WorldWideScience

Sample records for public domain simulation

  1. A high-order public domain code for direct numerical simulations of turbulent combustion

    CERN Document Server

    Babkovskaia, N; Brandenburg, A

    2010-01-01

    A high-order scheme for direct numerical simulations of turbulent combustion is discussed. Its implementation in the massively parallel and publicly available Pencil Code is validated with the focus on hydrogen combustion. Ignition delay times (0D) and laminar flame velocities (1D) are calculated and compared with results from the commercially available Chemkin code. The scheme is verified to be fifth order in space. Upon doubling the resolution, a 32-fold increase in the accuracy of the flame front is demonstrated. Finally, also turbulent and spherical flame front velocities are calculated and the implementation of the non-reflecting so-called Navier-Stokes Characteristic Boundary Condition is validated in all three directions.

  2. PUBLIC DOMAIN PROTECTION. USES AND REUSES OF PUBLIC DOMAIN WORKS

    OpenAIRE

    Monica Adriana LUPAȘCU

    2015-01-01

    This study tries to highlight the necessity of an awareness of the right of access to the public domain, particularly using the example of works whose protection period has expired, as well as the ones which the law considers to be excluded from protection. Such works are used not only by large libraries from around the world, but also by rights holders, via different means of use, including incorporations into original works or adaptations. However, the reuse that follows these uses often on...

  3. Cultural Heritage and the Public Domain

    Directory of Open Access Journals (Sweden)

    Bas Savenije

    2012-09-01

    by providing their resources on the Internet” (Berlin Declaration 2003. Therefore, in the spirit of the Berlin Declaration, the ARL encourages its members’ libraries to grant all non-commercial users “a free, irrevocable, worldwide, right of access to, and a license to copy, use, distribute, transmit and display the work publicly and to make and distribute derivative works, in any digital medium for any responsible purpose, subject to proper attribution of authorship”. And: “If fees are to be assessed for the use of digitised public domain works, those fees should only apply to commercial uses” (ARL Principles July 2010. In our view, cultural heritage institutions should make public domain material digitised with public funding as widely available as possible for access and reuse. The public sector has the primary responsibility to fund digitisation. The involvement of private partners, however, is encouraged by ARL as well as the Comité des Sages. Private funding for digitisation is a complement to the necessary public investment, especially in times of economic crisis, but should not be seen as a substitute for public funding. As we can see from these reports there are a number of arguments in favour of digitisation and also of providing maximum accessibility to the digitised cultural heritage. In this paper we will investigate the legal aspects of digitisation of cultural heritage, especially public domain material. On the basis of these we will make an inventory of policy considerations regarding reuse. Furthermore, we will describe the conclusions the National Library of the Netherlands (hereafter: KB has formulated and the arguments that support these. In this context we will review public-private partnerships and also the policy of the KB. We will conclude with recommendations for cultural heritage institutions concerning a reuse policy for digitised public domain material.

  4. Agents unleashed a public domain look at agent technology

    CERN Document Server

    Wayner, Peter

    1995-01-01

    Agents Unleashed: A Public Domain Look at Agent Technology covers details of building a secure agent realm. The book discusses the technology for creating seamlessly integrated networks that allow programs to move from machine to machine without leaving a trail of havoc; as well as the technical details of how an agent will move through the network, prove its identity, and execute its code without endangering the host. The text also describes the organization of the host's work processing an agent; error messages, bad agent expulsion, and errors in XLISP-agents; and the simulators of errors, f

  5. LHC RF System Time-Domain Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Mastorides, T.; Rivetta, C.; /SLAC

    2010-09-14

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  6. Preserving the positive functions of the public domain in science

    Directory of Open Access Journals (Sweden)

    Pamela Samuelson

    2003-11-01

    Full Text Available Science has advanced in part because data and scientific methodologies have traditionally not been subject to intellectual property protection. In recent years, intellectual property has played a greater role in scientific work. While intellectual property rights may have a positive role to play in some fields of science, so does the public domain. This paper will discuss some of the positive functions of the public domain and ways in which certain legal developments may negatively impact the public domain. It suggests some steps that scientists can take to preserve the positive functions of the public domain for science.

  7. Teaching Public Speaking with Simulations.

    Science.gov (United States)

    Kell, Carl L.; Winn, Larry James

    In public-speaking courses, the use of games--a specific type of simulation--can help to overcome three of the most basic problems faced by the teacher: the gap between the study of theory and the application of that theory, the limited experience gained by students confined to speaking situations within classroom walls, and student stage fright.…

  8. The Definition, Dimensions, and Domain of Public Relations.

    Science.gov (United States)

    Hutton, James G.

    1999-01-01

    Discusses how the field of public relations has left itself vulnerable to other fields that are making inroads into public relations' traditional domain, and to critics who are filling in their own definitions of public relations. Proposes a definition and a three-dimensional framework to compare competing philosophies of public relations and to…

  9. Public Infrastructure for Monte Carlo Simulation: publicMC@BATAN

    CERN Document Server

    Waskita, A A; Akbar, Z; Handoko, L T; 10.1063/1.3462759

    2010-01-01

    The first cluster-based public computing for Monte Carlo simulation in Indonesia is introduced. The system has been developed to enable public to perform Monte Carlo simulation on a parallel computer through an integrated and user friendly dynamic web interface. The beta version, so called publicMC@BATAN, has been released and implemented for internal users at the National Nuclear Energy Agency (BATAN). In this paper the concept and architecture of publicMC@BATAN are presented.

  10. Development and Initial Validation of Public Domain Basic Interest Markers

    Science.gov (United States)

    Liao, Hsin-Ya; Armstrong, Patrick Ian; Rounds, James

    2008-01-01

    Goldberg (Goldberg, L. R. (1999). "A broad-bandwidth, public-domain, personality inventory measuring the lower-level facets of several five-factor models." In: I. Mervielde, I. Deary, F. De Fruyt, & F. Ostendorf (Eds.), "Personality psychology in Europe" (Vol. 7, pp. 7-28). Tilburg, The Netherlands: Tilburg University Press) has argued that the…

  11. Copyright and the Value of the Public Domain

    OpenAIRE

    Erickson, Kristofer; Heald, Paul; Homberg, Fabian; Kretschmer, Martin; Mendis, Dinusha

    2015-01-01

    This research report documents the results of a year-long knowledge exchange initiative undertaken between the Intellectual Property Office, researchers at the University of Glasgow CREATe Centre, and more than two dozen UK businesses and innovators, to explore how value is generated from the public domain. The study was supported by the Economic and Social Research Council (ESRC) and the Intellectual Property Office (IPO). The core research team consisted of Dr. Kristofer Erickson (Lord Kelv...

  12. Agent-based Simulation of the Maritime Domain

    Directory of Open Access Journals (Sweden)

    O. Vaněk

    2010-01-01

    Full Text Available In this paper, a multi-agent based simulation platform is introduced that focuses on legitimate and illegitimate aspects of maritime traffic, mainly on intercontinental transport through piracy afflicted areas. The extensible architecture presented here comprises several modules controlling the simulation and the life-cycle of the agents, analyzing the simulation output and visualizing the entire simulated domain. The simulation control module is initialized by various configuration scenarios to simulate various real-world situations, such as a pirate ambush, coordinated transit through a transport corridor, or coastal fishing and local traffic. The environmental model provides a rich set of inputs for agents that use the geo-spatial data and the vessel operational characteristics for their reasoning. The agent behavior model based on finite state machines together with planning algorithms allows complex expression of agent behavior, so the resulting simulation output can serve as a substitution for real world data from the maritime domain.

  13. Computational simulation of wave propagation problems in infinite domains

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper deals with the computational simulation of both scalar wave and vector wave propagation problems in infinite domains. Due to its advantages in simulating complicated geometry and complex material properties, the finite element method is used to simulate the near field of a wave propagation problem involving an infinite domain. To avoid wave reflection and refraction at the common boundary between the near field and the far field of an infinite domain, we have to use some special treatments to this boundary. For a wave radiation problem, a wave absorbing boundary can be applied to the common boundary between the near field and the far field of an infinite domain, while for a wave scattering problem, the dynamic infinite element can be used to propagate the incident wave from the near field to the far field of the infinite domain. For the sake of illustrating how these two different approaches are used to simulate the effect of the far field, a mathematical expression for a wave absorbing boundary of high-order accuracy is derived from a two-dimensional scalar wave radiation problem in an infinite domain, while the detailed mathematical formulation of the dynamic infinite element is derived from a two-dimensional vector wave scattering problem in an infinite domain. Finally, the coupled method of finite elements and dynamic infinite elements is used to investigate the effects of topographical conditions on the free field motion along the surface of a canyon.

  14. Modeling human response errors in synthetic flight simulator domain

    Science.gov (United States)

    Ntuen, Celestine A.

    1992-01-01

    This paper presents a control theoretic approach to modeling human response errors (HRE) in the flight simulation domain. The human pilot is modeled as a supervisor of a highly automated system. The synthesis uses the theory of optimal control pilot modeling for integrating the pilot's observation error and the error due to the simulation model (experimental error). Methods for solving the HRE problem are suggested. Experimental verification of the models will be tested in a flight quality handling simulation.

  15. Time Domain Partitioning of Electricity Production Cost Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Barrows, C.; Hummon, M.; Jones, W.; Hale, E.

    2014-01-01

    Production cost models are often used for planning by simulating power system operations over long time horizons. The simulation of a day-ahead energy market can take several weeks to compute. Tractability improvements are often made through model simplifications, such as: reductions in transmission modeling detail, relaxation of commitment variable integrality, reductions in cost modeling detail, etc. One common simplification is to partition the simulation horizon so that weekly or monthly horizons can be simulated in parallel. However, horizon partitions are often executed with overlap periods of arbitrary and sometimes zero length. We calculate the time domain persistence of historical unit commitment decisions to inform time domain partitioning of production cost models. The results are implemented using PLEXOS production cost modeling software in an HPC environment to improve the computation time of simulations while maintaining solution integrity.

  16. Cost efficient CFD simulations: Proper selection of domain partitioning strategies

    Science.gov (United States)

    Haddadi, Bahram; Jordan, Christian; Harasek, Michael

    2017-10-01

    Computational Fluid Dynamics (CFD) is one of the most powerful simulation methods, which is used for temporally and spatially resolved solutions of fluid flow, heat transfer, mass transfer, etc. One of the challenges of Computational Fluid Dynamics is the extreme hardware demand. Nowadays super-computers (e.g. High Performance Computing, HPC) featuring multiple CPU cores are applied for solving-the simulation domain is split into partitions for each core. Some of the different methods for partitioning are investigated in this paper. As a practical example, a new open source based solver was utilized for simulating packed bed adsorption, a common separation method within the field of thermal process engineering. Adsorption can for example be applied for removal of trace gases from a gas stream or pure gases production like Hydrogen. For comparing the performance of the partitioning methods, a 60 million cell mesh for a packed bed of spherical adsorbents was created; one second of the adsorption process was simulated. Different partitioning methods available in OpenFOAM® (Scotch, Simple, and Hierarchical) have been used with different numbers of sub-domains. The effect of the different methods and number of processor cores on the simulation speedup and also energy consumption were investigated for two different hardware infrastructures (Vienna Scientific Clusters VSC 2 and VSC 3). As a general recommendation an optimum number of cells per processor core was calculated. Optimized simulation speed, lower energy consumption and consequently the cost effects are reported here.

  17. Public-domain software for root image analysis

    Directory of Open Access Journals (Sweden)

    Mirian Cristina Gomes Costa

    2014-10-01

    Full Text Available In the search for high efficiency in root studies, computational systems have been developed to analyze digital images. ImageJ and Safira are public-domain systems that may be used for image analysis of washed roots. However, differences in root properties measured using ImageJ and Safira are supposed. This study compared values of root length and surface area obtained with public-domain systems with values obtained by a reference method. Root samples were collected in a banana plantation in an area of a shallower Typic Carbonatic Haplic Cambisol (CXk, and an area of a deeper Typic Haplic Ta Eutrophic Cambisol (CXve, at six depths in five replications. Root images were digitized and the systems ImageJ and Safira used to determine root length and surface area. The line-intersect method modified by Tennant was used as reference; values of root length and surface area measured with the different systems were analyzed by Pearson's correlation coefficient and compared by the confidence interval and t-test. Both systems ImageJ and Safira had positive correlation coefficients with the reference method for root length and surface area data in CXk and CXve. The correlation coefficient ranged from 0.54 to 0.80, with lowest value observed for ImageJ in the measurement of surface area of roots sampled in CXve. The IC (95 % revealed that root length measurements with Safira did not differ from that with the reference method in CXk (-77.3 to 244.0 mm. Regarding surface area measurements, Safira did not differ from the reference method for samples collected in CXk (-530.6 to 565.8 mm² as well as in CXve (-4231 to 612.1 mm². However, measurements with ImageJ were different from those obtained by the reference method, underestimating length and surface area in samples collected in CXk and CXve. Both ImageJ and Safira allow an identification of increases or decreases in root length and surface area. However, Safira results for root length and surface area are

  18. Time domain simulations of preliminary breakdown pulses in natural lightning

    CERN Document Server

    Carlson, B E; Bitzer, P; Christian, H

    2016-01-01

    Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mecha...

  19. Assessment of current cybersecurity practices in the public domain : cyber indications and warnings domain.

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Keliiaa, Curtis M.

    2010-09-01

    This report assesses current public domain cyber security practices with respect to cyber indications and warnings. It describes cybersecurity industry and government activities, including cybersecurity tools, methods, practices, and international and government-wide initiatives known to be impacting current practice. Of particular note are the U.S. Government's Trusted Internet Connection (TIC) and 'Einstein' programs, which are serving to consolidate the Government's internet access points and to provide some capability to monitor and mitigate cyber attacks. Next, this report catalogs activities undertaken by various industry and government entities. In addition, it assesses the benchmarks of HPC capability and other HPC attributes that may lend themselves to assist in the solution of this problem. This report draws few conclusions, as it is intended to assess current practice in preparation for future work, however, no explicit references to HPC usage for the purpose of analyzing cyber infrastructure in near-real-time were found in the current practice. This report and a related SAND2010-4766 National Cyber Defense High Performance Computing and Analysis: Concepts, Planning and Roadmap report are intended to provoke discussion throughout a broad audience about developing a cohesive HPC centric solution to wide-area cybersecurity problems.

  20. The Illustris Simulation: Public Data Release

    CERN Document Server

    Nelson, Dylan; Genel, Shy; Vogelsberger, Mark; Springel, Volker; Torrey, Paul; Rodriguez-Gomez, Vicente; Sijacki, Debora; Snyder, Gregory F; Griffen, Brendan; Marinacci, Federico; Blecha, Laura; Sales, Laura; Xu, Dandan; Hernquist, Lars

    2015-01-01

    We present the full public release of all data from the Illustris simulation project. Illustris is a suite of large volume, cosmological hydrodynamical simulations run with the moving-mesh code Arepo and including a comprehensive set of physical models critical for following the formation and evolution of galaxies across cosmic time. Each simulates a volume of (106.5 Mpc)^3 and self-consistently evolves five different types of resolution elements from a starting redshift of z=127 to the present day, z=0. These components are: dark matter particles, gas cells, passive gas tracers, stars and stellar wind particles, and supermassive black holes. This data release includes the snapshots at all 136 available redshifts, halo and subhalo catalogs at each snapshot, and two distinct merger trees. Six primary realizations of the Illustris volume are released, including the flagship Illustris-1 run. These include three resolution levels with the fiducial "full" baryonic physics model, and a dark matter only analog for e...

  1. Simulating Observer in Supervisory Control- A Domain-based Method

    Directory of Open Access Journals (Sweden)

    Seyed Morteza Babamir

    2012-06-01

    Full Text Available An Observer in the supervisory control observes responses of a discrete system to events of its environment and reports an unsafe/ critical situation if the response is undesired. An undesired response from the system indicates the system response does not adhere to users’ requirements of the system. Therefore, events and conditions of the system environment and user’s requirements of the system are basic elements to observer in determining correctness of the system response. However, the noteworthy matter is that the events, conditions, and requirements should be defined based on data of problem domain because discrete data are primary ingredients of the environment in discrete systems and they are used by system users as a gauge to express their requirements playing a vital role in safety-critical systems, such as medical and avionic ones. A large quantity of methods has already been proposed to model and simulate supervisory control of discrete systems however, a systematic method relying on data of problem domain is missing. Having extracted events, conditions, and user’s requirements from data of problem domain, a Petri-Net automaton is constructed for identifying violation of user’s requirements. The net constitutes the core of the observer and it is used to identify undesired responses of the system. In the third step, run-time simulation of the observer is suggested using multithreading mechanism and Task Parallel Library (TPL technology of Microsoft. Finally, a case study of a discrete concurrent system is proposed, the method applied and simulation results are analyzed based on the system implementation on a multi-core computer.

  2. An outlook on the nature of mental creations after belonging to public domain

    Directory of Open Access Journals (Sweden)

    Pedjman Mohammadi

    2015-05-01

    Full Text Available The public domain of copyright which considers the end of protection period, attempts to cause balance among the rights of authors, society and third parties. So at the end of financial rights of author’s protection period the possibility of free utilization of these literary works will be possible. But in this situation one of the controversial difficulties is the nature of these kinds of literary works which, according to some scholars, after belonging to public domain, they will change in to the Allowable. To approve their idea, they focus on common features existing in these literary works(works relating to public domain and the Allowable. On the other hand it is believed that literary works after belonging to public domain essentially works after belonging to public domain essentially due to lacking of scarcity element are not considered property at all.

  3. The illustris simulation: Public data release

    Science.gov (United States)

    Nelson, D.; Pillepich, A.; Genel, S.; Vogelsberger, M.; Springel, V.; Torrey, P.; Rodriguez-Gomez, V.; Sijacki, D.; Snyder, G. F.; Griffen, B.; Marinacci, F.; Blecha, L.; Sales, L.; Xu, D.; Hernquist, L.

    2015-11-01

    We present the full public release of all data from the Illustris simulation project. Illustris is a suite of large volume, cosmological hydrodynamical simulations run with the moving-mesh code AREPO and including a comprehensive set of physical models critical for following the formation and evolution of galaxies across cosmic time. Each simulates a volume of (106.5 Mpc)3 and self-consistently evolves five different types of resolution elements from a starting redshift of z = 127 to the present day, z = 0. These components are: dark matter particles, gas cells, passive gas tracers, stars and stellar wind particles, and supermassive black holes. This data release includes the snapshots at all 136 available redshifts, halo and subhalo catalogs at each snapshot, and two distinct merger trees. Six primary realizations of the Illustris volume are released, including the flagship Illustris-1 run. These include three resolution levels with the fiducial "full" baryonic physics model, and a dark matter only analog for each. In addition, we provide four distinct, high time resolution, smaller volume "subboxes". The total data volume is ∼265 TB, including ∼800 full volume snapshots and ∼30,000 subbox snapshots. We describe the released data products as well as tools we have developed for their analysis. All data may be directly downloaded in its native HDF5 format. Additionally, we release a comprehensive, web-based API which allows programmatic access to search and data processing tasks. In both cases we provide example scripts and a getting-started guide in several languages: currently, IDL, Python, and Matlab. This paper addresses scientific issues relevant for the interpretation of the simulations, serves as a pointer to published and on-line documentation of the project, describes planned future additional data releases, and discusses technical aspects of the release.

  4. Time domain simulations of preliminary breakdown pulses in natural lightning

    Science.gov (United States)

    Carlson, B E; Liang, C; Bitzer, P; Christian, H

    2015-01-01

    Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism. Key Points Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations PMID:26664815

  5. Time domain simulations of preliminary breakdown pulses in natural lightning.

    Science.gov (United States)

    Carlson, B E; Liang, C; Bitzer, P; Christian, H

    2015-06-16

    Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism. Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations.

  6. Mixed-domain multi-simulator statistical device modeling and yiel-driven design

    OpenAIRE

    Bandler, J.W.; Biernacki, R.M.; S. H. Chen

    1997-01-01

    We present mixed-domain, multi-simulator approaches to device modeling and yield-driven optimization. Intelligent computational interfaces combine and enhance the features of otherwise disjoint simulators. Time-domain, frequency-domain and electromagnetic simulations are integrated for efficient statistical modeling and design with mixed-domain specifications. Our approach is demonstrated by statistical modeling of GaAs MESFETs and yield optimization using, simultaneously, SPICE device models...

  7. Mixed-domain multi-simulator statistical device modeling and yiel-driven design

    OpenAIRE

    Bandler, J.W.; Biernacki, R.M.; Chen, S H

    1997-01-01

    We present mixed-domain, multi-simulator approaches to device modeling and yield-driven optimization. Intelligent computational interfaces combine and enhance the features of otherwise disjoint simulators. Time-domain, frequency-domain and electromagnetic simulations are integrated for efficient statistical modeling and design with mixed-domain specifications. Our approach is demonstrated by statistical modeling of GaAs MESFETs and yield optimization using, simultaneously, SPICE device models...

  8. Using Crisis Simulations in Public Relations Education

    Science.gov (United States)

    Veil, Shari R.

    2010-01-01

    Objectives: Students will demonstrate research, decision making, team building, and public speaking skills, while applying issues management and crisis communication concepts in a realistic setting. Courses: Introduction to Public Relations, Public Relations Cases, Crisis Communication.

  9. Using Crisis Simulations in Public Relations Education

    Science.gov (United States)

    Veil, Shari R.

    2010-01-01

    Objectives: Students will demonstrate research, decision making, team building, and public speaking skills, while applying issues management and crisis communication concepts in a realistic setting. Courses: Introduction to Public Relations, Public Relations Cases, Crisis Communication.

  10. A fictitious domain approach for the simulation of dense suspensions

    Science.gov (United States)

    Gallier, Stany; Lemaire, Elisabeth; Lobry, Laurent; Peters, François

    2014-01-01

    Low Reynolds number concentrated suspensions do exhibit an intricate physics which can be partly unraveled by the use of numerical simulation. To this end, a Lagrange multiplier-free fictitious domain approach is described in this work. Unlike some methods recently proposed, the present approach is fully Eulerian and therefore does not need any transfer between the Eulerian background grid and some Lagrangian nodes attached to particles. Lubrication forces between particles play an important role in the suspension rheology and have been properly accounted for in the model. A robust and effective lubrication scheme is outlined which consists in transposing the classical approach used in Stokesian Dynamics to our present direct numerical simulation. This lubrication model has also been adapted to account for solid boundaries such as walls. Contact forces between particles are modeled using a classical Discrete Element Method (DEM), a widely used method in granular matter physics. Comprehensive validations are presented on various one-particle, two-particle or three-particle configurations in a linear shear flow as well as some O(103) and O(104) particle simulations.

  11. The Use and Abuse of Research in the Public Domain

    Science.gov (United States)

    Reid, Alan

    2016-01-01

    In Australia, education think tanks have become increasingly influential in policy circles through "reports" to government, and in public debate through the mainstream media. Invariably think-tanks draw on educational research to lend authority and legitimacy to their work. This is desirable if the research deepens understandings about…

  12. The international river interface cooperative: Public domain flow and morphodynamics software for education and applications

    Science.gov (United States)

    Nelson, Jonathan M.; Shimizu, Yasuyuki; Abe, Takaaki; Asahi, Kazutake; Gamou, Mineyuki; Inoue, Takuya; Iwasaki, Toshiki; Kakinuma, Takaharu; Kawamura, Satomi; Kimura, Ichiro; Kyuka, Tomoko; McDonald, Richard R.; Nabi, Mohamed; Nakatsugawa, Makoto; Simões, Francisco R.; Takebayashi, Hiroshi; Watanabe, Yasunori

    2016-07-01

    This paper describes a new, public-domain interface for modeling flow, sediment transport and morphodynamics in rivers and other geophysical flows. The interface is named after the International River Interface Cooperative (iRIC), the group that constructed the interface and many of the current solvers included in iRIC. The interface is entirely free to any user and currently houses thirteen models ranging from simple one-dimensional models through three-dimensional large-eddy simulation models. Solvers are only loosely coupled to the interface so it is straightforward to modify existing solvers or to introduce other solvers into the system. Six of the most widely-used solvers are described in detail including example calculations to serve as an aid for users choosing what approach might be most appropriate for their own applications. The example calculations range from practical computations of bed evolution in natural rivers to highly detailed predictions of the development of small-scale bedforms on an initially flat bed. The remaining solvers are also briefly described. Although the focus of most solvers is coupled flow and morphodynamics, several of the solvers are also specifically aimed at providing flood inundation predictions over large spatial domains. Potential users can download the application, solvers, manuals, and educational materials including detailed tutorials at www.-i-ric.org. The iRIC development group encourages scientists and engineers to use the tool and to consider adding their own methods to the iRIC suite of tools.

  13. The international river interface cooperative: Public domain flow and morphodynamics software for education and applications

    Science.gov (United States)

    Nelson, Jonathan M.; Shimizu, Yasuyuki; Abe, Takaaki; Asahi, Kazutake; Gamou, Mineyuki; Inoue, Takuya; Iwasaki, Toshiki; Kakinuma, Takaharu; Kawamura, Satomi; Kimura, Ichiro; Kyuka, Tomoko; McDonald, Richard R.; Nabi, Mohamed; Nakatsugawa, Makoto; Simoes, Francisco J.; Takebayashi, Hiroshi; Watanabe, Yasunori

    2016-01-01

    This paper describes a new, public-domain interface for modeling flow, sediment transport and morphodynamics in rivers and other geophysical flows. The interface is named after the International River Interface Cooperative (iRIC), the group that constructed the interface and many of the current solvers included in iRIC. The interface is entirely free to any user and currently houses thirteen models ranging from simple one-dimensional models through three-dimensional large-eddy simulation models. Solvers are only loosely coupled to the interface so it is straightforward to modify existing solvers or to introduce other solvers into the system. Six of the most widely-used solvers are described in detail including example calculations to serve as an aid for users choosing what approach might be most appropriate for their own applications. The example calculations range from practical computations of bed evolution in natural rivers to highly detailed predictions of the development of small-scale bedforms on an initially flat bed. The remaining solvers are also briefly described. Although the focus of most solvers is coupled flow and morphodynamics, several of the solvers are also specifically aimed at providing flood inundation predictions over large spatial domains. Potential users can download the application, solvers, manuals, and educational materials including detailed tutorials at www.-i-ric.org. The iRIC development group encourages scientists and engineers to use the tool and to consider adding their own methods to the iRIC suite of tools.

  14. Suburban development – a search for public domains in Danish suburban neighbourhoods

    DEFF Research Database (Denmark)

    Melgaard, Bente; Bech-Danielsen, Claus

    , potentials for bridge-building across the enclaves of the suburb are looked for through a combined architectural-anthropological mapping of public spaces in a specific suburb in Denmark, the analyses being carried out in the light of Hajer & Reijndorp’s definition of public domains and the term exchange....... The results so far show that suburban spaces with a potential for creating bridge-building across the segregated enclaves do exist but that, among other things, focus on spatial design is needed before actual public domains creating the basis for exchange are achieved....

  15. Materialities of Law: Celebrity Production and the Public Domain

    Directory of Open Access Journals (Sweden)

    Esther Milne

    2009-12-01

    Full Text Available Celebrity production and consumption are powerful socio-economic forces. The celebrity functions as a significant economic resource for the commercial sector and plays a fundamental symbolic role within culture by providing a shared ‘vocabulary’ through which to understand contemporary social relations. A pivotal element of this allure is the process by which the celebrity figure is able to forge an intimate link with its audience, often producing public expressions of profound compassion, respect or revulsion. This process, however, is complicated by emerging participatory media forms whose impact is experienced as new conditions of possibility for celebrity production and consumption. As Marshall argues, video mash-ups of celebrity interviews, such as those of Christian Bale or Tom Cruise, are dramatically changing the relation between celebrity and audience (Marshall, 2006: 640. Meanings produced by these audience remixes challenge the extent to which a celebrity might control her image. So is the celebrity personality, therefore, a public or private commodity? Who owns the celebrity image within remix culture? Although the celebrity figure has been thoroughly researched in relation to its patterns of consumption; semiotic power; and industry construction; less attention has been focused on the forms of celebrity governance enabled by legislative and case law settings. How might the law deal with the significant economic and cultural power exercised within celebrity culture?

  16. Ethics Simulations as Preparation for Public Discourse

    Science.gov (United States)

    Hamilton, James P.; Mueller, Alfred G.

    2010-01-01

    Courses: Fundamentals of public speaking, basic hybrid course, introduction to communication, introduction to journalism, introduction to advertising, and any other course that includes components of communication ethics. Objective: Students will understand the fundamental elements of communication ethics.

  17. Ethics Simulations as Preparation for Public Discourse

    Science.gov (United States)

    Hamilton, James P.; Mueller, Alfred G.

    2010-01-01

    Courses: Fundamentals of public speaking, basic hybrid course, introduction to communication, introduction to journalism, introduction to advertising, and any other course that includes components of communication ethics. Objective: Students will understand the fundamental elements of communication ethics.

  18. Simulation-Based Learning Environments to Teach Complexity: The Missing Link in Teaching Sustainable Public Management

    Directory of Open Access Journals (Sweden)

    Michael Deegan

    2014-05-01

    Full Text Available While public-sector management problems are steeped in positivistic and socially constructed complexity, public management education in the management of complexity lags behind that of business schools, particularly in the application of simulation-based learning. This paper describes a Simulation-Based Learning Environment for public management education that includes a coupled case study and System Dynamics simulation surrounding flood protection, a domain where stewardship decisions regarding public infrastructure and investment have direct and indirect effects on businesses and the public. The Pointe Claire case and CoastalProtectSIM simulation provide a platform for policy experimentation under conditions of exogenous uncertainty (weather and climate change as well as endogenous effects generated by structure. We discuss the model in some detail, and present teaching materials developed to date to support the use of our work in public administration curricula. Our experience with this case demonstrates the potential of this approach to motivate sustainable learning about complexity in public management settings and enhance learners’ competency to deal with complex dynamic problems.

  19. Simulating the symmetron: domain walls and symmetry-restoring impurities

    CERN Document Server

    Pearson, Jonathan A

    2014-01-01

    In this paper we study the dynamics of relativistic domain walls in the presence of static symmetry-restoring impurities. The field theory is precisely the same as what is known to cosmologists as the "symmetron model", whereby the usual $\\mathbb{Z}_2$ symmetry breaking potential is appended with a space-varying mass-term (the space-variation is set by the profile of the impurity, which we take to be a "tanh"-function). After presenting the outcomes of a suite of different numerical experiments we have three main results: (1) domain walls pin to impurities, (2) domain wall necklaces can be energetically preferred configurations, and (3) impurities significantly modifies the usual ${N}_{\\rm dw}\\propto t^{-1}$ scaling law for random networks of domain walls.

  20. Hybrid simulation of whistler excitation by electron beams in two-dimensional non-periodic domains

    Energy Technology Data Exchange (ETDEWEB)

    Woodroffe, J.R., E-mail: woodrofj@erau.edu; Streltsov, A.V., E-mail: streltsa@erau.edu

    2014-11-01

    We present a two-dimensional hybrid fluid-PIC scheme for the simulation of whistler wave excitation by relativistic electron beams. This scheme includes a number of features which are novel to simulations of this type, including non-periodic boundary conditions and fresh particle injection. Results from our model suggest that non-periodicity of the simulation domain results in the development of fundamentally different wave characteristics than are observed in periodic domains.

  1. Modeling, Simulation and Analysis of Public Key Infrastructure

    Science.gov (United States)

    Liu, Yuan-Kwei; Tuey, Richard; Ma, Paul (Technical Monitor)

    1998-01-01

    Security is an essential part of network communication. The advances in cryptography have provided solutions to many of the network security requirements. Public Key Infrastructure (PKI) is the foundation of the cryptography applications. The main objective of this research is to design a model to simulate a reliable, scalable, manageable, and high-performance public key infrastructure. We build a model to simulate the NASA public key infrastructure by using SimProcess and MatLab Software. The simulation is from top level all the way down to the computation needed for encryption, decryption, digital signature, and secure web server. The application of secure web server could be utilized in wireless communications. The results of the simulation are analyzed and confirmed by using queueing theory.

  2. Time domain simulation and modeling of power electronic circuits. Development of a simulation tool

    Energy Technology Data Exchange (ETDEWEB)

    Mo, O.

    1993-08-01

    This thesis presents the results of a study on the topic: Time domain modeling and simulation of power electronic circuits. The objectives of the presented work have been to improve and expand the simulation program KREAN. This also included search for, development and implementation of models suited for analysis of power electronic circuits. The main contribution of the work is the improved KREAN program itself and the models created for the program. Further, the work has led to this thesis which is a documentation of the applied methods. The thesis shows how to create a power electronic simulation tool and how to meet the special problems encountered in power electronic circuits. Among the major improvements of KREAN are: Better methods for solution of nonlinear algebraic equations. Major modifications have been implemented in the modified Newton iteration method. The old method suffered from insufficient control of the iteration error. Improved efficiency, accuracy and robustness of the breakpoint detection methods (breakpoints are time instants of discontinuous behavior in models). A new linear circuit now replaces the nonlinear modules at each stage in the iteration. The old one could give serious errors in the results and was not applicable after introduction of voltage response terminals. Several new models have been implemented as KREAN modules. Together with the old basic ones, they form a powerful set for simulation of power electronics. The thesis describes the applied methods, the implemented models and also presents results from study of the accuracy and efficiency of the program. The applied methods in the program are stated to be good enough for most simulation purposes. 100 refs., 93 figs., 14 tabs.

  3. Wideband Radar Echo Frequency-domain Simulation and Analysis for High Speed Moving Targets

    Directory of Open Access Journals (Sweden)

    Ning Chao

    2014-04-01

    Full Text Available A frequency-domain method is proposed for wideband radar echo simulation of high-speed moving targets. Based on the physical process of electromagnetic waves observing a moving target, a frequency-domain echo model of wideband radar is constructed, and the block diagram of the radar echo simulation in frequency-domain is presented. Then, the impacts of radial velocity and slant range on the matching filtering of LFM radar are analyzed, and some quantitative conclusions on the shift and expansion of the radar profiles are obtained. Simulation results illustrate the correctness and efficiency of the proposed method.

  4. Safety features in nuclear power plants to eliminate the need of emergency planning in public domain

    Indian Academy of Sciences (India)

    P K Vijayan; M T Kamble; A K Nayak; K K Vaze; R K Sinha

    2013-10-01

    Following the Fukushima accident, the safety features of Nuclear Power Plants (NPP) are being re-examined worldwide including India to demonstrate capabilities to cope with severe accidents. In order to restore public confidence and support for nuclear power, it is felt necessary to design future NPPs with near zero impact outside the plant boundary and thus enabling elimination of emergency planning in public domain. Authors have identified a set of safety features which are needed to be incorporated in advanced reactors to achieve this goal. These features enabling prevention, termination, mitigation and containment of radioactivity for beyond design basis accidents arising from extreme natural events are essential for achieving the goal of elimination of emergency planning in public domain. Inherent safety characteristics, passive and engineered safety features to achieve these functions are discussed in this paper. Present trends and future developments in this direction are also described briefly.

  5. The Optimization of the Local Public Policies’ Development Process Through Modeling And Simulation

    Directory of Open Access Journals (Sweden)

    Minodora URSĂCESCU

    2012-06-01

    Full Text Available The local public policies development in Romania represents an empirically realized measure, the strategic management practices in this domain not being based on a scientific instrument capable to anticipate and evaluate the results of implementing a local public policy in a logic of needs-policies-effects type. Beginning from this motivation, the purpose of the paper resides in the reconceptualization of the public policies process on functioning principles of the dynamic systems with inverse connection, by means of mathematical modeling and techniques simulation. Therefore, the research is oriented in the direction of developing an optimization method for the local public policies development process, using as instruments the mathematical modeling and the techniques simulation. The research’s main results are on the one side constituted by generating a new process concept of the local public policies, and on the other side by proposing the conceptual model of a complex software product which will permit the parameterized modeling in a virtual environment of these policies development process. The informatic product’s finality resides in modeling and simulating each local public policy type, taking into account the respective policy’s characteristics, but also the value of their appliance environment parameters in a certain moment.

  6. Publicly Released Prompt Radiation Spectra Suitable for Nuclear Detonation Simulations

    Science.gov (United States)

    2017-03-01

    emission. During the Hiroshima and Nagasaki bombings, the prompt radiation contributed from 40%-70% of the free-in-air dose depending on distance from...intermediate- and low -yield thermonuclear weapons for initial radiation shielding calculations No Gritzner, et al. 1976 (EM-1, Low , Henre...Publicly Released Prompt Radiation Spectra Suitable for Nuclear Detonation Simulations DISTRIBUTION A. Approved for public release; distribution is

  7. 37 CFR 201.26 - Recordation of documents pertaining to computer shareware and donation of public domain computer...

    Science.gov (United States)

    2010-07-01

    ... pertaining to computer shareware and donation of public domain computer software. 201.26 Section 201.26... GENERAL PROVISIONS § 201.26 Recordation of documents pertaining to computer shareware and donation of public domain computer software. (a) General. This section prescribes the procedures for submission of...

  8. 32 CFR 644.24 - Acquisition by Transfer from other Government Departments or Agencies (except Public Domain).

    Science.gov (United States)

    2010-07-01

    ... Departments or Agencies (except Public Domain). 644.24 Section 644.24 National Defense Department of Defense... Departments or Agencies (except Public Domain). When a requirement develops for the acquisition of Government... of existing improvements, the estimated cost of the proposed construction, attitude of the...

  9. Effects of Atomistic Domain Size on Hybrid Lattice Boltzmann-Molecular Dynamics Simulations of Dense Fluids

    Science.gov (United States)

    Dupuis, A.; Koumoutsakos, P.

    We present a convergence study for a hybrid Lattice Boltzmann-Molecular Dynamics model for the simulation of dense liquids. Time and length scales are decoupled by using an iterative Schwarz domain decomposition algorithm. The velocity field from the atomistic domain is introduced as forcing terms to the Lattice Boltzmann model of the continuum while the mean field of the continuum imposes mean field conditions for the atomistic domain. In the present paper we investigate the effect of varying the size of the atomistic subdomain in simulations of two dimensional flows of liquid argon past carbon nanotubes and assess the efficiency of the method.

  10. Seismic Response of Wind Turbines: Time Domain Simulations Including SSI

    OpenAIRE

    Amdal, Åse Marit Wist

    2014-01-01

    In this study, a numerical model of a 5MW offshore wind turbine on a monopile foundation was created in order to calculate the dynamic response of the structure including soil-structure interaction. The main focus was to develop a reliable numerical model of the coupled system - including the tower, monopile foundation and the surrounding soil. The wind turbine was subjected to earthquake load in the time-domain. The global response of the wind turbine was compared for the two prevalent meth...

  11. Stability of the beta-sheet of the WW domain: A molecular dynamics simulation study.

    Science.gov (United States)

    Ibragimova, G T; Wade, R C

    1999-10-01

    The WW domain consists of approximately 40 residues, has no disulfide bridges, and forms a three-stranded antiparallel beta-sheet that is monomeric in solution. It thus provides a model system for studying beta-sheet stability in native proteins. We performed molecular dynamics simulations of two WW domains, YAP65 and FBP28, with very different stability characteristics, in order to explore the initial unfolding of the beta-sheet. The less stable YAP domain is much more sensitive to simulation conditions than the FBP domain. Under standard simulation conditions in water (with or without charge-balancing counterions) at 300 K, the beta-sheet of the YAP WW domain disintegrated at early stages of the simulations. Disintegration commenced with the breakage of a hydrogen bond between the second and third strands of the beta-sheet due to an anticorrelated transition of the Tyr-28 psi and Phe-29 phi angles. Electrostatic interactions play a role in this event, and the YAP WW domain structure is more stable when simulated with a complete explicit model of the surrounding ionic strength. Other factors affecting stability of the beta-sheet are side-chain packing, the conformational entropy of the flexible chain termini, and the binding of cognate peptide.

  12. Towards development of a high quality public domain global roads database

    Directory of Open Access Journals (Sweden)

    Andrew Nelson

    2006-12-01

    Full Text Available There is clear demand for a global spatial public domain roads data set with improved geographic and temporal coverage, consistent coding of road types, and clear documentation of sources. The currently best available global public domain product covers only one-quarter to one-third of the existing road networks, and this varies considerably by region. Applications for such a data set span multiple sectors and would be particularly valuable for the international economic development, disaster relief, and biodiversity conservation communities, not to mention national and regional agencies and organizations around the world. The building blocks for such a global product are available for many countries and regions, yet thus far there has been neither strategy nor leadership for developing it. This paper evaluates the best available public domain and commercial data sets, assesses the gaps in global coverage, and proposes a number of strategies for filling them. It also identifies stakeholder organizations with an interest in such a data set that might either provide leadership or funding for its development. It closes with a proposed set of actions to begin the process.

  13. Molecular dynamics simulations from putative transition states of alpha-spectrin SH3 domain

    NARCIS (Netherlands)

    Periole, Xavier; Vendruscolo, Michele; Mark, Alan E.

    2007-01-01

    A series of molecular dynamics simulations in explicit solvent were started from nine structural models of the transition state of the SH3 domain of alpha-spectrin, which were generated by Lindorff Larsen et al. (Nat Struct Mol Biol 2004;11:443-449) using molecular dynamics simulations in which expe

  14. Publicly Releasing a Large Simulation Dataset with NDS Labs

    Science.gov (United States)

    Goldbaum, Nathan

    2016-03-01

    Optimally, all publicly funded research should be accompanied by the tools, code, and data necessary to fully reproduce the analysis performed in journal articles describing the research. This ideal can be difficult to attain, particularly when dealing with large (>10 TB) simulation datasets. In this lightning talk, we describe the process of publicly releasing a large simulation dataset to accompany the submission of a journal article. The simulation was performed using Enzo, an open source, community-developed N-body/hydrodynamics code and was analyzed using a wide range of community- developed tools in the scientific Python ecosystem. Although the simulation was performed and analyzed using an ecosystem of sustainably developed tools, we enable sustainable science using our data by making it publicly available. Combining the data release with the NDS Labs infrastructure allows a substantial amount of added value, including web-based access to analysis and visualization using the yt analysis package through an IPython notebook interface. In addition, we are able to accompany the paper submission to the arXiv preprint server with links to the raw simulation data as well as interactive real-time data visualizations that readers can explore on their own or share with colleagues during journal club discussions. It is our hope that the value added by these services will substantially increase the impact and readership of the paper.

  15. Comparing allosteric transitions in the domains of calmodulin through coarse-grained simulations.

    Science.gov (United States)

    Nandigrami, Prithviraj; Portman, John J

    2016-03-14

    Calmodulin (CaM) is a ubiquitous Ca(2+)-binding protein consisting of two structurally similar domains with distinct stabilities, binding affinities, and flexibilities. We present coarse grained simulations that suggest that the mechanism for the domain's allosteric transitions between the open and closed conformations depends on subtle differences in the folded state topology of the two domains. Throughout a wide temperature range, the simulated transition mechanism of the N-terminal domain (nCaM) follows a two-state transition mechanism while domain opening in the C-terminal domain (cCaM) involves unfolding and refolding of the tertiary structure. The appearance of the unfolded intermediate occurs at a higher temperature in nCaM than it does in cCaM consistent with nCaM's higher thermal stability. Under approximate physiological conditions, the simulated unfolded state population of cCaM accounts for 10% of the population with nearly all of the sampled transitions (approximately 95%) unfolding and refolding during the conformational change. Transient unfolding significantly slows the domain opening and closing rates of cCaM, which can potentially influence its Ca(2+)-binding mechanism.

  16. Comparing allosteric transitions in the domains of calmodulin through coarse-grained simulations

    CERN Document Server

    Nandigrami, Prithviraj

    2015-01-01

    Calmodulin (CaM) is a ubiquitous calcium binding protein consisting of two structurally similar domains with distinct stabilities, binding affinities, and flexibilities. We present coarse grained simulations that suggest the mechanism for the domain's allosteric transitions between the open and closed conformations depend on subtle differences in the folded state topology of the two domains. Throughout a wide temperature range, the simulated transition mechanism of the N-terminal domain (nCaM) follows a two-state transition mechanism while domain opening in the C-terminal domain (cCaM) involves unfolding and refolding of the tertiary structure. The appearance of the unfolded intermediate occurs at a higher temperature in nCaM than it does in cCaM. That is, we find that cCaM unfolds more readily along the transition route than nCaM. Furthermore, unfolding and refolding of the domain significantly slows the domain opening and closing rates of cCaM, a distinct scenario which can potentially influence the mechani...

  17. Simulation of DLA grating structures in the frequency domain

    Science.gov (United States)

    Egenolf, T.; Boine-Frankenheim, O.; Niedermayer, U.

    2017-07-01

    Dielectric laser accelerators (DLA) driven by ultrashort laser pulses can reach orders of magnitude larger gradients than contemporary RF electron accelerators. A new implemented field solver based on the finite element method in the frequency domain allows the efficient calculation of the structure constant, i.e. the ratio of energy gain to laser peak amplitude. We present the maximization of this ratio as a parameter study looking at a single grating period only. Based on this optimized shape the entire design of a beta-matched grating is completed in an iterative process. The period length of a beta-matched grating increases due to the increasing velocity of the electron when a subrelativistic beam is accelerated. The determination of the optimal length of each grating period thus requires the knowledge of the energy gain within all so far crossed periods. Furthermore, we outline to reverse the excitation in the presented solver for beam coupling impedance calculations and an estimation of the beam loading intensity limit.

  18. Magnetic domain patterns on strong perpendicular magnetization of Co/Ni multilayers as spintronics materials: II. Numerical simulations.

    Science.gov (United States)

    Kudo, Kazue; Suzuki, Masahiko; Kojima, Kazuki; Yasue, Tsuneo; Akutsu, Noriko; Diño, Wilson Agerico; Kasai, Hideaki; Bauer, Ernst; Koshikawa, Takanori

    2013-10-02

    Magnetic domains in ultrathin films form domain patterns, which strongly depend on the magnetic anisotropy. The magnetic anisotropy in Co/Ni multilayers changes with the number of layers. We provide a model to simulate the experimentally observed domain patterns. The model assumes a layer-dependent magnetic anisotropy. With the anisotropy parameter estimated from experimental data, we reproduce the magnetic domain patterns.

  19. Finesse, Frequency domain INterferomEter Simulation SoftwarE

    CERN Document Server

    Freise, Andreas; Bond, Charlotte

    2013-01-01

    Finesse is a fast interferometer simulation program. For a given optical setup, it computes the light field amplitudes at every point in the interferometer assuming a steady state. To do so, the interferometer description is translated into a set of linear equations that are solved numerically. For convenience, a number of standard analyses can be performed automatically by the program, namely computing modulation-demodulation error signals, transfer functions, shot-noise-limited sensitivities, and beam shapes. Finesse can perform the analysis using the plane-wave approximation or Hermite-Gauss modes. The latter allows computation of the properties of optical systems like telescopes and the effects of mode matching and mirror angular positions.

  20. Automatic calibration of damping layers in finite element time domain simulations

    OpenAIRE

    Vandekerckhove, Steven; Wells, Garth N.; De Gersem, Herbert; Abeele, Koen Van Den

    2016-01-01

    Matched layers are commonly used in numerical simulations of wave propagation to model (semi-)infinite domains. Attenuation functions describe the damping in layers, and provide a matching of the wave impedance at the interface between the domain of interest and the absorbing region. Selecting parameters in the attenuation functions is non-trivial. In this work, an optimisation procedure for automatically calibrating matched layers is presented. The procedure is based on solving optimisation ...

  1. analysis of large electromagnetic pulse simulators using the electric field integral equation method in time domain

    CERN Document Server

    Jamali, J; Moini, R; Sadeghi, H

    2002-01-01

    A time-domain approach is presented to calculate electromagnetic fields inside a large Electromagnetic Pulse (EMP) simulator. This type of EMP simulator is used for studying the effect of electromagnetic pulses on electrical apparatus in various structures such as vehicles, a reoplanes, etc. The simulator consists of three planar transmission lines. To solve the problem, we first model the metallic structure of the simulator as a grid of conducting wires. The numerical solution of the governing electric field integral equation is then obtained using the method of moments in time domain. To demonstrate the accuracy of the model, we consider a typical EMP simulator. The comparison of our results with those obtained experimentally in the literature validates the model introduced in this paper.

  2. Molecular scaffold analysis of natural products databases in the public domain.

    Science.gov (United States)

    Yongye, Austin B; Waddell, Jacob; Medina-Franco, José L

    2012-11-01

    Natural products represent important sources of bioactive compounds in drug discovery efforts. In this work, we compiled five natural products databases available in the public domain and performed a comprehensive chemoinformatic analysis focused on the content and diversity of the scaffolds with an overview of the diversity based on molecular fingerprints. The natural products databases were compared with each other and with a set of molecules obtained from in-house combinatorial libraries, and with a general screening commercial library. It was found that publicly available natural products databases have different scaffold diversity. In contrast to the common concept that larger libraries have the largest scaffold diversity, the largest natural products collection analyzed in this work was not the most diverse. The general screening library showed, overall, the highest scaffold diversity. However, considering the most frequent scaffolds, the general reference library was the least diverse. In general, natural products databases in the public domain showed low molecule overlap. In addition to benzene and acyclic compounds, flavones, coumarins, and flavanones were identified as the most frequent molecular scaffolds across the different natural products collections. The results of this work have direct implications in the computational and experimental screening of natural product databases for drug discovery.

  3. Stability of the beta-sheet of the WW domain: A molecular dynamics simulation study.

    OpenAIRE

    Ibragimova, G T; Wade, R C

    1999-01-01

    The WW domain consists of approximately 40 residues, has no disulfide bridges, and forms a three-stranded antiparallel beta-sheet that is monomeric in solution. It thus provides a model system for studying beta-sheet stability in native proteins. We performed molecular dynamics simulations of two WW domains, YAP65 and FBP28, with very different stability characteristics, in order to explore the initial unfolding of the beta-sheet. The less stable YAP domain is much more sensitive to simulatio...

  4. Self-consistent field theory simulations of polymers on arbitrary domains

    Science.gov (United States)

    Ouaknin, Gaddiel; Laachi, Nabil; Delaney, Kris; Fredrickson, Glenn H.; Gibou, Frederic

    2016-12-01

    We introduce a framework for simulating the mesoscale self-assembly of block copolymers in arbitrary confined geometries subject to Neumann boundary conditions. We employ a hybrid finite difference/volume approach to discretize the mean-field equations on an irregular domain represented implicitly by a level-set function. The numerical treatment of the Neumann boundary conditions is sharp, i.e. it avoids an artificial smearing in the irregular domain boundary. This strategy enables the study of self-assembly in confined domains and enables the computation of physically meaningful quantities at the domain interface. In addition, we employ adaptive grids encoded with Quad-/Oc-trees in parallel to automatically refine the grid where the statistical fields vary rapidly as well as at the boundary of the confined domain. This approach results in a significant reduction in the number of degrees of freedom and makes the simulations in arbitrary domains using effective boundary conditions computationally efficient in terms of both speed and memory requirement. Finally, in the case of regular periodic domains, where pseudo-spectral approaches are superior to finite differences in terms of CPU time and accuracy, we use the adaptive strategy to store chain propagators, reducing the memory footprint without loss of accuracy in computed physical observables.

  5. Dynamic Simulations of Nonlinear Multi-Domain Systems Based on Genetic Programming and Bond Graphs

    Institute of Scientific and Technical Information of China (English)

    DI Wenhui; SUN Bo; XU Lixin

    2009-01-01

    A dynamic simulation method for non-linear systems based on genetic programming (GP) and bond graphs (BG) was developed to improve the design of nonlinear multi-domain energy conversion sys-tems. The genetic operators enable the embryo bond graph to evolve towards the target graph according to the fitness function. Better simulation requires analysis of the optimization of the eigenvalue and the filter circuit evolution. The open topological design and space search ability of this method not only gives a more optimized convergence for the operation, but also reduces the generation time for the new circuit graph for the design of nonlinear multi-domain systems.

  6. Daas: A Web-based System for User-specific Dietary Analysis and Advice for the Public Healthcare Domain

    Institute of Scientific and Technical Information of China (English)

    Deirdre Nugent; Kudakwashe Dube; Wu Bing

    2003-01-01

    This paper presents a Dietary Analysis and Advice System (DAAS), a web-based system for providing, within the public healthcare domain, user-specific diet advice based on a preliminary analysis of current diet or eating habits and lifestyle, using knowledge from domain expertise and experts' interpretation of national dietary guidelines.

  7. Accurate Behavioral Simulator of All-Digital Time-Domain Smart Temperature Sensors by Using SIMULINK

    Directory of Open Access Journals (Sweden)

    Chun-Chi Chen

    2016-08-01

    Full Text Available This study proposes a new behavioral simulator that uses SIMULINK for all-digital CMOS time-domain smart temperature sensors (TDSTSs for performing rapid and accurate simulations. Inverter-based TDSTSs offer the benefits of low cost and simple structure for temperature-to-digital conversion and have been developed. Typically, electronic design automation tools, such as HSPICE, are used to simulate TDSTSs for performance evaluations. However, such tools require extremely long simulation time and complex procedures to analyze the results and generate figures. In this paper, we organize simple but accurate equations into a temperature-dependent model (TDM by which the TDSTSs evaluate temperature behavior. Furthermore, temperature-sensing models of a single CMOS NOT gate were devised using HSPICE simulations. Using the TDM and these temperature-sensing models, a novel simulator in SIMULINK environment was developed to substantially accelerate the simulation and simplify the evaluation procedures. Experiments demonstrated that the simulation results of the proposed simulator have favorable agreement with those obtained from HSPICE simulations, showing that the proposed simulator functions successfully. This is the first behavioral simulator addressing the rapid simulation of TDSTSs.

  8. Accurate Behavioral Simulator of All-Digital Time-Domain Smart Temperature Sensors by Using SIMULINK.

    Science.gov (United States)

    Chen, Chun-Chi; Chen, Chao-Lieh; Lin, You-Ting

    2016-08-08

    This study proposes a new behavioral simulator that uses SIMULINK for all-digital CMOS time-domain smart temperature sensors (TDSTSs) for performing rapid and accurate simulations. Inverter-based TDSTSs offer the benefits of low cost and simple structure for temperature-to-digital conversion and have been developed. Typically, electronic design automation tools, such as HSPICE, are used to simulate TDSTSs for performance evaluations. However, such tools require extremely long simulation time and complex procedures to analyze the results and generate figures. In this paper, we organize simple but accurate equations into a temperature-dependent model (TDM) by which the TDSTSs evaluate temperature behavior. Furthermore, temperature-sensing models of a single CMOS NOT gate were devised using HSPICE simulations. Using the TDM and these temperature-sensing models, a novel simulator in SIMULINK environment was developed to substantially accelerate the simulation and simplify the evaluation procedures. Experiments demonstrated that the simulation results of the proposed simulator have favorable agreement with those obtained from HSPICE simulations, showing that the proposed simulator functions successfully. This is the first behavioral simulator addressing the rapid simulation of TDSTSs.

  9. Open access high throughput drug discovery in the public domain: a Mount Everest in the making.

    Science.gov (United States)

    Roy, Anuradha; McDonald, Peter R; Sittampalam, Sitta; Chaguturu, Rathnam

    2010-11-01

    High throughput screening (HTS) facilitates screening large numbers of compounds against a biochemical target of interest using validated biological or biophysical assays. In recent years, a significant number of drugs in clinical trails originated from HTS campaigns, validating HTS as a bona fide mechanism for hit finding. In the current drug discovery landscape, the pharmaceutical industry is embracing open innovation strategies with academia to maximize their research capabilities and to feed their drug discovery pipeline. The goals of academic research have therefore expanded from target identification and validation to probe discovery, chemical genomics, and compound library screening. This trend is reflected in the emergence of HTS centers in the public domain over the past decade, ranging in size from modestly equipped academic screening centers to well endowed Molecular Libraries Probe Centers Network (MLPCN) centers funded by the NIH Roadmap initiative. These centers facilitate a comprehensive approach to probe discovery in academia and utilize both classical and cutting-edge assay technologies for executing primary and secondary screening campaigns. The various facets of academic HTS centers as well as their implications on technology transfer and drug discovery are discussed, and a roadmap for successful drug discovery in the public domain is presented. New lead discovery against therapeutic targets, especially those involving the rare and neglected diseases, is indeed a Mount Everestonian size task, and requires diligent implementation of pharmaceutical industry's best practices for a successful outcome.

  10. A Systematic Review of Agent-Based Modelling and Simulation Applications in the Higher Education Domain

    Science.gov (United States)

    Gu, X.; Blackmore, K. L.

    2015-01-01

    This paper presents the results of a systematic review of agent-based modelling and simulation (ABMS) applications in the higher education (HE) domain. Agent-based modelling is a "bottom-up" modelling paradigm in which system-level behaviour (macro) is modelled through the behaviour of individual local-level agent interactions (micro).…

  11. Human experimental anxiety: actual public speaking induces more intense physiological responses than simulated public speaking.

    Science.gov (United States)

    Zuardi, Antonio Waldo; Crippa, José Alexandre de Souza; Hallak, Jaime Eduardo Cecílio; Gorayeb, Ricardo

    2013-01-01

    a) To perform a systematic and meta-analytic review to verify whether the Simulated Public Speaking Task (SPST) leads to a greater increase in self-rated anxiety than in physiological correlates of anxiety; and b) to compare the results obtained with the SPST with an actual public speaking task involving healthy volunteers. a) The PubMed and ISI Web of Knowledge databases were searched for studies involving the SPST prior to 2012. Eleven publications were eligible and provided data from 143 healthy volunteers for meta-analysis; b) 48 university students without somatic or psychiatric disorders were divided into three experimental groups of 16 subjects to undergo one of the following: SPST, real-world public speaking task (real-world), and control situation (control). The meta-analysis showed that the SPST induced a significant increase in the Visual Analogue Mood Scale (VAMS) anxiety factor, but no significant increases in systolic blood pressure or heart rate. The empirical study showed that the real-world public speaking task increased heart rate, systolic blood pressure and diastolic blood pressure significantly more than the control and SPST conditions. These results suggest that real public speaking might be better than SPST in inducing experimental anxiety.

  12. Optimized Mooring Line Simulation Using a Hybrid Method Time Domain Scheme

    DEFF Research Database (Denmark)

    Christiansen, Niels Hørbye; Voie, Per Erlend Torbergsen; Høgsberg, Jan;

    2014-01-01

    of mooring lines by two orders of magnitude. The present study shows how an ANN trained to perform nonlinear dynamic response simulation can be optimized using a method known as optimal brain damage (OBD) and thereby be used to rank the importance of all analysis input. Both the training and the optimization...... of the ANN are based on one short time domain simulation sequence generated by a FEM model of the structure. This means that it is possible to evaluate the importance of input parameters based on this single simulation only. The method is tested on a numerical model of mooring lines on a floating offshore...

  13. Shock waves simulated using the dual domain material point method combined with molecular dynamics

    Science.gov (United States)

    Zhang, Duan Z.; Dhakal, Tilak R.

    2017-04-01

    In this work we combine the dual domain material point method with molecular dynamics in an attempt to create a multiscale numerical method to simulate materials undergoing large deformations with high strain rates. In these types of problems, the material is often in a thermodynamically nonequilibrium state, and conventional constitutive relations or equations of state are often not available. In this method, the closure quantities, such as stress, at each material point are calculated from a molecular dynamics simulation of a group of atoms surrounding the material point. Rather than restricting the multiscale simulation in a small spatial region, such as phase interfaces, or crack tips, this multiscale method can be used to consider nonequilibrium thermodynamic effects in a macroscopic domain. This method takes the advantage that the material points only communicate with mesh nodes, not among themselves; therefore molecular dynamics simulations for material points can be performed independently in parallel. The dual domain material point method is chosen for this multiscale method because it can be used in history dependent problems with large deformation without generating numerical noise as material points move across cells, and also because of its convergence and conservation properties. To demonstrate the feasibility and accuracy of this method, we compare the results of a shock wave propagation in a cerium crystal calculated using the direct molecular dynamics simulation with the results from this combined multiscale calculation.

  14. A Multi Level Multi Domain Method for Particle In Cell Plasma Simulations

    CERN Document Server

    Innocenti, M E; Markidis, S; Beck, A; Vapirev, A

    2012-01-01

    A novel adaptive technique for electromagnetic Particle In Cell (PIC) plasma simulations is presented here. Two main issues are identified in designing adaptive techniques for PIC simulation: first, the choice of the size of the particle shape function in progressively refined grids, with the need to avoid the exertion of self-forces on particles, and, second, the necessity to comply with the strict stability constraints of the explicit PIC algorithm. The adaptive implementation presented responds to these demands with the introduction of a Multi Level Multi Domain (MLMD) system (where a cloud of self-similar domains is fully simulated with both fields and particles) and the use of an Implicit Moment PIC method as baseline algorithm for the adaptive evolution. Information is exchanged between the levels with the projection of the field information from the refined to the coarser levels and the interpolation of the boundary conditions for the refined levels from the coarser level fields. Particles are bound to...

  15. Frequency Domain Modeling and Simulation of DC Power Electronic Systems Using Harmonic State Space Method

    DEFF Research Database (Denmark)

    Kwon, Jun Bum; Wang, Xiongfei; Blaabjerg, Frede

    2016-01-01

    For the efficiency and simplicity of electric systems, the dc power electronic systems are widely used in a variety of applications such as electric vehicles, ships, aircraft and also in homes. In these systems, there could be a number of dynamic interactions and frequency coupling between network...... with different switching frequency or harmonics from ac-dc converters makes that harmonics and frequency coupling are both problems of ac system and challenges of dc system. This paper presents a modeling and simulation method for a large dc power electronic system by using Harmonic State Space (HSS) modeling...... and loads and other converters. Hence, time-domain simulations are usually required to consider such a complex system behavior. However, simulations in the time-domain may increase the calculation time and the utilization of computer memory. Furthermore, frequency coupling driven by multiple converters...

  16. Time and Frequency-Domain Cross-Verification of SLS 6DOF Trajectory Simulations

    Science.gov (United States)

    Johnson, Matthew; McCullough, John

    2017-01-01

    The Space Launch System (SLS) Guidance, Navigation, and Control (GNC) team and its partners have developed several time- and frequency-based simulations for development and analysis of the proposed SLS launch vehicle. The simulations differ in fidelity and some have unique functionality that allows them to perform specific analyses. Some examples of the purposes of the various models are: trajectory simulation, multi-body separation, Monte Carlo, hardware in the loop, loads, and frequency domain stability analyses. While no two simulations are identical, many of the models are essentially six degree-of-freedom (6DOF) representations of the SLS plant dynamics, hardware implementation, and flight software. Thus at a high level all of those models should be in agreement. Comparison of outputs from several SLS trajectory and stability analysis tools are ongoing as part of the program's current verification effort. The purpose of these comparisons is to highlight modeling and analysis differences, verify simulation data sources, identify inconsistencies and minor errors, and ultimately to verify output data as being a good representation of the vehicle and subsystem dynamics. This paper will show selected verification work in both the time and frequency domain from the current design analysis cycle of the SLS for several of the design and analysis simulations. In the time domain, the tools that will be compared are MAVERIC, CLVTOPS, SAVANT, STARS, ARTEMIS, and POST 2. For the frequency domain analysis, the tools to be compared are FRACTAL, SAVANT, and STARS. The paper will include discussion of these tools including their capabilities, configurations, and the uses to which they are put in the SLS program. Determination of the criteria by which the simulations are compared (matching criteria) requires thoughtful consideration, and there are several pitfalls that may occur that can severely punish a simulation if not considered carefully. The paper will discuss these

  17. Time and Frequency-Domain Cross-Verification of SLS 6DOF Trajectory Simulations

    Science.gov (United States)

    VanZwieten, Tannen; Johnson, Matthew D.; McCullough, John P.; Gilligan, Eric T.

    2014-01-01

    The SLS GNC team and its partners have developed several time- and frequency-based simulations for development and analysis of the proposed SLS launch vehicle. The simulations differ in fidelity and some have unique functionality that allows them to perform specific analyses. Some examples of the purposes of the various models are: trajectory simulation, multi-body separation, Monte Carlo, hardware in the loop, loads, and frequency domain stability analyses. While no two simulations are identical, many of the models are essentially six degree-of-freedom (6DOF) representations of the SLS plant dynamics, hardware implementation, and flight software. Thus at a high level all of those models should be in agreement. Comparison of outputs from several SLS trajectory and stability analysis tools are ongoing as part of the program's current verification effort. The purpose of these comparisons is to highlight modeling and analysis differences, verify simulation data sources, identify inconsistencies and minor errors, and ultimately to verify output data as being a good representation of the vehicle and subsystem dynamics. This paper will show selected verification work in both the time and frequency domain from the current design analysis cycle of the SLS for several of the design and analysis simulations. In the time domain, the tools that will be compared are MAVERIC, CLVTOPS, SAVANT, STARS, ARTEMIS, and POST 2. For the frequency domain analysis, the tools to be compared are FRACTAL, SAVANT, and STARS. The paper will include discussion of these tools including their capabilities, configurations, and the uses to which they are put in the SLS program. Determination of the criteria by which the simulations are compared (matching criteria) requires thoughtful consideration, and there are several pitfalls that may occur that can severely punish a simulation if not considered carefully. The paper will discuss these considerations and will present a framework for responding to

  18. An Entropy Approach to Disclosure Risk Assessment: Lessons from Real Applications and Simulated Domains

    Science.gov (United States)

    Airoldi, Edoardo M.; Bai, Xue; Malin, Bradley A.

    2011-01-01

    We live in an increasingly mobile world, which leads to the duplication of information across domains. Though organizations attempt to obscure the identities of their constituents when sharing information for worthwhile purposes, such as basic research, the uncoordinated nature of such environment can lead to privacy vulnerabilities. For instance, disparate healthcare providers can collect information on the same patient. Federal policy requires that such providers share “de-identified” sensitive data, such as biomedical (e.g., clinical and genomic) records. But at the same time, such providers can share identified information, devoid of sensitive biomedical data, for administrative functions. On a provider-by-provider basis, the biomedical and identified records appear unrelated, however, links can be established when multiple providers’ databases are studied jointly. The problem, known as trail disclosure, is a generalized phenomenon and occurs because an individual’s location access pattern can be matched across the shared databases. Due to technical and legal constraints, it is often difficult to coordinate between providers and thus it is critical to assess the disclosure risk in distributed environments, so that we can develop techniques to mitigate such risks. Research on privacy protection has so far focused on developing technologies to suppress or encrypt identifiers associated with sensitive information. There is growing body of work on the formal assessment of the disclosure risk of database entries in publicly shared databases, but a less attention has been paid to the distributed setting. In this research, we review the trail disclosure problem in several domains with known vulnerabilities and show that disclosure risk is influenced by the distribution of how people visit service providers. Based on empirical evidence, we propose an entropy metric for assessing such risk in shared databases prior to their release. This metric assesses risk by

  19. Finite-Difference Time-Domain Simulation for Three-dimensional Polarized Light Imaging

    CERN Document Server

    Menzel, Miriam; De Raedt, Hans; Michielsen, Kristel

    2016-01-01

    Three-dimensional Polarized Light Imaging (3D-PLI) is a promising technique to reconstruct the nerve fiber architecture of human post-mortem brains from birefringence measurements of histological brain sections with micrometer resolution. To better understand how the reconstructed fiber orientations are related to the underlying fiber structure, numerical simulations are employed. Here, we present two complementary simulation approaches that reproduce the entire 3D-PLI analysis: First, we give a short review on a simulation approach that uses the Jones matrix calculus to model the birefringent myelin sheaths. Afterwards, we introduce a more sophisticated simulation tool: a 3D Maxwell solver based on a Finite-Difference Time-Domain algorithm that simulates the propagation of the electromagnetic light wave through the brain tissue. We demonstrate that the Maxwell solver is a valuable tool to better understand the interaction of polarized light with brain tissue and to enhance the accuracy of the fiber orientati...

  20. A Linked-Cell Domain Decomposition Method for Molecular Dynamics Simulation on a Scalable Multiprocessor

    Directory of Open Access Journals (Sweden)

    L.H. Yang

    1992-01-01

    Full Text Available A molecular dynamics algorithm for performing large-scale simulations using the Parallel C Preprocessor (PCP programming paradigm on the BBN TC2000, a massively parallel computer, is discussed. The algorithm uses a linked-cell data structure to obtain the near neighbors of each atom as time evoles. Each processor is assigned to a geometric domain containing many subcells and the storage for that domain is private to the processor. Within this scheme, the interdomain (i.e., interprocessor communication is minimized.

  1. Simulation of power fluctuation of wind farms based on frequency domain

    DEFF Research Database (Denmark)

    Lin, Jin; Sun, Yuanzhang; Li, Guojie

    2011-01-01

    With the capacity of installed wind power generators steadily increasing in China, power fluctuation from wind farms will significantly affect the security and reliability of the power system. Traditional modeling of power fluctuation is based on the time domain or statistics methodology which...... the power spectral density of wind speed, the frequency domain model of a wind power generator and the information on weather and geography of the wind farms. The correctness and effectiveness of the model are verified by comparing the measurement data with simulation results of a certain wind farm. © 2011...

  2. The Creative Commons. A Third Way between Public Domain and Community ?

    Directory of Open Access Journals (Sweden)

    Clément Bert-Erboul

    2016-04-01

    Full Text Available How have the Creative Commons’ ownership rules used by free websites like Wikipedia or Flickr and in 3D printer projects or in alternative kitchen gardens, been develo­ped? Internet users and technological experimentation communities rely heavily on these free tools, but the ideologies of the public domain and online communities that allowed their birth often remain obscure. In this article we used American legal doctri­ne, the scientific literature and specialized press archives. From these sources we analyzed the links between Copyright reforms and the institutionalization of the activity of free software developers, at the origin of Creative Commons licenses. The case of intangible goods property applied to tangibles goods shows how the community members and institutions legitimize their IT practices by means of several producers of norms, such as States or communities.

  3. Systematic analysis of public domain compound potency data identifies selective molecular scaffolds across druggable target families.

    Science.gov (United States)

    Hu, Ye; Wassermann, Anne Mai; Lounkine, Eugen; Bajorath, Jürgen

    2010-01-28

    Molecular scaffolds that yield target family-selective compounds are of high interest in pharmaceutical research. There continues to be considerable debate in the field as to whether chemotypes with a priori selectivity for given target families and/or targets exist and how they might be identified. What do currently available data tell us? We present a systematic and comprehensive selectivity-centric analysis of public domain target-ligand interactions. More than 200 molecular scaffolds are identified in currently available active compounds that are selective for established target families. A subset of these scaffolds is found to produce compounds with high selectivity for individual targets among closely related ones. These scaffolds are currently underrepresented in approved drugs.

  4. Ferrimagnetic/ferroelastic domain interactions in magnetite below the Verwey transition: Part II. Micromagnetic and image simulations

    DEFF Research Database (Denmark)

    Bryson, James F.J.; Kasama, Takeshi; Dunin-Borkowski, Rafal E.;

    2013-01-01

    Micromagnetic simulations have been used to explore the interaction between ferrimagnetic domain walls (DWs) and ferroelastic twin walls (TWs) below the Verwey transition in magnetite (Fe3O4). Simulations were performed using a thin-foil geometry in order to replicate the domain patterns observed...

  5. Fast resolution of the neutron diffusion equation through public domain Ode codes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, V.M.; Vidal, V.; Garayoa, J. [Universidad Politecnica de Valencia, Departamento de Sistemas Informaticos, Valencia (Spain); Verdu, G. [Universidad Politecnica de Valencia, Departamento de Ingenieria Quimica y Nuclear, Valencia (Spain); Gomez, R. [I.E.S. de Tavernes Blanques, Valencia (Spain)

    2003-07-01

    The time-dependent neutron diffusion equation is a partial differential equation with source terms. The resolution method usually includes discretizing the spatial domain, obtaining a large system of linear, stiff ordinary differential equations (ODEs), whose resolution is computationally very expensive. Some standard techniques use a fixed time step to solve the ODE system. This can result in errors (if the time step is too large) or in long computing times (if the time step is too little). To speed up the resolution method, two well-known public domain codes have been selected: DASPK and FCVODE that are powerful codes for the resolution of large systems of stiff ODEs. These codes can estimate the error after each time step, and, depending on this estimation can decide which is the new time step and, possibly, which is the integration method to be used in the next step. With these mechanisms, it is possible to keep the overall error below the chosen tolerances, and, when the system behaves smoothly, to take large time steps increasing the execution speed. In this paper we address the use of the public domain codes DASPK and FCVODE for the resolution of the time-dependent neutron diffusion equation. The efficiency of these codes depends largely on the preconditioning of the big systems of linear equations that must be solved. Several pre-conditioners have been programmed and tested; it was found that the multigrid method is the best of the pre-conditioners tested. Also, it has been found that DASPK has performed better than FCVODE, being more robust for our problem.We can conclude that the use of specialized codes for solving large systems of ODEs can reduce drastically the computational work needed for the solution; and combining them with appropriate pre-conditioners, the reduction can be still more important. It has other crucial advantages, since it allows the user to specify the allowed error, which cannot be done in fixed step implementations; this, of course

  6. Large Scale Simulation of Hydrogen Dispersion by a Stabilized Balancing Domain Decomposition Method

    Directory of Open Access Journals (Sweden)

    Qing-He Yao

    2014-01-01

    Full Text Available The dispersion behaviour of leaking hydrogen in a partially open space is simulated by a balancing domain decomposition method in this work. An analogy of the Boussinesq approximation is employed to describe the connection between the flow field and the concentration field. The linear systems of Navier-Stokes equations and the convection diffusion equation are symmetrized by a pressure stabilized Lagrange-Galerkin method, and thus a balancing domain decomposition method is enabled to solve the interface problem of the domain decomposition system. Numerical results are validated by comparing with the experimental data and available numerical results. The dilution effect of ventilation is investigated, especially at the doors, where flow pattern is complicated and oscillations appear in the past research reported by other researchers. The transient behaviour of hydrogen and the process of accumulation in the partially open space are discussed, and more details are revealed by large scale computation.

  7. Accelerating mono-domain cardiac electrophysiology simulations using OpenCL

    Directory of Open Access Journals (Sweden)

    Wülfers Eike M.

    2015-09-01

    Full Text Available Using OpenCL, we developed a cross-platform software to compute electrical excitation conduction in cardiac tissue. OpenCL allowed the software to run parallelized and on different computing devices (e.g., CPUs and GPUs. We used the macroscopic mono-domain model for excitation conduction and an atrial myocyte model by Courtemanche et al. for ionic currents. On a CPU with 12 HyperThreading-enabled Intel Xeon 2.7 GHz cores, we achieved a speed-up of simulations by a factor of 1.6 against existing software that uses OpenMPI. On two high-end AMD FirePro D700 GPUs the OpenCL software ran 2.4 times faster than the OpenMPI implementation. The more nodes the discretized simulation domain contained, the higher speed-ups were achieved.

  8. Simulation on Domain Rotation Path and Magnetostriction of Terfenol-D Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on a simplified domain rotation model, the rotation path of internal domains and corresponding magnetostriction of <112>, <111> oriented single Terfenol-D crystals under compressive prestresses have been simulated. Comparisons with results of experiment and other calculation have been made. Results of simulation showed that the <111> oriented single crystal has better Iow-field magnetostriction properties than the <112> oriented one. Under a compressive prestress of 10 MPa, up to 2300×10-6 saturation magnetostriction of <111>oriented crystal has been obtained at 800 Oe, while for <112> oriented, 1600×10-6 maximum magnetostriction has been reached at 1000 Oe.

  9. Fast simulation approaches for power fluctuation model of wind farm based on frequency domain

    DEFF Research Database (Denmark)

    Lin, Jin; Gao, Wen-zhong; Sun, Yuan-zhang

    2012-01-01

    This paper discusses one model developed by Riso, DTU, which is capable of simulating the power fluctuation of large wind farms in frequency domain. In the original design, the “frequency-time” transformations are time-consuming and might limit the computation speed for a wind farm of large size....... is more than 300 times if all these approaches are adopted, in any low, medium and high wind speed test scenarios....

  10. A domain decomposition method for the efficient direct simulation of aeroacoustic problems

    OpenAIRE

    Utzmann, Jens

    2008-01-01

    A novel domain decomposition approach is developed in this thesis, which significantly accelerates the direct simulation of aeroacoustic problems. All relevant scales must be resolved with high accuracy, from the small, noise generating flow features (e.g., vortices) to the sound with small pressure amplitudes and large wavelengths. Furthermore, the acoustic waves must be propagated over great distances and without dissipation and dispersion errors. In order to keep the computational effort w...

  11. Simulation of acoustic streaming by means of the finite-difference time-domain method

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco

    2012-01-01

    the finite-difference time-domain method. To simplify the problem, thermal effects are not considered. The motivation of the described investigation has been the possibility of using the numerical method to study acoustic streaming, particularly under non-steady conditions. Results are discussed for channels...... of different width, which illustrate the applicability of the method. The obtained numerical simulations agree quite will with analytical solutions available in the literature....

  12. Micromagnetic Simulation of Magnetic Domains in Exchange-coupled Ferromagnetic Thin Films

    Institute of Scientific and Technical Information of China (English)

    WANG; Zi-jun

    2013-01-01

    The reversal process of exchange spring double layers was simulated,investigating the impact of anisotropy constant and film thickness of both hard and soft layer on the magnetic domain structures.We also worked over the magnetization configuration in hard/soft/hard and soft/hard/soft trilayer exchange springs.Changing the anisotropy constant and film thickness of hard and soft layer would greatly impact

  13. Multicanonical Molecular Dynamics Simulations of the N-terminal Domain of Protein L9

    Science.gov (United States)

    Yaşar, Fatih; Jiang, Ping; Hansmann, Ulrich H. E.

    2014-01-01

    We describe multicanonical molecular dynamic simulations of the N-terminal domain of the protein L9. Analyzing free energy landscapes and thermal ordering, we propose a possible folding mechanism for the protein. By comparing our results with that of molecular dynamics runs of the protein at constant temperature, we find that multicanonical molecular dynamics leads to orders of magnitude higher sampling of folding transitions. PMID:25253918

  14. Time-domain hybrid method for simulating large amplitude motions of ships advancing in waves

    Directory of Open Access Journals (Sweden)

    Shukui Liu

    2011-03-01

    Full Text Available Typical results obtained by a newly developed, nonlinear time domain hybrid method for simulating large amplitude motions of ships advancing with constant forward speed in waves are presented. The method is hybrid in the way of combining a time-domain transient Green function method and a Rankine source method. The present approach employs a simple double integration algorithm with respect to time to simulate the free-surface boundary condition. During the simulation, the diffraction and radiation forces are computed by pressure integration over the mean wetted surface, whereas the incident wave and hydrostatic restoring forces/moments are calculated on the instantaneously wetted surface of the hull. Typical numerical results of application of the method to the seakeeping performance of a standard containership, namely the ITTC S175, are herein presented. Comparisons have been made between the results from the present method, the frequency domain 3D panel method (NEWDRIFT of NTUA-SDL and available experimental data and good agreement has been observed for all studied cases between the results of the present method and comparable other data.

  15. An FFT-accelerated time-domain multiconductor transmission line simulator

    KAUST Repository

    Bagci, Hakan

    2010-02-01

    A fast time-domain multiconductor transmission line (MTL) simulator for analyzing general MTL networks is presented. The simulator models the networks as homogeneous MTLs that are excited by external fields and driven/terminated/ connected by potentially nonlinear lumped circuitry. It hybridizes an MTL solver derived from time-domain integral equations (TDIEs) in unknown wave coefficients for each MTL with a circuit solver rooted in modified nodal analysis equations in unknown node voltages and voltage-source currents for each circuit. These two solvers are rigorously interfaced at MTL and circuit terminals, and the resulting coupled system of equations is solved simultaneously for all MTL and circuit unknowns at each time step. The proposed simulator is amenable to hybridization, is fast Fourier transform (FFT)-accelerated, and is highly accurate: 1) It can easily be hybridized with TDIE-based field solvers (in a fully rigorous mathematical framework) for performing electromagnetic interference and compatibility analysis on electrically large and complex structures loaded with MTL networks. 2) It is accelerated by an FFT algorithm that calculates temporal convolutions of time-domain MTL Green functions in only O(Ntlog2 N t) rather than O(Ntt2) operations, where N t is the number of time steps of simulation. Moreover, the algorithm, which operates on temporal samples of MTL Green functions, is indifferent to the method used to obtain them. 3) It approximates MTL voltages, currents, and wave coefficients, using high-order temporal basis functions. Various numerical examples, including the crosstalk analysis of a (twisted) unshielded twisted-pair (UTP)-CAT5 cable and the analysis of field coupling into UTP-CAT5 and RG-58 cables located on an airplane, are presented to demonstrate the accuracy, efficiency, and versatility of the proposed simulator. © 2010 IEEE.

  16. Time-domain simulation for water wave radiation by floating structures (Part A)

    Institute of Scientific and Technical Information of China (English)

    XU Gang; DUAN Wen-yang

    2008-01-01

    Direct time-domain simulation of floating structures has advantages: it can calculate wave pressure fields and forces directly;and it is useful for coupled analysis of floating structures with a mooring system. A time-domain boundary integral equation method is presented to simulate three-dimensional water wave radiation problems. A stable form of the integration free-surface boundary condition (IFBC) is used to update velocity potentials on the free surface. A multi-transmitting formula (MTF) method with an artificial speed is introduced to the artificial radiation boundary (ARB). The method was applied to simulate a semi-spherical liquefied natural gas (LNG) carrier and a semi-submersible undergoing specified harmonic motion. Numerical parameters such as the form of the ARB,and the time and space discretization related to this method are discussed. It was found that a good agreement can be obtained when artificial speed is between 0.6 and 1.6 times the phase velocity of water waves in the MTF method. A simulation can be done for a long period of time by this method without problems of instability,and the method is also accurate and computationally efficient.

  17. Finite difference time domain method forward simulation of complex geoelectricity ground penetrating radar model

    Institute of Scientific and Technical Information of China (English)

    DAI Qian-wei; FENG De-shan; HE Ji-shan

    2005-01-01

    The ground penetrating radar(GPR) forward simulation all aims at the singular and regular models, such as sandwich model, round cavity, square cavity, and so on, which are comparably simple. But as to the forward of curl interface underground or "v" figure complex model, it is difficult to realize. So it is important to forward the complex geoelectricity model. This paper takes two Maxwell's vorticity equations as departure point, makes use of the principles of Yee's space grid model theory and the basic principle finite difference time domain method, and deduces a GPR forward system of equation of two dimensional spaces. The Mur super absorbed boundary condition is adopted to solve the super strong reflection on the interceptive boundary when there is the forward simulation. And a self-made program is used to process forward simulation to two typical geoelectricity model.

  18. Simulation of flow across complicated domain between tube bundles by the discrete vortex method

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    On the basis of the analysis of numerical simulation methods for the complicated domain between tube bundles, an improved Lagragian discrete vortex method (DVM) and corresponding algorithm are put forward to solve the practical difficulties of flow across tube bundles. With this method the amount of vortices can be reduced considerably, which makes quick calculation possible. Applied to the practical configuration of horizontal tube bundles, the DVM simulation is carried out and compared with the experimental results. Both the transient flow field and the profile of mean velocity and fluctuations are in good agreement with experimental results, which indicate that the DVM is suitable for the simulation of single-phase flow across tube bundles.

  19. Domain-growth kinetics and aspects of pinning: A Monte Carlo simulation study

    DEFF Research Database (Denmark)

    Castán, T.; Lindgård, Per-Anker

    1991-01-01

    By means of Monte Carlo computer simulations we study the domain-growth kinetics after a quench across a first-order line to very low and moderate temperatures in a multidegenerate system with nonconserved order parameter. The model is a continuous spin model relevant for martensitic transformati...... the continuous-spin model is reduced to a discrete Potts-like model, with the same parameters, the exponent is found to be consistent with the classical Allen-Cahn exponent n = 1/2.......By means of Monte Carlo computer simulations we study the domain-growth kinetics after a quench across a first-order line to very low and moderate temperatures in a multidegenerate system with nonconserved order parameter. The model is a continuous spin model relevant for martensitic...... transformations, surface reconstructions, and magnetic transitions. No external impurities are introduced, but the model has a number of intrinsic, annealable pinning mechanisms, which strongly influences the growth kinetics. It allows a study of pinning effects of three kinds: (a) pinning of domain walls...

  20. Assessing water availability over peninsular Malaysia using public domain satellite data products

    Science.gov (United States)

    Ali, M. I.; Hashim, M.; Zin, H. S. M.

    2014-02-01

    Water availability monitoring is an essential task for water resource sustainability and security. In this paper, the assessment of satellite remote sensing technique for determining water availability is reported. The water-balance analysis is used to compute the spatio-temporal water availability with main inputs; the precipitation and actual evapotranspiration rate (AET), both fully derived from public-domain satellite products of Tropical Rainfall Measurement Mission (TRMM) and MODIS, respectively. Both these satellite products were first subjected to calibration to suit corresponding selected local precipitation and AET samples. Multi-temporal data sets acquired 2000-2010 were used in this study. The results of study, indicated strong agreement of monthly water availability with the basin flow rate (r2 = 0.5, p < 0.001). Similar agreements were also noted between the estimated annual average water availability with the in-situ measurement. It is therefore concluded that the method devised in this study provide a new alternative for water availability mapping over large area, hence offers the only timely and cost-effective method apart from providing comprehensive spatio-temporal patterns, crucial in water resource planning to ensure water security.

  1. Public domain small-area cancer incidence data for New York State, 2005-2009

    Directory of Open Access Journals (Sweden)

    Francis P. Boscoe

    2016-04-01

    Full Text Available There has long been a demand for cancer incidence data at a fine geographic resolution for use in etiologic hypothesis generation and testing, methodological evaluation and teaching. In this paper we describe a public domain dataset containing data for 23 anatomic sites of cancer diagnosed in New York State, USA between 2005 and 2009 at the census block group level. The dataset includes 524,503 tumours distributed across 13,823 block groups with an average population of about 1400. In addition, the data have been linked with race/ethnicity and with socioeconomic indicators such as income, educational attainment and language proficiency. We demonstrate the application of the dataset by confirming two well-established relationships: that between breast cancer and median household income and that between stomach cancer and Asian race. We foresee that this dataset will serve as the basis for a wide range of spatial analyses and as a benchmark for evaluating spatial methods in the future.

  2. Preserving Madagascar's Natural Heritage: The Importance of Keeping the Island's Vertebrate Fossils in the Public Domain

    Directory of Open Access Journals (Sweden)

    Karen E. Samonds

    2006-12-01

    Full Text Available The origin of Madagascar’s highly endemic vertebrate fauna remains one of the great unsolved mysteries of natural history. From what landmasses did the basal stocks of this unique and imbalanced fauna come? When and how did the ancestral populations arrive on the island? How rapidly did they diversify, and why? The most direct means of addressing these questions, and other enigmas concerning the evolutionary and biogeographic history of Madagascar’s vertebrate fauna, is through discovery of fossils from a sequence of well-dated geological horizons. Many fossils relevant to these queries have been discovered by paleontologists in recent years ... but many more are being lost to commercial enterprises, both foreign and domestic, that have little or no regard for the scientific significance of fossils. The objectives of this essay are to 1 provide an overview of Madagascar’s vertebrate fossil record and its importance, 2 raise awareness concerning the illegal collection, exportation, and sale of vertebrate fossils, and 3 stress the importance of keeping vertebrate fossils from the island in the public domain. In light of these issues, we underscore the necessity for development of adequate repositories and support infrastructure in Madagascar to safeguard and display the country’s vertebrate fossil collections; doing so would ensure the preservation and appreciation of Madagascar’s rich natural heritage for future generations of scientists and Malagasy citizens alike.

  3. A simple technique for morphological measurement of cerebral arterial circle variations using public domain software (Osiris).

    Science.gov (United States)

    Ansari, Saeed; Dadmehr, Majid; Eftekhar, Behzad; McConnell, Douglas J; Ganji, Sarah; Azari, Hassan; Kamali-Ardakani, Shahab; Hoh, Brian L; Mocco, J

    2011-12-01

    This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

  4. Developing a personal computer-based data visualization system using public domain software

    Science.gov (United States)

    Chen, Philip C.

    1999-03-01

    The current research will investigate the possibility of developing a computing-visualization system using a public domain software system built on a personal computer. Visualization Toolkit (VTK) is available on UNIX and PC platforms. VTK uses C++ to build an executable. It has abundant programming classes/objects that are contained in the system library. Users can also develop their own classes/objects in addition to those existing in the class library. Users can develop applications with any of the C++, Tcl/Tk, and JAVA environments. The present research will show how a data visualization system can be developed with VTK running on a personal computer. The topics will include: execution efficiency; visual object quality; availability of the user interface design; and exploring the feasibility of the VTK-based World Wide Web data visualization system. The present research will feature a case study showing how to use VTK to visualize meteorological data with techniques including, iso-surface, volume rendering, vector display, and composite analysis. The study also shows how the VTK outline, axes, and two-dimensional annotation text and title are enhancing the data presentation. The present research will also demonstrate how VTK works in an internet environment while accessing an executable with a JAVA application programing in a webpage.

  5. Improved recovery from Gulf of Mexico reservoirs. Volume II (of 4): Task 5, modify publicly available simulators. Final report, February 14, 1995--October 13, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.

    1997-01-13

    The objective for this portion of the research involved the continuation of the modifications of the public domain simulators BOAST and MASTER. The modifications continued during this project are generic relative to both BOAST and MASTER. BOAST was the primary concern during the research however, because MASTER as well.

  6. The public understanding of nanotechnology in the food domain: the hidden role of views on science, technology, and nature.

    Science.gov (United States)

    Vandermoere, Frederic; Blanchemanche, Sandrine; Bieberstein, Andrea; Marette, Stephan; Roosen, Jutta

    2011-03-01

    In spite of great expectations about the potential of nanotechnology, this study shows that people are rather ambiguous and pessimistic about nanotechnology applications in the food domain. Our findings are drawn from a survey of public perceptions about nanotechnology food and nanotechnology food packaging (N = 752). Multinomial logistic regression analyses further reveal that knowledge about food risks and nanotechnology significantly influences people's views about nanotechnology food packaging. However, knowledge variables were unrelated to support for nanofood, suggesting that an increase in people's knowledge might not be sufficient to bridge the gap between the excitement some business leaders in the food sector have and the restraint of the public. Additionally, opposition to nanofood was not related to the use of heuristics but to trust in governmental agencies. Furthermore, the results indicate that public perceptions of nanoscience in the food domain significantly relate to views on science, technology, and nature.

  7. On the role of domain size and resolution in the simulations with the HIRHAM region climate model

    DEFF Research Database (Denmark)

    Larsen, Morten Andreas Dahl; Thejll, Peter; Christensen, Jens H.;

    2013-01-01

    We investigate the simulated temperature and precipitation of the HIRHAM regional climate model using systematic variations in domain size, resolution and detailed location in a total of eight simulations. HIRHAM was forced by ERA-Interim boundary data and the simulations focused on higher...... resolutions in the range of 5.5–12 km. HIRHAM outputs of seasonal precipitation and temperature were assessed by calculating distributed model errors against a higher resolution data set covering Denmark and a 0.25° resolution data set covering Europe. Furthermore the simulations were statistically tested......, the temperature errors were more highly significant than precipitation. In similarly sized domains, 12 of 16 combinations of variables, observation validation data and seasons showed better results for the highest resolution domain, but generally the most significant improvements were seen when varying the domain...

  8. Model-free methods of analyzing domain motions in proteins from simulation : A comparison of normal mode analysis and molecular dynamics simulation of lysozyme

    NARCIS (Netherlands)

    Hayward, S; Kitao, A; Berendsen, HJC

    1997-01-01

    Model-free methods are introduced to determine quantities pertaining to protein domain motions from normal mode analyses and molecular dynamics simulations, For the normal mode analysis, the methods are based on the assumption that in low frequency modes, domain motions can be well approximated by m

  9. A method for intermediate flooding and sinking simulation of a damaged floater in time domain

    OpenAIRE

    Ju-Sung Kim; Myung-Il Roh; Seung-Ho Ham

    2017-01-01

    When a floater such as a ship or an offshore structure is damaged in the sea, it is necessary to determine whether the floater will sink in water or not. If the floater will sink, the time to sink should be estimated to make an emergency plan. In addition, causes of the flooding should be investigated carefully. For this purpose, a method for performing intermediate flooding and sinking simulation of the damaged floater in time domain is proposed in this study. Overall process of the proposed...

  10. Do You Hear What I Hear? The Impact of a Hearing Voices Simulation on Affective Domain Attributes in Nursing Students.

    Science.gov (United States)

    Ward, Terry D

    2015-01-01

    Affective domain teaching and learning can facilitate the reduction of stigmatization of clients with mental illness in nursing students. Experiential learning activities such as simulation are regarded as an effective method for facilitating student learning in the affective domain. The project reported here measured the impact of a simulation experience, "Hearing Voices Which Are Distressing," on attitudes, values, and beliefs of accelerated baccalaureate students caring for clients with mental illness who experienced hearing voices.

  11. Ambrosia artemisiifolia L. pollen simulations over the Euro-CORDEX domain: model description and emission calibration

    Science.gov (United States)

    liu, li; Solmon, Fabien; Giorgi, Filippo; Vautard, Robert

    2014-05-01

    Ragweed Ambrosia artemisiifolia L. is a highly allergenic invasive plant. Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma (D'Amato et al., 2007). In the context of the ATOPICA EU program we are studying the links between climate, land use and ecological changes on the ragweed pollen emissions and concentrations. For this purpose, we implemented a pollen emission/transport module in the RegCM4 regional climate model in collaboration with ATOPICA partners. The Abdus Salam International Centre for Theoretical Physics (ICTP) regional climate model, i.e. RegCM4 was adapted to incorporate the pollen emissions from (ORCHIDEE French) Global Land Surface Model and a pollen tracer model for describing pollen convective transport, turbulent mixing, dry and wet deposition over extensive domains, using consistent assumption regarding the transport of multiple species (Fabien et al., 2008). We performed two families of recent-past simulations on the Euro-Cordex domain (simulation for future condition is been considering). Hindcast simulations (2000~2011) were driven by the ERA-Interim re-analyses and designed to best simulate past periods airborne pollens, which were calibrated with parts of observations and verified by comparison with the additional observations. Historical simulations (1985~2004) were driven by HadGEM CMPI5 and designed to serve as a baseline for comparison with future airborne concentrations as obtained from climate and land-use scenarios. To reduce the uncertainties on the ragweed pollen emission, an assimilation-like method (Rouǐl et al., 2009) was used to calibrate release based on airborne pollen observations. The observations were divided into two groups and used for calibration and validation separately. A wide range of possible calibration coefficients were tested for each calibration station, making the bias between observations and simulations within an admissible value then

  12. Optimization of neural networks for time-domain simulation of mooring lines

    DEFF Research Database (Denmark)

    Christiansen, Niels Hørbye; Voie, Per Erlend Torbergsen; Winther, Ole

    2016-01-01

    When using artificial neural networks in methods for dynamic analysis of slender structures, the computational effort associated with time-domain response simulation may be reduced drastically compared to classic solution strategies. This article demonstrates that the network structure...... of an artificial neural network, which has been trained to simulate forces in a mooring line of a floating offshore platform, can be optimized and reduced by different optimization procedures. The procedures both detect and prune the least salient network weights successively, and besides trimming the network......, they also can be used to rank the importance of the various network inputs. The dynamic response of slender marine structures often depends on several external load components, and by applying the optimization procedures to a trained artificial neural network, it is possible to classify the external force...

  13. A combined ADER-DG and PML approach for simulating wave propagation in unbounded domains

    KAUST Repository

    Amler, Thomas

    2012-09-19

    In this work, we present a numerical approach for simulating wave propagation in unbounded domains which combines discontinuous Galerkin methods with arbitrary high order time integration (ADER-DG) and a stabilized modification of perfectly matched layers (PML). Here, the ADER-DG method is applied to Bérenger’s formulation of PML. The instabilities caused by the original PML formulation are treated by a fractional step method that allows to monitor whether waves are damped in PML region. In grid cells where waves are amplified by the PML, the contribution of damping terms is neglected and auxiliary variables are reset. Results of 2D simulations in acoustic media with constant and discontinuous material parameters are presented to illustrate the performance of the method.

  14. Radiative transfer with scattering for domain-decomposed 3D MHD simulations of cool stellar atmospheres

    CERN Document Server

    Hayek, W; Carlsson, M; Trampedach, R; Collet, R; Gudiksen, B V; Hansteen, V H; Leenaarts, J

    2010-01-01

    We present the implementation of a radiative transfer solver with coherent scattering in the new BIFROST code for radiative magneto-hydrodynamical (MHD) simulations of stellar surface convection. The code is fully parallelized using MPI domain decomposition, which allows for large grid sizes and improved resolution of hydrodynamical structures. We apply the code to simulate the surface granulation in a solar-type star, ignoring magnetic fields, and investigate the importance of coherent scattering for the atmospheric structure. A scattering term is added to the radiative transfer equation, requiring an iterative computation of the radiation field. We use a short-characteristics-based Gauss-Seidel acceleration scheme to compute radiative flux divergences for the energy equation. The effects of coherent scattering are tested by comparing the temperature stratification of three 3D time-dependent hydrodynamical atmosphere models of a solar-type star: without scattering, with continuum scattering only, and with bo...

  15. First 3D radiative transfer with scattering for domain-decomposed MHD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hayek, W [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek ACT 2611 (Australia)], E-mail: hayek@mpa-garching.mpg.de

    2008-12-15

    This paper presents an implementation of the Gauss-Seidel solver for radiative transfer with scattering in the Oslo Stagger Code. It fully supports MPI parallelism through domain decomposition of the simulation box, enabling fast computation of radiative transfer at a high resolution. Continuum and line opacities are treated with either a multigroup method or opacity sampling. Line scattering probabilities are estimated using the van Regemorter approximation for de-excitation rates of electron collisions. A solar-type test simulation with continuum and line scattering exhibits a steeper temperature gradient due to decreased radiative heating above the optical surface when compared with the strict local thermodynamic equilibrium (LTE) case. The classical van Regemorter approximation may overestimate the importance of line scattering, implying that the true temperature structure will be in between the LTE case and the scattering case considered here. It is demonstrated that continuum scattering is unimportant in the case of the Sun.

  16. First 3D radiative transfer with scattering for domain-decomposed MHD simulations

    Science.gov (United States)

    Hayek, W.

    2008-12-01

    This paper presents an implementation of the Gauss Seidel solver for radiative transfer with scattering in the Oslo Stagger Code. It fully supports MPI parallelism through domain decomposition of the simulation box, enabling fast computation of radiative transfer at a high resolution. Continuum and line opacities are treated with either a multigroup method or opacity sampling. Line scattering probabilities are estimated using the van Regemorter approximation for de-excitation rates of electron collisions. A solar-type test simulation with continuum and line scattering exhibits a steeper temperature gradient due to decreased radiative heating above the optical surface when compared with the strict local thermodynamic equilibrium (LTE) case. The classical van Regemorter approximation may overestimate the importance of line scattering, implying that the true temperature structure will be in between the LTE case and the scattering case considered here. It is demonstrated that continuum scattering is unimportant in the case of the Sun.

  17. Radiation Hydrodynamics using Characteristics on Adaptive Decomposed Domains for Massively Parallel Star Formation Simulations

    CERN Document Server

    Buntemeyer, Lars; Peters, Thomas; Klassen, Mikhail; Pudritz, Ralph E

    2015-01-01

    We present an algorithm for solving the radiative transfer problem on massively parallel computers using adaptive mesh refinement and domain decomposition. The solver is based on the method of characteristics which requires an adaptive raytracer that integrates the equation of radiative transfer. The radiation field is split into local and global components which are handled separately to overcome the non-locality problem. The solver is implemented in the framework of the magneto-hydrodynamics code FLASH and is coupled by an operator splitting step. The goal is the study of radiation in the context of star formation simulations with a focus on early disc formation and evolution. This requires a proper treatment of radiation physics that covers both the optically thin as well as the optically thick regimes and the transition region in particular. We successfully show the accuracy and feasibility of our method in a series of standard radiative transfer problems and two 3D collapse simulations resembling the ear...

  18. Simulation of acoustic streaming by means of the finite-difference time-domain method

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco

    2012-01-01

    Numerical simulations of acoustic streaming generated by a standing wave in a narrow twodimensional cavity are presented. In this case, acoustic streaming arises from the viscous boundary layers set up at the surfaces of the walls. It is known that streaming vortices inside the boundary layer have...... directions of rotation that are opposite to those of the outer streaming vortices (Rayleigh streaming). The general objective of the work described in this paper has been to study the extent to which it is possible to simulate both the outer streaming vortices and the inner boundary layer vortices using...... the finite-difference time-domain method. To simplify the problem, thermal effects are not considered. The motivation of the described investigation has been the possibility of using the numerical method to study acoustic streaming, particularly under non-steady conditions. Results are discussed for channels...

  19. Full-wave finite-difference time-domain simulation of electromagnetic cloaking structures.

    Science.gov (United States)

    Zhao, Yan; Argyropoulos, Christos; Hao, Yang

    2008-04-28

    This paper proposes a radial dependent dispersive finite-difference time-domain method for the modeling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and taken into account in dispersive FDTD simulations. Numerical simulations demonstrate that under ideal conditions, objects placed inside the cloak are 'invisible' to external electromagnetic fields. However for the simplified cloak based on linear transformations, the back scattering has a similar level to the case of a PEC cylinder without any cloak, rendering the object still being 'visible'. It is also demonstrated numerically that the simplified cloak based on high-order transformations can indeed improve the cloaking performance.

  20. Combining numerical simulations with time-domain random walk for pathogen risk assessment in groundwater

    Science.gov (United States)

    Cvetkovic, V.; Molin, S.

    2012-02-01

    We present a methodology that combines numerical simulations of groundwater flow and advective transport in heterogeneous porous media with analytical retention models for computing the infection risk probability from pathogens in aquifers. The methodology is based on the analytical results presented in [1,2] for utilising the colloid filtration theory in a time-domain random walk framework. It is shown that in uniform flow, the results from the numerical simulations of advection yield comparable results as the analytical TDRW model for generating advection segments. It is shown that spatial variability of the attachment rate may be significant, however, it appears to affect risk in a different manner depending on if the flow is uniform or radially converging. In spite of the fact that numerous issues remain open regarding pathogen transport in aquifers on the field scale, the methodology presented here may be useful for screening purposes, and may also serve as a basis for future studies that would include greater complexity.

  1. Teaching undergraduate nursing students about environmental health: addressing public health issues through simulation.

    Science.gov (United States)

    Stanley, Mary Jo; Rojas, Deb

    2014-01-01

    Schools of nursing are challenged to find clinical placements in public health settings. Use of simulation can address situations unique to public health, with attention to specific concerns, such as environmental health. Environmental health is an integral part of public health nursing and is a standard of professional practice. Current simulations focus on acute care situations, offering limited scenarios with a public health perspective and excluding environmental health. This study's simulation scenario was created to enhance nursing students' understanding of public health concepts within an environmental health context. Outcomes from the simulation include the need for integration of environmental issues in public health teaching. Students stated that this scenario provided a broader understanding of the environmental influences that can affect the client's and family's health. This scenario fills a void in simulation content, while providing an interactive teaching and learning strategy to help students to apply knowledge to practice. Copyright 2014, SLACK Incorporated.

  2. Sensitivity of simulated regional Arctic climate to the choice of coupled model domain

    Directory of Open Access Journals (Sweden)

    Dmitry V. Sein

    2014-07-01

    Full Text Available The climate over the Arctic has undergone changes in recent decades. In order to evaluate the coupled response of the Arctic system to external and internal forcing, our study focuses on the estimation of regional climate variability and its dependence on large-scale atmospheric and regional ocean circulations. A global ocean–sea ice model with regionally high horizontal resolution is coupled to an atmospheric regional model and global terrestrial hydrology model. This way of coupling divides the global ocean model setup into two different domains: one coupled, where the ocean and the atmosphere are interacting, and one uncoupled, where the ocean model is driven by prescribed atmospheric forcing and runs in a so-called stand-alone mode. Therefore, selecting a specific area for the regional atmosphere implies that the ocean–atmosphere system can develop ‘freely’ in that area, whereas for the rest of the global ocean, the circulation is driven by prescribed atmospheric forcing without any feedbacks. Five different coupled setups are chosen for ensemble simulations. The choice of the coupled domains was done to estimate the influences of the Subtropical Atlantic, Eurasian and North Pacific regions on northern North Atlantic and Arctic climate. Our simulations show that the regional coupled ocean–atmosphere model is sensitive to the choice of the modelled area. The different model configurations reproduce differently both the mean climate and its variability. Only two out of five model setups were able to reproduce the Arctic climate as observed under recent climate conditions (ERA-40 Reanalysis. Evidence is found that the main source of uncertainty for Arctic climate variability and its predictability is the North Pacific. The prescription of North Pacific conditions in the regional model leads to significant correlation with observations, even if the whole North Atlantic is within the coupled model domain. However, the inclusion of the

  3. Finite domain simulations with adaptive boundaries: Accurate potentials and nonequilibrium movesets

    Science.gov (United States)

    Wagoner, Jason A.; Pande, Vijay S.

    2013-12-01

    We extend the theory of hybrid explicit/implicit solvent models to include an explicit domain that grows and shrinks in response to a solute's evolving configuration. The goal of this model is to provide an appropriate but not excessive amount of solvent detail, and the inclusion of an adjustable boundary provides a significant computational advantage for solutes that explore a range of configurations. In addition to the theoretical development, a successful implementation of this method requires (1) an efficient moveset that propagates the boundary as a new coordinate of the system, and (2) an accurate continuum solvent model with parameters that are transferable to an explicit domain of any size. We address these challenges and develop boundary updates using Monte Carlo moves biased by nonequilibrium paths. We obtain the desired level of accuracy using a "decoupling interface" that we have previously shown to remove boundary artifacts common to hybrid solvent models. Using an uncharged, coarse-grained solvent model, we then study the efficiency of nonequilibrium paths that a simulation takes by quantifying the dissipation. In the spirit of optimization, we study this quantity over a range of simulation parameters.

  4. Two distinct states of the HAMP domain from sensory rhodopsin transducer observed in unbiased molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Ivan Gushchin

    Full Text Available HAMP domain is a ubiquitous module of bacterial and archaeal two-component signaling systems. Considerable progress has been made recently in studies of its structure and conformational changes. However, the mechanism of signal transduction through the HAMP domain is not clear. It remains a question whether all the HAMPs have the same mechanism of action and what are the differences between the domains from different protein families. Here, we present the results of unbiased molecular dynamics simulations of the HAMP domain from the archaeal phototaxis signal transducer NpHtrII. Two distinct conformational states of the HAMP domain are observed, that differ in relative position of the helices AS1 and AS2. The longitudinal shift is roughly equal to a half of an α-helix turn, although sometimes it reaches one full turn. The states are closely related to the position of bulky hydrophobic aminoacids at the HAMP domain core. The observed features are in good agreement with recent experimental results and allow us to propose that the states detected in the simulations are the resting state and the signaling state of the NpHtrII HAMP domain. To the best of our knowledge, this is the first observation of the same HAMP domain in different conformations. The simulations also underline the difference between AMBER ff99-SB-ILDN and CHARMM22-CMAP forcefields, as the former favors the resting state and the latter favors the signaling state.

  5. Molecular dynamics simulations and in silico peptide ligand screening of the Elk-1 ETS domain

    Directory of Open Access Journals (Sweden)

    Hussain Abrar

    2011-11-01

    Full Text Available Abstract Background The Elk-1 transcription factor is a member of a group of proteins called ternary complex factors, which serve as a paradigm for gene regulation in response to extracellular signals. Its deregulation has been linked to multiple human diseases including the development of tumours. The work herein aims to inform the design of potential peptidomimetic compounds that can inhibit the formation of the Elk-1 dimer, which is key to Elk-1 stability. We have conducted molecular dynamics simulations of the Elk-1 ETS domain followed by virtual screening. Results We show the ETS dimerisation site undergoes conformational reorganisation at the α1β1 loop. Through exhaustive screening of di- and tri-peptide libraries against a collection of ETS domain conformations representing the dynamics of the loop, we identified a series of potential binders for the Elk-1 dimer interface. The di-peptides showed no particular preference toward the binding site; however, the tri-peptides made specific interactions with residues: Glu17, Gln18 and Arg49 that are pivotal to the dimer interface. Conclusions We have shown molecular dynamics simulations can be combined with virtual peptide screening to obtain an exhaustive docking protocol that incorporates dynamic fluctuations in a receptor. Based on our findings, we suggest experimental binding studies to be performed on the 12 SILE ranked tri-peptides as possible compounds for the design of inhibitors of Elk-1 dimerisation. It would also be reasonable to consider the score-ranked tri-peptides as a comparative test to establish whether peptide size is a determinant factor of binding to the ETS domain.

  6. Estimating and modelling bias of the hierarchical partitioning public-domain software: implications in environmental management and conservation.

    Directory of Open Access Journals (Sweden)

    Pedro P Olea

    Full Text Available BACKGROUND: Hierarchical partitioning (HP is an analytical method of multiple regression that identifies the most likely causal factors while alleviating multicollinearity problems. Its use is increasing in ecology and conservation by its usefulness for complementing multiple regression analysis. A public-domain software "hier.part package" has been developed for running HP in R software. Its authors highlight a "minor rounding error" for hierarchies constructed from >9 variables, however potential bias by using this module has not yet been examined. Knowing this bias is pivotal because, for example, the ranking obtained in HP is being used as a criterion for establishing priorities of conservation. METHODOLOGY/PRINCIPAL FINDINGS: Using numerical simulations and two real examples, we assessed the robustness of this HP module in relation to the order the variables have in the analysis. Results indicated a considerable effect of the variable order on the amount of independent variance explained by predictors for models with >9 explanatory variables. For these models the nominal ranking of importance of the predictors changed with variable order, i.e. predictors declared important by its contribution in explaining the response variable frequently changed to be either most or less important with other variable orders. The probability of changing position of a variable was best explained by the difference in independent explanatory power between that variable and the previous one in the nominal ranking of importance. The lesser is this difference, the more likely is the change of position. CONCLUSIONS/SIGNIFICANCE: HP should be applied with caution when more than 9 explanatory variables are used to know ranking of covariate importance. The explained variance is not a useful parameter to use in models with more than 9 independent variables. The inconsistency in the results obtained by HP should be considered in future studies as well as in those

  7. The mid-domain effect matters: simulation analyses of range-size distribution data from Mount Kinabalu, Borneo

    DEFF Research Database (Denmark)

    Grytnes, John-Arvid; Beaman, John H.; Romdal, Tom Skovlund;

    2008-01-01

    Aim In simulation exercises, mid-domain peaks in species richness arise as a result of the random placement of modelled species ranges within simulated geometric constraints. This has been called the mid-domain effect (MDE). Where close correspondence is found between such simulations and empirical...... within the domain (range-restricted MDE), and a model encompassing all species with the theoretical midpoint within the domain (midpoint-restricted MDE). These predictions are compared with observations from the elevational pattern of range-size distributions and species richness of vascular plants....... The distribution of range sizes gives different predictions between models including the MDE or not. Here, we produce predictions for species richness and distribution of range sizes from one model without the MDE and from two MDE models: a classical MDE model encompassing only species with their entire range...

  8. Monte Carlo simulation for thermal assisted reversal process of micro-magnetic torus ring with bistable closure domain structure

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Kenichi; Suzuki, Kenji; Yamaguchi, Katsuhiko, E-mail: yama@sss.fukushima-u.ac.jp

    2016-04-01

    Monte Carlo simulations were performed for temperature dependences of closure domain parameter for a magnetic micro-torus ring cluster under magnetic field on limited temperature regions. Simulation results show that magnetic field on tiny limited temperature region can reverse magnetic closure domain structures when the magnetic field is applied at a threshold temperature corresponding to intensity of applied magnetic field. This is one of thermally assisted switching phenomena through a self-organization process. The results show the way to find non-wasteful pairs between intensity of magnetic field and temperature region for reversing closure domain structure by temperature dependence of the fluctuation of closure domain parameter. Monte Carlo method for this simulation is very valuable to optimize the design of thermally assisted switching devices.

  9. Domain Rotation Simulation of the Magnetostriction Jump Effect of 〈110〉 Oriented TbDyFe Crystals

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chang-Sheng; MA Tian-Yu; PAN Xing-Wen; YAN Mi

    2012-01-01

    The compressive pre-stress induced magnetostriction jump effect of an [-110] oriented TbDyFe crystal is simulated by tracking the initial redistribution of magnetic domains and their volume fraction evolutions under external magnetic fields. Through searching for the free energy minima within both (-110) and (110) planes, it is found that the axial compressive pre-stress not only switches magnetizations of the 35° domains toward the perpendicular plane, but also switches magnetizations of the 90° domains approaching the [110] direction. When increasing the stress magnitude, the volume fraction for 35° domains decreases and the one for the [110] domain increases rapidly. However, the volume fraction for the four 90° domains within the perpendicular plane first increases to a maximum under a certain stress magnitude and further decreases. The stress-induced anisotropy thereafter changes the volume fraction evolutions during the magnetization process, which explains well the magnetostriction jump effect.%The compressive pre-stress induced magnetostriction jump effect of an [(-1) 10] oriented TbDyFe crystal is simulated by tracking the initial redistribution of magnetic domains and their volune fraction evolutions under external magnetic fields.Through searching for the free energy minima within both ((-1) 10) and (110) planes,it is found that the axial compressive pre-stress not only switches magnetizations of the 35° domains toward the perpendicular plane,but also switches magnetizations of the 90° domains approaching the [110] direction.When increasing the stress magnitude,the volume fraction for 35° domains decreases and the one for the [110] domain increases rapidly.However,the volume fraction for the four 90° domains within the perpendicular plane first increases to a maximum under a certain stress magnitude and further decreases.The stress-induced anisotropy thereafter changes the volume fraction evolutions during the magnetization process,which explains

  10. 版权法上的公共领域研究%On public domain in copyright law

    Institute of Scientific and Technical Information of China (English)

    黄汇

    2009-01-01

    Public domain is a core rule of copyright law, under which various creative materials are available for an author to use without charge or liability for infringement, hence ensuring the effective implementation of copyright law.Public domain is characterized by openness, public ownership, irrevocability and formality. Based on the premise that the author's work will not be interfered, public domain ultimately aims at the enlargement of its own universe and prosperity of the culture of human society. Its introduction into copyright law satisfies both historical and logical demands. Without its acknowledgement,copyright cannot be justified. In that sense, public domain and copyright can be deemed as twins. Public domain is not only an existing institution, but also an ideological tendency or a methodology. It has evaluative and inspective values towards copyright. It is an important precondition of copy-rights, and what is more, an important measure for controlling the expansion and realizing the purpose of copyright.%公共领域是版权法的核心,它是保证作者有效运用各种创作素材从而使版权的其余部分得以良好运转的工具.公共领域具有开放性、有主性、不可撤销性和程序性等特征,它以保证作者的创作为前提,却最终以自身的不断扩大和人类社会的文化繁衍为依归.公共领域在版权法上的生成既是历史的,更是逻辑的.没有公共领域的被承认,也就没有版权的正当性可言,因此公共领域和版权实际上一同诞生.公共领域不仅是一种制度存在物,它更是一种思想倾向和方法论,公共领域对版权具有评价和检视功能,它既是版权运行的重要前提,又是控制版权扩张和实现版权目的的重要手段.

  11. Implementation Strategies for Large-Scale Transport Simulations Using Time Domain Particle Tracking

    Science.gov (United States)

    Painter, S.; Cvetkovic, V.; Mancillas, J.; Selroos, J.

    2008-12-01

    Time domain particle tracking is an emerging alternative to the conventional random walk particle tracking algorithm. With time domain particle tracking, particles are moved from node to node on one-dimensional pathways defined by streamlines of the groundwater flow field or by discrete subsurface features. The time to complete each deterministic segment is sampled from residence time distributions that include the effects of advection, longitudinal dispersion, a variety of kinetically controlled retention (sorption) processes, linear transformation, and temporal changes in groundwater velocities and sorption parameters. The simulation results in a set of arrival times at a monitoring location that can be post-processed with a kernel method to construct mass discharge (breakthrough) versus time. Implementation strategies differ for discrete flow (fractured media) systems and continuous porous media systems. The implementation strategy also depends on the scale at which hydraulic property heterogeneity is represented in the supporting flow model. For flow models that explicitly represent discrete features (e.g., discrete fracture networks), the sampling of residence times along segments is conceptually straightforward. For continuous porous media, such sampling needs to be related to the Lagrangian velocity field. Analytical or semi-analytical methods may be used to approximate the Lagrangian segment velocity distributions in aquifers with low-to-moderate variability, thereby capturing transport effects of subgrid velocity variability. If variability in hydraulic properties is large, however, Lagrangian velocity distributions are difficult to characterize and numerical simulations are required; in particular, numerical simulations are likely to be required for estimating the velocity integral scale as a basis for advective segment distributions. Aquifers with evolving heterogeneity scales present additional challenges. Large-scale simulations of radionuclide

  12. Time Domain Simulation of Sound Waves Using Smoothed Particle Hydrodynamics Algorithm with Artificial Viscosity

    Directory of Open Access Journals (Sweden)

    Xu Li

    2015-06-01

    Full Text Available Smoothed particle hydrodynamics (SPH, as a Lagrangian, meshfree method, is supposed to be useful in solving acoustic problems, such as combustion noise, bubble acoustics, etc., and has been gradually used in sound wave computation. However, unphysical oscillations in the sound wave simulation cannot be ignored. In this paper, an artificial viscosity term is added into the standard SPH algorithm used for solving linearized acoustic wave equations. SPH algorithms with or without artificial viscosity are both built to compute sound propagation and interference in the time domain. Then, the effects of the smoothing kernel function, particle spacing and Courant number on the SPH algorithms of sound waves are discussed. After comparing SPH simulation results with theoretical solutions, it is shown that the result of the SPH algorithm with the artificial viscosity term added attains good agreement with the theoretical solution by effectively reducing unphysical oscillations. In addition, suitable computational parameters of SPH algorithms are proposed through analyzing the sound pressure errors for simulating sound waves.

  13. Measurements and time-domain simulations of multiphonics in the trombone.

    Science.gov (United States)

    Velut, Lionel; Vergez, Christophe; Gilbert, Joël

    2016-10-01

    Multiphonic sounds of brass instruments are studied in this article. They are produced by playing a note on a brass instrument while simultaneously singing another note in the mouthpiece. This results in a peculiar sound, heard as a chord or a cluster of more than two notes in most cases. This effect is used in different artistic contexts. Measurements of the mouth pressure, the pressure inside the mouthpiece, and the radiated sound are recorded while a trombone player performs a multiphonic, first by playing an F3 and singing a C4, then playing an F3 and singing a note with a decreasing pitch. Results highlight the quasi-periodic nature of the multiphonic sound and the appearance of combination tones due to intermodulation between the played and the sung sounds. To assess the ability of a given brass instrument physical model to reproduce the measured phenomenon, time-domain simulations of multiphonics are carried out. A trombone model consisting in an exciter and a resonator nonlinearly coupled is forced while self-oscillating to reproduce simultaneous singing and playing. Comparison between simulated and measured signals is discussed. Spectral content of the simulated pressure match very well with the measured one, at the cost of a high forcing pressure.

  14. Domain Wall Fermion Simulations with the Exact One-Flavor Algorithm

    CERN Document Server

    Murphy, D J

    2016-01-01

    As algorithmic developments have driven down the cost of simulating degenerate light quark pairs the relative cost of simulating single quark flavors with the Rational Hybrid Monte Carlo (RHMC) algorithm has become more expensive. TWQCD has proposed an exact one-flavor algorithm (EOFA) that allows for HMC simulations of a single quark flavor without taking a square root of the fermion determinant. We have independently implemented EOFA in the Columbia Physics System (CPS) and BAGEL Fermion Sparse-Matrix Library (BFM) for Shamir and M\\"{o}bius domain wall fermions, and begun to optimize and test our implementation against RHMC. In this talk we discuss the derivation of the EOFA action, our tests of its equivalence to RHMC, and the current state of our implementation and optimization. We find, after introducing a novel preconditioning technique for the EOFA Dirac operator, that EOFA is a factor of 2.4 times faster than RHMC per molecular dynamics trajectory for the strange quark determinant on an $N_{f} = 2+1$ ...

  15. Critical size dependence of domain formation observed in coarse-grained simulations of bilayers composed of ternary lipid mixtures

    Science.gov (United States)

    Pantelopulos, George A.; Nagai, Tetsuro; Bandara, Asanga; Panahi, Afra; Straub, John E.

    2017-09-01

    Model cellular membranes are known to form micro- and macroscale lipid domains dependent on molecular composition. The formation of macroscopic lipid domains by lipid mixtures has been the subject of many simulation investigations. We present a critical study of system size impact on lipid domain phase separation into liquid-ordered and liquid-disordered macroscale domains in ternary lipid mixtures. In the popular di-C16:0 PC:di-C18:2 PC:cholesterol at 35:35:30 ratio mixture, we find systems with a minimum of 1480 lipids to be necessary for the formation of macroscopic phase separated domains and systems of 10 000 lipids to achieve structurally converged conformations similar to the thermodynamic limit. To understand these results and predict the behavior of any mixture forming two phases, we develop and investigate an analytical Flory-Huggins model which is recursively validated using simulation and experimental data. We find that micro- and macroscale domains can coexist in ternary mixtures. Additionally, we analyze the distributions of specific lipid-lipid interactions in each phase, characterizing domain structures proposed based on past experimental studies. These findings offer guidance in selecting appropriate system sizes for the study of phase separations and provide new insights into the nature of domain structure for a popular ternary lipid mixture.

  16. Mechanochemical coupling in the myosin motor domain. I. Insights from equilibrium active-site simulations.

    Directory of Open Access Journals (Sweden)

    Haibo Yu

    2007-02-01

    Full Text Available Although the major structural transitions in molecular motors are often argued to couple to the binding of Adenosine triphosphate (ATP, the recovery stroke in the conventional myosin has been shown to be dependent on the hydrolysis of ATP. To obtain a clearer mechanistic picture for such "mechanochemical coupling" in myosin, equilibrium active-site simulations with explicit solvent have been carried out to probe the behavior of the motor domain as functions of the nucleotide chemical state and conformation of the converter/relay helix. In conjunction with previous studies of ATP hydrolysis with different active-site conformations and normal mode analysis of structural flexibility, the results help establish an energetics-based framework for understanding the mechanochemical coupling. It is proposed that the activation of hydrolysis does not require the rotation of the lever arm per se, but the two processes are tightly coordinated because both strongly couple to the open/close transition of the active site. The underlying picture involves shifts in the dominant population of different structural motifs as a consequence of changes elsewhere in the motor domain. The contribution of this work and the accompanying paper [] is to propose the actual mechanism behind these "population shifts" and residues that play important roles in the process. It is suggested that structural flexibilities at both the small and large scales inherent to the motor domain make it possible to implement tight couplings between different structural motifs while maintaining small free-energy drops for processes that occur in the detached states, which is likely a feature shared among many molecular motors. The significantly different flexibility of the active site in different X-ray structures with variable level arm orientations supports the notation that external force sensed by the lever arm may transmit into the active site and influence the chemical steps (nucleotide

  17. Engineering phase shifter domains for multiple QPM using simulated annealing algorithm

    Science.gov (United States)

    Siva, Chellappa; Sunder Meetei, Toijam; Shiva, Prabhakar; Narayanan, Balaji; Arvind, Ganesh; Boomadevi, Shanmugam; Pandiyan, Krishnamoorthy

    2017-10-01

    We have utilized the general algorithm of simulated annealing (SA) to engineer the phase shifter domains in a quasi-phase-matching (QPM) device to generate multiple frequency conversion. SA is an algorithm generally used to find the global maxima or minima in a given random function. Here, we have utilized this algorithm to generate multiple QPM second harmonic generation (SHG) by distributing phase shifters suitably. In general, phase shifters are distributed in a QPM device with some specific profile along the length to generate multiple QPM SHG. Using the SA algorithm, the location of these phase shifters can be easily identified to have the desired multiple QPM with higher conversion efficiency. The methodology to generate the desired multiple QPM SHG using the SA algorithm has been discussed in detail.

  18. Power-feedwater temperature operating domain for Sbwr applying Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar M, L. A.; Quezada G, S.; Espinosa M, E. G.; Vazquez R, A.; Varela H, J. R.; Cazares R, R. I.; Espinosa P, G., E-mail: sequega@gmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2014-10-15

    In this work the analyses of the feedwater temperature effects on reactor power in a simplified boiling water reactor (Sbwr) applying a methodology based on Monte Carlo simulation is presented. The Monte Carlo methodology was applied systematically to establish operating domain, due that the Sbwr are not yet in operation, the analysis of the nuclear and thermal-hydraulic processes must rely on numerical modeling, with the purpose of developing or confirming the design basis and qualifying the existing or new computer codes to enable reliable analyses. The results show that the reactor power is inversely proportional to the temperature of the feedwater, reactor power changes at 8% when the feed water temperature changes in 8%. (Author)

  19. Parallel two-level domain decomposition based Jacobi-Davidson algorithms for pyramidal quantum dot simulation

    Science.gov (United States)

    Zhao, Tao; Hwang, Feng-Nan; Cai, Xiao-Chuan

    2016-07-01

    We consider a quintic polynomial eigenvalue problem arising from the finite volume discretization of a quantum dot simulation problem. The problem is solved by the Jacobi-Davidson (JD) algorithm. Our focus is on how to achieve the quadratic convergence of JD in a way that is not only efficient but also scalable when the number of processor cores is large. For this purpose, we develop a projected two-level Schwarz preconditioned JD algorithm that exploits multilevel domain decomposition techniques. The pyramidal quantum dot calculation is carefully studied to illustrate the efficiency of the proposed method. Numerical experiments confirm that the proposed method has a good scalability for problems with hundreds of millions of unknowns on a parallel computer with more than 10,000 processor cores.

  20. The Design of Cognitive Social Simulation Framework using Statistical Methodology in the Domain of Academic Science

    Directory of Open Access Journals (Sweden)

    R. Sivakumar

    2013-05-01

    Full Text Available Modeling the behavior of the cognitive architecture in the context of social simulation using statistical methodologies is currently a growing research area. Normally, a cognitive architecture for an intelligent agent involves artificial computational process which exemplifies theories of cognition in computer algorithms under the consideration of state space. More specifically, for such cognitive system with large state space the problem like large tables and data sparsity are faced. Hence in this paper, we have proposed a method using a value iterative approach based on Q-learning algorithm, with function approximation technique to handle the cognitive systems with large state space. From the experimental results in the application domain of academic science it has been verified that the proposed approach has better performance compared to its existing approaches.

  1. Dissipative Particle Dynamics Simulations of Domain Growth and Phase Separation in Binary Immiscible Fluids

    Institute of Scientific and Technical Information of China (English)

    Ying Zhao; Hong Liu; Zhong-yuan Lu; Chia-chung Sun

    2008-01-01

    It was investigated that the domain growth processes of spinodal decomposition with different quenching depth in two and three dimensional binary immiscible fluids by using parallel dissipative particle dynamics simulations. In two dimensions, the dynamic scaling exponent 1/2 for coalescence and 2/3 for inertial regimes in the shallow quench and strong finite size effects in the cases of deep quenching were obtained. In three dimensions, it was used that the diffusive regime with exponent n=1/3 in the shallow quench and the inertial hydrodynamic regime with n=2/3 for different quenches. The viscous effects are not clearly reflected, showing n=l/2 in both shallow and deep quenches in this time period, due to the soft nature of interaction potential adopted in dissipative particle dynamics.

  2. Time Domain Simulation of a One Line Failure for a DP-assisted Mooring System

    Institute of Scientific and Technical Information of China (English)

    Jianxun Zhu; Liping Sun; Shengnan Liu; Jichuang Kang

    2014-01-01

    This paper focuses on the research of a semi-submersible platform equipped with a DP-assisted mooring system. Based on the working principles of the DP-assisted mooring system and the model of the platform motion, a time domain simulation program is applied to analyze the impact, in the case of one line failure, on the platform motion, power consumption of the thrusters and the tension of the mooring lines. The results show that, under the 10-year wind dominant, a one line failure will have little impact on the tension of the mooring lines. When the failure line is windward, the power consumption will increase greatly with a weakened position of accuracy. However when the failure line is leeward, the power consumption will be reduced with a partly strengthened position of accuracy.

  3. Simulating the Activation of Voltage Sensing Domain for a Voltage-Gated Sodium Channel Using Polarizable Force Field.

    Science.gov (United States)

    Sun, Rui-Ning; Gong, Haipeng

    2017-03-02

    Voltage-gated sodium (NaV) channels play vital roles in the signal transduction of excitable cells. Upon activation of a NaV channel, the change of transmembrane voltage triggers conformational change of the voltage sensing domain, which then elicits opening of the pore domain and thus allows an influx of Na(+) ions. Description of this process with atomistic details is in urgent demand. In this work, we simulated the partial activation process of the voltage sensing domain of a prokaryotic NaV channel using a polarizable force field. We not only observed the conformational change of the voltage sensing domain from resting to preactive state, but also rigorously estimated the free energy profile along the identified reaction pathway. Comparison with the control simulation using an additive force field indicates that voltage-gating thermodynamics of NaV channels may be inaccurately described without considering the electrostatic polarization effect.

  4. The ICTP Regional System Model (RESM) to simulate the monsoon in the South Asia CORDEX domain

    Science.gov (United States)

    Di Sante, Fabio; Coppola, Erika; Farneti, Riccardo; Giorgi, Filippo

    2016-04-01

    South Asian climate is characterized mainly by the wet and dry dipole that divides the annual cycle in two seasons: the monsoon season and the dry season. The life and the economy of those regions is very much influenced by the climate variability and the monsoon variability therefore is crucial to understand the physical mechanism associated with them. The spatial and temporal representation of the monsoons over the South Asian region is one of the main challenge of global and regional climate models principally because they fail to represent the SST (sea surface temperature) induced rainfall when forced with observed SST resulting in a poor representation of the monsoon cycle (Fu et al. 2002). The coupling with the ocean is essential to be able to simulate the correct air-sea interaction; the results are in general much improved and the monsoon patterns and the time representation (like the onset for example) are closer to the observations (Fu et al. 2002; Fu et al. 2007; Ratnam et Al. 2008; Seo et Al. 2009). Here we present a Regional Earth System Model (RESM) composed by a regional climate model RegCM4 (Giorgi et al, 2012) coupled with the regional oceanic model MITgcm (Marshall et al, 1997) and two hydrological model: ChyM (Cetemps Hydrological Model, Coppola et al, 2007) and HD model (Max-Planck's HD model; Hagemann and Dümenil, 1998). We simulate the Southern Asian Climate taking into account the whole hydrological cycle. Wind stress, water fluxes and heat fluxes are exchanged from the atmosphere to the ocean, SST are exchanged from ocean to the atmosphere and in order to conserve mass, the river discharge is calculated from the Hydrological model and sent to the ocean. The main goal of this work is to evaluate the impacts of local air-sea interaction in the simulation of the interannual variability, over the Indian CORDEX (Giorgi et al, 2009) domain through regionally ocean-atmosphere-river coupled and uncoupled simulations, with a focus on monsoon season

  5. ACSL (Advanced Continuous Simulation Language) Simulation of a Third Order Butterworth Filter Using Implementations Derived From Both Z and S Domain Representations.

    Science.gov (United States)

    1984-02-01

    proerm witi three ina added to it for geeration of the mueamdn of tho the em tem doadom Wee. CCI’ % ud he dowo Z domsan veruloms, CWVUN sad CIILL The m...THIRD ORDER BUTTERWORTH FILTER USING IMPLEMENTATIONS DERIVED FROM BOTH Z AND S DOMAIN REPRESENTATIONS get Edvard E. L. Mitchell Mitchell and Gauthier...S. TYPE OF REPORT & PERIOD COVERED ACSL SIMULATION OF A THIRD ORDER BUTTERWORTH FILTER USING IMPLEMENTATIONS DERIVED FROM BOTH Z AND S DOMAIN

  6. A Novel High Order Time Domain Vector Finite Element Method for the Simulation of Electromagnetic Devices

    Energy Technology Data Exchange (ETDEWEB)

    Rieben, Robert N. [Univ. of California, Davis, CA (United States)

    2004-01-01

    The goal of this dissertation is two-fold. The first part concerns the development of a numerical method for solving Maxwell's equations on unstructured hexahedral grids that employs both high order spatial and high order temporal discretizations. The second part involves the use of this method as a computational tool to perform high fidelity simulations of various electromagnetic devices such as optical transmission lines and photonic crystal structures to yield a level of accuracy that has previously been computationally cost prohibitive. This work is based on the initial research of Daniel White who developed a provably stable, charge and energy conserving method for solving Maxwell's equations in the time domain that is second order accurate in both space and time. The research presented here has involved the generalization of this procedure to higher order methods. High order methods are capable of yielding far more accurate numerical results for certain problems when compared to corresponding h-refined first order methods , and often times at a significant reduction in total computational cost. The first half of this dissertation presents the method as well as the necessary mathematics required for its derivation. The second half addresses the implementation of the method in a parallel computational environment, its validation using benchmark problems, and finally its use in large scale numerical simulations of electromagnetic transmission devices.

  7. A Novel High Order Time Domain Vector Finite Element Method for the Simulation of Electromagnetic Devices

    Energy Technology Data Exchange (ETDEWEB)

    Rieben, R N

    2004-07-20

    The goal of this dissertation is twofold. The first part concerns the development of a numerical method for solving Maxwell's equations on unstructured hexahedral grids that employs both high order spatial and high order temporal discretizations. The second part involves the use of this method as a computational tool to perform high fidelity simulations of various electromagnetic devices such as optical transmission lines and photonic crystal structures to yield a level of accuracy that has previously been computationally cost prohibitive. This work is based on the initial research of Daniel White who developed a provably stable, charge and energy conserving method for solving Maxwell's equations in the time domain that is second order accurate in both space and time. The research presented here has involved the generalization of this procedure to higher order methods. High order methods are capable of yielding far more accurate numerical results for certain problems when compared to corresponding h-refined first order methods , and often times at a significant reduction in total computational cost. The first half of this dissertation presents the method as well as the necessary mathematics required for its derivation. The second half addresses the implementation of the method in a parallel computational environment, its validation using benchmark problems, and finally its use in large scale numerical simulations of electromagnetic transmission devices.

  8. Superlattice of stress domains in nanometer-size semiconductor devices predicted from atomistic simulations

    Science.gov (United States)

    Bachlechner, Martina E.; Ebbsjö, Ingvar; Kalia, Rajiv K.; Kodiyalam, Sanjay; Madhukar, Anupam; Nakano, Aiichiro; Omeltchenko, Andrey; Walsh, Phillip; Vashishta, Priya

    2001-03-01

    Semiconductor industry association estimates pixel sizes in next generation devices to be on the order of 70 nm by the year of 2008. Although recent measurements of local strain distributions2 and strain relaxation in nano wires have reached 100-nm spatial resolution, experimental tools for determining stresses for sub 100 nm, feature sizes are still to be developed4. On the other hand, recent developments in efficient simulation algorithms on state-of-the-art parallel computers5 enable us to gain valuable information on interface structure and atomic level stresses in nanopixels of < 100 nm size. Here, we present results for a 27.5-million atom molecular-dynamics simulations of a 70 nm x 70 nm crystalline silicon nanopixel covered with amorphous silicon nitride and placed on a 140 nm x 140 nm crystalline silicon substrate. The stresses parallel to the silicon/silicon nitride interface exhibit a hexagonal superlattice of stress domains with a lattice constant of 12.8 (±1.8) nm. From our analysis of the 70 nm x 70 nm pixel and on comparing with a smaller 25 nm x 25 nm nanopixel, we conclude that for square pixels the superlattice constant is independent of the pixel size and is entirely determined by the mismatch between silicon and silicon nitride. Such stress inhomogeneity with values of up to ±2 GPa will have a significant impact on the performance of semiconductor devices with sub 100 nm features.

  9. Modal locking between vocal fold and vocal tract oscillations: Simulations in time domain

    CERN Document Server

    Aalto, Atte; Malinen, Jarmo; Aalto, Daniel; Vainio, Martti

    2015-01-01

    It is well known that during voiced speech, the human vocal folds interact with the vocal tract acoustics. The resulting source-filter coupling has been observed using mathematical and physical models as well as in in vivo phonation. We propose a computational time-domain model of the full speech apparatus that, in particular, contains a feedback mechanism from the vocal tract acoustics to the vocal fold oscillations. It is based on numerical solution of ordinary and partial differential equations defined on vocal tract geometries that have been obtained by Magnetic Resonance Imaging. The model is used to simulate rising and falling pitch glides of [a, i] in the fundamental frequency (f_0) interval [180 Hz, 360 Hz]. The interval contains the first formant F1 of [i] as well as the subformants F1/4 and F1/3 of [a]. The simulations reveal a locking pattern of the f_0-trajectory at F1 of [i] in falling and rising glides. The subformants of [a] produce perturbations in the waveforms of glottal signals but no locki...

  10. Radiation hydrodynamics using characteristics on adaptive decomposed domains for massively parallel star formation simulations

    Science.gov (United States)

    Buntemeyer, Lars; Banerjee, Robi; Peters, Thomas; Klassen, Mikhail; Pudritz, Ralph E.

    2016-02-01

    We present an algorithm for solving the radiative transfer problem on massively parallel computers using adaptive mesh refinement and domain decomposition. The solver is based on the method of characteristics which requires an adaptive raytracer that integrates the equation of radiative transfer. The radiation field is split into local and global components which are handled separately to overcome the non-locality problem. The solver is implemented in the framework of the magneto-hydrodynamics code FLASH and is coupled by an operator splitting step. The goal is the study of radiation in the context of star formation simulations with a focus on early disc formation and evolution. This requires a proper treatment of radiation physics that covers both the optically thin as well as the optically thick regimes and the transition region in particular. We successfully show the accuracy and feasibility of our method in a series of standard radiative transfer problems and two 3D collapse simulations resembling the early stages of protostar and disc formation.

  11. Domain of the Gods: Do traditional beliefs hinder public acceptance of the human role in climate change?

    Science.gov (United States)

    Donner, S.

    2008-12-01

    Public acceptance of new scientific discoveries like natural selection, plate tectonics, or the human role in climate change naturally lags behind the pace of the discoveries. In the case of climate change, unease or outright rejection of the scientific evidence for the role of human activity in climate change has been a hindrance to mitigation and adaptation efforts. This skepticism is normally attributed to everything from the quality of science education, to disinformation campaigns by representatives of the coal and gas industry, to individual resistance to behavioral change, to the nature of the modern information culture. This skepticism of scientific evidence for climate change, though often inspired by politics, economics and the particular dynamics of climate change, may actually be rooted in ancient beliefs that the climate is beyond the influence of humans. In this presentation, I will outline how the notion that humans control or influence the weather runs contrary to thousands of years of belief in a separation between the earth - the domain of man - and sky - the domain of the gods. Evidence from religious history, traditional villages in the Pacific (Fjij and Kiribati) and from public discourse in North America all indicates that the millennia-old belief in an earth-sky separation hinders people's acceptance that human activity is affecting the climate. The human role in climate change therefore represents a substantial paradigm shift, similar to the role of natural selection in human evolution. These deep roots of climate change skepticism must be factored into public climate change education efforts.

  12. The Maritime Public Domain - concept and implementation in diferent national legal systems.

    Directory of Open Access Journals (Sweden)

    Marco Gameiro Antunes

    2014-05-01

    The paper will also describe how the ownership (public vs. private of coastal and estuarine margins is seen in some legal systems, considering the contribution of MPD to the protection of estuarine water and to the biodiversity resources.

  13. 32 CFR 705.35 - Armed Forces participation in events in the public domain.

    Science.gov (United States)

    2010-07-01

    ... Department of Defense to ensure compliance with public law, to assure equitable distribution of resources to... primary attraction. (4) Armed Forces participation is authorized in a fund-raising event only when the...

  14. A Poverty Simulation to Inform Public Health Practice

    Science.gov (United States)

    Strasser, Sheryl; Smith, Megan O.; Pendrick Denney, Danielle; Jackson, Matt C.; Buckmaster, Pam

    2013-01-01

    Background: Poverty is a pervasive condition linked to a myriad of health conditions and severe health outcomes. Public health professionals are at the forefront of addressing poverty-related issues and require education that enhances their understanding and cultural competence. Purpose: The purpose of this research was to evaluate the impacts of…

  15. A Poverty Simulation to Inform Public Health Practice

    Science.gov (United States)

    Strasser, Sheryl; Smith, Megan O.; Pendrick Denney, Danielle; Jackson, Matt C.; Buckmaster, Pam

    2013-01-01

    Background: Poverty is a pervasive condition linked to a myriad of health conditions and severe health outcomes. Public health professionals are at the forefront of addressing poverty-related issues and require education that enhances their understanding and cultural competence. Purpose: The purpose of this research was to evaluate the impacts of…

  16. Characterization of molecular recognition of STAT3 SH2 domain inhibitors through molecular simulation.

    Science.gov (United States)

    Park, In-Hee; Li, Chenglong

    2011-01-01

    Signal transducer and activator of transcription 3 (STAT3) is an anti-cancer target protein due to its over-activation in tumor cells. The Tyr705-phosphorylated (pTyr) STAT3 binds to the pTyr-recognition site of its Src Homology 2 (SH2) domain of another STAT3 monomer to form a homo-dimer, which then causes cellular anti-apoptosis, proliferation, and tumor invasion. Recently, many STAT3 SH2 dimerization inhibitors have been discovered via both computational and experimental methods. To systematically assess their binding affinities and specificities, for eight representative inhibitors, we utilized molecular docking, molecular dynamics simulation, and ensuing energetic analysis to compare their binding characteristics. The inhibitors' binding free energies were calculated via MMPB(GB)SA, and the STAT3 SH2 binding "hot spots" were evaluated through binding energy decomposition and hydrogen bond (H-bond) distribution analysis. Several conclusions can be drawn: (1) the overall enthalpy-entropy compensation paradigm is preserved for the STAT3 SH2/ligand binding thermodynamics; (2) at one end of the binding spectrum, two compounds bind to SH2 due to their minimum entropic penalties that result from their relative rigidities and increased dynamics of SH2 upon their binding; at the other end of the binding spectrum, one compound shows a typical weak binder behavior due to its loose binding in the SH2's strongest enthalpy-contributing binding subsite; (3) hydrogen bonding seems a strong indicator to evaluate the SH2/ligand binding potency, which echoes a finding that CH/π non-classical H-bond is responsible for some pTyr peptides binding to their corresponding SH2 domains; (4) STAT3 SH2 domain possesses three binding "hot spots": pTyr705-binding pocket with polar residues and contributing the largest binding enthalpy (two-thirds); Leu706 subsite which is the most dynamic and hardest to target; a hydrophobic side pocket which is unique to STAT3 and very targetable, which

  17. Production of radioactive phantoms using a standard inkjet printer and the public domain multi-printing code GENIA.

    Science.gov (United States)

    Scafè, R; Auer, P; Bennati, P; La Porta, L; Pisacane, F; Cinti, M N; Pellegrini, R; De Vincentis, G; Conte, G; Pani, R

    2011-10-01

    The public domain code GENIA, based on multi-printing method for producing surface sources with appropriate radioactivity, is described. The conventional technique, running on standard inkjet printer with radio-marked ink filling, is improved by repeating elementary printing commands in the same band. Well outlined sources with adjustable radioactivity can be obtained without refilling. The intrinsic limitation of printable radioactivity, depending on the value available at nozzles at printing time, was overcome. In addition the method permits the accurate calibration of the amount of activity released onto the paper.

  18. The effect of C-terminal helix on the stability of FF domain studied by molecular dynamics simulation.

    Science.gov (United States)

    Zhao, Liling; Cao, Zanxia; Wang, Jihua

    2012-01-01

    To investigate the effect of C-terminal helix on the stability of the FF domain, we studied the native domain FF3-71 from human HYPA/FBP11 and the truncated version FF3-60 with C-terminal helix being deleted by molecular dynamics simulations with GROMACS package and GROMOS 43A1 force field. The results indicated that the structures of truncated version FF3-60 were evident different from those of native partner FF3-71. Compared with FF3-71, the FF3-60 lost some native contacts and exhibited some similar structural characters to those of intermediate state. The C-terminal helix played a major role in stabilizing the FF3-71 domain. To a certain degree, the FF domain had a tendency to form an intermediate state without the C-terminal helix. In our knowledge, this was the first study to examine the role of C-terminal helix of FF domain in detail by molecular dynamics simulations, which was useful to understand the three-state folding mechanism of the small FF domain.

  19. Bifunctional homodimeric triokinase/FMN cyclase: contribution of protein domains to the activities of the human enzyme and molecular dynamics simulation of domain movements.

    Science.gov (United States)

    Rodrigues, Joaquim Rui; Couto, Ana; Cabezas, Alicia; Pinto, Rosa María; Ribeiro, João Meireles; Canales, José; Costas, María Jesús; Cameselle, José Carlos

    2014-04-11

    Mammalian triokinase, which phosphorylates exogenous dihydroxyacetone and fructose-derived glyceraldehyde, is neither molecularly identified nor firmly associated to an encoding gene. Human FMN cyclase, which splits FAD and other ribonucleoside diphosphate-X compounds to ribonucleoside monophosphate and cyclic X-phosphodiester, is identical to a DAK-encoded dihydroxyacetone kinase. This bifunctional protein was identified as triokinase. It was modeled as a homodimer of two-domain (K and L) subunits. Active centers lie between K1 and L2 or K2 and L1: dihydroxyacetone binds K and ATP binds L in different subunits too distant (≈ 14 Å) for phosphoryl transfer. FAD docked to the ATP site with ribityl 4'-OH in a possible near-attack conformation for cyclase activity. Reciprocal inhibition between kinase and cyclase reactants confirmed substrate site locations. The differential roles of protein domains were supported by their individual expression: K was inactive, and L displayed cyclase but not kinase activity. The importance of domain mobility for the kinase activity of dimeric triokinase was highlighted by molecular dynamics simulations: ATP approached dihydroxyacetone at distances below 5 Å in near-attack conformation. Based upon structure, docking, and molecular dynamics simulations, relevant residues were mutated to alanine, and kcat and Km were assayed whenever kinase and/or cyclase activity was conserved. The results supported the roles of Thr(112) (hydrogen bonding of ATP adenine to K in the closed active center), His(221) (covalent anchoring of dihydroxyacetone to K), Asp(401) and Asp(403) (metal coordination to L), and Asp(556) (hydrogen bonding of ATP or FAD ribose to L domain). Interestingly, the His(221) point mutant acted specifically as a cyclase without kinase activity.

  20. Citing National Publications as a metrics for localization of Science: A Study on Scholar Journals of Social Science Domain in Iran from 2002 to 2010

    Directory of Open Access Journals (Sweden)

    Mohammad Tavakolizadeh-Ravari

    2015-02-01

    Conclusion: Based on this metric, the tendency toward the use of national publications in the social science domain is constant despite the number of scientific productions is growing in Iran. This means that the Iranian social science domain not only doesn’t tend to the science localization but its use of foreign science is growing in the span of time as well.

  1. The influence of domain knowledge on strategy use during simulation-based inquiry learning.

    NARCIS (Netherlands)

    Lazonder, Adrianus W.; Wilhelm, P.; Hagemans, M.G.

    2008-01-01

    This study investigated how students' knowledge of a particular domain influences the type of investigative strategy they utilize in an inquiry learning task within that domain. Students with high domain knowledge were assumed to employ a theory-driven strategy, whereas less knowledgeable students

  2. Changement climatique et domaines skiables: simulation en Savoie et Haute-Savoie à l’horizon 2015

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Loubier

    2007-03-01

    Full Text Available Les domaines skiables et le changement climatique posent des questions importantes et nouvelles pour les espaces montagnards. Dans les hautes vallées où ces domaines sont souvent le moteur principal du développement local, on peut s'interroger sur la pérennité du modèle économique de l'or blanc à moyen terme quand les modèles de simulation du climat tablent sur une élévation de la température moyenne comprise entre 1,5° et 5° en 2100. Nous avons tenté de simuler les effets du changement climatique à l'horizon 2015, sur les domaines skiables de Savoie et Haute Savoie.

  3. Low-Frequency Loudspeaker-Room Simulation Using Finite Differences in the Time Domain-Part 1: Analysis

    DEFF Research Database (Denmark)

    Celestinos, Adrian; Nielsen, Sofus Birkedal

    2008-01-01

    Small- and medium-size rectangular rooms have a strong influence on the low-frequency performance of loudspeakers. A simulation program based on the finite-difference time-domain (FDTD) method is introduced to analyze the sound field produced by loudspeakers in rectangular rooms at low frequencies...

  4. Low-Frequency Loudspeaker-Room Simulation Using Finite Differences in the Time Domain-Part 1: Analysis

    DEFF Research Database (Denmark)

    Celestinos, Adrian; Nielsen, Sofus Birkedal

    2008-01-01

    Small- and medium-size rectangular rooms have a strong influence on the low-frequency performance of loudspeakers. A simulation program based on the finite-difference time-domain (FDTD) method is introduced to analyze the sound field produced by loudspeakers in rectangular rooms at low frequencies...

  5. (Un)folding mechanisms of the FBP28 WW domain in explicit solvent revealed by multiple rare event simulation methods

    NARCIS (Netherlands)

    Juraszek, J.; Bolhuis, P.G.

    2010-01-01

    We report a numerical study of the (un)folding routes of the truncated FBP28 WW domain at ambient conditions using a combination of four advanced rare event molecular simulation techniques. We explore the free energy landscape of the native state, the unfolded state, and possible intermediates, with

  6. Time-domain Simulations of the Acoustic Streaming Produced by a Propagating Wave Radiated by a Circular Piston

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco

    2013-01-01

    Results of numerical simulations of the sound field produced by a circular piston in a rigid baffled are presented. The aim was to calculate the acoustic streaming and the flow of mass generated by the sound field. For this purpose, the classical finite-difference time-domain method was implemented...

  7. A method for intermediate flooding and sinking simulation of a damaged floater in time domain

    Directory of Open Access Journals (Sweden)

    Ju-Sung Kim

    2017-01-01

    Full Text Available When a floater such as a ship or an offshore structure is damaged in the sea, it is necessary to determine whether the floater will sink in water or not. If the floater will sink, the time to sink should be estimated to make an emergency plan. In addition, causes of the flooding should be investigated carefully. For this purpose, a method for performing intermediate flooding and sinking simulation of the damaged floater in time domain is proposed in this study. Overall process of the proposed method consists of several steps. In the first step, data of the damaged floater such as hull form and compartments are prepared. In the second step, physical characteristics of the floater such as the increased weight considering incoming water, the center of gravity, the changed buoyancy, and the center of buoyancy are calculated at every time step. In the third step, the quasi-static equilibrium position of the floater is calculated. The second and third steps are repeated until the floater reaches to sink or to be in equilibrium. As a result, the final condition of the floater can be determined. To check the feasibility of the proposed method, it is applied to a simple box problem. Finally, it is applied to intermediate flooding simulation of a barge-type damaged floater. Two cases having damaged holes of different locations are selected. As a result, it was confirmed that the floater can be in equilibrium or sink according to the damaged position. The time to be in equilibrium or the time to sink was estimated.

  8. Time-Domain Simulation for Coupled Motions of Three Barges Moored Side-by-Side in Floatover Operation

    Institute of Scientific and Technical Information of China (English)

    许鑫; 杨建民; 李欣; 徐亮瑜

    2015-01-01

    Simulating the coupled motions of multiple bodies in the time domain is a complex problem because of the strong hydrodynamic interactions and coupled effect of various mechanical connectors. In this study, we investigate the hydrodynamic responses of three barges moored side-by-side in a floatover operation in the frequency and time domains. In the frequency domain, the damping lid method is adopted to improve the overestimated hydrodynamic coefficients calculated from conventional potential flow theory. A time-domain computing program based on potential flow theory and impulse theory is compiled for analyses that consider multibody hydrodynamic interactions and mechanical effects from lines and fenders. Correspondingly, an experiment is carried out for comparison with the numerical results. All statistics, time series, and power density spectra from decay and irregular wave tests are in a fairly good agreement.

  9. Accuracy of three-dimensional seismic ground response analysis in time domain using nonlinear numerical simulations

    Science.gov (United States)

    Liang, Fayun; Chen, Haibing; Huang, Maosong

    2017-07-01

    To provide appropriate uses of nonlinear ground response analysis for engineering practice, a three-dimensional soil column with a distributed mass system and a time domain numerical analysis were implemented on the OpenSees simulation platform. The standard mesh of a three-dimensional soil column was suggested to be satisfied with the specified maximum frequency. The layered soil column was divided into multiple sub-soils with a different viscous damping matrix according to the shear velocities as the soil properties were significantly different. It was necessary to use a combination of other one-dimensional or three-dimensional nonlinear seismic ground analysis programs to confirm the applicability of nonlinear seismic ground motion response analysis procedures in soft soil or for strong earthquakes. The accuracy of the three-dimensional soil column finite element method was verified by dynamic centrifuge model testing under different peak accelerations of the earthquake. As a result, nonlinear seismic ground motion response analysis procedures were improved in this study. The accuracy and efficiency of the three-dimensional seismic ground response analysis can be adapted to the requirements of engineering practice.

  10. Surge Response of a Compliant Offshore Structure by Time Domain Simulation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A single-degree-of-freedom equation of motion was used for modeling a compliant offshore structure exposed to viscous hydrodynamic loads. The equation of motion contains nonlinearities in the forms of both Duffing stiffness and Morison drag force with current. The water particle velocity and acceleration for calculating the Morison inertia and drag forces are modeled as Gaussian processes based on a Pierson-Moskowitz (P-M) elevation spectrum. The single-degree-of-freedom equation of motion containing different ocean current values are then numerically integrated via a fourth-order Runge-Kutta scheme. Time trajectories of the surge response displacements of the offshore structure and the response probability density curves are obtained. Furthermore, the ocean current influences on the response central moments up to the fourth order are studied. A literature review reveals that this is the first treatment of such a pair of nonlinearities in time domain. The simulation results are analyzed, and some conclusions valuable for engineering design are pointed out.

  11. Features of a time domain simulation tool for rigid riser design

    Energy Technology Data Exchange (ETDEWEB)

    Morooka, Celso K.; Brandt, Dustin M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo; Matt, Cyntia G.C.; Franciss, Ricardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2008-07-01

    This paper present a number of numerical implementations designed for the analysis of rigid riser's static and dynamic behavior that includes the effects of vortex induced vibrations (VIV) and marine hydrodynamic loads in time domain. Features include the ability to consider pipe with a free-span utilizing a soil/riser interaction model. An implementation of a numerical coupling scheme to couple the vertical riser and platform dynamics was developed to allow prediction of the sub sea Blow-Out Preventer (BOP) re-entry into a sub sea petroleum well when drilling different phases of deep and ultra-deep wells. The developments contains support for the consideration of the Self Standing Hybrid Riser (SSHR) configuration which has been shown to be a promising riser configuration in deep and ultra-deep waters. A graphical interface was also created to better grasp the results and aid in the modeling, processing and to help analyze the numerical simulations, contributing to enhance agility and quality of the riser design and analysis processes. (author)

  12. Changing Perceptions of Homesteading as a Policy of Public Domain Disposal

    Science.gov (United States)

    Edwards, Richard

    2009-01-01

    The inspiring story of homesteaders claiming free land and realizing their dreams became one of the enduring narratives of American history. But scholars who have studied homesteading have often been much more ambivalent, even harshly negative, about how successful it was in practice. While the public often views our history differently from…

  13. Investigation of Alien Wavelength Quality in Live Multi-Domain, Multi-Vendor Link Using Advanced Simulation Tool

    DEFF Research Database (Denmark)

    Petersen, Martin Nordal; Nuijts, Roeland; Bjorn, Lars Lange

    2014-01-01

    This article presents an advanced optical model for simulation of alien wavelengths in multi-domain and multi-vendor dense wavelength-division multiplexing networks. The model aids optical network planners with a better understanding of the non-linear effects present in dense wavelength-division ......This article presents an advanced optical model for simulation of alien wavelengths in multi-domain and multi-vendor dense wavelength-division multiplexing networks. The model aids optical network planners with a better understanding of the non-linear effects present in dense wavelength......-division multiplexing systems and better utilization of alien wavelengths in future applications. The limiting physical effects for alien wavelengths are investigated in relation to power levels, channel spacing, and other factors. The simulation results are verified through experimental setup in live multi...

  14. 41 CFR 102-75.100 - When an agency holds land withdrawn or reserved from the public domain and determines that it no...

    Science.gov (United States)

    2010-07-01

    ... land withdrawn or reserved from the public domain and determines that it no longer needs this land, what must it do? 102-75.100 Section 102-75.100 Public Contracts and Property Management Federal... it no longer needs this land, what must it do? An agency holding unneeded land withdrawn or...

  15. Multi-domain product modelling: from requirements to cad and simulation tools.

    OpenAIRE

    FREY, Estelle; Ostrosi, Egon; Roucoules, Lionel; Gomes, Samuel

    2009-01-01

    Today, in a very competitive industrial context, different companies have difficulties to respect delays in design and manufacturing of multi-domain product. These difficulties are most of time due to the non respect of requirements defined at the beginning of the project development, during the Function Performance Specifications phase. Furthermore, an important problem during multi-domain products design and development process is the communication between experts of different domains. ...

  16. Hamiltonian replica exchange combined with elastic network analysis to enhance global domain motions in atomistic molecular dynamics simulations.

    Science.gov (United States)

    Ostermeir, Katja; Zacharias, Martin

    2014-12-01

    Coarse-grained elastic network models (ENM) of proteins offer a low-resolution representation of protein dynamics and directions of global mobility. A Hamiltonian-replica exchange molecular dynamics (H-REMD) approach has been developed that combines information extracted from an ENM analysis with atomistic explicit solvent MD simulations. Based on a set of centers representing rigid segments (centroids) of a protein, a distance-dependent biasing potential is constructed by means of an ENM analysis to promote and guide centroid/domain rearrangements. The biasing potentials are added with different magnitude to the force field description of the MD simulation along the replicas with one reference replica under the control of the original force field. The magnitude and the form of the biasing potentials are adapted during the simulation based on the average sampled conformation to reach a near constant biasing in each replica after equilibration. This allows for canonical sampling of conformational states in each replica. The application of the methodology to a two-domain segment of the glycoprotein 130 and to the protein cyanovirin-N indicates significantly enhanced global domain motions and improved conformational sampling compared with conventional MD simulations.

  17. Micromagnetic simulation of thickness variation of Neel cap in hybrid Bloch-Neel domain wall

    Energy Technology Data Exchange (ETDEWEB)

    Lu Mai [Key Lab. of Opto-Electronic Technology and Intelligent Control, Lanzhou Jiaotong University, Ministry of Education, P.O. Box 73, 118 West Anning Road, Lanzhou 730070, Gansu (China) and Department of Signals and Systems, Chalmers University of Technology, SE-412 96, Gothenburg (Sweden)]. E-mail: m.lu@mail.edu.cn; Leonard, Paul J. [Department of Electronic and Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2005-08-01

    The hybrid Bloch-Neel domain wall in iron film has been investigated using three-dimensional micromagnetic calculations. Magnetization distributions in the film plane and cross-section are presented. In the film plane the rotation of magnetization in the 180 deg domain wall takes two different patterns from the bottom layer to the top layer. In cross-section the C-shaped magnetization distribution with hybrid Bloch-Neel domain wall has been found. The thickness of the top Neel cap changes from its largest value as the C-shaped magnetization distribution appears, and becomes thinner as the C-shaped magnetization distribution gradually moves and grows up. The thickness variation of the bottom Neel cap changes in a similar way, but with a reversal pattern. The results in this paper will enrich our knowledge of magnetic domain and domain wall patterns in magnetic materials.

  18. Asthma in Urban Children: Epidemiology, Environmental Risk Factors, and the Public Health Domain.

    Science.gov (United States)

    Milligan, Ki Lee; Matsui, Elizabeth; Sharma, Hemant

    2016-04-01

    Asthma is the most commonly reported chronic condition of childhood in developed countries, with 6.5 million children affected in the USA. A disparate burden of childhood asthma is seen among socioeconomically disadvantaged youth, often concentrated in urban areas with high poverty rates. Host factors that predispose a child to asthma include atopy, male gender, parental history of asthma, and also race, ethnicity, and genetic and epigenetic susceptibilities. Environmental factors, such as improved hygiene, ambient air pollution, and early life exposures to microbes and aeroallergens, also influence the development of asthma. With greater than 90% of time spent indoors, home exposures (such as cockroach, rodent, and indoor air pollution) are highly relevant for urban asthma. Morbidity reduction may require focused public health initiatives for environmental intervention in high priority risk groups and the addition of immune modulatory agents in children with poorly controlled disease.

  19. High-fidelity simulation in the nonmedical domain: practices and potential transferable competencies for the medical field

    Directory of Open Access Journals (Sweden)

    Carron PN

    2011-05-01

    Full Text Available Pierre-Nicolas Carron, Lionel Trueb, Bertrand YersinEmergency Service, University Hospital Center, Lausanne, SwitzerlandAbstract: Simulation is a promising pedagogical tool in the area of medical education. High-fidelity simulators can reproduce realistic environments or clinical situations. This allows for the practice of teamwork and communication skills, thereby enhancing reflective reasoning and experiential learning. Use of high-fidelity simulators is not limited to the medical and aeronautical fields, but has developed in a large number of nonmedical organizations as well. The techniques and pedagogical tools which have evolved through the use of nonmedical simulations serve not only as teaching examples but also as avenues which can help further the evolution of the concept of high-fidelity simulation in the field of medicine. This paper presents examples of high-fidelity simulations in the military, maritime, and aeronautical fields. We compare the implementation of high-fidelity simulation in the medical and nonmedical domains, and discuss the possibilities and limitations of simulators in medicine, based on recent nonmedical applications.Keywords: high-fidelity simulation, crew resource management, experiential learning

  20. Lattice-gas simulations of Domain Growth, Saturation and Self-Assembly in Immiscible Fluids and Microemulsions

    CERN Document Server

    Emerton, A N; Boghosian, B M; Emerton, Andrew N.; Coveney, Peter V.; Boghosian, Bruce M.

    1996-01-01

    We investigate the dynamical behavior of both binary fluid and ternary microemulsion systems in two dimensions using a recently introduced hydrodynamic lattice-gas model of microemulsions. We find that the presence of amphiphile in our simulations reduces the usual oil-water interfacial tension in accord with experiment and consequently affects the non-equilibrium growth of oil and water domains. As the density of surfactant is increased we observe a crossover from the usual two-dimensional binary fluid scaling laws to a growth that is {\\it slow}, and we find that this slow growth can be characterized by a logarithmic time scale. With sufficient surfactant in the system we observe that the domains cease to grow beyond a certain point and we find that this final characteristic domain size is inversely proportional to the interfacial surfactant concentration in the system.

  1. Development of mooring-anchor program in public domain for coupling with floater program for FOWTs (Floating Offshore Wind Turbines)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, MooHyun [American Bureau of Shipping (ABS), Houston, TX (United States)

    2014-08-01

    This report presents the development of offshore anchor data sets which are intended to be used to develop a database that allows preliminary selection and sizing of anchors for the conceptual design of floating offshore wind turbines (FOWTs). The study is part of a project entitled “Development of Mooring-Anchor Program in Public Domain for Coupling with Floater Program for FOWTs (Floating Offshore Wind Turbines)”, under the direction of Dr. Moo-Hyun Kim at the Texas A&M University and with the sponsorship from the US Department of Energy (Contract No. DE-EE0005479, CFDA # 81.087 for DE-FOA-0000415, Topic Area 1.3: Subsurface Mooring and Anchoring Dynamics Models).

  2. Open window: when easily identifiable genomes and traits are in the public domain.

    Directory of Open Access Journals (Sweden)

    Misha Angrist

    Full Text Available "One can't be of an enquiring and experimental nature, and still be very sensible."--Charles Fort. As the costs of personal genetic testing "self-quantification" fall, publicly accessible databases housing people's genotypic and phenotypic information are gradually increasing in number and scope. The latest entrant is openSNP, which allows participants to upload their personal genetic/genomic and self-reported phenotypic data. I believe the emergence of such open repositories of human biological data is a natural reflection of inquisitive and digitally literate people's desires to make genomic and phenotypic information more easily available to a community beyond the research establishment. Such unfettered databases hold the promise of contributing mightily to science, science education and medicine. That said, in an age of increasingly widespread governmental and corporate surveillance, we would do well to be mindful that genomic DNA is uniquely identifying. Participants in open biological databases are engaged in a real-time experiment whose outcome is unknown.

  3. Evolution of Industry Knowledge in the Public Domain: Prior Art Searching for Software Patents

    Directory of Open Access Journals (Sweden)

    Jinseok Park

    2005-03-01

    Full Text Available Searching prior art is a key part of the patent application and examination processes. A comprehensive prior art search gives the inventor ideas as to how he can improve or circumvent existing technology by providing up to date knowledge on the state of the art. It also enables the patent applicant to minimise the likelihood of an objection from the patent office. This article explores the characteristics of prior art associated with software patents, dealing with difficulties in searching prior art due to the lack of resources, and considers public contribution to the formation of prior art databases. It addresses the evolution of electronic prior art in line with technological development, and discusses laws and practices in the EPO, USPTO, and the JPO in relation to the validity of prior art resources on the Internet. This article also investigates the main features of searching sources and tools in the three patent offices as well as non-patent literature databases. Based on the analysis of various searching databases, it provides some strategies of efficient prior art searching that should be considered for software-related inventions.

  4. Simulation of Domain Formation in p-Si/SiGe Quantum Cascade Structures

    Science.gov (United States)

    Ikonic, Z.; Harrison, P.; Kelsall, R. W.

    Domain formation in p-doped Si/SiGe quantum cascades is considered using a carrier scattering transport framework. The hole flow along the cascade is described via scattering between quantized states belonging to neighbouring periods, caused by phonons, alloy disorder, and carrier-carrier interactions. The generation of either periodic or of nonperiodic domains is studied in uniformly or modulationally doped cascades, and criteria for their appearance are found. The domains in modulationally doped cascades have a relatively smaller effect on the energy structure than in uniformly doped ones.

  5. An object-oriented designed finite-difference time-domain simulator for electromagnetic analysis and design in MRI.

    Science.gov (United States)

    Wei, Q; Crozier, S; Xia, L; Liu, F

    2004-01-01

    This paper presents a finite-difference time-domain (FDTD) simulator for electromagnetic analysis and design applications in magnetic resonance imaging (MRI). It is intended to be a complete FDTD model of an MRI system including all RF and low frequency field generating units and electrical models of the patient. The framework has been constructed with the assistance of object-oriented concepts. The detailed design procedure is described and the numerical method has been verified against analytical solutions for simple cases and also applied to real field calculations. The simulated results demonstrated that the proposed FDTD scheme can be used to analyze large-scale computational electromagnetic problems in MRI engineering.

  6. Advances in time-domain electromagnetic simulation capabilities through the use of overset grids and massively parallel computing

    Science.gov (United States)

    Blake, Douglas Clifton

    A new methodology is presented for conducting numerical simulations of electromagnetic scattering and wave-propagation phenomena on massively parallel computing platforms. A process is constructed which is rooted in the Finite-Volume Time-Domain (FVTD) technique to create a simulation capability that is both versatile and practical. In terms of versatility, the method is platform independent, is easily modifiable, and is capable of solving a large number of problems with no alterations. In terms of practicality, the method is sophisticated enough to solve problems of engineering significance and is not limited to mere academic exercises. In order to achieve this capability, techniques are integrated from several scientific disciplines including computational fluid dynamics, computational electromagnetics, and parallel computing. The end result is the first FVTD solver capable of utilizing the highly flexible overset-gridding process in a distributed-memory computing environment. In the process of creating this capability, work is accomplished to conduct the first study designed to quantify the effects of domain-decomposition dimensionality on the parallel performance of hyperbolic partial differential equations solvers; to develop a new method of partitioning a computational domain comprised of overset grids; and to provide the first detailed assessment of the applicability of overset grids to the field of computational electromagnetics. Using these new methods and capabilities, results from a large number of wave propagation and scattering simulations are presented. The overset-grid FVTD algorithm is demonstrated to produce results of comparable accuracy to single-grid simulations while simultaneously shortening the grid-generation process and increasing the flexibility and utility of the FVTD technique. Furthermore, the new domain-decomposition approaches developed for overset grids are shown to be capable of producing partitions that are better load balanced and

  7. Comparison of UWB Impulse, FMCW, and Noise Radar for Through-wall Bioradiolocation with Finite Difference Time Domain Simulations

    OpenAIRE

    2009-01-01

    Using the ¯nite di®erence time domain (FDTD) method we have conducted bio- radiolocation simulation to assess the e®ectiveness of remote monitoring of the cardiorespiratory parameters of human behind opaque obstacles by radar. The radiation source types under study are ultra-wide band (UWB) impulse, frequency modulated continuous wave (FMCW), and ran- dom electromagnetic noises. The impulse radar demands the most sophisticated hardware source modulation but minimal in software ...

  8. Monitoring Urban Tree Cover Using Object-Based Image Analysis and Public Domain Remotely Sensed Data

    Directory of Open Access Journals (Sweden)

    Meghan Halabisky

    2011-10-01

    Full Text Available Urban forest ecosystems provide a range of social and ecological services, but due to the heterogeneity of these canopies their spatial extent is difficult to quantify and monitor. Traditional per-pixel classification methods have been used to map urban canopies, however, such techniques are not generally appropriate for assessing these highly variable landscapes. Landsat imagery has historically been used for per-pixel driven land use/land cover (LULC classifications, but the spatial resolution limits our ability to map small urban features. In such cases, hyperspatial resolution imagery such as aerial or satellite imagery with a resolution of 1 meter or below is preferred. Object-based image analysis (OBIA allows for use of additional variables such as texture, shape, context, and other cognitive information provided by the image analyst to segment and classify image features, and thus, improve classifications. As part of this research we created LULC classifications for a pilot study area in Seattle, WA, USA, using OBIA techniques and freely available public aerial photography. We analyzed the differences in accuracies which can be achieved with OBIA using multispectral and true-color imagery. We also compared our results to a satellite based OBIA LULC and discussed the implications of per-pixel driven vs. OBIA-driven field sampling campaigns. We demonstrated that the OBIA approach can generate good and repeatable LULC classifications suitable for tree cover assessment in urban areas. Another important finding is that spectral content appeared to be more important than spatial detail of hyperspatial data when it comes to an OBIA-driven LULC.

  9. Time Domain Simulation of Transient Responses of Very Large Floating Structures Under Unsteady External Loads

    Institute of Scientific and Technical Information of China (English)

    QIU Liu-chao; LIU Hua

    2005-01-01

    A time domain finite element method (FEM) for the analysis of transient elastic response of a very large floating structure (VLFS) subjected to arbitrary time-dependent external loads is presented. This method is developed directly in time domain and the hydrodynamic problem is formulated based on linear, inviscid and slightly compressible fluid theory and the structural response is analyzed on the thin plate assumption. The time domain finite element procedure herein is validated by comparing numerical results with available experimental data. Finally, the transient elastic response of a pontoon-type VLFS under the landing of an airplane is computed by the proposed time domain FEM. The time histories of the applied force and the position and velocity of an airplane during landing are modeled with data from a Boeing 747-400 jumbo jet.

  10. Phase field simulation of domain switching dynamics in multiaxial lead zirconate titanate thin films

    Science.gov (United States)

    Britson, Jason

    The defining characteristic of ferroelectric materials is their ability to be switched between energetically equivalent polarization states. This behavior has led to an interest in ferroelectrics for a wide range of bulk and thin film applications such as mechanical actuators and ferroelectric random access memory devices. Ferroelectric switching depends on domain wall motion, however, and is critically influenced by the existence of defects such as dislocations and preexisting domains. Domain wall motion in thin film applications can be controlled by individual local defects due to the reduced length scale of the system. This dissertation describes the impact of preexisting ferroelastic domains and misfits dislocations in coherent (001)-oriented Pb(Zr0.2,Ti0.8)O3 (PZT) thin films on the switching response and domain structure. A phase field model based on the Landau-Ginzburg-Devonshire theory that accounts for the electrostatic and mechanical interactions is used to describe domain structures in ferroelectric PZT thin films. To solve the governing equations a semi-implicit Fourier-Spectral scheme is developed that accommodates boundary conditions appropriate to the thin film geometry. Errors are reduced in the solutions at the film edges through extensions to the model developed to correct the Fourier transform around stationary discontinuities at the thin film edges. This correction is shown to result in increased accuracy of the phase field model needed to appropriately describe dynamic switching responses in the thin film. Investigation of switching around preexisting ferroelastic domains showed these defects are strong obstacles to switching in PZT thin films. Directly above the ferroelastic domain the magnitude of the required nucleation bias underneath a tip-like electrode was found to be elevated compared to the required bias far from the domain. Locally both the piezoelectric and dielectric responses of the thin film were found to be suppressed, which is

  11. High-speed extended-term time-domain simulation for online cascading analysis of power system

    Science.gov (United States)

    Fu, Chuan

    A high-speed extended-term (HSET) time domain simulator (TDS), intended to become a part of an energy management system (EMS), has been newly developed for use in online extended-term dynamic cascading analysis of power systems. HSET-TDS includes the following attributes for providing situational awareness of high-consequence events: (i) online analysis, including n-1 and n-k events, (ii) ability to simulate both fast and slow dynamics for 1-3 hours in advance, (iii) inclusion of rigorous protection-system modeling, (iv) intelligence for corrective action ID, storage, and fast retrieval, and (v) high-speed execution. Very fast on-line computational capability is the most desired attribute of this simulator. Based on the process of solving algebraic differential equations describing the dynamics of power system, HSET-TDS seeks to develop computational efficiency at each of the following hierarchical levels, (i) hardware, (ii) strategies, (iii) integration methods, (iv) nonlinear solvers, and (v) linear solver libraries. This thesis first describes the Hammer-Hollingsworth 4 (HH4) implicit integration method. Like the trapezoidal rule, HH4 is symmetrically A-Stable but it possesses greater high-order precision (h4 ) than the trapezoidal rule. Such precision enables larger integration steps and therefore improves simulation efficiency for variable step size implementations. This thesis provides the underlying theory on which we advocate use of HH4 over other numerical integration methods for power system time-domain simulation. Second, motivated by the need to perform high speed extended-term time domain simulation (HSET-TDS) for on-line purposes, this thesis presents principles for designing numerical solvers of differential algebraic systems associated with power system time-domain simulation, including DAE construction strategies (Direct Solution Method), integration methods(HH4), nonlinear solvers(Very Dishonest Newton), and linear solvers(SuperLU). We have

  12. Proposing New Methods to Enhance the Low-Resolution Simulated GPR Responses in the Frequency and Wavelet Domains

    Directory of Open Access Journals (Sweden)

    Reza Ahmadi

    2014-12-01

    Full Text Available To date, a number of numerical methods, including the popular Finite-Difference Time Domain (FDTD technique, have been proposed to simulate Ground-Penetrating Radar (GPR responses. Despite having a number of advantages, the finite-difference method also has pitfalls such as being very time consuming in simulating the most common case of media with high dielectric permittivity, causing the forward modelling process to be very long lasting, even with modern high-speed computers. In the present study the well-known hyperbolic pattern response of horizontal cylinders, usually found in GPR B-Scan images, is used as a basic model to examine the possibility of reducing the forward modelling execution time. In general, the simulated GPR traces of common reflected objects are time shifted, as with the Normal Moveout (NMO traces encountered in seismic reflection responses. This suggests the application of Fourier transform to the GPR traces, employing the time-shifting property of the transformation to interpolate the traces between the adjusted traces in the frequency domain (FD. Therefore, in the present study two post-processing algorithms have been adopted to increase the speed of forward modelling while maintaining the required precision. The first approach is based on linear interpolation in the Fourier domain, resulting in increasing lateral trace-to-trace interval of appropriate sampling frequency of the signal, preventing any aliasing. In the second approach, a super-resolution algorithm based on 2D-wavelet transform is developed to increase both vertical and horizontal resolution of the GPR B-Scan images through preserving scale and shape of hidden hyperbola features. Through comparing outputs from both methods with the corresponding actual high-resolution forward response, it is shown that both approaches can perform satisfactorily, although the wavelet-based approach outperforms the frequency-domain approach noticeably, both in amplitude and

  13. Public repository with Monte Carlo simulations for high-energy particle collision experiments

    CERN Document Server

    Chekanov, S V

    2016-01-01

    Planning high-energy collision experiments for the next few decades requires extensive Monte Carlo simulations in order to accomplish physics goals of these experiments. Such simulations are essential for understanding fundamental physics processes, as well as for setting up the detector parameters that help establish R&D projects required over the next few decades. This paper describes a public repository with Monte Carlo event samples before and after detector-response simulation. The goal of this repository is to facilitate the accomplishment of many goals in planning a next generation of particle experiments.

  14. Multi-ensemble regional simulation of Indian monsoon during contrasting rainfall years: role of convective schemes and nested domain

    Science.gov (United States)

    Devanand, Anjana; Ghosh, Subimal; Paul, Supantha; Karmakar, Subhankar; Niyogi, Dev

    2017-08-01

    Regional simulations of the seasonal Indian summer monsoon rainfall (ISMR) require an understanding of the model sensitivities to physics and resolution, and its effect on the model uncertainties. It is also important to quantify the added value in the simulated sub-regional precipitation characteristics by a regional climate model (RCM), when compared to coarse resolution rainfall products. This study presents regional model simulations of ISMR at seasonal scale using the Weather Research and Forecasting (WRF) model with the synoptic scale forcing from ERA-interim reanalysis, for three contrasting monsoon seasons, 1994 (excess), 2002 (deficit) and 2010 (normal). Impact of four cumulus schemes, viz., Kain-Fritsch (KF), Betts-Janjić-Miller, Grell 3D and modified Kain-Fritsch (KFm), and two micro physical parameterization schemes, viz., WRF Single Moment Class 5 scheme and Lin et al. scheme (LIN), with eight different possible combinations are analyzed. The impact of spectral nudging on model sensitivity is also studied. In WRF simulations using spectral nudging, improvement in model rainfall appears to be consistent in regions with topographic variability such as Central Northeast and Konkan Western Ghat sub-regions. However the results are also dependent on choice of cumulus scheme used, with KF and KFm providing relatively good performance and the eight member ensemble mean showing better results for these sub-regions. There is no consistent improvement noted in Northeast and Peninsular Indian monsoon regions. Results indicate that the regional simulations using nested domains can provide some improvements on ISMR simulations. Spectral nudging is found to improve upon the model simulations in terms of reducing the intra ensemble spread and hence the uncertainty in the model simulated precipitation. The results provide important insights regarding the need for further improvements in the regional climate simulations of ISMR for various sub-regions and contribute

  15. Stress Domains in Si\\(111\\)/a-Si3N4 Nanopixel: Ten-Million-Atom Molecular Dynamics Simulations on Parallel Computers

    Science.gov (United States)

    Omeltchenko, Andrey; Bachlechner, Martina E.; Nakano, Aiichiro; Kalia, Rajiv K.; Vashishta, Priya; Ebbsjö, Ingvar; Madhukar, Anupam; Messina, Paul

    2000-01-01

    Parallel molecular dynamics simulations are performed to determine atomic-level stresses in Si\\(111\\)/Si3N4\\(0001\\) and Si\\(111\\)/a-Si3N4 nanopixels. Compared to the crystalline case, the stresses in amorphous Si3N4 are highly inhomogeneous in the plane of the interface. In silicon below the interface, for a 25 nm square mesa stress domains with triangular symmetry are observed, whereas for a rectangular, 54 nm×33 nm, mesa tensile stress domains \\(~300 Å\\) are separated by Y-shaped compressive domain wall. Maximum stresses in the domains and domain walls are -2 GPa and +2 GPa, respectively.

  16. Stress domains in Si(111)/a-Si3N4 nanopixel: ten-million-atom molecular dynamics simulations on parallel computers

    Science.gov (United States)

    Omeltchenko; Bachlechner; Nakano; Kalia; Vashishta; Ebbsjo; Madhukar; Messina

    2000-01-10

    Parallel molecular dynamics simulations are performed to determine atomic-level stresses in Si(111)/Si(3)N4(0001) and Si(111)/a-Si3N4 nanopixels. Compared to the crystalline case, the stresses in amorphous Si3N4 are highly inhomogeneous in the plane of the interface. In silicon below the interface, for a 25 nm square mesa stress domains with triangular symmetry are observed, whereas for a rectangular, 54 nmx33 nm, mesa tensile stress domains ( approximately 300 A) are separated by Y-shaped compressive domain wall. Maximum stresses in the domains and domain walls are -2 GPa and +2 GPa, respectively.

  17. Breaking News: Utilizing Video Simulations to Improve Educational Leaders' Public Speaking Skills

    Science.gov (United States)

    Friend, Jennifer; Adams, April; Curry, George

    2011-01-01

    This article examines specific uses of video simulations in one educational leadership preparation program to advance future school and district leaders' skills related to public speaking and participation in televised news interviews. One faculty member and two advanced educational leadership candidates share their perspectives of several…

  18. Applicability of Finite-Difference Time-Domain Method to Simulation of Wave Propagation in Cancellous Bone

    Science.gov (United States)

    Nagatani, Yoshiki; Imaizumi, Hirotaka; Fukuda, Takashi; Matsukawa, Mami; Watanabe, Yoshiaki; Otani, Takahiko

    2006-09-01

    In cancellous bone, longitudinal waves often separate into fast and slow waves depending on the alignment of bone trabeculae. This interesting phenomenon becomes an effective tool for the diagnosis of osteoporosis because wave propagation behavior depends on the bone structure. We have, therefore, simulated wave propagation in such a complex medium by the finite-difference time-domain (FDTD) method, using a three-dimensional X-ray computer tomography (CT) model of an actual cancellous bone. In this simulation, experimentally observed acoustic constants of the cortical bone were adopted. As a result, the generation of fast and slow waves was confirmed. The speed of fast waves and the amplitude of slow waves showed good correlations with the bone volume fraction. The simulated results were also compared with the experimental results obtained from the identical cancellous bone.

  19. Simulations of super-structure domain walls in two dimensional assemblies of magnetic nanoparticles

    DEFF Research Database (Denmark)

    Jordanovic, Jelena; Beleggia, Marco; Schiøtz, Jakob

    2015-01-01

    taking the role of the atomic spins. The coupling is, however, different. The superspins interact only by dipolar interactions as exchange coupling between individual nanoparticles may be neglected due to interparticle spacing. We observe that it is energetically favorable to introduce domain walls...... oriented along the long dimension of nanoparticle assemblies rather than along the short dimension. This is unlike what is typically observed in continuous magnetic materials, where the exchange interaction introduces an energetic cost proportional to the area of the domain walls. Structural disorder...

  20. Hamiltonian Switch Metropolis Monte Carlo Simulations for Improved Conformational Sampling of Intrinsically Disordered Regions Tethered to Ordered Domains of Proteins.

    Science.gov (United States)

    Mittal, Anuradha; Lyle, Nicholas; Harmon, Tyler S; Pappu, Rohit V

    2014-08-12

    There is growing interest in the topic of intrinsically disordered proteins (IDPs). Atomistic Metropolis Monte Carlo (MMC) simulations based on novel implicit solvation models have yielded useful insights regarding sequence-ensemble relationships for IDPs modeled as autonomous units. However, a majority of naturally occurring IDPs are tethered to ordered domains. Tethering introduces additional energy scales and this creates the challenge of broken ergodicity for standard MMC sampling or molecular dynamics that cannot be readily alleviated by using generalized tempering methods. We have designed, deployed, and tested our adaptation of the Nested Markov Chain Monte Carlo sampling algorithm. We refer to our adaptation as Hamiltonian Switch Metropolis Monte Carlo (HS-MMC) sampling. In this method, transitions out of energetic traps are enabled by the introduction of an auxiliary Markov chain that draws conformations for the disordered region from a Boltzmann distribution that is governed by an alternative potential function that only includes short-range steric repulsions and conformational restraints on the ordered domain. We show using multiple, independent runs that the HS-MMC method yields conformational distributions that have similar and reproducible statistical properties, which is in direct contrast to standard MMC for equivalent amounts of sampling. The method is efficient and can be deployed for simulations of a range of biologically relevant disordered regions that are tethered to ordered domains.

  1. A New Boundary Model for Simulating Complex and Flexible Wall Bounded Domain in Dissipative Particle Dynamics

    Directory of Open Access Journals (Sweden)

    Saeid Mokhtarian

    2014-01-01

    Full Text Available Despite extensive area of applications, simulation of complex wall bounded problems or any deformable boundary is still a challenge in a Dissipative Particle Dynamics simulation. This limitation is rooted in the soft force nature of DPD and the fact that we need to use an antipenetration model for escaped particles. In the present paper, we propose a new model of antipenetration which preserves the conservation of linear momentum on the boundaries and enables us to simulate complex and flexible boundaries. Finally by performing numerical simulations, we demonstrate the validity of our new model.

  2. The finite-difference time-domain method for electromagnetics with Matlab simulations

    CERN Document Server

    Elsherbeni, Atef Z

    2016-01-01

    This book introduces the powerful Finite-Difference Time-Domain method to students and interested researchers and readers. An effective introduction is accomplished using a step-by-step process that builds competence and confidence in developing complete working codes for the design and analysis of various antennas and microwave devices.

