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

Path integral hybrid Monte Carlo algorithm for correlated Bose fluids.  

PubMed

Path integral hybrid Monte Carlo (PIHMC) algorithm for strongly correlated Bose fluids has been developed. This is an extended version of our previous method [S. Miura and S. Okazaki, Chem. Phys. Lett. 308, 115 (1999)] applied to a model system consisting of noninteracting bosons. Our PIHMC method for the correlated Bose fluids is constituted of two trial moves to sample path-variables describing system coordinates along imaginary time and a permutation of particle labels giving a boundary condition with respect to imaginary time. The path-variables for a given permutation are generated by a hybrid Monte Carlo method based on path integral molecular dynamics techniques. Equations of motion for the path-variables are formulated on the basis of a collective coordinate representation of the path, staging variables, to enhance the sampling efficiency. The permutation sampling to satisfy Bose-Einstein statistics is performed using the multilevel Metropolis method developed by Ceperley and Pollock [Phys. Rev. Lett. 56, 351 (1986)]. Our PIHMC method has successfully been applied to liquid helium-4 at a state point where the system is in a superfluid phase. Parameters determining the sampling efficiency are optimized in such a way that correlation among successive PIHMC steps is minimized. PMID:15268354

Miura, Shinichi; Tanaka, Junji

2004-02-01

2

Rotational fluctuation of molecules in quantum clusters. I. Path integral hybrid Monte Carlo algorithm.  

PubMed

In this paper, we present a path integral hybrid Monte Carlo (PIHMC) method for rotating molecules in quantum fluids. This is an extension of our PIHMC for correlated Bose fluids [S. Miura and J. Tanaka, J. Chem. Phys. 120, 2160 (2004)] to handle the molecular rotation quantum mechanically. A novel technique referred to be an effective potential of quantum rotation is introduced to incorporate the rotational degree of freedom in the path integral molecular dynamics or hybrid Monte Carlo algorithm. For a permutation move to satisfy Bose statistics, we devise a multilevel Metropolis method combined with a configurational-bias technique for efficiently sampling the permutation and the associated atomic coordinates. Then, we have applied the PIHMC to a helium-4 cluster doped with a carbonyl sulfide molecule. The effects of the quantum rotation on the solvation structure and energetics were examined. Translational and rotational fluctuations of the dopant in the superfluid cluster were also analyzed. PMID:17381207

Miura, Shinichi

2007-03-21

3

A Novel Multiple-Time Scale Integrator for the Hybrid Monte Carlo Algorithm  

NASA Astrophysics Data System (ADS)

Hybrid Monte Carlo simulations that implement the fermion action using multiple terms are commonly used. By the nature of their formulation they involve multiple integration time scales in the evolution of the system through simulation time. These different scales are usually dealt with by the Sexton-Weingarten nested leapfrog integrator. In this scheme the choice of time scales is somewhat restricted as each time step must be an exact multiple of the next smallest scale in the sequence. A novel generalisation of the nested leapfrog integrator is introduced which allows for far greater flexibility in the choice of time scales, as each scale now must only be an exact multiple of the smallest step size.

Kamleh, Waseem

2011-05-01

4

A Novel Multiple-Time Scale Integrator for the Hybrid Monte Carlo Algorithm  

SciTech Connect

Hybrid Monte Carlo simulations that implement the fermion action using multiple terms are commonly used. By the nature of their formulation they involve multiple integration time scales in the evolution of the system through simulation time. These different scales are usually dealt with by the Sexton-Weingarten nested leapfrog integrator. In this scheme the choice of time scales is somewhat restricted as each time step must be an exact multiple of the next smallest scale in the sequence. A novel generalisation of the nested leapfrog integrator is introduced which allows for far greater flexibility in the choice of time scales, as each scale now must only be an exact multiple of the smallest step size.

Kamleh, Waseem [Special Research Centre for the Subatomic Structure of Matter and Department of Physics, University of Adelaide 5005 (Australia)

2011-05-24

5

The Rational Hybrid Monte Carlo algorithm  

NASA Astrophysics Data System (ADS)

The past few years have seen considerable progress in algorithmic development for the generation of gauge fields including the effects of dynamical fermions. The Rational Hybrid Monte Carlo (RHMC) algorithm, where Hybrid Monte Carlo is performed using a rational approximation in place the usual inverse quark matrix kernel is one of these developments. This algorithm has been found to be extremely beneficial in many areas of lattice QCD (chiral fermions, finite temperature, Wilson fermions etc.). We review the algorithm and some of these benefits, and we compare against other recent algorithm developements. We conclude with an update of the Berlin wall plot comparing costs of all popular fermion formulations.

Clark, Michael

2006-12-01

6

A polynomial hybrid Monte Carlo algorithm  

NASA Astrophysics Data System (ADS)

We present a simulation algorithm for dynamical fermions that combines the multiboson technique with the hybrid Monte Carlo algorithm. We find that the algorithm gives a substantial gain over the standard methods in practical simulations. We point out the ability of the algorithm to treat fermion zero modes in a clean and controllable manner.

Frezzotti, Roberto; Jansen, Karl

1997-02-01

7

Hybrid silicon integration  

Microsoft Academic Search

An overview is presented of the hybrid AlGaInAs-silicon platform that enables wafer level integration of III-V optoelectronic\\u000a devices with silicon photonic devices based on silicon-on-insulator (SOI). Wafer bonding AlGaInAs quantum wells to an SOI\\u000a wafer allows large scale hybrid integration without any critical alignment steps. Discrete hybrid silicon optical amplifiers,\\u000a lasers and photodetectors are described, and the integration of a

R. Jones; H. D. Park; A. W. Fang; J. E. Bowers; O. Cohen; O. Raday; M. J. Paniccia

2009-01-01

8

Hybrid algorithms in quantum Monte Carlo  

SciTech Connect

With advances in algorithms and growing computing powers, quantum Monte Carlo (QMC) methods have become a leading contender for high accuracy calculations for the electronic structure of realistic systems. The performance gain on recent HPC systems is largely driven by increasing parallelism: the number of compute cores of a SMP and the number of SMPs have been going up, as the Top500 list attests. However, the available memory as well as the communication and memory bandwidth per element has not kept pace with the increasing parallelism. This severely limits the applicability of QMC and the problem size it can handle. OpenMP/MPI hybrid programming provides applications with simple but effective solutions to overcome efficiency and scalability bottlenecks on large-scale clusters based on multi/many-core SMPs. We discuss the design and implementation of hybrid methods in QMCPACK and analyze its performance on current HPC platforms characterized by various memory and communication hierarchies.

Esler, Kenneth P [ORNL; Mcminis, Jeremy [University of Illinois, Urbana-Champaign; Morales, Miguel A [Lawrence Livermore National Laboratory (LLNL); Clark, Bryan K. [Princeton University; Shulenburger, Luke [Sandia National Laboratory (SNL); Ceperley, David M [ORNL

2012-01-01

9

Hybrid optofluidic integration.  

PubMed

Complete integration of microfluidic and optical functions in a single lab-on-chip device is one goal of optofluidics. Here, we demonstrate the hybrid integration of a PDMS-based fluid handling layer with a silicon-based optical detection layer in a single optofluidic system. The optical layer consists of a liquid-core antiresonant reflecting optical waveguide (ARROW) chip that is capable of single particle detection and interfacing with optical fiber. Integrated devices are reconfigurable and able to sustain high pressures despite the small dimensions of the liquid-core waveguide channels. We show the combination of salient sample preparation capabilities-particle mixing, distribution, and filtering-with single particle fluorescence detection. Specifically, we demonstrate fluorescent labelling of ?-DNA, followed by flow-based single-molecule detection on a single device. This points the way towards amplification-free detection of nucleic acids with low-complexity biological sample preparation on a chip. PMID:23969694

Parks, Joshua W; Cai, Hong; Zempoaltecatl, Lynnell; Yuzvinsky, Thomas D; Leake, Kaelyn; Hawkins, Aaron R; Schmidt, Holger

2013-08-23

10

An integrated high-performance beam optics-nuclear processes framework with hybrid transfer map-Monte Carlo particle transport and optimization  

NASA Astrophysics Data System (ADS)

An integrated beam optics-nuclear processes framework is essential for accurate simulation of fragment separator beam dynamics. The code COSY INFINITY provides powerful differential algebraic methods for modeling and beam dynamics simulations in absence of beam-material interactions. However, these interactions are key for accurately simulating the dynamics of heavy ion fragmentation and fission. We have developed an extended version of the code that includes these interactions, and a set of new tools that allow efficient and accurate particle transport: by transfer map in vacuum and by Monte Carlo methods in materials. The new framework is presented, along with several examples from a preliminary layout of a fragment separator for a facility for rare isotope beams.

Bandura, L.; Erdelyi, B.; Nolen, J.

2010-12-01

11

A simplified variable metric hybrid Monte Carlo method  

NASA Astrophysics Data System (ADS)

We present a variable metric Hybrid Monte Carlo method following the ideas in [3], and propose a choice of such a metric which results efficient in the case of the sampling from the potential of a stiff spring. This is the first step in the extension of these ideas to deal with more general potentials appearing in Molecular Dynamics.

Calvo, M. P.; Rodrigo, I.; Sanz-Serna, J. M.

2013-10-01

12

Hybrid optoelectronic integrated circuit.  

PubMed

The distribution of optical signals to a monolithic array of GaAs photoconductors by means of ion-exchanged glass optical waveguides is demonstrated. In this hybrid technique both optical and electronic interconnections of semiconductor elements are achieved through the use of a metallic interconnect layer deposited on the surface of a glass substrate which has a mating waveguide pattern. The low optical loss, ease of fabrication, and low material cost of diffused glass waveguides with such layers permit relatively large optoelectronic circuit boards to be made, in which numerous semiconductor active optoelectronic devices can be included. The device reported here serves as the signal distribution and cross-point switching section of an optoelectronic switch matrix. PMID:20454231

Macdonald, R I; Lam, D K; Syrett, B A

1987-03-01

13

An integrated high-performance beam optics-nuclear processes framework with hybrid transfer map-Monte Carlo particle transport and optimization  

Microsoft Academic Search

An integrated beam optics-nuclear processes framework is essential for accurate simulation of fragment separator beam dynamics. The code COSY INFINITY provides powerful differential algebraic methods for modeling and beam dynamics simulations in absence of beam-material interactions. However, these interactions are key for accurately simulating the dynamics of heavy ion fragmentation and fission. We have developed an extended version of the

L. Bandura; B. Erdelyi; J. Nolend

2010-01-01

14

A hybrid Monte Carlo and response matrix Monte Carlo method in criticality calculation  

SciTech Connect

Full core calculations are very useful and important in reactor physics analysis, especially in computing the full core power distributions, optimizing the refueling strategies and analyzing the depletion of fuels. To reduce the computing time and accelerate the convergence, a method named Response Matrix Monte Carlo (RMMC) method based on analog Monte Carlo simulation was used to calculate the fixed source neutron transport problems in repeated structures. To make more accurate calculations, we put forward the RMMC method based on non-analog Monte Carlo simulation and investigate the way to use RMMC method in criticality calculations. Then a new hybrid RMMC and MC (RMMC+MC) method is put forward to solve the criticality problems with combined repeated and flexible geometries. This new RMMC+MC method, having the advantages of both MC method and RMMC method, can not only increase the efficiency of calculations, also simulate more complex geometries rather than repeated structures. Several 1-D numerical problems are constructed to test the new RMMC and RMMC+MC method. The results show that RMMC method and RMMC+MC method can efficiently reduce the computing time and variations in the calculations. Finally, the future research directions are mentioned and discussed at the end of this paper to make RMMC method and RMMC+MC method more powerful. (authors)

Li, Z.; Wang, K. [Dept. of Engineering Physics, Tsinghua Univ., Beijing, 100084 (China)

2012-07-01

15

Improved Monte Carlo Method for Evaluating Multidimensional Integrals.  

National Technical Information Service (NTIS)

The goal of this work was to develop an improved Monte Carlo method and implement a computer code for performing automatic integration of multidimensional integrals of the form integral f(X)dX over a closed region in k-dimensional Euclidean space, where X...

S. K. Yuen

1977-01-01

16

Markov chain Monte Carlo techniques in iterative detectors: a novel approach based on Monte Carlo integration  

Microsoft Academic Search

We present a novel soft-in soft-out (SISO) detection scheme based on Markov-chain Monte-Carlo (MCMC) simulations. The proposed detector is applicable to both synchronous multiuser and multiple-input multiple-output (MIMO) communication systems. Unlike previous publications on the subject, we use Monte Carlo integration technique to arrive at the receiver structure. The proposed multiuser\\/MIMO detector is found to follow the Rao-Blackwell formulation and

Zhenning Shi; Haidong Zhu; Behrouz Farhang-Boroujeny

2004-01-01

17

Independent Benchmarking of a Hybrid Monte Carlo Cross Section Code  

NASA Astrophysics Data System (ADS)

Understanding the effects of high-energy neutron interactions with certain materials is of considerable interest to the field of space radiation protection. Due to the expected radiation environment, neutron production and interactions with spacecraft materials will result in neutrons that can cause significant biological risk to crewmembers. For investigating incident particle interactions with target materials, an existing statistical model code (ALICE2008) was used for determining the particle spectra from a hybrid Monte Carlo simulation (HMS) of pre-compound nuclear decay. Presented is a comparison of neutron reaction cross-section results from ALICE2008 to reported values from widely accepted sources to benchmark the code for this specialized use with targets of interest.

Delauder, Nathan; Townsend, Lawrence

2011-10-01

18

Path Integral Quantum Monte Carlo Benchmarks for Molecules and Plasmas  

NASA Astrophysics Data System (ADS)

Path integral quantum Monte Carlo is used to simulate hot dense plasmas and other systems where quantum and thermal fluctuations are important. The fixed node approximation---ubiquitous in ab initio ground state Quantum Monte Carlo---is more complicated at finite temperatures, with many unanswered questions. In this talk I discuss the current state of fermionic path integral quantum Monte Carlo, with an emphasis on molecular systems where good benchmark data exists. We look at two ways of formulating the fixed node constraint and strategies for constructing finite-temperature nodal surfaces. We compare different the free energies of different nodal choices by sampling an ensemble of nodal models within a Monte Carlo simulation. We also present data on imaginary-time correlation fluctuations, which can be surprisingly accurate for molecular vibrations and polarizabilty.

Shumway, John

2013-03-01

19

2D hybrid meshes for direct simulation Monte Carlo solvers  

NASA Astrophysics Data System (ADS)

The efficiency of the direct simulation Monte Carlo (DSMC) method decreases considerably if gas is not rarefied. In order to extend the application range of the DSMC method towards non-rarefied gas regimes, the computational efficiency of the DSMC method should be increased further. One of the most time consuming parts of the DSMC method is to determine which DSMC molecules are in close proximity. If this information is calculated quickly, the efficiency of the DSMC method will be increased. Although some meshless methods are proposed, mostly structured or non-structured meshes are used to obtain this information. The simplest DSMC solvers are limited with the structured meshes. In these types of solvers, molecule indexing according to the positions can be handled very fast using simple arithmetic operations. But structured meshes are geometry dependent. Complicated geometries require the use of unstructured meshes. In this case, DSMC molecules are traced cell-by-cell. Different cell-by-cell tracing techniques exist. But, these techniques require complicated trigonometric operations or search algorithms. Both techniques are computationally expensive. In this study, a hybrid mesh structure is proposed. Hybrid meshes are both less dependent on the geometry like unstructured meshes and computationally efficient like structured meshes.

Sengil, N.; Sengil, U.

2013-02-01

20

ITER Neutronics Modeling Using Hybrid Monte Carlo/Deterministic and CAD-Based Monte Carlo Methods  

SciTech Connect

The immense size and complex geometry of the ITER experimental fusion reactor require the development of special techniques that can accurately and efficiently perform neutronics simulations with minimal human effort. This paper shows the effect of the hybrid Monte Carlo (MC)/deterministic techniques - Consistent Adjoint Driven Importance Sampling (CADIS) and Forward-Weighted CADIS (FW-CADIS) - in enhancing the efficiency of the neutronics modeling of ITER and demonstrates the applicability of coupling these methods with computer-aided-design-based MC. Three quantities were calculated in this analysis: the total nuclear heating in the inboard leg of the toroidal field coils (TFCs), the prompt dose outside the biological shield, and the total neutron and gamma fluxes over a mesh tally covering the entire reactor. The use of FW-CADIS in estimating the nuclear heating in the inboard TFCs resulted in a factor of ~ 275 increase in the MC figure of merit (FOM) compared with analog MC and a factor of ~ 9 compared with the traditional methods of variance reduction. By providing a factor of ~ 21 000 increase in the MC FOM, the radiation dose calculation showed how the CADIS method can be effectively used in the simulation of problems that are practically impossible using analog MC. The total flux calculation demonstrated the ability of FW-CADIS to simultaneously enhance the MC statistical precision throughout the entire ITER geometry. Collectively, these calculations demonstrate the ability of the hybrid techniques to accurately model very challenging shielding problems in reasonable execution times.

Ibrahim, A. [University of Wisconsin; Mosher, Scott W [ORNL; Evans, Thomas M [ORNL; Peplow, Douglas E. [ORNL; Sawan, M. [University of Wisconsin; Wilson, P. [University of Wisconsin; Wagner, John C [ORNL; Heltemes, Thad [University of Wisconsin, Madison

2011-01-01

21

Hybrid Monte Carlo-Deterministic Methods for Nuclear Reactor-Related Criticality Calculations  

SciTech Connect

The overall goal of this project is to develop, implement, and test new Hybrid Monte Carlo-deterministic (or simply Hybrid) methods for the more efficient and more accurate calculation of nuclear engineering criticality problems. These new methods will make use of two (philosophically and practically) very different techniques - the Monte Carlo technique, and the deterministic technique - which have been developed completely independently during the past 50 years. The concept of this proposal is to merge these two approaches and develop fundamentally new computational techniques that enhance the strengths of the individual Monte Carlo and deterministic approaches, while minimizing their weaknesses.

Edward W. Larson

2004-02-17

22

Hybrid S[sub N]/Monte Carlo research and results  

SciTech Connect

The neutral particle transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S[sub N]) and stochastic (Monte Carlo) methods are applied. The Monte Carlo and S[sub N] regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid Monte Carlo/S[sub N] method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S[sub N] is well suited for by themselves. The hybrid method has been successfully applied to realistic shielding problems. The vectorized Monte Carlo algorithm in the hybrid method has been ported to the massively parallel architecture of the Connection Machine. Comparisons of performance on a vector machine (Cray Y-MP) and the Connection Machine (CM-2) show that significant speedups are obtainable for vectorized Monte Carlo algorithms on massively parallel machines, even when realistic problems requiring variance reduction are considered. However, the architecture of the Connection Machine does place some limitations on the regime in which the Monte Carlo algorithm may be expected to perform well.

Baker, R.S.

1993-01-01

23

Hybrid S{sub N}/Monte Carlo research and results  

SciTech Connect

The neutral particle transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S{sub N}) and stochastic (Monte Carlo) methods are applied. The Monte Carlo and S{sub N} regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid Monte Carlo/S{sub N} method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S{sub N} is well suited for by themselves. The hybrid method has been successfully applied to realistic shielding problems. The vectorized Monte Carlo algorithm in the hybrid method has been ported to the massively parallel architecture of the Connection Machine. Comparisons of performance on a vector machine (Cray Y-MP) and the Connection Machine (CM-2) show that significant speedups are obtainable for vectorized Monte Carlo algorithms on massively parallel machines, even when realistic problems requiring variance reduction are considered. However, the architecture of the Connection Machine does place some limitations on the regime in which the Monte Carlo algorithm may be expected to perform well.

Baker, R.S.

1993-05-01

24

A hybrid device simulator that combines Monte Carlo and drift-diffusion analysis  

Microsoft Academic Search

A hybrid simulator suitable for modeling small semiconductor devices has been developed in which Monte Carlo and drift-diffusion models are combined. In critical device regions, the position-dependent coefficients of an extended drift-diffusion equation are extracted from a Monte Carlo simulation. Criteria for identifying these regions are described. Additional features which make the code more efficient are presented. First, a free-flight

Hans Kosina; Siegfried Selberherr

1994-01-01

25

Path Integral Monte Carlo Simulation of Hot, Dense Hydrogen  

NASA Astrophysics Data System (ADS)

Path integral Monte Carlo simulations have been applied to study the hot, dense hydrogen at Mega-bar pressures corresponding to the density and temperature range of 1 < rs < 14 and 5000 K < T < 1000000 K. We determine the equation of state and study the phase diagram including the molecular, atomic and plasma regime. We discuss the effects of different fermion nodes, which we improved by developing a variational thermal density matrix [1]. Furthermore, we calculate the deuterium Hugoniot [2] and compare with shock wave experiments. [1] B. Militzer, E.L. Pollock, ``Variational Density Matrix Method for Warm Condensed Matter and Application to Dense Hydrogen'', Phys. Rev. E 61 (2000) 3470. [2] B. Militzer, D. M. Ceperley, "Path Integral Monte Carlo Calculation of the Deuterium Hugoniot", Phys. Rev. Lett. 85 (2000) 1890.

Militzer, Burkhard

2001-03-01

26

The S/sub N//Monte Carlo response matrix hybrid method  

SciTech Connect

A hybrid method has been developed to iteratively couple S/sub N/ and Monte Carlo regions of the same problem. This technique avoids many of the restrictions and limitations of previous attempts to do the coupling and results in a general and relatively efficient method. We demonstrate the method with some simple examples.

Filippone, W.L.; Alcouffe, R.E.

1987-01-01

27

Hybrid manufacturing : integrating direct write and sterolithography.  

SciTech Connect

A commercial stereolithography (SL) machine was modified to integrate fluid dispensing or direct-write (DW) technology with SL in an integrated manufacturing environment for automated and efficient hybrid manufacturing of complex electrical devices, combining three-dimensional (3D) electrical circuitry with SL-manufactured parts. The modified SL system operates similarly to a commercially available machine, although build interrupts were used to stop and start the SL build while depositing fluid using the DW system. An additional linear encoder was attached to the SL platform z-stage and used to maintain accurate part registration during the SL and DW build processes. Individual STL files were required as part of the manufacturing process plan. The DW system employed a three-axis translation mechanism that was integrated with the commercial SL machine. Registration between the SL part, SL laser and the DW nozzle was maintained through the use of 0.025-inch diameter cylindrical reference holes manufactured in the part during SL. After depositing conductive ink using DW, the SL laser was commanded to trace the profile until the ink was cured. The current system allows for easy exchange between SL and DW in order to manufacture fully functional 3D electrical circuits and structures in a semi-automated environment. To demonstrate the manufacturing capabilities, the hybrid SL/DW setup was used to make a simple multi-layer SL part with embedded circuitry. This hybrid system is not intended to function as a commercial system, it is intended for experimental demonstration only. This hybrid SL/DW system has the potential for manufacturing fully functional electromechanical devices that are more compact, less expensive, and more reliable than their conventional predecessors, and work is ongoing in order to fully automate the current system.

Davis, Donald W.; Inamdar, Asim (University of Texas at El Paso, El Paso, TX); Lopes, Amit (University of Texas at El Paso, El Paso, TX); Chavez, Bart D.; Gallegos, Phillip L.; Palmer, Jeremy Andrew (University of Texas at El Paso, El Paso, TX); Wicker, Ryan B. (University of Texas at El Paso); Medina, Francisco (University of Texas at El Paso, El Paso, TX); Hennessey, Robert E. (University of Texas at El Paso, El Paso, TX)

2005-07-01

28

Hybrid Monte-Carlo method for simulating neutron and photon radiography  

NASA Astrophysics Data System (ADS)

We present a Hybrid Monte-Carlo method (HMCM) for simulating neutron and photon radiographs. HMCM utilizes the combination of a Monte-Carlo particle simulation for calculating incident film radiation and a statistical post-processing routine to simulate film noise. Since the method relies on MCNP for transport calculations, it is easily generalized to most non-destructive evaluation (NDE) simulations. We verify the method's accuracy through ASTM International's E592-99 publication, Standard Guide to Obtainable Equivalent Penetrameter Sensitivity for Radiography of Steel Plates [1]. Potential uses for the method include characterizing alternative radiological sources and simulating NDE radiographs.

Wang, Han; Tang, Vincent

2013-11-01

29

Novel Hybrid Monte Carlo/Deterministic Technique for Shutdown Dose Rate Analyses of Fusion Energy Systems  

SciTech Connect

The rigorous 2-step (R2S) method uses three-dimensional Monte Carlo transport simulations to calculate the shutdown dose rate (SDDR) in fusion reactors. Accurate full-scale R2S calculations are impractical in fusion reactors because they require calculating space- and energy-dependent neutron fluxes everywhere inside the reactor. The use of global Monte Carlo variance reduction techniques was suggested for accelerating the neutron transport calculation of the R2S method. The prohibitive computational costs of these approaches, which increase with the problem size and amount of shielding materials, inhibit their use in the accurate full-scale neutronics analyses of fusion reactors. This paper describes a novel hybrid Monte Carlo/deterministic technique that uses the Consistent Adjoint Driven Importance Sampling (CADIS) methodology but focuses on multi-step shielding calculations. The Multi-Step CADIS (MS-CADIS) method speeds up the Monte Carlo neutron calculation of the R2S method using an importance function that represents the importance of the neutrons to the final SDDR. Using a simplified example, preliminarily results showed that the use of MS-CADIS enhanced the efficiency of the neutron Monte Carlo simulation of an SDDR calculation by a factor of 550 compared to standard global variance reduction techniques, and that the increase over analog Monte Carlo is higher than 10,000.

Ibrahim, Ahmad M [ORNL; Peplow, Douglas E. [ORNL; Peterson, Joshua L [ORNL; Grove, Robert E [ORNL

2013-01-01

30

Defects in hybrid nematic films: a Monte Carlo Simulation  

NASA Astrophysics Data System (ADS)

Monte-Carlo simulations of a nematic liquid crystal film placed between two different media that set antagonistic (planar and homeotropic) orientation of the ``molecules" at the top and the bottom surfaces are presented. This system is a model of the HAND film [1] which, as observed in experimental studies, presents the formations of topological defects induced by the different alignement at the surface. Our simulation model is based on a Lebwohl-Lasher cubic lattice [2,3] where the molecules are represented by three dimensional unit vectors and interact only with their nearest neighbors. The lateral surface of the sample are left free, i.e. no boundary conditions are specified and it is found that the ground state of the system contains stable topological defects when the lateral radius of the system is larger than its thickness. [1] O.D. Lavrentovich and V.M. Pergamnschik, Int. J. Mod. Phys. B 9, 2839 (1995). [2] P.A. Lebwohl and G. Lasher, Phys. Rev. A 6 , 426 (1972). [3] U. Fabbri and C. Zannoni, Mol. Phys., 58, 763 (1986).

Pasini, P.; Chiccoli, C.; Lavrentovich, O. D.; Zannoni, C.

1997-08-01

31

RADIATION TRANSPORT THROUGH COMPLEX SHIELD PENETRATIONS IN ACCELERATOR ENVIRONMENTS USING HYBRID MONTE CARLO\\/DISCRETE ORDINATES CALCULATIONS  

Microsoft Academic Search

SUMMARY Shielding calculations for penetrations in the SNS accelerator environment are presented based on hybrid Monte Carlo and discrete ordinates particle transport methods. This methodology relies on coupling tools that map boundary surface leakage information from the Monte Carlo calculations to boundary sources for one-, two-, and three- dimensional discrete ordinates calculations. I. BACKGROUND Evaluating bulk shielding in accelerator environments

Franz X. Gallmeier

32

Review of Hybrid (Deterministic\\/Monte Carlo) Radiation Transport Methods, Codes, and Applications at Oak Ridge National Laboratory  

Microsoft Academic Search

This paper provides a review of the hybrid (Monte Carlo\\/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux,

John C Wagner; Douglas E. Peplow; Scott W Mosher; Thomas M Evans

2010-01-01

33

Review of Hybrid (Deterministic\\/Monte Carlo) Radiation Transport Methods, Codes, and Applications at Oak Ridge National Laboratory  

Microsoft Academic Search

This paper provides a review of the hybrid (Monte Carlo\\/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux,

John C Wagner; Douglas E. Peplow; Scott W Mosher; Thomas M Evans

2011-01-01

34

An improved Monte Carlo diffusion hybrid model for light reflectance by turbid media  

NASA Astrophysics Data System (ADS)

This paper introduces an improved diffusion model which is accurate and fast in computation for the cases of ?a/?’s < 0.07 as good as the conventional diffusion model for the cases of ?a/?’s < 0.007 for surface measurement, hence more suitable than the conventional model to be the forward model used in the image reconstruction in the diffuse optical tomography. Deviation of the diffusion approximation (DA) on the medium surface is first studied in the Monte Carlo (MC) diffusion hybrid model for reflectance setup. A modification of DA and an improved MC diffusion hybrid model based on this modified DA are introduced. Numerical tests show that for media with relatively strong absorption the present modified diffusion approach can reduce the surface deviation significantly in both the hybrid and pure diffusion model, and consumes nearly no more computation time than the conventional diffusion approach.

Luo, Bin; He, Sailing

2007-05-01

35

A Preliminary Study of In-House Monte Carlo Simulations: An Integrated Monte Carlo Verification System  

SciTech Connect

Purpose: To develop an infrastructure for the integrated Monte Carlo verification system (MCVS) to verify the accuracy of conventional dose calculations, which often fail to accurately predict dose distributions, mainly due to inhomogeneities in the patient's anatomy, for example, in lung and bone. Methods and Materials: The MCVS consists of the graphical user interface (GUI) based on a computational environment for radiotherapy research (CERR) with MATLAB language. The MCVS GUI acts as an interface between the MCVS and a commercial treatment planning system to import the treatment plan, create MC input files, and analyze MC output dose files. The MCVS consists of the EGSnrc MC codes, which include EGSnrc/BEAMnrc to simulate the treatment head and EGSnrc/DOSXYZnrc to calculate the dose distributions in the patient/phantom. In order to improve computation time without approximations, an in-house cluster system was constructed. Results: The phase-space data of a 6-MV photon beam from a Varian Clinac unit was developed and used to establish several benchmarks under homogeneous conditions. The MC results agreed with the ionization chamber measurements to within 1%. The MCVS GUI could import and display the radiotherapy treatment plan created by the MC method and various treatment planning systems, such as RTOG and DICOM-RT formats. Dose distributions could be analyzed by using dose profiles and dose volume histograms and compared on the same platform. With the cluster system, calculation time was improved in line with the increase in the number of central processing units (CPUs) at a computation efficiency of more than 98%. Conclusions: Development of the MCVS was successful for performing MC simulations and analyzing dose distributions.

Mukumoto, Nobutaka; Tsujii, Katsutomo; Saito, Susumu; Yasunaga, Masayoshi [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Takegawa, Hidek [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Higashinari-ku, Osaka (Japan); Yamamoto, Tokihiro; Numasaki, Hodaka [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Teshima, Teruki [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka (Japan)], E-mail: teshima@sahs.med.osaka-u.ac.jp

2009-10-01

36

Hybrid Integrity Solution for Precision Landing and Guidance.  

National Technical Information Service (NTIS)

NAVSYS Corporation has designed a hybrid integrity monitoring solution for precision approach and landing in a GPS environment degraded by RF interference. The integrity solution described in this paper leverages the capabilities of next generation digita...

K. L. Gold A. K. Brown

2004-01-01

37

A hybrid (Monte Carlo/deterministic) approach for multi-dimensional radiation transport  

SciTech Connect

Highlights: {yields} We introduce a variance reduction scheme for Monte Carlo (MC) transport. {yields} The primary application is atmospheric remote sensing. {yields} The technique first solves the adjoint problem using a deterministic solver. {yields} Next, the adjoint solution is used as an importance function for the MC solver. {yields} The adjoint problem is solved quickly since it ignores the volume. - Abstract: A novel hybrid Monte Carlo transport scheme is demonstrated in a scene with solar illumination, scattering and absorbing 2D atmosphere, a textured reflecting mountain, and a small detector located in the sky (mounted on a satellite or a airplane). It uses a deterministic approximation of an adjoint transport solution to reduce variance, computed quickly by ignoring atmospheric interactions. This allows significant variance and computational cost reductions when the atmospheric scattering and absorption coefficient are small. When combined with an atmospheric photon-redirection scheme, significant variance reduction (equivalently acceleration) is achieved in the presence of atmospheric interactions.

Bal, Guillaume, E-mail: gb2030@columbia.edu [Department of Applied Physics and Applied Mathematics, Columbia University, 200 S.W. Mudd Building, 500 W. 120th Street, New York, NY 10027 (United States); Davis, Anthony B., E-mail: Anthony.B.Davis@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-237, Pasadena, CA 91109 (United States); Kavli Institute for Theoretical Physics, Kohn Hall, University of California, Santa Barbara, CA 93106-4030 (United States); Langmore, Ian, E-mail: ianlangmore@gmail.com [Department of Applied Physics and Applied Mathematics, Columbia University, 200 S.W. Mudd Building, 500 W. 120th Street, New York, NY 10027 (United States)

2011-08-20

38

Hybrid Monte Carlo/Molecular Dynamics Simulation of a Refractory Metal High Entropy Alloy  

NASA Astrophysics Data System (ADS)

The high entropy alloy containing refractory metals Mo-Nb-Ta-W has a body-centered cubic structure, which is not surprising given the complete mutual solubility in BCC solid solutions of all pairs of the constituent elements. However, first principles total energy calculations for the binaries reveal a set of distinct energy minimizing structures implying the likelihood of chemically ordered low-temperature phases. We apply a hybrid Monte Carlo and molecular dynamics method to evaluate the temperature-dependent chemical order. Monte Carlo species swaps allow for equilibration of the structure that cannot be achieved by conventional molecular dynamics. At 300 K (27 °C), a cesium-chloride ordering emerges between mixed (Nb,Ta) sites and mixed (Mo,W) sites. This order is lost at elevated temperatures.

Widom, Michael; Huhn, W. P.; Maiti, S.; Steurer, W.

2013-10-01

39

Empirical Analysis of Stochastic Volatility Model by Hybrid Monte Carlo Algorithm  

NASA Astrophysics Data System (ADS)

The stochastic volatility model is one of volatility models which infer latent volatility of asset returns. The Bayesian inference of the stochastic volatility (SV) model is performed by the hybrid Monte Carlo (HMC) algorithm which is superior to other Markov Chain Monte Carlo methods in sampling volatility variables. We perform the HMC simulations of the SV model for two liquid stock returns traded on the Tokyo Stock Exchange and measure the volatilities of those stock returns. Then we calculate the accuracy of the volatility measurement using the realized volatility as a proxy of the true volatility and compare the SV model with the GARCH model which is one of other volatility models. Using the accuracy calculated with the realized volatility we find that empirically the SV model performs better than the GARCH model.

Takaishi, Tetsuya

2013-04-01

40

Rational hybrid Monte Carlo algorithm for theories with unknown spectral bounds  

SciTech Connect

The Rational Hybrid Monte Carlo (RHMC) algorithm extends the Hybrid Monte Carlo algorithm for lattice QCD simulations to situations involving fractional powers of the determinant of the quadratic Dirac operator. This avoids the updating increment (dt) dependence of observables which plagues the Hybrid Molecular-dynamics (HMD) method. The RHMC algorithm uses rational approximations to fractional powers of the quadratic Dirac operator. Such approximations are only available when positive upper and lower bounds to the operator's spectrum are known. We apply the RHMC algorithm to simulations of 2 theories for which a positive lower spectral bound is unknown: lattice QCD with staggered quarks at finite isospin chemical potential and lattice QCD with massless staggered quarks and chiral 4-fermion interactions ({chi}QCD). A choice of lower bound is made in each case, and the properties of the RHMC simulations these define are studied. Justification of our choices of lower bounds is made by comparing measurements with those from HMD simulations, and by comparing different choices of lower bounds.

Kogut, J. B.; Sinclair, D. K. [Department of Energy, Division of High Energy Physics, Washington, D.C. 20585 (United States) and Dept. of Physics-TQHN, Univ. of Maryland, 82 Regents Dr., College Park, Maryland 20742 (United States); HEP Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

2006-12-01

41

Rational hybrid Monte Carlo algorithm for theories with unknown spectral bounds.  

SciTech Connect

The Rational Hybrid Monte Carlo (RHMC) algorithm extends the Hybrid Monte Carlo algorithm for lattice QCD simulations to situations involving fractional powers of the determinant of the quadratic Dirac operator. This avoids the updating increment (dt) dependence of observables which plagues the Hybrid Molecular-dynamics (HMD) method. The RHMC algorithm uses rational approximations to fractional powers of the quadratic Dirac operator. Such approximations are only available when positive upper and lower bounds to the operator's spectrum are known. We apply the RHMC algorithm to simulations of 2 theories for which a positive lower spectral bound is unknown: lattice QCD with staggered quarks at finite isospin chemical potential and lattice QCD with massless staggered quarks and chiral 4-fermion interactions (chiQCD). A choice of lower bound is made in each case, and the properties of the RHMC simulations these define are studied. Justification of our choices of lower bounds is made by comparing measurements with those from HMD simulations, and by comparing different choices of lower bounds.

Sinclair, D. K.; Kogut, J. B.; High Energy Physics; Univ. of Maryland

2006-12-01

42

Hybrid two-dimensional Monte-Carlo electron transport in self-consistent electromagnetic fields  

SciTech Connect

The physics and numerics of the hybrid electron transport code ANTHEM are described. The need for the hybrid modeling of laser generated electron transport is outlined, and a general overview of the hybrid implementation in ANTHEM is provided. ANTHEM treats the background ions and electrons in a laser target as coupled fluid components moving relative to a fixed Eulerian mesh. The laser converts cold electrons to an additional hot electron component which evolves on the mesh as either a third coupled fluid or as a set of Monte Carlo PIC particles. The fluids and particles move in two-dimensions through electric and magnetic fields calculated via the Implicit Moment method. The hot electrons are coupled to the background thermal electrons by Coulomb drag, and both the hot and cold electrons undergo Rutherford scattering against the ion background. Subtleties of the implicit E- and B-field solutions, the coupled hydrodynamics, and large time step Monte Carlo particle scattering are discussed. Sample applications are presented.

Mason, R.J.; Cranfill, C.W.

1985-01-01

43

Monte Carlo integration to optimize geometry in gravitational experiments  

SciTech Connect

The torsion balance has been the experimental apparatus of choice for centuries, both in precision measurements of the Newtonian gravitational constant and in searches for weak anomalous interactions outside of gravity. If the form of the interaction is modeled, it is often possible to optimize the interacting bodies so that the apparatus has the greatest sensitivity to the interaction under study. Other researchers have applied this strategy in the case of the gravitational interaction between cylinders, and between a cylinder and sphere. Whereas their work focused on developing an analytical expression for the force between the masses, we present here a numerical method{minus}Monte Carlo integration{minus}which is general enough to aid in the design of bodies interacting under arbitrary potentials and with any desired geometric shape (as long as an accurate absolute value of the force is not needed). This numerical method is used to compute the gravitational torsion constant produced between an external hollow cylinder and sphere, and demonstrates the behavior studied previously through analysis. However, the main purpose for which we have used this numerical technique is in the design of interacting bodies used in a torsion-pendulum search for interactions that depend on net intrinsic spin. We demonstrate how the method may be used to determine the optimum aspect ratio ({ital l}/{ital r}) of the polarized test masses, as well as the most sensitive orientation of the masses. Two different interactions are considered: the dipole--dipole interaction between two polarized bodies, and the monopole--dipole interaction between a polarized and unpolarized body. In the case of the monopole--dipole interaction, we also show how the numerical method can indicate which orientation between test bodies is most susceptible to a false signal caused by gravity.

Winkler, L.I. (Division of Natural Sciences and Applied Mathematics, Stockton State College, Pomona, New Jersey 08240 (United States)); Goldblum, C.E. (R B Enterprises, 20 Clipper Road, West Conshohocken, Pennsylvania 19428-2721 (United States))

1992-07-01

44

Integrated electro-mechanical transmission systems in hybrid electric vehicles  

Microsoft Academic Search

Hybrid electric vehicles are emerging as a practical solution for meeting increasingly more stringent governmental standards for fuel economy and emissions. In order to improve performance, increase efficiency, and reduce costs, there is a trend toward more integrated electro-mechanical transmission systems for advanced hybrid powertrains. This paper primarily focuses on the state-of-the-art electro-mechanical integration of hybrid transmission systems and presents

Yinye Yang; Ali Emadi

2011-01-01

45

Integration of the Lippmann-Schwinger equation with the Monte Carlo method  

SciTech Connect

A Monte Carlo method to integrate the Lippmann-Schwinger equation for elastic scattering is presented. Advantages and limitations of this algorithm are compared with traditional methods of computation.

Salomon, M.

1983-12-01

46

Effect of nonlinearity in hybrid kinetic Monte Carlo-continuum models.  

PubMed

Recently there has been interest in developing efficient ways to model heterogeneous surface reactions with hybrid computational models that couple a kinetic Monte Carlo (KMC) model for a surface to a finite-difference model for bulk diffusion in a continuous domain. We consider two representative problems that validate a hybrid method and show that this method captures the combined effects of nonlinearity and stochasticity. We first validate a simple deposition-dissolution model with a linear rate showing that the KMC-continuum hybrid agrees with both a fully deterministic model and its analytical solution. We then study a deposition-dissolution model including competitive adsorption, which leads to a nonlinear rate, and show that in this case the KMC-continuum hybrid and fully deterministic simulations do not agree. However, we are able to identify the difference as a natural result of the stochasticity coming from the KMC surface process. Because KMC captures inherent fluctuations, we consider it to be more realistic than a purely deterministic model. Therefore, we consider the KMC-continuum hybrid to be more representative of a real system. PMID:22400701

Balter, Ariel; Lin, Guang; Tartakovsky, Alexandre M

2012-01-09

47

Classical mechanics on group manifolds and applications to hybrid Monte Carlo  

NASA Astrophysics Data System (ADS)

We formulate classical mechanics on a general group manifold, defining the natural symplectic structure as the 2-form ? ? -?id(pi?i), with p being the momentum and ? the left-invariant coframe. We verify that our formulation has the desired invariance properties and satisfies Lioville's theorem, and thus satisfies the conditions required for use in the hybrid Monte Carlo algorithm. We show that the equations of motion reduce to those previously hypothesized when written in terms of the constrained variables usually used to formulae lattice gauge theories, and discuss their discretization.

Kennedy, A. D.; Rossi, Pietro

1989-12-01

48

Worm algorithm and diagrammatic Monte Carlo: A new approach to continuous-space path integral Monte Carlo simulations  

Microsoft Academic Search

A detailed description is provided of a new worm algorithm, enabling the accurate computation of thermodynamic properties of quantum many-body systems in continuous space, at finite temperature. The algorithm is formulated within the general path integral Monte Carlo (PIMC) scheme, but also allows one to perform quantum simulations in the grand canonical ensemble, as well as to compute off-diagonal imaginary-time

M. Boninsegni; N. V. Prokof'Ev; B. V. Svistunov

2006-01-01

49

Integrated modeling and optimization of a parallel hydraulic hybrid bus  

Microsoft Academic Search

Hydraulic hybrid powertrains are a critical technology used in buses to improve fuel economy and emission performance. New\\u000a exploration in configuring a parallel hydraulic hybrid bus (PHHB) is developed in this paper with no changes made to the conventional\\u000a base bus driveline. An integrated model and simulation of the parallel hydraulic hybrid bus is built based on AMESim, which\\u000a is

Y. Yan; G. Liu; J. Chen

2010-01-01

50

Integrated Hybrid Lasers and Amplifiers on a Silicon Platform  

Microsoft Academic Search

An overview is given of the hybrid AlGaInAs-silicon platform where InP active and silicon passive components are integrated using wafer bonding. Hybrid optical amplifiers and lasers demonstrate the functionality this platform bring silicon photonics.

Richard Jones; Matthew N. Sysak; Alexander W. Fang; Hsu-Hao Chang; Ying Hao Kuo; John E. Bowers; Omri Raday; Oded Cohen

2008-01-01

51

Large-Scale Hybrid Integrated Circuitry: A Case Study  

Microsoft Academic Search

The continuing demand for greater circuit density has extended beyond the monolithic integrated circuit domain into the hybrid level,creating unique mechanical and thermal problems that exceed normal electrical concerns. The largest area consumer used in hybrid circuits is the filter capacitor chip. This chip, used fornoise suppression by decoupling from the power supply lines, is usually of a fairly large

H. Curnan; P. Bokalo

1987-01-01

52

Application study of a correction method for a spacecraft thermal model with a Monte-Carlo hybrid algorithm  

Microsoft Academic Search

The correction of a thermal model for a thermally controlled satellite in ground test conditions is studied using a Monte\\u000a Carlo hybrid algorithm. First, the global and local parameters are summarized according to sensitivity analyses on uncertain\\u000a parameters, and then the model correction is treated as a parameter optimization problem to be solved with a hybrid algorithm.\\u000a Finally, the correction

WenLong Cheng; Na Liu; Zhi Li; Qi Zhong; AiMing Wang; ZhiMin Zhang; ZongBo He

2011-01-01

53

Global Evaluation of Prompt Dose Rates in ITER Using Hybrid Monte Carlo/Deterministic Techniques  

SciTech Connect

The hybrid Monte Carlo (MC)/deterministic techniques - Consistent Adjoint Driven Importance Sampling (CADIS) and Forward Weighted CADIS (FW-CADIS) - enable the full 3-D modeling of very large and complicated geometries. The ability of performing global MC calculations for nuclear parameters throughout the entire ITER reactor was demonstrated. The 2 m biological shield (bioshield) reduces the total prompt operational dose by six orders of magnitude. The divertor cryo-pump port results in a peaking factor of 120 in the prompt operational dose rate behind the bioshield by a factor of 47. The peak values of the prompt dose rates at the back surface of the bioshield were 240 uSv/hr and 94 uSv/hr corresponding to the regions behind the divertor cryo-pump port and the equatorial port, respectively.

Ibrahim, A. [University of Wisconsin; Sawan, M. [University of Wisconsin; Mosher, Scott W [ORNL; Evans, Thomas M [ORNL; Peplow, Douglas E. [ORNL; Wilson, P. [University of Wisconsin; Wagner, John C [ORNL

2011-01-01

54

Business Scenario Evaluation Method Using Monte Carlo Simulation on Qualitative and Quantitative Hybrid Model  

NASA Astrophysics Data System (ADS)

We propose a business scenario evaluation method using qualitative and quantitative hybrid model. In order to evaluate business factors with qualitative causal relations, we introduce statistical values based on propagation and combination of effects of business factors by Monte Carlo simulation. In propagating an effect, we divide a range of each factor by landmarks and decide an effect to a destination node based on the divided ranges. In combining effects, we decide an effect of each arc using contribution degree and sum all effects. Through applied results to practical models, it is confirmed that there are no differences between results obtained by quantitative relations and results obtained by the proposed method at the risk rate of 5%.

Samejima, Masaki; Akiyoshi, Masanori; Mitsukuni, Koshichiro; Komoda, Norihisa

55

Hybrid and Parallel Domain-Decomposition Methods Development to Enable Monte Carlo for Reactor Analyses  

SciTech Connect

This paper describes code and methods development at the Oak Ridge National Laboratory focused on enabling high-fidelity, large-scale reactor analyses with Monte Carlo (MC). Current state-of-the-art tools and methods used to perform real commercial reactor analyses have several undesirable features, the most significant of which is the non-rigorous spatial decomposition scheme. Monte Carlo methods, which allow detailed and accurate modeling of the full geometry and are considered the gold standard for radiation transport solutions, are playing an ever-increasing role in correcting and/or verifying the deterministic, multi-level spatial decomposition methodology in current practice. However, the prohibitive computational requirements associated with obtaining fully converged, system-wide solutions restrict the role of MC to benchmarking deterministic results at a limited number of state-points for a limited number of relevant quantities. The goal of this research is to change this paradigm by enabling direct use of MC for full-core reactor analyses. The most significant of the many technical challenges that must be overcome are the slow, non-uniform convergence of system-wide MC estimates and the memory requirements associated with detailed solutions throughout a reactor (problems involving hundreds of millions of different material and tally regions due to fuel irradiation, temperature distributions, and the needs associated with multi-physics code coupling). To address these challenges, our research has focused on the development and implementation of (1) a novel hybrid deterministic/MC method for determining high-precision fluxes throughout the problem space in k-eigenvalue problems and (2) an efficient MC domain-decomposition (DD) algorithm that partitions the problem phase space onto multiple processors for massively parallel systems, with statistical uncertainty estimation. The hybrid method development is based on an extension of the FW-CADIS method, which attempts to achieve uniform statistical uncertainty throughout a designated problem space. The MC DD development is being implemented in conjunction with the Denovo deterministic radiation transport package to have direct access to the 3-D, massively parallel discrete-ordinates solver (to support the hybrid method) and the associated parallel routines and structure. This paper describes the hybrid method, its implementation, and initial testing results for a realistic 2-D quarter core pressurized-water reactor model and also describes the MC DD algorithm and its implementation.

Wagner, John C [ORNL; Mosher, Scott W [ORNL; Evans, Thomas M [ORNL; Peplow, Douglas E. [ORNL; Turner, John A [ORNL

2011-01-01

56

Automatic Mesh Adaptivity for Hybrid Monte Carlo/Deterministic Neutronics Modeling of Fusion Energy Systems  

SciTech Connect

Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.

Ibrahim, Ahmad M [ORNL; Wilson, P. [University of Wisconsin; Sawan, M. [University of Wisconsin; Mosher, Scott W [ORNL; Peplow, Douglas E. [ORNL; Grove, Robert E [ORNL

2013-01-01

57

The integration of improved Monte Carlo compton scattering algorithms into the Integrated TIGER Series.  

SciTech Connect

The Integrated TIGER Series (ITS) is a software package that solves coupled electron-photon transport problems. ITS performs analog photon tracking for energies between 1 keV and 1 GeV. Unlike its deterministic counterpart, the Monte Carlo calculations of ITS do not require a memory-intensive meshing of phase space; however, its solutions carry statistical variations. Reducing these variations is heavily dependent on runtime. Monte Carlo simulations must therefore be both physically accurate and computationally efficient. Compton scattering is the dominant photon interaction above 100 keV and below 5-10 MeV, with higher cutoffs occurring in lighter atoms. In its current model of Compton scattering, ITS corrects the differential Klein-Nishina cross sections (which assumes a stationary, free electron) with the incoherent scattering function, a function dependent on both the momentum transfer and the atomic number of the scattering medium. While this technique accounts for binding effects on the scattering angle, it excludes the Doppler broadening the Compton line undergoes because of the momentum distribution in each bound state. To correct for these effects, Ribbefor's relativistic impulse approximation (IA) will be employed to create scattering cross section differential in both energy and angle for each element. Using the parameterizations suggested by Brusa et al., scattered photon energies and angle can be accurately sampled at a high efficiency with minimal physical data. Two-body kinematics then dictates the electron's scattered direction and energy. Finally, the atomic ionization is relaxed via Auger emission or fluorescence. Future work will extend these improvements in incoherent scattering to compounds and to adjoint calculations.

Quirk, Thomas, J., IV (University of New Mexico)

2004-08-01

58

Monolithic and Hybrid Integrated ZB Converter Design  

NASA Astrophysics Data System (ADS)

In this study we have conducted two studies one in hybrid technology and the second one in monolithic technology. We have developed and processed two hybrid microwave converters @ 2.45 GHz. One for large signal applications and the other for small levels of power with 68% as RF-DC conversion efficiency for an input power of 20dBm.Afterwards, to test and validate the rectenna system we have optimised and achieved a 2x2 patch array which was associated to the both rectifiers processed. In order to minimize the RF- DC converter dimensions, we have optimised and developed a monolithic microwave zero bias rectifier @2.45GHz with an efficiency of 60% and 30dBm as a maximum input power using the ED02AH process derived from OMMIC.

Zbitou, J.; Latrach, M.; Toutain, S.

2004-12-01

59

Deposition of Colloidal Particles on Homogeneous Surfaces: Integral-Equation Theory and Monte Carlo Simulation  

Microsoft Academic Search

Deposition of large particles such as colloidal or bio-particles on a solid surface is usually modeled by the random sequential adsorption (RSA). The model was previously described by the integral-equation theory whose validity was proved by Monte Carlo simulation. This work generalized the model to include the concentration effect of added particles on the surface. The fraction of particles inserted

Panu Danwanichakul

2009-01-01

60

A quasi-Monte Carlo method for computing double and other multiple integrals  

Microsoft Academic Search

The heuristic importance of the Monte Carlo method lies in the fact that it shows the possibility of computing numerically integrals in many dimensions by taking averages of integrand values at a number of points in such a way that, for a given degree of accuracy, this number does not depend substantially on the number of dimensions of the domain

S. K. Zaremba

1970-01-01

61

Improvements to the Integrated TIGER Series Monte Carlo radiation transport codes  

Microsoft Academic Search

This paper describes two areas in which the usability of the Integrated TIGER Series (ITS) Monte Carlo radiation transport codes has been improved for use in the design and analysis of tests conducted with the DECADE nuclear weapons effects simulator. The first area is in improving the speed of execution. By benchmarking and profiling the member codes of the ITS

L. Montgomery Smith; Reuben D. Hochstedler

1997-01-01

62

Accelerating execution of the integrated TIGER series Monte Carlo radiation transport codes  

Microsoft Academic Search

Execution of the integrated TIGER series (ITS) of coupled electron\\/photon Monte Carlo radiation transport codes has been accelerated by modifying the FORTRAN source code for more efficient computation. Each member code of ITS was benchmarked and profiled with a specific test case that directed the acceleration effort toward the most computationally intensive subroutines. Techniques for accelerating these subroutines included replacing

L. Montgomery Smith; Reuben D. Hochstedler

1997-01-01

63

Path Integral Monte Carlo Simulations of Charged Particles in a Magnetic Field  

Microsoft Academic Search

The application of the path integral Monte Carlo (PIMC) method is discussed for the problem of charged particles in a static magnetic field. A major reason behind a lack of activity in this area has been a general pessimism regarding the statistical noise, which is expected to overwhelm the computation of thermal averages for moderately strong fields and low temperatures.

Sean Pearson

1997-01-01

64

Hybrid Monte Carlo-Diffusion Method For Light Propagation in Tissue With a Low-Scattering Region  

NASA Astrophysics Data System (ADS)

The heterogeneity of the tissues in a head, especially the low-scattering cerebrospinal fluid (CSF) layer surrounding the brain has previously been shown to strongly affect light propagation in the brain. The radiosity-diffusion method, in which the light propagation in the CSF layer is assumed to obey the radiosity theory, has been employed to predict the light propagation in head models. Although the CSF layer is assumed to be a nonscattering region in the radiosity-diffusion method, fine arachnoid trabeculae cause faint scattering in the CSF layer in real heads. A novel approach, the hybrid Monte Carlo-diffusion method, is proposed to calculate the head models, including the low-scattering region in which the light propagation does not obey neither the diffusion approximation nor the radiosity theory. The light propagation in the high-scattering region is calculated by means of the diffusion approximation solved by the finite-element method and that in the low-scattering region is predicted by the Monte Carlo method. The intensity and mean time of flight of the detected light for the head model with a low-scattering CSF layer calculated by the hybrid method agreed well with those by the Monte Carlo method, whereas the results calculated by means of the diffusion approximation included considerable error caused by the effect of the CSF layer. In the hybrid method, the time-consuming Monte Carlo calculation is employed only for the thin CSF layer, and hence, the computation time of the hybrid method is dramatically shorter than that of the Monte Carlo method.

Hayashi, Toshiyuki; Kashio, Yoshihiko; Okada, Eiji

2003-06-01

65

Hybrid Monte Carlo-diffusion method for light propagation in tissue with a low-scattering region.  

PubMed

The heterogeneity of the tissues in a head, especially the low-scattering cerebrospinal fluid (CSF) layer surrounding the brain has previously been shown to strongly affect light propagation in the brain. The radiosity-diffusion method, in which the light propagation in the CSF layer is assumed to obey the radiosity theory, has been employed to predict the light propagation in head models. Although the CSF layer is assumed to be a nonscattering region in the radiosity-diffusion method, fine arachnoid trabeculae cause faint scattering in the CSF layer in real heads. A novel approach, the hybrid Monte Carlo-diffusion method, is proposed to calculate the head models, including the low-scattering region in which the light propagation does not obey neither the diffusion approximation nor the radiosity theory. The light propagation in the high-scattering region is calculated by means of the diffusion approximation solved by the finite-element method and that in the low-scattering region is predicted by the Monte Carlo method. The intensity and mean time of flight of the detected light for the head model with a low-scattering CSF layer calculated by the hybrid method agreed well with those by the Monte Carlo method, whereas the results calculated by means of the diffusion approximation included considerable error caused by the effect of the CSF layer. In the hybrid method, the time-consuming Monte Carlo calculation is employed only for the thin CSF layer, and hence, the computation time of the hybrid method is dramatically shorter than that of the Monte Carlo method. PMID:12790437

Hayashi, Toshiyuki; Kashio, Yoshihiko; Okada, Eiji

2003-06-01

66

Wavelet-Monte Carlo Hybrid System for HLW Nuclide Migration Modeling and Sensitivity and Uncertainty Analysis  

SciTech Connect

This paper presents results of an uncertainty and sensitivity analysis for performance of the different barriers of high level radioactive waste repositories. SUA is a tool to perform the uncertainty and sensitivity on the output of Wavelet Integrated Repository System model (WIRS), which is developed to solve a system of nonlinear partial differential equations arising from the model formulation of radionuclide transport through repository. SUA performs sensitivity analysis (SA) and uncertainty analysis (UA) on a sample output from Monte Carlo simulation. The sample is generated by WIRS and contains the values of the output values of the maximum release rate in the form of time series and values of the input variables for a set of different simulations (runs), which are realized by varying the model input parameters. The Monte Carlo sample is generated with SUA as a pure random sample or using Latin Hypercube sampling technique. Tchebycheff and Kolmogrov confidence bounds are compute d on the maximum release rate for UA and effective non-parametric statistics to rank the influence of the model input parameters SA. Based on the results, we point out parameters that have primary influences on the performance of the engineered barrier system of a repository. The parameters found to be key contributor to the release rate are selenium and Cesium distribution coefficients in both geosphere and major water conducting fault (MWCF), the diffusion depth and water flow rate in the excavation-disturbed zone (EDZ).

Nasif, Hesham; Neyama, Atsushi

2003-02-26

67

Real-time hybrid simulation using the convolution integral method  

NASA Astrophysics Data System (ADS)

This paper proposes a real-time hybrid simulation method that will allow complex systems to be tested within the hybrid test framework by employing the convolution integral (CI) method. The proposed CI method is potentially transformative for real-time hybrid simulation. The CI method can allow real-time hybrid simulation to be conducted regardless of the size and complexity of the numerical model and for numerical stability to be ensured in the presence of high frequency responses in the simulation. This paper presents the general theory behind the proposed CI method and provides experimental verification of the proposed method by comparing the CI method to the current integration time-stepping (ITS) method. Real-time hybrid simulation is conducted in the Advanced Hazard Mitigation Laboratory at the University of Connecticut. A seismically excited two-story shear frame building with a magneto-rheological (MR) fluid damper is selected as the test structure to experimentally validate the proposed method. The building structure is numerically modeled and simulated, while the MR damper is physically tested. Real-time hybrid simulation using the proposed CI method is shown to provide accurate results.

Jig Kim, Sung; Christenson, Richard E.; Wojtkiewicz, Steven F.; Johnson, Erik A.

2011-02-01

68

Hybrid integrated silicon optical bench planar lightguide circuits  

Microsoft Academic Search

As optical system architectures have matured over the past ten years, the use of silicon optical bench (SiOB) technology for cost effective packaging of opto-electronic components has migrated from relatively simple laser and photodetector submounts to sophisticated hybrid integrated optical subsystems. Lucent Technologies Bell Laboratories has been developing SiOB technology for use as an integrated packaging platform for lasers, photodetectors,

J. Gates; D. Muehlner; M. Cappuzzo; M. Fishteyn; L. Gomez; G. Henein; E. Laskowski; I. Ryazansky; J. Shmulovich; D. Syvertsen; A. White

1998-01-01

69

Hybrid integrated lumped-element microwave amplifiers  

Microsoft Academic Search

This paper describes the development of microwave lumped-element thin-film amplifiers. The basic design philosophy underlying lumped inductors and capacitors at microwave frequencies is reviewed, showing how Q's of 100 are achieved. A variety of tunable input, output, and interstage integrated lumped-element networks for transistor amplifiers were fabricated. The gain and efficiency of 2-GHz class-C operated transistors mounted in these circuits

MARTIN CAULTON; STANLEY P. KNIGHT; DANIEL A. DALY

1968-01-01

70

Integrated oscillator/hybrid serves W-band radar applications  

NASA Astrophysics Data System (ADS)

A design of a compact two-channel monopulse W-band radar system is described, where a Gunn oscillator and short-slot hybrid are fabricated in an integrated structure via planar milling. The design, based on a radial-disk, bias post resonant circuit in a full-height waveguide, provides efficient impedance matching between the guide and the device.

Sarin, S. S.; Dixit, R. P.; Singh, Deepak

1991-12-01

71

Catalyzed growth of carbon nanotube with definable chirality by hybrid molecular dynamics-force biased Monte Carlo simulations.  

PubMed

Metal-catalyzed growth mechanisms of carbon nanotubes (CNTs) were studied by hybrid molecular dynamics-Monte Carlo simulations using a recently developed ReaxFF reactive force field. Using this novel approach, including relaxation effects, a CNT with definable chirality is obtained, and a step-by-step atomistic description of the nucleation process is presented. Both root and tip growth mechanisms are observed. The importance of the relaxation of the network is highlighted by the observed healing of defects. PMID:20939511

Neyts, Erik C; Shibuta, Yasushi; van Duin, Adri C T; Bogaerts, Annemie

2010-10-12

72

Hybrid quantum and classical mechanical Monte Carlo simulations of the interaction of hydrogen chloride with solid water clusters  

Microsoft Academic Search

Monte Carlo simulations using a hybrid quantum and classical mechanical potential were performed for crystal and amorphous-like HCl(H2O)n clusters (n?24). The subsystem composed by HCl and one water molecule was treated within density functional theory and a classical force field was used for the rest of the system. Simulations performed at 200 K suggest that the energetic feasibility of HCl

Dar??o A Estrin; Jorge Kohanoff; Daniel H. Laria; Ruben O. Weht

1997-01-01

73

HRMC_1.1: Hybrid Reverse Monte Carlo method with silicon and carbon potentials  

NASA Astrophysics Data System (ADS)

The Hybrid Reverse Monte Carlo (HRMC) code models the atomic structure of materials via the use of a combination of constraints including experimental diffraction data and an empirical energy potential. This energy constraint is in the form of either the Environment Dependent Interatomic Potential (EDIP) for carbon and silicon and the original and modified Stillinger-Weber potentials applicable to silicon. In this version, an update is made to correct an error in the EDIP carbon energy calculation routine.New version program summaryProgram title: HRMC version 1.1Catalogue identifier: AEAO_v1_1Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAO_v1_1.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 36?991No. of bytes in distributed program, including test data, etc.: 907?800Distribution format: tar.gzProgramming language: FORTRAN 77Computer: Any computer capable of running executables produced by the g77 Fortran compiler.Operating system: Unix, WindowsRAM: Depends on the type of empirical potential use, number of atoms and which constraints are employed.Classification: 7.7Catalogue identifier of previous version: AEAO_v1_0Journal reference of previous version: Comput. Phys. Comm. 178 (2008) 777Does the new version supersede the previous version?: YesNature of problem: Atomic modelling using empirical potentials and experimental data.Solution method: Monte CarloReasons for new version: An error in a term associated with the calculation of energies using the EDIP carbon potential which results in incorrect energies.Summary of revisions: Fix to correct brackets in the two body part of the EDIP carbon potential routine.Additional comments: The code is not standard FORTRAN 77 but includes some additional features and therefore generates errors when compiled using the Nag95 compiler. It does compile successfully with the GNU g77 compiler (http://www.gnu.org/software/fortran/fortran.html).Running time: Depends on the type of empirical potential use, number of atoms and which constraints are employed. The test included in the distribution took 37 minutes on a DEC Alpha PC.

Opletal, G.; Petersen, T. C.; O'Malley, B.; Snook, I. K.; McCulloch, D. G.; Yarovsky, I.

2011-02-01

74

All-electron path integral Monte Carlo simulations of warm dense matter: application to water and carbon plasmas.  

PubMed

We develop an all-electron path integral Monte Carlo method with free-particle nodes for warm dense matter and apply it to water and carbon plasmas. We thereby extend path integral Monte Carlo studies beyond hydrogen and helium to elements with core electrons. Path integral Monte Carlo results for pressures, internal energies, and pair-correlation functions compare well with density functional theory molecular dynamics calculations at temperatures of (2.5-7.5)×10(5) K, and both methods together form a coherent equation of state over a density-temperature range of 3-12 g/cm(3) and 10(4)-10(9) K. PMID:22540485

Driver, K P; