actual sources. To understand the model-data relation and examine the impact of prior models, we present a multiple-model approach for volumetric cardiac EP imaging where multiple prior models are included and automatically picked by the available ECG data. Multiple models are incorporated as an Lp-norm prior for sources, where p is an unknown hyperparameter with a prior uniform distribution. To examine how different combinations of models may be favored by different measurement data, the posterior distribution of cardiac sources and hyperparameter p is calculated using a Markov Chain Monte Carlo (MCMC) technique. The importance of multiple-model prior was assessed in two sets of synthetic and real-data experiments, compared to fixed-model priors (using Laplace and Gaussian priors). The results showed that the posterior combination of models (the posterior distribution of p) as determined by the ECG data differed substantially when reconstructing sources with different sizes and structures. While the use of fixed models is best suited in situations where the prior assumption fits the actual source structures, the use of an automatically adaptive set of models may have the ability to better address model-data mismatch and to provide consistent performance in reconstructing sources with different properties.

  18. Hierarchical Goal Analysis and Performance Modelling for the Control of Multiple UAVs/UCAVs from an Airborne Platform. Volume 1

    DTIC Science & Technology

    2007-11-02

    3.5 3.4.2 Normalized Data Plots ......................................................................................... 3.6 3.4.3 Summary of...The CFEC ALIX is intended to involve one Medium Altitude Long Endurance ( MALE ) UAV, multiple sensors, beyond line of sight communications via...satellite and an analysis of the integration issues associated with UAV operations. MALE UAV sorties will last approximately one day. This exercise

  19. Multiple energy synchrotron biomedical imaging system

    NASA Astrophysics Data System (ADS)

    Bassey, B.; Martinson, M.; Samadi, N.; Belev, G.; Karanfil, C.; Qi, P.; Chapman, D.

    2016-12-01

    A multiple energy imaging system that can extract multiple endogenous or induced contrast materials as well as water and bone images would be ideal for imaging of biological subjects. The continuous spectrum available from synchrotron light facilities provides a nearly perfect source for multiple energy x-ray imaging. A novel multiple energy x-ray imaging system, which prepares a horizontally focused polychromatic x-ray beam, has been developed at the BioMedical Imaging and Therapy bend magnet beamline at the Canadian Light Source. The imaging system is made up of a cylindrically bent Laue single silicon (5,1,1) crystal monochromator, scanning and positioning stages for the subjects, flat panel (area) detector, and a data acquisition and control system. Depending on the crystal’s bent radius, reflection type, and the horizontal beam width of the filtered synchrotron radiation (20-50 keV) used, the size and spectral energy range of the focused beam prepared varied. For example, with a bent radius of 95 cm, a (1,1,1) type reflection and a 50 mm wide beam, a 0.5 mm wide focused beam of spectral energy range 27 keV-43 keV was obtained. This spectral energy range covers the K-edges of iodine (33.17 keV), xenon (34.56 keV), cesium (35.99 keV), and barium (37.44 keV) some of these elements are used as biomedical and clinical contrast agents. Using the developed imaging system, a test subject composed of iodine, xenon, cesium, and barium along with water and bone were imaged and their projected concentrations successfully extracted. The estimated dose rate to test subjects imaged at a ring current of 200 mA is 8.7 mGy s-1, corresponding to a cumulative dose of 1.3 Gy and a dose of 26.1 mGy per image. Potential biomedical applications of the imaging system will include projection imaging that requires any of the extracted elements as a contrast agent and multi-contrast K-edge imaging.

  20. Iontophoretic Transport Across a Multiple Membrane System

    PubMed Central

    MOLOKHIA, SARAH A.; ZHANG, YANHUI; HIGUCHI, WILLIAM I.; LI, S. KEVIN

    2008-01-01

    The objective of the present study was to investigate the iontophoretic transport behavior across multiple membranes of different barrier properties. Spectra/Por® (SP) and Ionac membranes were the synthetic membranes and sclera was the biomembrane in this model study. The barrier properties of SP membranes were determined individually in passive and iontophoresis transport experiments with tetraethylammonium ion (TEA), chloride ion (Cl), and mannitol as the model permeants. Passive and iontophoretic transport experiments were then conducted with an assembly of SP membranes. The contribution of electroosmosis to iontophoresis was assessed using the mannitol data. Model analysis was performed to study the contribution of diffusion and electromigration to electrotransport across the multiple membrane system. The effects of membrane barrier thickness upon ion-exchange membrane-enhanced iontophoresis were examined with Ionac, SP, and sclera. The present study shows that iontophoretic transport of TEA across the membrane system was related to the thicknesses and permeability coefficients of the membranes and the electromobilities of the permeant across the individual membranes in the assembly. Model analysis suggests significant contribution of diffusion within the membranes across the membrane system, and this mechanism is relatively independent of the current density applied across the system in iontophoresis dominant transport. PMID:17990310

  1. HD 35502: a hierarchical triple system with a magnetic B5IVpe primary

    NASA Astrophysics Data System (ADS)

    Sikora, J.; Wade, G. A.; Bohlender, D. A.; Shultz, M.; Adelman, S. J.; Alecian, E.; Hanes, D.; Monin, D.; Neiner, C.; MiMeS Collaboration; BinaMIcS Collaboration

    2016-08-01

    We present our analysis of HD 35502 based on high- and medium-resolution spectropolarimetric observations. Our results indicate that the magnetic B5IVsnp star is the primary component of a spectroscopic triple system and that it has an effective temperature of 18.4 ± 0.6 kK, a mass of 5.7 ± 0.6 M⊙, and a polar radius of 3.0^{+1.1}_{-0.5} R_{odot }. The two secondary components are found to be essentially identical A-type stars for which we derive effective temperatures (8.9 ± 0.3 kK), masses (2.1 ± 0.2 M⊙), and radii (2.1 ± 0.4 R⊙). We infer a hierarchical orbital configuration for the system in which the secondary components form a tight binary with an orbital period of 5.668 66(6) d that orbits the primary component with a period of over 40 yr. Least-Squares Deconvolution profiles reveal Zeeman signatures in Stokes V indicative of a longitudinal magnetic field produced by the B star ranging from approximately -4 to 0 kG with a median uncertainty of 0.4 kG. These measurements, along with the line variability produced by strong emission in Hα, are used to derive a rotational period of 0.853 807(3) d. We find that the measured v sin i = 75 ± 5 km s-1 of the B star then implies an inclination angle of the star's rotation axis to the line of sight of 24^{+6}_{-10}{}^circ. Assuming the Oblique Rotator Model, we derive the magnetic field strength of the B star's dipolar component (14^{+9}_{-3} kG) and its obliquity (63± 13deg). Furthermore, we demonstrate that the calculated Alfvén radius (41^{+17}_{-6}R_ast) and Kepler radius (2.1^{+0.4}_{-0.7}R_ast) place HD 35502's central B star well within the regime of centrifugal magnetosphere-hosting stars.

  2. The labeled systems of multiple neural networks.

    PubMed

    Nemissi, M; Seridi, H; Akdag, H

    2008-08-01

    This paper proposes an implementation scheme of K-class classification problem using systems of multiple neural networks. Usually, a multi-class problem is decomposed into simple sub-problems solved independently using similar single neural networks. For the reason that these sub-problems are not equivalent in their complexity, we propose a system that includes reinforced networks destined to solve complicated parts of the entire problem. Our approach is inspired from principles of the multi-classifiers systems and the labeled classification, which aims to improve performances of the networks trained by the Back-Propagation algorithm. We propose two implementation schemes based on both OAO (one-against-all) and OAA (one-against-one). The proposed models are evaluated using iris and human thigh databases.

  3. Multiple weapon system distributed sensor concept

    NASA Astrophysics Data System (ADS)

    Rafailov, Michael K.

    2009-05-01

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

  4. [Susceptibility gene in multiple system atrophy (MSA)].

    PubMed

    Tsuji, Shoji

    2014-01-01

    To elucidate molecular bases of multiple system atrophy (MSA), we first focused on recently identified MSA multiplex families. Though linkage analyses followed by whole genome resequencing, we have identified a causative gene, COQ2, for MSA. We then conducted comprehensive nucleotide sequence analysis of COQ2 of sporadic MSA cases and controls, and found that functionally deleterious COQ2 variants confer a strong risk for developing MSA. COQ2 encodes an enzyme in the biosynthetic pathway of coenzyme Q10. Decreased synthesis of coenzyme Q10 is considered to be involved in the pathogenesis of MSA through decreased electron transport in mitochondria and increased vulnerability to oxidative stress.

  5. Performance of random multiple access transmission system

    NASA Technical Reports Server (NTRS)

    Phinainitisart, N.; Wu, W. W.

    1990-01-01

    The performance of the Random Multiple Access (RMA) technique, applied to a direct terminal-to-terminal link with a large number of potential users, is determined. The average signal-to-noise ratio (SNR) is derived. Under Gaussian assumption, the approximation of the probability of error is given. The analysis shows that the system performance is affected by the sequence length, the number of simultaneous users, and the number of cochannel symbols, but is not sensitive to the thermal noise. The performance of using very small aperture antenna for both transmitting and receiving without a hub station is given.

  6. Multiple System Atrophy: Genetic or Epigenetic?

    PubMed Central

    Sturm, Edith

    2014-01-01

    Multiple system atrophy (MSA) is a rare, late-onset and fatal neurodegenerative disease including multisystem neurodegeneration and the formation of α-synuclein containing oligodendroglial cytoplasmic inclusions (GCIs), which present the hallmark of the disease. MSA is considered to be a sporadic disease; however certain genetic aspects have been studied during the last years in order to shed light on the largely unknown etiology and pathogenesis of the disease. Epidemiological studies focused on the possible impact of environmental factors on MSA disease development. This article gives an overview on the findings from genetic and epigenetic studies on MSA and discusses the role of genetic or epigenetic factors in disease pathogenesis. PMID:25548529

  7. Hierarchical functional connectivity between the core language system and the working memory system.

    PubMed

    Makuuchi, Michiru; Friederici, Angela D

    2013-10-01

    Language processing inevitably involves working memory (WM) operations, especially for sentences with complex syntactic structures. Evidence has been provided for a neuroanatomical segregation between core syntactic processes and WM, but the dynamic relation between these systems still has to be explored. In the present functional magnetic resonance imaging (fMRI) study, we investigated the network dynamics of regions involved in WM operations which support sentence processing during reading, comparing a set of dynamic causal models (DCM) with different assumptions about the underlying connectional architecture. The DCMs incorporated the core language processing regions (pars opercularis and middle temporal gyrus), WM related regions (inferior frontal sulcus and intraparietal sulcus), and visual word form area (fusiform gyrus). The results indicate a processing hierarchy from the visual to WM to core language systems, and moreover, a clear increase of connectivity between WM regions and language regions as the processing load increases for syntactically complex sentences. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Distributed functions of detection and discrimination of vibrotactile stimuli in the hierarchical human somatosensory system

    PubMed Central

    Kim, Junsuk; Müller, Klaus-Robert; Chung, Yoon Gi; Chung, Soon-Cheol; Park, Jang-Yeon; Bülthoff, Heinrich H.; Kim, Sung-Phil

    2015-01-01

    According to the hierarchical view of human somatosensory network, somatic sensory information is relayed from the thalamus to primary somatosensory cortex (S1), and then distributed to adjacent cortical regions to perform further perceptual and cognitive functions. Although a number of neuroimaging studies have examined neuronal activity correlated with tactile stimuli, comparatively less attention has been devoted toward understanding how vibrotactile stimulus information is processed in the hierarchical somatosensory cortical network. To explore the hierarchical perspective of tactile information processing, we studied two cases: (a) discrimination between the locations of finger stimulation; and (b) detection of stimulation against no stimulation on individual fingers, using both standard general linear model (GLM) and searchlight multi-voxel pattern analysis (MVPA) techniques. These two cases were studied on the same data set resulting from a passive vibrotactile stimulation experiment. Our results showed that vibrotactile stimulus locations on fingers could be discriminated from measurements of human functional magnetic resonance imaging (fMRI). In particular, it was in case (a) we observed activity in contralateral posterior parietal cortex (PPC) and supramarginal gyrus (SMG) but not in S1, while in case; (b) we found significant cortical activations in S1 but not in PPC and SMG. These discrepant observations suggest the functional specialization with regard to vibrotactile stimulus locations, especially, the hierarchical information processing in the human somatosensory cortical areas. Our findings moreover support the general understanding that S1 is the main sensory receptive area for the sense of touch, and adjacent cortical regions (i.e., PPC and SMG) are in charge of a higher level of processing and may thus contribute most for the successful classification between stimulated finger locations. PMID:25653609

  9. The Design and Analysis of a Complete Hierarchical Interface for the Multi-Backend Database System.

    DTIC Science & Technology

    1984-06-01

    translates Data Language/One (DL/I) calls into attribute-based data language ( ABDL ) requests. We describe the data structures, the control structures, and...DL/I) calls into attribute- based data language ( ABDL ) requests. We - t the data structures, the control structures, and the functions required to...15 3. The Attribute-Based Data Language ( ABDL ) ...................... 19 B. THE HIERARCHICAL DATA MODEL ............ 20 1. A

  10. Distributed functions of detection and discrimination of vibrotactile stimuli in the hierarchical human somatosensory system.

    PubMed

    Kim, Junsuk; Müller, Klaus-Robert; Chung, Yoon Gi; Chung, Soon-Cheol; Park, Jang-Yeon; Bülthoff, Heinrich H; Kim, Sung-Phil

    2014-01-01

    According to the hierarchical view of human somatosensory network, somatic sensory information is relayed from the thalamus to primary somatosensory cortex (S1), and then distributed to adjacent cortical regions to perform further perceptual and cognitive functions. Although a number of neuroimaging studies have examined neuronal activity correlated with tactile stimuli, comparatively less attention has been devoted toward understanding how vibrotactile stimulus information is processed in the hierarchical somatosensory cortical network. To explore the hierarchical perspective of tactile information processing, we studied two cases: (a) discrimination between the locations of finger stimulation; and (b) detection of stimulation against no stimulation on individual fingers, using both standard general linear model (GLM) and searchlight multi-voxel pattern analysis (MVPA) techniques. These two cases were studied on the same data set resulting from a passive vibrotactile stimulation experiment. Our results showed that vibrotactile stimulus locations on fingers could be discriminated from measurements of human functional magnetic resonance imaging (fMRI). In particular, it was in case (a) we observed activity in contralateral posterior parietal cortex (PPC) and supramarginal gyrus (SMG) but not in S1, while in case; (b) we found significant cortical activations in S1 but not in PPC and SMG. These discrepant observations suggest the functional specialization with regard to vibrotactile stimulus locations, especially, the hierarchical information processing in the human somatosensory cortical areas. Our findings moreover support the general understanding that S1 is the main sensory receptive area for the sense of touch, and adjacent cortical regions (i.e., PPC and SMG) are in charge of a higher level of processing and may thus contribute most for the successful classification between stimulated finger locations.

  11. In vitro models of multiple system atrophy.

    PubMed

    Stefanova, Nadia; Reindl, Markus; Poewe, Werner; Wenning, Gregor K

    2005-08-01

    alpha-Synuclein represents the major constituent of oligodendroglial cytoplasmic inclusions, the hallmark lesion of multiple system atrophy (MSA), a progressive disorder that is associated with selective degenerative cell loss in basal ganglia, cerebellum, brainstem, and spinal cord. The role of abnormal alpha-synuclein aggregation in oligodendroglial cells is still obscure, in particular, whether alpha-synuclein might impair oligodendroglial and, secondarily, neuronal integrity of those cells in the diseased brain. In an attempt to answer some of these questions, we have developed an "in vitro model of MSA" by expressing the wild-type or C-terminally truncated form of alpha-synuclein in glial cell cultures. With this simplified system, we have demonstrated that alpha-synuclein significantly affects the survival of glia and its vulnerability to environmental stress, which might represent a major step in the pathogenesis of MSA.

  12. Multiple beam antenna/switch system study

    NASA Technical Reports Server (NTRS)

    1989-01-01

    In the study of the Multiple Beam Antenna/Switch for the space to ground link (SGL) uplink and downlink services, several issues related to system engineering, antenna, transmit/receive, and switch systems were addressed and the results are provided. Bandwidth allocation at Ku band is inadequate to serve the data rate requirements for the forward and return services. Rain and depolarization effects at EHF, especially at Ka band, pose a significant threat to the link availabilities at heavy rain areas. Hardware induced effects such as the nonlinear characteristics of the power amplifier may necessitate the use of linearizers and limiters. It is also important to identify the components that are susceptible to the space radiation effects and shield or redesign them with rad-hard technologies for meeting the requirements of the space environment.

  13. Multiple channel optical data acquisition system

    DOEpatents

    Fasching, G.E.; Goff, D.R.

    1985-02-22

    A multiple channel optical data acquisition system is provided in which a plurality of remote sensors monitoring specific process variable are interrogated by means of a single optical fiber connecting the remote station/sensors to a base station. The remote station/sensors derive all power from light transmitted through the fiber from the base station. Each station/sensor is individually accessed by means of a light modulated address code sent over the fiber. The remote station/sensors use a single light emitting diode to both send and receive light signals to communicate with the base station and provide power for the remote station. The system described can power at least 100 remote station/sensors over an optical fiber one mile in length.

  14. Image Information Mining Utilizing Hierarchical Segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James C.; Marchisio, Giovanni; Koperski, Krzysztof; Datcu, Mihai

    2002-01-01

    The Hierarchical Segmentation (HSEG) algorithm is an approach for producing high quality, hierarchically related image segmentations. The VisiMine image information mining system utilizes clustering and segmentation algorithms for reducing visual information in multispectral images to a manageable size. The project discussed herein seeks to enhance the VisiMine system through incorporating hierarchical segmentations from HSEG into the VisiMine system.

  15. Contour detection and hierarchical image segmentation.

    PubMed

    Arbeláez, Pablo; Maire, Michael; Fowlkes, Charless; Malik, Jitendra

    2011-05-01

    This paper investigates two fundamental problems in computer vision: contour detection and image segmentation. We present state-of-the-art algorithms for both of these tasks. Our contour detector combines multiple local cues into a globalization framework based on spectral clustering. Our segmentation algorithm consists of generic machinery for transforming the output of any contour detector into a hierarchical region tree. In this manner, we reduce the problem of image segmentation to that of contour detection. Extensive experimental evaluation demonstrates that both our contour detection and segmentation methods significantly outperform competing algorithms. The automatically generated hierarchical segmentations can be interactively refined by user-specified annotations. Computation at multiple image resolutions provides a means of coupling our system to recognition applications.

  16. Multiple beam laser cell micropatterning system

    NASA Astrophysics Data System (ADS)

    Narasimhan, Sriram V.; Goodwin, Richard L.; Borg, Thomas K.; Dawson, Darren M.; Gao, Bruce Z.

    2004-10-01

    The various cell mechanisms, including cell-cell interactions, in native tissue could be better understood by engineering a cell coculture with a micro environment that closely mimics the natural cell arrangement. To this end, we developed a cell micropatterning system that uses a weakly focused laser beam to trap individual cells at the center of the beam and propel them forward onto an appropriate substrate. The optimal methods of introducing different cell types to be patterned into the patterning system and preventing cells from randomly falling onto the pattern were issues to be addressed with this system. Here, we report the development of a multi-chamber, multi-beam laser cell micropatterning system, in which the delivery of specific cells into the beam can be controlled using secondary laser beams. This permits consecutive creation of a pattern involving multiple cell types at specific relative positions. As examples, various patterns of fibroblasts have been created on collagen coated coverslips. In addition, two asynchronously beating clusters of cardiomyocytes were connected with fibroblasts of cardiac origin, yielding a deeper insight into the electrophysiological role of fibroblasts in conduction of the action potentials among cardiomyocytes.

  17. Resilient model approximation for Markov jump time-delay systems via reduced model with hierarchical Markov chains

    NASA Astrophysics Data System (ADS)

    Zhu, Yanzheng; Zhang, Lixian; Sreeram, Victor; Shammakh, Wafa; Ahmad, Bashir

    2016-10-01

    In this paper, the resilient model approximation problem for a class of discrete-time Markov jump time-delay systems with input sector-bounded nonlinearities is investigated. A linearised reduced-order model is determined with mode changes subject to domination by a hierarchical Markov chain containing two different nonhomogeneous Markov chains. Hence, the reduced-order model obtained not only reflects the dependence of the original systems but also model external influence that is related to the mode changes of the original system. Sufficient conditions formulated in terms of bilinear matrix inequalities for the existence of such models are established, such that the resulting error system is stochastically stable and has a guaranteed l2-l∞ error performance. A linear matrix inequalities optimisation coupled with line search is exploited to solve for the corresponding reduced-order systems. The potential and effectiveness of the developed theoretical results are demonstrated via a numerical example.

  18. MPACT Fast Neutron Multiplicity System Design Concepts

    SciTech Connect

    D. L. Chichester; S. A. Pozzi; J. L. Dolan; M. T. Kinlaw; A. C. Kaplan; M. Flaska; A. Enqvist; J. T. Johnsom; S. M. Watson

    2012-10-01

    This report documents work performed by Idaho National Laboratory and the University of Michigan in fiscal year (FY) 2012 to examine design parameters related to the use of fast-neutron multiplicity counting for assaying plutonium for materials protection, accountancy, and control purposes. This project seeks to develop a new type of neutron-measurement-based plutonium assay instrument suited for assaying advanced fuel cycle materials. Some current-concept advanced fuels contain high concentrations of plutonium; some of these concept fuels also contain other fissionable actinides besides plutonium. Because of these attributes the neutron emission rates of these new fuels may be much higher, and more difficult to interpret, than measurements made of plutonium-only materials. Fast neutron multiplicity analysis is one approach for assaying these advanced nuclear fuels. Studies have been performed to assess the conceptual performance capabilities of a fast-neutron multiplicity counter for assaying plutonium. Comparisons have been made to evaluate the potential improvements and benefits of fast-neutron multiplicity analyses versus traditional thermal-neutron counting systems. Fast-neutron instrumentation, using for example an array of liquid scintillators such as EJ-309, have the potential to either a) significantly reduce assay measurement times versus traditional approaches, for comparable measurement precision values, b) significantly improve assay precision values, for measurement durations comparable to current-generation technology, or c) moderating improve both measurement precision and measurement durations versus current-generation technology. Using the MCNPX-PoliMi Monte Carlo simulation code, studies have been performed to assess the doubles-detection efficiency for a variety of counter layouts of cylindrical liquid scintillator detector cells over one, two, and three rows. Ignoring other considerations, the best detector design is the one with the most

  19. Adaptive Hierarchical Sliding Mode Control with Input Saturation for Attitude Regulation of Multi-satellite Tethered System

    NASA Astrophysics Data System (ADS)

    Ma, Zhiqiang; Sun, Guanghui

    2017-06-01

    This paper proposes a novel adaptive hierarchical sliding mode control for the attitude regulation of the multi-satellite inline tethered system, where the input saturation is taken into account. The governing equations for the attitude dynamics of the three-satellite inline tethered system are derived firstly by utilizing Lagrangian mechanics theory. Considering the fact that the attitude of the central satellite can be adjusted by using the simple exponential stabilization scheme, the decoupling of the central satellite and the terminal ones is presented, and in addition, the new adaptive sliding mode control law is applied to stabilize the attitude dynamics of the two terminal satellites based on the synchronization and partial contraction theory. In the adaptive hierarchical sliding mode control design, the input is modeled as saturated input due to the fact that the flywheel torque is bounded, and meanwhile, an adaptive update rate is introduced to eliminate the effect of the saturated input and the external perturbation. The proposed control scheme can be applied on the two-satellite system to achieve fixed-point rotation. Numerical results validate the effectiveness of the proposed method.

  20. Adaptive Hierarchical Sliding Mode Control with Input Saturation for Attitude Regulation of Multi-satellite Tethered System

    NASA Astrophysics Data System (ADS)

    Ma, Zhiqiang; Sun, Guanghui

    2016-11-01

    This paper proposes a novel adaptive hierarchical sliding mode control for the attitude regulation of the multi-satellite inline tethered system, where the input saturation is taken into account. The governing equations for the attitude dynamics of the three-satellite inline tethered system are derived firstly by utilizing Lagrangian mechanics theory. Considering the fact that the attitude of the central satellite can be adjusted by using the simple exponential stabilization scheme, the decoupling of the central satellite and the terminal ones is presented, and in addition, the new adaptive sliding mode control law is applied to stabilize the attitude dynamics of the two terminal satellites based on the synchronization and partial contraction theory. In the adaptive hierarchical sliding mode control design, the input is modeled as saturated input due to the fact that the flywheel torque is bounded, and meanwhile, an adaptive update rate is introduced to eliminate the effect of the saturated input and the external perturbation. The proposed control scheme can be applied on the two-satellite system to achieve fixed-point rotation. Numerical results validate the effectiveness of the proposed method.

  1. Modeling, Simulation and Performance Analysis of Multiple-Input Multiple-Output (MIMO) Systems with Multicarrier Time Delay Diversity Modulation

    DTIC Science & Technology

    2005-09-01

    MULTIPLE - INPUT MULTIPLE - OUTPUT ( MIMO ) SYSTEMS WITH MULTICARRIER TIME DELAY DIVERSITY MODULATION by Muhammad...SUBTITLE: Modeling, Simulation and Performance Analysis of Multiple - Input Multiple - Output ( MIMO ) Systems with Multicarrier Time Delay Diversity Modulation...MISO) and multiple - input multiple - output ( MIMO ) radio communication systems with space-time codes. A MISO system and MIMO

  2. Hierarchical control of ride height system for electronically controlled air suspension based on variable structure and fuzzy control theory

    NASA Astrophysics Data System (ADS)

    Xu, Xing; Zhou, Kongkang; Zou, Nannan; Jiang, Hong; Cui, Xiaoli

    2015-09-01

    The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension (ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control (VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15°. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system.

  3. Parallel hierarchical radiosity rendering

    SciTech Connect

    Carter, Michael

    1993-07-01

    In this dissertation, the step-by-step development of a scalable parallel hierarchical radiosity renderer is documented. First, a new look is taken at the traditional radiosity equation, and a new form is presented in which the matrix of linear system coefficients is transformed into a symmetric matrix, thereby simplifying the problem and enabling a new solution technique to be applied. Next, the state-of-the-art hierarchical radiosity methods are examined for their suitability to parallel implementation, and scalability. Significant enhancements are also discovered which both improve their theoretical foundations and improve the images they generate. The resultant hierarchical radiosity algorithm is then examined for sources of parallelism, and for an architectural mapping. Several architectural mappings are discussed. A few key algorithmic changes are suggested during the process of making the algorithm parallel. Next, the performance, efficiency, and scalability of the algorithm are analyzed. The dissertation closes with a discussion of several ideas which have the potential to further enhance the hierarchical radiosity method, or provide an entirely new forum for the application of hierarchical methods.

  4. Quantized levitation states of superconducting multiple-ring systems

    SciTech Connect

    Haley, S.B.; Fink, H.J.

    1996-02-01

    The quantized levitation, trapped, and suspension states of a magnetic microsphere held in equilibrium by two fixed superconducting (SC) microrings are calculated by minimizing the free energy of the system. Each state is a discrete function of two independent fluxoid quantum numbers of the rings. When the radii of the SC rings are of the same order as the Ginzburg-Landau coherence length {xi}({ital T}), the system exhibits a small set of gravity and temperature-dependent levels. The levels of a weakly magnetized particle are sensitive functions of the gravitational field, indicating potential application as an accelerometer, and for trapping small magnetic particles in outer space or on Earth. The equilibrium states of a SC ring levitated by another SC ring are also calculated. {copyright} {ital 1996 The American Physical Society.}

  5. ξTauri: a unique laboratory to study the dynamic interaction in a compact hierarchical quadruple system

    NASA Astrophysics Data System (ADS)

    Nemravová, J. A.; Harmanec, P.; Brož, M.; Vokrouhlický, D.; Mourard, D.; Hummel, C. A.; Cameron, C.; Matthews, J. M.; Bolton, C. T.; Božić, H.; Chini, R.; Dembsky, T.; Engle, S.; Farrington, C.; Grunhut, J. H.; Guenther, D. B.; Guinan, E. F.; Korčáková, D.; Koubský, P.; Kříček, R.; Kuschnig, R.; Mayer, P.; McCook, G. P.; Moffat, A. F. J.; Nardetto, N.; Prša, A.; Ribeiro, J.; Rowe, J.; Rucinski, S.; Škoda, P.; Šlechta, M.; Tallon-Bosc, I.; Votruba, V.; Weiss, W. W.; Wolf, M.; Zasche, P.; Zavala, R. T.

    2016-10-01

    Context. Compact hierarchical systems are important because the effects caused by the dynamical interaction among its members occur ona human timescale. These interactions play a role in the formation of close binaries through Kozai cycles with tides. One such system is ξ Tauri: it has three hierarchical orbits: 7.14 d (eclipsing components Aa, Ab), 145 d (components Aa+Ab, B), and 51 yr (components Aa+Ab+B, C). Aims: We aim to obtain physical properties of the system and to study the dynamical interaction between its components. Methods: Our analysis is based on a large series of spectroscopic photometric (including space-borne) observations and long-baseline optical and infrared spectro-interferometric observations. We used two approaches to infer the system properties: a set of observation-specific models, where all components have elliptical trajectories, and an N-body model, which computes the trajectory of each component by integrating Newton's equations of motion. Results: The triple subsystem exhibits clear signs of dynamical interaction. The most pronounced are the advance of the apsidal line and eclipse-timing variations. We determined the geometry of all three orbits using both observation-specific and N-body models. The latter correctly accounted for observed effects of the dynamical interaction, predicted cyclic variations of orbital inclinations, and determined the sense of motion of all orbits. Using perturbation theory, we demonstrate that prominent secular and periodic dynamical effects are explainable with a quadrupole interaction. We constrained the basic properties of all components, especially of members of the inner triple subsystem and detected rapid low-amplitude light variations that we attribute to co-rotating surface structures of component B. We also estimated the radius of component B. Properties of component C remain uncertain because of its low relative luminosity. We provide an independent estimate of the distance to the system

  6. Probabilistic deployment for multiple sensor systems

    NASA Astrophysics Data System (ADS)

    Qian, Ming; Ferrari, Silvia

    2005-05-01

    The performance of many multi-sensor systems can be significantly improved by using a priori environmental information and sensor data to plan the movements of sensor platforms that are later deployed with the purpose of improving the quality of the final detection and classification results. However, existing path planning algorithms and ad-hoc data processing (e.g., fusion) techniques do not allow for the systematic treatment of multiple and heterogeneous sensors and their platforms. This paper presents a method that combines Bayesian network inference with probabilistic roadmap (PRM) planners to utilize the information obtained by different sensors and their level of uncertainty. The uncertainty of prior sensed information is represented by entropy values obtained from the Bayesian network (BN) models of the respective sensor measurement processes. The PRM algorithm is modified to utilize the entropy distribution in optimizing the path of posterior sensor platforms that have the following objectives: (1) improve the quality of the sensed information, i.e., through fusion, (2) minimize the distance traveled by the platforms, and (3) avoid obstacles. This so-called Probabilistic Deployment (PD) method is applied to a demining system comprised of ground-penetrating radars (GPR), electromagnetic (EMI), and infrared sensors (IR) installed on ground platforms, to detect and classify buried mines. Numerical simulations show that PD is more efficient than path planning techniques that do not utilize a priori information, such as complete coverage, random coverage method, or PRM methods that do not utilize Bayesian inference.

  7. Fluctuation relations between hierarchical kinetically equivalent networks with Arrhenius-type transitions and their roles in systems and structural biology

    NASA Astrophysics Data System (ADS)

    Deng, De-Ming; Lu, Yi-Ta; Chang, Cheng-Hung

    2017-06-01

    The legality of using simple kinetic schemes to determine the stochastic properties of a complex system depends on whether the fluctuations generated from hierarchical equivalent schemes are consistent with one another. To analyze this consistency, we perform lumping processes on the stochastic differential equations and the generalized fluctuation-dissipation theorem and apply them to networks with the frequently encountered Arrhenius-type transition rates. The explicit Langevin force derived from those networks enables us to calculate the state fluctuations caused by the intrinsic and extrinsic noises on the free energy surface and deduce their relations between kinetically equivalent networks. In addition to its applicability to wide classes of network related systems, such as those in structural and systems biology, the result sheds light on the fluctuation relations for general physical variables in Keizer's canonical theory.

  8. Fluctuation relations between hierarchical kinetically equivalent networks with Arrhenius-type transitions and their roles in systems and structural biology.

    PubMed

    Deng, De-Ming; Lu, Yi-Ta; Chang, Cheng-Hung

    2017-06-01

    The legality of using simple kinetic schemes to determine the stochastic properties of a complex system depends on whether the fluctuations generated from hierarchical equivalent schemes are consistent with one another. To analyze this consistency, we perform lumping processes on the stochastic differential equations and the generalized fluctuation-dissipation theorem and apply them to networks with the frequently encountered Arrhenius-type transition rates. The explicit Langevin force derived from those networks enables us to calculate the state fluctuations caused by the intrinsic and extrinsic noises on the free energy surface and deduce their relations between kinetically equivalent networks. In addition to its applicability to wide classes of network related systems, such as those in structural and systems biology, the result sheds light on the fluctuation relations for general physical variables in Keizer's canonical theory.

  9. A Decentralized Approach to the Formulation of Hypotheses: A Hierarchical Structural Model for a Prion Self-Assembled System

    NASA Astrophysics Data System (ADS)

    Wang, Mingyang; Zhang, Feifei; Song, Chao; Shi, Pengfei; Zhu, Jin

    2016-07-01

    Innovation in hypotheses is a key transformative driver for scientific development. The conventional centralized hypothesis formulation approach, where a dominant hypothesis is typically derived from a primary phenomenon, can, inevitably, impose restriction on the range of conceivable experiments and legitimate hypotheses, and ultimately impede understanding of the system of interest. We report herein the proposal of a decentralized approach for the formulation of hypotheses, through initial preconception-free phenomenon accumulation and subsequent reticular logical reasoning processes. The two-step approach can provide an unbiased, panoramic view of the system and as such should enable the generation of a set of more coherent and therefore plausible hypotheses. As a proof-of-concept demonstration of the utility of this open-ended approach, a hierarchical model has been developed for a prion self-assembled system, allowing insight into hitherto elusive static and dynamic features associated with this intriguing structure.

  10. Padé spectrum decompositions of quantum distribution functions and optimal hierarchical equations of motion construction for quantum open systems

    NASA Astrophysics Data System (ADS)

    Hu, Jie; Luo, Meng; Jiang, Feng; Xu, Rui-Xue; Yan, YiJing

    2011-06-01

    Padé spectrum decomposition is an optimal sum-over-poles expansion scheme of Fermi function and Bose function [J. Hu, R. X. Xu, and Y. J. Yan, J. Chem. Phys. 133, 101106 (2010)], 10.1063/1.3484491. In this work, we report two additional members to this family, from which the best among all sum-over-poles methods could be chosen for different cases of application. Methods are developed for determining these three Padé spectrum decomposition expansions at machine precision via simple algorithms. We exemplify the applications of present development with optimal construction of hierarchical equations-of-motion formulations for nonperturbative quantum dissipation and quantum transport dynamics. Numerical demonstrations are given for two systems. One is the transient transport current to an interacting quantum-dots system, together with the involved high-order co-tunneling dynamics. Another is the non-Markovian dynamics of a spin-boson system.

  11. A Decentralized Approach to the Formulation of Hypotheses: A Hierarchical Structural Model for a Prion Self-Assembled System

    PubMed Central

    Wang, Mingyang; Zhang, Feifei; Song, Chao; Shi, Pengfei; Zhu, Jin

    2016-01-01

    Innovation in hypotheses is a key transformative driver for scientific development. The conventional centralized hypothesis formulation approach, where a dominant hypothesis is typically derived from a primary phenomenon, can, inevitably, impose restriction on the range of conceivable experiments and legitimate hypotheses, and ultimately impede understanding of the system of interest. We report herein the proposal of a decentralized approach for the formulation of hypotheses, through initial preconception-free phenomenon accumulation and subsequent reticular logical reasoning processes. The two-step approach can provide an unbiased, panoramic view of the system and as such should enable the generation of a set of more coherent and therefore plausible hypotheses. As a proof-of-concept demonstration of the utility of this open-ended approach, a hierarchical model has been developed for a prion self-assembled system, allowing insight into hitherto elusive static and dynamic features associated with this intriguing structure. PMID:27464832

  12. Padé spectrum decompositions of quantum distribution functions and optimal hierarchical equations of motion construction for quantum open systems.

    PubMed

    Hu, Jie; Luo, Meng; Jiang, Feng; Xu, Rui-Xue; Yan, Yijing

    2011-06-28

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

  13. Method of forecasting energy center positions of laser beam spot images using a parallel hierarchical network for optical communication systems

    NASA Astrophysics Data System (ADS)

    Timchenko, Leonid I.; Kokryatskaya, Natalia I.; Melnikov, Viktor V.; Kosenko, Galina L.

    2013-05-01

    A forecasting method, based on the parallel-hierarchical (PH) network and hyperbolic smoothing of empirical data, is presented in this paper. Preceding values of the time series, hyperbolic smoothing, and PH network data are used for forecasting. To determine a position of the next route fragment in relation to X and Y axes, hyperbola parameters are sent to the route parameter forecasting system. In the results synchronization block, network-processed data arrive to the database where a sample of most correlated data is drawn using service parameters of the PH network. An average prediction error is 0.55% for the developed method and 1.62% for neural networks. That is why, due to the use of the PH network and hyperbolic smoothing, the developed method is more efficient for real-time systems than traditional neural networks in forecasting energy center positions of laser beam spot images for optical communication systems.

  14. Microparticles with hierarchical porosity

    DOEpatents

    Petsev, Dimiter N; Atanassov, Plamen; Pylypenko, Svitlana; Carroll, Nick; Olson, Tim

    2012-12-18

    The present disclosure provides oxide microparticles with engineered hierarchical porosity and methods of manufacturing the same. Also described are structures that are formed by templating, impregnating, and/or precipitating the oxide microparticles and method for forming the same. Suitable applications include catalysts, electrocatalysts, electrocatalysts support materials, capacitors, drug delivery systems, sensors and chromatography.

  15. Simulation of disaster recovery of a picture archiving and communications system using off-site hierarchal storage management.

    PubMed

    Avrin, D E; Andriole, K P; Yin, L; Gould, R; Arenson, R L

    2000-05-01

    The purpose of this communication is to report on the testing of the disaster recovery capability of our hierarchical storage management (HSM) system. Disaster recovery implementation is a requirement of every mission-critical information technology project. Picture archiving and communications systems (PACS) certainly falls into this category, even though the counterpart, conventional film archive, has no protection against fire, for example. We have implemented a method for hierarchical storage with wavelet technology that maximizes on-site case storage (using lossy compression), retains bit-preserved image data for legal purposes, provides an off-site backup (lossless bit-preserving wavelet transform), and provides for disaster recovery. Recovery from a natural (earthquake and subsequent fire) or technical (system crash and data loss) disaster was simulated by attempting to restore from the off-site image and database backup to clean core PACS components. The only existing loaded software was the operating system. The database application was reloaded locally, and then the database contents and image store were loaded from the off-site component of the HSM system. The following measurements were analyzed: (1) the ability to recover all data; (2) the integrity of the recovered database and image data; (3) the time to recover the database relative to the number of studies and age of the archive, as well as bandwidth between the local and remote site; and (4) the time to recover image data relative to compression ratio, number of studies, number of images, and time depth of the archive. This HSM system, which maximizes on-site storage, maintains a legal record, and provides off-site backup, also facilitates disaster recovery for a PACS.

  16. Common oscillatory mechanisms across multiple memory systems

    NASA Astrophysics Data System (ADS)

    Headley, Drew B.; Paré, Denis

    2017-01-01

    The cortex, hippocampus, and striatum support dissociable forms of memory. While each of these regions contains specialized circuitry supporting their respective functions, all structure their activities across time with delta, theta, and gamma rhythms. We review how these oscillations are generated and how they coordinate distinct memory systems during encoding, consolidation, and retrieval. First, gamma oscillations occur in all regions and coordinate local spiking, compressing it into short population bursts. Second, gamma oscillations are modulated by delta and theta oscillations. Third, oscillatory dynamics in these memory systems can operate in either a "slow" or "fast" mode. The slow mode happens during slow-wave sleep and is characterized by large irregular activity in the hippocampus and delta oscillations in cortical and striatal circuits. The fast mode occurs during active waking and rapid eye movement (REM) sleep and is characterized by theta oscillations in the hippocampus and its targets, along with gamma oscillations in the rest of cortex. In waking, the fast mode is associated with the efficacious encoding and retrieval of declarative and procedural memories. Theta and gamma oscillations have similar relationships with encoding and retrieval across multiple forms of memory and brain regions, despite regional differences in microcircuitry and information content. Differences in the oscillatory coordination of memory systems during sleep might explain why the consolidation of some forms of memory is sensitive to slow-wave sleep, while others depend on REM. In particular, theta oscillations appear to support the consolidation of certain types of procedural memories during REM, while delta oscillations during slow-wave sleep seem to promote declarative and procedural memories.

  17. Hierarchical Assembly of a Dual-responsive Macroscopic Insulated Molecular Wire Bundle in a Gradient System

    PubMed Central

    Sheng, Yujie; Chen, Qibin; Yao, Junyao; Wang, Ying; Liu, Honglai

    2015-01-01

    Here, we report the hierarchical self-assembly of a cationic gemini amphiphile, Azo 1, in a composition gradient solution generated using solvent evaporation. As the gradient solution is formed, Azo 1 forms nanorods in the lower region of the solution. Depending on solvent composition, these nanorods can further develop into nanofibres, which can then intertwine to form double helices and other types of nanohelices in the upper region of the solution. Finally, a macroscopic wire bundle is formed via the fusion of nanohelices; this ribbon-like bundle exhibits elasticity and linear ohmic resistance properties. More intriguingly, this bundle exhibits photoresponsive properties that affect its deformation and conductivity, as well as a rapid electroresponse that affects its conductivity, indicating that it is feasible to control the charge pathway. PMID:25588881

  18. The Challenge of Multiple Perspectives: Multiple Solution Tasks for Students Incorporating Diverse Tools and Representation Systems

    ERIC Educational Resources Information Center

    Kordaki, Maria

    2015-01-01

    This study focuses on the role of multiple solution tasks (MST) incorporating multiple learning tools and representation systems (MTRS) in encouraging each student to develop multiple perspectives on the learning concepts under study and creativity of thought. Specifically, two types of MST were used, namely tasks that allowed and demanded…

  19. The Challenge of Multiple Perspectives: Multiple Solution Tasks for Students Incorporating Diverse Tools and Representation Systems

    ERIC Educational Resources Information Center

    Kordaki, Maria

    2015-01-01

    This study focuses on the role of multiple solution tasks (MST) incorporating multiple learning tools and representation systems (MTRS) in encouraging each student to develop multiple perspectives on the learning concepts under study and creativity of thought. Specifically, two types of MST were used, namely tasks that allowed and demanded…

  20. Dynamical modelling of coordinated multiple robot systems

    NASA Technical Reports Server (NTRS)

    Hayati, Samad

    1987-01-01

    The state of the art in the modeling of the dynamics of coordinated multiple robot manipulators is summarized and various problems related to this subject are discussed. It is recognized that dynamics modeling is a component used in the design of controllers for multiple cooperating robots. As such, the discussion addresses some problems related to the control of multiple robots. The techniques used to date in the modeling of closed kinematic chains are summarized. Various efforts made to date for the control of coordinated multiple manipulators is summarized.

  1. An effective hierarchical model for the biomolecular covalent bond: an approach integrating artificial chemistry and an actual terrestrial life system.

    PubMed

    Oohashi, Tsutomu; Ueno, Osamu; Maekawa, Tadao; Kawai, Norie; Nishina, Emi; Honda, Manabu

    2009-01-01

    Under the AChem paradigm and the programmed self-decomposition (PSD) model, we propose a hierarchical model for the biomolecular covalent bond (HBCB model). This model assumes that terrestrial organisms arrange their biomolecules in a hierarchical structure according to the energy strength of their covalent bonds. It also assumes that they have evolutionarily selected the PSD mechanism of turning biological polymers (BPs) into biological monomers (BMs) as an efficient biomolecular recycling strategy We have examined the validity and effectiveness of the HBCB model by coordinating two complementary approaches: biological experiments using existent terrestrial life, and simulation experiments using an AChem system. Biological experiments have shown that terrestrial life possesses a PSD mechanism as an endergonic, genetically regulated process and that hydrolysis, which decomposes a BP into BMs, is one of the main processes of such a mechanism. In simulation experiments, we compared different virtual self-decomposition processes. The virtual species in which the self-decomposition process mainly involved covalent bond cleavage from a BP to BMs showed evolutionary superiority over other species in which the self-decomposition process involved cleavage from BP to classes lower than BM. These converging findings strongly support the existence of PSD and the validity and effectiveness of the HBCB model.

  2. Intelligent multiagent coordination based on reinforcement hierarchical neuro-fuzzy models.

    PubMed

    Mendoza, Leonardo Forero; Vellasco, Marley; Figueiredo, Karla

    2014-12-01

    This paper presents the research and development of two hybrid neuro-fuzzy models for the hierarchical coordination of multiple intelligent agents. The main objective of the models is to have multiple agents interact intelligently with each other in complex systems. We developed two new models of coordination for intelligent multiagent systems, which integrates the Reinforcement Learning Hierarchical Neuro-Fuzzy model with two proposed coordination mechanisms: the MultiAgent Reinforcement Learning Hierarchical Neuro-Fuzzy with a market-driven coordination mechanism (MA-RL-HNFP-MD) and the MultiAgent Reinforcement Learning Hierarchical Neuro-Fuzzy with graph coordination (MA-RL-HNFP-CG). In order to evaluate the proposed models and verify the contribution of the proposed coordination mechanisms, two multiagent benchmark applications were developed: the pursuit game and the robot soccer simulation. The results obtained demonstrated that the proposed coordination mechanisms greatly improve the performance of the multiagent system when compared with other strategies.

  3. Multiple model predictive control for a hybrid proton exchange membrane fuel cell system

    NASA Astrophysics Data System (ADS)

    Chen, Qihong; Gao, Lijun; Dougal, Roger A.; Quan, Shuhai

    This paper presents a hierarchical predictive control strategy to optimize both power utilization and oxygen control simultaneously for a hybrid proton exchange membrane fuel cell/ultracapacitor system. The control employs fuzzy clustering-based modeling, constrained model predictive control, and adaptive switching among multiple models. The strategy has three major advantages. First, by employing multiple piecewise linear models of the nonlinear system, we are able to use linear models in the model predictive control, which significantly simplifies implementation and can handle multiple constraints. Second, the control algorithm is able to perform global optimization for both the power allocation and oxygen control. As a result, we can achieve the optimization from the entire system viewpoint, and a good tradeoff between transient performance of the fuel cell and the ultracapacitor can be obtained. Third, models of the hybrid system are identified using real-world data from the hybrid fuel cell system, and models are updated online. Therefore, the modeling mismatch is minimized and high control accuracy is achieved. Study results demonstrate that the control strategy is able to appropriately split power between fuel cell and ultracapacitor, avoid oxygen starvation, and so enhance the transient performance and extend the operating life of the hybrid system.

  4. Hierarchical multiple bit clusters and patterned media enabled by novel nanofabrication techniques -- High resolution electron beam lithography and block polymer self assembly

    NASA Astrophysics Data System (ADS)

    Xiao, Qijun

    This thesis discusses the full scope of a project exploring the physics of hierarchical clusters of interacting nanomagnets. These clusters may be relevant for novel applications such as multilevel data storage devices. The work can be grouped into three main activities: micromagnetic simulation, fabrication and characterization of proof-of-concept prototype devices, and efforts to scale down the structures by creating the hierarchical structures with the aid of diblock copolymer self assembly. Theoretical micromagnetic studies and simulations based on Landau-Lifshitz-Gilbert (LLG) equation were conducted on nanoscale single domain magnetic entities. For the simulated nanomagnet clusters with perpendicular uniaxial anisotropy, the simulation showed the switching field distributions, the stability of the magnetostatic states with distinctive total cluster perpendicular moments, and the stepwise magnetic switching curves. For simulated nanomagnet clusters with in-plane shape anisotropy, the simulation showed the stepwise switching behaviors governed by thermal agitation and cluster configurations. Proof-of-concept cluster devices with three interacting Co nanomagnets were fabricated by e-beam lithography (EBL) and pulse-reverse electrochemical deposition (PRECD). EBL patterning on a suspended 100 nm SiN membrane showed improved lateral lithography resolution to 30 nm. The Co nanomagnets deposited using the PRECD method showed perpendicular anisotropy. The switching experiments with external applied fields were able to switch the Co nanomagnets through the four magnetostatic states with distinctive total perpendicular cluster magnetization, and proved the feasibility of multilevel data storage devices based on the cluster concept. Shrinking the structures size was experimented by the aid of diblock copolymer. Thick poly(styrene)-b-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer templates aligned with external electrical field were used to fabricate long Ni

  5. Towards translational therapies for multiple system atrophy

    PubMed Central

    Kuzdas-Wood, Daniela; Stefanova, Nadia; Jellinger, Kurt A.; Seppi, Klaus; Schlossmacher, Michael G.; Poewe, Werner; Wenning, Gregor K.

    2014-01-01

    Multiple system atrophy (MSA) is a fatal adult-onset neurodegenerative disorder of uncertain etiopathogenesis manifesting with autonomic failure, parkinsonism, and ataxia in any combination. The underlying neuropathology affects central autonomic, striatonigral and olivopontocerebellar pathways and it is associated with distinctive glial cytoplasmic inclusions (GCIs, Papp-Lantos bodies) that contain aggregates of α-synuclein. Current treatment options are very limited and mainly focused on symptomatic relief, whereas disease modifying options are lacking. Despite extensive testing, no neuroprotective drug treatment has been identified up to now; however, a neurorestorative approach utilizing autologous mesenchymal stem cells has shown remarkable beneficial effects in the cerebellar variant of MSA. Here, we review the progress made over the last decade in defining pathogenic targets in MSA and summarize insights gained from candidate disease-modifying interventions that have utilized a variety of well-established preclinical MSA models. We also discuss the current limitations that our field faces and suggest solutions for possible approaches in cause-directed therapies of MSA. PMID:24598411

  6. Novel Therapeutic Approaches in Multiple System Atrophy

    PubMed Central

    Palma, Jose-Alberto; Kaufmann, Horacio

    2014-01-01

    Multiple system atrophy (MSA) is a sporadic, adult onset, relentlessly, progressive neurodegenerative disease characterized by autonomic abnormalities associated with parkinsonism, cerebellar dysfunction, pyramidal signs, or combinations thereof. Treatments that can halt or reverse the progression of MSA have not yet been identified. MSA is neuropathologically defined by the presence of α-synuclein–containing inclusions, particularly in the cytoplasm of oligodendrocytes (glial cytoplasmic inclusions, GCIs), which are associated with neurodegeneration. The mechanisms by which oligodendrocytic α-synuclein inclusions cause neuronal death in MSA are not completely understood. The MSA neurodegenerative process likely comprise cell-to-cell transmission of α-synuclein in a prion-like manner, α-synuclein aggregation, increased oxidative stress, abnormal expression of tubulin proteins, decreased expression of neurotrophic factors, excitotoxicity and microglial activation, and neuroinflammation. In an attempt to block each of these pathogenic mechanisms, several pharmacologic approaches have been tried and shown to exert neuroprotective effects in transgenic mouse or cellular models of MSA. These include sertraline, paroxetine, and lithium, which hamper arrival of α-synuclein to oligodendroglia; rifampicin, lithium, and non-steroidal anti-inflamatory drugs, which inhibit α-synuclein aggregation in oligodendrocytes; riluzole, rasagiline, fluoxetine and mesenchimal stem cells, which exert neuroprotective actions; and minocycline and intravenous immunoglobulins, which reduce neuroinflammation and microglial activation. These and other potential therapeutic strategies for MSA are summarized in this review. PMID:24928797

  7. Inhibiting multiple mode vibration in controlled flexible systems

    NASA Technical Reports Server (NTRS)

    Hyde, James M.; Chang, Kenneth W.; Seering, Warren P.

    1991-01-01

    Viewgraphs on inhibiting multiple mode vibration in controlled flexible systems are presented. Topics covered include: input pre-shaping background; developing multiple-mode shapers; Middeck Active Control Experiment (MACE) test article; and tests and results.

  8. Dynamics of quantum dissipation systems interacting with fermion and boson grand canonical bath ensembles: hierarchical equations of motion approach.

    PubMed

    Jin, Jinshuang; Welack, Sven; Luo, JunYan; Li, Xin-Qi; Cui, Ping; Xu, Rui-Xue; Yan, YiJing

    2007-04-07

    A hierarchical equations of motion formalism for a quantum dissipation system in a grand canonical bath ensemble surrounding is constructed on the basis of the calculus-on-path-integral algorithm, together with the parametrization of arbitrary non-Markovian bath that satisfies fluctuation-dissipation theorem. The influence functionals for both the fermion or boson bath interaction are found to be of the same path integral expression as the canonical bath, assuming they all satisfy the Gaussian statistics. However, the equation of motion formalism is different due to the fluctuation-dissipation theories that are distinct and used explicitly. The implications of the present work to quantum transport through molecular wires and electron transfer in complex molecular systems are discussed.

  9. Guided Multiple Launch Rocket System/Guided Multiple Launch Rocket System Alternative Warhead (GMLRS/GMLRS AW)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-260 Guided Multiple Launch Rocket System/Guided Multiple Launch Rocket System Alternative...James Mills Presion Fires Rocket and Missile Systems Project Office 5250 Martin Road Redstone Arsenal, AL 35898-8000 james.c.mills18.mil@mail.mil...Launch Rocket System/Guided Multiple Launch Rocket System Alternative Warhead (GMLRS/GMLRS AW) DoD Component Army Responsible Office References SAR

  10. Parabrachial nucleus involvement in multiple system atrophy☆

    PubMed Central

    Benarroch, E.E.; Schmeichel, A.M.; Low, P.A.; Parisi, J.E.

    2014-01-01

    Multiple system atrophy (MSA) is associated with respiratory dysfunction, including sleep apnea, respiratory dysrhythmia, and laryngeal stridor. Neurons of the parabrachial nucleus (PBN) control respiratory rhythmogenesis and airway resistance. Objectives The objective of this study is to determine whether there was involvement of putative respiratory regions of the PBN in MSA. Methods We examined the pons at autopsy in 10 cases with neuropathologically confirmed MSA and 8 age-matched controls. Sections obtained throughout the pons were processed for calcitonin-gene related peptide (CGRP) and Nissl staining to identify the lateral crescent of the lateral PBN (LPB) and the Kölliker-Fuse nucleus (K-F), which are involved in respiratory control. Cell counts were performed using stereology. Results There was loss of CGRP neurons in the PBN in MSA (total estimated cell counts for the external LPB cluster was 12,584 ± 1146 in controls and 5917 ± 389 in MSA, p < 0.0001); for the external medial PBN (MPB) cluster it was 15,081 ± 1758 in controls and 7842 ± 466 in MSA, p < 0.001. There was also neuronal loss in putative respiratory regions of the PBN, including the lateral crescent of the LPB (13,039 ± 1326 in controls and 4164 ± 872 in MSA, p < 0.0001); and K-F (5120 ± 495 in controls and 999 ± 308 in MSA, p < 0.0001). Conclusions There is involvement of both CGRP and putative respiratory cell groups in the PBN in MSA. Whereas the clinical implications of CGRP cell loss are still undetermined, involvement of the LPB and K-F may contribute to respiratory dysfunction in this disorder. PMID:23665165

  11. MAPT haplotype diversity in multiple system atrophy

    PubMed Central

    Labbé, Catherine; Heckman, Michael G.; Lorenzo-Betancor, Oswaldo; Murray, Melissa E.; Ogaki, Kotaro; Soto-Ortolaza, Alexandra I.; Walton, Ronald L.; Fujioka, Shinsuke; Koga, Shunsuke; Uitti, Ryan J.; van Gerpen, Jay A.; Petersen, Ronald C.; Graff-Radford, Neill R.; Younkin, Steven G.; Boeve, Bradley F.; Cheshire, William P.; Low, Phillip A.; Sandroni, Paola; Coon, Elizabeth A.; Singer, Wolfgang; Wszolek, Zbigniew K.; Dickson, Dennis W.; Ross, Owen A.

    2016-01-01

    Introduction Multiple system atrophy (MSA) is a rare progressive neurodegenerative disorder. MSA was originally considered exclusively sporadic but reports of association with genes such as SNCA, COQ2 and LRRK2 have demonstrated that there is a genetic contribution to the disease. MAPT has been associated with several neurodegenerative diseases and we previously reported a protective association of the MAPT H2 haplotype with MSA in 61 pathologically confirmed cases. Methods In the present study, we assessed the full MAPT haplotype diversity in MSA patients using six MAPT tagging SNPs. We genotyped a total of 127 pathologically confirmed MSA cases, 86 patients with clinically diagnosed MSA and 1312 controls. Results We identified four significant association signals in our pathologically confirmed cases, two from the protective haplotypes H2 (MSA:16.2%, Controls:22.7%, p=0.024) and H1E (MSA:3.0%, Controls:9.0%, p=0.014), and two from the rare risk haplotypes H1x (MSA:3.7%, Controls:1.3%, p=0.030) and H1J (MSA:3.0%, Controls:0.9%, p=0.021). We evaluated the association of MSA subtypes with the common protective H2 haplotype and found a significant difference with controls for MSA patients with some degree of MSA-C (MSA-C or MSA-mixed), for whom H2 occurred in only 8.6% of patients in our pathologically confirmed series (P<0.0001). Conclusions Our findings provide further evidence that MAPT variation is associated with risk of MSA. Interestingly, our results suggest a greater effect size in the MSA-C compared to MSA-P for H2. Additional genetic studies in larger pathologically confirmed MSA series and meta-analytic studies will be needed to fully assess the role of MAPT and other genes in MSA. PMID:27374978

  12. Defining and Enabling Resiliency of Electric Distribution Systems With Multiple Microgrids

    SciTech Connect

    Chanda, Sayonsom; Srivastava, Anurag K.

    2016-05-02

    This paper presents a method for quantifying and enabling the resiliency of a power distribution system (PDS) using analytical hierarchical process and percolation theory. Using this metric, quantitative analysis can be done to analyze the impact of possible control decisions to pro-actively enable the resilient operation of distribution system with multiple microgrids and other resources. Developed resiliency metric can also be used in short term distribution system planning. The benefits of being able to quantify resiliency can help distribution system planning engineers and operators to justify control actions, compare different reconfiguration algorithms, develop proactive control actions to avert power system outage due to impending catastrophic weather situations or other adverse events. Validation of the proposed method is done using modified CERTS microgrids and a modified industrial distribution system. Furthermore, simulation results show topological and composite metric considering power system characteristics to quantify the resiliency of a distribution system with the proposed methodology, and improvements in resiliency using two-stage reconfiguration algorithm and multiple microgrids.

  13. Defining and enabling resiliency of electric distribution systems with multiple microgrids

    SciTech Connect

    Chanda, Sayonsom; Srivastava, Anurag K.

    2016-05-02

    This paper presents a method for quantifying and enabling the resiliency of a power distribution system (PDS) using analytical hierarchical process and percolation theory. Using this metric, quantitative analysis can be done to analyze the impact of possible control decisions to pro-actively enable the resilient operation of distribution system with multiple microgrids and other resources. Developed resiliency metric can also be used in short term distribution system planning. The benefits of being able to quantify resiliency can help distribution system planning engineers and operators to justify control actions, compare different reconfiguration algorithms, develop proactive control actions to avert power system outage due to impending catastrophic weather situations or other adverse events. Validation of the proposed method is done using modified CERTS microgrids and a modified industrial distribution system. Furthermore, simulation results show topological and composite metric considering power system characteristics to quantify the resiliency of a distribution system with the proposed methodology, and improvements in resiliency using two-stage reconfiguration algorithm and multiple microgrids.

  14. Hierarchical structure in a self-created communication system: Building nominal constituents in homesign

    PubMed Central

    Hunsicker, Dea; Goldin-Meadow, Susan

    2013-01-01

    Deaf children whose hearing losses are so severe that they cannot acquire spoken language and whose hearing parents have not exposed them to sign language nevertheless use gestures, called homesigns, to communicate. Homesigners have been shown to refer to entities by pointing at that entity (a demonstrative, that). They also use iconic gestures and category points that refer, not to a particular entity, but to its class (a noun, bird). We used longitudinal data from a homesigner called David to test the hypothesis that these different types of gestures are combined to form larger, multi-gesture nominal constituents (that bird). We verified this hypothesis by showing that David's multi-gesture combinations served the same semantic and syntactic functions as demonstrative gestures or noun gestures used on their own. In other words, the larger unit substituted for the smaller units and, in this way, functioned as a nominal constituent. Children are thus able to refer to entities using multi-gesture units that contain both nouns and demonstratives, even when they do not have a conventional language to provide a model for this type of hierarchical constituent structure.* PMID:23626381

  15. Distributed mixed-integer fuzzy hierarchical programming for municipal solid waste management. Part I: System identification and methodology development.

    PubMed

    Cheng, Guanhui; Huang, Guohe; Dong, Cong; Xu, Ye; Chen, Xiujuan; Chen, Jiapei

    2017-03-01

    Due to the existence of complexities of heterogeneities, hierarchy, discreteness, and interactions in municipal solid waste management (MSWM) systems such as Beijing, China, a series of socio-economic and eco-environmental problems may emerge or worsen and result in irredeemable damages in the following decades. Meanwhile, existing studies, especially ones focusing on MSWM in Beijing, could hardly reflect these complexities in system simulations and provide reliable decision support for management practices. Thus, a framework of distributed mixed-integer fuzzy hierarchical programming (DMIFHP) is developed in this study for MSWM under these complexities. Beijing is selected as a representative case. The Beijing MSWM system is comprehensively analyzed in many aspects such as socio-economic conditions, natural conditions, spatial heterogeneities, treatment facilities, and system complexities, building a solid foundation for system simulation and optimization. Correspondingly, the MSWM system in Beijing is discretized as 235 grids to reflect spatial heterogeneity. A DMIFHP model which is a nonlinear programming problem is constructed to parameterize the Beijing MSWM system. To enable scientific solving of it, a solution algorithm is proposed based on coupling of fuzzy programming and mixed-integer linear programming. Innovations and advantages of the DMIFHP framework are discussed. The optimal MSWM schemes and mechanism revelations will be discussed in another companion paper due to length limitation.

  16. booc.io: An Education System with Hierarchical Concept Maps and Dynamic Non-linear Learning Plans.

    PubMed

    Schwab, Michail; Strobelt, Hendrik; Tompkin, James; Fredericks, Colin; Huff, Connor; Higgins, Dana; Strezhnev, Anton; Komisarchik, Mayya; King, Gary; Pfister, Hanspeter

    2017-01-01

    Information hierarchies are difficult to express when real-world space or time constraints force traversing the hierarchy in linear presentations, such as in educational books and classroom courses. We present booc.io, which allows linear and non-linear presentation and navigation of educational concepts and material. To support a breadth of material for each concept, booc.io is Web based, which allows adding material such as lecture slides, book chapters, videos, and LTIs. A visual interface assists the creation of the needed hierarchical structures. The goals of our system were formed in expert interviews, and we explain how our design meets these goals. We adapt a real-world course into booc.io, and perform introductory qualitative evaluation with students.

  17. Anti-disturbance control theory for systems with multiple disturbances: a survey.

    PubMed

    Guo, Lei; Cao, Songyin

    2014-07-01

    The problem of anti-disturbance control has been an eternal topic along with the development of the control theory. However, most methodologies can only deal with systems subject to a single equivalent disturbance which was merged by various types of uncertainties. In this paper, a review on anti-disturbance control is presented for systems with multiple disturbances. First, the classical control methods are briefly reviewed for disturbance attenuation or rejection problems. Then, recent advances in disturbance observer based control (DOBC) theory are introduced and especially, the composite hierarchical anti-disturbance control (CHADC) is firstly addressed. A comparison of different approaches is briefly carried out. Finally, focuses in the field on the current research are also addressed with emphasis on the practical application of the techniques.

  18. Hierarchical multisensor analysis for robotic exploration

    NASA Astrophysics Data System (ADS)

    Eberlein, Susan; Yates, Gigi; Majani, Eric

    1991-03-01

    Robotic vehicles for lunar and Mars exploration will carry an array of complex instruments requiring real-time data interpretation and fusion. The system described here uses hierarchical multiresolution analysis of visible and multispectral images to extract information on mineral composition, texture and object shape. This information is used to characterize the site geology and choose interesting samples for acquisition. Neural networks are employed for many data analysis steps. A decision tree progressively integrates information from multiple instruments and performs goal-driven decision making. The system is designed to incorporate more instruments and data types as they become available.

  19. Hierarchical multisensor analysis for robotic exploration

    NASA Technical Reports Server (NTRS)

    Eberlein, Susan; Yates, Gigi; Majani, Eric

    1991-01-01

    Robotic vehicles for lunar and Mars exploration will carry an array of complex instruments requiring real-time data interpretation and fusion. The system described here uses hierarchical multiresolution analysis of visible and multispectral images to extract information on mineral composition, texture and object shape. This information is used to characterize the site geology and choose interesting samples for acquisition. Neural networks are employed for many data analysis steps. A decision tree progressively integrates information from multiple instruments and performs goal-driven decision making. The system is designed to incorporate more instruments and data types as they become available.

  20. A hierarchical 3D segmentation method and the definition of vertebral body coordinate systems for QCT of the lumbar spine.

    PubMed

    Mastmeyer, André; Engelke, Klaus; Fuchs, Christina; Kalender, Willi A

    2006-08-01

    We have developed a new hierarchical 3D technique to segment the vertebral bodies in order to measure bone mineral density (BMD) with high trueness and precision in volumetric CT datasets. The hierarchical approach starts with a coarse separation of the individual vertebrae, applies a variety of techniques to segment the vertebral bodies with increasing detail and ends with the definition of an anatomic coordinate system for each vertebral body, relative to which up to 41 trabecular and cortical volumes of interest are positioned. In a pre-segmentation step constraints consisting of Boolean combinations of simple geometric shapes are determined that enclose each individual vertebral body. Bound by these constraints viscous deformable models are used to segment the main shape of the vertebral bodies. Volume growing and morphological operations then capture the fine details of the bone-soft tissue interface. In the volumes of interest bone mineral density and content are determined. In addition, in the segmented vertebral bodies geometric parameters such as volume or the length of the main axes of inertia can be measured. Intra- and inter-operator precision errors of the segmentation procedure were analyzed using existing clinical patient datasets. Results for segmented volume, BMD, and coordinate system position were below 2.0%, 0.6%, and 0.7%, respectively. Trueness was analyzed using phantom scans. The bias of the segmented volume was below 4%; for BMD it was below 1.5%. The long-term goal of this work is improved fracture prediction and patient monitoring in the field of osteoporosis. A true 3D segmentation also enables an accurate measurement of geometrical parameters that may augment the clinical value of a pure BMD analysis.

  1. A search for tight hierarchical triple systems amongst the eclipsing binaries in the CoRoT fields

    NASA Astrophysics Data System (ADS)

    Hajdu, T.; Borkovits, T.; Forgács-Dajka, E.; Sztakovics, J.; Marschalkó, G.; Benkő, J. M.; Klagyivik, P.; Sallai, M. J.

    2017-10-01

    We report a comprehensive search for hierarchical triple stellar system candidates amongst eclipsing binaries (EBs) observed by the CoRoT spacecraft. We calculate and check eclipse timing variation (ETV) diagrams for almost 1500 EBs in an automated manner. We identify five relatively short period Algol systems for which our combined light-curve and complex ETV analyses (including both the light-travel time effect and short-term dynamical third-body perturbations) resulted in consistent third-body solutions. The computed periods of the outer bodies are between 82 and 272 d (with an alternative solution of 831 d for one of the targets). We find that the inner and outer orbits are near coplanar in all but one case. The dynamical masses of the outer subsystems determined from the ETV analyses are consistent with both the results of our light-curve analyses and the spectroscopic information available in the literature. One of our candidate systems exhibits outer eclipsing events as well, the locations of which are in good agreement with the ETV solution. We also report another certain triply eclipsing triple system that, however, is lacking a reliable ETV solution due to the very short time range of the data, and four new blended systems (composite light curves of two EBs each), where we cannot decide whether the components are gravitationally bounded or not. Amongst these blended systems, we identify the longest period and highest eccentricity EB in the entire CoRoT sample.

  2. Multiple-channel Streaming Delivery for Omnidirectional Vision System

    NASA Astrophysics Data System (ADS)

    Iwai, Yoshio; Nagahara, Hajime; Yachida, Masahiko

    An omnidirectional vision is an imaging system that can capture a surrounding image in whole direction by using a hyperbolic mirror and a conventional CCD camera. This paper proposes a streaming server that can efficiently transfer movies captured by an omnidirectional vision system through the Internet. The proposed system uses multiple channels to deliver multiple movies synchronously. Through this method, the system enables clients to view the different direction of omnidirectional movies and also support the function to change the view are during playback period. Our evaluation experiments show that our proposed streaming server can effectively deliver multiple movies via multiple channels.

  3. Quantifying rock's structural fabric: a multi-scale hierarchical approach to natural fracture systems and stochastic modelling

    NASA Astrophysics Data System (ADS)

    Hardebol, Nico; Bertotti, Giovanni; Weltje, Gert Jan

    2014-05-01

    We propose the description of fracture-fault systems in terms of a multi-scale hierarchical network. In most generic form, such arrangement is referred to as a structural fabric and applicable across the length scale spectrum. The statistical characterisation combines the fracture length and orientation distributions and intersection-termination relationships. The aim is a parameterised description of the network that serves as input in stochastic network simulations that should reproduce the essence of natural fracture networks and encompass its variability. The quality of the stochastically generated fabric is determined by comparison with deterministic descriptions on which the model parameterisation is based. Both the deterministic and stochastic derived fracture network description can serve as input in fluid flow or mechanical simulations that accounts explicitly for the discrete features and the response of the system can be compared. The deterministic description of our current study in the framework of tight gas reservoirs is obtained from coastal pavements that expose a horizontal slice through a fracture-fault network system in fine grained sediments in Yorkshire, UK. Fracture hierarchies have often been described at one observation scale as a two-tier hierarchy in terms of 1st order systematic joints and 2nd order cross-joints. New in our description is the bridging between km-sized faults with notable displacement down to sub-meter scale shear and opening mode fractures. This study utilized a drone to obtain cm-resolution imagery of pavements from ~30m altitude and the large coverage up to 1-km by flying at a ~80m. This unique set of images forms the basis for the digitizing of the fracture-fault pattern and helped determining the nested nature of the network as well as intersection and abutment relationships. Fracture sets were defined from the highest to lowest hierarchical order and probability density functions were defined for the length

  4. Control of multiple resonant power processors in a multi-source system

    NASA Technical Reports Server (NTRS)

    Mildice, James; Silverman, Albert; Kenny, Barbara

    1990-01-01

    Analysis and test results show that phasor-regulated, Mapham-derived resonant inverters can be paralleled to provide standardizing interfaces for multiple sources on a utility-type, aerospace power distribution bus. The basic sources do not require matching in any way, and may have grossly different characteristics. Fully stable system architectures with multiple sources, parallel/redundant distribution buses, and a wide variety of loads can be easily constructed and controlled. The commands and parameters available for system control allow for tight tolerance bus voltage control, and absolute power-sharing control from the various sources over the full range of possible source and load variations. That level of control enables simplified load power processing hardware and the distribution of losses to optimally load the source thermal control system. Positive control of all system performance and allocation of losses are not required by all missions or vehicles, and overall vehicle considerations do not always require the loads on vehicle energy sources and thermal control systems to be balanced. In those cases, power system control can be simplified, and a hierarchical set of defaults can be substituted for computer-generated or supervisory input commands to allow for stable, fully autonomous system operation.

  5. Defining and Enabling Resiliency of Electric Distribution Systems With Multiple Microgrids

    DOE PAGES

    Chanda, Sayonsom; Srivastava, Anurag K.

    2016-05-02

    This paper presents a method for quantifying and enabling the resiliency of a power distribution system (PDS) using analytical hierarchical process and percolation theory. Using this metric, quantitative analysis can be done to analyze the impact of possible control decisions to pro-actively enable the resilient operation of distribution system with multiple microgrids and other resources. Developed resiliency metric can also be used in short term distribution system planning. The benefits of being able to quantify resiliency can help distribution system planning engineers and operators to justify control actions, compare different reconfiguration algorithms, develop proactive control actions to avert power systemmore » outage due to impending catastrophic weather situations or other adverse events. Validation of the proposed method is done using modified CERTS microgrids and a modified industrial distribution system. Furthermore, simulation results show topological and composite metric considering power system characteristics to quantify the resiliency of a distribution system with the proposed methodology, and improvements in resiliency using two-stage reconfiguration algorithm and multiple microgrids.« less

  6. Control of multiple resonant power processors in a multi-source system

    NASA Technical Reports Server (NTRS)

    Mildice, James; Silverman, Albert; Kenny, Barbara

    1990-01-01

    Analysis and test results show that phasor-regulated, Mapham-derived resonant inverters can be paralleled to provide standardizing interfaces for multiple sources on a utility-type, aerospace power distribution bus. The basic sources do not require matching in any way, and may have grossly different characteristics. Fully stable system architectures with multiple sources, parallel/redundant distribution buses, and a wide variety of loads can be easily constructed and controlled. The commands and parameters available for system control allow for tight tolerance bus voltage control, and absolute power-sharing control from the various sources over the full range of possible source and load variations. That level of control enables simplified load power processing hardware and the distribution of losses to optimally load the source thermal control system. Positive control of all system performance and allocation of losses are not required by all missions or vehicles, and overall vehicle considerations do not always require the loads on vehicle energy sources and thermal control systems to be balanced. In those cases, power system control can be simplified, and a hierarchical set of defaults can be substituted for computer-generated or supervisory input commands to allow for stable, fully autonomous system operation.

  7. Defining and enabling resiliency of electric distribution systems with multiple microgrids

    DOE PAGES

    Chanda, Sayonsom; Srivastava, Anurag K.

    2016-05-02

    This paper presents a method for quantifying and enabling the resiliency of a power distribution system (PDS) using analytical hierarchical process and percolation theory. Using this metric, quantitative analysis can be done to analyze the impact of possible control decisions to pro-actively enable the resilient operation of distribution system with multiple microgrids and other resources. Developed resiliency metric can also be used in short term distribution system planning. The benefits of being able to quantify resiliency can help distribution system planning engineers and operators to justify control actions, compare different reconfiguration algorithms, develop proactive control actions to avert power systemmore » outage due to impending catastrophic weather situations or other adverse events. Validation of the proposed method is done using modified CERTS microgrids and a modified industrial distribution system. Furthermore, simulation results show topological and composite metric considering power system characteristics to quantify the resiliency of a distribution system with the proposed methodology, and improvements in resiliency using two-stage reconfiguration algorithm and multiple microgrids.« less

  8. Multiple operating system rotation environment moving target defense

    DOEpatents

    Evans, Nathaniel; Thompson, Michael

    2016-03-22

    Systems and methods for providing a multiple operating system rotation environment ("MORE") moving target defense ("MTD") computing system are described. The MORE-MTD system provides enhanced computer system security through a rotation of multiple operating systems. The MORE-MTD system increases attacker uncertainty, increases the cost of attacking the system, reduces the likelihood of an attacker locating a vulnerability, and reduces the exposure time of any located vulnerability. The MORE-MTD environment is effectuated by rotation of the operating systems at a given interval. The rotating operating systems create a consistently changing attack surface for remote attackers.

  9. Reliability optimization design of distribution systems via multi-level hierarchical procedures and generalized reduced gradient method

    SciTech Connect

    Su, C.T.; Lii, G.R.

    1995-12-31

    The purpose of this paper is to develop an optimization method for reliable design of substations. Reliability indices used are failure rate and interruption duration, which are commonly used in the distribution systems. Through applying the proposed method, the optimal reliability indices of apparatus are obtained, which minimize the total cost comprising apparatus investment cost and interruption cost, and also satisfy reliability constraints of load point. Three kinds of interruption cost including initial interruption cost, outage frequency cost and interruption duration cost are considered. The optimization technique employed in this paper to solve the nonlinear programming problems is the Generalized Reduced Gradient (GRG) method. For simplification of computation of large or complex systems, the multi-level hierarchical optimization is applied. It starts by dividing the system into several subsystems, and finds the optimal reliability indices for subsystems. Then by repeatedly taking the previous subsystem as the following system and the previous constituent as the following subsystem, and applying the GRG method, the authors can finally find the desired reliability indices for components of the primitive system. To demonstrate the application of the method, a secondary substation of the Taiwan Power Company is taken as an example, computation results of the application example show that the interruption cost is effectively reduced. The proposed method is applicable to existing substation expansion and new substation establishment.

  10. Hierarchical patch dynamics and animal movement pattern.

    PubMed

    Fauchald, Per; Tveraa, Torkild

    2006-09-01

    In hierarchical patch systems, small-scale patches of high density are nested within large-scale patches of low density. The organization of multiple-scale hierarchical systems makes non-random strategies for dispersal and movement particularly important. Here, we apply a new method based on first-passage time on the pathway of a foraging seabird, the Antarctic petrel (Thalassoica antarctica), to quantify its foraging pattern and the spatial dynamics of its foraging areas. Our results suggest that Antarctic petrels used a nested search strategy to track a highly dynamic hierarchical patch system where small-scale patches were congregated within patches at larger scales. The birds searched for large-scale patches by traveling fast and over long distances. Once within a large-scale patch, the birds concentrated their search to find smaller scale patches. By comparing the pathway of different birds we were able to quantify the spatial scale and turnover of their foraging areas. On the largest scale we found foraging areas with a characteristic scale of about 400 km. Nested within these areas we found foraging areas with a characteristic scale of about 100 km. The large-scale areas disappeared or moved within a time frame of weeks while the nested small-scale areas disappeared or moved within days. Antarctic krill (Euphausia superba) is the dominant food item of Antarctic petrels and we suggest that our findings reflect the spatial dynamics of krill in the area.

  11. Multiple Thesauri in Online Library Bibliographic Systems.

    ERIC Educational Resources Information Center

    Mandel, Carol A.

    This report responds to the need for North American libraries to provide computer support for multiple subject lists or controlled vocabularies as they automate separate catalogs using specialized thesauri for certain subject areas, materials, and audiences in addition to their main library catalogs. The focus of the report is the integration of…

  12. Multiple myeloma international staging system: "staging" or simply "aging" system?

    PubMed

    Bataille, Regis; Annweiler, Cedric; Beauchet, Olivier

    2013-12-01

    Because of the wide variation in multiple myeloma (MM) survival, numerous studies have focused over the past 40 years on the biological and cytogenetic prognostic values in MM patients. Since 2005, the MM International Staging System (ISS) has recognized the combination of beta-2 microglobulin (β2M) with serum albumin (SA) concentrations as the most simple and potent combination to determine the prognosis in MM patients. Curiously, the reasons for the efficiency of the combination of β2M with SA remain not clear-cut. In 2007, Fonseca and San Miguel (Prognostic factors and staging in multiple myeloma. Hematol Oncol Clin North Am 2007; 21:1115-40) underlined that cytogenetic assessment might also be useful for evaluating MM prognosis. Furthermore, new perspectives recently appeared with the genomic approach. Here, we (1) question the specific rationale for β2M and SA as prognostic markers in MM, (2) emphasize the well-documented prognostic implications of β2M and SA as potent biomarkers of comorbidity in older adults, and (3) conclude that the current MM-ISS is rather a staging system for age-related comorbidity burden (ie, aging system) than a specific MM staging system, and should not be used alone. Thus, we suggest that: (1) cytogenetics with the superscript MM-ISS could be the standard method; (2) some factors discovered using genomics could reflect the comorbidity burden and the intrinsic malignancy of MM clone, and thus needs more investigation; and (3) while waiting for standard genomic classification. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. A RESOLVED CENSUS OF MILLIMETER EMISSION FROM TAURUS MULTIPLE STAR SYSTEMS

    SciTech Connect

    Harris, Robert J.; Andrews, Sean M.; Wilner, David J.; Kraus, Adam L.

    2012-06-01

    We present a high angular resolution millimeter-wave dust continuum imaging survey of circumstellar material associated with the individual components of 23 multiple star systems in the Taurus-Auriga young cluster. Combined with previous measurements in the literature, these new data permit a comprehensive look at how the millimeter luminosity (a rough tracer of disk mass) relates to the separation and mass of a stellar companion. Approximately one-third (28%-37%) of the individual stars in multiple systems have detectable millimeter emission, an incidence rate half that for single stars ({approx}62%) which does not depend on the number of companions. There is a strong, positive correlation between the luminosity and projected separation (a{sub p} ) of a stellar pair. Wide pairs (a{sub p} > 300 AU) have a similar luminosity distribution as single stars, medium pairs (a{sub p} Almost-Equal-To 30-300 AU) are a factor of five fainter, and close pairs (a{sub p} < 30 AU) are {approx}5 Multiplication-Sign fainter yet (aside from a small, but notable population of bright circumbinary disks). In most cases, the emission is dominated by a disk around the primary (or a wide tertiary in hierarchical triples), but there is no clear relationship between luminosity and stellar mass ratio. A direct comparison of resolved disk sizes with predictions from tidal truncation models yields mixed results; some disks are much larger than expected given the projected distances of their companions. We suggest that the presence of a stellar companion impacts disk properties at a level comparable to the internal evolution mechanisms that operate in an isolated system, with both the multiple star formation process itself and star-disk tidal interactions likely playing important roles in the evolution of circumstellar material. From the perspective of the mass content of the disk reservoir, we expect that (giant) planet formation is inhibited around the components of close pairs or secondaries

  14. Exploring Neural Network Models with Hierarchical Memories and Their Use in Modeling Biological Systems

    NASA Astrophysics Data System (ADS)

    Pusuluri, Sai Teja

    Energy landscapes are often used as metaphors for phenomena in biology, social sciences and finance. Different methods have been implemented in the past for the construction of energy landscapes. Neural network models based on spin glass physics provide an excellent mathematical framework for the construction of energy landscapes. This framework uses a minimal number of parameters and constructs the landscape using data from the actual phenomena. In the past neural network models were used to mimic the storage and retrieval process of memories (patterns) in the brain. With advances in the field now, these models are being used in machine learning, deep learning and modeling of complex phenomena. Most of the past literature focuses on increasing the storage capacity and stability of stored patterns in the network but does not study these models from a modeling perspective or an energy landscape perspective. This dissertation focuses on neural network models both from a modeling perspective and from an energy landscape perspective. I firstly show how the cellular interconversion phenomenon can be modeled as a transition between attractor states on an epigenetic landscape constructed using neural network models. The model allows the identification of a reaction coordinate of cellular interconversion by analyzing experimental and simulation time course data. Monte Carlo simulations of the model show that the initial phase of cellular interconversion is a Poisson process and the later phase of cellular interconversion is a deterministic process. Secondly, I explore the static features of landscapes generated using neural network models, such as sizes of basins of attraction and densities of metastable states. The simulation results show that the static landscape features are strongly dependent on the correlation strength and correlation structure between patterns. Using different hierarchical structures of the correlation between patterns affects the landscape features

  15. A User Interface for Multiple Retrieval Systems.

    ERIC Educational Resources Information Center

    Teskey, Niall; And Others

    1987-01-01

    Reviews current systems designed to help end-users search online databases without the assistance of an intermediary and describes a prototype system which emulates the Deco (the text storage and retrieval system used by Unilever) interface on Dialog and Data-Star. Initial trials of the prototype system are reported. (15 references) (MES)

  16. Redundant Multiple-Valued Number Systems

    DTIC Science & Technology

    1997-07-01

    Fibonacci ou de nombres de Lucas ,” Bull. Soc. Royale Sci. Liege 41, 1972, pp. 179-182. 14-1 ABSTRACT We survey number systems in which the...Figure 5. The 4-Bit One’s Complement Number System. E. FIBONACCI NUMBER SYSTEM The Fibonacci number system is the second example of a redundant number ...instead of powers of 2 or -2, Fibonacci numbers are used as the base. In such a number system, there are many redundant representatives. Fig.

  17. Development of Stability/Robustness Considerations for Control System Design with Multiple Input/Multiple Output Plants

    DTIC Science & Technology

    1988-06-10

    multiple input / multiple output ( MIMO ...Unstable.80 Ut NOTATION MIMO Multiple Input / Multiple Output SISO Single Input /Single Output A,B,C Nominal Plant Matrices Acl Nominal Plant Closed...giving way to plants with multiple inputs and multiple outputs ( MIMO ) as technology races ahead. Extremely advanced systems such as the Navy’s

  18. Multiple channel secure communication using chaotic system encoding

    SciTech Connect

    Miller, S.L.

    1996-12-31

    fA new method to encrypt signals using chaotic systems has been developed that offers benefits over conventional chaotic encryption methods. The method simultaneously encodes multiple plaintext streams using a chaotic system; a key is required to extract the plaintext from the chaotic cipertext. A working prototype demonstrates feasibility of the method by simultaneously encoding and decoding multiple audio signals using electrical circuits.

  19. Validity and Realibility of Chemistry Systemic Multiple Choices Questions (CSMCQs)

    ERIC Educational Resources Information Center

    Priyambodo, Erfan; Marfuatun

    2016-01-01

    Nowadays, Rasch model analysis is used widely in social research, moreover in educational research. In this research, Rasch model is used to determine the validation and the reliability of systemic multiple choices question in chemistry teaching and learning. There were 30 multiple choices question with systemic approach for high school student…

  20. On Decision-Making Among Multiple Rule-Bases in Fuzzy Control Systems

    NASA Technical Reports Server (NTRS)

    Tunstel, Edward; Jamshidi, Mo

    1997-01-01

    Intelligent control of complex multi-variable systems can be a challenge for single fuzzy rule-based controllers. This class of problems cam often be managed with less difficulty by distributing intelligent decision-making amongst a collection of rule-bases. Such an approach requires that a mechanism be chosen to ensure goal-oriented interaction between the multiple rule-bases. In this paper, a hierarchical rule-based approach is described. Decision-making mechanisms based on generalized concepts from single-rule-based fuzzy control are described. Finally, the effects of different aggregation operators on multi-rule-base decision-making are examined in a navigation control problem for mobile robots.

  1. Structural system reliability under multiple failure modes

    NASA Technical Reports Server (NTRS)

    Mahadevan, S.; Chamis, C. C.

    1993-01-01

    This paper describes a computational method for system reliability estimation of propulsion structures. The failure domain of the entire structural system is computed through the union of failure regions for various critical system failure modes. The effect of non-critical progressive damage is incorporated through structural reanalysis, resulting in the construction of several linear segments to approximately cover the system failure domain. An adaptive damage imposition scheme is outlined for the sake of computational efficiency. The proposed method is used to construct the system survival cdf (cumulative distribution function) of a two-rotor system.

  2. Electroencephalography-based real-time cortical monitoring system that uses hierarchical Bayesian estimations for the brain-machine interface.

    PubMed

    Choi, Kyuwan

    2014-06-01

    In this study, a real-time cortical activity monitoring system was constructed, which could estimate cortical activities every 125 milliseconds over 2,240 vertexes from 64 channel electroencephalography signals through the Hierarchical Bayesian estimation that uses functional magnetic resonance imaging data as its prior information. Recently, functional magnetic resonance imaging has mostly been used in the neurofeedback field because it allows for high spatial resolution. However, in functional magnetic resonance imaging, the time for the neurofeedback information to reach the patient is delayed several seconds because of its poor temporal resolution. Therefore, a number of problems need to be solved to effectively implement feedback training paradigms in patients. To address this issue, this study used a new cortical activity monitoring system that improved both spatial and temporal resolution by using both functional magnetic resonance imaging data and electroencephalography signals in conjunction with one another. This system is advantageous as it can improve applications in the fields of real-time diagnosis, neurofeedback, and the brain-machine interface.

  3. Inter-subject Functional Correlation Reveal a Hierarchical Organization of Extrinsic and Intrinsic Systems in the Brain.

    PubMed

    Ren, Yudan; Nguyen, Vinh Thai; Guo, Lei; Guo, Christine Cong

    2017-09-07

    The brain is constantly monitoring and integrating both cues from the external world and signals generated intrinsically. These extrinsically and intrinsically-driven neural processes are thought to engage anatomically distinct regions, which are thought to constitute the extrinsic and intrinsic systems of the brain. While the specialization of extrinsic and intrinsic system is evident in primary and secondary sensory cortices, a systematic mapping of the whole brain remains elusive. Here, we characterized the extrinsic and intrinsic functional activities in the brain during naturalistic movie-viewing. Using a novel inter-subject functional correlation (ISFC) analysis, we found that the strength of ISFC shifts along the hierarchical organization of the brain. Primary sensory cortices appear to have strong inter-subject functional correlation, consistent with their role in processing exogenous information, while heteromodal regions that attend to endogenous processes have low inter-subject functional correlation. Those brain systems with higher intrinsic tendency show greater inter-individual variability, likely reflecting the aspects of brain connectivity architecture unique to individuals. Our study presents a novel framework for dissecting extrinsically- and intrinsically-driven processes, as well as examining individual differences in brain function during naturalistic stimulation.

  4. Hierarchical distance-based fuzzy approach to evaluate urban water supply systems in a semi-arid region.

    PubMed

    Yekta, Tahereh Sadeghi; Khazaei, Mohammad; Nabizadeh, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Yari, Ahmad Reza

    2015-01-01

    Hierarchical distance-based fuzzy multi-criteria group decision making was served as a tool to evaluate the drinking water supply systems of Qom, a semi-arid city located in central part of Iran. A list of aspects consisting of 6 criteria and 35 sub-criteria were evaluated based on a linguistic term set by five decision-makers. Four water supply alternatives including "Public desalinated distribution system", "PET Bottled Drinking Water", "Private desalinated water suppliers" and "Household desalinated water units" were assessed based on criteria and sub-criteria. Data were aggregated and normalized to apply Performance Ratings of Alternatives. Also, the Performance Ratings of Alternatives were aggregated again to achieve the Aggregate Performance Ratings. The weighted distances from ideal solution and anti-ideal solution were calculated after secondary normalization. The proximity of each alternative to the ideal solution was determined as the final step. The alternatives were ranked based on the magnitude of ideal solutions. Results showed that "Public desalinated distribution system" was the most appropriate alternative to supply the drinking needs of Qom population. Also, "PET Bottled Drinking Water" was the second acceptable option. A novel classification of alternatives to satisfy the drinking water requirements was proposed which is applicable for the other cities located in semi-arid regions of Iran. The health issues were considered as independent criterion, distinct from the environmental issues. The constraints of high-tech alternatives were also considered regarding to the level of dependency on overseas.

  5. Method and system of integrating information from multiple sources

    DOEpatents

    Alford, Francine A.; Brinkerhoff, David L.

    2006-08-15

    A system and method of integrating information from multiple sources in a document centric application system. A plurality of application systems are connected through an object request broker to a central repository. The information may then be posted on a webpage. An example of an implementation of the method and system is an online procurement system.

  6. Multiple IMU system development, volume 1

    NASA Technical Reports Server (NTRS)

    Landey, M.; Mckern, R.

    1974-01-01

    A redundant gimballed inertial system is described. System requirements and mechanization methods are defined and hardware and software development is described. Failure detection and isolation algorithms are presented and technology achievements described. Application of the system as a test tool for shuttle avionics concepts is outlined.

  7. Distributed PACS using distributed file system with hierarchical meta data servers.

    PubMed

    Hiroyasu, Tomoyuki; Minamitani, Yoshiyuki; Miki, Mitsunori; Yokouchi, Hisatake; Yoshimi, Masato

    2012-01-01

    In this research, we propose a new distributed PACS (Picture Archiving and Communication Systems) which is available to integrate several PACSs that exist in each medical institution. The conventional PACS controls DICOM file into one data-base. On the other hand, in the proposed system, DICOM file is separated into meta data and image data and those are stored individually. Using this mechanism, since file is not always accessed the entire data, some operations such as finding files, changing titles, and so on can be performed in high-speed. At the same time, as distributed file system is utilized, accessing image files can also achieve high-speed access and high fault tolerant. The introduced system has a more significant point. That is the simplicity to integrate several PACSs. In the proposed system, only the meta data servers are integrated and integrated system can be constructed. This system also has the scalability of file access with along to the number of file numbers and file sizes. On the other hand, because meta-data server is integrated, the meta data server is the weakness of this system. To solve this defect, hieratical meta data servers are introduced. Because of this mechanism, not only fault--tolerant ability is increased but scalability of file access is also increased. To discuss the proposed system, the prototype system using Gfarm was implemented. For evaluating the implemented system, file search operating time of Gfarm and NFS were compared.

  8. Organization of Excitable Dynamics in Hierarchical Biological Networks

    PubMed Central

    Müller-Linow, Mark; Hilgetag, Claus C.; Hütt, Marc-Thorsten

    2008-01-01

    This study investigates the contributions of network topology features to the dynamic behavior of hierarchically organized excitable networks. Representatives of different types of hierarchical networks as well as two biological neural networks are explored with a three-state model of node activation for systematically varying levels of random background network stimulation. The results demonstrate that two principal topological aspects of hierarchical networks, node centrality and network modularity, correlate with the network activity patterns at different levels of spontaneous network activation. The approach also shows that the dynamic behavior of the cerebral cortical systems network in the cat is dominated by the network's modular organization, while the activation behavior of the cellular neuronal network of Caenorhabditis elegans is strongly influenced by hub nodes. These findings indicate the interaction of multiple topological features and dynamic states in the function of complex biological networks. PMID:18818769

  9. A multiple-input multiple-output system for modeling the cardiac dynamics.

    PubMed

    Monzon, Jorge E; Picaza, Carlos Alvarez; Pisarello, Maria I

    2011-01-01

    We describe the dynamics of the cardiovascular system by finding the input-output relationships in the state space of a functional cardiac model, based on state equations and observability criteria of control theory. The unit step response of the multiple-input multiple-output system model illustrates the damping effect of the arterial wall to the pulsatility of the heart. Our results show that hypertensive patients exhibit a lower inertia of the blood flow.

  10. Modernization of the multiple launch rocket system embedded system software

    NASA Astrophysics Data System (ADS)

    Mockensturm, Jeffrey J.

    1995-03-01

    Weapon systems in the Department of Defense (DOD) are becoming increasingly reliant on embedded software. As the size and level of complexity of these software development efforts have increased, the management of these programs has become more challenging. Additionally, as the Army strives to digitize the future battlefield, the demand for software will only increase. This thesis reviews the software development efforts associated with modernizing the Army's Multiple Launch Rocket System (MLRS). The thesis begins by presenting a background discussion of the Army's Fire Direction Data Manager (FDDM) development. After the FDDM background discussion, a case study of the troubled FDDM software development effort is presented. The FDDM case study follows the general format presented in the May 1992 General Accounting Office report on the FDDM software development difficulties. Following the FDDM review, the current MLRS software development effort, the Improved Fire Control System (IFCS), is presented. Next, the FDDM case study is reviewed to determine the software development lessons learned. Using the FDDM software lessons learned, the IFCS program is analyzed to determine the software risks, and to review the risk mitigation strategies of that program. The objective of the thesis is to provide insight into the use of modern software management methods in reducing software development program risk.

  11. Dynamical configurations of celestial systems comprised of multiple irregular bodies

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Zhang, Yun; Baoyin, Hexi; Li, Junfeng

    2016-09-01

    This manuscript considers the main features of the nonlinear dynamics of multiple irregular celestial body systems. The gravitational potential, static electric potential, and magnetic potential are considered. Based on the three established potentials, we show that three conservative values exist for this system, including a Jacobi integral. The equilibrium conditions for the system are derived and their stability analyzed. The equilibrium conditions of a celestial system comprised of n irregular bodies are reduced to 12n - 9 equations. The dynamical results are applied to simulate the motion of multiple-asteroid systems. The simulation is useful for the study of the stability of multiple irregular celestial body systems and for the design of spacecraft orbits to triple-asteroid systems discovered in the solar system. The dynamical configurations of the five triple-asteroid systems 45 Eugenia, 87 Sylvia, 93 Minerva, 216 Kleopatra, and 136617 1994CC, and the six-body system 134340 Pluto are calculated and analyzed.

  12. Multiple system modelling of waste management.

    PubMed

    Eriksson, Ola; Bisaillon, Mattias

    2011-12-01

    Due to increased environmental awareness, planning and performance of waste management has become more and more complex. Therefore waste management has early been subject to different types of modelling. Another field with long experience of modelling and systems perspective is energy systems. The two modelling traditions have developed side by side, but so far there are very few attempts to combine them. Waste management systems can be linked together with energy systems through incineration plants. The models for waste management can be modelled on a quite detailed level whereas surrounding systems are modelled in a more simplistic way. This is a problem, as previous studies have shown that assumptions on the surrounding system often tend to be important for the conclusions. In this paper it is shown how two models, one for the district heating system (MARTES) and another one for the waste management system (ORWARE), can be linked together. The strengths and weaknesses with model linking are discussed when compared to simplistic assumptions on effects in the energy and waste management systems. It is concluded that the linking of models will provide a more complete, correct and credible picture of the consequences of different simultaneous changes in the systems. The linking procedure is easy to perform and also leads to activation of project partners. However, the simulation procedure is a bit more complicated and calls for the ability to run both models.

  13. The ability of the auditory system to cope with temporal subsampling depends on the hierarchical level of processing.

    PubMed

    Zoefel, Benedikt; Reddy Pasham, Naveen; Brüers, Sasskia; VanRullen, Rufin

    2015-09-09

    Evidence for rhythmic or 'discrete' sensory processing is abundant for the visual system, but sparse and inconsistent for the auditory system. Fundamental differences in the nature of visual and auditory inputs might account for this discrepancy: whereas the visual system mainly relies on spatial information, time might be the most important factor for the auditory system. In contrast to vision, temporal subsampling (i.e. taking 'snapshots') of the auditory input stream might thus prove detrimental for the brain as essential information would be lost. Rather than embracing the view of a continuous auditory processing, we recently proposed that discrete 'perceptual cycles' might exist in the auditory system, but on a hierarchically higher level of processing, involving temporally more stable features. This proposal leads to the prediction that the auditory system would be more robust to temporal subsampling when applied on a 'high-level' decomposition of auditory signals. To test this prediction, we constructed speech stimuli that were subsampled at different frequencies, either at the input level (following a wavelet transform) or at the level of auditory features (on the basis of LPC vocoding), and presented them to human listeners. Auditory recognition was significantly more robust to subsampling in the latter case, that is on a relatively high level of auditory processing. Although our results do not directly demonstrate perceptual cycles in the auditory domain, they (a) show that their existence is possible without disrupting temporal information to a critical extent and (b) confirm our proposal that, if they do exist, they should operate on a higher level of auditory processing.

  14. From Clouds to Protostars: A Theoretical Framework for the Formation of Wide Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Offner, Stella

    The majority of stars reside in binary or multiple star systems. Binary formation is determined largely during the earliest stages of star formation, when star forming cores are highly obscured and difficult to probe at high resolution. Exactly why some cores form a single star, while others form a multiple star system, is not understood. The goal of this proposal is to study the physics responsible for stellar multiplicity, with a specific focus on understanding the formation of wide multiple star systems. Theories for binary formation and their properties have strong relevance to NASA science objectives, especially for the Spitzer, Kepler, and JWST missions. Understanding binary formation is crucial for modeling many phenomena that rely on binary properties, ranging from reionization to planet formation. A number of current and planned large-scale surveys aim to probe starless and protostellar cores down to resolutions of approximately 200 AU. These surveys reinforce the timeliness of this project and underscore the pressing need for a predictive and general framework for understanding core fragmentation and the relation between multiplicity and physical conditions. Recently, the PI and co-I have demonstrated that dimensionless parameters can be used in combination with numerical simulations to describe core evolution for (non-idealized) turbulent, non-isothermal cores. They have used simulations to test a new method for characterizing hierarchical structure, which is ideal for identifying and analyzing cores and their incipient substructure. This proposal aims to extend the previous work by running a suite of high-resolution, magneto-hydrodynamic simulations of star-forming molecular clouds. The proposers will then develop an algorithm to track structure (e.g., cores and filaments) as a function of time and assess how well fundamental physical parameters, such as rotational energy, mass-to-flux ratio, and virial parameter, are predictive of stellar multiplicity

  15. Proportion of general factor variance in a hierarchical multiple-component measuring instrument: a note on a confidence interval estimation procedure.

    PubMed

    Raykov, Tenko; Zinbarg, Richard E

    2011-05-01

    A confidence interval construction procedure for the proportion of explained variance by a hierarchical, general factor in a multi-component measuring instrument is outlined. The method provides point and interval estimates for the proportion of total scale score variance that is accounted for by the general factor, which could be viewed as common to all components. The approach may also be used for testing composite (one-tailed) or simple hypotheses about this proportion, and is illustrated with a pair of examples.

  16. Multiple system modelling of waste management

    SciTech Connect

    Eriksson, Ola; Bisaillon, Mattias

    2011-12-15

    Highlights: > Linking of models will provide a more complete, correct and credible picture of the systems. > The linking procedure is easy to perform and also leads to activation of project partners. > The simulation procedure is a bit more complicated and calls for the ability to run both models. - Abstract: Due to increased environmental awareness, planning and performance of waste management has become more and more complex. Therefore waste management has early been subject to different types of modelling. Another field with long experience of modelling and systems perspective is energy systems. The two modelling traditions have developed side by side, but so far there are very few attempts to combine them. Waste management systems can be linked together with energy systems through incineration plants. The models for waste management can be modelled on a quite detailed level whereas surrounding systems are modelled in a more simplistic way. This is a problem, as previous studies have shown that assumptions on the surrounding system often tend to be important for the conclusions. In this paper it is shown how two models, one for the district heating system (MARTES) and another one for the waste management system (ORWARE), can be linked together. The strengths and weaknesses with model linking are discussed when compared to simplistic assumptions on effects in the energy and waste management systems. It is concluded that the linking of models will provide a more complete, correct and credible picture of the consequences of different simultaneous changes in the systems. The linking procedure is easy to perform and also leads to activation of project partners. However, the simulation procedure is a bit more complicated and calls for the ability to run both models.

  17. Integrated systems analysis of sow replacement rates in a hierarchical swine breeding structure.

    PubMed

    Faust, M A; Robison, O W; Tess, M W

    1993-11-01

    Sow replacement rates in a three-tiered breeding structure were investigated for a 10-yr planning horizon using a stochastic life-cycle swine production model. Market hogs were produced in a three-breed static crossing program and marketed on a liveweight basis. Growth and reproductive traits of individual pigs were simulated using genetic, environmental, and economic parameters. Sows were culled after a maximum of 1, 5, or 10 parities. Systems were defined by maximum sow age at culling and included combinations of 1- and 5-parity nucleus and 1-, 5-, and 10-parity multiplier and commercial tiers. Economic response to index selection was considerable for all culling alternatives with yearly increases in system profits ranging from $1.06 to 1.44 for each commercial hog marketed. When sows were culled after one parity in nucleus, multiplier, and commercial tiers, respectively (1,1,1), annual changes in net returns and all cost measures were 40 to 50% larger than responses in systems with lower sow replacement rates. Based on 10-yr averages for net returns, systems with low multiplier- and commercial-level replacement rates were more profitable than systems with higher replacement rates. The most profitable system (5,10,10) differed from the least profitable system (1,1,1) by more than $10 per pig, but when the (1,1,1) system was excluded, the range was only $3 per pig. The system with lowest replacement rates supported 3,388 more multiplier and 34,151 more commercial sows from a 750-sow nucleus level than the (1,1,1) system. Output from the two extremes differed by > 664,000 commercial market hogs sold.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Belt-hierarchic structure of th ring, satellite and planet systems: prediction S/2001 U1 and others objects in Solar system

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.

    2003-04-01

    BELT-HIERARCHIC STRUCTURE OF THE RING, SATELLITE AND PLANET SYSTEMS: PREDICTION S/2001 U1 AND OTHERS OBJECTS IN SOLAR SYSTEM Yu.V.Barkin Sternberg Astronomical Institute, Moscow, Russia, barkin@sai.msu.ru Structure regularities of the planet and satellite systems have been studied. Statistic analysis of the distribution of the major semi-axes of the orbits of the planets, comets and centaurs of the Solar system, satellite and ring systems of Jupiter, Saturn, Neptune and Uran, exoplanet systems of the pulsars PSR 1257+12, PSR 1828-11 and of the main consequence star Ups And was fulfilled. The following empirical regularities were described [1]: 1) the bodies of systems are combined into hierarchic groups and main from them combine 5 companions; 2) differences of the major semi-axes of the neighboring orbits for bodies of every group are constant; 4) for main neighboring hierarchic group these distances are distinguished in 6 times increasing to external grope; 5) the filling of the gropes and some present changes in their structure are caused by the past catastrophes in corresponding systems. The special method of reconstruction of the catastrophes which had place in the life of the Solar system (SS) was developed. Suggested method has let us to explain uniformly observed values of the major semi-axes and average values of eccentricities of the planets. In particular the Pancul’s hypothesis about Jupiter formation from two giant protoplanets (Jupiter I and Jupiter II) was confirmed. The new empirical law of the filling of the orbits of the regular groups of the planets or satellites (or rings structures) of the hierarchic ordered systems of celestial bodies was established. It was shown that sum number of bodies is proportional to the value of catastrophic value of the eccentricities which are same for first, second ,.... and fifth orbits of all gropes. The theoretical numbers of bodies for pointed orbits practically coincide with their observed numbers in main

  19. Supporting multiple control systems at Fermilab

    SciTech Connect

    Nicklaus, Dennis J.; /Fermilab

    2009-10-01

    The Fermilab control system, ACNET, is used for controlling the Tevatron and all of its pre-accelerators. However, other smaller experiments at Fermilab have been using different controls systems, in particular DOOCS and EPICS. This paper reports some of the steps taken at Fermilab to integrate support for these outside systems. We will describe specific tools that we have built or adapted to facilitate interaction between the architectures. We also examine some of the difficulties that arise from managing this heterogeneous environment. Incompatibilities as well as common elements will be described.

  20. Seismic isolation systems with distinct multiple frequencies

    DOEpatents

    Wu, Ting-shu; Seidensticker, Ralph W.

    1990-01-01

    A method and apparatus for isolating a building or other structure from smic vibratory motion which provides increased assurance that large horizontal motion of the structure will not occur than is provided by other isolation systems. Increased assurance that large horizontal motion will not occur is achieved by providing for change of the natural frequency of the support and structure system in response to displacement of the structure beyond a predetermined value. The natural frequency of the support and structure system may be achieved by providing for engaging and disengaging of the structure and some supporting members in response to motion of the supported structure.

  1. Analysis of bilinear stochastic systems. [involving multiplicative noise processes

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.; Marcus, S. I.; Martin, D. N.

    1974-01-01

    Analysis of stochastic dynamical systems that involve multiplicative (bilinear) noise processes is considered. After defining the systems of interest, the evolution of the moments of such systems, the question of stochastic stability, and estimation for bilinear stochastic systems are discussed. Both exact and approximate methods of analysis are introduced, and, in particular, the uses of Lie-theoretic concepts and harmonic analysis are discussed.

  2. Adaptable Transponder for Multiple Telemetry Systems

    NASA Technical Reports Server (NTRS)

    Sims, William Herbert, III (Inventor); Varnavas, Kosta A. (Inventor)

    2014-01-01

    The present invention is a stackable telemetry circuit board for use in telemetry systems for satellites and other purposes. The present invention incorporates previously-qualified interchangeable circuit boards, or "decks," that perform functions such as power, signal receiving and transmission, and processing. Each deck is adapted to serve a range of telemetry applications. This provides flexibility in the construction of the stackable telemetry circuit board and significantly reduces the cost and time necessary to develop a telemetry system.

  3. Switched Systems With Multiple Invariant Sets

    DTIC Science & Technology

    2015-05-06

    system. The resulting construction is slightly more complicated, as we consider V̇ in order to isolate the invariant sets rather than using the Lyapunov ...switched systems literature are both Lyapunov -based, and we will make use of Lyapunov functions to define all the relevant sets. The benefit to relying on... Lyapunov functions is that this requires no special structure on the subsystems’ entire vector fields. The tradeoff is that we fail to exploit any

  4. Multiple Drosophila Tracking System with Heading Direction

    PubMed Central

    Sirigrivatanawong, Pudith; Arai, Shogo; Thoma, Vladimiros; Hashimoto, Koichi

    2017-01-01

    Machine vision systems have been widely used for image analysis, especially that which is beyond human ability. In biology, studies of behavior help scientists to understand the relationship between sensory stimuli and animal responses. This typically requires the analysis and quantification of animal locomotion. In our work, we focus on the analysis of the locomotion of the fruit fly Drosophila melanogaster, a widely used model organism in biological research. Our system consists of two components: fly detection and tracking. Our system provides the ability to extract a group of flies as the objects of concern and furthermore determines the heading direction of each fly. As each fly moves, the system states are refined with a Kalman filter to obtain the optimal estimation. For the tracking step, combining information such as position and heading direction with assignment algorithms gives a successful tracking result. The use of heading direction increases the system efficiency when dealing with identity loss and flies swapping situations. The system can also operate with a variety of videos with different light intensities. PMID:28067800

  5. Resilient 3D hierarchical architected metamaterials.

    PubMed

    Meza, Lucas R; Zelhofer, Alex J; Clarke, Nigel; Mateos, Arturo J; Kochmann, Dennis M; Greer, Julia R

    2015-09-15

    Hierarchically designed structures with architectural features that span across multiple length scales are found in numerous hard biomaterials, like bone, wood, and glass sponge skeletons, as well as manmade structures, like the Eiffel Tower. It has been hypothesized that their mechanical robustness and damage tolerance stem from sophisticated ordering within the constituents, but the specific role of hierarchy remains to be fully described and understood. We apply the principles of hierarchical design to create structural metamaterials from three material systems: (i) polymer, (ii) hollow ceramic, and (iii) ceramic-polymer composites that are patterned into self-similar unit cells in a fractal-like geometry. In situ nanomechanical experiments revealed (i) a nearly theoretical scaling of structural strength and stiffness with relative density, which outperforms existing nonhierarchical nanolattices; (ii) recoverability, with hollow alumina samples recovering up to 98% of their original height after compression to ≥ 50% strain; (iii) suppression of brittle failure and structural instabilities in hollow ceramic hierarchical nanolattices; and (iv) a range of deformation mechanisms that can be tuned by changing the slenderness ratios of the beams. Additional levels of hierarchy beyond a second order did not increase the strength or stiffness, which suggests the existence of an optimal degree of hierarchy to amplify resilience. We developed a computational model that captures local stress distributions within the nanolattices under compression and explains some of the underlying deformation mechanisms as well as validates the measured effective stiffness to be interpreted as a metamaterial property.

  6. Resilient 3D hierarchical architected metamaterials

    PubMed Central

    Meza, Lucas R.; Zelhofer, Alex J.; Clarke, Nigel; Mateos, Arturo J.; Kochmann, Dennis M.; Greer, Julia R.

    2015-01-01

    Hierarchically designed structures with architectural features that span across multiple length scales are found in numerous hard biomaterials, like bone, wood, and glass sponge skeletons, as well as manmade structures, like the Eiffel Tower. It has been hypothesized that their mechanical robustness and damage tolerance stem from sophisticated ordering within the constituents, but the specific role of hierarchy remains to be fully described and understood. We apply the principles of hierarchical design to create structural metamaterials from three material systems: (i) polymer, (ii) hollow ceramic, and (iii) ceramic–polymer composites that are patterned into self-similar unit cells in a fractal-like geometry. In situ nanomechanical experiments revealed (i) a nearly theoretical scaling of structural strength and stiffness with relative density, which outperforms existing nonhierarchical nanolattices; (ii) recoverability, with hollow alumina samples recovering up to 98% of their original height after compression to ≥50% strain; (iii) suppression of brittle failure and structural instabilities in hollow ceramic hierarchical nanolattices; and (iv) a range of deformation mechanisms that can be tuned by changing the slenderness ratios of the beams. Additional levels of hierarchy beyond a second order did not increase the strength or stiffness, which suggests the existence of an optimal degree of hierarchy to amplify resilience. We developed a computational model that captures local stress distributions within the nanolattices under compression and explains some of the underlying deformation mechanisms as well as validates the measured effective stiffness to be interpreted as a metamaterial property. PMID:26330605

  7. Software simulator for multiple computer simulation system

    NASA Technical Reports Server (NTRS)

    Ogrady, E. P.

    1983-01-01

    A description is given of the structure and use of a computer program that simulates the operation of a parallel processor simulation system. The program is part of an investigation to determine algorithms that are suitable for simulating continous systems on a parallel processor configuration. The simulator is designed to accurately simulate the problem-solving phase of a simulation study. Care has been taken to ensure the integrity and correctness of data exchanges and to correctly sequence periods of computation and periods of data exchange. It is pointed out that the functions performed during a problem-setup phase or a reset phase are not simulated. In particular, there is no attempt to simulate the downloading process that loads object code into the local, transfer, and mapping memories of processing elements or the memories of the run control processor and the system control processor. The main program of the simulator carries out some problem-setup functions of the system control processor in that it requests the user to enter values for simulation system parameters and problem parameters. The method by which these values are transferred to the other processors, however, is not simulated.

  8. Bayesian system identification based on hierarchical sparse Bayesian learning and Gibbs sampling with application to structural damage assessment

    NASA Astrophysics Data System (ADS)

    Huang, Yong; Beck, James L.; Li, Hui

    2017-05-01

    The focus in this paper is Bayesian system identification based on noisy incomplete modal data where we can impose spatially-sparse stiffness changes when updating a structural model. To this end, based on a similar hierarchical sparse Bayesian learning model from our previous work, we propose two Gibbs sampling algorithms. The algorithms differ in their strategies to deal with the posterior uncertainty of the equation-error precision parameter, but both sample from the conditional posterior probability density functions (PDFs) for the structural stiffness parameters and system modal parameters. The effective dimension for the Gibbs sampling is low because iterative sampling is done from only three conditional posterior PDFs that correspond to three parameter groups, along with sampling of the equation-error precision parameter from another conditional posterior PDF in one of the algorithms where it is not integrated out as a "nuisance" parameter. A nice feature from a computational perspective is that it is not necessary to solve a nonlinear eigenvalue problem of a structural model. The effectiveness and robustness of the proposed algorithms are illustrated by applying them to the IASE-ASCE Phase II simulated and experimental benchmark studies. The goal is to use incomplete modal data identified before and after possible damage to detect and assess spatially-sparse stiffness reductions induced by any damage. Our past and current focus on meeting challenges arising from Bayesian inference of structural stiffness serve to strengthen the capability of vibration-based structural system identification but our methods also have much broader applicability for inverse problems in science and technology where system matrices are to be inferred from noisy partial information about their eigenquantities.

  9. An Expert System for Diagnosing Children's Multiplication Errors.

    ERIC Educational Resources Information Center

    Attisha, M.; Yazdani, M.

    1984-01-01

    Describes a microcomputer-based system for diagnosing children's multiplication errors which incorporates the knowledge base of all known systematic multiplication errors, and utilizes a modular approach to cope with the program's complexity. Each module's function, how the programs interact, and the design of pupil-machine interaction are…

  10. A Decision Support System for Solving Multiple Criteria Optimization Problems

    ERIC Educational Resources Information Center

    Filatovas, Ernestas; Kurasova, Olga

    2011-01-01

    In this paper, multiple criteria optimization has been investigated. A new decision support system (DSS) has been developed for interactive solving of multiple criteria optimization problems (MOPs). The weighted-sum (WS) approach is implemented to solve the MOPs. The MOPs are solved by selecting different weight coefficient values for the criteria…

  11. Multiple strategies of reasoning for expert systems

    SciTech Connect

    Yao Yuchuan; Kulikowski, C.A.

    1983-01-01

    In expert systems the heuristics used for combining the weight of evidence can be based on probabilistic, fuzzy set, or subjective confidence factors. Although the underlying assumptions for each of the methods differ, it can be shown that there are correspondences between them and that it is possible to develop a model of expert reasoning for medical consultation using any one of the methods. The authors have developed a system for representing expert knowledge, called ESMES, which is an outgrowth of the expert scheme developed earlier at Rutgers. ESMES allows the use of alternative strategies in the solution of a consultation problem. The authors report on the performance of ESMES for a prototype glaucoma consultation model, using reasoning mechanisms similar to those of the expert, MYCIN, Internist I, and Prospector systems. 9 references.

  12. An adaptive, self-organizing dynamical system for hierarchical control of bio-inspired locomotion.

    PubMed

    Arena, Paolo; Fortuna, Luigi; Frasca, Mattia; Sicurella, Giovanni

    2004-08-01

    In this paper, dynamical systems made up of locally coupled nonlinear units are used to control the locomotion of bio-inspired robots and, in particular, a simulation of an insect-like hexapod robot. These controllers are inspired by the biological paradigm of central pattern generators and are responsible for generating a locomotion gait. A general structure, which is able to change the locomotion gait according to environmental conditions, is introduced. This structure is based on an adaptive system, implemented by motor maps, and is able to learn the correct locomotion gait on the basis of a reward function. The proposed control system is validated by a large number of simulations carried out in a dynamic environment for simulating legged robots.

  13. Scheduling A Multiple Operating Room System

    PubMed Central

    Barnoon, Shlomo; Wolfe, Harvey

    1968-01-01

    The advantages and disadvantages of various schedules for operating rooms are determined by the use of a Simscript simulation program. Input variables consist of actual data or are generated from their probability distributions by the Monte Carlo technique. The simulator assigns operating rooms, anesthetists, and nurses for each case when they are available. A report of the performance of the system, which may be obtained at any desired periodic cycle, includes idle time and waiting time for facilities and personnel. The simulator, applied here to a suite of operating rooms in a specialty hospital for elective surgery, can, with minor modifications, be used to describe a general system of operating rooms. PMID:5700370

  14. An efficient key-management scheme for hierarchical access control in e-medicine system.

    PubMed

    Wu, Shuhua; Chen, Kefei

    2012-08-01

    In e-medicine system, the sharing of patients' medical histories scattered among medical institutions through the Internet is highly desirable. The most immediate cryptographic need certainly is an efficient key management method to solve dynamic access problems in a user hierarchy. In this paper, we propose a practical solution for dynamic access problem in a user hierarchy based on hybrid cryptosystems. When compared with Nikooghadam et al.'s scheme proposed most recently, the time complexity and the required storage space is reduced significantly. Moreover, it provides provable security, and is easy to implement. Therefore, our scheme is more suitable for e-medicine system.

  15. Remarks on Hierarchic Control for a Linearized Micropolar Fluids System in Moving Domains

    SciTech Connect

    Jesus, Isaías Pereira de

    2015-12-15

    We study a Stackelberg strategy subject to the evolutionary linearized micropolar fluids equations in domains with moving boundaries, considering a Nash multi-objective equilibrium (non necessarily cooperative) for the “follower players” (as is called in the economy field) and an optimal problem for the leader player with approximate controllability objective. We will obtain the following main results: the existence and uniqueness of Nash equilibrium and its characterization, the approximate controllability of the linearized micropolar system with respect to the leader control and the existence and uniqueness of the Stackelberg–Nash problem, where the optimality system for the leader is given.

  16. Development and application of a real-time testbed for multiagent system interoperability: A case study on hierarchical microgrid control

    SciTech Connect

    Cintuglu, Mehmet Hazar; Youssef, Tarek; Mohammed, Osama A.

    2016-08-10

    This article presents the development and application of a real-time testbed for multiagent system interoperability. As utility independent private microgrids are installed constantly, standardized interoperability frameworks are required to define behavioral models of the individual agents for expandability and plug-and-play operation. In this paper, we propose a comprehensive hybrid agent framework combining the foundation for intelligent physical agents (FIPA), IEC 61850, and data distribution service (DDS) standards. The IEC 61850 logical node concept is extended using FIPA based agent communication language (ACL) with application specific attributes and deliberative behavior modeling capability. The DDS middleware is adopted to enable a real-time publisher-subscriber interoperability mechanism between platforms. The proposed multi-agent framework was validated in a laboratory based testbed involving developed intelligent electronic device (IED) prototypes and actual microgrid setups. Experimental results were demonstrated for both decentralized and distributed control approaches. Secondary and tertiary control levels of a microgrid were demonstrated for decentralized hierarchical control case study. A consensus-based economic dispatch case study was demonstrated as a distributed control example. Finally, it was shown that the developed agent platform is industrially applicable for actual smart grid field deployment.

  17. Development and application of a real-time testbed for multiagent system interoperability: A case study on hierarchical microgrid control

    DOE PAGES

    Cintuglu, Mehmet Hazar; Youssef, Tarek; Mohammed, Osama A.

    2016-08-10

    This article presents the development and application of a real-time testbed for multiagent system interoperability. As utility independent private microgrids are installed constantly, standardized interoperability frameworks are required to define behavioral models of the individual agents for expandability and plug-and-play operation. In this paper, we propose a comprehensive hybrid agent framework combining the foundation for intelligent physical agents (FIPA), IEC 61850, and data distribution service (DDS) standards. The IEC 61850 logical node concept is extended using FIPA based agent communication language (ACL) with application specific attributes and deliberative behavior modeling capability. The DDS middleware is adopted to enable a real-timemore » publisher-subscriber interoperability mechanism between platforms. The proposed multi-agent framework was validated in a laboratory based testbed involving developed intelligent electronic device (IED) prototypes and actual microgrid setups. Experimental results were demonstrated for both decentralized and distributed control approaches. Secondary and tertiary control levels of a microgrid were demonstrated for decentralized hierarchical control case study. A consensus-based economic dispatch case study was demonstrated as a distributed control example. Finally, it was shown that the developed agent platform is industrially applicable for actual smart grid field deployment.« less

  18. Development and application of a real-time testbed for multiagent system interoperability: A case study on hierarchical microgrid control

    SciTech Connect

    Cintuglu, Mehmet Hazar; Youssef, Tarek; Mohammed, Osama A.

    2016-08-10

    This article presents the development and application of a real-time testbed for multiagent system interoperability. As utility independent private microgrids are installed constantly, standardized interoperability frameworks are required to define behavioral models of the individual agents for expandability and plug-and-play operation. In this paper, we propose a comprehensive hybrid agent framework combining the foundation for intelligent physical agents (FIPA), IEC 61850, and data distribution service (DDS) standards. The IEC 61850 logical node concept is extended using FIPA based agent communication language (ACL) with application specific attributes and deliberative behavior modeling capability. The DDS middleware is adopted to enable a real-time publisher-subscriber interoperability mechanism between platforms. The proposed multi-agent framework was validated in a laboratory based testbed involving developed intelligent electronic device (IED) prototypes and actual microgrid setups. Experimental results were demonstrated for both decentralized and distributed control approaches. Secondary and tertiary control levels of a microgrid were demonstrated for decentralized hierarchical control case study. A consensus-based economic dispatch case study was demonstrated as a distributed control example. Finally, it was shown that the developed agent platform is industrially applicable for actual smart grid field deployment.

  19. In₂S₃/carbon nanofibers/Au ternary synergetic system: hierarchical assembly and enhanced visible-light photocatalytic activity.

    PubMed

    Zhang, Xin; Shao, Changlu; Li, Xinghua; Lu, Na; Wang, Kexin; Miao, Fujun; Liu, Yichun

    2015-01-01

    In this paper, carbon nanofibers (CNFs) were successfully synthesized by electrospinning technique. Next, Au nanoparticles (NPs) were assembled on the electrospun CNFs through in situ reduction method. By using the obtained Au NPs modified CNFs (CNFs/Au) as hard template, the In2S3/CNFs/Au composites were synthesized through hydrothermal technique. The results showed that the super long one-dimensional (1D) CNFs (about 306 nm in average diameter) were well connected to form a nanofibrous network; and, the Au NPs with 18 nm in average diameter and In2S3 nanosheets with 5-10nm in thickness were uniformly grown onto the surface of CNFs. Photocatalytic studies revealed that the In2S3/CNFs/Au composites exhibited highest visible-light photocatalytic activities for the degradation of Rhodamine B (RB) compared with pure In2S3 and In2S3/CNFs. The enhanced photocatalytic activity might arise from the high separation efficiency of photogenerated electron-hole pairs based on the positive synergetic effect between In2S3, CNFs and Au components in this ternary photocatalytic system. Meanwhile, the In2S3/CNFs/Au composites with hierarchical structure possess a strong adsorption ability towards organic dyes, which also contributed to the enhancement of photocatalytic activity. Moreover, the In2S3/CNFs/Au composites could be recycled easily by sedimentation due to their nanofibrous network structure.

  20. An intelligent decomposition approach for efficient design of non-hierarchic systems

    NASA Technical Reports Server (NTRS)

    Bloebaum, Christina L.

    1992-01-01

    The design process associated with large engineering systems requires an initial decomposition of the complex systems into subsystem modules which are coupled through transference of output data. The implementation of such a decomposition approach assumes the ability exists to determine what subsystems and interactions exist and what order of execution will be imposed during the analysis process. Unfortunately, this is quite often an extremely complex task which may be beyond human ability to efficiently achieve. Further, in optimizing such a coupled system, it is essential to be able to determine which interactions figure prominently enough to significantly affect the accuracy of the optimal solution. The ability to determine 'weak' versus 'strong' coupling strengths would aid the designer in deciding which couplings could be permanently removed from consideration or which could be temporarily suspended so as to achieve computational savings with minimal loss in solution accuracy. An approach that uses normalized sensitivities to quantify coupling strengths is presented. The approach is applied to a coupled system composed of analysis equations for verification purposes.

  1. Optoelectronic System Measures Distances to Multiple Targets

    NASA Technical Reports Server (NTRS)

    Liebe, Carl Christian; Abramovici, Alexander; Bartman, Randall; Chapsky, Jacob; Schmalz, John; Coste, Keith; Litty, Edward; Lam, Raymond; Jerebets, Sergei

    2007-01-01

    An optoelectronic metrology apparatus now at the laboratory-prototype stage of development is intended to repeatedly determine distances of as much as several hundred meters, at submillimeter accuracy, to multiple targets in rapid succession. The underlying concept of optoelectronic apparatuses that can measure distances to targets is not new; such apparatuses are commonly used in general surveying and machining. However, until now such apparatuses have been, variously, constrained to (1) a single target or (2) multiple targets with a low update rate and a requirement for some a priori knowledge of target geometry. When fully developed, the present apparatus would enable measurement of distances to more than 50 targets at an update rate greater than 10 Hz, without a requirement for a priori knowledge of target geometry. The apparatus (see figure) includes a laser ranging unit (LRU) that includes an electronic camera (photo receiver), the field of view of which contains all relevant targets. Each target, mounted at a fiducial position on an object of interest, consists of a small lens at the output end of an optical fiber that extends from the object of interest back to the LRU. For each target and its optical fiber, there is a dedicated laser that is used to illuminate the target via the optical fiber. The targets are illuminated, one at a time, with laser light that is modulated at a frequency of 10.01 MHz. The modulated laser light is emitted by the target, from where it returns to the camera (photodetector), where it is detected. Both the outgoing and incoming 10.01-MHz laser signals are mixed with a 10-MHz local-oscillator to obtain beat notes at 10 kHz, and the difference between the phases of the beat notes is measured by a phase meter. This phase difference serves as a measure of the total length of the path traveled by light going out through the optical fiber and returning to the camera (photodetector) through free space. Because the portion of the path

  2. Exoplanet orbital eccentricity: multiplicity relation and the Solar System.

    PubMed

    Limbach, Mary Anne; Turner, Edwin L

    2015-01-06

    The known population of exoplanets exhibits a much wider range of orbital eccentricities than Solar System planets and has a much higher average eccentricity. These facts have been widely interpreted to indicate that the Solar System is an atypical member of the overall population of planetary systems. We report here on a strong anticorrelation of orbital eccentricity with multiplicity (number of planets in the system) among cataloged radial velocity (RV) systems. The mean, median, and rough distribution of eccentricities of Solar System planets fits an extrapolation of this anticorrelation to the eight-planet case rather precisely despite the fact that no more than two Solar System planets would be detectable with RV data comparable to that in the exoplanet sample. Moreover, even if regarded as a single or double planetary system, the Solar System lies in a reasonably heavily populated region of eccentricity-multiplicity space. Thus, the Solar System is not anomalous among known exoplanetary systems with respect to eccentricities when its multiplicity is taken into account. Specifically, as the multiplicity of a system increases, the eccentricity decreases roughly as a power law of index -1.20. A simple and plausible but ad hoc and model-dependent interpretation of this relationship implies that ∼ 80% of the one-planet and 25% of the two-planet systems in our sample have additional, as yet undiscovered, members but that systems of higher observed multiplicity are largely complete (i.e., relatively rarely contain additional undiscovered planets). If low eccentricities indeed favor high multiplicities, habitability may be more common in systems with a larger number of planets.

  3. Exoplanet orbital eccentricity: Multiplicity relation and the Solar System

    PubMed Central

    Limbach, Mary Anne; Turner, Edwin L.

    2015-01-01

    The known population of exoplanets exhibits a much wider range of orbital eccentricities than Solar System planets and has a much higher average eccentricity. These facts have been widely interpreted to indicate that the Solar System is an atypical member of the overall population of planetary systems. We report here on a strong anticorrelation of orbital eccentricity with multiplicity (number of planets in the system) among cataloged radial velocity (RV) systems. The mean, median, and rough distribution of eccentricities of Solar System planets fits an extrapolation of this anticorrelation to the eight-planet case rather precisely despite the fact that no more than two Solar System planets would be detectable with RV data comparable to that in the exoplanet sample. Moreover, even if regarded as a single or double planetary system, the Solar System lies in a reasonably heavily populated region of eccentricity−multiplicity space. Thus, the Solar System is not anomalous among known exoplanetary systems with respect to eccentricities when its multiplicity is taken into account. Specifically, as the multiplicity of a system increases, the eccentricity decreases roughly as a power law of index –1.20. A simple and plausible but ad hoc and model-dependent interpretation of this relationship implies that ∼80% of the one-planet and 25% of the two-planet systems in our sample have additional, as yet undiscovered, members but that systems of higher observed multiplicity are largely complete (i.e., relatively rarely contain additional undiscovered planets). If low eccentricities indeed favor high multiplicities, habitability may be more common in systems with a larger number of planets. PMID:25512527

  4. Blind decorrelation and deconvolution algorithm for multiple-input multiple-output system: I. Theorem derivation

    NASA Astrophysics Data System (ADS)

    Yu, Tommy; Chen, Da-Ching; Pottie, Gregory J.; Yao, Kung

    1999-11-01

    The problems of blind decorrelation and blind deconvolution have attracted considerable interest recently. These two problems traditionally have been studied as two different subjects, and a variety of algorithms have been proposed to solve them. In this paper, we consider these two problems jointly in the application of a multi-sensor network and propose a new algorithm for them. In our model, the system is a MIMO system (multiple-input multiple-output) which consists of linearly independent FIR channels. The unknown inputs are assumed to be uncorrelated and persistently excited. Furthermore, inputs can be colored sources and their distributions can be unknown. The new algorithm is capable of separating multiple input sources passing through some dispersive channels. Our algorithm is a generalization of Moulines' algorithm from single input to multiple inputs. The new algorithm is based on second order statistics which require shorter data length than the higher order statistics algorithms for the same estimation accuracy.

  5. Hierarchical, decentralized control system for large-scale smart-structures

    NASA Astrophysics Data System (ADS)

    Algermissen, Stephan; Fröhlich, Tim; Monner, Hans Peter

    2014-08-01

    Active control of sound and vibration has gained much attention in all kinds of industries in the past decade. Future prospects for maximizing airline passenger comfort are especially promising. The objectives of recent research projects in this area are the reduction of noise transmission through thin walled structures such as fuselages, linings or interior elements. Besides different external noise sources, such as the turbulent boundary layer, rotor or jet noise, the actuator and sensor placement as well as different control concepts are addressed. Mostly, the work is focused on a single panel or section of the fuselage, neglecting the fact that for effective noise reduction the entire fuselage has to be taken into account. Nevertheless, extending the scope of an active system from a single panel to the entire fuselage increases the effort for control hardware dramatically. This paper presents a control concept for large structures using distributed control nodes. Each node has the capability to execute a vibration or noise controller for a specific part or section of the fuselage. For maintenance, controller tuning or performance measurement, all nodes are connected to a host computer via Universal Serial Bus (USB). This topology allows a partitioning and distributing of tasks. The nodes execute the low-level control functions. High-level tasks like maintenance, system identification and control synthesis are operated by the host using streamed data from the nodes. By choosing low-price nodes, a very cost effective way of implementing an active system for large structures is realized. Besides the system identification and controller synthesis on the host computer, a detailed view on the hardware and software concept for the nodes is given. Finally, the results of an experimental test of a system running a robust vibration controller at an active panel demonstrator are shown.

  6. Absolute stability for multiple delay general Lur'e control systems with multiple nonlinearities

    NASA Astrophysics Data System (ADS)

    He, Yong; Wu, Min

    2003-10-01

    In this paper, necessary and sufficient conditions are obtained for the existence of Lyapunov functional of extended Lur'e form to guarantee absolute stability for multiple delay general Lur'e control systems with multiple nonlinearities, and the existence reduces to a problem of solving a group of linear matrix inequalities (LMIs). When the LMIs are feasible, the free parameters in the Lyapunov functional are given by the solution of these LMIs. Otherwise, this class of Lyapunov functional does not exist.

  7. The Effect of Tidal Friction and Quadrupolar Distortion on Orbits of Stars or Planets in Hierarchical Triple systems

    NASA Astrophysics Data System (ADS)

    Kiseleva, L. G.; Eggleton, P. P.

    In hierarchical triple stars, such as lambda Tau and beta Per the combination of a) fluctuating eccentricity due to the third body and b) tidal friction, mainly within the close pair, which tries to remove such fluctuations, can lead to potentially large but slow secular changes in orbital parameters. We model the orbits of both the above systems using a force law which includes a combination of point-mass gravity, quadrupolar distortion of each star by the other two, and a dissipative tidal-friction term. For lambda Tau we find a preferred model where expansion of the inner orbit due to mass transfer on a nuclear timescale is balanced by contraction because tidal friction transfers angular momentum from the inner to the outer orbit. In beta Per, the two orbits are nearly orthogonal (i=100 deg), and the effect of the third star would periodically increase the inner eccentricity up to nearly unity if we neglect the effects of quadrupolar distortion and tidal friction. In fact, in beta Per quadrupolar distortion alone can almost completely suppress the inner eccenticity fluctuations. In a hypothetcal zero-age state of this system, when the inner binary can be supposed to be well-detached, we find large fluctuations in eccentricity which, on being damped by tidal friction, lead to shrinkage of the inner orbit on a surprisingly short timescale. However, the shrinkage is halted by the fact that as the inner pair becomes closer they become more distorted: this quadrupolar distortion leads to apsidal motion which prevents further large fluctuations in eccentricity. In hypothetical cases of nearly orthogonal triple systems with one component of the close pair being a Jupiter-like planet, the combined effect of quadrupolar distortion and tidal friction may reduce the fluctuations of the inner eccentricity, and in some cases the Jupiter orbit can in principle be shrunk quite drastically over a suitably long interval of time. This is potentially important for the long

  8. Regulation gel formation, hierarchical structures and surface wettability via isomeride effect in supramolecular organogel system.

    PubMed

    Cao, Xinhua; Ding, Qianqian; Gao, Aiping; Lv, Haiting; Zhao, Na; Liu, Dan

    2017-05-15

    A new serial of gelators with two cholesteryl groups based on o-phenylenediamine, m-phenylenediamine and p-phenylenediamine were synthesized, and their organogelation ability was evaluated. We found that G-o could form gels in DMF, DMSO and ethyl acetate, G-m and G-p could only gel DMF and 1,4-dioxane. The organogels were thoroughly characterized using various microscopic techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV-Vis spectrum, FT-IR spectrum and contact angle. The gelation ability, morphology, self-assembly mode and materials surface wettability all could be tuned via isomeride effect in self-assembly system. Interestingly, superhydrophobic surface was formed via the self-assembly of compound G-p in 1,4-dioxane and exhibited very high adsorption capacity for water. This gel system provided new method for modulation self-assembly process in supramolecular field.

  9. Multi-Sensor Systems: Multiplicity Helps

    DTIC Science & Technology

    2010-05-01

    constant, T0 is 290 K, B is the signal band- width, and L is the transmission loss . Each transmits-receive pair contributes to the overall system SNR... correlation signal processing techniques, to provide their location through the time difference of the received jammer waveform at each receiver [17]. A...incoherent networks are the simplest to fabricate but have the disadvantages of the lowest sensitivity, least flexibility and highest information loss

  10. Torsion system for creep testing with multiple stress reversals

    NASA Technical Reports Server (NTRS)

    Lilienthal, P. A.

    1969-01-01

    Torsion system proves exploratory data on accelerated creep due to multiple stress reversals. Torsional testing of tubular specimens is best suited for reversed stress creep tests since large strains are obtainable while maintaining specimen geometry.

  11. Scalable Hierarchical Network Management System for Displaying Network Information in Three Dimensions

    NASA Technical Reports Server (NTRS)

    George, Jude (Inventor); Schlecht, Leslie (Inventor); McCabe, James D. (Inventor); LeKashman, John Jr. (Inventor)

    1998-01-01

    A network management system has SNMP agents distributed at one or more sites, an input output module at each site, and a server module located at a selected site for communicating with input output modules, each of which is configured for both SNMP and HNMP communications. The server module is configured exclusively for HNMP communications, and it communicates with each input output module according to the HNMP. Non-iconified, informationally complete views are provided of network elements to aid in network management.

  12. Under-sampling in a Multiple-Channel Laser Vibrometry System

    SciTech Connect

    Corey, Jordan

    2007-03-01

    Laser vibrometry is a technique used to detect vibrations on objects using the interference of coherent light with itself. Most vibrometry systems process only one target location at a time, but processing multiple locations simultaneously provides improved detection capabilities. Traditional laser vibrometry systems employ oversampling to sample the incoming modulated-light signal, however as the number of channels increases in these systems, certain issues arise such a higher computational cost, excessive heat, increased power requirements, and increased component cost. This thesis describes a novel approach to laser vibrometry that utilizes undersampling to control the undesirable issues associated with over-sampled systems. Undersampling allows for significantly less samples to represent the modulated-light signals, which offers several advantages in the overall system design. These advantages include an improvement in thermal efficiency, lower processing requirements, and a higher immunity to the relative intensity noise inherent in laser vibrometry applications. A unique feature of this implementation is the use of a parallel architecture to increase the overall system throughput. This parallelism is realized using a hierarchical multi-channel architecture based on off-the-shelf programmable logic devices (PLDs).

  13. ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS

    SciTech Connect

    Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.; Bryson, Stephen T.; Howell, Steve B.; Ragozzine, Darin; Holman, Matthew J.; Carter, Joshua A.; Fabrycky, Daniel C.; Fortney, Jonathan J.; Steffen, Jason H.; Ford, Eric B.; Shporer, Avi; Rowe, Jason F.; Quintana, Elisa V.; Caldwell, Douglas A.; Ciardi, David; Gautier, Thomas N. III; and others

    2011-11-01

    About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.

  14. Enhancing traffic performance in hierarchical DHT system by exploiting network proximity

    NASA Astrophysics Data System (ADS)

    Zhong, Haifeng; Wu, Wei; Pei, Canhao; Zhang, Chengfeng

    2009-08-01

    Nowadays P2P systems have become increasingly popular for object distribution and file sharing, and the majority of Internet traffic is generated by P2P file sharing applications. However, those applications usually ignored the underlying proximity of physical nodes and regionalization of file accessing. As a result, they generate a large amount of unnecessary interdomain transit traffic and increase response latency. In this paper, we proposed a new traffic control approach to enhance p2p traffic locality and reduce the cross-group transfer. Using analysis, we show that the method substantially improves node transfer efficiency and significantly reduces file access latency compared with native P2P applications.

  15. MULTIPLE PROJECTIONS SYSTEM (MPS): USER'S MANUAL VERSION 2.0

    EPA Science Inventory

    The document is a user's manual for Multiple Projections System (MPS) Version 2.0, based on the 3% reasonable further progress (RFP) tracking system that was developed in FY92/FY93. The 3% RFP tracking system is a Windows application, and enhancements to convert the 3% RFP track...

  16. MULTIPLE PROJECTIONS SYSTEM (MPS): USER'S MANUAL VERSION 2.0

    EPA Science Inventory

    The document is a user's manual for Multiple Projections System (MPS) Version 2.0, based on the 3% reasonable further progress (RFP) tracking system that was developed in FY92/FY93. The 3% RFP tracking system is a Windows application, and enhancements to convert the 3% RFP track...

  17. DIATEST, A System for Programme Control of Multiple Choice Tests.

    ERIC Educational Resources Information Center

    Eriksson, Christer

    The DIATEST responder system is a control system for fully programed running of diagnostic tests of multiple-choice type. The system makes use of the control unit earlier developed at the Institute of Technology for programed four-screen slide projection and the electronic response analyser (ESAU). Presentation of a question is done audiovisually,…

  18. Advanced multiple access concepts in mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Ananasso, Fulvio

    1990-01-01

    Some multiple access strategies for Mobile Satellite Systems (MSS) are discussed. These strategies were investigated in the context of three separate studies conducted for the International Maritime Satellite Organization (INMARSAT) and the European Space Agency (ESA). Satellite-Switched Frequency Division Multiple Access (SS-FDMA), Code Division Multiple Access (CDMA), and Frequency-Addressable Beam architectures are addressed, discussing both system and technology aspects and outlining advantages and drawbacks of either solution with associated relevant hardware issues. An attempt is made to compare the considered option from the standpoint of user terminal/space segment complexity, synchronization requirements, spectral efficiency, and interference rejection.

  19. Realtime control of multiple sensor systems

    NASA Astrophysics Data System (ADS)

    Blankenship, Gilmer; Fletcher, Charles; Lavigna, Anthony

    1993-01-01

    The technical objectives of this project are the design and demonstration of methods for the optimal management of sensor systems. As a specific application, we consider the nonlinear filtering of a vector diffusion process, with several noisy vector observations. Any number of sensors can be utilized in the signal processing performed by the nonlinear filter. The problem considered is the optimal selection of a schedule of these sensors from the available set, so as to optimally estimate a function of the state at some given time. Solution of the optimal schedule is derived from solving a system of quasi-linear inequalities (QVI's). The schedule derived from these methods is optimal with respect to predetermined, but possibly varying, running and switching costs for the sensors, as well as some cost functional of the estimate of the dynamics. Methods include precise strategies for adapting the sensor configuration to the engagement at hand, including optimal timing of decisions to communicate or activate active sensors which reveal position. These strategies have been developed by TSI in the form of feedback control laws which are computationally efficient and simple to implement.

  20. The NP Draconii Multiple Star System

    NASA Astrophysics Data System (ADS)

    Castelaz, Michael W.; Barker, Thurburn; McNaughton, Abby; Robertson, Rachel; Smith, Matt

    2016-01-01

    Otero and Dubovsky used the ASAS-3 (Pojmanski 2002), Hipparcos (Perryman et al 1997) and Northern Sky Variability Survey (NSVS; Wozniak et al 2004) databases to determine elements for 80 eclipsing binaries. NP Draconii (NSV 22984) was identified by Otero and Dubovsky (IBVS Number 5557, 2004) as a possible Algol type variable with an ephemeris of HJD Min I = 2448604.780+3.10886E days based on 84 observations over 326 days with about 2 to 4 observations on any one night. We decided to further refine the ephemeris and observe NP Dra in VRI filters, with the goal of determining the elements of the system.NP Dra is a V = 9.0 system located at J2000 = 17h 35m 16s and +55d 00' 12". We observed NP Dra August 2, 3 and September 15, 16, 17, 18, and 19 2015 UT using the Pisgah Astronomical Research Institute 0.4-m telescope in V, R, and I with 20 second exposure times in each filter. Observations in each filter were repeated about every 3 minutes each night of observing.From our light curves we determined the period using the Date Compensated Discrete Fourier Transform function (Ferraz-Mello 1981) which is part of the open source code VSTAR (AAVSO). The period derived from the observations is 2.2755 days. Superimposed on this period is another period of 0.6398 days. We will present the V, R, and I light curves, period determination and implication

  1. On the detectability of long period perturbations in close hierarchical triple stellar systems

    NASA Astrophysics Data System (ADS)

    Borkovits, T.; Érdi, B.; Forgács-Dajka, E.; Kovács, T.

    2003-02-01

    We study the possibility of the detection of the low amplitude long (P') period perturbative effect of a distant third companion on the motion of a close binary. We give a new, more accurate analytical formula for this kind of perturbation affecting the moments of the times of minima in eclipsing binaries. The accuracy of this formula is tested by numerical integrations carried out for several initial configurations. We also describe a numerical method based on a non-linear Levenberg-Marquardt algorithm which makes it possible to separate this dynamical effect from the pure geometrical light-time effect in the eclipsing O-C diagram. The capabilities of this new method are demonstrated by the analysis of numerically simulated O-Cs for test systems having physical parameters very similar to Algol and IU Aur. The results show that the above mentioned effect would be detectable in these systems nowadays, observing almost each minima events in a 1-2 year-long interval.

  2. Associative Hierarchical Random Fields.

    PubMed

    Ladický, L'ubor; Russell, Chris; Kohli, Pushmeet; Torr, Philip H S

    2014-06-01

    This paper makes two contributions: the first is the proposal of a new model-The associative hierarchical random field (AHRF), and a novel algorithm for its optimization; the second is the application of this model to the problem of semantic segmentation. Most methods for semantic segmentation are formulated as a labeling problem for variables that might correspond to either pixels or segments such as super-pixels. It is well known that the generation of super pixel segmentations is not unique. This has motivated many researchers to use multiple super pixel segmentations for problems such as semantic segmentation or single view reconstruction. These super-pixels have not yet been combined in a principled manner, this is a difficult problem, as they may overlap, or be nested in such a way that the segmentations form a segmentation tree. Our new hierarchical random field model allows information from all of the multiple segmentations to contribute to a global energy. MAP inference in this model can be performed efficiently using powerful graph cut based move making algorithms. Our framework generalizes much of the previous work based on pixels or segments, and the resulting labelings can be viewed both as a detailed segmentation at the pixel level, or at the other extreme, as a segment selector that pieces together a solution like a jigsaw, selecting the best segments from different segmentations as pieces. We evaluate its performance on some of the most challenging data sets for object class segmentation, and show that this ability to perform inference using multiple overlapping segmentations leads to state-of-the-art results.

  3. Switched steerable multiple beam antenna system

    NASA Technical Reports Server (NTRS)

    Iwasaki, Richard S. (Inventor)

    1988-01-01

    A steerable multibeam five element cross-feed cluster antenna system is described. The feed power is divided into five branches. Each branch includes a switching network comprised of a plurality of time delay elements each individually controlled by a respective electromagnetic latching switch. Frequency independent individual two-dimensional beam steering at intermediate (IF) scanning frequencies is thereby provided wherein discrete incremental time delays are introduced by the switching networks into each branch and the signals recombined thereafter to form each beam. The electromagnetic latched switching reduces power consumption and permits higher power switching and reciprocal coincident tranmsit and receive operation. Frequency independence due to incremental time delay switching permits coincident reciprocal operation and steering for transmit-receive signal paths carrying different transmit-receive frequencies. Diagonal quarter wave plates in the waveguides alter polarization from the circular to orthogonal linear to provide transmitter-receiver isolation.

  4. Hierarchical random cellular neural networks for system-level brain-like signal processing.

    PubMed

    Kozma, Robert; Puljic, Marko

    2013-09-01

    Sensory information processing and cognition in brains are modeled using dynamic systems theory. The brain's dynamic state is described by a trajectory evolving in a high-dimensional state space. We introduce a hierarchy of random cellular automata as the mathematical tools to describe the spatio-temporal dynamics of the cortex. The corresponding brain model is called neuropercolation which has distinct advantages compared to traditional models using differential equations, especially in describing spatio-temporal discontinuities in the form of phase transitions. Phase transitions demarcate singularities in brain operations at critical conditions, which are viewed as hallmarks of higher cognition and awareness experience. The introduced Monte-Carlo simulations obtained by parallel computing point to the importance of computer implementations using very large-scale integration (VLSI) and analog platforms.

  5. Hierarchical Gene Selection and Genetic Fuzzy System for Cancer Microarray Data Classification

    PubMed Central

    Nguyen, Thanh; Khosravi, Abbas; Creighton, Douglas; Nahavandi, Saeid

    2015-01-01

    This paper introduces a novel approach to gene selection based on a substantial modification of analytic hierarchy process (AHP). The modified AHP systematically integrates outcomes of individual filter methods to select the most informative genes for microarray classification. Five individual ranking methods including t-test, entropy, receiver operating characteristic (ROC) curve, Wilcoxon and signal to noise ratio are employed to rank genes. These ranked genes are then considered as inputs for the modified AHP. Additionally, a method that uses fuzzy standard additive model (FSAM) for cancer classification based on genes selected by AHP is also proposed in this paper. Traditional FSAM learning is a hybrid process comprising unsupervised structure learning and supervised parameter tuning. Genetic algorithm (GA) is incorporated in-between unsupervised and supervised training to optimize the number of fuzzy rules. The integration of GA enables FSAM to deal with the high-dimensional-low-sample nature of microarray data and thus enhance the efficiency of the classification. Experiments are carried out on numerous microarray datasets. Results demonstrate the performance dominance of the AHP-based gene selection against the single ranking methods. Furthermore, the combination of AHP-FSAM shows a great accuracy in microarray data classification compared to various competing classifiers. The proposed approach therefore is useful for medical practitioners and clinicians as a decision support system that can be implemented in the real medical practice. PMID:25823003

  6. Incorporation of a hierarchical grid component structure into GRIDGEN

    NASA Technical Reports Server (NTRS)

    Steinbrenner, John P.; Chawner, John R.

    1993-01-01

    The underlying framework of the GRIDGEN multiple block grid generation system has been refined so that grid components are now stored within a hierarchical data structure. This restructuring has enhanced the usability of the software by allowing grids to be generated on a more intuitive level. This new framework also provides a means by which the multiple block system can be edited at most any level in the grid generation process. Editing tools are currently being added to GRIDGEN so that a change to the grid can be propagated backward and forward in the data hierarchy. The new data structure, the editing tools, and other recent GRIDGEN improvements are described in this paper.

  7. Architecture of Kepler's Multiple Planet Systems

    NASA Astrophysics Data System (ADS)

    Lissauer, Jack

    We propose to determine the typical characteristics of planetary systems within 1 AU of stars. We will address basic questions including: How many planets are typical? What are their orbital spacings? How do these relate to planet sizes, relative inclinations, and stellar type? These questions probe the signatures of planet formation that are recorded in the catalogs of Kepler planet candidates. We propose to update the findings Lissauer et al. (2011, ApJS 197, 8), which used the first four months of Kepler observations, and Fabrycky et al. (2014, ApJ 790, 146) to encompass the additional planet candidates that have and will be cataloged by the Kepler project. The current catalog (Coughlin et al. (2015, arXiv 1512.06149) includes four times as many planet candidates as were known in 2011, almost twice as many as the catalog used by Fabrycky et al., as well as vastly improved measures of planetary radii and stellar properties. The improved catalogs will allow us to minimize detection biases andperform independent analyses of subsets of the data to compare distributions of planet periodratios, transit durations and planet radii to determine how these vary with orbital distance orincident fluxes. Analyses of the early Kepler data also identified an excess of planets just wide of resonance and a deficit just narrow of resonance. We propose to discriminate between tidal and dynamical models for this phenomenon with improved distributions of period ratios, sorted by planet size and orbit period, since tidal effects decline rapidly with distance from the star.

  8. Stability and Evolution of Multiple Planet and Satellite Systems

    NASA Astrophysics Data System (ADS)

    Quillen, Alice

    Numerous multiple planet systems have recently been discovered with the Kepler Mission, suggesting that multiple planet systems are common. Multiple- body nearly coplanar satellite systems are also found in the Solar system. Multiple planet and satellite systems exhibit rich dynamics as they are affected by three-body and secular resonances affecting short timescale behavior and long timescale stability. Interactions with debris disks and planetesimal belts and tidal interactions can both reduce and induce instability. Using both numerical and analytical studies, we propose to develop a broadly applicable framework to estimate diffusion rates and stability regimes both in resonant and non- resonant configurations. Understanding of resonant dynamics is needed to understand each of these systems and a broader general theory would cover scenarios and mechanisms that are relevant for all of them. Architectures and dynamical mechanisms will be used to test scenarios for formation and evolution of multiple body systems and constrain poorly known quantities such as masses, eccentricities, inclinations, radii, and the existence of undetected bodies.

  9. HIP 3678: a hierarchical triple stellar system in the centre of the planetary nebula NGC 246

    NASA Astrophysics Data System (ADS)

    Adam, C.; Mugrauer, M.

    2014-11-01

    We report the detection of a new low-mass stellar companion to the white dwarf HIP 3678 A, the central star of the planetary nebula NGC 246. The newly found companion is located about 1 arcsec (at projected separation of about 500 au) north-east of HIP 3678 A, and shares a common proper motion with the white dwarf and its known comoving companion HIP 3678 B. The hypothesis that the newly detected companion is a non-moving background object can be rejected on a significance level of more than 8σ, by combining astrometric measurements from the literature with follow-up astrometry, obtained with Wide Field Planetary Camera 2/Hubble Space Telescope and NACO/Very Large Telescope. From our deep NACO imaging data, we can rule out additional stellar companions of the white dwarf with projected separations between 130 up to 5500 au. In the deepest high-contrast NACO observation, we achieve a detection limit in the Ks band of about 20 mag, which allows the detection of brown dwarf companions with masses down to 36 Mjup at an assumed age of the system of 260 Myr. To approximate the masses of the companions HIP 3678 B and C, we use the evolutionary Baraffe et al. models and obtain about 0.85 M⊙ for HIP 3678 B and about 0.1 M⊙ for HIP 3678 C. According to the derived absolute photometry, HIP 3678 B should be a early to mid-K dwarf (K2-K5), while HIP 3678 C should be a mid M dwarf with a spectral type in the range between M5 and M6.

  10. WASP-22 b: A TRANSITING 'HOT JUPITER' PLANET IN A HIERARCHICAL TRIPLE SYSTEM

    SciTech Connect

    Maxted, P. F. L.; Anderson, D. R.; Hellier, C.; Smalley, B.; Wilson, D. M.; Bentley, S. J.; Cegla, H.; Gillon, M.; Queloz, D.; Triaud, A. H. M. J.; Mayor, M.; Pepe, F.; West, R. G.; Collier Cameron, A.; Enoch, B.; Hebb, L.; Horne, K.; Parley, N.; Irwin, J.; Lister, T. A.

    2010-12-15

    We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T{sub eff} = 6000 {+-} 100 K, [Fe/H] = -0.05 {+-} 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M{sub p} = 0.56 {+-} 0.02M{sub Jup} and a radius R{sub p} = 1.12 {+-} 0.04R{sub Jup}. In addition, there is a linear trend of 40 m s{sup -1} yr{sup -1} in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet.

  11. Large eccentricity, low mutual inclination: the three-dimensional architecture of a hierarchical system of giant planets

    SciTech Connect

    Dawson, Rebekah I.; Clubb, Kelsey I.; Johnson, John Asher; Murray-Clay, Ruth A.; Fabrycky, Daniel C.; Foreman-Mackey, Daniel; Buchhave, Lars A.; Cargile, Phillip A.; Fulton, Benjamin J.; Howard, Andrew W.; Hebb, Leslie; Huber, Daniel; Shporer, Avi; Valenti, Jeff A.

    2014-08-20

    We establish the three-dimensional architecture of the Kepler-419 (previously KOI-1474) system to be eccentric yet with a low mutual inclination. Kepler-419b is a warm Jupiter at semi-major axis a=0.370{sub −0.006}{sup +0.007} AU with a large eccentricity (e = 0.85{sub −0.07}{sup +0.08}) measured via the 'photoeccentric effect'. It exhibits transit timing variations (TTVs) induced by the non-transiting Kepler-419c, which we uniquely constrain to be a moderately eccentric (e = 0.184 ± 0.002), hierarchically separated (a = 1.68 ± 0.03 AU) giant planet (7.3 ± 0.4 M {sub Jup}). We combine 16 quarters of Kepler photometry, radial-velocity (RV) measurements from the HIgh Resolution Echelle Spectrometer on Keck, and improved stellar parameters that we derive from spectroscopy and asteroseismology. From the RVs, we measure the mass of the inner planet to be 2.5 ± 0.3 M {sub Jup} and confirm its photometrically measured eccentricity, refining the value to e = 0.83 ± 0.01. The RV acceleration is consistent with the properties of the outer planet derived from TTVs. We find that despite their sizable eccentricities, the planets are coplanar to within 9{sub −6}{sup +8} degrees, and therefore the inner planet's large eccentricity and close-in orbit are unlikely to be the result of Kozai migration. Moreover, even over many secular cycles, the inner planet's periapse is most likely never small enough for tidal circularization. Finally, we present and measure a transit time and impact parameter from four simultaneous ground-based light curves from 1 m class telescopes, demonstrating the feasibility of ground-based follow-up of Kepler giant planets exhibiting large TTVs.

  12. Hebbian learning of hand-centred representations in a hierarchical neural network model of the primate visual system

    PubMed Central

    Born, Jannis; Stringer, Simon M.

    2017-01-01

    A subset of neurons in the posterior parietal and premotor areas of the primate brain respond to the locations of visual targets in a hand-centred frame of reference. Such hand-centred visual representations are thought to play an important role in visually-guided reaching to target locations in space. In this paper we show how a biologically plausible, Hebbian learning mechanism may account for the development of localized hand-centred representations in a hierarchical neural network model of the primate visual system, VisNet. The hand-centered neurons developed in the model use an invariance learning mechanism known as continuous transformation (CT) learning. In contrast to previous theoretical proposals for the development of hand-centered visual representations, CT learning does not need a memory trace of recent neuronal activity to be incorporated in the synaptic learning rule. Instead, CT learning relies solely on a Hebbian learning rule, which is able to exploit the spatial overlap that naturally occurs between successive images of a hand-object configuration as it is shifted across different retinal locations due to saccades. Our simulations show how individual neurons in the network model can learn to respond selectively to target objects in particular locations with respect to the hand, irrespective of where the hand-object configuration occurs on the retina. The response properties of these hand-centred neurons further generalise to localised receptive fields in the hand-centred space when tested on novel hand-object configurations that have not been explored during training. Indeed, even when the network is trained with target objects presented across a near continuum of locations around the hand during training, the model continues to develop hand-centred neurons with localised receptive fields in hand-centred space. With the help of principal component analysis, we provide the first theoretical framework that explains the behavior of Hebbian learning

  13. Hebbian learning of hand-centred representations in a hierarchical neural network model of the primate visual system.

    PubMed

    Born, Jannis; Galeazzi, Juan M; Stringer, Simon M

    2017-01-01

    A subset of neurons in the posterior parietal and premotor areas of the primate brain respond to the locations of visual targets in a hand-centred frame of reference. Such hand-centred visual representations are thought to play an important role in visually-guided reaching to target locations in space. In this paper we show how a biologically plausible, Hebbian learning mechanism may account for the development of localized hand-centred representations in a hierarchical neural network model of the primate visual system, VisNet. The hand-centered neurons developed in the model use an invariance learning mechanism known as continuous transformation (CT) learning. In contrast to previous theoretical proposals for the development of hand-centered visual representations, CT learning does not need a memory trace of recent neuronal activity to be incorporated in the synaptic learning rule. Instead, CT learning relies solely on a Hebbian learning rule, which is able to exploit the spatial overlap that naturally occurs between successive images of a hand-object configuration as it is shifted across different retinal locations due to saccades. Our simulations show how individual neurons in the network model can learn to respond selectively to target objects in particular locations with respect to the hand, irrespective of where the hand-object configuration occurs on the retina. The response properties of these hand-centred neurons further generalise to localised receptive fields in the hand-centred space when tested on novel hand-object configurations that have not been explored during training. Indeed, even when the network is trained with target objects presented across a near continuum of locations around the hand during training, the model continues to develop hand-centred neurons with localised receptive fields in hand-centred space. With the help of principal component analysis, we provide the first theoretical framework that explains the behavior of Hebbian learning

  14. Hierarchically nanostructured materials for sustainable environmental applications

    PubMed Central

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-01-01

    This review presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions, and multiple functionalities toward water remediation, biosensing, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing, and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology. PMID:24790946

  15. Hierarchically Nanostructured Materials for Sustainable Environmental Applications

    NASA Astrophysics Data System (ADS)

    Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian

    2013-11-01

    This article presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions and multiple functionalities towards water remediation, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

  16. Systemic inflammation and multiple organ injury in traumatic hemorrhagic shock.

    PubMed

    Liu, Huaizheng; Xiao, Xuefei; Sun, Chuanzheng; Sun, Dao; Li, Yayong; Yang, Mingshi

    2015-06-01

    Traumatic hemorrhagic shock (HS) is a severe outcome of traumatic injury that accounts for numerous traumatic deaths. In the process of traumatic HS, both hemorrhage and trauma can trigger a complex cascade of posttraumatic events that are related to inflammatory and immune responses, which may lead to multiple organ injury or even death. From a mechanistic perspective, systemic inflammation and organ injury are involved coagulation, the complement system, impaired microcirculation and inflammatory signaling pathways. In this review, we discuss the systemic inflammation and multiple organ injury in post-traumatic HS.

  17. Using Multiple Unmanned Systems for a Site Security Task

    SciTech Connect

    Matthew O. Anderson; Curtis W. Nielsen; Mark D. McKay; Derek C. Wadsworth; Ryan C. Hruska; John A. Koudelka

    2009-04-01

    Unmanned systems are often used to augment the ability of humans to perform challenging tasks. While the value of individual unmanned vehicles have been proven for a variety of tasks, it is less understood how multiple unmanned systems should be used together to accomplish larger missions such as site security. The purpose of this paper is to discuss efforts by researchers at the Idaho National Laboratory (INL) to explore the utility and practicality of operating multiple unmanned systems for a site security mission. This paper reviews the technology developed for a multi-agent mission and summarizes the lessons-learned from a technology demonstration.

  18. Viscous boundary value problems for symmetric systems with variable multiplicities

    NASA Astrophysics Data System (ADS)

    Gues, Olivier; Métivier, Guy; Williams, Mark; Zumbrun, Kevin

    Extending investigations of Métivier and Zumbrun in the hyperbolic case, we treat stability of viscous shock and boundary layers for viscous perturbations of multidimensional hyperbolic systems with characteristics of variable multiplicity, specifically the construction of symmetrizers in the low-frequency regime where variable multiplicity plays a role. At the same time, we extend the boundary-layer theory to "real" or partially parabolic viscosities, Neumann or mixed-type parabolic boundary conditions, and systems with nonconservative form, in addition proving a more fundamental version of the Zumbrun-Serre-Rousset theorem, valid for variable multiplicities, characterizing the limiting hyperbolic system and boundary conditions as a nonsingular limit of a reduced viscous system. The new effects of viscosity are seen to be surprisingly subtle; in particular, viscous coupling of crossing hyperbolic modes may induce a destabilizing effect. We illustrate the theory with applications to magnetohydrodynamics.

  19. MOOSES: Multiple Option Observation System for Experimental Studies.

    ERIC Educational Resources Information Center

    Tapp, Jon; Wehby, Joseph

    The Multiple Option Observation System for Experimental Studies (MOOSES) is a flexible data collection and analysis package for applied behavioral research that addresses the needs of researchers interested in live coding of observational data. MOOSES allows the researcher to design a coding system for a particular research question. General types…

  20. MULTIPLE PROJECTIONS SYSTEM (MPS) - USER'S MANUAL VERSION 1.0

    EPA Science Inventory

    The report is a user's manual for version 1.0 of the Multiple Projections Systems (MPS), a computer system that can perform "what if" scenario analysis and report the final results (i.e., Rate of Further Progress - ROP - inventories) to EPA (i.e., the Aerometric Information Retri...