  3. Assembly of the transmembrane domain of E. coli PhoQ histidine kinase: implications for signal transduction from molecular simulations.

    Science.gov (United States)

    Lemmin, Thomas; Soto, Cinque S; Clinthorne, Graham; DeGrado, William F; Dal Peraro, Matteo

    2013-01-01

    The PhoQP two-component system is a signaling complex essential for bacterial virulence and cationic antimicrobial peptide resistance. PhoQ is the histidine kinase chemoreceptor of this tandem machine and assembles in a homodimer conformation spanning the bacterial inner membrane. Currently, a full understanding of the PhoQ signal transduction is hindered by the lack of a complete atomistic structure. In this study, an atomistic model of the key transmembrane (TM) domain is assembled by using molecular simulations, guided by experimental cross-linking data. The formation of a polar pocket involving Asn202 in the lumen of the tetrameric TM bundle is crucial for the assembly and solvation of the domain. Moreover, a concerted displacement of the TM helices at the periplasmic side is found to modulate a rotation at the cytoplasmic end, supporting the transduction of the chemical signal through a combination of scissoring and rotational movement of the TM helices.

  4. Assembly of the transmembrane domain of E. coli PhoQ histidine kinase: implications for signal transduction from molecular simulations.

    Directory of Open Access Journals (Sweden)

    Thomas Lemmin

    Full Text Available The PhoQP two-component system is a signaling complex essential for bacterial virulence and cationic antimicrobial peptide resistance. PhoQ is the histidine kinase chemoreceptor of this tandem machine and assembles in a homodimer conformation spanning the bacterial inner membrane. Currently, a full understanding of the PhoQ signal transduction is hindered by the lack of a complete atomistic structure. In this study, an atomistic model of the key transmembrane (TM domain is assembled by using molecular simulations, guided by experimental cross-linking data. The formation of a polar pocket involving Asn202 in the lumen of the tetrameric TM bundle is crucial for the assembly and solvation of the domain. Moreover, a concerted displacement of the TM helices at the periplasmic side is found to modulate a rotation at the cytoplasmic end, supporting the transduction of the chemical signal through a combination of scissoring and rotational movement of the TM helices.

  5. Numerical Absorbing Boundary Conditions Based on a Damped Wave Equation for Pseudospectral Time-Domain Acoustic Simulations

    Science.gov (United States)

    Reche-López, Pedro; Hernández, Erwin

    2014-01-01

    In the context of wave-like phenomena, Fourier pseudospectral time-domain (PSTD) algorithms are some of the most efficient time-domain numerical methods for engineering applications. One important drawback of these methods is the so-called Gibbs phenomenon. This error can be avoided by using absorbing boundary conditions (ABC) at the end of the simulations. However, there is an important lack of ABC using a PSTD methods on a wave equation. In this paper, we present an ABC model based on a PSTD damped wave equation with an absorption parameter that depends on the position. Some examples of optimum variation profiles are studied analytically and numerically. Finally, the results of this model are also compared to another ABC model based on an hybrid formulation of the scalar perfectly matched layer. PMID:24737966

  6. Micro-magnetic simulation study on the magnetic particle imaging performance of anisotropic mono-domain particles.

    Science.gov (United States)

    Weizenecker, Jürgen; Gleich, Bernhard; Rahmer, Jürgen; Borgert, Jörn

    2012-11-21

    The performance of magnetic mono-domain particles is of crucial importance in magnetic particle imaging (MPI). So far, the behavior of mono-domain particles has been modeled within the framework of Langevin theory. This theory predicts the dependence of the MPI signal on the particle core size, but cannot account for the influence of the shape, i.e. the anisotropy of the particle core. In this study we present the first micro-magnetic ab initio simulation of spectra of anisotropic particles with different core diameters in an oscillating magnetic field at 25 and 100 kHz. We find that the MPI signal strongly depends on the anisotropy of the magnetic core. Thus, a difference of 3 nm between the principal axes of a prolate ellipsoid with the volume of a 30 nm sphere can result in a complete loss of the MPI signal. Smaller anisotropies, however, can increase the MPI performance of the particle. The simulations show that the effect of the anisotropy on the MPI signal depends on the frequency of the oscillating magnetic field. At 100 kHz, the optimal signal is found at smaller anisotropies than at 25 kHz. Furthermore, the simulations show that experimental spectroscopic results for Resovist® can only be explained quantitatively by particles with a magnetic core size of at least 25 nm.

  7. Flow Simulation Around Cambered Airfoil by Using Conformal Mapping and Intermediate Domain in Lattice Boltzmann Method

    Science.gov (United States)

    Poozesh, Amin; Mirzaei, Masoud

    2017-01-01

    In this paper the developed interpolation lattice Boltzmann method is used for simulation of unsteady fluid flow. It combines the desirable features of the lattice Boltzmann and the Joukowski transformation methods. This approach has capability to simulate flow around curved boundary geometries such as airfoils in a body fitted grid system. Simulation of unsteady flow around a cambered airfoil in a non-uniform grid for the first time is considered to show the capability of this method for modeling of fluid flow around complex geometries and complicated long-term periodic flow phenomena. The developed solver is also coupled with a fast adaptive grid generator. In addition, the new approach retains all the advantages of the standard lattice Boltzmann method. The Strouhal number, the pressure, the drag and the lift coefficients obtained from the simulations agree well with classical computational fluid dynamics simulations. Numerical studies for various test cases illustrate the strength of this new approach.

  8. Use of media and public-domain Internet sources for detection and assessment of plant health threats

    Directory of Open Access Journals (Sweden)

    David M. Hartley

    2011-09-01

    Full Text Available Event-based biosurveillance is a recognized approach to early warning and situational awareness of emerging health threats. In this study, we build upon previous human and animal health work to develop a new approach to plant pest and pathogen surveillance. We show that monitoring public domain electronic media for indications and warning of epidemics and associated social disruption can provide information about the emergence and progression of plant pest infestation or disease outbreak. The approach is illustrated using a case study, which describes a plant pest and pathogen epidemic in China and Vietnam from February 2006 to December 2007, and the role of ducks in contributing to zoonotic virus spread in birds and humans. This approach could be used as a complementary method to traditional plant pest and pathogen surveillance to aid global and national plant protection officials and political leaders in early detection and timely response to significant biological threats to plant health, economic vitality, and social stability. This study documents the inter-relatedness of health in human, animal, and plant populations and emphasizes the importance of plant health surveillance.

  9. How Large Is the "Public Domain"? A Comparative Analysis of Ringer's 1961 Copyright Renewal Study and HathiTrust CRMS Data

    Science.gov (United States)

    Wilkin, John P.

    2017-01-01

    The 1961 Copyright Office study on renewals, authored by Barbara Ringer, has cast an outsized influence on discussions of the U.S. 1923-1963 public domain. As more concrete data emerge from initiatives such as the large-scale determination process in the Copyright Review Management System (CRMS) project, questions are raised about the reliability…

  10. Wind Energy System Time-domain (WEST) analyzers using hybrid simulation techniques

    Science.gov (United States)

    Hoffman, J. A.

    1979-01-01

    Two stand-alone analyzers constructed for real time simulation of the complex dynamic characteristics of horizontal-axis wind energy systems are described. Mathematical models for an aeroelastic rotor, including nonlinear aerodynamic and elastic loads, are implemented with high speed digital and analog circuitry. Models for elastic supports, a power train, a control system, and a rotor gimbal system are also included. Limited correlation efforts show good comparisons between results produced by the analyzers and results produced by a large digital simulation. The digital simulation results correlate well with test data.

  11. Nonlinear Time-Domain Simulation of Ship Capsizing in Beam Seas.

    Science.gov (United States)

    1997-11-01

    1991; Lin & Yue, 1990; Bingham, et al., 1993) or the Rankine source methods (eg, Nakos & Sclavounos, 1990). Linear methods have been very successful...A.E. (1981), "Users Manual for the Standard Ship Motion Program, SMP," DTNSRDC Report SPD-0936-01. Nakos , D.E. and Sclavounos, P.D. (1990), Ship...1991), Lin k Yue (1990), Bingham, et al, (1993)) or the Rank- ine source methods (e.g., Nakos k Sclavounos (1990)). Linear frequency-domain methods

  12. Accurate finite-difference time-domain simulation of anisotropic media by subpixel smoothing.

    Science.gov (United States)

    Oskooi, Ardavan F; Kottke, Chris; Johnson, Steven G

    2009-09-15

    Finite-difference time-domain methods suffer from reduced accuracy when discretizing discontinuous materials. We previously showed that accuracy can be significantly improved by using subpixel smoothing of the isotropic dielectric function, but only if the smoothing scheme is properly designed. Using recent developments in perturbation theory that were applied to spectral methods, we extend this idea to anisotropic media and demonstrate that the generalized smoothing consistently reduces the errors and even attains second-order convergence with resolution.

  13. Efficient time-domain simulation of nonlinear, state-space, transmission-line models of the cochlea (L).

    Science.gov (United States)

    Pan, Shuokai; Elliott, Stephen J; Teal, Paul D; Lineton, Ben

    2015-06-01

    Nonlinear models of the cochlea are best implemented in the time domain, but their computational demands usually limit the duration of the simulations that can reasonably be performed. This letter presents a modified state space method and its application to an example nonlinear one-dimensional transmission-line cochlear model. The sparsity pattern of the individual matrices for this alternative formulation allows the use of significantly faster numerical algorithms. Combined with a more efficient implementation of the saturating nonlinearity, the computational speed of this modified state space method is more than 40 times faster than that of the original formulation.

  14. Numerical simulation of partially coherent broadband optical imaging using the finite-difference time-domain method.

    Science.gov (United States)

    Çapoğlu, İlker R; White, Craig A; Rogers, Jeremy D; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim

    2011-05-01

    Rigorous numerical modeling of optical systems has attracted interest in diverse research areas ranging from biophotonics to photolithography. We report the full-vector electromagnetic numerical simulation of a broadband optical imaging system with partially coherent and unpolarized illumination. The scattering of light from the sample is calculated using the finite-difference time-domain (FDTD) numerical method. Geometrical optics principles are applied to the scattered light to obtain the intensity distribution at the image plane. Multilayered object spaces are also supported by our algorithm. For the first time, numerical FDTD calculations are directly compared to and shown to agree well with broadband experimental microscopy results.

  15. Full molecular dynamics simulations of liquid water and carbon tetrachloride for two-dimensional Raman spectroscopy in the frequency domain

    CERN Document Server

    Jo, Ju-Yeon; Tanimura, Yoshitaka

    2016-01-01

    Frequency-domain two-dimensional Raman signals, which are equivalent to coherent two-dimensional Raman scattering (COTRAS) signals, for liquid water and carbon tetrachloride were calculated using an equilibrium-nonequilibrium hybrid MD simulation algorithm. We elucidate mechanisms governing the 2D signal pro?les involving anharmonic mode-mode coupling and the nonlinearities of the polarizability for the intermolecular and intramolecular vibrational modes. The predicted signal pro?les and intensities can be utilized to analyze recently developed single-beam 2D spectra, whose signals are generated from a coherently controlled pulse, allowing the single-beam measurement to be carried out more efficiently.

  16. The EAGLE simulation of galaxy formation: public release of halo and galaxy catalogues

    CERN Document Server

    McAlpine, Stuart; Schaller, Matthieu; Trayford, James W; Qu, Yan; Furlong, Michelle; Bower, Richard G; Crain, Robert A; Schaye, Joop; Theuns, Tom; Vecchia, Claudio Dalla; Frenk, Carlos S; McCarthy, Ian G; Jenkins, Adrian; Rosas-Guevara, Yetli; White, Simon D M; Baes, Maarten; Camps, Peter; Lemson, Gerard

    2015-01-01

    We present the public data release of halo and galaxy catalogues extracted from the EAGLE suite of cosmological hydrodynamical simulations of galaxy formation. These simulations were performed with an enhanced version of the GADGET code that includes a modified hydrodynamics solver, time-step limiter and subgrid treatments of baryonic physics, such as stellar mass loss, element-by-element radiative cooling, star formation and feedback from star formation and black hole accretion. The simulation suite includes runs performed in volumes ranging from 25 to 100 comoving megaparsecs per side, with numerical resolution chosen to marginally resolve the Jeans mass of the gas at the star formation threshold. The free parameters of the subgrid models for feedback are calibrated to the redshift z=0 galaxy stellar mass function, galaxy sizes and black hole mass - stellar mass relation. The simulations have been shown to match a wide range of observations for present-day and higher-redshift galaxies. The raw particle data...

  17. The structure of MHD turbulence under an external magnetic field: results from simulations on elongated domains

    Science.gov (United States)

    Zhai, X. M.; Yeung, P. K.

    2016-11-01

    Turbulence in an electrically conducting fluid in the limit of low magnetic Reynolds number is, because of the Lorentz force due to an external magnetic field, very different from classical turbulence at both the large scales and the small scales. The importance of minimizing finite domain-size effects on the large scale development has often tended to limit the Reynolds number reached in the past. In this work we use periodic domains stretched along the magnetic field with aspect ratio up to 8 and beyond. The initial state is obtained from decaying isotropic turbulence with large-eddy length scales of order 1% of the length of the domain. After a transient period the kinetic energy returns to a power law decay while the integral length scales in the direction parallel to the magnetic field show preferential growth. At early times the parallel velocity component becomes stronger than the other two but this anisotropy is subsequently reversed under the combined effects of anisotropic Joule dissipation and viscous dissipation. The small scales show characteristics of quasi two-dimensional behavior in the transverse plane. Results over a range of magnetic interaction parameters and Reynolds numbers are compared with known theoretical predictions. Supported by NSF Grant CBET-1510749 and supercomputer resources at TACC/XSEDE and ALCF.

  18. Timetable-based simulation method for choice set generation in large-scale public transport networks

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Kjær; Anderson, Marie Karen; Nielsen, Otto Anker

    2016-01-01

    The composition and size of the choice sets are a key for the correct estimation of and prediction by route choice models. While existing literature has posed a great deal of attention towards the generation of path choice sets for private transport problems, the same does not apply to public...... transport problems. This study proposes a timetable-based simulation method for generating path choice sets in a multimodal public transport network. Moreover, this study illustrates the feasibility of its implementation by applying the method to reproduce 5131 real-life trips in the Greater Copenhagen Area...

  19. Finite-difference time-domain-based optical microscopy simulation of dispersive media facilitates the development of optical imaging techniques

    Science.gov (United States)

    Zhang, Di; Capoglu, Ilker; Li, Yue; Cherkezyan, Lusik; Chandler, John; Spicer, Graham; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim

    2016-06-01

    Combining finite-difference time-domain (FDTD) methods and modeling of optical microscopy modalities, we previously developed an open-source software package called Angora, which is essentially a "microscope in a computer." However, the samples being simulated were limited to nondispersive media. Since media dispersions are common in biological samples (such as cells with staining and metallic biomarkers), we have further developed a module in Angora to simulate samples having complicated dispersion properties, thereby allowing the synthesis of microscope images of most biological samples. We first describe a method to integrate media dispersion into FDTD, and we validate the corresponding Angora dispersion module by applying Mie theory, as well as by experimentally imaging gold microspheres. Then, we demonstrate how Angora can facilitate the development of optical imaging techniques with a case study.

  20. Measurements And Particle In Cell vs. Fluid Simulations Of A New Time Domain Impedance Probe For Ionospheric Plasma Characterization

    Science.gov (United States)

    Spencer, E. A.; Russ, S.; Kerrigan, B.; Leggett, K.; Mullins, J.; Clark, D. C.; Mizell, J.; Gollapalli, R.; Vassiliadis, D.; Lusk, G. D.

    2015-12-01

    A plasma impedance probe is used to obtain plasma parameters in the ionosphere by measuring the magnitude, shape and location of resonances in the frequency spectrum when a probe structure is driven with RF excitation. The measured magnitude and phase response with respect to frequency can be analyzed via analytical and simulational means. We have designed and developed a new Time Domain Impedance Probe capable of making measurements of absolute electron density and electron neutral collision frequency at temporal and spatial resolutions not previously attained. A single measurement can be made in a time as short as 50 microseconds, which yields a spatial resolution of 0.35 meters for a satellite orbital velocity of 7 km/s. The method essentially consists of applying a small amplitude time limited voltage signal into a probe and measuring the resulting current response. The frequency bandwidth of the voltage signal is selected in order that the electron plasma resonances are observable. A prototype of the instrument will be flown in October 2015 on a NASA Undergraduate Student Instrument Progam (USIP) sounding rocket launched out of Wallops Flight Facility. To analyze the measurements, we use a Particle In Cell (PIC) kinetic simulation to calculate the impedance of a dipole antenna immersed in a plasma. The electromagnetic solver utilizes the Finite Difference Time Domain method, while the particle to grid and grid to particle interpolation schemes are standard. The plasma sheath formation electron flux into the dipole surface is not included. The bulk velocity of the plasma around the dipole is assumed to be zero. For completeness, the hot plasma and nonlinear effects of probe plasma interaction are explored, including the appearance of cyclotron harmonics. In this work the electron neutral collisions are simulated via a Poisson process approximation. Our results are compared to sounding rocket data from the NASA Tropical Storms mission in 2007, as well as the

  1. Diffusion in Altered Tonalite Sample Using Time Domain Diffusion Simulations in Tomographic Images Combined with Lab-scale Diffusion Experiments

    Science.gov (United States)

    Voutilainen, M.; Sardini, P.; Togneri, L.; Siitari-Kauppi, M.; Timonen, J.

    2010-12-01

    In this work an effect of rock heterogeneity on diffusion was investigated. Time domain diffusion simulations were used to compare behavior of diffusion in homogeneous and heterogeneous 3D media. Tomographic images were used as heterogeneous rock media. One altered tonalite sample from Sievi, Finland, was chosen as test case for introduced analysis procedure. Effective diffusion coefficient of tonalite sample was determined with lab-scale experiments and the same coefficient was used also for homogeneous media. Somewhat technically complicated mathematical solution for analysis of through diffusion experiment is shortly described. Computed tomography (CT) is already quite widely used in many geological, petrological, and paleontological applications when the three-dimensional (3D) structure of the material is of interest, and is an excellent method for gaining information especially about its heterogeneity, grain size, or porosity. In addition to offering means for quantitative characterization, CT provides a lot of qualitative information [1]. A through -diffusion laboratory experiment using radioactive tracer was fitted using the Time Domain Diffusion (TDD) method. This rapid particle tracking method allows simulation of the heterogeneous diffusion based on pore-scale images and local values of diffusivities [2]. As a result we found out that heterogeneity has only a small effect to diffusion coefficient and in-diffusion profile for used geometry. Also direction dependency was tested and was found to be negligible. Whereas significant difference between generally accepted value and value obtained from simulations for constant m in Archie’s law was found. [1] Voutilainen, M., Siitari-Kauppi, M., Sardini, P., and Timonen, J., (2010). On pore-space characterization of an altered tonalite by X-ray µCT and the 14C-PMMA method (in progress). [2] Sardini, P., Robinet, J., Siitari-Kauppi, M., Delay, F., and Hellmuth, K-H, (2007). On direct simulation of heterogeneous

  2. Coupling of Two Absorbing Boundary Conditions for 2D Time-Domain Simulations of Free Surface Gravity Waves

    Science.gov (United States)

    Clément, A.

    1996-06-01

    The numerical simulation of nonlinear gravity waves propagating at the surface of a perfect fluid is now usually solved by totally nonlinear time-domain numerical models in two dimensions, and this approach is being extended to three dimensions. The original initial boundary value problem is posed in an unbounded region, extending horizontally up to infinity to model the sea. Its numerical solution requires truncating the domain at a finite distance. Unfortunately, no exact nonreflecting boundary condition on the truncating surface exists in this time-domain formulation. The proposed strategy is based on the coupling of two previously known methods in order to benefit from their different, and complementary, bandwidth: the numerical "beach," very efficient in the high frequency range; and a piston-like Neumann condition, asymptotically ideal for low frequencies. The coupling method gives excellent results in the whole range of frequencies of interest and is as easy to implement in nonlinear as in linear versions. One of its major advantages is that it does not require any spectral knowledge of the incident waves.

  3. An oversampling technique for the multiscale finite volume method to simulate electromagnetic responses in the frequency domain

    CERN Document Server

    Mata, Luz Angelica Caudillo; Schwarzbach, Christoph

    2016-01-01

    In order to reduce the computational cost of the simulation of electromagnetic responses in geophysical settings that involve highly heterogeneous media, we develop a multiscale finite volume method with oversampling for the quasi-static Maxwell's equations in the frequency domain. We assume a coarse mesh nested within a fine mesh that accurately discretizes the problem. For each coarse cell, we independently solve a local version of the original Maxwell's system subject to linear boundary conditions on an extended domain, which includes the coarse cell and a neighborhood of fine cells around it. The local Maxwell's system is solved using the fine mesh contained in the extended domain and the mimetic finite volume method. Next, these local solutions (basis functions) together with a weak-continuity condition are used to construct a coarse-mesh version of the global problem. The basis functions can be used to obtain the fine-mesh details from the solution of the coarse-mesh problem. Our approach leads to a sig...

  4. A Generic Discrete-Event Simulation Model for Outpatient Clinics in a Large Public Hospital

    Directory of Open Access Journals (Sweden)

    Waressara Weerawat

    2013-01-01

    Full Text Available The orthopedic outpatient department (OPD ward in a large Thai public hospital is modeled using Discrete-Event Stochastic (DES simulation. Key Performance Indicators (KPIs are used to measure effects across various clinical operations during different shifts throughout the day. By considering various KPIs such as wait times to see doctors, percentage of patients who can see a doctor within a target time frame, and the time that the last patient completes their doctor consultation, bottlenecks are identified and resource-critical clinics can be prioritized. The simulation model quantifies the chronic, high patient congestion that is prevalent amongst Thai public hospitals with very high patient-to-doctor ratios. Our model can be applied across five different OPD wards by modifying the model parameters. Throughout this work, we show how DES models can be used as decision-support tools for hospital management.

  5. A generic discrete-event simulation model for outpatient clinics in a large public hospital.

    Science.gov (United States)

    Weerawat, Waressara; Pichitlamken, Juta; Subsombat, Peerapong

    2013-01-01

    The orthopedic outpatient department (OPD) ward in a large Thai public hospital is modeled using Discrete-Event Stochastic (DES) simulation. Key Performance Indicators (KPIs) are used to measure effects across various clinical operations during different shifts throughout the day. By considering various KPIs such as wait times to see doctors, percentage of patients who can see a doctor within a target time frame, and the time that the last patient completes their doctor consultation, bottlenecks are identified and resource-critical clinics can be prioritized. The simulation model quantifies the chronic, high patient congestion that is prevalent amongst Thai public hospitals with very high patient-to-doctor ratios. Our model can be applied across five different OPD wards by modifying the model parameters. Throughout this work, we show how DES models can be used as decision-support tools for hospital management.

  6. Time-Domain Simulations of Transient Species in Experimentally Relevant Environments

    Energy Technology Data Exchange (ETDEWEB)

    Ueltschi, Tyler W.; Fischer, Sean A.; Apra, Edoardo; Tarnovsky, Alexander N.; Govind, Niranjan; El-Khoury, Patrick Z.; Hess, Wayne P.

    2016-02-04

    Simulating the spectroscopic properties of short-lived thermal and photochemical reaction intermediates and products is a challenging task, as these species often feature atypical molecular and electronic structures. The complex environments in which such species typically reside in practice add further complexity to the problem. Herein, we tackle this problem in silico using ab initio molecular dynamics (AIMD) simulations, employing iso-CHBr3, namely H(Br)C-Br-Br, as a prototypical system. This species was chosen because it features both a non-conventional C-Br-Br bonding pattern, as well as a strong dependence of its spectral features on the local environment in which it resides, as illustrated in recent experimental reports. The spectroscopic properties of iso-CHBr3 were measured by several groups that captured this transient intermediate in the photochemistry of CHBr3 in the gas phase, in rare gas matrices at 5K, and in solution under ambient laboratory conditions. We simulate the UV-Vis and IR spectra of iso-CHBr3 in all three media, including a Ne cluster (64 atoms) and a methylcyclohexane cage (14 solvent molecules) representative of the matrix isolated and solvated species. We exclusively perform fully quantum mechanical static and dynamic simulations. By comparing our condensed phase simulations to their experimental analogues, we stress the importance of (i) conformational sampling, even at cryogenic temperatures, and (ii) using a fully quantum mechanical description of both solute and bath to properly account for the experimental observables.

  7. Anxiolytic-like effect of oxytocin in the simulated public speaking test

    OpenAIRE

    Oliveira, Danielle Chaves Gomes de; Zuardi, Antonio Waldo; Graeff, Frederico Guilherme; Queiroz, Regina Helena Costa; Crippa, José Alexandre de Souza

    2012-01-01

    Oxytocin (OT) is known to be involved in anxiety, as well as cardiovascular and hormonal regulation. The objective of this study was to assess the acute effect of intranasally administered OT on subjective states, as well as cardiovascular and endocrine parameters, in healthy volunteers (n = 14) performing a simulated public speaking test. OT or placebo was administered intranasally 50 min before the test. Assessments were made across time during the experimental session: (1) baseline (-30 mi...

  8. Air quality assessment and sensitivity studies by numerical simulations over a regional domain

    Science.gov (United States)

    Del Frate, S.; Gallai, I.; Giaiotti, D.; Montanari, F.; Petrini, A.; Pillon, A.; Pinat, T.; Stel, F.; Tassan, F.; Turoldo, F.

    2010-09-01

    Air quality assessment over areas characterized by complex orography and land use, with spot like distributed urbanization and industrial activities, is an hard task because the use of in situ measurements is limited by the short spatial range representativeness of the recorded data. In such a situation the use of numerical model simulations is the essential tool for the assessment of pollutants concentration, both on average and on peak episodes, according the EU and national directives. Furthermore simulations are the main tool for the projection of the effects expected by the implementation of actions aimed to improve air quality. In this work we present the results of the operational application of an eulerian model, namely FARM (http://www.aria-net.it/), for the air quality assessment over the Northeastern most Italian region. The updated inventory of all the relevant anthropogenic and the biogenic sources has been used to generate the emissions of pollutants which are dispersed according to meteorological fields, that have been computed on the base of weather stations and radiosoundings measurements. Boundary conditions of concentrations have been taken from the national database. The dispersive model is working off line with a spatial resolution of 4 km generating hourly concentration and deposition fields. Air quality measurements are used to evaluate the representativeness of the simulated fields. Results of statistical tests, which are applied to grid points and to areal sets of measurements and corresponding simulation data, are described in detail. A general approach to the air quality simulations reliability evaluation is summarized. The sensitivity of the model to changes in emission inventory inputs is presented too. Eleven different inventory scenarios are considered according to hypothetical administrative actions aimed to improve the air quality across the next ten years. The sensitivity is presented as a mathematical measure of the distance of

  9. The numerical simulation on electromagnetic wave attenuation characteristics of coal face in time-frequency domain

    Institute of Scientific and Technical Information of China (English)

    YU Shi-jian; Cheng Jiu-long; LIU Jia-qi

    2007-01-01

    This paper took the abnormal geological objects with high or low resistivity in the coal face as the background to establish the physical model. 2D forward numerical simulation for electromagnetic wave equation was implemented by the finite-difference scheme. According to the simulative results, the attenuation-absorption coefficient were calculated respectively based on field intensity and frequency shift parameter. Research result indicates, when coal-bed contains high electric resistivity geological abnormal object or low electric resistivity geological abnormal object, absorption attenuation function researched by frequency shift parameter of electromagnetic wave signal is more sensitive than by electromagnetic field intensity parameter.

  10. Transfer-matrix approach for finite-difference time-domain simulation of periodic structures.

    Science.gov (United States)

    Deinega, Alexei; Belousov, Sergei; Valuev, Ilya

    2013-11-01

    Optical properties of periodic structures can be calculated using the transfer-matrix approach, which establishes a relation between amplitudes of the wave incident on a structure with transmitted or reflected waves. The transfer matrix can be used to obtain transmittance and reflectance spectra of finite periodic structures as well as eigenmodes of infinite structures. Traditionally, calculation of the transfer matrix is performed in the frequency domain and involves linear algebra. In this work, we present a technique for calculation of the transfer matrix using the finite-difference time-domain (FDTD) method and show the way of its implementation in FDTD code. To illustrate the performance of our technique we calculate the transmittance spectra for opal photonic crystal slabs consisting of multiple layers of spherical scatterers. Our technique can be used for photonic band structure calculations. It can also be combined with existing FDTD methods for the analysis of periodic structures at an oblique incidence, as well as for modeling point sources in a periodic environment.

  11. Domains of quality of life: results of a three-stage Delphi consensus procedure among patients, family of patients, clinicians, scientists and the general public.

    Science.gov (United States)

    Pietersma, Suzanne; de Vries, Marieke; van den Akker-van Marle, M Elske

    2014-06-01

    Our key objective is to identify the core domains of health-related quality of life (QoL). Health-related QoL utility scales are commonly used in economic evaluations to assess the effectiveness of health-care interventions. However, health-care interventions are likely to affect QoL in a broader sense than is quantifiable with traditional scales. Therefore, measures need to go beyond these scales. Unfortunately, there is no consensus in the scientific literature on the essential domains of QoL. We conducted a three-stage online Delphi consensus procedure to identify the key domains of health-related QoL. Five stakeholder groups (i.e., patients, family of patients, clinicians, scientists and general public) were asked, on three consecutive occasions, what they perceive as the most important domains of health-related QoL. An analysis of existing (health-related) QoL and well-being measurements formed the basis of the Delphi-procedure. In total, 42 domains of QoL were judged, covering physical, mental and social aspects. All participants rated 'self-acceptance', 'self-esteem' and 'good social contacts' as essential. Strikingly, mental and social domains are perceived as more essential than physical domains across stakeholders groups. In traditionally used health-related QoL utility measures, physical domains like 'mobility' are prominently present. The Delphi-procedure shows that health-related QoL (utility) scales need to put sufficient emphasis on mental and social domains to capture aspects of QoL that are essential to people.

  12. Insight into the interactive residues between two domains of human somatic Angiotensin-converting enzyme and Angiotensin II by MM-PBSA calculation and steered molecular dynamics simulation.

    Science.gov (United States)

    Guan, Shan-shan; Han, Wei-wei; Zhang, Hao; Wang, Song; Shan, Ya-ming

    2016-01-01

    Angiotensin-converting enzyme (ACE), a membrane-bound zinc metallopeptidase, catalyzes the formation of Angiotensin-II (AngII) and the deactivation of bradykinin in the renin-angiotensin-aldosterone and kallikrein-kinin systems. As a hydrolysis product of ACE, AngII is regarded as an inhibitor and displays stronger competitive inhibition in the C-domain than the N-domain of ACE. However, the AngII binding differences between the two domains and the mechanisms behind AngII dissociation from the C-domain are rarely explored. In this work, molecular docking, Molecular Mechanics/Poisson-Boltzmann Surface Area calculation, and steered molecular dynamics (SMD) are applied to explore the structures and interactions in the binding or unbinding of AngII with the two domains of human somatic ACE. Calculated free energy values suggest that the C-domain-AngII complex is more stable than the N-domain-AngII complex, consistent with available experimental data. SMD simulation results imply that electrostatic interaction is dominant in the dissociation of AngII from the C-domain. Moreover, Gln106, Asp121, Glu123, and Tyr213 may be the key residues in the unbinding pathway of AngII. The simulation results in our work provide insights into the interactions between the two domains of ACE and its natural peptide inhibitor AngII at a molecular level. Moreover, the results provide theoretical clues for the design of new inhibitors.

  13. Simulation modeling and tobacco control: creating more robust public health policies.

    Science.gov (United States)

    Levy, David T; Bauer, Joseph E; Lee, Hye-Ryeon

    2006-03-01

    Although previous empirical studies have shown that tobacco control policies are effective at reducing smoking rates, such studies have proven of limited effectiveness in distinguishing how the effect of policies depend on the other policies in place, the length of adjustment period, the way the policy is implemented, and the demographic groups considered. An alternative and complementary approach to purely statistical equations is simulation models. We describe the SimSmoke simulation model and how we used it to assess tobacco control policy in a specific case study. Simulation models are not only useful for policy prediction and planning but also may help to broaden our understanding of the role of different public health policies within a complex, dynamic social system.

  14. Bio-inspired seismic metamaterials: Time domain simulations in transformed crystals

    CERN Document Server

    Aznavourian, Ronald; Brule, Stephane; Enoch, Stefan; Guenneau, Sebastien

    2016-01-01

    We introduce the concept of transformation crystallography which consists of the application of geometric transforms to periodic structures. We consider motifs with three-fold, four-fold and six-fold symmetries according to the crystallographic restriction theorem. Furthermore, we define motifs with five-fold symmetry such as quasi-crystals generated by a cut-and-projection method. We analyze elastic wave propagation in the transformed crystals and (Penrose-type) quasi-crystals with the finite difference time domain freeware SimSonic. We consider geometric transforms underpinning the design of seismic cloaks with square, circular, elliptical and peanut shapes in the context of triangular, square and honeycomb crystals. Interestingly, the use of morphing techniques leads to the design of cloaks with interpolated geometries reminiscent of Victor Vasarely's artwork. Employing the case of transformed graphene-like (honeycomb) structures allows one to draw useful analogies between large-scale seismic metamaterials...

  15. Modeling laser-induced periodic surface structures: Finite-difference time-domain feedback simulations

    Energy Technology Data Exchange (ETDEWEB)

    Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in ' t Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2014-03-14

    A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.

  16. Modeling laser-induced periodic surface structures: Finite-difference time-domain feedback simulations

    Science.gov (United States)

    Skolski, J. Z. P.; Römer, G. R. B. E.; Vincenc Obona, J.; Huis in't Veld, A. J.

    2014-03-01

    A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by "ablation after each laser pulse," according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to "grow" either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.

  17. Dynamic Domains of DTS: Simulations of a Spherical Magnetized Couette Flow

    CERN Document Server

    Kaplan, Elliot; Schaeffer, Nathanaël

    2016-01-01

    The Derviche Tourneur Sodium experiment, a spherical Couette magnetohydrodynamics experi- ment with liquid sodium as the medium and a dipole magnetic field imposed from the inner sphere, recently underwent upgrades to its diagnostics to better characterize the flow and induced magnetic fields with global rotation. In tandem with the upgrades, a set of direct numerical simulations were run with the xshells code [1] to give a more complete view of the fluid and magnetic dynamics at various rotation rates of the inner and outer spheres. These simulations reveal several dynamic regimes, determined by the Rossby number. At positive differential rotation there is a regime of quasigeostrophic flow, with low levels of fluctuations near the outer sphere. Negative differential rotation shows a regime of what appear to be saturated hydrodynamic instabilities at low negative differential rotation, followed by a regime where filamentary structures develop at low latitudes and persist over five to ten differential rotation...

  18. Time Domain Simulations of Chemical Bonding Effects in Surface-Enhanced Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, Patrick Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bylaska, Eric J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hess, Wayne P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-11-04

    We employ the atom-centered density-matrix propagation method to illustrate how time-dependent structural and conformational changes affect the electronic structure and derived spectroscopic properties of a prototypical finite metal cluster-bound π-conjugated organic, namely the Ag7-benzenethiol complex. We find that the calculated spectroscopic properties are dictated by large amplitude motion which controls the coupling between the aromatic ring of the molecule and the metal cluster. The simulated vibrational spectra of Ag7-benzenethiol are in accord with previous experiments which probe Raman scattering from benzenethiol adsorbed on silver surfaces.

  19. Simulating net particle production and chiral magnetic current in a CP-odd domain

    CERN Document Server

    Fukushima, Kenji

    2015-01-01

    We elucidate the numerical formulation to simulate net production of particles and anomalous currents with CP-breaking background fields which cause an imbalance of particles over anti-particles. For a concrete demonstration we numerically impose pulsed electric and magnetic fields to observe that the dynamical chiral magnetic current follows together with the net particle production. The produced particle density is quantitatively consistent with the axial anomaly, while the chiral magnetic current is suppressed by a delay before the the onset of the current generation.

  20. Measuring the Benefits of Public Chargers and Improving Infrastructure Deployments Using Advanced Simulation Tools: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric; Neubauer. Jeremy; Burton, Evan

    2015-02-01

    With support from the U.S. Department of Energy's Vehicle Technologies Office, the National Renewable Energy Laboratory developed BLAST-V -- the Battery Lifetime Analysis and Simulation Tool for Vehicles. The addition of high-resolution spatial-temporal travel histories enables BLAST-V to investigate user-defined infrastructure rollouts of publically accessible charging infrastructure, as well as quantify impacts on vehicle and station owners in terms of improved vehicle utility and station throughput. This paper presents simulation outputs from BLAST-V that quantify the utility improvements of multiple distinct rollouts of publically available Level 2 electric vehicle supply equipment (EVSE) in the Seattle, Washington, metropolitan area. Publically available data on existing Level 2 EVSE are also used as an input to BLAST-V. The resulting vehicle utility is compared to a number of mock rollout scenarios. Discussion focuses on the estimated number of Level 2 stations necessary to substantially increase vehicle utility and how stations can be strategically sited to maximize their potential benefit to prospective electric vehicle owners.

  1. Preliminary Molecular Dynamic Simulations of the Estrogen Receptor Alpha Ligand Binding Domain from Antagonist to Apo

    Directory of Open Access Journals (Sweden)

    Adrian E. Roitberg

    2008-06-01

    Full Text Available Estrogen receptors (ER are known as nuclear receptors. They exist in the cytoplasm of human cells and serves as a DNA binding transcription factor that regulates gene expression. However the estrogen receptor also has additional functions independent of DNA binding. The human estrogen receptor comes in two forms, alpha and beta. This work focuses on the alpha form of the estrogen receptor. The ERα is found in breast cancer cells, ovarian stroma cells, endometrium, and the hypothalamus. It has been suggested that exposure to DDE, a metabolite of DDT, and other pesticides causes conformational changes in the estrogen receptor. Before examining these factors, this work examines the protein unfolding from the antagonist form found in the 3ERT PDB crystal structure. The 3ERT PDB crystal structure has the estrogen receptor bound to the cancer drug 4-hydroxytamoxifen. The 4-hydroxytamoxifen ligand was extracted before the simulation, resulting in new conformational freedom due to absence of van der Waals contacts between the ligand and the receptor. The conformational changes that result expose the binding clef of the co peptide beside Helix 12 of the receptor forming an apo conformation. Two key conformations in the loops at either end of the H12 are produced resulting in the antagonist to apo conformation transformation. The results were produced over a 42ns Molecular Dynamics simulation using the AMBER FF99SB force field.

  2. A Practical Infrastructure for Real-Time Simulation across Timing Domains

    Directory of Open Access Journals (Sweden)

    Yao-fei Ma

    2015-01-01

    Full Text Available A real-time infrastructure, called MLRTI, is proposed in this paper to fulfill the requirement of real-time simulation in distributed environment. There are two novel contributions in this work. Firstly, a flexible timing mechanism is proposed to integrate external time source and local timer utility, enabling the distributed nodes to advance their timeline simultaneously at different speeds with high precision. A data transmission solution is also presented in which the reflective memory card (VMIC is employed to provide fast data transmission with minimum delay. Secondly, a system partition schema is proposed in MLRTI to reduce the solution errors introduced by transforming a continuous system into distribution system, which is common in a class of control applications where the system is designed in centralized model but simulated in distributed environment for constrains on system structure or the need to balance computation load. Experiments are conducted and the results show this schema effectively reduces the possible errors by properly partitioning the system into parts that are suitable to be deployed in distributed environment.

  3. Numerical simulation for thermohaline multiple equilibrant system in non-rectangular domains

    Institute of Scientific and Technical Information of China (English)

    詹杰民; 李毓湘

    2003-01-01

    In this paper, incompressible, double-diffusive convection is simulated using finite-difference schemes. The NavierStokes equations are expressed in terms of stream function and vorticity. Because of the existence of large velocity, temperature and salinity gradients in boundary layers, a boundary-fitted coordinate system is used to concentrate the grid points near the wall and fit complex boundaries. The finite-difference methods used include the high-order accurate upwind difference scheme. It is shown that the scheme is a good candidate for direct simulations of double-diffusive convection flows. The proposed method is first applied to symmetry breaking and overturning states in thermohalinedriven flows in trapezoid basins. The basic phenomena agree well with those by Dijkstra and Molemaker (1997 J. Fluid Mech. 331 169) and Quon and Ghil (1992 J. Fluid Mech. 245 449), but symmetry breaking and overturning states can occur in an asymmetric geometrical region without perturbations. Then the method is applied to double-diffusive convections in a cavity with opposing horizontal temperature and concentration gradients at large thermal (Rt), solutal (Rs) Rayleigh numbers and Lewis number. There are three straight sides and a sine curve side in the cavity. Basically,numerical results are in agreement with those of Lee and Hyun (1990 Int. J. Heat Mass Transfer 33 1619) qualitatively,but eddies mixing in the top left-hand corner near the curved wall affects the layered structure.

  4. Combining Public Domain and Professional Panoramic Imagery for the Accurate and Dense 3d Reconstruction of the Destroyed Bel Temple in Palmyra

    Science.gov (United States)

    Wahbeh, W.; Nebiker, S.; Fangi, G.

    2016-06-01

    This paper exploits the potential of dense multi-image 3d reconstruction of destroyed cultural heritage monuments by either using public domain touristic imagery only or by combining the public domain imagery with professional panoramic imagery. The focus of our work is placed on the reconstruction of the temple of Bel, one of the Syrian heritage monuments, which was destroyed in September 2015 by the so called "Islamic State". The great temple of Bel is considered as one of the most important religious buildings of the 1st century AD in the East with a unique design. The investigations and the reconstruction were carried out using two types of imagery. The first are freely available generic touristic photos collected from the web. The second are panoramic images captured in 2010 for documenting those monuments. In the paper we present a 3d reconstruction workflow for both types of imagery using state-of-the art dense image matching software, addressing the non-trivial challenges of combining uncalibrated public domain imagery with panoramic images with very wide base-lines. We subsequently investigate the aspects of accuracy and completeness obtainable from the public domain touristic images alone and from the combination with spherical panoramas. We furthermore discuss the challenges of co-registering the weakly connected 3d point cloud fragments resulting from the limited coverage of the touristic photos. We then describe an approach using spherical photogrammetry as a virtual topographic survey allowing the co-registration of a detailed and accurate single 3d model of the temple interior and exterior.

  5. THREE-DIMENSIONAL LARGE EDDY SIMULATION OF FREE SURFACE TURBULENT FLOW IN OPEN CHANNEL WITHIN SUBMERGED VEGETATION DOMAIN

    Institute of Scientific and Technical Information of China (English)

    Su Xiao-hui; Li C. W.; Chen Bi-hong

    2003-01-01

    A three-dimensional Large Eddy Simulation (LES) has been performed of hydrodynamic behavior of turbulent flow in open channel that the lower part of the domain is occupied by a drag force layer to represent vegetation.One equation model is used to closing the resolvable scale equations.The turbulent characteristic length is parameterized by a k-l model.A phenomenal model is employed to express the performance of vegetation in the open channel.The result reveals that the present model has the capacity of describing three-dimensional structure of large eddy appearing in turbulent flow in open channel with vegetation region and has the capacity of tracing the development of large eddies.

  6. Finite-Difference Time-Domain Simulation of Light Propagation in 2D Periodic and Quasi-Periodic Photonic Structures

    Directory of Open Access Journals (Sweden)

    N. Dadashzadeh

    2013-09-01

    Full Text Available Ultra-short pulse is a promising technology for achieving ultra-high data rate transmission which is required to follow the increased demand of data transport over an optical communication system. Therefore, the propagation of such type of pulses and the effects that it may suffer during its transmission through an optical waveguide has received a great deal of attention in the recent years. We provide an overview of recent theoretical developments in a numerical modeling of Maxwell's equations to analyze the propagation of short laser pulses in photonic structures. The process of short light pulse propagation through 2D periodic and quasi-periodic photonic structures is simulated based on Finite-Difference Time-Domain calculations of Maxwell’s equations.

  7. Simulating propagation of decoupled elastic waves using low-rank approximate mixed-domain integral operators for anisotropic media

    KAUST Repository

    Cheng, Jiubing

    2016-03-15

    In elastic imaging, the extrapolated vector fields are decoupled into pure wave modes, such that the imaging condition produces interpretable images. Conventionally, mode decoupling in anisotropic media is costly because the operators involved are dependent on the velocity, and thus they are not stationary. We have developed an efficient pseudospectral approach to directly extrapolate the decoupled elastic waves using low-rank approximate mixed-domain integral operators on the basis of the elastic displacement wave equation. We have applied k-space adjustment to the pseudospectral solution to allow for a relatively large extrapolation time step. The low-rank approximation was, thus, applied to the spectral operators that simultaneously extrapolate and decompose the elastic wavefields. Synthetic examples on transversely isotropic and orthorhombic models showed that our approach has the potential to efficiently and accurately simulate the propagations of the decoupled quasi-P and quasi-S modes as well as the total wavefields for elastic wave modeling, imaging, and inversion.

  8. An axisymmetric time-domain spectral-element method for full-wave simulations: Application to ocean acoustics

    CERN Document Server

    Bottero, Alexis; Komatitsch, Dimitri; Asch, Mark

    2016-01-01

    The numerical simulation of acoustic waves in complex 3D media is a key topic in many branches of science, from exploration geophysics to non-destructive testing and medical imaging. With the drastic increase in computing capabilities this field has dramatically grown in the last twenty years. However many 3D computations, especially at high frequency and/or long range, are still far beyond current reach and force researchers to resort to approximations, for example by working in 2D (plane strain) or by using a paraxial approximation. This article presents and validates a numerical technique based on an axisymmetric formulation of a spectral finite-element method in the time domain for heterogeneous fluid-solid media. Taking advantage of axisymmetry enables the study of relevant 3D configurations at a very moderate computational cost. The axisymmetric spectral-element formulation is first introduced, and validation tests are then performed. A typical application of interest in ocean acoustics showing upslope ...

  9. Finite volume - space-time discontinuous Galerkin method for the numerical simulation of compressible turbulent flow in time dependent domains

    Science.gov (United States)

    Česenek, Jan

    The article is concerned with the numerical simulation of the compressible turbulent flow in time dependent domains. The mathematical model of flow is represented by the system of non-stationary Reynolds- Averaged Navier-Stokes (RANS) equations. The motion of the domain occupied by the fluid is taken into account with the aid of the ALE (Arbitrary Lagrangian-Eulerian) formulation of the RANS equations. This RANS system is equipped with two-equation k - ω turbulence model. These two systems of equations are solved separately. Discretization of the RANS system is carried out by the space-time discontinuous Galerkin method which is based on piecewise polynomial discontinuous approximation of the sought solution in space and in time. Discretization of the two-equation k - ω turbulence model is carried out by the implicit finite volume method, which is based on piecewise constant approximation of the sought solution. We present some numerical experiments to demonstrate the applicability of the method using own-developed code.

  10. Finite-difference time-domain simulations of fabricated black silicon nanostructures: Optimal geometries for an antireflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, Adam [X-FAB Semiconductor Foundries AG, Erfurt (Germany); Technische Universitaet Ilmenau (Germany); Voerckel, Andreas [X-FAB Semiconductor Foundries AG, Erfurt (Germany)

    2010-07-01

    Nano-structured silicon has received a growing and serious amount of interest in industrial technology and university research, particularly in regard to the possibility of such nanostructures in optics, with the primary interest here being black silicon as an anti-reflective coating (ARC) for photodiodes. Current literature now contains a wealth of morphological information to influence structure growth and shape in fluorine-based plasma etching in the presence of oxide-forming or fluorocarbon gas inhibitors. Using the computationally efficient grid-based differential time-domain numerical modeling of the finite-difference time-domain (FDTD) method, approximations to Maxwell's equations are solved to model the optical properties of crystalline black silicon. Multiple geometries, from pillars to more pyramid and needle-like structures, are considered and results are correlated to actual scanning electron microscope (SEM) pictures with corresponding reflection measurements taken in a Cary 5000 UV*VIS spectrophotometer with accompanying integrating (Ulbricht) sphere from 200 nm to 800 nm to evaluate both diffuse and specular reflection from the silicon surface. Optimal geometries are simulated and the consequences for photodiode applications are discussed.

  11. Integrating NASA's Land Analysis System (LAS) image processing software with an appropriate Geographic Information System (GIS): A review of candidates in the public domain

    Science.gov (United States)

    Rochon, Gilbert L.

    1989-01-01

    A user requirements analysis (URA) was undertaken to determine and appropriate public domain Geographic Information System (GIS) software package for potential integration with NASA's LAS (Land Analysis System) 5.0 image processing system. The necessity for a public domain system was underscored due to the perceived need for source code access and flexibility in tailoring the GIS system to the needs of a heterogenous group of end-users, and to specific constraints imposed by LAS and its user interface, Transportable Applications Executive (TAE). Subsequently, a review was conducted of a variety of public domain GIS candidates, including GRASS 3.0, MOSS, IEMIS, and two university-based packages, IDRISI and KBGIS. The review method was a modified version of the GIS evaluation process, development by the Federal Interagency Coordinating Committee on Digital Cartography. One IEMIS-derivative product, the ALBE (AirLand Battlefield Environment) GIS, emerged as the most promising candidate for integration with LAS. IEMIS (Integrated Emergency Management Information System) was developed by the Federal Emergency Management Agency (FEMA). ALBE GIS is currently under development at the Pacific Northwest Laboratory under contract with the U.S. Army Corps of Engineers' Engineering Topographic Laboratory (ETL). Accordingly, recommendations are offered with respect to a potential LAS/ALBE GIS linkage and with respect to further system enhancements, including coordination with the development of the Spatial Analysis and Modeling System (SAMS) GIS in Goddard's IDM (Intelligent Data Management) developments in Goddard's National Space Science Data Center.

  12. Validation of frequency and mode extraction calculations from time-domain simulations of accelerator cavities

    CERN Document Server

    Austin, T M; Ovtchinnikov, S; Werner, G R; Bellantoni, L

    2010-01-01

    The recently developed frequency extraction algorithm [G.R. Werner and J.R. Cary, J. Comp. Phys. 227, 5200 (2008)] that enables a simple FDTD algorithm to be transformed into an efficient eigenmode solver is applied to a realistic accelerator cavity modeled with embedded boundaries and Richardson extrapolation. Previously, the frequency extraction method was shown to be capable of distinguishing M degenerate modes by running M different simulations and to permit mode extraction with minimal post-processing effort that only requires solving a small eigenvalue problem. Realistic calculations for an accelerator cavity are presented in this work to establish the validity of the method for realistic modeling scenarios and to illustrate the complexities of the computational validation process. The method is found to be able to extract the frequencies with error that is less than a part in 10^5. The corrected experimental and computed values differ by about one parts in 10^$, which is accounted for (in largest part)...

  13. Escitalopram prolonged fear induced by simulated public speaking and released hypothalamic-pituitary-adrenal axis activation.

    Science.gov (United States)

    Garcia-Leal, C; Del-Ben, C M; Leal, F M; Graeff, F G; Guimarães, F S

    2010-05-01

    Simulated public speaking (SPS) test is sensitive to drugs that interfere with serotonin-mediated neurotransmission and is supposed to recruit neural systems involved in panic disorder. The study was aimed at evaluating the effects of escitalopram, the most selective serotonin-selective reuptake inhibitor available, in SPS. Healthy males received, in a double-blind, randomized design, placebo (n = 12), 10 (n = 17) or 20 (n = 14) mg of escitalopram 2 hours before the test. Behavioural, autonomic and neuroendocrine measures were assessed. Both doses of escitalopram did not produce any effect before or during the speech but prolonged the fear induced by SPS. The test itself did not significantly change cortisol and prolactin levels but under the higher dose of escitalopram, cortisol and prolactin increased immediately after SPS. This fear-enhancing effect of escitalopram agrees with previously reported results with less selective serotonin reuptake inhibitors and the receptor antagonist ritanserin, indicating that serotonin inhibits the fear of speaking in public.

  14. Insight into the adsorption profiles of the Saprolegnia monoica chitin synthase MIT domain on POPA and POPC membranes by molecular dynamics simulation studies.

    Science.gov (United States)

    Kuang, Guanglin; Liang, Lijun; Brown, Christian; Wang, Qi; Bulone, Vincent; Tu, Yaoquan

    2016-02-21

    The critical role of chitin synthases in oomycete hyphal tip growth has been established. A microtubule interacting and trafficking (MIT) domain was discovered in the chitin synthases of the oomycete model organism, Saprolegnia monoica. MIT domains have been identified in diverse proteins and may play a role in intracellular trafficking. The structure of the Saprolegnia monoica chitin synthase 1 (SmChs1) MIT domain has been recently determined by our group. However, although our in vitro assay identified increased strength in interactions between the MIT domain and phosphatidic acid (PA) relative to other phospholipids including phosphatidylcholine (PC), the mechanism used by the MIT domain remains unknown. In this work, the adsorption behavior of the SmChs1 MIT domain on POPA and POPC membranes was systematically investigated by molecular dynamics simulations. Our results indicate that the MIT domain can adsorb onto the tested membranes in varying orientations. Interestingly, due to the specific interactions between MIT residues and lipid molecules, the binding affinity to the POPA membrane is much higher than that to the POPC membrane. A binding hotspot, which is critical for the adsorption of the MIT domain onto the POPA membrane, was also identified. The lower binding affinity to the POPC membrane can be attributed to the self-saturated membrane surface, which is unfavorable for hydrogen-bond and electrostatic interactions. The present study provides insight into the adsorption profile of SmChs1 and additionally has the potential to improve our understanding of other proteins containing MIT domains.

  15. Stress Domains in Si(111)/a-Si{sub 3}N{sub 4} Nanopixel: Ten-Million-Atom Molecular Dynamics Simulations on Parallel Computers

    Energy Technology Data Exchange (ETDEWEB)

    Omeltchenko, Andrey; Bachlechner, Martina E.; Nakano, Aiichiro; Kalia, Rajiv K.; Vashishta, Priya; Ebbsjoe, Ingvar; Madhukar, Anupam; Messina, Paul

    2000-01-10

    Parallel molecular dynamics simulations are performed to determine atomic-level stresses in Si(111)/Si {sub 3}N{sub 4}(0001) and Si(111)/a-Si {sub 3}N{sub 4} nanopixels. Compared to the crystalline case, the stresses in amorphous Si{sub 3}N {sub 4} are highly inhomogeneous in the plane of the interface. In silicon below the interface, for a 25 nm square mesa stress domains with triangular symmetry are observed, whereas for a rectangular, 54 nmx33 nm , mesa tensile stress domains ({approx}300 Angstrom) are separated by Y-shaped compressive domain wall. Maximum stresses in the domains and domain walls are -2 GPa and +2 GPa , respectively. (c) 2000 The American Physical Society.

  16. Transient Stability Analysis of Grid-connected Wind Turbines with Time Domain Simulation

    Directory of Open Access Journals (Sweden)

    Shuaibing Li

    2013-07-01

    Full Text Available With an ever-increasing pentration of wind power into power system, the influence to overall system behavior and stability becomes obviously. Therefore, it is so necessary to require wind turbines have good grid adaptability. This paper investigates the effect of directly grid-connected front-end speed controlled wind turbines (FSCWT on transient stability of power system.For this purpose, a voltage based synchronous generator model is used and the drive train model with WinDriver is built. By using a fast excitation control of FSCWT exciter, the FSCWT wind turbines can successfully ride through grid fault and have no problem of angular stability when connected to grid. Simulation studies are carried out to demonstrate and compare the transient performance of the IEEE 5-machine 14-bus system with FSCWT replace by double fed induction generators (DFIG during a three phase fault. Results show that a better transient stability performance is achieved with an intergration of FSCWT in comparsion with DFIG, which can even bring some benefits on power system transient performance and stability.

  17. High-performance finite-difference time-domain simulations of C-Mod and ITER RF antennas

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Thomas G., E-mail: tgjenkins@txcorp.com; Smithe, David N., E-mail: smithe@txcorp.com [Tech-X Corporation, 5621 Arapahoe Avenue Suite A, Boulder, CO 80303 (United States)

    2015-12-10

    Finite-difference time-domain methods have, in recent years, developed powerful capabilities for modeling realistic ICRF behavior in fusion plasmas [1, 2, 3, 4]. When coupled with the power of modern high-performance computing platforms, such techniques allow the behavior of antenna near and far fields, and the flow of RF power, to be studied in realistic experimental scenarios at previously inaccessible levels of resolution. In this talk, we present results and 3D animations from high-performance FDTD simulations on the Titan Cray XK7 supercomputer, modeling both Alcator C-Mod’s field-aligned ICRF antenna and the ITER antenna module. Much of this work focuses on scans over edge density, and tailored edge density profiles, to study dispersion and the physics of slow wave excitation in the immediate vicinity of the antenna hardware and SOL. An understanding of the role of the lower-hybrid resonance in low-density scenarios is emerging, and possible implications of this for the NSTX launcher and power balance are also discussed. In addition, we discuss ongoing work centered on using these simulations to estimate sputtering and impurity production, as driven by the self-consistent sheath potentials at antenna surfaces.

  18. Investigating the spectral characteristics of backscattering from heterogeneous spheroidal nuclei using broadband finite-difference time-domain simulations

    Science.gov (United States)

    Chao, Guo-Shan; Sung, Kung-Bin

    2010-02-01

    Backscattered light spectra have been used to extract size distribution of cell nuclei in epithelial tissues for noninvasive detection of precancerous lesions. In existing experimental studies, size estimation is achieved by assuming nuclei as homogeneous spheres or spheroids and fitting the measured data with models based on Mie theory. However, the validity of simplifying nuclei as homogeneous spheres has not been thoroughly examined. In this study, we investigate the spectral characteristics of backscattering from models of spheroidal nuclei under plane wave illumination using three-dimensional finite-difference time-domain (FDTD) simulation. A modulated Gaussian pulse is used to obtain wavelength dependent scattering intensity with a single FDTD run. The simulated model of nuclei consists of a nucleolus and randomly distributed chromatin condensation in homogeneous cytoplasm and nucleoplasm. The results show that backscattering spectra from spheroidal nuclei have similar oscillating patterns to those from homogeneous spheres with the diameter equal to the projective length of the spheroidal nucleus along the propagation direction. The strength of backscattering is enhanced in heterogeneous spheroids as compared to homogeneous spheroids. The degree of which backscattering spectra of heterogeneous nuclei deviate from Mie theory is highly dependent on the distribution of chromatin/nucleolus but not sensitive to nucleolar size, refractive index fluctuation or chromatin density.

  19. Molecular Dynamics Simulations of Voltage Gated Cation Channels: Insights on Voltage-Sensor Domain Function and Modulation

    Directory of Open Access Journals (Sweden)

    Lucie eDelemotte

    2012-05-01

    Full Text Available Since their discovery in the 1950s, the structure and function of voltage gated cation channels (VGCC has been largely understood thanks to results stemming from electrophysiology, pharmacology, spectroscopy and structural biology. Over the past decade, computational methods such as molecular dynamics (MD simulations have also contributed, providing molecular level information that can be tested against experimental results, thereby allowing the validation of the models and protocols. Importantly, MD can shed light on elements of VGCC function that cannot be easily accessed through classical experiments. Here, we review the results of recent MD simulations addressing key questions that pertain to the function and modulation of the VGCC’s voltage sensor domain (VSD highlighting: 1 the movement of the S4-helix basic residues during channel activation, articulating how the electrical driving force acts upon them; 2 the nature of the VSD intermediate states on transitioning between open and closed states of the VGCC; and 3 the molecular level effects on the VSD arising from mutations of specific S4 positively charged residues involved in certain genetic diseases.

  20. FluTE, a publicly available stochastic influenza epidemic simulation model.

    Directory of Open Access Journals (Sweden)

    Dennis L Chao

    2010-01-01

    Full Text Available Mathematical and computer models of epidemics have contributed to our understanding of the spread of infectious disease and the measures needed to contain or mitigate them. To help prepare for future influenza seasonal epidemics or pandemics, we developed a new stochastic model of the spread of influenza across a large population. Individuals in this model have realistic social contact networks, and transmission and infections are based on the current state of knowledge of the natural history of influenza. The model has been calibrated so that outcomes are consistent with the 1957/1958 Asian A(H2N2 and 2009 pandemic A(H1N1 influenza viruses. We present examples of how this model can be used to study the dynamics of influenza epidemics in the United States and simulate how to mitigate or delay them using pharmaceutical interventions and social distancing measures. Computer simulation models play an essential role in informing public policy and evaluating pandemic preparedness plans. We have made the source code of this model publicly available to encourage its use and further development.

  1. The EAGLE simulations of galaxy formation: Public release of halo and galaxy catalogues

    Science.gov (United States)

    McAlpine, S.; Helly, J. C.; Schaller, M.; Trayford, J. W.; Qu, Y.; Furlong, M.; Bower, R. G.; Crain, R. A.; Schaye, J.; Theuns, T.; Dalla Vecchia, C.; Frenk, C. S.; McCarthy, I. G.; Jenkins, A.; Rosas-Guevara, Y.; White, S. D. M.; Baes, M.; Camps, P.; Lemson, G.

    2016-04-01

    We present the public data release of halo and galaxy catalogues extracted from the EAGLE suite of cosmological hydrodynamical simulations of galaxy formation. These simulations were performed with an enhanced version of the GADGET code that includes a modified hydrodynamics solver, time-step limiter and subgrid treatments of baryonic physics, such as stellar mass loss, element-by-element radiative cooling, star formation and feedback from star formation and black hole accretion. The simulation suite includes runs performed in volumes ranging from 25 to 100 comoving megaparsecs per side, with numerical resolution chosen to marginally resolve the Jeans mass of the gas at the star formation threshold. The free parameters of the subgrid models for feedback are calibrated to the redshift z = 0 galaxy stellar mass function, galaxy sizes and black hole mass-stellar mass relation. The simulations have been shown to match a wide range of observations for present-day and higher-redshift galaxies. The raw particle data have been used to link galaxies across redshifts by creating merger trees. The indexing of the tree produces a simple way to connect a galaxy at one redshift to its progenitors at higher redshift and to identify its descendants at lower redshift. In this paper we present a relational database which we are making available for general use. A large number of properties of haloes and galaxies and their merger trees are stored in the database, including stellar masses, star formation rates, metallicities, photometric measurements and mock gri images. Complex queries can be created to explore the evolution of more than 105 galaxies, examples of which are provided in the Appendix. The relatively good and broad agreement of the simulations with a wide range of observational datasets makes the database an ideal resource for the analysis of model galaxies through time, and for connecting and interpreting observational datasets.

  2. Use of Web 2.0 Technologies for Public Outreach on a Simulated Mars Mission

    Science.gov (United States)

    Shiro, B.; Palaia, J.; Ferrone, K.

    2009-12-01

    Recent advances in social media and internet communications have revolutionized the ways people interact and disseminate information. Astronauts are already starting to take advantage of these tools by blogging and tweeting from space, and almost all NASA missions now have presences on the major social networking sites. One priority for future human explorers on Mars will be communicating their experiences to the people back on Earth. During July 2009, a six-member crew of volunteers carried out a simulated Mars mission at the Flashline Mars Arctic Research Station (FMARS) on Devon Island in the Canadian Arctic. Living in a habitat, conducting EVAs wearing spacesuits, and observing communication delays with “Earth,” the crew endured restrictions similar to those that will be faced by future human Mars explorers. Throughout the expedition, crewmembers posted regular blog entries, reports, photos, videos, and updates to their website and social media outlets Twitter, Facebook, YouTube, and Picasa Web Albums. During the sixteen EVAs of their field science research campaign, FMARS crewmembers collected GPS track information and took geotagged photos using GPS-enabled cameras. They combined their traverse GPS tracks with photo location information into KML/KMZ files that website visitors can view in Google Maps or Google Earth. Although the crew observed a strict 20-minute communication delay with “Earth” to simulate a real Mars mission, they broke this rule to conduct four very successful live webcasts with student groups using Skype since education and public outreach were important objectives of the endeavor. This presentation will highlight the use of Web 2.0 technologies for public outreach during the simulated Mars expedition and the implications for other remote scientific journeys. The author embarks on a "rover" to carry out an EVA near the FMARS Habitat. The satellite dish to the right of the structure was used for all communications with the remote

  3. Insights into the folding and unfolding processes of wild-type and mutated SH3 domain by molecular dynamics and replica exchange molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Wen-Ting Chu

    Full Text Available Src-homology regions 3 (SH3 domain is essential for the down-regulation of tyrosine kinase activity. Mutation A39V/N53P/V55L of SH3 is found to be relative to the urgent misfolding diseases. To gain insight, the human and gallus SH3 domains (PDB ID: 1NYG and 2LP5, including 58 amino acids in each protein, were selected for MD simulations (Amber11, ff99SB force field and cluster analysis to investigate the influence of mutations on the spatial structure of the SH3 domain. It is found that the large conformational change of mutations mainly exists in three areas in the vicinity of protein core: RT loop, N-src loop, distal β-hairpin to 310 helix. The C-terminus of the mutated gallus SH3 is disordered after simulation, which represents the intermediate state of aggregation. The disappeared strong Hbond net in the mutated human and gallus systems will make these mutated proteins looser than the wild-type proteins. Additionally, by performing the REMD simulations on the gallus SH3 domain, the mutated domain is found to have an obvious effect on the unfolding process. These studies will be helpful for further aggregation mechanisms investigations on SH3 family.

  4. Understanding and simulating the link between African easterly waves and Atlantic tropical cyclones using a regional climate model: the role of domain size and lateral boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Caron, Louis-Philippe [MISU, Stockholm University, Stockholm (Sweden); Universite du Quebec a Montreal, CRCMD Network, Montreal, QC (Canada); Jones, Colin G. [Swedish Meterological and Hydrological Institute, Rossby Center, Norrkoeping (Sweden)

    2012-07-15

    Using a suite of lateral boundary conditions, we investigate the impact of domain size and boundary conditions on the Atlantic tropical cyclone and african easterly Wave activity simulated by a regional climate model. Irrespective of boundary conditions, simulations closest to observed climatology are obtained using a domain covering both the entire tropical Atlantic and northern African region. There is a clear degradation when the high-resolution model domain is diminished to cover only part of the African continent or only the tropical Atlantic. This is found to be the result of biases in the boundary data, which for the smaller domains, have a large impact on TC activity. In this series of simulations, the large-scale Atlantic atmospheric environment appears to be the primary control on simulated TC activity. Weaker wave activity is usually accompanied by a shift in cyclogenesis location, from the MDR to the subtropics. All ERA40-driven integrations manage to capture the observed interannual variability and to reproduce most of the upward trend in tropical cyclone activity observed during that period. When driven by low-resolution global climate model (GCM) integrations, the regional climate model captures interannual variability (albeit with lower correlation coefficients) only if tropical cyclones form in sufficient numbers in the main development region. However, all GCM-driven integrations fail to capture the upward trend in Atlantic tropical cyclone activity. In most integrations, variations in Atlantic tropical cyclone activity appear uncorrelated with variations in African easterly wave activity. (orig.)

  5. Perfectly matched layer stability in 3-D finite-difference time-domain simulation of electroacoustic wave propagation in piezoelectric crystals with different symmetry class.

    Science.gov (United States)

    Nova, Omar; Peña, Néstor; Ney, Michel

    2015-03-01

    Perfectly matched layer stability in 3-D finite-difference time-domain simulations is demonstrated for two piezoelectric crystals: barium sodium niobate and bismuth germanate. Stability is achieved by adapting the discretization grid to meet a central-difference scheme. Stability is demonstrated by showing that the total energy of the piezoelectric system remains constant in the steady state.

  6. An axisymmetric time-domain spectral-element method for full-wave simulations: Application to ocean acoustics

    Science.gov (United States)

    Bottero, Alexis; Cristini, Paul; Komatitsch, Dimitri; Asch, Mark

    2016-11-01

    The numerical simulation of acoustic waves in complex 3D media is a key topic in many branches of science, from exploration geophysics to non-destructive testing and medical imaging. With the drastic increase in computing capabilities this field has dramatically grown in the last twenty years. However many 3D computations, especially at high frequency and/or long range, are still far beyond current reach and force researchers to resort to approximations, for example by working in 2D (plane strain) or by using a paraxial approximation. This article presents and validates a numerical technique based on an axisymmetric formulation of a spectral finite-element method in the time domain for heterogeneous fluid-solid media. Taking advantage of axisymmetry enables the study of relevant 3D configurations at a very moderate computational cost. The axisymmetric spectral-element formulation is first introduced, and validation tests are then performed. A typical application of interest in ocean acoustics showing upslope propagation above a dipping viscoelastic ocean bottom is then presented. The method correctly models backscattered waves and explains the transmission losses discrepancies pointed out in Jensen et al. (2007). Finally, a realistic application to a double seamount problem is considered.

  7. Investigating the spectral characteristics of backscattering from heterogeneous spherical nuclei using broadband finite-difference time-domain simulations

    Science.gov (United States)

    Chao, Guo-Shan; Sung, Kung-Bin

    2010-01-01

    Reflectance spectra measured from epithelial tissue have been used to extract size distribution and refractive index of cell nuclei for noninvasive detection of precancerous changes. Despite many in vitro and in vivo experimental results, the underlying mechanism of sizing nuclei based on modeling nuclei as homogeneous spheres and fitting the measured data with Mie theory has not been fully explored. We describe the implementation of a three-dimensional finite-difference time-domain (FDTD) simulation tool using a Gaussian pulse as the light source to investigate the wavelength-dependent characteristics of backscattered light from a nuclear model consisting of a nucleolus and clumps of chromatin embedded in homogeneous nucleoplasm. The results show that small-sized heterogeneities within the nuclei generate about five times higher backscattering than homogeneous spheres. More interestingly, backscattering spectra from heterogeneous spherical nuclei show periodic oscillations similar to those from homogeneous spheres, leading to high accuracy of estimating the nuclear diameter by comparison with Mie theory. In addition to the application in light scattering spectroscopy, the reported FDTD method could be adapted to study the relations between measured spectral data and nuclear structures in other optical imaging and spectroscopic techniques for in vivo diagnosis.

  8. Field Measurements and Numerical Simulations of Temperature and Moisture in Highway Engineering Using a Frequency Domain Reflectometry Sensor.

    Science.gov (United States)

    Yao, Yong-Sheng; Zheng, Jian-Long; Chen, Zeng-Shun; Zhang, Jun-Hui; Li, Yong

    2016-06-10

    This paper presents a systematic pioneering study on the use of agricultural-purpose frequency domain reflectometry (FDR) sensors to monitor temperature and moisture of a subgrade in highway extension and reconstruction engineering. The principle of agricultural-purpose FDR sensors and the process for embedding this kind of sensors for subgrade engineering purposes are introduced. Based on field measured weather data, a numerical analysis model for temperature and moisture content in the subgrade's soil is built. Comparisons of the temperature and moisture data obtained from numerical simulation and FDR-based measurements are conducted. The results show that: (1) the embedding method and process, data acquisition, and remote transmission presented are reasonable; (2) the temperature and moisture changes are coordinated with the atmospheric environment and they are also in close agreement with numerical calculations; (3) the change laws of both are consistent at positions where the subgrade is compacted uniformly. These results suggest that the data measured by the agricultural-purpose FDR sensors are reliable. The findings of this paper enable a new and effective real-time monitoring method for a subgrade's temperature and moisture changes, and thus broaden the application of agricultural-purpose FDR sensors.

  9. Field Measurements and Numerical Simulations of Temperature and Moisture in Highway Engineering Using a Frequency Domain Reflectometry Sensor

    Directory of Open Access Journals (Sweden)

    Yong-Sheng Yao

    2016-06-01

    Full Text Available This paper presents a systematic pioneering study on the use of agricultural-purpose frequency domain reflectometry (FDR sensors to monitor temperature and moisture of a subgrade in highway extension and reconstruction engineering. The principle of agricultural-purpose FDR sensors and the process for embedding this kind of sensors for subgrade engineering purposes are introduced. Based on field measured weather data, a numerical analysis model for temperature and moisture content in the subgrade’s soil is built. Comparisons of the temperature and moisture data obtained from numerical simulation and FDR-based measurements are conducted. The results show that: (1 the embedding method and process, data acquisition, and remote transmission presented are reasonable; (2 the temperature and moisture changes are coordinated with the atmospheric environment and they are also in close agreement with numerical calculations; (3 the change laws of both are consistent at positions where the subgrade is compacted uniformly. These results suggest that the data measured by the agricultural-purpose FDR sensors are reliable. The findings of this paper enable a new and effective real-time monitoring method for a subgrade’s temperature and moisture changes, and thus broaden the application of agricultural-purpose FDR sensors.

  10. Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations

    Energy Technology Data Exchange (ETDEWEB)

    Rees, M. [Aerodyn Energiesysteme gmbH, Rendsburg (Germany)

    1996-09-01

    The Germanische Lloyd guideline allows calculations of load spectra in two fundamentally different ways. In the case of the so-called `simplified load spectra` the maximum amplitude of fluctuation of a load component is formed as {+-}75% of the average value of the purely aerodynamic loads of this component at rated wind conditions, together with an overlay of mass-related loads. The second method allowed in the GL guideline is the calculation of load spectra from simulation results in the time domain. For a number of average wind speeds the time-dependent characteristics of the load components are calculated taking account of the natural spatial turbulence of the wind. These are converted into load spectra using the rainflow method. In a parametric study the load spectra are calculated according to both methods and compared. The calculations are performed for turbines with rated powers of 100 kW to 2000 kW, with two and three blades, and also for stall-controlled and pitch-controlled turbines. The calculated load spectra are compared with each by means of 1 P fatigue equivalent load spectra. The influence of individual parameters is presented, as is the validity of the simplified load spectra. (au)

  11. Rimonabant effects on anxiety induced by simulated public speaking in healthy humans: a preliminary report.

    Science.gov (United States)

    Bergamaschi, Mateus M; Queiroz, Regina H C; Chagas, Marcos H N; Linares, Ila M P; Arrais, Kátia C; de Oliveira, Danielle C G; Queiroz, Maria E; Nardi, Antonio E; Huestis, Marilyn A; Hallak, Jaime E C; Zuardi, Antonio W; Moreira, Fabrício A; Crippa, José A S

    2014-01-01

    We investigated the hypothesis that rimonabant, a cannabinoid antagonist/inverse agonist, would increase anxiety in healthy subjects during a simulation of the public speaking test. Participants were randomly allocated to receive oral placebo or 90 mg rimonabant in a double-blind design. Subjective effects were measured by Visual Analogue Mood Scale. Physiological parameters, namely arterial blood pressure and heart rate, also were monitored. Twelve participants received oral placebo and 12 received 90 mg rimonabant. Rimonabant increased self-reported anxiety levels during the anticipatory speech and performance phase compared with placebo. Interestingly, rimonabant did not modulate anxiety prestress and was not associated with sedation, cognitive impairment, discomfort, or blood pressure changes. Cannabinoid-1 antagonism magnifies the responses to an anxiogenic stimulus without interfering with the prestress phase. These data suggest that the endocannabinoid system may work on-demand to counteract the consequences of anxiogenic stimuli in healthy humans. Copyright © 2013 John Wiley & Sons, Ltd.

  12. Sensitivity studies of high-resolution RegCM3 simulations of precipitation over the European Alps: the effect of lateral boundary conditions and domain size

    Science.gov (United States)

    Nadeem, Imran; Formayer, Herbert

    2016-11-01

    A suite of high-resolution (10 km) simulations were performed with the International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3) to study the effect of various lateral boundary conditions (LBCs), domain size, and intermediate domains on simulated precipitation over the Great Alpine Region. The boundary conditions used were ECMWF ERA-Interim Reanalysis with grid spacing 0.75∘, the ECMWF ERA-40 Reanalysis with grid spacing 1.125 and 2.5∘, and finally the 2.5∘ NCEP/DOE AMIP-II Reanalysis. The model was run in one-way nesting mode with direct nesting of the high-resolution RCM (horizontal grid spacing Δx = 10 km) with driving reanalysis, with one intermediate resolution nest (Δx = 30 km) between high-resolution RCM and reanalysis forcings, and also with two intermediate resolution nests (Δx = 90 km and Δx = 30 km) for simulations forced with LBC of resolution 2.5∘. Additionally, the impact of domain size was investigated. The results of multiple simulations were evaluated using different analysis techniques, e.g., Taylor diagram and a newly defined useful statistical parameter, called Skill-Score, for evaluation of daily precipitation simulated by the model. It has been found that domain size has the major impact on the results, while different resolution and versions of LBCs, e.g., 1.125∘ ERA40 and 0.7∘ ERA-Interim, do not produce significantly different results. It is also noticed that direct nesting with reasonable domain size, seems to be the most adequate method for reproducing precipitation over complex terrain, while introducing intermediate resolution nests seems to deteriorate the results.

  13. Anxiolytic-like effect of oxytocin in the simulated public speaking test.

    Science.gov (United States)

    de Oliveira, Danielle C G; Zuardi, Antonio W; Graeff, Frederico G; Queiroz, Regina H C; Crippa, José A S

    2012-04-01

    Oxytocin (OT) is known to be involved in anxiety, as well as cardiovascular and hormonal regulation. The objective of this study was to assess the acute effect of intranasally administered OT on subjective states, as well as cardiovascular and endocrine parameters, in healthy volunteers (n = 14) performing a simulated public speaking test. OT or placebo was administered intranasally 50 min before the test. Assessments were made across time during the experimental session: (1) baseline (-30 min); (2) pre-test (-15 min); (3) anticipation of the speech (50 min); (4) during the speech (1:03 h), post-test time 1 (1:26 h), and post-test time 2 (1:46 h). Subjective states were evaluated by self-assessment scales. Cortisol serum and plasma adrenocorticotropic hormone (ACTH) were measured. Additionally, heart rate, blood pressure, skin conductance, and the number of spontaneous fluctuations in skin conductance were measured. Compared with placebo, OT reduced the Visual Analogue Mood Scale (VAMS) anxiety index during the pre-test phase only, while increasing sedation at the pre-test, anticipation, and speech phases. OT also lowered the skin conductance level at the pre-test, anticipation, speech, and post-test 2 phases. Other parameters evaluated were not significantly affected by OT. The present results show that OT reduces anticipatory anxiety, but does not affect public speaking fear, suggesting that this hormone has anxiolytic properties.

  14. Probing the interaction between cHAVc3 peptide and the EC1 domain of E-cadherin using NMR and molecular dynamics simulations.

    Science.gov (United States)

    Alaofi, Ahmed; Farokhi, Elinaz; Prasasty, Vivitri D; Anbanandam, Asokan; Kuczera, Krzysztof; Siahaan, Teruna J

    2017-01-01

    The goal of this work is to probe the interaction between cyclic cHAVc3 peptide and the EC1 domain of human E-cadherin protein. Cyclic cHAVc3 peptide (cyclo(1,6)Ac-CSHAVC-NH2) binds to the EC1 domain as shown by chemical shift perturbations in the 2D (1)H,-(15)N-HSQC NMR spectrum. The molecular dynamics (MD) simulations of the EC1 domain showed folding of the C-terminal tail region into the main head region of the EC1 domain. For cHAVc3 peptide, replica exchange molecular dynamics (REMD) simulations generated five structural clusters of cHAVc3 peptide. Representative structures of cHAVc3 and the EC1 structure from MD simulations were used in molecular docking experiments with NMR constraints to determine the binding site of the peptide on EC1. The results suggest that cHAVc3 binds to EC1 around residues Y36, S37, I38, I53, F77, S78, H79, and I94. The dissociation constants (Kd values) of cHAVc3 peptide to EC1 were estimated using the NMR chemical shifts data and the estimated Kds are in the range of .5 × 10(-5)-7.0 × 10(-5) M.

  15. 报刊公共领域与邹韬奋%The public domain of newspaper and journal and Zou Taofen

    Institute of Scientific and Technical Information of China (English)

    董亚秋

    2012-01-01

      众所周知,邹韬奋是我国卓越的新闻记者、出版家,更是一名进步爱国的政论家。他主编的《生活》周刊、《大众生活》和《全民抗战》刊物,由于其客观的立场、报刊的公共性和其注重与读者平等的讨论,构成了报刊公共领域。作为这一公共领域中的发言人角色,邹韬奋积极发表新闻评论,设立读者信箱和小言论等精品栏目,与读者和同仁进行交流。这些编辑出版活动充分展现了邹韬奋在报刊公共空间中的舆论引导作用。%  As we all know, Zou Tao-fen is an excellent journalist, publishing house, was a progressive patriotic political commentators. He published in life magazine, the public and the National Journal of the war, due to its objective of publicity and its focus on position, press and reader discussions on an equal footing, forming the newspaper of the public domain. Role as spokesman in this public area, Zou Tao-fen news positive comments, set up reader mail and small boutique, such as columns, communicate with colleagues and readers. These activities have fully demonstrated Zou taofen's editing and publishing in the newspaper public opinion to guide the role of the public space.

  16. Analysis of Macro-micro Simulation Models for Service-Oriented Public Platform: Coordination of Networked Services and Measurement of Public Values

    Science.gov (United States)

    Kinoshita, Yumiko

    When service sectors are a major driver for the growth of the world economy, we are challenged to implement service-oriented infrastructure as e-Gov platform to achieve further growth and innovation for both developed and developing countries. According to recent trends in service industry, it is clarified that main factors for the growth of service sectors are investment into knowledge, trade, and the enhanced capacity of micro, small, and medium-sized enterprises (MSMEs). In addition, the design and deployment of public service platform require appropriate evaluation methodology. Reflecting these observations, this paper proposes macro-micro simulation approach to assess public values (PV) focusing on MSMEs. Linkage aggregate variables (LAVs) are defined to show connection between macro and micro impacts of public services. As a result, the relationship of demography, business environment, macro economy, and socio-economic impact are clarified and their values are quantified from the behavioral perspectives of citizens and firms.

  17. The sailor, the turtle and the jungle man - striking the balance between protection and public domain in fictional character merchandising

    OpenAIRE

    Preiss LL.M., Sven

    2013-01-01

    What is it that ‘Popeye the Sailor’, the ‘Teenage Mutant Hero Turtles’ and ‘Tarzan’ have in common? Besides being well-known fictitious characters, each of them is overwhelmingly successful in terms of entertainment (for the public) and revenue (for the industry behind it). They exemplify the possibility of the fictional characters’ owners not only using them for their basic purpose, i.e. in books, comics, movies, broadcasts, etc., but also of secondary exploitation of the characters’ gained ...

  18. Use of Web 2.0 Technologies for Public Outreach on a Simulated Mars Mission

    Science.gov (United States)

    Ferrone, Kristine; Shiro, Brian; Palaia, Joseph E., IV

    2009-01-01

    Recent advances in social media and internet communications have revolutionized the ways people interact and disseminate information. Astronauts are already taking advantage of these tools by blogging and tweeting from space, and almost all NASA missions now have presences on the major social networking sites. One priotity for future human explorers on Mars will be communicating their experiences to the people back on Earth. During July 2009, a 6-member crew of volunteers carried out a simulated Mars mission at the Flashline Mars Arctic Research Station (FMARS). The Mars Society built the mock Mars habitat in 2000-01 to help develop key knowledge and inspire the public for human Mars exploration. It is located on Devon island about 1600 km from the North Pole within the Arctic Circle. The structure is situated on the rim of Haughton Crater in an environment geologically and biologically analogous to Mars. Living in a habitat, conducting EVAs wearing spacesuits, and observing communication delays with "Earth,"the crew endured restrictions similar to those that will be faced by future human Mars explorers. Throughout the expedition, crewmembers posted daily blog entries, reports, photos, videos, and updates to their website and social media outlets Twitter, Facebook, YouTube, and Picasa Web Albums. During the sixteen EVAs of thier field science research campaign, FMARS crewmembers collected GPS track information and took geotagged photos using GPS-enabled cameras. They combined their traverse GPS tracks with photo location information into KML/KMZ files that website visitors can view in Google Earth.

  19. Multi-domain simulation of transient junction temperatures and resulting stress-strain behavior of power switches for long-term mission profiles

    Energy Technology Data Exchange (ETDEWEB)

    Drofenik, U.; Kovacevic, I.; Kolar, J. W. [Swiss Federal Institute of Technology, Power Electronic Systems Laboratory, Zuerich (Switzerland); Schmidt, R. [ABB Switzerland Ltd., Corporate Research, Baden-Daettwil (Switzerland)

    2008-07-01

    For lifetime estimation of power converters in traction applications, one method is to calculate numerically the stress-strain hysteresis curves of the interfaces silicon-solder-DCB and/or DCB-solder-baseplate inside the power modules. This can only be achieved if the transient junction temperatures in these layers are known for a defined mission profile. Therefore, one has to couple circuit simulation with thermal simulation and stress-strain computation. The second challenge of this problem is to perform this transient simulation taking into account switching losses in the {mu}s-range for mission profiles over a couple of minutes. In this paper we employ a new multi-domain simulation software to achieve results with reasonable computational effort. (author)

  20. An assessment of mercury in estuarine sediment and tissue in Southern New Jersey using public domain data

    Science.gov (United States)

    Ng, Kara; Szabo, Zoltan; Reilly, Pamela A.; Barringer, Julia; Smalling, Kelly L.

    2016-01-01

    Mercury (Hg) is considered a contaminant of global concern for coastal environments due to its toxicity, widespread occurrence in sediment, and bioaccumulation in tissue. Coastal New Jersey, USA, is characterized by shallow bays and wetlands that provide critical habitat for wildlife but share space with expanding urban landscapes. This study was designed as an assessment of the magnitude and distribution of Hg in coastal New Jersey sediments and critical species using publicly available data to highlight potential data gaps. Mercury concentrations in estuary sediments can exceed 2 μg/g and correlate with concentrations of other metals. Based on existing data, the concentrations of Hg in mussels in southern New Jersey are comparable to those observed in other urbanized Atlantic Coast estuaries. Lack of methylmercury data for sediments, other media, and tissues are data gaps needing to be filled for a clearer understanding of the impacts of Hg inputs to the ecosystem.

  1. Using dual-domain advective-transport simulation to reconcile multiple-tracer ages and estimate dual-porosity transport parameters

    Science.gov (United States)

    Sanford, Ward E.; Niel Plummer, L.; Casile, Gerolamo; Busenberg, Ed; Nelms, David L.; Schlosser, Peter

    2017-06-01

    Dual-domain transport is an alternative conceptual and mathematical paradigm to advection-dispersion for describing the movement of dissolved constituents in groundwater. Here we test the use of a dual-domain algorithm combined with advective pathline tracking to help reconcile environmental tracer concentrations measured in springs within the Shenandoah Valley, USA. The approach also allows for the estimation of the three dual-domain parameters: mobile porosity, immobile porosity, and a domain exchange rate constant. Concentrations of CFC-113, SF6, 3H, and 3He were measured at 28 springs emanating from carbonate rocks. The different tracers give three different mean composite piston-flow ages for all the springs that vary from 5 to 18 years. Here we compare four algorithms that interpret the tracer concentrations in terms of groundwater age: piston flow, old-fraction mixing, advective-flow path modeling, and dual-domain modeling. Whereas the second two algorithms made slight improvements over piston flow at reconciling the disparate piston-flow age estimates, the dual-domain algorithm gave a very marked improvement. Optimal values for the three transport parameters were also obtained, although the immobile porosity value was not well constrained. Parameter correlation and sensitivities were calculated to help quantify the uncertainty. Although some correlation exists between the three parameters being estimated, a watershed simulation of a pollutant breakthrough to a local stream illustrates that the estimated transport parameters can still substantially help to constrain and predict the nature and timing of solute transport. The combined use of multiple environmental tracers with this dual-domain approach could be applicable in a wide variety of fractured-rock settings.

  2. Domains and domain loss

    DEFF Research Database (Denmark)

    Haberland, Hartmut

    2005-01-01

    The domain concept, originally suggested by Schmidt-Rohr in the 1930’s (as credited in Fishman’s writings in the 1970s), was an attempt to sort out different areas of language use in multilingual societies, which are relevant for language choice. In Fishman’s version, domains were considered...... not described in terms of domains, and recent research e.g. about the multilingual communities in the Danish-German border area seems to confirm this....

  3. Visualizing Space Weather: The Planeterrella Auroral Simulator as a Heliophysics Public Outreach Tool

    Science.gov (United States)

    Masongsong, E. V.; Lilensten, J.; Booth, M. J.; Suri, G.; Heflinger, T. G.; Angelopoulos, V.

    2014-12-01

    The NASA THEMIS and ARTEMIS satellite missions study "space weather," which describes the solar wind influence on Earth's protective magnetic shield, the magnetosphere. Space weather is important to study and predict because it can damage critical GPS and communications satellites, harm space travelers, and even disable our global electrical grid. The Planeterrella is an innovative heliophysics outreach demonstration, expanding public awareness of space weather by visualizing the sun-Earth connection up close and in-person. Using a glass vacuum chamber, two magnetized spheres and a 1kV power supply, the device can simulate plasma configurations of the solar corona, solar wind, Van Allen radiation belts, and auroral ovals, all of which are observable only by satellites. This "aurora in a bottle" is a modernized version of the original Terrella built by Kristian Birkeland in the 1890s to show that the aurora are electrical in nature. Adapted from plans by Lilensten et al. at CNRS-IPAG, the UCLA Planeterrella was completed in Nov. 2013, the second device of its kind in the U.S., and the centerpiece of the THEMIS/ARTEMIS mobile public outreach exhibit. In combination with captivating posters, 3D magnetic field models, dazzling aurora videos and magnetosphere animations, the Planeterrella has already introduced over 1200 people to the electrical link between our sun and the planets. Most visitors had seen solar flare images in the news, however the Planeterrella experience enhanced their appreciation of the dynamic solar wind and its effects on Earth's invisible magnetic field. Most importantly, visitors young and old realized that magnets are not just cool toys or only for powering hybrid car motors and MRIs, they are a fundamental aspect of ongoing life on Earth and are key to the formation and evolution of planets, moons, and stars, extending far beyond our galaxy to other planetary systems throughout the universe. Novel visualizations such as the Planeterrella can

  4. The redundancy of NMR restraints can be used to accelerate the unfolding behavior of an SH3 domain during molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Duclert-Savatier Nathalie

    2011-11-01

    Full Text Available 1 Abstract Background The simulation of protein unfolding usually requires recording long molecular dynamics trajectories. The present work aims to figure out whether NMR restraints data can be used to probe protein conformations in order to accelerate the unfolding simulation. The SH3 domain of nephrocystine (nph SH3 was shown by NMR to be destabilized by point mutations, and was thus chosen to illustrate the proposed method. Results The NMR restraints observed on the WT nph SH3 domain were sorted from the least redundant to the most redundant ones. Protein NMR conformations were then calculated with: (i the set full including all NMR restraints measured on nph SH3, (ii the set reduced where the least redundant restraints with respect to the set full were removed, (iii the sets random where randomly picked-up restraints were removed. From each set of conformations, we recorded series of 5-ns MD trajectories. The β barrel architecture of nph SH3 in the trajectories starting from sets (i and (iii appears to be stable. On the contrary, on trajectories based on the set (ii, a displacement of the hydrophobic core residues and a variation of the β barrel inner cavity profile were observed. The overall nph SH3 destabilization agrees with previous experimental and simulation observations made on other SH3 domains. The destabilizing effect of mutations was also found to be enhanced by the removal of the least redundant restraints. Conclusions We conclude that the NMR restraint redundancy is connected to the instability of the SH3 nph domain. This restraint redundancy generalizes the contact order parameter, which is calculated from the contact map of a folded protein and was shown in the literature to be correlated to the protein folding rate. The relationship between the NMR restraint redundancy and the protein folding is also reminiscent of the previous use of the Gaussian Network Model to predict protein folding parameters.

  5. A simulation study of the impact of the public-private partnership strategy on the performance of transport infrastructure.

    Science.gov (United States)

    Huang, Zhengfeng; Zheng, Pengjun; Ma, Yanqiang; Li, Xuan; Xu, Wenjun; Zhu, Wanlu

    2016-01-01

    The choice of investment strategy has a great impact on the performance of transport infrastructure. Positive projects such as the "Subway plus Property" model in Hong Kong have created sustainable financial profits for the public transport projects. Owing to a series of public debt and other constraints, public-private partnership (PPP) was introduced as an innovative investment model to address this issue and help develop transport infrastructure. Yet, few studies provide a deeper understanding of relationships between PPP strategy and the performance of such transport projects (particularly the whole transport system). This paper defines the research scope as a regional network of freeway. With a popular PPP model, travel demand prediction method, and relevant parameters as input, agents in a simulation framework can simulate the choice of PPP freeway over time. The simulation framework can be used to analyze the relationship between the PPP strategy and performance of the regional freeway network. This study uses the Freeway Network of Yangtze River Delta (FN-YRD) in China as the context. The results demonstrate the value of using simulation models of complex transportation systems to help decision makers choose the right PPP projects. Such a tool is viewed as particularly important given the ongoing transformation of functions of the Chinese transportation sector, including franchise rights of transport projects, and freeway charging mechanism.

  6. An object-oriented designed finite-difference time-domain simulator for electromagnetic analysis and design in MRI--applications to high field analyses.

    Science.gov (United States)

    Wei, Q; Liu, F; Xia, L; Crozier, S

    2005-02-01

    This paper presents a finite-difference time-domain (FDTD) simulator for electromagnetic analysis and design applications in MRI. It is intended to be a complete FDTD model of an MRI system including all RF and low-frequency field generating units and electrical models of the patient. The program has been constructed in an object-oriented framework. The design procedure is detailed and the numerical solver has been verified against analytical solutions for simple cases and also applied to various field calculation problems. In particular, the simulator is demonstrated for inverse RF coil design, optimized source profile generation, and parallel imaging in high-frequency situations. The examples show new developments enabled by the simulator and demonstrate that the proposed FDTD framework can be used to analyze large-scale computational electromagnetic problems in modern MRI engineering.

  7. Thermal conductivity mapping of pyrolytic carbon and silicon carbide coatings on simulated fuel particles by time-domain thermoreflectance

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Honorato, E. [Materials Science Centre, School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom); Chiritescu, C. [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, IL 61801 (United States); Xiao, P. [Materials Science Centre, School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom)], E-mail: Ping.xiao@manchester.ac.uk; Cahill, David G. [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, IL 61801 (United States); Marsh, G.; Abram, T.J. [Nexia Solutions Ltd., Springfields PR4 0XJ (United Kingdom)

    2008-08-15

    Thermal conductivity of pyrolytic carbon and silicon carbide coatings on spherical particles has been mapped using time-domain thermoreflectance. The thermal conductivities measured for pyrolytic carbon ranged between 3.4 and 13.5 W/m K. The effect of porosity, pore-size distribution, anisotropy, in-plane disorder and domain sizes is discussed. A thermal conductivity of 168 W/m K was obtained for SiC. Mapping of the thermal conductivity of coated fuel particles provides useful data for modeling fuel performance during the operation of nuclear reactors.

  8. Current limitations of SNP data from the public domain for studies of complex disorders: a test for ten candidate genes for obesity and osteoporosis

    Directory of Open Access Journals (Sweden)

    Xiao Peng

    2004-02-01

    Full Text Available Abstract Background Public SNP databases are frequently used to choose SNPs for candidate genes in the association and linkage studies of complex disorders. However, their utility for such studies of diseases with ethnic-dependent background has never been evaluated. Results To estimate the accuracy and completeness of SNP public databases, we analyzed the allele frequencies of 41 SNPs in 10 candidate genes for obesity and/or osteoporosis in a large American-Caucasian sample (1,873 individuals from 405 nuclear families by PCR-invader assay. We compared our results with those from the databases and other published studies. Of the 41 SNPs, 8 were monomorphic in our sample. Twelve were reported for the first time for Caucasians and the other 29 SNPs in our sample essentially confirmed the respective allele frequencies for Caucasians in the databases and previous studies. The comparison of our data with other ethnic groups showed significant differentiation between the three major world ethnic groups at some SNPs (Caucasians and Africans differed at 3 of the 18 shared SNPs, and Caucasians and Asians differed at 13 of the 22 shared SNPs. This genetic differentiation may have an important implication for studying the well-known ethnic differences in the prevalence of obesity and osteoporosis, and complex disorders in general. Conclusion A comparative analysis of the SNP data of the candidate genes obtained in the present study, as well as those retrieved from the public domain, suggests that the databases may currently have serious limitations for studying complex disorders with an ethnic-dependent background due to the incomplete and uneven representation of the candidate SNPs in the databases for the major ethnic groups. This conclusion attests to the imperative necessity of large-scale and accurate characterization of these SNPs in different ethnic groups.

  9. Establishing the Public Sphere and Abolishing the Private Domain:The Rise of a Doctrine and Its Social Significance in the Spring and Autumn Period

    Institute of Scientific and Technical Information of China (English)

    Liu Zehua

    2006-01-01

    The dominant views regarding the concepts of "the public"(gong)and"the private"(si) took shape in the Spring and Autumn period and matured in the succeeding years of the Warring States period.This paper is an attempt to trace both the growth of the vocabulary containing "gong"and "si"and the development of philosophical views regarding issues that center on the relation between the individual and the larger social/communal/political body,of which that individual is a member;it also touches on issues related to the proper handling of public afrairs and the relation between state,sovereign,and the individual.The era is often characterized as"The Contention of the Hundred Schools of Thought,"notwithstanding it ended with but one view that is universally accepted by thinkers of diverse persuasion,namely,si is the source of all social evil and.therefore,should be condemned.This is the doctrine known as ligong miesi(abolishing si so gong may be established),which contributed to the orthodox for that era and the millennium to come.By extolling gong and condemning si.it painted a portrait of the Pair as two irreconcilable nomas or forces in social and political life;it provided a iustification for the then emerging new social arrangement and Ways of distribution of power and resources.and it also led to acute conflicts between the sovereign andthe state,the ruledandthe ruler,the stateandthe subject,as well as the public sphere and the private domain.

  10. Optical simulation of in-plane-switching blue phase liquid crystal display using the finite-difference time-domain method

    Science.gov (United States)

    Dou, Hu; Ma, Hongmei; Sun, Yu-Bao

    2016-09-01

    The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display. Compared with the matrix optic methods and the refractive method, the finite-difference time-domain method, which is used to directly solve Maxwell’s equations, can consider the lateral variation of the refractive index and obtain an accurate convergence effect. The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage. The finite-difference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change. Project supported by the National Natural Science Foundation of China (Grant Nos. 11304074, 61475042, and 11274088), the Natural Science Foundation of Hebei Province, China (Grant Nos. A2015202320 and GCC2014048), and the Key Subject Construction Project of Hebei Province University, China.

  11. Final Report for Time Domain Boundary Element and Hybrid Finite Element Simulation for Maxwell's Equations

    Energy Technology Data Exchange (ETDEWEB)

    Pingenot, J; Jandhyala, V

    2007-03-01

    This report summarizes the work performed for Lawrence Livermore National Laboratory (LLNL) at the University of Washington between September 2004 and May 2006. This project studied fast solvers and stability for time domain integral equations (TDIE), especially as applied to radiating boundary for a massively parallel FEM solver.

  12. Performance of ICTP's RegCM4 in Simulating the Rainfall Characteristics over the CORDEX-SEA Domain

    Science.gov (United States)

    Neng Liew, Ju; Tangang, Fredolin; Tieh Ngai, Sheau; Chung, Jing Xiang; Narisma, Gemma; Cruz, Faye Abigail; Phan Tan, Van; Thanh, Ngo-Duc; Santisirisomboon, Jerasron; Milindalekha, Jaruthat; Singhruck, Patama; Gunawan, Dodo; Satyaningsih, Ratna; Aldrian, Edvin

    2015-04-01

    The performance of the RegCM4 in simulating rainfall variations over the Southeast Asia regions was examined. Different combinations of six deep convective parameterization schemes, namely i) Grell scheme with Arakawa-Schubert closure assumption, ii) Grell scheme with Fritch-Chappel closure assumption, iii) Emanuel MIT scheme, iv) mixed scheme with Emanuel MIT scheme over the Ocean and the Grell scheme over the land, v) mixed scheme with Grell scheme over the land and Emanuel MIT scheme over the ocean and (vi) Kuo scheme, and three ocean flux treatments were tested. In order to account for uncertainties among the observation products, four different gridded rainfall products were used for comparison. The simulated climate is generally drier over the equatorial regions and slightly wetter over the mainland Indo-China compare to the observation. However, simulation with MIT cumulus scheme used over the land area consistently produces large amplitude of positive rainfall biases, although it simulates more realistic annual rainfall variations. The simulations are found less sensitive to treatment of ocean fluxes. Although the simulations produced the rainfall climatology well, all of them simulated much stronger interannual variability compare to that of the observed. Nevertheless, the time evolution of the inter-annual variations was well reproduced particularly over the eastern part of maritime continent. Over the mainland Southeast Asia (SEA), unrealistic rainfall anomalies processes were simulated. The lacking of summer season air-sea interaction results in strong oceanic forcings over the regions, leading to positive rainfall anomalies during years with warm ocean temperature anomalies. This incurs much stronger atmospheric forcings on the land surface processes compare to that of the observed. A score ranking system was designed to rank the simulations according to their performance in reproducing different aspects of rainfall characteristics. The result suggests

  13. 时域和空间域路面激励下重型辆动载荷仿真分析%Simulation Analysis of Heavy-duty Vehicle Dynamic Load under Road Excitation in Time Domain and Spatial Domain

    Institute of Scientific and Technical Information of China (English)

    蒋荣超; 刘大维; 王松; 康忠亮

    2012-01-01

    In order to study the dynamic load characteristics of heavy-duty vehicle under road excitation in time domain and spatial domain, a rigid flexible coupling virtual vehicle prototype was established using SIMPACK software. The tires and leaf springs were treated as deformable body, and the rubber pads and limit block were simplified to force elements with non-linear stiffness and damping characteristics. And time domain and spatial domain mathematical models of road excitation were established using the harmony superposition method based on power spectral density of rational function. Then a dynamic model of vehicle under road excitation in time domain and spatial domain was established, and the vehicle tire normal force and tire normal dynamic load coefficient were computed. The simulation results indicate that (1) at different driving speeds, the values and change regularities of tire normal forces obtained under the road excitation in time domain and spatial domain were not the same, and the maximum values of tire normal force appeared at different location; (2) the change regularities of the middle and the rear axles' tire normal dynamic load coefficients were basically similar, while those of the front axle's tire normal dynamic load coefficient were different. The research results could provide a basis for calculation, verification and prediction of vehicle tire dynamic load.%为研究时间和空间频率路面激励下重型车辆动载特性,将车辆的轮胎、钢板弹簧视为柔体,橡胶垫块、限位块简化为具有非线性刚度和阻尼特性的力元,采用多体动力学仿真软件SIMPACK建立刚柔耦合的车辆整车虚拟样机,并采用有理函数功率谱密度的谐波叠加法建立空间域和时域路面激励数学模型,创建一个时域和空间域路面激励下车辆行驶动力学模型,仿真计算了车辆各轴轮胎的法向作用力和车轮法向动栽系数.结果表明:不同车速下,时域和空间域路面激

  14. A high-resolution coupled meteorology-smoke modeling system HRRR-Smoke to simulate air quality over the CONUS domain in real time

    Science.gov (United States)

    Ahmadov, Ravan; Grell, Georg; James, Eric; Freitas, Saulo; Pereira, Gabriel; Csiszar, Ivan; Tsidulko, Marina; Pierce, Brad; McKeen, Stuart; Peckham, Steven; Alexander, Curtis; Saide, Pablo; Benjamin, Stan

    2017-04-01

    In this talk we discuss a new smoke modeling system High Resolution Rapid Refresh (HRRR-Smoke) to simulate biomass burning (BB) emissions, plume rise and smoke transport in real time. The HRRR (without smoke) is run operational at the National Weather Service, and includes an aerosol aware microphysics scheme. It is NOAA/ESRL's version of the Weather Research and Forecasting (WRF) model. Here we make use of WRF-Chem (the WRF model coupled with chemistry) and simulate fine particulate matter (PM2.5 or smoke) emissions emitted by BB as well as anthropogenic sources. The model also includes dry and wet deposition of aerosols. The modeling system ingests fire radiative power (FRP) data from the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor to calculate BB emissions. Using the FRP data and simulated meteorology the model calculates plume rise in an online mode. The HRRR-Smoke model has been running in real-time, originally without any feedback effects, since June 2016 on 3km horizontal grid resolution over the contiguous US (CONUS) domain by NOAA/ESRL Global Systems Division. We simulate HRRR-Smoke for August 2015 and 2016 time periods over the CONUS domain to conduct the model evaluations. Simulated smoke concentrations are evaluated using hourly PM2.5 measurements from EPA's Air Quality System network. The HRRR-Smoke model uses a double moment aerosol aware microphysics scheme, which enables an efficient coupling between smoke and meteorology. We explore the impact of smoke on radiation, cloud and precipitation fields, whether the inclusion of the feedback processes improves the weather prediction skill of the model.

  15. Monte Carlo Simulation Of Emission Tomography And Other Medical Imaging Techniques.

    Science.gov (United States)

    Harrison, Robert L

    2010-01-05

    An introduction to Monte Carlo simulation of emission tomography. This paper reviews the history and principles of Monte Carlo simulation, then applies these principles to emission tomography using the public domain simulation package SimSET (a Simulation System for Emission Tomography) as an example. Finally, the paper discusses how the methods are modified for X-ray computed tomography and radiotherapy simulations.

  16. Feasibility Analysis of Low Cost Graphical Processing Units for Electromagnetic Field Simulations by Finite Difference Time Domain Method

    CERN Document Server

    Choudhari, A V; Gupta, M R

    2013-01-01

    Among several techniques available for solving Computational Electromagnetics (CEM) problems, the Finite Difference Time Domain (FDTD) method is one of the best suited approaches when a parallelized hardware platform is used. In this paper we investigate the feasibility of implementing the FDTD method using the NVIDIA GT 520, a low cost Graphical Processing Unit (GPU), for solving the differential form of Maxwell's equation in time domain. Initially a generalized benchmarking problem of bandwidth test and another benchmarking problem of 'matrix left division is discussed for understanding the correlation between the problem size and the performance on the CPU and the GPU respectively. This is further followed by the discussion of the FDTD method, again implemented on both, the CPU and the GT520 GPU. For both of the above comparisons, the CPU used is Intel E5300, a low cost dual core CPU.

  17. Numerical simulation of digital holographic microscopy through transparent samples based on pupil imaging and finite-difference time-domain methods.

    Science.gov (United States)

    Hadachi, Hirotaka; Saito, Takashi

    2013-04-20

    Digital holographic microscopy (DHM) has been used to determine the morphology and shape of transparent objects. However, the obtained shape is often inaccurate depending on the object properties and the setup of the optical imaging system. To understand these effects, we developed a new DHM model on the basis of a hybrid pupil imaging and finite-difference time-domain method. To demonstrate this model, we compared the results of an experiment with those of a simulation using borosilicate glass microspheres and a mold with a linear step structure. The simulation and experimental results showed good agreement. We also showed how the curvature and refractive index of objects affect the accuracy of thickness measurements.

  18. Impact of resolution on aerosol radiative feedbacks with in online-coupled chemistry/climate simulations (WRF-Chem) for EURO-CORDEX compliant domains

    Science.gov (United States)

    López-Romero, Jose Maria; Baró, Rocío; Palacios-Peña, Laura; Jerez, Sonia; Jiménez-Guerrero, Pedro; Montávez, Juan Pedro

    2016-04-01

    Several studies have shown that a high spatial resolution in atmospheric model runs improves the simulation of some meteorological variables, such as precipitation, particularly extreme events and in regions with complex orography [1]. However, increasing model spatial resolution makes the computational time rise exponentially. Hence, very high resolution experiments on large domains can hamper the execution of climatic runs. This problem shoots up when using online-coupled chemistry climate models, making a careful evaluation of improvements versus costs mandatory. Under this umbrella, the objective of this work is to investigate the sensitivity of aerosol radiative feedbacks from online-coupled chemistry regional model simulations to the spatial resolution. For that, the WRF-Chem [2] model is used for a case study to simulate the episode occurring between July 25th and August 15th of 2010. It is characterized by a high loading of atmospheric aerosol particles coming mainly from wildfires over large European regions (Russia, Iberian Peninsula). Three spatial resolutions are used defined for Euro-Cordex compliant domains [3]: 0.44°, 0.22° and 0.11°. Anthropogenic emissions come from TNO databases [4]. The analysis focuses on air quality variables (mainly PM10, PM2.5), meteorological variables (temperature, radiation) and other aerosol optical properties (aerosol optical depth). The CPU time ratio for the different domains is 1 (0.44°), 4(0.22°) and 28(0.11°) (normalized times). Comparison among simulations and observations are analyzed. Preliminary results show the difficulty to justify the much larger computational cost of high-resolution experiments when comparing with observations from a meteorological point of view, despite the finer spatio-temporal detail of the obtained pollutant fields. [1] Prein, A. F. (2014, December). Precipitation in the EURO-CORDEX 0.11° and 0.44° simulations: high resolution, high benefits?. In AGU Fall Meeting Abstracts (Vol

  19. A numerical approach for simulating fluid structure interaction of flexible thin shells undergoing arbitrarily large deformations in complex domains

    Energy Technology Data Exchange (ETDEWEB)

    Gilmanov, Anvar, E-mail: agilmano@umn.edu [Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414 (United States); Le, Trung Bao, E-mail: lebao002@umn.edu [Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414 (United States); Sotiropoulos, Fotis, E-mail: fotis@umn.edu [Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414 (United States); Department of Civil, Environmental and Geo-Engineering, University of Minnesota, Minneapolis, MN 55414 (United States)

    2015-11-01

    We present a new numerical methodology for simulating fluid–structure interaction (FSI) problems involving thin flexible bodies in an incompressible fluid. The FSI algorithm uses the Dirichlet–Neumann partitioning technique. The curvilinear immersed boundary method (CURVIB) is coupled with a rotation-free finite element (FE) model for thin shells enabling the efficient simulation of FSI problems with arbitrarily large deformation. Turbulent flow problems are handled using large-eddy simulation with the dynamic Smagorinsky model in conjunction with a wall model to reconstruct boundary conditions near immersed boundaries. The CURVIB and FE solvers are coupled together on the flexible solid–fluid interfaces where the structural nodal positions, displacements, velocities and loads are calculated and exchanged between the two solvers. Loose and strong coupling FSI schemes are employed enhanced by the Aitken acceleration technique to ensure robust coupling and fast convergence especially for low mass ratio problems. The coupled CURVIB-FE-FSI method is validated by applying it to simulate two FSI problems involving thin flexible structures: 1) vortex-induced vibrations of a cantilever mounted in the wake of a square cylinder at different mass ratios and at low Reynolds number; and 2) the more challenging high Reynolds number problem involving the oscillation of an inverted elastic flag. For both cases the computed results are in excellent agreement with previous numerical simulations and/or experiential measurements. Grid convergence tests/studies are carried out for both the cantilever and inverted flag problems, which show that the CURVIB-FE-FSI method provides their convergence. Finally, the capability of the new methodology in simulations of complex cardiovascular flows is demonstrated by applying it to simulate the FSI of a tri-leaflet, prosthetic heart valve in an anatomic aorta and under physiologic pulsatile conditions.

  20. A numerical approach for simulating fluid structure interaction of flexible thin shells undergoing arbitrarily large deformations in complex domains

    Science.gov (United States)

    Gilmanov, Anvar; Le, Trung Bao; Sotiropoulos, Fotis

    2015-11-01

    We present a new numerical methodology for simulating fluid-structure interaction (FSI) problems involving thin flexible bodies in an incompressible fluid. The FSI algorithm uses the Dirichlet-Neumann partitioning technique. The curvilinear immersed boundary method (CURVIB) is coupled with a rotation-free finite element (FE) model for thin shells enabling the efficient simulation of FSI problems with arbitrarily large deformation. Turbulent flow problems are handled using large-eddy simulation with the dynamic Smagorinsky model in conjunction with a wall model to reconstruct boundary conditions near immersed boundaries. The CURVIB and FE solvers are coupled together on the flexible solid-fluid interfaces where the structural nodal positions, displacements, velocities and loads are calculated and exchanged between the two solvers. Loose and strong coupling FSI schemes are employed enhanced by the Aitken acceleration technique to ensure robust coupling and fast convergence especially for low mass ratio problems. The coupled CURVIB-FE-FSI method is validated by applying it to simulate two FSI problems involving thin flexible structures: 1) vortex-induced vibrations of a cantilever mounted in the wake of a square cylinder at different mass ratios and at low Reynolds number; and 2) the more challenging high Reynolds number problem involving the oscillation of an inverted elastic flag. For both cases the computed results are in excellent agreement with previous numerical simulations and/or experiential measurements. Grid convergence tests/studies are carried out for both the cantilever and inverted flag problems, which show that the CURVIB-FE-FSI method provides their convergence. Finally, the capability of the new methodology in simulations of complex cardiovascular flows is demonstrated by applying it to simulate the FSI of a tri-leaflet, prosthetic heart valve in an anatomic aorta and under physiologic pulsatile conditions.

  1. 基于特定领域建模的仿真组件建模方法%Simulation Component Modeling Method Based on Domain-specific Modeling

    Institute of Scientific and Technical Information of China (English)

    赵晨阳

    2014-01-01

    The development of current Simulation Component Model(SCM ) was difficult and low efficiency .Firstly ,on the basis of the theory of Domain-Specific Modeling (DSM ) ,the parts of SCM metamodel were determined and the relations between them were identified by analyzing the basic structure and characteristics .Then ,a development approach of SCM and the development process of SCM were proposed based on DSM .The Simulation Component Model Modeling language(SCMML) metamodel was constructed by using Visual Studio Visualization and Modeling SDK (VMSDK ) Tool . Finally , it was demonstrated that this method could significantly improve the development efficiency of SCM with case study .%针对当前仿真组件模型(SCM ,Simulation Component Model)开发存在的问题,首先采用特定领域建模(DSM ,Domain-Specific Modeling)理论,通过分析仿真组件的基本结构和特征,确定仿真组件元模型整体的各部分模块及其相互关系,然后提出一种基于特定领域建模的仿真组件的建模方法和仿真组件模型开发流程。利用VMSDK (Visual Studio Visualization and Modeling SDK )工具,构建了描述仿真组件领域建模语言(SCMML ,Simulation Component Model Modeling language)的元模型。最后,通过建模实例,表明该方法可显著提高仿真组件的开发效率。

  2. A pseudo-spectral method for the simulation of poro-elastic seismic wave propagation in 2D polar coordinates using domain decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Sidler, Rolf, E-mail: rsidler@gmail.com [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland); Carcione, José M. [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42c, 34010 Sgonico, Trieste (Italy); Holliger, Klaus [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)

    2013-02-15

    We present a novel numerical approach for the comprehensive, flexible, and accurate simulation of poro-elastic wave propagation in 2D polar coordinates. An important application of this method and its extensions will be the modeling of complex seismic wave phenomena in fluid-filled boreholes, which represents a major, and as of yet largely unresolved, computational problem in exploration geophysics. In view of this, we consider a numerical mesh, which can be arbitrarily heterogeneous, consisting of two or more concentric rings representing the fluid in the center and the surrounding porous medium. The spatial discretization is based on a Chebyshev expansion in the radial direction and a Fourier expansion in the azimuthal direction and a Runge–Kutta integration scheme for the time evolution. A domain decomposition method is used to match the fluid–solid boundary conditions based on the method of characteristics. This multi-domain approach allows for significant reductions of the number of grid points in the azimuthal direction for the inner grid domain and thus for corresponding increases of the time step and enhancements of computational efficiency. The viability and accuracy of the proposed method has been rigorously tested and verified through comparisons with analytical solutions as well as with the results obtained with a corresponding, previously published, and independently benchmarked solution for 2D Cartesian coordinates. Finally, the proposed numerical solution also satisfies the reciprocity theorem, which indicates that the inherent singularity associated with the origin of the polar coordinate system is adequately handled.

  3. Switching Operation Simulations in a Large Offshore Wind Farm with Use of Parametric Variation and Frequency Domain Severity Factor

    DEFF Research Database (Denmark)

    Holdyk, Andrzej; Holbøll, Joachim; Arana, Ivan;

    2012-01-01

    Transient voltages resulting from switching operations depend on an interaction between the breaker, the transformer, cables and a neighbourhood grid and imply a risk for the transformer and other components. In this paper the Frequency Domain Severity Factor (FDSF) is used to assess the severity...... implemented in ATP-EMTP using standard component models and further validated against measurements. The results show the range of overvoltages on the transformer terminals as well as the corresponding FSDF for all turbines under a number of varying parameters. The maximum FDSF of 1.235 and frequency of 445 k...

  4. A publicly available simulation of an enhanced network region of the Sun

    CERN Document Server

    Carlsson, Mats; Gudiksen, Boris V; Leenaarts, Jorrit; De Pontieu, Bart

    2016-01-01

    Context. The solar chromosphere is the interface between the solar surface and the solar corona. Modelling of this region is difficult because it represents the transition from optically thick to thin radiation escape, from gas-pressure domination to magnetic-pressure domination, from a neutral to an ionised state, from MHD to plasma physics, and from near-equilibrium (LTE) to non-equilibrium conditions. Aims. Our aim is to provide the community with realistic simulations of the magnetic solar outer atmosphere. This will enable detailed comparison of existing and upcoming observations with synthetic observables from the simulations, thereby elucidating the complex interactions of magnetic fields and plasma that are crucial for our understanding of the dynamic outer atmosphere. Methods. We used the radiation magnetohydrodynamics code Bifrost to perform simulations of a computational volume with a magnetic field topology similar to an enhanced network area on the Sun. Results. The full simulation cubes are made...

  5. A publicly available simulation of an enhanced network region of the Sun

    Science.gov (United States)

    Carlsson, Mats; Hansteen, Viggo H.; Gudiksen, Boris V.; Leenaarts, Jorrit; De Pontieu, Bart

    2016-01-01

    Context. The solar chromosphere is the interface between the solar surface and the solar corona. Modelling of this region is difficult because it represents the transition from optically thick to thin radiation escape, from gas-pressure domination to magnetic-pressure domination, from a neutral to an ionised state, from MHD to plasma physics, and from near-equilibrium (LTE) to non-equilibrium conditions. Aims: Our aim is to provide the community with realistic simulations of the magnetic solar outer atmosphere. This will enable detailed comparison of existing and upcoming observations with synthetic observables from the simulations, thereby elucidating the complex interactions of magnetic fields and plasma that are crucial for our understanding of the dynamic outer atmosphere. Methods: We used the radiation magnetohydrodynamics code Bifrost to perform simulations of a computational volume with a magnetic field topology similar to an enhanced network area on the Sun. Results: The full simulation cubes are made available from the Hinode Science Data Centre Europe. The general properties of the simulation are discussed, and limitations are discussed. The Hinode Science Data Centre Europe (http://www.sdc.uio.no/search/simulations).

  6. Molecular dynamics simulation reveals insights into the mechanism of unfolding by the A130T/V mutations within the MID1 zinc-binding Bbox1 domain.

    Directory of Open Access Journals (Sweden)

    Yunjie Zhao

    Full Text Available The zinc-binding Bbox1 domain in protein MID1, a member of the TRIM family of proteins, facilitates the ubiquitination of the catalytic subunit of protein phosphatase 2A and alpha4, a protein regulator of PP2A. The natural mutation of residue A130 to a valine or threonine disrupts substrate recognition and catalysis. While NMR data revealed the A130T mutant Bbox1 domain failed to coordinate both structurally essential zinc ions and resulted in an unfolded structure, the unfolding mechanism is unknown. Principle component analysis revealed that residue A130 served as a hinge point between the structured β-strand-turn-β-strand (β-turn-β and the lasso-like loop sub-structures that constitute loop1 of the ββα-RING fold that the Bbox1 domain adopts. Backbone RMSD data indicate significant flexibility and departure from the native structure within the first 5 ns of the molecular dynamics (MD simulation for the A130V mutant (>6 Å and after 30 ns for A130T mutant (>6 Å. Overall RMSF values were higher for the mutant structures and showed increased flexibility around residues 125 and 155, regions with zinc-coordinating residues. Simulated pKa values of the sulfhydryl group of C142 located near A130 suggested an increased in value to ~9.0, paralleling the increase in the apparent dielectric constants for the small cavity near residue A130. Protonation of the sulfhydryl group would disrupt zinc-coordination, directly contributing to unfolding of the Bbox1. Together, the increased motion of residues of loop 1, which contains four of the six zinc-binding cysteine residues, and the increased pKa of C142 could destabilize the structure of the zinc-coordinating residues and contribute to the unfolding.

  7. Construction of a novel coarse grain model for simulations of HIV capsid assembly to capture the backbone structure and inter-domain motions in solution

    Directory of Open Access Journals (Sweden)

    Xin Qiao

    2015-12-01

    Full Text Available We show the construction of a novel coarse grain model for simulations of HIV capsid assembly based on four structural models of HIV capsid proteins: isolated hexamer 3H47.pdb, tubular assembly 3J34.pdb, isolated pentamer 3P05.pdb and C-terminus dimer 2KOD.pdb. The data demonstrates the derivation of inter-domain motions from all atom Molecular Dynamics simulations and comparison with the motions derived from the analysis of solution NMR results defined in 2M8L.pdb. Snapshots from a representative Monte Carlo simulation with 128 dimeric subunit proteins based on 3J34.pdb are shown in addition to the quantitative analysis of its assembly pathway. Movies of the assembly process are compiled with snapshots of representative simulations of four structural models. The methods and data in this article were utilized in Qiao et al. (in press [1] to probe the mechanism of polymorphism and curvature control of HIV capsid assembly.

  8. Qualitative assessment of PMIP3 rainfall simulations across the eastern African monsoon domains during the mid-Holocene and the Last Glacial Maximum

    Science.gov (United States)

    Chevalier, Manuel; Brewer, Simon; Chase, Brian M.

    2017-01-01

    In this paper we compare a compilation of multiproxy records spanning the eastern African margin with general circulation model simulations of seasonal precipitation fields for the mid-Holocene and the Last Glacial Maximum (LGM) carried out as part of the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3). Results show good agreement during the mid-Holocene (the '6K experiment'), with palaeodata and model outputs correlating well and indicating that changes in insolation drove a stronger northern African monsoon (north of ∼0-5°S) during the terminal "African Humid Period" and a weaker southeast African monsoon. For the LGM (the '21K experiment'), however, significant discrepancies exist both between model simulations, and between existing palaeodata and simulated conditions, both in terms of direction and amplitude of change. None of the PMIP3 simulations reflect the pattern inferred from the palaeodata. Two major discrepancies have been identified to explain this: 1) the limited sensitivity of the southern monsoon domain to the colder temperatures of the Indian Ocean (-2 °C), and 2) the absence of changes in the dynamic of the Indian Ocean Walker circulation over the entire basin, despite the exposure of the Sahul and Sunda shelves that weakened convection over the Indo-Pacific Warm Pool during the LGM. These results indicate that some major features of the atmospheric and oceanic teleconnections between the different monsoon regions require further consideration as models evolve.

  9. 网络微博中公共领域与私人领域的融合%The Fusion of the Public Domain and Private Sphere in Network Micro Blog

    Institute of Scientific and Technical Information of China (English)

    石良

    2012-01-01

    It is clarified that based on the public domain and the private sphere,the paper chooses the micro blog as a starting point,takes examples from sociological theory such as discursive power,social role,and opinion leaders,the fusion tendency of the public domain-private sector in the network——the public domain personal and private sector public is clarified.And it is analyzed that based on reality,the effect is brought to the society by fusion of the public or private field.%把微博作为切入点,借鉴话语权、社会角色、意见领袖等社会学理论阐释了网络中公共领域和私人领域融合的趋势——公共领域私人化与私人领域公共化。并且立足现实,分析了公私领域融合给社会带来的现实影响。

  10. The Evolution of 21-cm Structure (EOS): public, large-scale simulations of Cosmic Dawn and Reionization

    CERN Document Server

    Mesinger, Andrei; Sobacchi, Emanuele

    2016-01-01

    We introduce the Evolution of 21-cm Structure (EOS) project: providing periodic, public releases of the latest cosmological 21-cm simulations. 21-cm interferometry is set to revolutionize studies of the Cosmic Dawn (CD) and epoch of reionization (EoR), eventually resulting in 3D maps of the first billion years of our Universe. Progress will depend on sophisticated data analysis pipelines, which are in turn tested on large-scale mock observations. Here we present the 2016 EOS data release, consisting of the largest (1.6 Gpc on side with a 1024^3 grid), public 21-cm simulations of the CD and EoR. We include calibrated, sub-grid prescriptions for inhomogeneous recombinations and photo-heating suppression of star formation in small mass galaxies. We present two simulation runs that approximately bracket the contribution from faint unseen galaxies. From these two extremes, we predict that the duration of reionization (defined as a change in the mean neutral fraction from 0.9 to 0.1) should be between 2.7 < Delt...

  11. Simulation of Sentinel-3 images by four stream surface atmosphere radiative transfer modeling in the optical and thermal domains

    NARCIS (Netherlands)

    Verhoef, W.; Bach, H.

    2012-01-01

    Simulation of future satellite images can be applied in order to validate the general mission concept and to test the performance of advanced multi-sensor algorithms for the retrieval of surface parameters. This paper describes the radiative transfer modeling part of a so-called Land Scene Generator

  12. Parallel Fokker–Planck-DSMC algorithm for rarefied gas flow simulation in complex domains at all Knudsen numbers

    Energy Technology Data Exchange (ETDEWEB)

    Küchlin, Stephan, E-mail: kuechlin@ifd.mavt.ethz.ch; Jenny, Patrick

    2017-01-01

    A major challenge for the conventional Direct Simulation Monte Carlo (DSMC) technique lies in the fact that its computational cost becomes prohibitive in the near continuum regime, where the Knudsen number (Kn)—characterizing the degree of rarefaction—becomes small. In contrast, the Fokker–Planck (FP) based particle Monte Carlo scheme allows for computationally efficient simulations of rarefied gas flows in the low and intermediate Kn regime. The Fokker–Planck collision operator—instead of performing binary collisions employed by the DSMC method—integrates continuous stochastic processes for the phase space evolution in time. This allows for time step and grid cell sizes larger than the respective collisional scales required by DSMC. Dynamically switching between the FP and the DSMC collision operators in each computational cell is the basis of the combined FP-DSMC method, which has been proven successful in simulating flows covering the whole Kn range. Until recently, this algorithm had only been applied to two-dimensional test cases. In this contribution, we present the first general purpose implementation of the combined FP-DSMC method. Utilizing both shared- and distributed-memory parallelization, this implementation provides the capability for simulations involving many particles and complex geometries by exploiting state of the art computer cluster technologies.

  13. Simulation of Sentinel-3 images by four stream surface atmosphere radiative transfer modeling in the optical and thermal domains

    NARCIS (Netherlands)

    Verhoef, W.; Bach, H.

    2012-01-01

    Simulation of future satellite images can be applied in order to validate the general mission concept and to test the performance of advanced multi-sensor algorithms for the retrieval of surface parameters. This paper describes the radiative transfer modeling part of a so-called Land Scene Generator

  14. Flow in complex domains simulated by Dissipative Particle Dynamics driven by geometry-specific body-forces

    Science.gov (United States)

    Yazdani, Alireza; Deng, Mingge; Caswell, Bruce; Karniadakis, George Em

    2016-01-01

    We demonstrate how the quality of simulations by Dissipative Particle Dynamics (DPD) of flows in complex geometries is greatly enhanced when driven by body forces suitably tailored to the geometry. In practice, the body force fields are most conveniently chosen to be the pressure gradient of the corresponding Navier-Stokes (N-S) flow. In the first of three examples, the driving-force required to yield a stagnation-point flow is derived from the pressure field of the potential flow for a lattice of counter-rotating line vortices. Such a lattice contains periodic squares bounded by streamlines with four vortices within them. Hence, the DPD simulation can be performed with periodic boundary conditions to demonstrate the value of a non-uniform driving-force without the need to model real boundaries. The second example is an irregular geometry consisting of a 2D rectangular cavity on one side of an otherwise uniform channel. The Navier-Stokes pressure field for the same geometry is obtained numerically, and its interpolated gradient is then employed as the driving-force for the DPD simulation. Finally, we present a third example, where the proposed method is applied to a complex 3D geometry of an asymmetric constriction. It is shown that in each case the DPD simulations closely reproduce the Navier-Stokes solutions. Convergence rates are found to be much superior to alternative methods; in addition, the range of convergence with respect to Reynolds number and Mach number is greatly extended.

  15. Parallel Fokker-Planck-DSMC algorithm for rarefied gas flow simulation in complex domains at all Knudsen numbers

    Science.gov (United States)

    Küchlin, Stephan; Jenny, Patrick

    2017-01-01

    A major challenge for the conventional Direct Simulation Monte Carlo (DSMC) technique lies in the fact that its computational cost becomes prohibitive in the near continuum regime, where the Knudsen number (Kn)-characterizing the degree of rarefaction-becomes small. In contrast, the Fokker-Planck (FP) based particle Monte Carlo scheme allows for computationally efficient simulations of rarefied gas flows in the low and intermediate Kn regime. The Fokker-Planck collision operator-instead of performing binary collisions employed by the DSMC method-integrates continuous stochastic processes for the phase space evolution in time. This allows for time step and grid cell sizes larger than the respective collisional scales required by DSMC. Dynamically switching between the FP and the DSMC collision operators in each computational cell is the basis of the combined FP-DSMC method, which has been proven successful in simulating flows covering the whole Kn range. Until recently, this algorithm had only been applied to two-dimensional test cases. In this contribution, we present the first general purpose implementation of the combined FP-DSMC method. Utilizing both shared- and distributed-memory parallelization, this implementation provides the capability for simulations involving many particles and complex geometries by exploiting state of the art computer cluster technologies.

  16. Multi-Domain Modeling and Simulation of an Aircraft System for Advanced Vehicle-Level Reasoning Research and Development

    Directory of Open Access Journals (Sweden)

    : F. Khan

    2014-05-01

    Full Text Available In this paper, we describe a simulation based health monitoring system test-bed for aircraft systems. The purpose of the test-bed is to provide a technology neutral basis for implementing and evaluation of reasoning systems on vehicle level and software architecture in support of the safety and maintenance process. This simulation test-bed will provide the sub-system level results and data which can be fed to the VLRS to generate vehicle level reasoning to achieve broader level diagnoses. This paper describes real-time system architecture and concept of operations for the aircraft major sub-systems. The four main components in the real-time test-bed are the aircraft sub-systems (e.g. battery, fuel, engine, generator, heating and lighting system simulation model, fault insertion unit, health monitoring data processing and user interface. In this paper, we adopted a component based modelling paradigm for the implementation of the virtual aircraft systems. All of the fault injections are currently implemented via software. The fault insertion unit allows for the repeatable injection of faults into the system. The simulation test-bed has been tested with many different faults which were undetected on system level to process and detect on the vehicle level reasoning. This article also shows how one system fault can affect the overall health of the vehicle.

  17. Assessment of two versions of regional climate model in simulating the Indian Summer Monsoon over South Asia CORDEX domain

    Science.gov (United States)

    Pattnayak, K. C.; Panda, S. K.; Saraswat, Vaishali; Dash, S. K.

    2017-07-01

    This study assess the performance of two versions of Regional Climate Model (RegCM) in simulating the Indian summer monsoon over South Asia for the period 1998 to 2003 with an aim of conducting future climate change simulations. Two sets of experiments were carried out with two different versions of RegCM (viz. RegCM4.2 and RegCM4.3) with the lateral boundary forcings provided from European Center for Medium Range Weather Forecast Reanalysis (ERA-interim) at 50 km horizontal resolution. The major updates in RegCM4.3 in comparison to the older version RegCM4.2 are the inclusion of measured solar irradiance in place of hardcoded solar constant and additional layers in the stratosphere. The analysis shows that the Indian summer monsoon rainfall, moisture flux and surface net downward shortwave flux are better represented in RegCM4.3 than that in the RegCM4.2 simulations. Excessive moisture flux in the RegCM4.2 simulation over the northern Arabian Sea and Peninsular India resulted in an overestimation of rainfall over the Western Ghats, Peninsular region as a result of which the all India rainfall has been overestimated. RegCM4.3 has performed well over India as a whole as well as its four rainfall homogenous zones in reproducing the mean monsoon rainfall and inter-annual variation of rainfall. Further, the monsoon onset, low-level Somali Jet and the upper level tropical easterly jet are better represented in the RegCM4.3 than RegCM4.2. Thus, RegCM4.3 has performed better in simulating the mean summer monsoon circulation over the South Asia. Hence, RegCM4.3 may be used to study the future climate change over the South Asia.

  18. The impact of range anxiety and home, workplace, and public charging infrastructure on simulated battery electric vehicle lifetime utility

    Science.gov (United States)

    Neubauer, Jeremy; Wood, Eric

    2014-07-01

    Battery electric vehicles (BEVs) offer the potential to reduce both oil imports and greenhouse gas emissions, but have a limited utility due to factors including driver range anxiety and access to charging infrastructure. In this paper we apply NREL's Battery Lifetime Analysis and Simulation Tool for Vehicles (BLAST-V) to examine the sensitivity of BEV utility to range anxiety and different charging infrastructure scenarios, including variable time schedules, power levels, and locations (home, work, and public installations). We find that the effects of range anxiety can be significant, but are reduced with access to additional charging infrastructure. We also find that (1) increasing home charging power above that provided by a common 15 A, 120 V circuit offers little added utility, (2) workplace charging offers significant utility benefits to select high mileage commuters, and (3) broadly available public charging can bring many lower mileage drivers to near-100% utility while strongly increasing the achieved miles of high mileage drivers.

  19. 深水钻井船动力定位时域仿真分析%Time domain simulation analysis of DP for deepwater drillships

    Institute of Scientific and Technical Information of China (English)

    田华勇; 张海彬

    2014-01-01

    Time domain simulation analysis of DP is necessary to obtain the control of the dynamic positioning accuracy. This paper carries out the investigation of the theory and application of SIMO software, and performs the time domain simulation analysis of the dynamic positioning by SIMO. Taking a deepwater drillship as an example, the better calculation results can be obtained by the adjustment of DP control parameter and Kalman gain parameter in order to analyze the influence of the different control the parameters of dynamic positioning. The simulation analysis the process of DP for deepwater drillships which is built up in this paper can provide references for practical application.%时域仿真分析是获得动力定位控制精度的必要手段。文中进行了 SIMO 软件理论和应用方面的研究,基于 SIMO软件建立动力定位能力时域仿真分析流程;以深水钻井船为算例,通过动力定位系统控制参数和 Kalman 增益参数的调整,获得较好的计算结果,并进一步分析了控制参数的不同取值对动力定位能力的影响。文中建立的深水钻井船动力定位能力仿真分析流程可以为工程实践提供参考。

  20. Replacing the wild type loxP site in BACs from the public domain with lox66 using a lox66 transposon

    Directory of Open Access Journals (Sweden)

    Stennett Naima

    2010-02-01

    Full Text Available Abstract Background Chromatin adjoining the site of integration of a transgene affects expression and renders comparisons of closely related transgenes, such as those derived from a BAC deletion series retrofitted with enhancer-traps, unreliable. Gene targeting to a pre-determined site on the chromosome is likely to alleviate the problem. Findings A general procedure to replace the loxP site located at one end of genomic DNA inserts in BACs with lox66 is described. Truncating insert DNA from the loxP end with a Tn10 transposon carrying a lox66 site simultaneously substitutes the loxP with a lox66 sequence. The replacement occurs with high stringency, and the procedure should be applicable to all BACs in the public domain. Cre recombination of loxP with lox66 or lox71 was found to be as efficient as another loxP site during phage P1 transduction of small plasmids containing those sites. However the end-deletion of insert DNA in BACs using a lox66 transposon occurred at no more than 20% the efficiency observed with a loxP transposon. Differences in the ability of Cre protein available at different stages of the P1 life cycle to recombine identical versus non-identical lox-sites is likely responsible for this discrepancy. A possible mechanism to explain these findings is discussed. Conclusions The loxP/lox66 replacement procedure should allow targeting BACs to a pre-positioned lox71 site in zebrafish chromosomes; a system where homologous recombination-mediated "knock-in" technology is unavailable.

  1. Molecular dynamics simulations of Hsp40 J-domain mutants identifies disruption of the critical HPD-motif as the key factor for impaired curing in vivo of the yeast prion [URE3].

    Science.gov (United States)

    Xue, You-Lin; Wang, Hao; Riedy, Michael; Roberts, Brittany-Lee; Sun, Yuna; Song, Yong-Bo; Jones, Gary W; Masison, Daniel C; Song, Youtao

    2017-08-02

    Genetic screens using Saccharomyces cerevisiae have identified an array of Hsp40 (Ydj1p) J-domain mutants that are impaired in the ability to cure the yeast [URE3] prion through disrupting functional interactions with Hsp70. However, biochemical analysis of some of these Hsp40 J-domain mutants has so far failed to provide major insight into the specific functional changes in Hsp40-Hsp70 interactions. To explore the detailed structural and dynamic properties of the Hsp40 J-domain, 20 ns molecular dynamic simulations of 4 mutants (D9A, D36A, A30T, and F45S) and wild-type J-domain were performed, followed by Hsp70 docking simulations. Results demonstrated that although the Hsp70 interaction mechanism of the mutants may vary, the major structural change was targeted to the critical HPD motif of the J-domain. Our computational analysis fits well with previous yeast genetics studies regarding highlighting the importance of J-domain function in prion propagation. During the molecular dynamics simulations several important residues were identified and predicted to play an essential role in J-domain structure. Among these residues, Y26 and F45 were confirmed, using both in silico and in vivo methods, as being critical for Ydj1p function.

  2. An Assessment of Simulation Systems Applicable to Business Process Reengineering at Army Directorates of Public Works

    Science.gov (United States)

    1994-09-01

    available tutorial, I ease of use, and capabilities, PROMODEL is 0 ~~~recommended for use in DPW business process _________________ reerlgineering. 94...capabilities, PROMODEL is recommended for use in DPW business process reengineering. 14. SUBJECT TERMS 15. NUMBER OF PAGES Reengineering Directorates of Public...Works (DPWs) 32 Organizational Change 16. PRICE CODE PROMODEL 17. SECURITY CLASSIFICATION 16. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20

  3. Unraveling the molecular structure of the catalytic domain of matrix metalloproteinase-2 in complex with a triple-helical peptide by means of molecular dynamics simulations.

    Science.gov (United States)

    Díaz, Natalia; Suárez, Dimas; Valdés, Haydeé

    2013-11-26

    Herein, we present the results of a computational study that employed various simulation methodologies to build and validate a series of molecular models of a synthetic triple-helical peptide (fTHP-5) both in its native state and in a prereactive complex with the catalytic domain of the MMP-2 enzyme. First, the structure and dynamical properties of the fTHP-5 substrate are investigated by means of molecular dynamics (MD) simulations. Then, the propensity of each of the three peptide chains in fTHP-5 to be distorted around the scissile peptide bond is assessed by carrying out potential of mean force calculations. Subsequently, the distorted geometries of fTHP-5 are docked within the MMP-2 active site following a semirigid protocol, and the most stable docked structures are fully relaxed and characterized by extensive MD simulations in explicit solvent. Following a similar approach, we also investigate a hypothetical ternary complex formed between two MMP-2 catalytic units and a single fTHP-5 molecule. Overall, our models for the MMP-2/fTHP-5 complexes unveil the extent to which the triple helix is distorted to allow the accommodation of an individual peptide chain within the MMP active site.

  4. Particle-in-Cell simulation of two-dimensional electron velocity shear driven instability in relativistic domain

    CERN Document Server

    Shukla, Chandrasekhar; Patel, Kartik

    2016-01-01

    We carry out Particle-in-Cell (PIC) simulations to study the instabilities associated with a 2-D sheared electron flow configuration against a neutralizing background of ions. Both weak and strong relativistic flow velocities are considered. In the weakly relativistic case, we observe the development of electromagnetic Kelvin Helmholtz instability with similar characteristics as that predicted by the electron Magnetohydrodynamic (EMHD) model. On other hand, in strong relativistic case the compressibility effects of electron fluid dominate and introduce upper hybrid electrostatic oscillations transverse to the flow which are very distinct from EMHD fluid behaviour. In the nonlinear regime, both weak and strong relativistic cases lead to turbulence with broad power law spectrum.

  5. FCS diffusion laws in two-phase lipid membranes: determination of domain mean size by experiments and Monte Carlo simulations.

    Science.gov (United States)

    Favard, Cyril; Wenger, Jérôme; Lenne, Pierre-François; Rigneault, Hervé

    2011-03-02

    Many efforts have been undertaken over the last few decades to characterize the diffusion process in model and cellular lipid membranes. One of the techniques developed for this purpose, fluorescence correlation spectroscopy (FCS), has proved to be a very efficient approach, especially if the analysis is extended to measurements on different spatial scales (referred to as FCS diffusion laws). In this work, we examine the relevance of FCS diffusion laws for probing the behavior of a pure lipid and a lipid mixture at temperatures below, within and above the phase transitions, both experimentally and numerically. The accuracy of the microscopic description of the lipid mixtures found here extends previous work to a more complex model in which the geometry is unknown and the molecular motion is driven only by the thermodynamic parameters of the system itself. For multilamellar vesicles of both pure lipid and lipid mixtures, the FCS diffusion laws recorded at different temperatures exhibit large deviations from pure Brownian motion and reveal the existence of nanodomains. The variation of the mean size of these domains with temperature is in perfect correlation with the enthalpy fluctuation. This study highlights the advantages of using FCS diffusion laws in complex lipid systems to describe their temporal and spatial structure.

  6. A proposed simulation optimization model framework for emergency department problems in public hospital

    Science.gov (United States)

    Ibrahim, Ireen Munira; Liong, Choong-Yeun; Bakar, Sakhinah Abu; Ahmad, Norazura; Najmuddin, Ahmad Farid

    2015-12-01

    The Emergency Department (ED) is a very complex system with limited resources to support increase in demand. ED services are considered as good quality if they can meet the patient's expectation. Long waiting times and length of stay is always the main problem faced by the management. The management of ED should give greater emphasis on their capacity of resources in order to increase the quality of services, which conforms to patient satisfaction. This paper is a review of work in progress of a study being conducted in a government hospital in Selangor, Malaysia. This paper proposed a simulation optimization model framework which is used to study ED operations and problems as well as to find an optimal solution to the problems. The integration of simulation and optimization is hoped can assist management in decision making process regarding their resource capacity planning in order to improve current and future ED operations.

  7. Simulations

    CERN Document Server

    Ngada, N M

    2015-01-01

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  8. Structural refinement of the hERG1 pore and voltage-sensing domains with ROSETTA-membrane and molecular dynamics simulations.

    Science.gov (United States)

    Subbotina, Julia; Yarov-Yarovoy, Vladimir; Lees-Miller, James; Durdagi, Serdar; Guo, Jiqing; Duff, Henry J; Noskov, Sergei Yu

    2010-11-01

    The hERG1 gene (Kv11.1) encodes a voltage-gated potassium channel. Mutations in this gene lead to one form of the Long QT Syndrome (LQTS) in humans. Promiscuous binding of drugs to hERG1 is known to alter the structure/function of the channel leading to an acquired form of the LQTS. Expectably, creation and validation of reliable 3D model of the channel have been a key target in molecular cardiology and pharmacology for the last decade. Although many models were built, they all were limited to pore domain. In this work, a full model of the hERG1 channel is developed which includes all transmembrane segments. We tested a template-driven de-novo design with ROSETTA-membrane modeling using side-chain placements optimized by subsequent molecular dynamics (MD) simulations. Although backbone templates for the homology modeled parts of the pore and voltage sensors were based on the available structures of KvAP, Kv1.2 and Kv1.2-Kv2.1 chimera channels, the missing parts are modeled de-novo. The impact of several alignments on the structure of the S4 helix in the voltage-sensing domain was also tested. Herein, final models are evaluated for consistency to the reported structural elements discovered mainly on the basis of mutagenesis and electrophysiology. These structural elements include salt bridges and close contacts in the voltage-sensor domain; and the topology of the extracellular S5-pore linker compared with that established by toxin foot-printing and nuclear magnetic resonance studies. Implications of the refined hERG1 model to binding of blockers and channels activators (potent new ligands for channel activations) are discussed.

  9. Time-domain simulation of ultrasound propagation in a tissue-like medium based on the resolution of the nonlinear acoustic constitutive relations

    CERN Document Server

    Jiménez, Noé; Redondo, Javier; Sánchez-Morcillo, Víctor; Hou, Yi; Konofagou, Elisa E

    2015-01-01

    A time-domain numerical code based on the constitutive relations of nonlinear acoustics for simulating ultrasound propagation is presented. To model frequency power law attenuation, such as observed in biological media, multiple relaxation processes are included and relaxation parameters are fitted to both exact frequency power law attenuation and empirically measured attenuation of a variety of tissues that does not fit an exact power law. A computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the numerical method and to improve stability when shock waves are present. This technique avoids the use of high order finite difference schemes, leading to fast calculations. The numerical code is especially suitable to study high intensity and focused axisymmetric acoustic beams in tissue-like medium, as it is based on the full constitutive relations that overcomes the limitations of the parabolic approximations, while some specific effects not cont...

  10. Fully nonlinear time-domain simulation of a backward bent duct buoy floating wave energy converter using an acceleration potential method

    Directory of Open Access Journals (Sweden)

    Kyoung-Rok Lee

    2013-12-01

    Full Text Available A floating Oscillating Water Column (OWC wave energy converter, a Backward Bent Duct Buoy (BBDB, was simulated using a state-of-the-art, two-dimensional, fully-nonlinear Numerical Wave Tank (NWT technique. The hydrodynamic performance of the floating OWC device was evaluated in the time domain. The acceleration potential method, with a full-updated kernel matrix calculation associated with a mode decomposition scheme, was implemented to obtain accurate estimates of the hydrodynamic force and displacement of a freely floating BBDB. The developed NWT was based on the potential theory and the boundary element method with constant panels on the boundaries. The mixed Eulerian-Lagrangian (MEL approach was employed to capture the nonlinear free surfaces inside the chamber that interacted with a pneumatic pressure, induced by the time-varying airflow velocity at the air duct. A special viscous damping was applied to the chamber free surface to represent the viscous energy loss due to the BBDB's shape and motions. The viscous damping coefficient was properly selected using a comparison of the experimental data. The calculated surface elevation, inside and outside the chamber, with a tuned viscous damping correlated reasonably well with the experimental data for various incident wave conditions. The conservation of the total wave energy in the computational domain was confirmed over the entire range of wave frequencies.

  11. Molecular Dynamic Simulation to Explore the Molecular Basis of Btk-PH Domain Interaction with Ins(1,3,4,5P4

    Directory of Open Access Journals (Sweden)

    Dan Lu

    2013-01-01

    Full Text Available Bruton’s tyrosine kinase contains a pleckstrin homology domain, and it specifically binds inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5P4, which is involved in the maturation of B cells. In this paper, we studied 12 systems including the wild type and 11 mutants, K12R, S14F, K19E, R28C/H, E41K, L11P, F25S, Y40N, and K12R-R28C/H, to investigate any change in the ligand binding site of each mutant. Molecular dynamics simulations combined with the method of molecular mechanics/Poisson-Boltzmann solvent-accessible surface area have been applied to the twelve systems, and reasonable mutant structures and their binding free energies have been obtained as criteria in the final classification. As a result, five structures, K12R, K19E, R28C/H, and E41K mutants, were classified as “functional mutations,” whereas L11P, S14F, F25S, and Y40N were grouped into “folding mutations.” This rigorous study of the binding affinity of each of the mutants and their classification provides some new insights into the biological function of the Btk-PH domain and related mutation-causing diseases.

  12. Spatial and temporal CCN variations in convection-permitting aerosol microphysics simulations in an idealised marine tropical domain

    Science.gov (United States)

    Planche, Céline; Mann, Graham W.; Carslaw, Kenneth S.; Dalvi, Mohit; Marsham, John H.; Field, Paul R.

    2017-03-01

    A convection-permitting limited area model with periodic lateral boundary conditions and prognostic aerosol microphysics is applied to investigate how concentrations of cloud condensation nuclei (CCN) in the marine boundary layer are affected by high-resolution dynamical and thermodynamic fields. The high-resolution aerosol microphysics-dynamics model, which resolves differential particle growth and aerosol composition across the particle size range, is applied to a domain designed to match approximately a single grid square of a climate model. We find that, during strongly convective conditions with high wind-speed conditions, CCN concentrations vary by more than a factor of 8 across the domain (5-95th percentile range), and a factor of ˜ 3 at more moderate wind speed. One reason for these large sub-climate-grid-scale variations in CCN is that emissions of sea salt and dimethyl sulfide (DMS) are much higher when spatial and temporal wind-speed fluctuations become resolved at this convection-permitting resolution (making peak wind speeds higher). By analysing how the model evolves during spin-up, we gain new insight into the way primary sea salt and secondary sulfate particles contribute to the overall CCN variance in these realistic conditions, and find a marked difference in the variability of super-micron and sub-micron CCN. Whereas the super-micron CCN are highly variable, dominated by strongly fluctuating sea spray emitted, the sub-micron CCN tend to be steadier, mainly produced on longer timescales following growth after new particle formation in the free troposphere, with fluctuations inherently buffered by the fact that coagulation is faster at higher particle concentrations. We also find that sub-micron CCN are less variable in particle size, the accumulation-mode mean size varying by ˜ 20 % (0.101 to 0.123 µm diameter) compared to ˜ 35 % (0.75 to 1.10 µm diameter) for coarse-mode particles at this resolution. We explore how the CCN variability

  13. Spanning the scales of mechanical metamaterials using time domain simulations in transformed crystals, graphene flakes and structured soils.

    Science.gov (United States)

    Aznavourian, Ronald; Puvirajesinghe, Tania M; Brûlé, Stéphane; Enoch, Stefan; Guenneau, Sébastien

    2017-07-25

    We begin with a brief historical survey of discoveries of quasi-crystals and graphene, and then introduce the concept of transformation crystallography, which consists of the application of geometric transforms to periodic structures. We consider motifs with three-fold, four-fold and six-fold symmetries according to the crystallographic restriction theorem. Furthermore, we define motifs with five-fold symmetry such as quasi-crystals generated by a cut-and-projection method from periodic structures in higher-dimensional space. We analyze elastic wave propagation in the transformed crystals and (Penrose-type) quasi-crystals with the finite difference time domain freeware SimSonic. We consider geometric transforms underpinning the design of seismic cloaks with square, circular, elliptical and peanut shapes in the context of honeycomb crystals that can be viewed as scaled-up versions of graphene. Interestingly, the use of morphing techniques leads to the design of cloaks with interpolated geometries reminiscent of Victor Vasarely's artwork. Employing the case of transformed graphene-like (honeycomb) structures allows one to draw useful analogies between large-scale seismic metamaterials such as soils structured with columns of concrete or grout with soil and nanoscale biochemical metamaterials. We further identify similarities in designs of cloaks for elastodynamic and hydrodynamic waves and cloaks for diffusion (heat or mass) processes, as these are underpinned by geometric transforms. Experimental data extracted from field test analysis of soil structured with boreholes demonstrates the application of crystallography to large scale phononic crystals, coined as seismic metamaterials, as they might exhibit low frequency stop bands. This brings us to the outlook of mechanical metamaterials, with control of phonon emission in graphene through extreme anisotropy, attenuation of vibrations of suspension bridges via low frequency stop bands and the concept of transformed

  14. 基于Modelica多领域物理系统云仿真的研究%Cloud Simulation of Multi-domain Physical System based on Modelica

    Institute of Scientific and Technical Information of China (English)

    李耀辉; 张鹏

    2012-01-01

    In order to solve problems such as uncapable of achieving consistency and sharing storage between model library and data resources, uncapable of dividing the functions of modeling and solving as well as improving the optimization of multi-domain simulation, cloud computing concepts and methods are introduced and a multi-domain physical system cloud modeling and simulation platform are established. This paper explains the basic solution process of the platform so as to realize the security sharing, the optimization and reuse of model resources, computing resources and data resources of this system. Finally, feasibility analysis of this system is also made.%为解决难以实现模型库及数据资源的一致性与共享存储、未能实现建模与求解的功能划分以及多领域仿真优化问题求解效率低的问题,引入了云计算理念和方法,建立了多领域物理系统的云端模型及仿真平台,阐述了该平台的基本求解过程,这样可以实现系统中模型资源、计算资源和数据资源的安全共享、优化及重用,并对系统的可行性作出了分析.

  15. Particle-in-cell simulation of two-dimensional electron velocity shear driven instability in relativistic domain

    Science.gov (United States)

    Shukla, Chandrasekhar; Das, Amita; Patel, Kartik

    2016-08-01

    We carry out particle-in-cell simulations to study the instabilities associated with a 2-D sheared electron flow configuration against a neutralizing background of ions. Both weak and strong relativistic flow velocities are considered. In the weakly relativistic case, we observe the development of electromagnetic Kelvin-Helmholtz instability with similar characteristics as that predicted by the electron Magnetohydrodynamic (EMHD) model. On the contrary, in a strong relativistic case, the compressibility effects of electron fluid dominate and introduce upper hybrid electrostatic oscillations transverse to the flow which are very distinct from EMHD fluid behavior. In the nonlinear regime, both weak and strong relativistic cases lead to turbulence with broad power law spectrum.

  16. Domain analysis

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2017-01-01

    The domain-analytic approach to knowledge organization (KO) (and to the broader field of library and information science, LIS) is outlined. The article reviews the discussions and proposals on the definition of domains, and provides an example of a domain-analytic study in the field of art studie....... Varieties of domain analysis as well as criticism and controversies are presented and discussed....

  17. Publicly Open Virtualized Gaming Environment For Simulation of All Aspects Related to '100 Year Starship Study'

    Science.gov (United States)

    Obousy, R. K.

    2012-09-01

    Sending a mission to distant stars will require our civilization to develop new technologies and change the way we live. The complexity of the task is enormous [1] thus, the thought is to involve people from around the globe through the ``citizen scientist'' paradigm. The suggestion is a ``Gaming Virtual Reality Network'' (GVRN) to simulate sociological and technological aspects involved in this project. Currently there is work being done [2] in developing a technology which will construct computer games within GVRN. This technology will provide quick and easy ways for individuals to develop game scenarios related to various aspects of the ``100YSS'' project. People will be involved in solving certain tasks just by play games. Players will be able to modify conditions, add new technologies, geological conditions, social movements and assemble new strategies just by writing scenarios. The system will interface with textual and video information, extract scenarios written in millions of texts and use it to assemble new games. Thus, players will be able to simulate enormous amounts of possibilities. Information technologies will be involved which will require us to start building the system in a way that any modules can be easily replaced. Thus, GVRN should be modular and open to the community.

  18. Time domain simulation of tandem silicon solar cells with optimal textured light trapping enabled by the quadratic complex rational function.

    Science.gov (United States)

    Chung, H; Jung, K-Y; Tee, X T; Bermel, P

    2014-05-05

    Amorphous silicon/crystalline silicon (a-Si/c-Si) micromorph tandem cells, with best confirmed efficiency of 12.3%, have yet to fully approach their theoretical performance limits. In this work, we consider a strategy for improving the light trapping and charge collection of a-Si/c-Si micromorph tandem cells using random texturing with adjustable short-range correlations and long-range periodicity. In order to consider the full-spectrum absorption of a-Si and c-Si, a novel dispersion model known as a quadratic complex rational function (QCRF) is applied to photovoltaic materials (e.g., a-Si, c-Si and silver). It has the advantage of accurately modeling experimental semiconductor dielectric values over the entire relevant solar bandwidth from 300-1000 nm in a single simulation. This wide-band dispersion model is then used to model a silicon tandem cell stack (ITO/a-Si:H/c-Si:H/silver), as two parameters are varied: maximum texturing height h and correlation parameter f. Even without any other light trapping methods, our front texturing method demonstrates 12.37% stabilized cell efficiency and 12.79 mA/cm² in a 2 μm-thick active layer.

  19. Simulating water-quality trends in public-supply wells in transient flow systems.

    Science.gov (United States)

    Jeffrey Starn, J; Green, Christopher T; Hinkle, Stephen R; Bagtzoglou, Amvrossios C; Stolp, Bernard J

    2014-09-01

    Models need not be complex to be useful. An existing groundwater-flow model of Salt Lake Valley, Utah, was adapted for use with convolution-based advective particle tracking to explain broad spatial trends in dissolved solids. This model supports the hypothesis that water produced from wells is increasingly younger with higher proportions of surface sources as pumping changes in the basin over time. At individual wells, however, predicting specific water-quality changes remains challenging. The influence of pumping-induced transient groundwater flow on changes in mean age and source areas is significant. Mean age and source areas were mapped across the model domain to extend the results from observation wells to the entire aquifer to see where changes in concentrations of dissolved solids are expected to occur. The timing of these changes depends on accurate estimates of groundwater velocity. Calibration to tritium concentrations was used to estimate effective porosity and improve correlation between source area changes, age changes, and measured dissolved solids trends. Uncertainty in the model is due in part to spatial and temporal variations in tracer inputs, estimated tracer transport parameters, and in pumping stresses at sampling points. For tracers such as tritium, the presence of two-limbed input curves can be problematic because a single concentration can be associated with multiple disparate travel times. These shortcomings can be ameliorated by adding hydrologic and geologic detail to the model and by adding additional calibration data. However, the Salt Lake Valley model is useful even without such small-scale detail.

  20. La apropiación del dominio público y las posibilidades de acceso a los bienes culturales | The appropriation of the public domain and the possibilities of access to cultural goods

    Directory of Open Access Journals (Sweden)

    Joan Ramos Toledano

    2017-06-01

    Full Text Available Resumen: Las normas de propiedad intelectual y copyright prevén un periodo de protección otorgando unos derechos económicos exclusivos y temporales. Pasado un plazo determinado, las obras protegidas entran en lo que se denomina dominio público. Éste suele ser considerado como el momento en el que los bienes culturales pasan a estar bajo el dominio y control de la sociedad en conjunto. El presente trabajo pretende argumentar que, dado nuestro actual sistema económico, en realidad el dominio público funciona más como una posibilidad de negocio para determinadas empresas que como una verdadera opción para que el público pueda acceder a las obras. Abstract: The legislation of continental intellectual property and copyright provide for a period of protection granting exclusive and temporary economic rights. After a certain period, protected works enter into what is called the public domain. This is often considered as the moment in which the cultural goods come under the control and domain of society as a whole. The present paper pretends to argue that, given our current economic system, the public domain actually functions more as a business opportunity for certain companies than as a real option for the public to access artistic and intellectual works.  

  1. Choice of boundary condition for lattice-Boltzmann simulation of moderate-Reynolds-number flow in complex domains.

    Science.gov (United States)

    Nash, Rupert W; Carver, Hywel B; Bernabeu, Miguel O; Hetherington, James; Groen, Derek; Krüger, Timm; Coveney, Peter V

    2014-02-01

    Modeling blood flow in larger vessels using lattice-Boltzmann methods comes with a challenging set of constraints: a complex geometry with walls and inlets and outlets at arbitrary orientations with respect to the lattice, intermediate Reynolds (Re) number, and unsteady flow. Simple bounce-back is one of the most commonly used, simplest, and most computationally efficient boundary conditions, but many others have been proposed. We implement three other methods applicable to complex geometries [Guo, Zheng, and Shi, Phys. Fluids 14, 2007 (2002); Bouzidi, Firdaouss, and Lallemand, Phys. Fluids 13, 3452 (2001); Junk and Yang, Phys. Rev. E 72, 066701 (2005)] in our open-source application hemelb. We use these to simulate Poiseuille and Womersley flows in a cylindrical pipe with an arbitrary orientation at physiologically relevant Re number (1-300) and Womersley (4-12) numbers and steady flow in a curved pipe at relevant Dean number (100-200) and compare the accuracy to analytical solutions. We find that both the Bouzidi-Firdaouss-Lallemand (BFL) and Guo-Zheng-Shi (GZS) methods give second-order convergence in space while simple bounce-back degrades to first order. The BFL method appears to perform better than GZS in unsteady flows and is significantly less computationally expensive. The Junk-Yang method shows poor stability at larger Re number and so cannot be recommended here. The choice of collision operator (lattice Bhatnagar-Gross-Krook vs multiple relaxation time) and velocity set (D3Q15 vs D3Q19 vs D3Q27) does not significantly affect the accuracy in the problems studied.

  2. Effects of simulation fidelity on user experience in virtual fear of public speaking training - an experimental study.

    Science.gov (United States)

    Poeschl, Sandra; Doering, Nicola

    2014-01-01

    Realistic models in virtual reality training applications are considered to positively influence presence and performance. The experimental study presented, analyzed the effect of simulation fidelity (static vs. animated audience) on presence as a prerequisite for performance in a prototype virtual fear of public speaking application with a sample of N = 40 academic non-phobic users. Contrary to the state of research, no influence was shown on virtual presence and perceived realism, but an animated audience led to significantly higher effects in anxiety during giving a talk. Although these findings could be explained by an application that might not have been realistic enough, they still question the role of presence as a mediating factor in virtual exposure applications.

  3. Fictitious domain methods for elliptic problems with general boundary conditions with an application to the numerical simulation of two phase flows; Methodes de domaine fictif pour des problemes elliptiques avec conditions aux limites generales en vue de la simulation numerique d'ecoulements diphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Ramiere, I

    2006-09-15

    This work is dedicated to the introduction of two original fictitious domain methods for the resolution of elliptic problems (mainly convection-diffusion problems) with general and eventually mixed boundary conditions: Dirichlet, Robin or Neumann. The originality lies in the approximation of the immersed boundary by an approximate interface derived from the fictitious domain Cartesian mesh, which is generally not boundary-fitted to the physical domain. The same generic numerical scheme is used to impose the embedded boundary conditions. Hence, these methods require neither a surface mesh of the immersed boundary nor the local modification of the numerical scheme. We study two modelling of the immersed boundary. In the first one, called spread interface, the approximate immersed boundary is the union of the cells crossed by the physical immersed boundary. In the second one, called thin interface, the approximate immersed boundary lies on sides of mesh cells. Additional algebraic transmission conditions linking both flux and solution jumps through the thin approximate interface are introduced. The fictitious problem to solve as well as the treatment of the embedded boundary conditions are detailed for the two methods. A Q1 finite element scheme is implemented for the numerical validation of the spread interface approach while a new cell-centered finite volume scheme is derived for the thin interface approach with immersed jumps. Each method is then combined to multilevel local mesh refinement algorithms (with solution or flux residual) to increase the precision of the solution in the vicinity of the immersed interface. A convergence analysis of a Q1 finite element method with non-boundary fitted meshes is also presented. This study proves the convergence rates of the present methods. Among the various industrial applications, the simulation on a model of heat exchanger in french nuclear power plants enables us to appreciate the performances of the fictitious domain

  4. Health and economic benefits of public financing of epilepsy treatment in India: An agent-based simulation model.

    Science.gov (United States)

    Megiddo, Itamar; Colson, Abigail; Chisholm, Dan; Dua, Tarun; Nandi, Arindam; Laxminarayan, Ramanan

    2016-03-01

    An estimated 6-10 million people in India live with active epilepsy, and less than half are treated. We analyze the health and economic benefits of three scenarios of publicly financed national epilepsy programs that provide: (1) first-line antiepilepsy drugs (AEDs), (2) first- and second-line AEDs, and (3) first- and second-line AEDs and surgery. We model the prevalence and distribution of epilepsy in India using IndiaSim, an agent-based, simulation model of the Indian population. Agents in the model are disease-free or in one of three disease states: untreated with seizures, treated with seizures, and treated without seizures. Outcome measures include the proportion of the population that has epilepsy and is untreated, disability-adjusted life years (DALYs) averted, and cost per DALY averted. Economic benefit measures estimated include out-of-pocket (OOP) expenditure averted and money-metric value of insurance. All three scenarios represent a cost-effective use of resources and would avert 800,000-1 million DALYs per year in India relative to the current scenario. However, especially in poor regions and populations, scenario 1 (which publicly finances only first-line therapy) does not decrease the OOP expenditure or provide financial risk protection if we include care-seeking costs. The OOP expenditure averted increases from scenarios 1 through 3, and the money-metric value of insurance follows a similar trend between scenarios and typically decreases with wealth. In the first 10 years of scenarios 2 and 3, households avert on average over US$80 million per year in medical expenditure. Expanding and publicly financing epilepsy treatment in India averts substantial disease burden. A universal public finance policy that covers only first-line AEDs may not provide significant financial risk protection. Covering costs for both first- and second-line therapy and other medical costs alleviates the financial burden from epilepsy and is cost-effective across wealth

  5. 基于Modelica多领域建模仿真研究现状与思考%Analysis and Thinking of Application Research Status of Multi-Domain Modeling and Simulation Based on Modelica

    Institute of Scientific and Technical Information of China (English)

    吕有界

    2014-01-01

    Modelica is the declarative modeling language for unified modeling and co-simulation of multi-domain physical system based on equations. Firstly, Modelica language is introduced. Secondly, analysis of application status of multi-domain modeling and simulation based on Modelica is mainly introduced,and multi-domain modeling and simulation of hybrid robots, including its main contents and key technologies, based on Modelica is thought about,which provides effective reference for multi-domain modeling and simulation of hybrid robots.%Modelica 语言是为解决多领域物理系统的统一建模与协同仿真的一种基于方程的陈述式建模语言。对Modelica 语言进行了简单介绍,主要介绍了目前国内利用Modelica 语言进行复杂系统多领域建模与仿真研究现状,并对基于Modelica混联机器人多领域建模与仿真进行了思考,说明了混联机器人多领域建模与仿真的主要内容与关键技术,为混联机器人多领域建模与仿真提供参考。

  6. Domains of quality of life: Results of a three-stage Delphi consensus-procedure amongst patients, family of patients, clinicians, scientists and the general public

    NARCIS (Netherlands)

    Pietersma, S.; de Vries, M.; Akker van den, M.E.

    2014-01-01

    Purpose Our key objective is to identify the core domains of health-related quality of life (QoL). Health-related QoL utility scales are commonly used in economic evaluations to assess the effectiveness of health-care interventions. However, health-care interventions are likely to affect QoL in a

  7. Research and Simulation of Image Filtering Enhancement in Frequency Domain%图像的频域滤波增强研究与仿真

    Institute of Scientific and Technical Information of China (English)

    许艳

    2013-01-01

    Image enhancement is a basic image processing technology. Image enhancement can highlight some information and restrain or remove some unwanted information to improve the quality of image. This paper introduces the image enhancement processing with frequency domain filtering in detail, and carries out simulation experiments using MATLAB. The experimental results show that lowpass filtering can smooth image and remove noise, while highpass filtering can make the image edge or line clear and image sharpening.%图像增强是一种基本的图像处理技术,可以通过突出图像中的某些信息,同时抑制或去除某些不需要的信息来提高图像的质量。文章详细地介绍了图像的频域滤波增强处理,并利用MATLAB进行了仿真实验,实验结果表明:低通滤波可以起到平滑图像、去除噪声的增强作用;高通滤波可使图像的边缘或线条变得清晰,图像得到锐化。

  8. Opening of energy markets: consequences on the missions of public utility and of security of supplies in the domain of electric power and gas; Ouverture des marches energetiques: consequences sur les missions de service public et de securite d'approvisionnement pour l'electricite et le gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This conference was jointly organized by the International Energy Agency (IEA) and the French ministry of economy, finances, and industry (general direction of energy and raw materials, DGEMP). It was organized in 6 sessions dealing with: 1 - the public utility in the domain of energy: definition of the public utility missions, experience feedback about liberalized markets, public utility obligation and pricing regulation; 2 - the new US energy policy and the lessons learnt from the California crisis; 3 - the security of electric power supplies: concepts of security of supplies, opinion of operators, security of power supplies versus liberalization and investments; 4 - security of gas supplies: markets liberalization and investments, long-term contracts and security of supplies; 5 - debate: how to integrate the objectives of public utility and of security of supplies in a competing market; 6 - conclusions. This document brings together the available talks and transparencies presented at the conference. (J.S.)

  9. A Simulation Study on Hypothetical Ebola Virus Transmission in India Using Spatiotemporal Epidemiological Modeler (STEM: A Way towards Precision Public Health

    Directory of Open Access Journals (Sweden)

    Arkaprabha Sau

    2017-01-01

    Full Text Available Background. Precision public health is a state-of-the-art concept in public health research and its application in health care. Application of information technology in field of epidemiology paves the way to its transformation to digital epidemiology. A geospatial epidemiological model was simulated to estimate the spread of Ebola virus disease after a hypothetical outbreak in India. Methods. It was a simulation study based on SEIR (Susceptible-Exposed-Infectious-Recovered compartmental model. Simulation was done in Spatiotemporal Epidemiological Modeler (STEM. Epidemiological profile of Ebola virus, that transmitted throughout the Sierra Leon in 2014–2016, was fitted into the SEIR deterministic compartment model designed for India. Result. Spatiotemporal distribution of EVD exposed, infectious, and recovered population at 4-month interval represented by different figures. It is estimated that if no intervention is taken to stop the spread, within 2 years, almost half of the country will be effected by EVD and cumulative number of exposed individuals, infectious persons, and deaths will be 106947760, 30651674, and 18391005, respectively. Conclusion. Precision public health may play the key role to achieve the health related targets in the Sustainable Development Goals. Policy makers, public health specialists, and data scientists need to put their hands together to make precision public health a reality.

  10. Assessment of CMIP5 global model simulations over the sub-set of CORDEX domains used in the Phase I CREMA

    Science.gov (United States)

    Elguindi, Nellie; Turuncoglu, Ufuk; Giorgi, Filippo

    2013-04-01

    We present an assessment of the CMIP5 global model simulations over a sub-set of CORDEX domains used in the Phase I CREMA (CORDEX RegCM hyper-MAtrix) experiment (Africa, HYMEX-MED (Mediterranean), South America, Central America and West Asia) using three variants of the transformed Mielke measure to assess 1) the model skill in simulating surface temperature and precipitation historical climatology, 2) the degree of surface temperature and precipitation change occurring under greenhouse gas forcing, and 3) the consistency of a model's projected change with that of the Multi Model Ensemble (MME) mean. For precipitation, the highest model skill is found over Africa, and the lowest over Central and South America. Overall, the skill is higher and less variable for temperature than for precipitation. In addition, we find that resolution improves the model skill in the majority of regional and seasonal cases. The largest GHG-induced changes in precipitation occurs over the Mediterranean region, in particular during the summer. The Mediterranean also stands out as having the highest variability in model skill. The least precipitation change occurs over Africa and west Asia. Overall, there is less variability in projected changes of temperature among the models than for precipitation. The greatest temperature changes occur in Central America and the Mediterranean region, while the smallest change occurs in west Asia during winter. Resolution does not have a statistically significant impact on the models' response to GHG forcing which indicates that model biases do not play a primary role in affecting the model response to GHG forcing. All of the UKMO, NOR and NCAR models project precipitation changes which are most similar to the MME, while for temperature this is the case for the NCAR, MPI, CSIRO.AC13 and BCC models. We also assess the three selected models for the CREMA Phase I experiment, HADGEM2ES, MPI-ESMMR and GFDL-ESM2M and find that they are characterized by a

  11. Molecular basis of calcium-sensitizing and desensitizing mutations of the human cardiac troponin C regulatory domain: a multi-scale simulation study.

    Directory of Open Access Journals (Sweden)

    Peter Michael Kekenes-Huskey

    Full Text Available Troponin C (TnC is implicated in the initiation of myocyte contraction via binding of cytosolic Ca²⁺ and subsequent recognition of the Troponin I switch peptide. Mutations of the cardiac TnC N-terminal regulatory domain have been shown to alter both calcium binding and myofilament force generation. We have performed molecular dynamics simulations of engineered TnC variants that increase or decrease Ca²⁺ sensitivity, in order to understand the structural basis of their impact on TnC function. We will use the distinction for mutants that are associated with increased Ca²⁺ affinity and for those mutants with reduced affinity. Our studies demonstrate that for GOF mutants V44Q and L48Q, the structure of the physiologically-active site II Ca²⁺ binding site in the Ca²⁺-free (apo state closely resembled the Ca²⁺-bound (holo state. In contrast, site II is very labile for LOF mutants E40A and V79Q in the apo form and bears little resemblance with the holo conformation. We hypothesize that these phenomena contribute to the increased association rate, k(on, for the GOF mutants relative to LOF. Furthermore, we observe significant positive and negative positional correlations between helices in the GOF holo mutants that are not found in the LOF mutants. We anticipate these correlations may contribute either directly to Ca²⁺ affinity or indirectly through TnI association. Our observations based on the structure and dynamics of mutant TnC provide rationale for binding trends observed in GOF and LOF mutants and will guide the development of inotropic drugs that target TnC.

  12. Simulations of groundwater flow, transport, and age in Albuquerque, New Mexico, for a study of transport of anthropogenic and natural contaminants (TANC) to public-supply wells

    Science.gov (United States)

    Heywood, Charles E.

    2013-01-01

    Vulnerability to contamination from manmade and natural sources can be characterized by the groundwater-age distribution measured in a supply well and the associated implications for the source depths of the withdrawn water. Coupled groundwater flow and transport models were developed to simulate the transport of the geochemical age-tracers carbon-14, tritium, and three chlorofluorocarbon species to public-supply wells in Albuquerque, New Mexico. A separate, regional-scale simulation of transport of carbon-14 that used the flow-field computed by a previously documented regional groundwater flow model was calibrated and used to specify the initial concentrations of carbon-14 in the local-scale transport model. Observations of the concentrations of each of the five chemical species, in addition to water-level observations and measurements of intra-borehole flow within a public-supply well, were used to calibrate parameters of the local-scale groundwater flow and transport models. The calibrated groundwater flow model simulates the mixing of “young” groundwater, which entered the groundwater flow system after 1950 as recharge at the water table, with older resident groundwater that is more likely associated with natural contaminants. Complexity of the aquifer system in the zone of transport between the water table and public-supply well screens was simulated with a geostatistically generated stratigraphic realization based upon observed lithologic transitions at borehole control locations. Because effective porosity was simulated as spatially uniform, the simulated age tracers are more efficiently transported through the portions of the simulated aquifer with relatively higher simulated hydraulic conductivity. Non-pumping groundwater wells with long screens that connect aquifer intervals having different hydraulic heads can provide alternate pathways for contaminant transport that are faster than the advective transport through the aquifer material. Simulation of

  13. Public-key Encryption Based on Extending Discrete Chebyshev Polynomials' Definition Domain to Real Number%基于实数域扩散离散Chebyshev多项式的公钥加密算法

    Institute of Scientific and Technical Information of China (English)

    陈宇; 韦鹏程

    2011-01-01

    将Chebyshev多项式与模运算相结合,对其定义在实数域上进行了扩展,经过理论验证和数据分析,总结出实数域多项式应用于公钥密码的一些性质.利用RSA公钥算法和EIGamal公钥算法的算法结构,提出基于有限域离散Chebyshev多项式的公钥密码算法.该算法结构类似于RSA算法,其安全性基于大数因式分解的难度或者与El-Gamal的离散对数难度相当,能够抵抗对于RSA的选择密文攻击,并且易于软件实现.%By combining Chebyshev polynomials with modulus compute,extending Chebyshev polynomials' definition domain to real number, some conclusions were drawn by theoretic verification and data analysis. Making use of the framework of the traditional public-key algorithm RSA and ElGamal, proposed a chaotic public-key encryption algorithm based on extending discrete Chebyshev polynomials' definition domain to Real number. Its security is based on the intractability of the integer factorization problem as RSA,and it is able to resist the chosen cipher-text attack against RSA and easy to be implemented.

  14. Cannabidiol reduces the anxiety induced by simulated public speaking in treatment-naïve social phobia patients.

    Science.gov (United States)

    Bergamaschi, Mateus M; Queiroz, Regina Helena Costa; Chagas, Marcos Hortes Nisihara; de Oliveira, Danielle Chaves Gomes; De Martinis, Bruno Spinosa; Kapczinski, Flávio; Quevedo, João; Roesler, Rafael; Schröder, Nadja; Nardi, Antonio E; Martín-Santos, Rocio; Hallak, Jaime Eduardo Cecílio; Zuardi, Antonio Waldo; Crippa, José Alexandre S

    2011-05-01

    Generalized Social Anxiety Disorder (SAD) is one of the most common anxiety conditions with impairment in social life. Cannabidiol (CBD), one major non-psychotomimetic compound of the cannabis sativa plant, has shown anxiolytic effects both in humans and in animals. This preliminary study aimed to compare the effects of a simulation public speaking test (SPST) on healthy control (HC) patients and treatment-naïve SAD patients who received a single dose of CBD or placebo. A total of 24 never-treated patients with SAD were allocated to receive either CBD (600 mg; n=12) or placebo (placebo; n=12) in a double-blind randomized design 1 h and a half before the test. The same number of HC (n=12) performed the SPST without receiving any medication. Each volunteer participated in only one experimental session in a double-blind procedure. Subjective ratings on the Visual Analogue Mood Scale (VAMS) and Negative Self-Statement scale (SSPS-N) and physiological measures (blood pressure, heart rate, and skin conductance) were measured at six different time points during the SPST. The results were submitted to a repeated-measures analysis of variance. Pretreatment with CBD significantly reduced anxiety, cognitive impairment and discomfort in their speech performance, and significantly decreased alert in their anticipatory speech. The placebo group presented higher anxiety, cognitive impairment, discomfort, and alert levels when compared with the control group as assessed with the VAMS. The SSPS-N scores evidenced significant increases during the testing of placebo group that was almost abolished in the CBD group. No significant differences were observed between CBD and HC in SSPS-N scores or in the cognitive impairment, discomfort, and alert factors of VAMS. The increase in anxiety induced by the SPST on subjects with SAD was reduced with the use of CBD, resulting in a similar response as the HC.

  15. Predictors of Biased Self-perception in Individuals with High Social Anxiety: The Effect of Self-consciousness in the Private and Public Self Domains.

    Science.gov (United States)

    Nordahl, Henrik; Plummer, Alice; Wells, Adrian

    2017-01-01

    "Biased self-perception," the tendency to perceive one's social performance as more negative than observers do, is characteristic of socially anxious individuals. Self-attention processes are hypothesised to underlie biased self-perception, however, different models emphasise different aspects of self-attention, with attention to the public aspects of the self being prominent. The current study aimed to investigate the relative contribution of two types of dispositional self-attention; public- and private self-consciousness to biased self-perception in a high (n = 48) versus a low (n = 48) social anxiety group undergoing an interaction task. The main finding was that private self-consciousness explained substantial and unique variance in biased negative self-perception in individuals with high social anxiety, while public self-consciousness did not. This relationship was independent of increments in state anxiety. Private self-consciousness appeared to have a specific association with bias related to overestimation of negative social performance rather than underestimation of positive social performance. The implication of this finding is that current treatment models of Social anxiety disorder might include broader aspects of self-focused attention, especially in the context of formulating self-evaluation biases.

  16. Predictors of Biased Self-perception in Individuals with High Social Anxiety: The Effect of Self-consciousness in the Private and Public Self Domains

    Directory of Open Access Journals (Sweden)

    Henrik Nordahl

    2017-07-01

    Full Text Available “Biased self-perception,” the tendency to perceive one’s social performance as more negative than observers do, is characteristic of socially anxious individuals. Self-attention processes are hypothesised to underlie biased self-perception, however, different models emphasise different aspects of self-attention, with attention to the public aspects of the self being prominent. The current study aimed to investigate the relative contribution of two types of dispositional self-attention; public- and private self-consciousness to biased self-perception in a high (n = 48 versus a low (n = 48 social anxiety group undergoing an interaction task. The main finding was that private self-consciousness explained substantial and unique variance in biased negative self-perception in individuals with high social anxiety, while public self-consciousness did not. This relationship was independent of increments in state anxiety. Private self-consciousness appeared to have a specific association with bias related to overestimation of negative social performance rather than underestimation of positive social performance. The implication of this finding is that current treatment models of Social anxiety disorder might include broader aspects of self-focused attention, especially in the context of formulating self-evaluation biases.

  17. Network Hatred:Obstruction and Decomposition of Order Construction in Virtual Public Domain%网络怨恨:虚拟公共领域秩序建构的梗阻与消解

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    网络怨恨既是一种情感体验,也是一种生存状态。越来越多的虚拟社会现象表明,网络怨恨已经出现了一定程度上的弥散,虚拟公共领域秩序建构因而面临着无法回避的现实梗阻。网络怨恨导致无直接利益冲突的网络暴力频现,基于网络民粹主义的阶层对抗遭遇激化,同时网络空间出现颠覆性的价值位移。究其根源,网络怨恨与网络世界的平等理念、现代社会的竞争意识和难以克服的现实困境密切相关。需要通过提升虚拟公共领域的公共理性,适度满足网络怨恨的宣泄需求,构建包容性发展的网络监督体系,纠正虚拟公共领域中的价值位移等途径,才能真正消解网络怨恨,实现虚拟公共领域的秩序化运行。%Network hatred is not only an emotional experience , but also a living state.It is suggested by more and more virtual social phenomenon that network hatred has been dispersing in the new public domain and has become virtual social emotions in the keynote.Thus, order construction in the virtual public domain has been ex-posed to practical obstructions which cannot be evaded.As a result of network hatred , network violence , which has no direct conflict of interests , frequently shows up , and network populism-based hierarchical confrontation is triggered , and concurrently , subversive value displacement shows up in network space.Tracing to the source , network hatred is closely related to the equality philosophy of network world , the sense of competition in the modern society and the insurmountable practical difficulties.Only by such channels as improving public reason of the virtual public domain , moderately satisfying the needs for unbosoming network hatred , constructing net-work supervision system under inclusive development and correcting value displacement in the virtual public do -main, can network hatred be truly decomposed and regularized operation of the

  18. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable p...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used.......Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...

  19. L'apprentissage des langues médiatisé par les technologies (ALMT – Étude d'un domaine de recherche émergent à travers les publications de la revue Alsic Technology-mediated language learning: an emergent research domain under study through the review of a French scientific journal's publications

    Directory of Open Access Journals (Sweden)

    Nicolas Guichon

    2012-11-01

    Full Text Available Dans cette étude, il est postulé que l'apprentissage des langues médiatisé par les technologies (ALMT est un domaine de recherche qui s'intéresse au développement et à l'intégration des technologies dans l'enseignement-apprentissage d'une langue. Ce domaine étant émergent, la présente recherche vise tout d'abord à comprendre comment s'est formée la communauté de chercheurs autour de cet objet. Puis, à travers l'analyse critique de 79 articles publiés dans la revue en ligne francophone Alsic entre 1998 et 2010, la présente contribution s'emploie à définir les contours épistémologiques de ce domaine en étudiant les moyens de production de connaissance.In this study, it is postulated that technology mediated language learning is a research domain that focuses on the design and integration of technologies for language learning and teaching. Because this domain is emergent, the present study first aims at understanding how a community of researchers has developed around this object. Then, thanks to the critical analysis of 79 articles published in Alsic, a French-speaking online journal, the present article endeavours to define the epistemological contours of this research domain by studying the means employed to produce knowledge.

  20. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  1. Monte Carlo Simulation Of Emission Tomography And Other Medical Imaging Techniques

    Science.gov (United States)

    Harrison, Robert L.

    2010-01-01

    An introduction to Monte Carlo simulation of emission tomography. This paper reviews the history and principles of Monte Carlo simulation, then applies these principles to emission tomography using the public domain simulation package SimSET (a Simulation System for Emission Tomography) as an example. Finally, the paper discusses how the methods are modified for X-ray computed tomography and radiotherapy simulations. PMID:20733931

  2. Experience Report: Constraint-Based Modelling and Simulation of Railway Emergency Response Plans

    DEFF Research Database (Denmark)

    Debois, Søren; Hildebrandt, Thomas; Sandberg, Lene

    2016-01-01

    We report on experiences from a case study applying a constraint-based process-modelling and -simulation tool, dcrgraphs.net, to the modelling and rehearsal of railway emergency response plans with domain experts. The case study confirmed the approach as a viable means for domain experts to analyse...... and security processes in the danish public transport sector and their dependency on ICT....

  3. Molecular modeling and molecular dynamic simulation of the effects of variants in the TGFBR2 kinase domain as a paradigm for interpretation of variants obtained by next generation sequencing.

    Science.gov (United States)

    Zimmermann, Michael T; Urrutia, Raul; Oliver, Gavin R; Blackburn, Patrick R; Cousin, Margot A; Bozeck, Nicole J; Klee, Eric W

    2017-01-01

    Variants in the TGFBR2 kinase domain cause several human diseases and can increase propensity for cancer. The widespread application of next generation sequencing within the setting of Individualized Medicine (IM) is increasing the rate at which TGFBR2 kinase domain variants are being identified. However, their clinical relevance is often uncertain. Consequently, we sought to evaluate the use of molecular modeling and molecular dynamics (MD) simulations for assessing the potential impact of variants within this domain. We documented the structural differences revealed by these models across 57 variants using independent MD simulations for each. Our simulations revealed various mechanisms by which variants may lead to functional alteration; some are revealed energetically, while others structurally or dynamically. We found that the ATP binding site and activation loop dynamics may be affected by variants at positions throughout the structure. This prediction cannot be made from the linear sequence alone. We present our structure-based analyses alongside those obtained using several commonly used genomics-based predictive algorithms. We believe the further mechanistic information revealed by molecular modeling will be useful in guiding the examination of clinically observed variants throughout the exome, as well as those likely to be discovered in the near future by clinical tests leveraging next-generation sequencing through IM efforts.

  4. A Secure Public-key Image Authentication Plan

    Institute of Scientific and Technical Information of China (English)

    YANG Qing; CHEN Ke-fei

    2005-01-01

    Digital watermark can be used for image ownership verification or authentication. In this paper, we propose a new image authentication plan concentrating on its security performance. Digital watermark is first turbo coded, scaled and then processed in wavelet domain. To enhance security level, public key cryptosystem is utilized to replace traditional watermark key. Simulation results are finally given by experiment.

  5. [Design and study of parallel computing environment of Monte Carlo simulation for particle therapy planning using a public cloud-computing infrastructure].

    Science.gov (United States)

    Yokohama, Noriya

    2013-07-01

    This report was aimed at structuring the design of architectures and studying performance measurement of a parallel computing environment using a Monte Carlo simulation for particle therapy using a high performance computing (HPC) instance within a public cloud-computing infrastructure. Performance measurements showed an approximately 28 times faster speed than seen with single-thread architecture, combined with improved stability. A study of methods of optimizing the system operations also indicated lower cost.

  6. Trusted Domain

    DEFF Research Database (Denmark)

    Hjorth, Theis Solberg; Torbensen, Rune

    2012-01-01

    that enables secure end-to-end communication with home automation devices, and it supports device revocations as well as a structure of intersecting sets of nodes for scalability. Devices in the Trusted Domain are registered in a list that is distributed using a robust epidemic protocol optimized...

  7. Domain crossing

    DEFF Research Database (Denmark)

    Schraefel, M. C.; Rouncefield, Mark; Kellogg, Wendy

    2012-01-01

    In CSCW, how much do we need to know about another domain/culture before we observe, intersect and intervene with designs. What optimally would that other culture need to know about us? Is this a “how long is a piece of string” question, or an inquiry where we can consider a variety of contexts a...

  8. The visible ear simulator: a public PC application for GPU-accelerated haptic 3D simulation of ear surgery based on the visible ear data

    DEFF Research Database (Denmark)

    Sørensen, Mads Sølvsten; Mosegaard, Jesper; Trier, Peter

    2009-01-01

    BACKGROUND: Existing virtual simulators for middle ear surgery are based on 3-dimensional (3D) models from computed tomographic or magnetic resonance imaging data in which image quality is limited by the lack of detail (maximum, approximately 50 voxels/mm3), natural color, and texture of the sour...

  9. Simulation of homology models for the extracellular domains (ECD) of ErbB3, ErbB4 and the ErbB2-ErbB3 complex in their active conformations.

    Science.gov (United States)

    Franco-Gonzalez, Juan Felipe; Ramos, Javier; Cruz, Victor L; Martínez-Salazar, Javier

    2013-02-01

    Epidermal growth factor receptors (EGFR) are associated with a number of biological processes and are becoming increasingly recognized as important therapeutic targets against cancer. In this work, we provide models based on homology for the extracellular domains (ECD) of ErbB3 and ErbB4 in their active conformations, including a Heregulin ligand, followed by further refinement of the models by molecular dynamics simulations at atomistic scale. We compare the results with a model built for ErbB2 based on crystallographic information and analyze the common features observed among members of the family, namely, the periscope movement of the dimerization arm and the hinge displacement of domain IV. Finally, we refine a model for the interaction of the ECDs corresponding to a ErbB2-ErbB3 heterodimer, which is widely recognized to have a high impact in cancer development.

  10. Mapping Knowledge Domain on Subject Headings of Public Sentiment Research Based on Multi-dimensional Scaling%基于多维尺度分析的舆情研究主题词知识图谱

    Institute of Scientific and Technical Information of China (English)

    孙艳; 田丽梅

    2016-01-01

    为了对舆情的研究现状进行客观梳理,总结研究文献内在的联系和科学结构,文中选取近5年来中国知网收录的“中文核心期刊”和“CSSCI”相关研究文献展开研究。首先,进行前期数据准备,包括准备的步骤与方法及其相关的数学模型;然后,将相异系数矩阵输入到SPSS中进行多维尺度分析并绘制知识图谱;最后,从维度定义和空间分布特点两个方面对知识图谱进行分析。结果表明,当前舆情研究主要集中于4个方向,舆情直接相关研究是重点与热点,媒体相关的研究领域也较活跃,但一些细分的研究方向成果比较分散。%In order to conduct objective comb for the current situation of public sentiment research and summarize the intrinsic links and science structure of researched literatures,it researches on"Chinese Core Journals" and"CSSCI" relevant research literatures included in CNKI in the past five years in this paper. First,preliminary data should be prepared,comprising the steps and methods of preparation and associated mathematical model. Then,the dissimilarity coefficient matrix is input into SPSS software to carry on multi dimensional scaling and draw mapping knowledge domain. Finally,mapping knowledge domain must be analyzed from two aspects of dimension definition and spatial distribution. The results show that the current public sentiment research has focused on four directions,and direct relevant re-search of public sentiment is the focus and hotspot,and media-related field of study is more active,but some results of research direction of segmentation are more dispersed.

  11. The Time & Frequency Domain Model and Simulation Analysis on Simulink of DSB Communication System%DSB通信系统的Simulink时域频域模型与仿真分析

    Institute of Scientific and Technical Information of China (English)

    刘婷婷; 杨云

    2013-01-01

    基于Matlab的Simulink仿真平台,研究了单频信号下DSB通信系统的传输原理,提出了一种新的DSB通信系统时域频域模型并进行仿真。仿真结果表明,通过该模型的信号特性能够与理论分析保持一致,符合DSB通信系统的要求,并且能够同时观察信号的信号波形与频谱结构,为更深一步的理论研究和分析提供了更加便利的环境。%Simulink simulation platform based on the Matla, the DSB communication system under the single-frequency signal transmission principle is researched, this paper proposes a new DSB communication system time domain and fre-quency domain model and carries on the simulation. Simulation results show that get through the signal characteristics of the model can be consistent with the theoretical analysis, accord with the requirement of DSB communication system, and can be observed signal of the signal waveform and spectrum structure at the same time, for a further theoretical research and analysis provided a more convenient environment.

  12. Inherent dynamics of head domain correlates with ATP-recognition of P2X4 receptors: insights gained from molecular simulations.

    Directory of Open Access Journals (Sweden)

    Li-Dong Huang

    Full Text Available P2X receptors are ATP-gated ion channels involved in many physiological functions, and determination of ATP-recognition (AR of P2X receptors will promote the development of new therapeutic agents for pain, inflammation, bladder dysfunction and osteoporosis. Recent crystal structures of the zebrafish P2X4 (zfP2X4 receptor reveal a large ATP-binding pocket (ABP located at the subunit interface of zfP2X4 receptors, which is occupied by a conspicuous cluster of basic residues to recognize triphosphate moiety of ATP. Using the engineered affinity labeling and molecular modeling, at least three sites (S1, S2 and S3 within ABP have been identified that are able to recognize the adenine ring of ATP, implying the existence of at least three distinct AR modes in ABP. The open crystal structure of zfP2X4 confirms one of three AR modes (named AR1, in which the adenine ring of ATP is buried into site S1 while the triphosphate moiety interacts with clustered basic residues. Why architecture of ABP favors AR1 not the other two AR modes still remains unexplored. Here, we examine the potential role of inherent dynamics of head domain, a domain involved in ABP formation, in AR determinant of P2X4 receptors. In silico docking and binding free energy calculation revealed comparable characters of three distinct AR modes. Inherent dynamics of head domain, especially the downward motion favors the preference of ABP for AR1 rather than AR2 and AR3. Along with the downward motion of head domain, the closing movement of loop139-146 and loop169-183, and structural rearrangements of K70, K72, R298 and R143 enabled ABP to discriminate AR1 from other AR modes. Our observations suggest the essential role of head domain dynamics in determining AR of P2X4 receptors, allowing evaluation of new strategies aimed at developing specific blockers/allosteric modulators by preventing the dynamics of head domain associated with both AR and channel activation of P2X4 receptors.

  13. Structural, stability, dynamic and binding properties of the ALS-causing T46I mutant of the hVAPB MSP domain as revealed by NMR and MD simulations.

    Directory of Open Access Journals (Sweden)

    Shixiong Lua

    Full Text Available T46I is the second mutation on the hVAPB MSP domain which was recently identified from non-Brazilian kindred to cause a familial amyotrophic lateral sclerosis (ALS. Here using CD, NMR and molecular dynamics (MD simulations, we characterized the structure, stability, dynamics and binding capacity of the T46I-MSP domain. The results reveal: 1 unlike P56S which we previously showed to completely eliminate the native MSP structure, T46I leads to no significant disruption of the native secondary and tertiary structures, as evidenced from its far-UV CD spectrum, as well as Cα and Cβ NMR chemical shifts. 2 Nevertheless, T46I does result in a reduced thermodynamic stability and loss of the cooperative urea-unfolding transition. As such, the T46I-MSP domain is more prone to aggregation than WT at high protein concentrations and temperatures in vitro, which may become more severe in the crowded cellular environments. 3 T46I only causes a 3-fold affinity reduction to the Nir2 peptide, but a significant elimination of its binding to EphA4. 4 EphA4 and Nir2 peptide appear to have overlapped binding interfaces on the MSP domain, which strongly implies that two signaling networks may have a functional interplay in vivo. 5 As explored by both H/D exchange and MD simulations, the MSP domain is very dynamic, with most loop residues and many residues on secondary structures highly fluctuated or/and exposed to bulk solvent. Although T46I does not alter overall dynamics, it does trigger increased dynamics of several local regions of the MSP domain which are implicated in binding to EphA4 and Nir2 peptide. Our study provides the structural and dynamic understanding of the T46I-causing ALS; and strongly highlights the possibility that the interplay of two signaling networks mediated by the FFAT-containing proteins and Eph receptors may play a key role in ALS pathogenesis.

  14. Simulations of Ground-Water Flow and Particle Pathline Analysis in the Zone of Contribution of a Public-Supply Well in Modesto, Eastern San Joaquin Valley, California

    Science.gov (United States)

    Burow, Karen R.; Jurgens, Bryant C.; Kauffman, Leon J.; Phillips, Steven P.; Dalgish, Barbara A.; Shelton, Jennifer L.

    2008-01-01

    Shallow ground water in the eastern San Joaquin Valley is affected by high nitrate and uranium concentrations and frequent detections of pesticides and volatile organic compounds (VOC), as a result of ground-water development and intensive agricultural and urban land use. A single public-supply well was selected for intensive study to evaluate the dominant processes affecting the vulnerability of public-supply wells in the Modesto area. A network of 23 monitoring wells was installed, and water and sediment samples were collected within the approximate zone of contribution of the public-supply well, to support a detailed analysis of physical and chemical conditions and processes affecting the water chemistry in the well. A three-dimensional, steady-state local ground-water-flow and transport model was developed to evaluate the age of ground water reaching the well and to evaluate the vulnerability of the well to nonpoint source input of nitrate and uranium. Particle tracking was used to compute pathlines and advective travel times in the ground-water flow model. The simulated ages of particles reaching the public-supply well ranged from 9 to 30,000 years, with a median of 54 years. The age of the ground water contributed to the public-supply well increased with depth below the water table. Measured nitrate concentrations, derived primarily from agricultural fertilizer, were highest (17 milligrams per liter) in shallow ground water and decreased with depth to background concentrations of less than 2 milligrams per liter in the deepest wells. Because the movement of water is predominantly downward as a result of ground-water development, and because geochemical conditions are generally oxic, high nitrate concentrations in shallow ground water are expected to continue moving downward without significant attenuation. Simulated long-term nitrate concentrations indicate that concentrations have peaked and will decrease in the public-supply well during the next 100 years

  15. Structural models of zebrafish (Danio rerio NOD1 and NOD2 NACHT domains suggest differential ATP binding orientations: insights from computational modeling, docking and molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Jitendra Maharana

    Full Text Available Nucleotide-binding oligomerization domain-containing protein 1 (NOD1 and NOD2 are cytosolic pattern recognition receptors playing pivotal roles in innate immune signaling. NOD1 and NOD2 recognize bacterial peptidoglycan derivatives iE-DAP and MDP, respectively and undergoes conformational alternation and ATP-dependent self-oligomerization of NACHT domain followed by downstream signaling. Lack of structural adequacy of NACHT domain confines our understanding about the NOD-mediated signaling mechanism. Here, we predicted the structure of NACHT domain of both NOD1 and NOD2 from model organism zebrafish (Danio rerio using computational methods. Our study highlighted the differential ATP binding modes in NOD1 and NOD2. In NOD1, γ-phosphate of ATP faced toward the central nucleotide binding cavity like NLRC4, whereas in NOD2 the cavity was occupied by adenine moiety. The conserved 'Lysine' at Walker A formed hydrogen bonds (H-bonds and Aspartic acid (Walker B formed electrostatic interaction with ATP. At Sensor 1, Arg328 of NOD1 exhibited an H-bond with ATP, whereas corresponding Arg404 of NOD2 did not. 'Proline' of GxP motif (Pro386 of NOD1 and Pro464 of NOD2 interacted with adenine moiety and His511 at Sensor 2 of NOD1 interacted with γ-phosphate group of ATP. In contrast, His579 of NOD2 interacted with the adenine moiety having a relatively inverted orientation. Our findings are well supplemented with the molecular interaction of ATP with NLRC4, and consistent with mutagenesis data reported for human, which indicates evolutionary shared NOD signaling mechanism. Together, this study provides novel insights into ATP binding mechanism, and highlights the differential ATP binding modes in zebrafish NOD1 and NOD2.

  16. Simulation of seismic wave propagation in 2-D poroelastic media using weighted-averaging finite difference stencils in the frequency-space domain

    Science.gov (United States)

    Yang, Qingjie; Mao, Weijian

    2017-01-01

    The poroelastodynamic equations are used to describe the dynamic solid-fluid interaction in the reservoir. To obtain the intrinsic properties of reservoir rocks from geophysical data measured in both laboratory and field, we need an accurate solution of the wave propagation in porous media. At present, the poroelastic wave equations are mostly solved in the time domain, which involves a difficult and complicated time convolution. In order to avoid the issues caused by the time convolution, we propose a frequency-space domain method. The poroelastic wave equations are composed of a linear system in the frequency domain, which easily takes into account the effects of all frequencies on the dispersion and attenuation of seismic wave. A 25-point weighted-averaging finite different scheme is proposed to discretize the equations. For the finite model, the perfectly matched layer technique is applied at the model boundaries. We validated the proposed algorithm by testing three numerical examples of poroelastic models, which are homogenous, two-layered and heterogeneous with different fluids, respectively. The testing results are encouraging in the aspects of both computational accuracy and efficiency.

  17. Modeling and Simulation of Current Source Inverter Fed Synchronous Motor in Complex Frequency Domain Taking the Transition Zone From Induction Motor to Synchronous Motor Mode into Account

    Directory of Open Access Journals (Sweden)

    A.B. Chattopadhyay

    2014-02-01

    Full Text Available Modeling of synchronous motor plays a dominant role in designing complicated drive system for different applications, especially large blower fans etc for steel industries. As synchronous motor has no inherent starting torque generally it is started as an induction motor with the help of a damper winding and it pulls into synchronism under certain conditions. The present paper exactly concentrates on this particular zone of transition from induction motor to synchronous motor mode for a current source inverter fed synchronous motor drive system. Due to complexity of synchronous motor in terms of number of windings and finite amount of air gap saliency, direct modeling of such transition zone in time domain becomes cumbersome at the first instance of modeling. That is why the modeling in complex frequency domain (s-domain has been taken up using small perturbation model. Such a model clearly shows role of induction motor as noise function or disturbance function with respect to the open loop block diagram of synchronous motor. Such finding can be quantized in terms of important results and that is done in the present paper such that the results can help the designer for the successful design of a synchronous motor drive system.

  18. GIPL1.3 simulated mean annual ground temperature (MAGT) in Celsius averaged for particular decade for the entire Alaskan permafrost domain. NAD83, Alaska Albers projection

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — This raster, created in 2010, is output from the Geophysical Institute Permafrost Lab (GIPL) model and represents simulated mean annual ground temperature (MAGT) in...

  19. GIPL1.3 simulated maximum active layer thickness (ALT) in meters averaged for particular decade for the entire Alaskan permafrost domain. NAD83, Alaska Albers projection

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — This raster, created in 2010, is output from the Geophysical Institute Permafrost Lab (GIPL) model and represents simulated active layer thickness (ALT) in meters...

  20. A domain-specific analysis system for examining nuclear reactor simulation data for light-water and sodium-cooled fast reactors

    OpenAIRE

    Billings, Jay Jay; Deyton, Jordan H.; Hull, S. Forest; Lingerfelt, Eric J.; Wojtowicz, Anna

    2014-01-01

    Building a new generation of fission reactors in the United States presents many technical and regulatory challenges. One important challenge is the need to share and present results from new high-fidelity, high-performance simulations in an easily usable way. Since modern multiscale, multi-physics simulations can generate petabytes of data, they will require the development of new techniques and methods to reduce the data to familiar quantities of interest (e.g., pin powers, temperatures) wi...

  1. Modeling rational, psychological, and social behavior toward diffusion of new technology using agent-based simulation: the case of the public utility jeepney (PUJ) fleet in Metro Manila

    DEFF Research Database (Denmark)

    Ahanchian, Mohammad; Biona, Jose Bienvenido Manuel

    2017-01-01

    is to assist policymakers for energy and environmental policy design based on consumers’ behavior. The jeepney owners in the old public utility jeepney (PUJ) fleet in Metro Manila are chosen as case study to prove the applicability of the model. The results show that rational, psychological, and social...... configuration affect diffusion of innovation. This study presents an agent-based model (ABM) to simulate the rational decision-making, psychological behavior, and social interaction of people to explore their reaction to policy scenarios toward adopting technological changes over time. The aim of model...

  2. Simulation and Performance Analysis of Lithium Battery Bank Mounted on the Hybrid Power System for Mobile Public Health Center

    Science.gov (United States)

    Busono, Pratondo; Kartini, Evvy

    2013-07-01

    Mobile medical clinic has been proposed to serve homeless people, people in the disaster area or in the remote area where no health service exist. At that site, a number of essential services such as primary health care, general health screening, medical treatment and emergency/rescue operations are required. Such services usually requires on board electrical equipments such as refrigerators, komputer, power tools and medical equipments. To supply such electrical equipments, it needs extra auxiliary power sources, in addition of standard automotive power supply. The auxiliary power source specifically design to supply non automotive load which may have similar configuration, but usually uses high power alternator rated and larger deep cycle on board battery bank. This study covers the modeling and dynamic simulation of auxiliary power source/battery to supply the medical equipment and other electrical equipments on board. It consists a variable speed diesel generator set, photovoltaic (PV) generator mounted on the roof of the car, a rechargable battery bank. As an initial step in the system design, a simulation study was performed. The simulation is conducted in the system level. Simulation results shows that dynamical behaviour by means of current density, voltage and power plot over a chosen time range, and functional behaviour such as charging and discharging characteristic of the battery bank can be obtained.

  3. Simulations of Groundwater Flow and Particle Tracking Analysis in the Area Contributing Recharge to a Public-Supply Well near Tampa, Florida, 2002-05

    Science.gov (United States)

    Crandall, Christy A.; Kauffman, Leon J.; Katz, Brian G.; Metz, Patricia A.; McBride, W. Scott; Berndt, Marian P.

    2009-01-01

    Shallow ground water in the north-central Tampa Bay region, Florida, is affected by elevated nitrate concentrations, the presence of volatile organic compounds, and pesticides as a result of groundwater development and intensive urban land use. The region relies primarily on groundwater for drinking-water supplies. Sustainability of groundwater quality for public supply requires monitoring and understanding of the mechanisms controlling the vulnerability of public-supply wells to contamination. A single public-supply well was selected for intensive study based on the need to evaluate the dominant processes affecting the vulnerability of public-supply wells in the Upper Floridan aquifer in the City of Temple Terrace near Tampa, Florida, and the presence of a variety of chemical constituents in water from the well. A network of 29 monitoring wells was installed, and water and sediment samples were collected within the area contributing recharge to the selected public-supply well to support a detailed analysis of physical and chemical conditions and processes affecting the water chemistry in the well. A three-dimensional, steady-state groundwater flow model was developed to evaluate the age of groundwater reaching the well and to test hypotheses on the vulnerability of the well to nonpoint source input of nitrate. Particle tracking data were used to calculate environmental tracer concentrations of tritium and sulfur hexafluoride and to calibrate traveltimes and compute flow paths and advective travel times in the model area. The traveltime of particles reaching the selected public-supply well ranged from less than 1 day to 127.0 years, with a median of 13.1 years; nearly 45 percent of the simulated particle ages were less than about 10 years. Nitrate concentrations, derived primarily from residential/commercial fertilizer use and atmospheric deposition, were highest (2.4 and 6.11 milligrams per liter as nitrogen, median and maximum, respectively) in shallow

  4. Audibility of dispersion error in room acoustic finite-difference time-domain simulation in the presence of absorption of air.

    Science.gov (United States)

    Saarelma, Jukka; Savioja, Lauri

    2016-12-01

    The finite-difference time-domain method has gained increasing interest for room acoustic prediction use. A well-known limitation of the method is a frequency and direction dependent dispersion error. In this study, the audibility of dispersion error in the presence of air absorption is measured. The results indicate that the dispersion error in the worst-case direction of the studied scheme gets masked by the air absorption at a phase velocity error percentage of 0.28% at the frequency of 20 kHz.

  5. Computer simulations suggest direct and stable tip to tip interaction between the outer membrane channel TolC and the isolated docking domain of the multidrug RND efflux transporter AcrB.

    Science.gov (United States)

    Schmidt, Thomas H; Raunest, Martin; Fischer, Nadine; Reith, Dirk; Kandt, Christian

    2016-07-01

    One way by which bacteria achieve antibiotics resistance is preventing drug access to its target molecule for example through an overproduction of multi-drug efflux pumps of the resistance nodulation division (RND) protein super family of which AcrAB-TolC in Escherichia coli is a prominent example. Although representing one of the best studied efflux systems, the question of how AcrB and TolC interact is still unclear as the available experimental data suggest that either both proteins interact in a tip to tip manner or do not interact at all but are instead connected by a hexamer of AcrA molecules. Addressing the question of TolC-AcrB interaction, we performed a series of 100 ns - 1 µs-molecular dynamics simulations of membrane-embedded TolC in presence of the isolated AcrB docking domain (AcrB(DD)). In 5/6 simulations we observe direct TolC-AcrB(DD) interaction that is only stable on the simulated time scale when both proteins engage in a tip to tip manner. At the same time we find TolC opening and closing freely on extracellular side while remaining closed at the inner periplasmic bottleneck region, suggesting that either the simulated time is too short or additional components are required to unlock TolC.

  6. The block cipher NSABC (public domain)

    CERN Document Server

    Nguyenova-Stepanikova, Alice

    2011-01-01

    We introduce NSABC/w -- Nice-Structured Algebraic Block Cipher using w-bit word arithmetic, a 4w-bit analogous of Skipjack [NSA98] with 5w-bit key. The Skipjack's internal 4-round Feistel structure is replaced with a w-bit, 2-round cascade of a binary operation (x,z)\\mapsto(x\\boxdot z)\\lll(w/2) that permutes a text word x under control of a key word z. The operation \\boxdot, similarly to the multiplication in IDEA [LM91, LMM91], bases on an algebraic group over w-bit words, so it is also capable of decrypting by means of the inverse element of z in the group. The cipher utilizes a secret 4w-bit tweak -- an easily changeable parameter with unique value for each block encrypted under the same key [LRW02] -- that is derived from the block index and an additional 4w -bit key. A software implementation for w=64 takes circa 9 clock cycles per byte on x86-64 processors.

  7. 22 CFR 120.11 - Public domain.

    Science.gov (United States)

    2010-04-01

    .... Government and specific access and dissemination controls protecting information resulting from the research... published information; (3) Through second class mailing privileges granted by the U.S. Government; (4) At.... Government access and dissemination controls. University research will not be considered fundamental...

  8. Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication

    Directory of Open Access Journals (Sweden)

    Chang Kyu Sung

    2016-01-01

    Full Text Available Purpose: The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI by using an electrical circuit model to simulate renal blood flow. Methods: In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff’s current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. Results: Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. Conclusion: This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

  9. Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication)

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Chang Kyu [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Han, Bong Soo [Dept. of Radiological Science, College of Health Science, Yonsei University, Wonju (Korea, Republic of); Kim, Seung Hyup [Dept. of Radiology, Institute of Radiation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-01-15

    The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI) by using an electrical circuit model to simulate renal blood flow. In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff’s current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research) and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

  10. Multiscale simulation of nanometric cutting of single crystal Cu based on bridging domain method%基于桥域理论的Cu单晶纳米切削跨尺度仿真研究

    Institute of Scientific and Technical Information of China (English)

    梁迎春; 盆洪民; 白清顺; 卢礼华

    2011-01-01

    One of the significant methods of multiscale simulation named bridging domain method which is a mixed atomistic-continuum formulation is reviewed.The mode related to atomistic/continuum coupling is introduced.The coupled method with the treatment of the overlapping subdomain is discussed,in which different scaling parameters(weigh factors) are adopted to calculate the energy of the system in the overlapping subdomain and to constrain the atomic and the continuum displacements by the Lagrange multiplier method.A bridging domain model is set up to investigate the effect of cutting speed on chip and workpiece atom force distribution in the nanometric cutting of single crystal copper.Simulation results show the cutting deformation coefficient decreases and the workpiece atom force increases with the increase of cutting speed.In addition,the machined surface qualities at different cutting speeds are investigated.The multiscale model and simulation of nanometric cutting are accomplished based on the bridging domain method,which lays a theoretical foundation for exploring the trans-scale simulation of nanometric cutting.%桥域方法是一种典型的跨尺度仿真研究方法.基于桥域理论,本文分析了原子和连续介质耦合区域的处理问题,即在耦合区采用不同的权重计算系统的能量,通过Lagrange乘子法对原子和连续介质位移进行约束.采用桥域方法,建立了单晶Cu米纳切削的跨尺度仿真模型,获得了单晶Cu纳米切削的材料变形机理.同时,研究了不同切削速度对纳米切削过程和原子受力分布的影响,仿真结果表明:随着切削速度的提高,切削区原子所受的力值增大,切屑变形系数减小,已加工表面变质层厚度增加.本文基于桥域理论,实现了Cu单晶纳米切削跨尺度的建模和仿真,为探索纳米切削的跨尺度仿真研究提供理论基础.

  11. Simulation of the effects of seasonally varying pumping on intraborehole flow and the vulnerability of public-supply wells to contamination.

    Science.gov (United States)

    Yager, Richard M; Heywood, Charles E

    2014-09-01

    Public-supply wells with long screens in alluvial aquifers can produce waters of differing quality from different depths. Seasonal changes in quality are linked to seasonal changes in pumping rates that influence the distribution of flow into the well screens under pumping conditions and the magnitude and direction of intraborehole flow within the wells under ambient conditions. Groundwater flow and transport simulations with MODFLOW and MT3DMS were developed to quantify the effects of changes in average seasonal pumping rates on intraborehole flow and water quality at two long-screened, public-supply wells, in Albuquerque, New Mexico and Modesto, California, where widespread pumping has altered groundwater flow patterns. Simulation results indicate that both wells produce water requiring additional treatment to maintain potable quality in winter when groundwater withdrawals are reduced because less water is derived from parts of the aquifer that contain water requiring less treatment. Simulation results indicate that the water quality at both wells could be improved by increasing average winter-pumping rates to induce more lateral flow from parts of the aquifer that contain better quality water. Arsenic-bearing water produced by the Albuquerque well could be reduced from 55% to 45% by doubling average winter-pumping rate, while nitrate- and uranium-bearing water produced by the Modesto well could be reduced from 95% to 65% by nearly tripling the average winter-pumping rate. Higher average winter-pumping rates would also reduce the volume of intraborehole flow within both wells and prevent the exchange of poor quality water between shallow and deep parts of both aquifers.

  12. 基于多主体的舆论建模与仿真研究%Modeling and simulation of public opinion based on multi-agent system

    Institute of Scientific and Technical Information of China (English)

    刘怡君

    2011-01-01

    "Public opinion comes before the unrest" has become a consensus. Understanding and capturing the essential mechanism of opinion formation and infection will provide help for forecasting and macroeconomic regulation. Public opinion is an open complex giant system, in which studying opinion based on modeling and simulation analysis is a more comprehensive and effective means. The paper presents one overall model of methodology-method-technology-simulation from the view of systems science besides going through the definitions of Wuli-Shili-Renli and multi-agent system, then summarizes the individuals' behaviors such as "conformity","power","egoism", etc., analyzes individual choices and constructs three interaction rules. The opinion evolution process was simulated quantitatively and some primary conclusions were obtained.%“舆论在先,动乱在后”,已成为普遍共识的认知.研究舆论的形成机理及其演化规律,进而调控舆论传播的导向有着重要的理论和现实意义.舆论系统是一个典型的复杂系统,系统建模与仿真分析是舆论全方位研究的有效手段.本文以物理-事理-人理系统方法论为指导,以多主体建模方法为手段,以舆论可视化仿真平台为依托,定义了舆论主体的偏好行为,模拟了舆论演化的过程,总结了舆论演化的规律.

  13. Simulating propagation of decomposed elastic waves using low-rank approximate mixed-domain integral operators for heterogeneous transversely isotropic media

    KAUST Repository

    Cheng, Jiubing

    2014-08-05

    In elastic imaging, the extrapolated vector fields are decomposed into pure wave modes, such that the imaging condition produces interpretable images, which characterize reflectivity of different reflection types. Conventionally, wavefield decomposition in anisotropic media is costly as the operators involved is dependent on the velocity, and thus not stationary. In this abstract, we propose an efficient approach to directly extrapolate the decomposed elastic waves using lowrank approximate mixed space/wavenumber domain integral operators for heterogeneous transverse isotropic (TI) media. The low-rank approximation is, thus, applied to the pseudospectral extrapolation and decomposition at the same time. The pseudo-spectral implementation also allows for relatively large time steps in which the low-rank approximation is applied. Synthetic examples show that it can yield dispersionfree extrapolation of the decomposed quasi-P (qP) and quasi- SV (qSV) modes, which can be used for imaging, as well as the total elastic wavefields.

  14. The acoustics of public squares/places: A comparison between results from a computer simulation program and measurements in situ

    DEFF Research Database (Denmark)

    Paini, Dario; Rindel, Jens Holger; Gade, Anders

    2004-01-01

    In the contest of a PhD thesis, in which the main purpose is to analyse the importance of the public square/place (“agora”) as a meeting point of sound and music, with particular regard to its use for concerts (amplified or not), a first step was done, making comparisons between measurement in situ...... is not completely closed and not completely open, with highly reflecting and partially diffusing vertical surfaces (the facades) and with one totally absorbing surface (the sky). A natural application of these results will be the possibility to detect the best position for a sound source (typically an orchestra...... or a band during, for instance, music summer festivals) and the best position for the audience. A further result could be to propose some acoustic adjustments to achieve better acoustic quality by considering the acoustic parameters which are typically used for concert halls and opera houses....

  15. .Gov Domains API

    Data.gov (United States)

    General Services Administration — This dataset offers the list of all .gov domains, including state, local, and tribal .gov domains. It does not include .mil domains, or other federal domains outside...

  16. 多领域协同仿真的高密度永磁电机温升计算%Temperature Rise Calculations of High Density Permanent Magnet Motors Based on Multi-domain Co-simulation

    Institute of Scientific and Technical Information of China (English)

    张琪; 鲁茜睿; 黄苏融; 张俊

    2014-01-01

    为了有效解决电机温升不易准确计算的难题,该文首先提出基于多领域协同仿真的高密度永磁电机温升计算理念,详细论述温升计算的流程。基于热传导理论,论文导出槽内绕组等效导热系数的计算方法,有效地考虑了漆包线绝缘层、浸渍漆和微孔对电机温升的影响。以一台48槽/8极高密度永磁电机样机为例,基于多领域协同仿真的计算方法,精确计算样机的铁耗、计及集肤效应的交流绕组铜耗,以及永磁体的涡流损耗和电机内的温度场。最后,进行样机的温升试验,温度场计算值与试验结果基本吻合,验证了基于多领域协同仿真的高密度永磁电机温升计算方法的准确性和有效性。%In order to accurately analyze the temperature rise of high density permanent magnet motors (HDPMM), a new temperature calculation conception of the HDPMM based on multi-domain co-simulation was proposed and its calculation process was elaborated.According to the theory of heat transfer, the calculation method of equivalent heat transfer coefficient for the stator winding was deduced, which effectively consider the influence of the wire insulation, impregnating varnish and fine air gap in slots on the temperature rise of the motor. Based on multi-domain co-simulation, a prototype of 48-slot 8-pole HDPMM was simulated for its iron losses, AC winding copper losses taking the skin effect into account, permanent magnet eddy losses,and thermal fields. The temperature of the prototype machine was tested. The good agreement between the tested data and the simulated data verifies the validity and precision of the simulation approach.

  17. Isochrones as Indicators of the Influence of Traffic in Public Health: A Visual Simulation Application in Ávila, Spain

    Directory of Open Access Journals (Sweden)

    F. Javier Otamendi

    2015-10-01

    Full Text Available It is well known that excessive rescue times after traffic accidents negatively affect the health of those injured. There is a need to quantitatively measure the impact of unexpected events like ambulance availability, weather, floating population and congestion in those rescue times. A family of indicators based on isochrones is disguised and proposed to understand the risk of the whole population as the probability of not being assisted on time. Indicators of health risk for local towns are also defined. The indicators are calculated using a simulation model and visualized in web format. The framework of analysis is validated using Ávila (Spain and the problem of the optimal deployment of ambulances as a test-bench.

  18. 批判与再筑:公私二元性别规范的省思——以兰西·弗雷泽公共领域观为视角%Critique and Re -building. Reflections on the Public-Private Duality of Gender Norms--- From the Perspective of the Public Domain Concept of Lancey Fraser

    Institute of Scientific and Technical Information of China (English)

    丁慧

    2012-01-01

    公共领域和私人领域的二元划分,作为哈贝马斯的理想图景,发挥其重要的理论建构作用,在学界引起广泛影响,同时也引起了持久的争论,并且受到多方的质疑和挑战。其中,女性主义对公共领域概念进行了颠覆性的改造。女性主义对此问题的关注,主要集中在女性与社会关系、女性的社会地位等方面,以社会性别的分析视角反思单一的总括性公共领域构想,女性作为弱势群体的作用长期被忽略了。公共领域既是形成话语意见的场所,也是形成社会身份的场所。由于在历史发展过程中,女性始终处于一种无语的状态,女性的话题一直被遮蔽在权力关系之外,即使自由主义时期,家务劳动的价值没有得到确认和展开。性别偏置的问题没有得到根本性改观,基于公共领域意志所形成的性别规范和性别制度必然呈现男权主义的特征。因此,公私二元的理论修正,对于性别平等这一价值和原则而言,是重要的理论支点。%The dual division of public and private spheres, as Habermas's ideal picture, played an important role in the theoretical construction and caused widespread impacts in the academic community and a long debate, which were questioned and challenged by the parties. Among them, the concept of feminism car- ried out disruptive transformation to the concept of the public domain. Attention of feminism focuses mainly on women and social relations and women's social status. Reflecting on a single, overarching public sphere concept by gender analysis perspective we find the role of women as vulnerable groups have long been ignored. The public sphere is not only the place to form the words and views, but also the place to form the social identity. In the course of historical development women are always in a state of loss of speech, and the topic of women has been obscured in power relations~ even if in the liberal period, the val- ue of

  19. 一种多输人多输出变换域通信系统的设计与仿真%Design and simulation of a multiple-input multiple-output transform domain communication system

    Institute of Scientific and Technical Information of China (English)

    张轶; 任清华; 褚振勇

    2011-01-01

    传统的变换域通信系统TDCS(Transform Domain Communication System)在获得强抗干扰能力的同时,存在传输有效性差的问题,这已成为制约其广泛应用的技术瓶颈.通过引入多输入多输出MIMO( Multiple-input Multiple- output)技术改进收发端天线,提出了一种多输入多输出变换域通信系统( MIMO- TDCS).对其基本原理和收发信机模型作了简要介绍,并进行了信道容量的分析和仿真,结果表明,MIMO-TDCS是一种兼具传输有效性和可靠性的通信手段.%With the excellent ability of anti-interference, the conventional Transform Domain Communication System (TDCS) is conditioned in extensive application for the low data rates between the transmitter and the receiver. This paper presents a multiple-input multiple-output transform domain communication system (MIMO-TDCS) by adding MIMO and V-BLAST receiver architecture to TDCS, by which increased the channel capacity. The paper introduces the scheme and function model of MIMO-TDCS as well, and analyzes its every function module concisely. The simulative results show that MIMO-TDCS is a kind of communication technique which both has high data rates and strong anti-interference ability.

  20. Publicity and public relations

    Science.gov (United States)

    Fosha, Charles E.

    1990-01-01

    This paper addresses approaches to using publicity and public relations to meet the goals of the NASA Space Grant College. Methods universities and colleges can use to publicize space activities are presented.

  1. Research on time domain simulation of dynamic positioning for a deep water semi-submersible platform%深水半潜平台动力定位时域模拟研究

    Institute of Scientific and Technical Information of China (English)

    王磊; 孙攀; 王亮

    2011-01-01

    Based on time domain low frequency equations of horizontal motion, considering all low frequency environment loads and dynamic positioning model, a time domain simulation system of power consumption for a semi-submersible platform was established. In this paper, the law of power consumption of dynamic positioning system for a platform was researched. On the premise of meeting the positioning accuracy, the limit water depth which the dynamic positioning system can withstand was calculated, and the positioning accuracy changes with the power consumption of the dynamic positioning system for the platform was also discussed, in order to provide a guidance for engineering practice.%以低频时域水平运动方程为基础,考虑各种低频载荷作用以及动力定位模型,建立起一种半潜平台功率消耗的时域模拟系统,研究了一艘半潜平台动力定位系统功率消耗变化的规律,在满足定位精度要求的前提下计算得到了平台动力定位系统能够承受的极限水深,并对平台动力系统的定位精度随功率消耗的变化进行了探讨,以期为工程实际提供指导.

  2. Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

    Science.gov (United States)

    Clark, Brian R.; Landon, Matthew K.; Kauffman, Leon J.; Hornberger, George Z.

    2008-01-01

    Contamination of public-supply wells has resulted in public-health threats and negative economic effects for communities that must treat contaminated water or find alternative water supplies. To investigate factors controlling vulnerability of public-supply wells to anthropogenic and natural contaminants using consistent and systematic data collected in a variety of principal aquifer settings in the United States, a study of Transport of Anthropogenic and Natural Contaminants to public-supply wells was begun in 2001 as part of the U.S. Geological Survey National Water-Quality Assessment Program. The area simulated by the ground-water flow model described in this report was selected for a study of processes influencing contaminant distribution and transport along the direction of ground-water flow towards a public-supply well in southeastern York, Nebraska. Ground-water flow is simulated for a 60-year period from September 1, 1944, to August 31, 2004. Steady-state conditions are simulated prior to September 1, 1944, and represent conditions prior to use of ground water for irrigation. Irrigation, municipal, and industrial wells were simulated using the Multi-Node Well package of the modular three-dimensional ground-water flow model code, MODFLOW-2000, which allows simulation of flow and solutes through wells that are simulated in multiple nodes or layers. Ground-water flow, age, and transport of selected tracers were simulated using the Ground-Water Transport process of MODFLOW-2000. Simulated ground-water age was compared to interpreted ground-water age in six monitoring wells in the unconfined aquifer. The tracer chlorofluorocarbon-11 was simulated directly using Ground-Water Transport for comparison with concentrations measured in six monitoring wells and one public supply well screened in the upper confined aquifer. Three alternative model simulations indicate that simulation results are highly sensitive to the distribution of multilayer well bores where leakage

  3. Analysis of a simulated microarray dataset: Comparison of methods for data normalisation and detection of differential expression (Open Access publication

    Directory of Open Access Journals (Sweden)

    Mouzaki Daphné

    2007-11-01

    Full Text Available Abstract Microarrays allow researchers to measure the expression of thousands of genes in a single experiment. Before statistical comparisons can be made, the data must be assessed for quality and normalisation procedures must be applied, of which many have been proposed. Methods of comparing the normalised data are also abundant, and no clear consensus has yet been reached. The purpose of this paper was to compare those methods used by the EADGENE network on a very noisy simulated data set. With the a priori knowledge of which genes are differentially expressed, it is possible to compare the success of each approach quantitatively. Use of an intensity-dependent normalisation procedure was common, as was correction for multiple testing. Most variety in performance resulted from differing approaches to data quality and the use of different statistical tests. Very few of the methods used any kind of background correction. A number of approaches achieved a success rate of 95% or above, with relatively small numbers of false positives and negatives. Applying stringent spot selection criteria and elimination of data did not improve the false positive rate and greatly increased the false negative rate. However, most approaches performed well, and it is encouraging that widely available techniques can achieve such good results on a very noisy data set.

  4. Insights into the N-sulfation mechanism: molecular dynamics simulations of the N-sulfotransferase domain of NDST1 and mutants.

    Science.gov (United States)

    Gesteira, Tarsis F; Pol-Fachin, Laércio; Coulson-Thomas, Vivien Jane; Lima, Marcelo A; Verli, Hugo; Nader, Helena B

    2013-01-01

    Sulfation patterns along glycosaminoglycan (GAG) chains dictate their functional role. The N-deacetylase N-sulfotransferase family (NDST) catalyzes the initial downstream modification of heparan sulfate and heparin chains by removing acetyl groups from subsets of N-acetylglucosamine units and, subsequently, sulfating the residual free amino groups. These enzymes transfer the sulfuryl group from 3'-phosphoadenosine-5'-phosphosulfate (PAPS), yielding sulfated sugar chains and 3'-phosphoadenosine-5'-phosphate (PAP). For the N-sulfotransferase domain of NDST1, Lys833 has been implicated to play a role in holding the substrate glycan moiety close to the PAPS cofactor. Additionally, Lys833 together with His716 interact with the sulfonate group, stabilizing the transition state. Such a role seems to be shared by Lys614 through donation of a proton to the bridging oxygen of the cofactor, thereby acting as a catalytic acid. However, the relevance of these boundary residues at the hydrophobic cleft is still unclear. Moreover, whether Lys833, His716 and Lys614 play a role in both glycan recognition and glycan sulfation remains elusive. In this study we evaluate the contribution of NDST mutants (Lys833, His716 and Lys614) to dynamical effects during sulfate transfer using comprehensive combined docking and essential dynamics. In addition, the binding location of the glycan moiety, PAPS and PAP within the active site of NDST1 throughout the sulfate transfer were determined by intermediate state analysis. Furthermore, NDST1 mutants unveiled Lys833 as vital for both the glycan binding and subsequent N-sulfotransferase activity of NDST1.

  5. Insights into the N-sulfation mechanism: molecular dynamics simulations of the N-sulfotransferase domain of NDST1 and mutants.

    Directory of Open Access Journals (Sweden)

    Tarsis F Gesteira

    Full Text Available Sulfation patterns along glycosaminoglycan (GAG chains dictate their functional role. The N-deacetylase N-sulfotransferase family (NDST catalyzes the initial downstream modification of heparan sulfate and heparin chains by removing acetyl groups from subsets of N-acetylglucosamine units and, subsequently, sulfating the residual free amino groups. These enzymes transfer the sulfuryl group from 3'-phosphoadenosine-5'-phosphosulfate (PAPS, yielding sulfated sugar chains and 3'-phosphoadenosine-5'-phosphate (PAP. For the N-sulfotransferase domain of NDST1, Lys833 has been implicated to play a role in holding the substrate glycan moiety close to the PAPS cofactor. Additionally, Lys833 together with His716 interact with the sulfonate group, stabilizing the transition state. Such a role seems to be shared by Lys614 through donation of a proton to the bridging oxygen of the cofactor, thereby acting as a catalytic acid. However, the relevance of these boundary residues at the hydrophobic cleft is still unclear. Moreover, whether Lys833, His716 and Lys614 play a role in both glycan recognition and glycan sulfation remains elusive. In this study we evaluate the contribution of NDST mutants (Lys833, His716 and Lys614 to dynamical effects during sulfate transfer using comprehensive combined docking and essential dynamics. In addition, the binding location of the glycan moiety, PAPS and PAP within the active site of NDST1 throughout the sulfate transfer were determined by intermediate state analysis. Furthermore, NDST1 mutants unveiled Lys833 as vital for both the glycan binding and subsequent N-sulfotransferase activity of NDST1.

  6. Overlap/Domain-wall reweighting

    CERN Document Server

    Fukaya, H; Cossu, G; Hashimoto, S; Kaneko, T; Noaki, J

    2013-01-01

    We investigate the eigenvalues of nearly chiral lattice Dirac operators constructed with five-dimensional implementations. Allowing small violation of the Ginsparg-Wilson relation, the HMC simulation is made much faster while the eigenvalues are not significantly affected. We discuss the possibility of reweighting the gauge configurations generated with domain-wall fermions to those of exactly chiral lattice fermions.

  7. The role of public policies in reducing smoking prevalence in California: results from the California tobacco policy simulation model.

    Science.gov (United States)

    Levy, David T; Hyland, Andrew; Higbee, Cheryl; Remer, Lillian; Compton, Christine

    2007-07-01

    Tobacco control policies are examined utilizing a simulation model for California, the state with the longest running comprehensive program. We assess the impact of the California Tobacco Control Program (CTCP) and surrounding price changes on smoking prevalence and smoking-attributable deaths. Modeling begins in 1988 and progresses chronologically to 2004, and considers four types of policies (taxes, mass media, clean air laws, and youth access policies) independently and as a package. The model is validated against existing smoking prevalence estimates. The difference in trends between predicted smoking rates from the model and other commonly used estimates of smoking prevalence for the overall period were generally small. The model also predicted some important changes in trend, which occurred with changes in policy. The California SimSmoke model estimates that tobacco control policies reduced smoking rates in California by an additional 25% relative to the level that they would have been if policies were kept at their 1988 level. By 2004, the model attributes 59% of the reduction to price increases, 28% of the overall effect to media policies, 11% to clean air laws, and only a small percent to youth access policies. The model estimates that over 5000 lives will be saved in the year 2010 alone as a result of the CTCP and industry-initiated price increases, and that over 50,000 lives were saved over the period 1988-2010. Tobacco control policies implemented as comprehensive tobacco control strategies have significantly impacted smoking rates. Further tax increases should lead to additional lives saved, and additional policies may result in further impacts on smoking rates, and consequently on smoking-attributable health outcomes in the population.

  8. The role of public policies in reducing smoking prevalence: results from the Michigan SimSmoke tobacco policy simulation model.

    Science.gov (United States)

    Levy, David T; Huang, An-Tsun; Havumaki, Joshua S; Meza, Rafael

    2016-05-01

    Michigan has implemented several of the tobacco control policies recommended by the World Health Organization MPOWER goals. We consider the effect of those policies and additional policies consistent with MPOWER goals on smoking prevalence and smoking-attributable deaths (SADs). The SimSmoke tobacco control policy simulation model is used to examine the effect of past policies and a set of additional policies to meet the MPOWER goals. The model is adapted to Michigan using state population, smoking, and policy data starting in 1993. SADs are estimated using standard attribution methods. Upon validating the model, SimSmoke is used to distinguish the effect of policies implemented since 1993 against a counterfactual with policies kept at their 1993 levels. The model is then used to project the effect of implementing stronger policies beginning in 2014. SimSmoke predicts smoking prevalence accurately between 1993 and 2010. Since 1993, a relative reduction in smoking rates of 22 % by 2013 and of 30 % by 2054 can be attributed to tobacco control policies. Of the 22 % reduction, 44 % is due to taxes, 28 % to smoke-free air laws, 26 % to cessation treatment policies, and 2 % to youth access. Moreover, 234,000 SADs are projected to be averted by 2054. With additional policies consistent with MPOWER goals, the model projects that, by 2054, smoking prevalence can be further reduced by 17 % with 80,000 deaths averted relative to the absence of those policies. Michigan SimSmoke shows that tobacco control policies, including cigarette taxes, smoke-free air laws, and cessation treatment policies, have substantially reduced smoking and SADs. Higher taxes, strong mass media campaigns, and cessation treatment policies would further reduce smoking prevalence and SADs.

  9. Determining Favorable Binding Configurations of the Anti-Cancer Drug Ellipticine to the KV11.1 Potassium Channel V-VI Transmembrane Domain Through Autodock Simulations

    Science.gov (United States)

    Lipscomb, Dawn; Gentile, Saverio; Brancaleon, Lorenzo

    2011-10-01

    Ellipticines such as 9-methoxy-N-2-methylellipticinium acetate (MMEA) and 9-hydroxy-N-2-methylellipticinium acetate (NMEA, Celiptium ) are antineoplastic drugs that exert their selective cytotoxicity against leukemia and endometrial carcinoma. Ellipticine's action is also related to severe physical side effects, but the link between undesired effects and pharmacological application is not well understood. We investigated the binding of Ellipticine derivatives with the Kv11.1 potassium ion channel using Autodock and revealed that hydroxyellipticinium derivatives provide binding configurations with Kv11.1, but the energy, location and estimated dissociation constant varied. The binding energy is as follows: Chloroceliptium (-6.60 kcal/mol) > Celiptium (- 6.37 kcal/mol) > Methoxyceliptium (- 6.20 kcal/mol) > Datelliptium (-6.08 kcal/mol). Autodock simulations demonstrate that binding affinity is high at opposing ends of the channel and low within the channel interior. These favorable binding configurations suggest that Ellipticine derivatives may bridge among end subunits of the channel and potentially inhibit the flow of ions.

  10. Ubiquitin domain proteins in disease

    DEFF Research Database (Denmark)

    Klausen, Louise Kjær; Schulze, Andrea; Seeger, Michael

    2007-01-01

    The human genome encodes several ubiquitin-like (UBL) domain proteins (UDPs). Members of this protein family are involved in a variety of cellular functions and many are connected to the ubiquitin proteasome system, an essential pathway for protein degradation in eukaryotic cells. Despite their s...... and cancer. Publication history: Republished from Current BioData's Targeted Proteins database (TPdb; http://www.targetedproteinsdb.com).......The human genome encodes several ubiquitin-like (UBL) domain proteins (UDPs). Members of this protein family are involved in a variety of cellular functions and many are connected to the ubiquitin proteasome system, an essential pathway for protein degradation in eukaryotic cells. Despite...

  11. Modelling the interplate domain in thermo-mechanical simulations of subduction: Critical effects of resolution and rheology, and consequences on wet mantle melting

    Science.gov (United States)

    Arcay, Diane

    2017-08-01

    The present study aims at better deciphering the different mechanisms involved in the functioning of the subduction interplate. A 2D thermo-mechanical model is used to simulate a subduction channel, made of oceanic crust, free to evolve. Convergence at constant rate is imposed under a 100 km thick upper plate. Pseudo-brittle and non-Newtonian behaviours are modelled. The influence of the subduction channel strength, parameterized by the difference in activation energy between crust and mantle (ΔEa) is investigated to examine in detail the variations in depth of the subduction plane down-dip extent, zcoup . First, simulations show that numerical resolution may be responsible for an artificial and significant shallowing of zcoup if the weak crustal layer is not correctly resolved. Second, if the age of the subducting plate is 100 Myr, subduction occurs for any ΔEa . The stiffer the crust is, that is, the lower ΔEa is, the shallower zcoup is (60 km depth if ΔEa = 20 kJ/mol) and the hotter the fore-arc base is. Conversely, imposing a very weak subduction channel (ΔEa > 135 J/mol) leads there to an extreme mantle wedge cooling and inhibits mantle melting in wet conditions. Partial kinematic coupling at the fore-arc base occurs if ΔEa = 145 kJ/mol. If the incoming plate is 20 Myr old, subduction can occur under the conditions that the crust is either stiff and denser than the mantle, or weak and buoyant. In the latter condition, cold crust plumes rise from the subduction channel and ascend through the upper lithosphere, triggering (1) partial kinematic coupling under the fore-arc, (2) fore-arc lithosphere cooling, and (3) partial or complete hindrance of wet mantle melting. zcoup then ranges from 50 to more than 250 km depth and is time-dependent if crust plumes form. Finally, subduction plane dynamics is intimately linked to the regime of subduction-induced corner flow. Two different intervals of ΔEa are underlined: 80-120 kJ/mol to reproduce the range of slab

  12. Self-consistent simulations of a von Kármán type dynamo in a spherical domain with metallic walls.

    Science.gov (United States)

    Guervilly, Céline; Brummell, Nicholas H

    2012-10-01

    We have performed numerical simulations of boundary-driven dynamos using a three-dimensional nonlinear magnetohydrodynamical model in a spherical shell geometry. A conducting fluid of magnetic Prandtl number Pm=0.01 is driven into motion by the counter-rotation of the two hemispheric walls. The resulting flow is of von Kármán type, consisting of a layer of zonal velocity close to the outer wall and a secondary meridional circulation. Above a certain forcing threshold, the mean flow is unstable to non-axisymmetric motions within an equatorial belt. For fixed forcing above this threshold, we have studied the dynamo properties of this flow. The presence of a conducting outer wall is essential to the existence of a dynamo at these parameters. We have therefore studied the effect of changing the material parameters of the wall (magnetic permeability, electrical conductivity, and thickness) on the dynamo. In common with previous studies, we find that dynamos are obtained only when either the conductivity or the permeability is sufficiently large. However, we find that the effect of these two parameters on the dynamo process are different and can even compete to the detriment of the dynamo. Our self-consistent approach allow us to analyze in detail the dynamo feedback loop. The dynamos we obtain are typically dominated by an axisymmetric toroidal magnetic field and an axial dipole component. We show that the ability of the outer shear layer to produce a strong toroidal field depends critically on the presence of a conducting outer wall, which shields the fluid from the vacuum outside. The generation of the axisymmetric poloidal field, on the other hand, occurs in the equatorial belt and does not depend on the wall properties.

  13. 基于Modelica太阳能电动汽车多领域统一建模与仿真%The Solar Electric Vehicle Multi-Domain Modeling and Simulation Based on Modelica

    Institute of Scientific and Technical Information of China (English)

    熊会元; 陈承鹤; 宗志坚; 于丽敏

    2011-01-01

    基于多领域建模语言Modelica与太阳能电动车物理结构,建立了面向对象、层次化和模块化的整车仿真模型,基于模型库,建立电池、电机及驱动、底盘及控制等子系统多领域统一模型,结合试验对关键部件模型进行验证及参数标定,实现了各系统模型无缝连接.在试验行驶工况下,完成整车的动力性与能耗经济性仿真,仿真与试验结果较为吻合,验证了方法的正确性,为电动汽车提供全新开发方法.%The object-oriented, hierarchical and modular solar vehicle simulation model was established, Based on the Multi-domain modeling language Modelica and the solar EV structure. With the modelica model library, battery, motor drive system,chassis and control sub-system model were modeled . According to the test of the key components; the model parameters were validation and calibration to achieve a seamless model connection. Using the driving cycle test, vehicle dynamics and energy economy simulation were completed, and the simulation and experimental results are more consistent, that verify the correctness of the modeling method, which provide a new method for electric vehicles.

  14. 基于时域仿真法的大扰动下船舶电站暂态稳定分析%Transient stability analysis of ship power station under large disturbance based on time domain simulation

    Institute of Scientific and Technical Information of China (English)

    谢心怡; 刘彦呈

    2011-01-01

    针对目前普遍采用的低阶同步发电机数学模型在大扰动下船舶电站暂态稳定分析中计算误差大的缺陷,以及MATLAB算法受限且仿真时间过长的不足,应用时域仿真法,综合同步发电机、柴油机及其调速系统、励磁系统以及负荷数学模型建立船舶电站高阶非线性模型,并用隐式梯形积分法的C#.NET程序求解非线性微分代数方程组.比较大扰动前后发电机转速和端电压动态仿真曲线,其各项性能指标均在规范误差范围内.%Aiming at the disadvantages of big calculative error of low-order synchronous generator model currently widely used in transient stability analysis under large disturbance,limited MATLAB method and too long simulation time,the high-order nonlinear model of ship power station was established combining nonlinear mathematical models of generator,diesel engine and governor system,as well as excitation system and load using time domain simulation.The implicit trapezoidal integration method was selected to solve nonlinear differential algebraic equations with C#.NET program instead of time-consuming MATLAB.The simulation curves of rotor speed and voltage disturbance pre and post were compared,and results show that each performance index is within standard error range.

  15. Magnetic domain structure in thin CoPt perpendicular magnetic anisotropy films

    Directory of Open Access Journals (Sweden)

    Komine T.

    2013-01-01

    Full Text Available The relation between thickness and domain structure of Co80Pt20 perpendicular magnetic anisotropy films was investigated through experiments and micromagnetic simulation. The films with thickness over 10 nm exhibited clear maze domain structure, while for the films thinner than 10 nm the domain structure abruptly changed from maze domain to irregular and large domain as the thickness became thinner. The irregular domain had narrower domain wall width than maze domain.

  16. Simulation Exercises

    Science.gov (United States)

    Tansey, Pat

    1976-01-01

    Describes five simulation exercises: a problem for a student teacher, an industrial relations game, a series of student problems; an international relations crisis, and a sociological exercise on public and private opinions. (LS)

  17. Sequential simulation (SqS) of clinical pathways: a tool for public and patient engagement in point-of-care diagnostics.

    Science.gov (United States)

    Huddy, Jeremy R; Weldon, Sharon-Marie; Ralhan, Shvaita; Painter, Tim; Hanna, George B; Kneebone, Roger; Bello, Fernando

    2016-09-13

    Public and patient engagement (PPE) is fundamental to healthcare research. To facilitate effective engagement in novel point-of-care tests (POCTs), the test and downstream consequences of the result need to be considered. Sequential simulation (SqS) is a tool to represent patient journeys and the effects of intervention at each and subsequent stages. This case study presents a process evaluation of SqS as a tool for PPE in the development of a volatile organic compound-based breath test POCT for the diagnosis of oesophagogastric (OG) cancer. Three 3-hour workshops in central London. 38 members of public attended a workshop, 26 (68%) had no prior experience of the OG cancer diagnostic pathway. Clinical pathway SqS was developed from a storyboard of a patient, played by an actor, noticing symptoms of oesophageal cancer and following a typical diagnostic pathway. The proposed breath testing strategy was then introduced and incorporated into a second SqS to demonstrate pathway impact. Facilitated group discussions followed each SqS. Evaluation was conducted through pre-event and postevent questionnaires, field notes and analysis of audiovisual recordings. 38 participants attended a workshop. All participants agreed they were able to contribute to discussions and like the idea of an OG cancer breath test. Five themes emerged related to the proposed new breath test including awareness of OG cancer, barriers to testing and diagnosis, design of new test device, new clinical pathway and placement of test device. 3 themes emerged related to the use of SqS: participatory engagement, simulation and empathetic engagement, and why participants attended. SqS facilitated a shared immersive experience for participants and researchers that led to the coconstruction of knowledge that will guide future research activities and be of value to stakeholders concerned with the invention and adoption of POCT. Published by the BMJ Publishing Group Limited. For permission to use (where not

  18. A typology of public engagement mechanisms

    NARCIS (Netherlands)

    Rowe, G.; Frewer, L.J.

    2005-01-01

    Imprecise definition of key terms in the "public participation" domain have hindered the conduct of good research and militated against the development and implementation of effective participation practices. In this article, we define key concepts in the domain: public communication, public consult

  19. Public Education, Public Good.

    Science.gov (United States)

    Tomlinson, John

    1986-01-01

    Criticizes policies which would damage or destroy a public education system. Examines the relationship between government-provided education and democracy. Concludes that privatization of public education would emphasize self-interest and selfishness, further jeopardizing the altruism and civic mindedness necessary for the public good. (JDH)

  20. Time-domain nature of group delay

    Institute of Scientific and Technical Information of China (English)

    王建武; 冯正和

    2015-01-01

    The characteristic of group delay is analyzed based on an electronic circuit, and its time-domain nature is studied with time-domain simulation and experiment. The time-domain simulations and experimental results show that group delay is the delay of the energy center of the amplitude-modulated pulse, rather than the propagation delay of the electromagnetic field. As group velocity originates from the definition of group delay and group delay is different from the propagation delay, the superluminality or negativity of group velocity does not mean the superluminal or negative propagation of the electromagnetic field.

  1. Interaction Design for Public Spaces

    DEFF Research Database (Denmark)

    Kortbek, Karen Johanne

    2008-01-01

    In this abstract I describe the doctorial research project "Interaction Design for Public Spaces". The objective of the project is to explore and design interaction contexts in culture related public spaces such as museums, experience centres and festivals. As a perspective on this domain, I...... will help interaction designers when designing for bodily movement, and communicating and staging interactive content in public spaces....

  2. Definition and identification of homology domains.

    Science.gov (United States)

    Lawrence, C B; Goldman, D A

    1988-03-01

    A method is described for identifying and evaluating regions of significant similarity between two sequences. The notion of a 'homology domain' is employed which defines the boundaries of a region of sequence homology containing no insertions or deletions. The relative significance of different potential homology domains is evaluated using a non-linear similarity score related to the probability of finding the observed level of similarity in the region by chance. The sensitivity of the method is demonstrated by simulating the evolution of homology domains and applying the method to their detection. Several examples of the use of homology domain identification are given.

  3. 盘式制动器NVH性能的时-频域耦合仿真方法%Coupling Simulation Method for Disc Brake NVH Performance Evaluation in Time-frequency Domain

    Institute of Scientific and Technical Information of China (English)

    彭涛; 周亨; 田振勇

    2016-01-01

    汽车制动时的NVH性能对于乘车舒适性和防治环境噪声污染具有重要意义。目前常规的仿真方法为复特征值(CEA)法,通常CEA法比实际测试出现的制动尖叫频率点更多,容易造成误判。为此,提出采用时-频域耦合动态仿真方法对盘式制动器的NVH性能进行分析。基于有限元平台ABAQUS,根据国际噪声测试标准SAE J 2521规定的工况,分别采用CEA法和时-频域耦合仿真方法,对制动器的非稳态响应进行了分析,得到了制动器的加速度-频率响应曲线以及制动尖叫的频率点;将时-频域耦合仿真及CEA仿真结果与测试结果进行比较,结果表明:传统的CEA仿真得到的的尖叫频率值过多,相比之下时-频域耦合仿真得到的结果与测试数据更为吻合,能够更精准地预测制动器的尖叫噪声频率值。%During car braking, NVH performance is of great significance for ride comfort and environmental noise prevention. Currently, the conventional simulation method is the complex eigenvalue analysis (CEA) method. But this method usually gets more squeal frequencies than the test results which may cause misjudgments. So, the coupling dynamic simulation method in the time-frequency domain was brought up to analyze the NVH performance of disc brakes. Based on the finite element platform of ABAQUS, and according to the international noise test standard SAE J2521, both the CEA method and the implicit-explicit coupling simulation method were adopted to analyze the unsteady response of a disc brake. And the acceleration-frequency response curve of the brake and the frequency sampling points of the braking squeal were obtained. Both results from implicit-explicit coupling simulation and CEA method were compared with the test results. Results show that the CEA can get more squeal frequencies than the test results, but the results from time-frequency domain coupling method are in good agreement with the

  4. Survivability-enhancing routing scheme for multi-domain networks

    DEFF Research Database (Denmark)

    Li, Xiaohua; Ruepp, Sarah Renée; Manolova, Anna Vasileva

    2008-01-01

    domain level disjoint paths. Our work is based on the aggregated representation of transit domains. The aggregated scheme we use is obtaining the shortest path between each pair of border routers for the associated domain. We also propose to use a single node to represent the destination domain, thereby......, while intra-domain link failures can be repaired by neighboring nodes, border routers or at domain level. The intra-domain repair methods are compared by simulation and based on the results border router repairing is recommended....

  5. Time Domain Stability Margin Assessment Method

    Science.gov (United States)

    Clements, Keith

    2017-01-01

    The baseline stability margins for NASA's Space Launch System (SLS) launch vehicle were generated via the classical approach of linearizing the system equations of motion and determining the gain and phase margins from the resulting frequency domain model. To improve the fidelity of the classical methods, the linear frequency domain approach can be extended by replacing static, memoryless nonlinearities with describing functions. This technique, however, does not address the time varying nature of the dynamics of a launch vehicle in flight. An alternative technique for the evaluation of the stability of the nonlinear launch vehicle dynamics along its trajectory is to incrementally adjust the gain and/or time delay in the time domain simulation until the system exhibits unstable behavior. This technique has the added benefit of providing a direct comparison between the time domain and frequency domain tools in support of simulation validation.

  6. 环形狭缝腔阵列光学特性的研究∗%Finite difference time domain simulation of optical prop erties of annular cavity arrays

    Institute of Scientific and Technical Information of China (English)

    周静; 王鸣; 倪海彬; 马鑫

    2015-01-01

    Optical properties of two-dimensional periodic annular cavity arrays in hexagonal packing are investigated by finite difference time domain simulation method in this paper. According to simulated reflectance/transmission spectra, electric field distribution and charge distribution, we confirm that multiple cylindrical surface plasmon resonances, which result in reflectance dips, can be excited in annular cavities by linearly polarized light. Mechanism of the cylindrical surface plasmons is investigated. A coaxial waveguide mode TE11 is excited in the annular cavities and a Fabry-Perot resonance is fulfilled along the depth direction of the annular cavities at the resonance wavelengths. While the number of reflectance dips and wavelengths of these dips in reflectance spectra are dependent on the geometric sizes of the annular cavities, the periodicity and polarization of incident light do not affect their reflectance spectra dramatically. Incident light beams with resonant wavelengths are localized in annular cavities with large electric field increasing and dissipate gradually due to metal loss. Reflectance dips can be tuned from 350 to 2000 nm by adjusting geometric size parameters of the annular cavities, such as outer and inner radii of the annular gaps, gap sizes and metal film thickness values. Reflectance dips shift toward longer wavelength with increasing inner and outer radii of the annular gaps, metal film thickness and with reducing the gap distance. In addition, infiltrate liquids in the annular gaps will result in a shift of the resonance wavelengths, which makes the annular cavities good refractive index sensors. A refractive index sensitivity up to 1850 nm/RIU is demonstrated. The refractive index sensitivities of annular cavities can also be tuned by their geometric sizes. Annular cavities with large electric field enhancement and tunable cylindrical surface plasmons can be used as surface enhanced Raman spectra substrates, refractive index sensors

  7. 基于MATLAB的连续时间LTI系统的时域分析与仿真设计%Time Domain Analysis and Simulation Design of Continuous Time LTI System Based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    原立格; 郝洋洲; 崔羊威

    2015-01-01

    The study of signal and system has a high demand for mathematics skills,so the students in the process of learning feel a certain degree of difficulty,and then they will reduce the interest in learning. In this paper,MATLAB software with the powerful function of numerical calculation and programming simulation has been combined with the course of signal and system, time domain analysis and simulation of the continuous time LTI system was studied by using MATLAB software,and the GUI interface has been effectively used to combine signal and system course and MATLAB curriculum,so as to improve the students' interest in learning and cultivate their good habits of learning with the integration of different courses.%《信号与系统》课程的学习对数学功底要求较高,因此学习起来有一定难度,进而会减少学生学习兴趣。本文将具有数值计算、编程仿真等强大功能的MATLAB软件与《信号与系统》课程相结合,利用MATLAB软件研究连续时间LTI系统的时域分析与仿真,并利用GUI界面有效地将《信号与系统》课程和MATLAB课程相结合,从而提高学生学习兴趣并培养学生将不同课程融合学习的好习惯。

  8. Radiative transfer with scattering for domain-decomposed 3D MHD simulations of cool stellar atmospheres. Numerical methods and application to the quiet, non-magnetic, surface of a solar-type star

    Science.gov (United States)

    Hayek, W.; Asplund, M.; Carlsson, M.; Trampedach, R.; Collet, R.; Gudiksen, B. V.; Hansteen, V. H.; Leenaarts, J.

    2010-07-01

    Aims: We present the implementation of a radiative transfer solver with coherent scattering in the new BIFROST code for radiative magneto-hydrodynamical (MHD) simulations of stellar surface convection. The code is fully parallelized using MPI domain decomposition, which allows for large grid sizes and improved resolution of hydrodynamical structures. We apply the code to simulate the surface granulation in a solar-type star, ignoring magnetic fields, and investigate the importance of coherent scattering for the atmospheric structure. Methods: A scattering term is added to the radiative transfer equation, requiring an iterative computation of the radiation field. We use a short-characteristics-based Gauss-Seidel acceleration scheme to compute radiative flux divergences for the energy equation. The effects of coherent scattering are tested by comparing the temperature stratification of three 3D time-dependent hydrodynamical atmosphere models of a solar-type star: without scattering, with continuum scattering only, and with both continuum and line scattering. Results: We show that continuum scattering does not have a significant impact on the photospheric temperature structure for a star like the Sun. Including scattering in line-blanketing, however, leads to a decrease of temperatures by about 350 K below log10 τ5000 ⪉ -4. The effect is opposite to that of 1D hydrostatic models in radiative equilibrium, where scattering reduces the cooling effect of strong LTE lines in the higher layers of the photosphere. Coherent line scattering also changes the temperature distribution in the high atmosphere, where we observe stronger fluctuations compared to a treatment of lines as true absorbers.

  9. 基于详细时域仿真的ASVG静态与动态特性分析%ANALYSIS OF THE STATIC AND DYNAMIC CHARACTERISTICS OF ASVG BASED ON DETAILED TIME DOMAIN SIMULATION

    Institute of Scientific and Technical Information of China (English)

    李必涛; 朱一锋; 程时杰

    2001-01-01

    Based on SIMULINK, a simulation tool of MATLAB, a detailed time domain model of the advanced static VAR generator (ASVG) with capacitor as its energy storage device is developed in this paper. The steady state and dynamic characteristics of ASVG are analyzed with the help of this model. The research is mainly focused on the following aspects: ① The relationship between the trigging angle of GTO, the trigging pulse width and the angular difference between the output voltage of the ASVG and the voltage at the point where the ASVG was connected; ② The main factors which affect the active and reactive power outputs of this type of ASVG. At last, a mathematical model representing the transient characteristics of the ASVG is obtained from the simulation results under different disturbance.%基于MATLAB中的SIMULINK仿真工具,建立了电容型静止补偿器(ASVG)的仿真模型,并对其静态特性和动态特性进行了全时域仿真分析。通过对仿真结果的分析,得出了ASVG的输出电压与它和系统接入点电压间的相角差、ASVG晶闸管触发脉冲、触发脉宽之间的关系,这为ASVG的触发脉冲和触发脉宽的设计提供了依据。同时,文中还对影响电容型ASVG静态输出(或吸收)的有功功率和无功功率的因素进行了详细的分析。最后,通过对ASVG受扰后暂态响应曲线的分析,提出了一种ASVG的动态响应模型。

  10. Protein domain prediction

    NARCIS (Netherlands)

    Ingolfsson, Helgi; Yona, Golan

    2008-01-01

    Domains are considered to be the building blocks of protein structures. A protein can contain a single domain or multiple domains, each one typically associated with a specific function. The combination of domains determines the function of the protein, its subcellular localization and the interacti

  11. The Sonar Simulation Toolset, Release 4.1: Science, Mathematics and Algorithms

    Science.gov (United States)

    2005-03-01

    like Mathematica [Mathematica] or Matlab [Mat- lab], or public-domain tools like Octave [Octave] or Gnuplot [ Gnuplot ], specialized tools like the SIO... Gnuplot ] T. Williams and C. Kelley, gnuplot , http://www.gnuplot.info/. 2.2 [Goddard 1986] R. P. Goddard, “REVGEN-4 High-Fidelity Simulation of Sonar

  12. Prediction of Solution Properties of Flexible-Chain Polymers: A Computer Simulation Undergraduate Experiment

    Science.gov (United States)

    de la Torre, Jose Garcia; Cifre, Jose G. Hernandez; Martinez, M. Carmen Lopez

    2008-01-01

    This paper describes a computational exercise at undergraduate level that demonstrates the employment of Monte Carlo simulation to study the conformational statistics of flexible polymer chains, and to predict solution properties. Three simple chain models, including excluded volume interactions, have been implemented in a public-domain computer…

  13. Membrane binding domains

    OpenAIRE

    Hurley, James H.

    2006-01-01

    Eukaryotic signaling and trafficking proteins are rich in modular domains that bind cell membranes. These binding events are tightly regulated in space and time. The structural, biochemical, and biophysical mechanisms for targeting have been worked out for many families of membrane binding domains. This review takes a comparative view of seven major classes of membrane binding domains, the C1, C2, PH, FYVE, PX, ENTH, and BAR domains. These domains use a combination of specific headgroup inter...

  14. Electric-field-driven dynamics of magnetic domain walls in magnetic nanowires patterned on ferroelectric domains

    OpenAIRE

    Van de Wiele, Ben; Leliaert, Jonathan; Franke, Kévin; van Dijken, Sebastiaan

    2016-01-01

    Strong coupling of magnetic domain walls onto straight ferroelastic boundaries of a ferroelectric layer enables full and reversible electric-field control of magnetic domain wall motion. In this paper, the dynamics of this new driving mechanism is analyzed using micromagnetic simulations. We show that transverse domain walls with a near-180° spin structure are stabilized in magnetic nanowires and that electric fields can move these walls with high velocities. Above a critical velocity, which ...

  15. Predictive Modeling & Simulation for Propagation of Internet Public Opinion%因特网上舆情传播的预测建模和仿真研究

    Institute of Scientific and Technical Information of China (English)

    方薇; 何留进; 宋良图

    2012-01-01

    The Internet Public Opinion(IPO) usually expresses the voice of masses,although it hdue to the common attribute of the society opinion,but due to the large scope of influence and fast propagation on Internet,it has been attracted much attention to its tendency of propagation. The paper firstly studied the computer model and its algorithm to predict the propagation of IPO,I. E. The distributed probability of positive or negative opinion. Then the simulation gave the propagation order for growing or descending. In order to modeling, the propagation of IPO was observed as a random Markov time sequence chain,and its one step transition probability between states in the Markov chain was given by a synergistic probability which developeds Dr. H. Haken in his book of synergistic theory. A Synergistic-Markov model was proposed in the paper. By the simulation, the cluster of curves which expresses different evolving states of IPO propagation with time was depicted when we changed the variable parameters at the formula of synergistic probability. The result could provide reference for the management of virtual society.%网络舆情一定程度上表达出社会公众意愿,它虽然具有一般社会的舆论共性,但由于因特网的影响范围及传播速度,使其在虚拟社会中具有复杂系统的基本特征,故其传播倾向及发展方向受到重视.首先研究整体情感(正、负面)传播的预测模型及其算法;然后通过仿真找出影响其增长和消亡的规律.建模的出发点是将舆情传播看作一个时间序列的马尔科夫链;再利用哈肯协同理论提供的协同概率作为马尔科夫链的状态一步转移概率,构成一个协同-马尔科夫模型.在仿真实验中改变协同概率的各个参变量,以获取舆情随时间传播的不同演化过程的曲线簇,其结果可为虚拟社会管理提供参考.

  16. Public Speech.

    Science.gov (United States)

    Green, Thomas F.

    1994-01-01

    Discusses the importance of public speech in society, noting the power of public speech to create a world and a public. The paper offers a theory of public speech, identifies types of public speech, and types of public speech fallacies. Two ways of speaking of the public and of public life are distinguished. (SM)

  17. Domains via Graphs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guoqiang; CHEN Yixiang

    2001-01-01

    This paper provides a concrete and simple introduction to two pillars of domain theory: (1) solving recursive domain equations, and (2) universal and saturated domains. Our exposition combines Larsen and Winskel's idea on solving domain equations using information systems with Girard's idea of stable domain theory in the form of coherence spaces, or graphs.Detailed constructions are given for universal and even homogeneous objects in two categories of graphs: one representing binary complete, prime algebraic domains with complete primes covering the bottom; the other representing ω-algebraic, prime algebraic lattices. The backand-forth argument in model theory helps to enlighten the constructions.

  18. Public Engagement Through Shared Immersion: Participating in the Processes of Research.

    Science.gov (United States)

    Tang, Jessica Janice; Maroothynaden, Jason; Bello, Fernando; Kneebone, Roger

    2013-10-01

    Recently, the literature has emphasized the aims and logistics of public engagement, rather than its epistemic and cultural processes. In this conceptual article, we use our work on surgical simulation to describe a process that has moved from the classroom and the research laboratory into the public sphere. We propose an innovative shared immersion model for framing the relationship between engagement activities and research. Our model thus frames the public engagement experience as a participative encounter, which brings visitor and researcher together in a shared (surgical) experience mediated by experts from a range of domains.

  19. Replacement of annular domain with trapezoidal domain in computational modeling of nonaqueous-phase-liquid dissolution-front propagation problems

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chong-bin; Thomas POULET; Klaus REGENAUER-LIEB

    2015-01-01

    In order to simulate the instability phenomenon of a nonaqueous phase liquid (NAPL) dissolution front in a computational model, the intrinsic characteristic length is commonly used to determine the length scale at which the instability of the NAPL dissolution front can be initiated. This will require a huge number of finite elements if a whole NAPL dissolution system is simulated in the computational model. Even though modern supercomputers might be used to tackle this kind of NAPL dissolution problem, it can become prohibitive for commonly-used personal computers to do so. The main purpose of this work is to investigate whether or not the whole NAPL dissolution system of an annular domain can be replaced by a trapezoidal domain, so as to greatly reduce the requirements for computer efforts. The related simulation results have demonstrated that when the NAPL dissolution system under consideration is in a subcritical state, if the dissolution pattern around the entrance of an annulus domain is of interest, then a trapezoidal domain cannot be used to replace an annular domain in the computational simulation of the NAPL dissolution system. However, if the dissolution pattern away from the vicinity of the entrance of an annulus domain is of interest, then a trapezoidal domain can be used to replace an annular domain in the computational simulation of the NAPL dissolution system. When the NAPL dissolution system under consideration is in a supercritical state, a trapezoidal domain cannot be used to replace an annular domain in the computational simulation of the NAPL dissolution system.

  20. Domains of laminin

    DEFF Research Database (Denmark)

    Engvall, E; Wewer, U M

    1996-01-01

    Extracellular matrix molecules are often very large and made up of several independent domains, frequently with autonomous activities. Laminin is no exception. A number of globular and rod-like domains can be identified in laminin and its isoforms by sequence analysis as well as by electron...... microscopy. Here we present the structure-function relations in laminins by examination of their individual domains. This approach to viewing laminin is based on recent results from several laboratories. First, some mutations in laminin genes that cause disease have affected single laminin domains, and some...... laminin isoforms lack particular domains. These mutants and isoforms are informative with regard to the activities of the mutated and missing domains. These mutants and isoforms are informative with regard to the activities of the mutated and missing domains. Second, laminin-like domains have now been...

  1. Velo: A Knowledge Management Framework for Modeling and Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, Ian; Sivaramakrishnan, Chandrika; Black, Gary D.; White, Signe K.; Purohit, Sumit; Lansing, Carina S.; Madison, Michael C.; Schuchardt, Karen L.; Liu, Yan

    2012-03-01

    Modern scientific enterprises are inherently knowledge-intensive. Scientific studies in domains such as geosciences, climate, and biology require the acquisition and manipulation of large amounts of experimental and field data to create inputs for large-scale computational simulations. The results of these simulations are then analyzed, leading to refinements of inputs and models and additional simulations. The results of this process must be managed and archived to provide justifications for regulatory decisions and publications that are based on the models. In this paper we introduce our Velo framework that is designed as a reusable, domain independent knowledge management infrastructure for modeling and simulation. Velo leverages, integrates and extends open source collaborative and content management technologies to create a scalable and flexible core platform that can be tailored to specific scientific domains. We describe the architecture of Velo for managing and associating the various types of data that are used and created in modeling and simulation projects, as well as the framework for integrating domain-specific tools. To demonstrate realizations of Velo, we describe examples from two deployed sites for carbon sequestration and climate modeling. These provide concrete example of the inherent extensibility and utility of our approach.

  2. Velo: Riding the Knowledge Management Wave for Simulation and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, Ian; Sivaramakrishnan, Chandrika; Black, Gary D.; White, Signe K.; Purohit, Sumit; Madison, Michael C.; Schuchardt, Karen L.

    2011-05-28

    Modern scientific enterprises are inherently knowledge-intensive. In general, scientific studies in domains such as geosciences, climate, and biology require the acquisition and manipulation of large amounts of experimental and field data in order to create inputs for large-scale computational simulations. The results of these simulations must then be analyzed, leading to refinements of inputs and models and further simulations. Further, these results must be managed and archived to provide justifications for publications and regulatory decisions that are based on these models. In this paper we describe our Velo framework that is designed as a reusable, domain independent knowledge management infrastructure for modeling and simulation. Velo leverages, integrates, and extends open source collaborative and content management technologies to create a scalable and flexible core platform that can be tailored to specific scientific domains. In this paper we describe the architecture of Velo for managing and associating the various types of data that are used and created in modeling and simulation projects, as well as the framework for integrating domain-specific tools. To demonstrate a realization of Velo, we describe the Geologic Sequestration Software Suite (GS3) that has been developed to support geologic sequestration modeling. This provides a concrete example of the inherent extensibility and utility of our approach.

  3. Simulations of groundwater flow and particle-tracking analysis in the zone of contribution to a public-supply well in San Antonio, Texas

    Science.gov (United States)

    Lindgren, Richard L.; Houston, Natalie A.; Musgrove, MaryLynn; Fahlquist, Lynne S.; Kauffman, Leon J.

    2011-01-01

    In 2006, a public-supply well in San Antonio, Texas, was selected for intensive study to assess the vulnerability of public-supply wells in the Edwards aquifer to contamination by a variety of compounds. A local-scale, steady-state, three-dimensional numerical groundwater-flow model was developed and used in this study to evaluate the movement of water and solutes from recharge areas to the selected public-supply well. Particle tracking was used to compute flow paths and advective traveltimes throughout the model area and to delineate the areas contributing recharge and zone of contribution for the selected public-supply well.

  4. Public Values

    DEFF Research Database (Denmark)

    Beck Jørgensen, Torben; Rutgers, Mark R.

    2015-01-01

    administration is approached in terms of processes guided or restricted by public values and as public value creating: public management and public policy-making are both concerned with establishing, following and realizing public values. To study public values a broad perspective is needed. The article suggest......This article provides the introduction to a symposium on contemporary public values research. It is argued that the contribution to this symposium represent a Public Values Perspective, distinct from other specific lines of research that also use public value as a core concept. Public...... a research agenda for this encompasing kind of public values research. Finally the contributions to the symposium are introduced....

  5. An Empirical Research on Periodic Fluctuation of Public Opinion on Microblogging and Other Domains%微博舆情跨域周期波动实证研究

    Institute of Scientific and Technical Information of China (English)

    盛宇

    2015-01-01

    Combining the period of microblogging public opinion and the period of objective factors triggering the microblogging events, this paper conducts a cross-field research on periodic fluctuation of online and offline. The paper puts forward a complete set of research ideas and research methods, and conducts an empirical research to test the feasibility of the ideas, taking the haze event on microblogging as an example. The conclusion implies the interactive rules between the periods of microblogging public opinion and objective factors, and proposes a microblogging public opinion forecasting model. The study deepens the theory of periodic microblogging public opinion, and provides a new way for the early warning of microblogging public opinion, and the paper has significant values in both theoretical and practical aspects.%以生命周期理论为基础,将微博舆情周期与触发事件客观因素周期相联系,进行线上线下的跨域周期波动研究,提出一整套研究思路和研究方法,并以微博雾霾事件为例进行实证分析,考察了思路的可行性,实证结论揭示了微博雾霾舆情周期与客观因素周期之间的互动规律,提出微博舆情预测模型。深化了微博舆情周期理论,并为微博舆情预警提供了新思路,在理论性和实用性方面都具有重要价值。

  6. Controllability of vortex domain structure in ferroelectric nanodot: fruitful domain patterns and transformation paths.

    Science.gov (United States)

    Wu, C M; Chen, W J; Zheng, Yue; Ma, D C; Wang, B; Liu, J Y; Woo, C H

    2014-02-04

    Ferroelectric vortex domain structure which exists in low-dimensional ferroelectrics is being intensively researched for future applications in functional nanodevices. Here we demonstrate that adjusting surface charge screening in combination with temperature can provide an efficient way to gain control of vortex domain structure in ferroelectric nanodot. Systematical simulating experiments have been conducted to reveal the stability and evolution mechanisms of domain structure in ferroelectric nanodot under various conditions, including processes of cooling-down/heating-up under different surface charge screening conditions, and increasing/decreasing surface charge screening at different temperatures. Fruitful phase diagrams as functions of surface screening and temperature are presented, together with evolution paths of various domain patterns. Calculations discover up to 25 different kinds of domain patterns and 22 typical evolution paths of phase transitions. The fruitful controllability of vortex domain structure by surface charge screening in combination with temperature should shed light on prospective nanodevice applications of low-dimensional ferroelectric nanostructures.

  7. Análisis de dominio de la revista mexicana Investigación Bibliotecológica Domain analysis by the mexican publication Investigación Bibliotecológica

    Directory of Open Access Journals (Sweden)

    Félix de Moya-Anegón

    2001-12-01

    Full Text Available El análisis de dominio esta compuesto por un conjunto de metodologías que permiten delinear la estructura de relaciones existente en una determinada disciplina. El objetivo del presente trabajo es brindar un análisis de dominio de la disciplina Bibliotecología y Documentación (ByD en México. Para ello se analizará la bibliografía citaa por la revista Investigación Bibliotecológica (IB. Entre los elementos a analizar se encuentran: producción, autoría, coautoría, fuentes citadas y cocitación de revistas.The domain analysis involved a set of methods that show the structure of relations in a specific discipline. The aim of this paper is to provide the domain analysis of Library and Information Science (LIS in México. For that purpose, the bibliography of the Investigación Bibliotecológica (IB journal is analized. We analize the production, autorship, co-autorship, quoted sources, and joint quotation of journals.

  8. Effects of sub-domain structure on initial magnetization curve and domain size distribution of stacked media

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S., E-mail: 231504@gmail.com; Kumagai, S.; Sugita, R.

    2015-03-01

    In this paper, in order to confirm the sub-domain structure in stacked media demagnetized with in-plane field, initial magnetization curves and magnetic domain size distribution were investigated. Both experimental and simulation results showed that an initial magnetization curve for the medium demagnetized with in-plane field (MDI) initially rose faster than that for the medium demagnetized with perpendicular field (MDP). It is inferred that this is because the MDI has a larger number of domain walls than the MDP due to the existence of the sub-domains, resulting in an increase in the probability of domain wall motion. Dispersion of domain size for the MDI was larger than that for the MDP. This is because sub-domains are formed not only inside the domain but also at the domain boundary region, and they change the position of the domain boundary to affect the domain size. - Highlights: • An initial magnetization curve for MDI initially rose faster than that for MDP. • Dispersion of domain size for the MDI was larger than that for the MDP. • Experimental and simulation results can be explained by existence of sub-domains.

  9. Public Computation & Boundary Play

    CERN Document Server

    Sengupta, Pratim

    2016-01-01

    In this paper, we introduce 'public computation' as a genre of learning environments that can be used to radically broaden public participation in authentic, computation-enabled STEM disciplinary practices. Our paradigmatic approach utilizes open source software designed for professional scientists, engineers and digital artists, and situates them in an undiluted form, alongside live and archived expert support, in a public space. We present a case study of DigiPlay, a prototypical public computation space we designed at the University of Calgary, where users can interact directly with scientific simulations as well as the underlying open source code using an array of massive multi- touch screens. We argue that in such a space, public interactions with the code can be thought of as boundary work and play, through which public participation becomes legitimate scientific act, as the public engages in scientific creation through truly open-ended explorations with the code.

  10. Collaboration Schemes Evaluation in Multi-domain Networks

    Directory of Open Access Journals (Sweden)

    Aymen Belghith

    2012-07-01

    Full Text Available The monitoring of the quality of service in a multi-domain network supervises the multi-domain service performance. A multi-domain service is a service that crosses several domains which can be managed by different providers. Since each domain can be managed with its own policies and may require confidentiality of its topology and its monitoring processes, we propose that the monitoring architecture has to be configurable. In this paper, we propose two collaboration schemes that are based on the reactive and the proactive modes. Both of collaboration schemes allow the multi-domain monitoring architecture to select the measurement points that will participate in the multi-domain monitoring and to configure the selected measurement points. In this paper, we present our proposed collaboration schemes and then we evaluate their performance through extensive simulations using Network Simulator (NS-2.

  11. Translation domains in multiferroics

    OpenAIRE

    Meier, D; Leo, N; Jungk, T.; Soergel, E.; Becker, P.; Bohaty, L.; Fiebig, M.

    2010-01-01

    Translation domains differing in the phase but not in the orientation of the corresponding order parameter are resolved in two types of multiferroics. Hexagonal (h-) YMnO$_3$ is a split-order-parameter multiferroic in which commensurate ferroelectric translation domains are resolved by piezoresponse force microscopy whereas MnWO$_4$ is a joint-order-parameter multiferroic in which incommensurate magnetic translation domains are observed by optical second harmonic generation. The pronounced ma...

  12. Frustratingly Easy Domain Adaptation

    CERN Document Server

    Daumé, Hal

    2009-01-01

    We describe an approach to domain adaptation that is appropriate exactly in the case when one has enough ``target'' data to do slightly better than just using only ``source'' data. Our approach is incredibly simple, easy to implement as a preprocessing step (10 lines of Perl!) and outperforms state-of-the-art approaches on a range of datasets. Moreover, it is trivially extended to a multi-domain adaptation problem, where one has data from a variety of different domains.

  13. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  14. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  15. Visualizing domain wall and reverse domain superconductivity.

    Science.gov (United States)

    Iavarone, M; Moore, S A; Fedor, J; Ciocys, S T; Karapetrov, G; Pearson, J; Novosad, V; Bader, S D

    2014-08-28

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application.

  16. Electric-field-driven dynamics of magnetic domain walls in magnetic nanowires patterned on ferroelectric domains

    Science.gov (United States)

    Van de Wiele, Ben; Leliaert, Jonathan; Franke, Kévin J. A.; van Dijken, Sebastiaan

    2016-03-01

    Strong coupling of magnetic domain walls onto straight ferroelastic boundaries of a ferroelectric layer enables full and reversible electric-field control of magnetic domain wall motion. In this paper, the dynamics of this new driving mechanism is analyzed using micromagnetic simulations. We show that transverse domain walls with a near-180° spin structure are stabilized in magnetic nanowires and that electric fields can move these walls with high velocities. Above a critical velocity, which depends on material parameters, nanowire geometry and the direction of domain wall motion, the magnetic domain walls depin abruptly from the ferroelastic boundaries. Depinning evolves either smoothly or via the emission and annihilation of a vortex or antivortex core (Walker breakdown). In both cases, the magnetic domain wall slows down after depinning in an oscillatory fashion and eventually comes to a halt. The simulations provide design rules for hybrid ferromagnetic-ferroelectric domain-wall-based devices and indicate that material disorder and structural imperfections only influence Walker-breakdown-like depinning at high domain wall velocities.

  17. Learning from and for rare floods in Dresden – how public officials interpret damage simulation results at the building type level

    Directory of Open Access Journals (Sweden)

    Hutter Gerard

    2016-01-01

    Full Text Available Public officials in Dresden are concerned about learning from and for rare flood events like the Elbe river flood in August 2002. This is interesting because research on individual as well as organizational learning from rare events indicates that this kind of learning faces significant difficulties (e.g., overestimation of rare events for decision-making based on “emotionalized event experience”. Up to now, only little is known what and how public officials in Dresden specifically learn from and for rare floods. Therefore, the paper follows an exploratory purpose in line with principles of qualitative social research. Firstly, the paper explores dealing with rare floods with reference to a conceptual framework that highlights relations between regulative, normative, and cognitive institutions on the one hand and learning of public officials on the other. Secondly, it adopts a single case study design in Dresden with embedded sub-cases that are defined with reference to organizations of FRM. The case study shows, among others, that regulations like the Floods Directive are important for justifying FRM with regard to rare flood events which is less obvious than it sounds. However, public officials display different interpretations of the term “rare flood event”, for instance, in the context of analysing the consequences of floods on the building stock. Furthermore, the case study findings indicate that public officials may follow alternative approaches to sustain commitment in the context of rare flood events (systematic versus pragmatic approach.

  18. Domain Relaxation in Langmuir Films

    Science.gov (United States)

    Bernoff, Andrew J.; Alexander, James C.; Mann, Elizabeth K.; Mann, J. Adin; Zou, Lu; Wintersmith, Jacob R.

    2007-11-01

    We report on an experimental, theoretical and computational study of a molecularly thin polymer Langmuir layer domain on the surface of a subfluid. When stretched (by a transient stagnation flow), the Langmuir layer takes the form of a bola consisting of two roughly circular reservoirs connected by a thin tether. This shape relaxes to the circular minimum energy configuration. The tether is never observed to rupture, even when it is more than a hundred times as long as it is thin. We model these experiments as a free boundary problem where motion is driven by the line tension of the domain and damped by the viscosity of the subfluid. We process the digital images of the experiment to extract the domain shape, use one of these shapes as an initial condition for the numerical solution of a boundary-integral model of the underlying hydrodynamics, and compare the subsequent images of the experiment to the numerical simulation. The numerical evolutions verify that our hydrodynamical model can reproduce the observed dynamics. They also allow us to deduce the magnitude of the line tension in the system, often to within 1%.

  19. A SIMPLIFIED MODEL FOR DOMAIN SWITCHING OF FERROELECTRIC CRYSTAL

    Institute of Scientific and Technical Information of China (English)

    HeYansong; FanJinghong

    2004-01-01

    Domain switching is the main source of nonlinear characteristics in ferroelectrics. According to crystal plasticity theory, the domains and domain switching systems for perovskitetype structure ferroelectrics are defined. Considering the traverse motion performance of domain wall, a rather simplified form of evolution law about incremental of volume fraction during domain switching has been developed. The main factors, which exert an influence on domain switching, such as material parameters, domain wall motion history, kind of domain switching (180° or 90°) and volume fraction, could be addressed. The hysteresis loops of spontaneous electric polarization as a function of electric field, the butterfly shaped strain versus electric field curve and the platform relations between spontaneous polarization and stress, as well as the longitudinal strain and stress, are well simulated and discussed.

  20. Acoustic Treatment Design Scaling Methods. Volume 4; Numerical Simulation of the Nonlinear Acoustic Impedance of a Perforated Plate Single-Degree-of-Freedom Resonator Using a Time-Domain Finite Difference Method

    Science.gov (United States)

    Kraft, R. E.

    1999-01-01

    Single-degree-of-freedom resonators consisting of honeycomb cells covered by perforated facesheets are widely used as acoustic noise suppression liners in aircraft engine ducts. The acoustic resistance and mass reactance of such liners are known to vary with the intensity of the sound incident upon the panel. Since the pressure drop across a perforated liner facesheet increases quadratically with the flow velocity through the facesheet, this is known as the nonlinear resistance effect. In the past, two different empirical frequency domain models have been used to predict the Sound Pressure Level effect of the incident wave on the perforated liner impedance, one that uses the incident particle velocity in isolated narrowbands, and one that models the particle velocity as the overall velocity. In the absence of grazing flow, neither frequency domain model is entirely accurate in predicting the nonlinear effect that is measured for typical perforated sheets. The time domain model is developed in an attempt to understand and improve the model for the effect of spectral shape and amplitude of multi-frequency incident sound pressure on the liner impedance. A computer code for the time-domain finite difference model is developed and predictions using the models are compared to current frequency-domain models.

  1. The enterprise engineering domain

    CSIR Research Space (South Africa)

    De Vries, M

    2015-06-01

    Full Text Available representation of the EE domain within the emerging EE discipline. We used a questionnaire to gather the views of EE and enterprise architecture (EA) researchers and practitioners on the EE domain. The main contributions of this article include: (1...

  2. Domain wall filters

    CERN Document Server

    Bär, O; Neuberger, H; Witzel, O; Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-01-01

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  3. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  4. Domains of Learning.

    Science.gov (United States)

    Gagne, Robert M.

    In planning educational research, recognition needs to be made of five domains of learning: (1) motor skills, (2) verbal information, (3) intellectual skills, (4) cognitive strategies, and (5) attitudes. In being cognizant of these domains, the researcher is able to distinguish the parts of a content area which are subject to different…

  5. A Domain Analysis Bibliography

    Science.gov (United States)

    1990-06-01

    Bauhaus , a prototype CASE workstation for D-SAPS development. [ARAN88A] Guillermo F. Arango. Domain Engineering for Software Reuse. PhD thesis...34 VITA90B: Domain Analysis within the ISEC Rapid Center 48 CMU/SEI-90-SR-3 Appendix III Alphabetical by Organization/Project BAUHAUS * ALLE87A

  6. Contribution of the CR domain to P-selectin lectin domain allostery by regulating the orientation of the EGF domain.

    Science.gov (United States)

    Lü, Shouqin; Chen, Shenbao; Mao, Debin; Zhang, Yan; Long, Mian

    2015-01-01

    The allostery of P-selectin has been studied extensively with a focus on the Lec and EGF domains, whereas the contribution of the CR domain remains unclear. Here, molecular dynamics simulations (MDS) combined with homology modeling were preformed to investigate the impact of the CR domain on P-selectin allostery. The results indicated that the CR domain plays a role in the allosteric dynamics of P-selectin in two ways. First, the CR1 domain tends to stabilize the low affinity of P-selectin during the equilibration processes with the transition inhibition from the S1 to S1' state by restraining the extension of the bent EGF orientation, or with the relaxation acceleration of the S2 state by promoting the bending of the extended EGF orientation. Second, the existence of CR domain increases intramolecular extension prior to complex separation, increasing the time available for the allosteric shift during forced dissociation with a prolonged bond duration. These findings further our understanding of the structure-function relationship of P-selectin with the enriched micro-structural bases of the CR domain.

  7. Effects of Landau-Lifshitz-Gilbert damping on domain growth.

    Science.gov (United States)

    Kudo, Kazue

    2016-12-01

    Domain patterns are simulated by the Landau-Lifshitz-Gilbert (LLG) equation with an easy-axis anisotropy. If the Gilbert damping is removed from the LLG equation, it merely describes the precession of magnetization with a ferromagnetic interaction. However, even without the damping, domains that look similar to those of scalar fields are formed, and they grow with time. It is demonstrated that the damping has no significant effects on domain growth laws and large-scale domain structure. In contrast, small-scale domain structure is affected by the damping. The difference in small-scale structure arises from energy dissipation due to the damping.

  8. Effects of Landau-Lifshitz-Gilbert damping on domain growth

    Science.gov (United States)

    Kudo, Kazue

    2016-12-01

    Domain patterns are simulated by the Landau-Lifshitz-Gilbert (LLG) equation with an easy-axis anisotropy. If the Gilbert damping is removed from the LLG equation, it merely describes the precession of magnetization with a ferromagnetic interaction. However, even without the damping, domains that look similar to those of scalar fields are formed, and they grow with time. It is demonstrated that the damping has no significant effects on domain growth laws and large-scale domain structure. In contrast, small-scale domain structure is affected by the damping. The difference in small-scale structure arises from energy dissipation due to the damping.

  9. Public lighting.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1986-01-01

    The function of public lighting and the relationship between public lighting and accidents are considered briefly as aspects of effective countermeasures. Research needs and recent developments in installation and operational described. Public lighting is an efficient accident countermeasure, but

  10. Scalable Domain Decomposed Monte Carlo Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Matthew Joseph [Univ. of California, Davis, CA (United States)

    2013-12-05

    In this dissertation, we present the parallel algorithms necessary to run domain decomposed Monte Carlo particle transport on large numbers of processors (millions of processors). Previous algorithms were not scalable, and the parallel overhead became more computationally costly than the numerical simulation.

  11. 基于系统动力学的网络舆情风险模型仿真研究%Research on Modeling and Simulation of Risk of Internet Public Opinion Based on System Dynamics

    Institute of Scientific and Technical Information of China (English)

    高航; 丁荣贵

    2014-01-01

    Network dissemination has the features of high-speed, interaction and wide-ranging. The rising risk of public opinion in the promotion of network dissemination would negatively affect social stability. This paper analyzes the various influences on risk of internet public opinion of diffusion efficiency of information, transmission capacity of subject, action level of network media and resonance degree of audience, and conducts a simulation based on the system dynamics model built around the above-mentioned dimensions applying Ven-sim PLE. The simulation results show that public opinion sensitivity, activity level of subject, influence of media and participation degree of audience have important influence on risk of internet public opinion.%舆情事件在网络传播的迅捷性、互动性与广泛性等特征催化下,风险不断上升,对社会稳定造成重大负面影响。鉴于网络舆情风险是多因素互动的结果,从舆情信息扩散效率、舆情主体传播能力、网络媒体作用水平、舆情受众共鸣程度等模块建立了系统动力学模型,并利用Vensim PLE进行了模拟仿真。仿真结果表明,舆情敏感度、主体活跃度、媒体影响力、受众参与度等变量与网络舆情风险存在较强互动关系,能够对后者产生较大影响。

  12. Robust phase-domain transmission line representation based on time-domain fitting

    Energy Technology Data Exchange (ETDEWEB)

    Nobre, Diana M.; Neves, Washington L.A. [Federal University of Campina Grande (UFCG), Electrical Engineering Department, Av Aprigio Veloso, 882 Campina Grande, PB 58.109-970 (Brazil); Boaventura, Wallace do C. [Federal University of Minas Gerais (UFMG), Electrical Engineering Department, Av Antonio Carlos, 6627 Pampulha, Belo Horizonte, MG 31.270-010 (Brazil)

    2006-05-15

    This work presents a methodology for deriving a phase-domain transmission line representation based on time-domain fitting. A polynomial matrix in the discrete-time domain describes the resulting model. The robustness of the representation, its stability and passivity, is attained by imbedding a set of constraints in the solution of the fitting equations, which are solved using quadratic programming. Results demonstrating from transient simulations the features of the derived representation are presented for the case of an asymmetric, untransposed two-phase transmission line. (author)

  13. Public Broadcasting.

    Science.gov (United States)

    Shooshan, Harry M.; Arnheim, Louise

    This paper, the second in a series exploring future options for public policy in the communications and information arenas, examines some of the issues underlying public broadcasting, primarily public television. It advances two reasons why quality local public television programming is scarce: funds for the original production of programming have…

  14. A Survey on Domain-Specific Languages in Robotics

    OpenAIRE

    Nordmann, Arne; Hochgeschwender, Nico; Wrede, Sebastian

    2014-01-01

    The design, simulation and programming of robotics systems is challenging as expertise from multiple domains needs to be integrated conceptually and technically. Domain-specific modeling promises an efficient and flexible concept for developing robotics applications that copes with this challenge. It allows to raise the level of abstraction through the use of specific concepts that are closer to the respective domain concerns and easier to understand and validate. Furthermore, it focuses on i...

  15. Domain-Specific Multimodeling

    DEFF Research Database (Denmark)

    Hessellund, Anders

    Enterprise systems are complex artifacts. They are hard to build, manage, understand, and evolve. Existing software development paradigms fail to properly address challenges such as system size, domain complexity, and software evolution when development is scaled to enterprise systems. We propose...... domain-specific multimodeling as a development paradigm to tackle these challenges in a language-oriented manner. The different concerns of a system are conceptually separated and made explicit as independent domain-specific languages. This approach increases productivity and quality by raising...... the overall level of abstraction. It does, however, also introduce a new problem of coordinating multiple different languages in a single system. We call this problem the coordination problem. In this thesis, we present the coordination method for domain-specific multimodeling that explicitly targets...

  16. Conserved Domain Database (CDD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — CDD is a protein annotation resource that consists of a collection of well-annotated multiple sequence alignment models for ancient domains and full-length proteins.

  17. A Parametric Abstract Domain for Lattice-Valued Regular Expressions

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    We present a lattice-valued generalization of regular expressions as an abstract domain for static analysis. The parametric abstract domain rests on a generalization of Brzozowski derivatives and works for both finite and infinite lattices. We develop both a co-inductive, simulation algorithm...

  18. Analysis of Thermally Denatured Depth in Laser Vaporization for Benign Prostatic Hyperplasia using a Simulation of Light Propagation and Heat Transfer (secondary publication).

    Science.gov (United States)

    Takada, Junya; Honda, Norihiro; Hazama, Hisanao; Ioritani, Naomasa; Awazu, Kunio

    2016-12-30

    Background and Aims: Laser vaporization of the prostate is expected as a less invasive treatment for benign prostatic hyperplasia (BPH), via the photothermal effect. In order to develop safer and more effective laser vaporization of the prostate, it is essential to set optimal irradiation parameters based on quantitative evaluation of temperature distribution and thermally denatured depth in prostate tissue. Method: A simulation model was therefore devised with light propagation and heat transfer calculation, and the vaporized and thermally denatured depths were estimated by the simulation model. Results: The results of the simulation were compared with those of an ex vivo experiment and clinical trial. Based on the accumulated data, the vaporized depth strongly depended on the distance between the optical fiber and the prostate tissue, and it was suggested that contact laser irradiation could vaporize the prostate tissue most effectively. Additionally, it was suggested by analyzing thermally denatured depth comprehensively that laser irradiation at the distance of 3 mm between the optical fiber and the prostate tissue was useful for hemostasis. Conclusions: This study enabled quantitative and reproducible analysis of laser vaporization for BPH and will play a role in clarification of the safety and efficacy of this treatment.

  19. Simulation of the respiratory model of tract of Publication 66 of the ICRP and their use in biological analysis; Simulacion del modelo de tracto respiratorio de la Publicacion 66 de la ICRP y su utilizacion en bioanalisis

    Energy Technology Data Exchange (ETDEWEB)

    Puerta, A. [Universidad Nacional de Colombia, Medellin (Colombia). Facultad de Ciencias. Dept. de Fisica; Bertelli, L.; Lipsztein, J. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

    2001-07-01

    The International Commission Radiological Protection, ICRP in its publications 67, 68, 69 and 71 provides the loss of systematic activity of the radioactive materials by the routes of excretion and recirculation, as well as effective dose by incorporation unit coefficient, using the model of respiratory tract proposed by the ICRP, in its Publication 66, but it does not provide information on as these models in biological analysis are used. There are some specific studies for inhalation of uranium compounds made by Bertelli and collaborators using the new model of the lung. In this work it have been done a simulation of the model of respiratory tract of ICRP 66 of such form that it can be used in-vitro and in-vivo biological analysis. In order to verify the simulation were used systemic models for adult of planuin, lead, uranium, bismuth and their respective descendants and the comparison with the coefficients of dose provided by the ICRP. Finally, it shows the estimation of the temporary distribution of activity in devices and the excrete of these radionuclides and in addition the model for gases and steam in the conditions is verified that the ICRP proposes.

  20. Strongly Semicontinuous Domains and Semi-FS Domains

    Directory of Open Access Journals (Sweden)

    Qingyu He

    2014-01-01

    Full Text Available We are mainly concerned with some special kinds of semicontinuous domains and relationships between them. New concepts of strongly semicontinuous domains, meet semicontinuous domains and semi-FS domains are introduced. It is shown that a dcpo L is strongly semicontinuous if and only if L is semicontinuous and meet semicontinuous. It is proved that semi-FS domains are strongly semicontinuous. Some interpolation properties of semiway-below relations in (strongly semicontinuous bc-domains are given. In terms of these properties, it is proved that strongly semicontinuous bc-domains, in particular strongly semicontinuous lattices, are all semi-FS domains.

  1. Time domain modeling of tunable response of graphene

    DEFF Research Database (Denmark)

    Prokopeva, Ludmila; Emani, Naresh K.; Boltasseva, Alexandra

    2013-01-01

    We present a causal numerical model for time domain simulations of the optical response of graphene. The dielectric function is approximated with a conductivity term, a Drude term and a number of the critical points terms.......We present a causal numerical model for time domain simulations of the optical response of graphene. The dielectric function is approximated with a conductivity term, a Drude term and a number of the critical points terms....

  2. Simulation in Undergraduate Psychiatry: Exploring the Depth of Learner Engagement.

    Science.gov (United States)

    Abdool, Petal S; Nirula, Latika; Bonato, Sarah; Rajji, Tarek K; Silver, Ivan L

    2017-04-01

    Simulation-based methodologies are increasingly used in undergraduate medical education to expand students' exposure to complex clinical scenarios. Engagement of students in these simulation-based methodologies is a key determinant of their success in learning. Thus, the authors conducted a systematic review to (1) identify simulation methods in use within the undergraduate psychiatry curriculum and (2) assess learner engagement using these methods. Following a PRISMA methodology, the authors searched MEDLINE, ERIC, and PsychINFO databases from 1977 to 2015. Studies applying simulation in undergraduate psychiatric education were reviewed. The depth of learner engagement was assessed using Kolb's four-stage learning cycle. Of 371 publications identified, 63 met all the inclusion criteria: 48 used standardized patients and 16 used online or virtual learning case modules. Only one study used high fidelity mannequins. Three studies satisfied multiple stages in Kolb's Learning Cycle, including a single study that addressed all four domains. Despite the varied uses of simulation across other health disciplines, there were few novel or innovative uses of simulation in undergraduate psychiatric education since the last review in 2008. Expanding on the use of simulation to improve communication, build empathy, and decrease stigma in psychiatry is essential given the relevance to all facets of medical practice. Given the complexity of psychiatry, simulation interventions should extend beyond communication scenarios. Medical students need more opportunities to reflect and debrief on simulation experiences and integrate learning into new contexts. Faculty development should focus on these novel approaches to simulation to deeply engage learners and enhance outcomes.

  3. Suspension parameter estimation in the frequency domain using a matrix inversion approach

    Science.gov (United States)

    Thite, A. N.; Banvidi, S.; Ibicek, T.; Bennett, L.

    2011-12-01

    The dynamic lumped parameter models used to optimise the ride and handling of a vehicle require base values of the suspension parameters. These parameters are generally experimentally identified. The accuracy of identified parameters can depend on the measurement noise and the validity of the model used. The existing publications on suspension parameter identification are generally based on the time domain and use a limited degree of freedom. Further, the data used are either from a simulated 'experiment' or from a laboratory test on an idealised quarter or a half-car model. In this paper, a method is developed in the frequency domain which effectively accounts for the measurement noise. Additional dynamic constraining equations are incorporated and the proposed formulation results in a matrix inversion approach. The nonlinearities in damping are estimated, however, using a time-domain approach. Full-scale 4-post rig test data of a vehicle are used. The variations in the results are discussed using the modal resonant behaviour. Further, a method is implemented to show how the results can be improved when the matrix inverted is ill-conditioned. The case study shows a good agreement between the estimates based on the proposed frequency-domain approach and measurable physical parameters.

  4. Domains in Ferroelectric Nanostructures

    Science.gov (United States)

    Gregg, Marty

    2010-03-01

    Ferroelectric materials have great potential in influencing the future of small scale electronics. At a basic level, this is because ferroelectric surfaces are charged, and so interact strongly with charge-carrying metals and semiconductors - the building blocks for all electronic systems. Since the electrical polarity of the ferroelectric can be reversed, surfaces can both attract and repel charges in nearby materials, and can thereby exert complete control over both charge distribution and movement. It should be no surprise, therefore, that microelectronics industries have already looked very seriously at harnessing ferroelectric materials in a variety of applications, from solid state memory chips (FeRAMs) to field effect transistors (FeFETs). In all such applications, switching the direction of the polarity of the ferroelectric is a key aspect of functional behavior. The mechanism for switching involves the field-induced nucleation and growth of domains. Domain coarsening, through domain wall propagation, eventually causes the entire ferroelectric to switch its polar direction. It is thus the existence and behavior of domains that determine the switching response, and ultimately the performance of the ferroelectric device. A major issue, associated with the integration of ferroelectrics into microelectronic devices, has been that the fundamental properties associated with ferroelectrics, when in bulk form, appear to change quite dramatically and unpredictably when at the nanoscale: new modes of behaviour, and different functional characteristics from those seen in bulk appear. For domains, in particular, the proximity of surfaces and boundaries have a dramatic effect: surface tension and depolarizing fields both serve to increase the equilibrium density of domains, such that minor changes in scale or morphology can have major ramifications for domain redistribution. Given the importance of domains in dictating the overall switching characteristics of a device

  5. Load Estimation by Frequency Domain Decomposition

    DEFF Research Database (Denmark)

    Pedersen, Ivar Chr. Bjerg; Hansen, Søren Mosegaard; Brincker, Rune;

    2007-01-01

    When performing operational modal analysis the dynamic loading is unknown, however, once the modal properties of the structure have been estimated, the transfer matrix can be obtained, and the loading can be estimated by inverse filtering. In this paper loads in frequency domain are estimated...... by analysis of simulated responses of a 4 DOF system, for which the exact modal parameters are known. This estimation approach entails modal identification of the natural eigenfrequencies, mode shapes and damping ratios by the frequency domain decomposition technique. Scaled mode shapes are determined by use...

  6. Structured hints : extracting and abstracting domain expertise.

    Energy Technology Data Exchange (ETDEWEB)

    Hereld, M.; Stevens, R.; Sterling, T.; Gao, G. R.; Mathematics and Computer Science; California Inst. of Tech.; Louisiana State Univ.; Univ. of Delaware

    2009-03-16

    We propose a new framework for providing information to help optimize domain-specific application codes. Its design addresses problems that derive from the widening gap between the domain problem statement by domain experts and the architectural details of new and future high-end computing systems. The design is particularly well suited to program execution models that incorporate dynamic adaptive methodologies for live tuning of program performance and resource utilization. This new framework, which we call 'structured hints', couples a vocabulary of annotations to a suite of performance metrics. The immediate target is development of a process by which a domain expert describes characteristics of objects and methods in the application code that would not be readily apparent to the compiler; the domain expert provides further information about what quantities might provide the best indications of desirable effect; and the interactive preprocessor identifies potential opportunities for the domain expert to evaluate. Our development of these ideas is progressing in stages from case study, through manual implementation, to automatic or semi-automatic implementation. In this paper we discuss results from our case study, an examination of a large simulation of a neural network modeled after the neocortex.

  7. Mechanical Properties of Nanoscopic Lipid Domains.

    Science.gov (United States)

    Nickels, Jonathan D; Cheng, Xiaolin; Mostofian, Barmak; Stanley, Christopher; Lindner, Benjamin; Heberle, Frederick A; Perticaroli, Stefania; Feygenson, Mikhail; Egami, Takeshi; Standaert, Robert F; Smith, Jeremy C; Myles, Dean A A; Ohl, Michael; Katsaras, John

    2015-12-23

    The lipid raft hypothesis presents insights into how the cell membrane organizes proteins and lipids to accomplish its many vital functions. Yet basic questions remain about the physical mechanisms that lead to the formation, stability, and size of lipid rafts. As a result, much interest has been generated in the study of systems that contain similar lateral heterogeneities, or domains. In the current work we present an experimental approach that is capable of isolating the bending moduli of lipid domains. This is accomplished using neutron scattering and its unique sensitivity to the isotopes of hydrogen. Combining contrast matching approaches with inelastic neutron scattering, we isolate the bending modulus of ∼13 nm diameter domains residing in 60 nm unilamellar vesicles, whose lipid composition mimics the mammalian plasma membrane outer leaflet. Importantly, the bending modulus of the nanoscopic domains differs from the modulus of the continuous phase surrounding them. From additional structural measurements and all-atom simulations, we also determine that nanoscopic domains are in-register across the bilayer leaflets. Taken together, these results inform a number of theoretical models of domain/raft formation and highlight the fact that mismatches in bending modulus must be accounted for when explaining the emergence of lateral heterogeneities in lipid systems and biological membranes.

  8. User interfaces for computational science: A domain specific language for OOMMF embedded in Python

    Science.gov (United States)

    Beg, Marijan; Pepper, Ryan A.; Fangohr, Hans

    2017-05-01

    Computer simulations are used widely across the engineering and science disciplines, including in the research and development of magnetic devices using computational micromagnetics. In this work, we identify and review different approaches to configuring simulation runs: (i) the re-compilation of source code, (ii) the use of configuration files, (iii) the graphical user interface, and (iv) embedding the simulation specification in an existing programming language to express the computational problem. We identify the advantages and disadvantages of different approaches and discuss their implications on effectiveness and reproducibility of computational studies and results. Following on from this, we design and describe a domain specific language for micromagnetics that is embedded in the Python language, and allows users to define the micromagnetic simulations they want to carry out in a flexible way. We have implemented this micromagnetic simulation description language together with a computational backend that executes the simulation task using the Object Oriented MicroMagnetic Framework (OOMMF). We illustrate the use of this Python interface for OOMMF by solving the micromagnetic standard problem 4. All the code is publicly available and is open source.

  9. Recovering protein-protein and domain-domain interactions from aggregation of IP-MS proteomics of coregulator complexes.

    Directory of Open Access Journals (Sweden)

    Amin R Mazloom

    2011-12-01

    Full Text Available Coregulator proteins (CoRegs are part of multi-protein complexes that transiently assemble with transcription factors and chromatin modifiers to regulate gene expression. In this study we analyzed data from 3,290 immuno-precipitations (IP followed by mass spectrometry (MS applied to human cell lines aimed at identifying CoRegs complexes. Using the semi-quantitative spectral counts, we scored binary protein-protein and domain-domain associations with several equations. Unlike previous applications, our methods scored prey-prey protein-protein interactions regardless of the baits used. We also predicted domain-domain interactions underlying predicted protein-protein interactions. The quality of predicted protein-protein and domain-domain interactions was evaluated using known binary interactions from the literature, whereas one protein-protein interaction, between STRN and CTTNBP2NL, was validated experimentally; and one domain-domain interaction, between the HEAT domain of PPP2R1A and the Pkinase domain of STK25, was validated using molecular docking simulations. The scoring schemes presented here recovered known, and predicted many new, complexes, protein-protein, and domain-domain interactions. The networks that resulted from the predictions are provided as a web-based interactive application at http://maayanlab.net/HT-IP-MS-2-PPI-DDI/.

  10. Just how versatile are domains?

    Directory of Open Access Journals (Sweden)

    Bornberg-Bauer Erich

    2008-10-01

    Full Text Available Abstract Background Creating new protein domain arrangements is a frequent mechanism of evolutionary innovation. While some domains always form the same combinations, others form many different arrangements. This ability, which is often referred to as versatility or promiscuity of domains, its a random evolutionary model in which a domain's promiscuity is based on its relative frequency of domains. Results We show that there is a clear relationship across genomes between the promiscuity of a given domain and its frequency. However, the strength of this relationship differs for different domains. We thus redefine domain promiscuity by defining a new index, DV I ("domain versatility index", which eliminates the effect of domain frequency. We explore links between a domain's versatility, when unlinked from abundance, and its biological properties. Conclusion Our results indicate that domains occurring as single domain proteins and domains appearing frequently at protein termini have a higher DV I. This is consistent with previous observations that the evolution of domain re-arrangements is primarily driven by fusion of pre-existing arrangements and single domains as well as loss of domains at protein termini. Furthermore, we studied the link between domain age, defined as the first appearance of a domain in the species tree, and the DV I. Contrary to previous studies based on domain promiscuity, it seems as if the DV I is age independent. Finally, we find that contrary to previously reported findings, versatility is lower in Eukaryotes. In summary, our measure of domain versatility indicates that a random attachment process is sufficient to explain the observed distribution of domain arrangements and that several views on domain promiscuity need to be revised.

  11. Public Schools

    Data.gov (United States)

    Department of Homeland Security — This Public Schools feature dataset is composed of all Public elementary and secondary education in the United States as defined by the Common Core of Data, National...

  12. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  13. Public lighting.

    NARCIS (Netherlands)

    2011-01-01

    Visual perception is very important for road users and in the dark it can be facilitated by public lighting. Public lighting has a mostly positive road safety effect. Installing public lighting on roads that were previously unlit generally results in fewer and less serious crashes. This effect seems

  14. Withdrawal of Public Lands for Wildlife Purposes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A recent BLM survey has determined that the 45.33-acre Pig Island, located in St. Joseph Bay, Gulf County, Florida, is public domain. The island has an unusual...

  15. Introduction to the Paradigm Struggle in Public Relations.

    Science.gov (United States)

    Botan, Carl

    1993-01-01

    Describes the ongoing state of change in the domain of public relations, with special attention to model shifts. Defines model struggles and discusses the emergence of international public relations along with other recent trends. (HB)

  16. Evolution of domain wall networks: the PRS algorithm

    CERN Document Server

    Sousa, L

    2011-01-01

    The Press-Ryden-Spergel (PRS) algorithm is a modification to the field theory equations of motion, parametrized by two parameters ($\\alpha$ and $\\beta$), implemented in numerical simulations of cosmological domain wall networks, in order to ensure a fixed comoving resolution. In this paper we explicitly demonstrate that the PRS algorithm provides the correct domain wall dynamics in $N+1$-dimensional Friedmann-Robertson-Walker (FRW) universes if $\\alpha+\\beta/2=N$, fully validating its use in numerical studies of cosmic domain evolution. We further show that this result is valid for generic thin featureless domain walls, independently of the Lagrangian of the model.

  17. Domain wall stability in ferroelectrics with space charges

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Yinan, E-mail: zuo@mfm.tu-darmstadt.de; Genenko, Yuri A.; Klein, Andreas; Stein, Peter; Xu, Baixiang [Institute of Materials Science, Technische Universität Darmstadt, D-64287 Darmstadt (Germany)

    2014-02-28

    Significant effect of semiconductor properties on domain configurations in ferroelectrics is demonstrated, especially in the case of doped materials. Phase field simulations are performed for ferroelectrics with space charges due to donors and electronic charge carriers. The free charges introduced thereby can act as a source for charge compensation at domain walls with uncompensated polarization bound charges. Results indicate that the equilibrium position of a domain wall with respect to its rotation in a head-to-head or a tail-to-tail domain configuration depends on the charge defect concentration and the Fermi level position.

  18. Effective pinning energy landscape perturbations for propagating magnetic domain walls

    Science.gov (United States)

    Burn, D. M.; Atkinson, D.

    2016-01-01

    The interaction between a magnetic domain wall and a pinning site is explored in a planar nanowire using micromagnetics to reveal perturbations of the pinning energetics for propagating domain walls. Numerical simulations in the high damping ’quasi-static’ and low damping ’dynamic’ regimes are compared and show clear differences in de-pinning fields, indicating that dynamical micromagnetic models, which incorporate precessionally limited magnetization processes, are needed to understand domain wall pinning. Differences in the micromagnetic domain wall structure strongly influence the pinning and show periodic behaviour with increasing applied field associated with Walker breakdown. In the propagating regime pinning is complicated. PMID:27694953

  19. Time-domain radio pulses from particle showers

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Muniz, Jaime [Depto. de Fisica de Particulas and Instituto Galego de Fisica de Altas Enerxias, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Romero-Wolf, Andres, E-mail: rw.andres@gmail.com [Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Zas, Enrique [Depto. de Fisica de Particulas and Instituto Galego de Fisica de Altas Enerxias, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2012-01-11

    The time-domain properties of the far-field coherent radio emission from electromagnetic showers are studied in depth. A purely time-domain technique for mapping the electromagnetic fields of charged tracks is developed. The method is applied to the ZHS shower code to produce electric fields. It is demonstrated that the technique is equivalent to the frequency domain methods used in the ZHS code and produces consistent results. In addition, a model for mapping the longitudinal charge profile of a shower to a time-domain electromagnetic field is developed. It is shown that the model is in good agreement to the results of shower simulation.

  20. 41 CFR 102-173.10 - What is the authority or jurisdiction of the Internet GOV Domain?

    Science.gov (United States)

    2010-07-01

    ... jurisdiction of the Internet GOV Domain? 102-173.10 Section 102-173.10 Public Contracts and Property Management... TELECOMMUNICATIONS 173-INTERNET GOV DOMAIN General § 102-173.10 What is the authority or jurisdiction of the Internet GOV Domain? Jurisdiction of the Internet GOV (dot-gov) domain was delegated to the General...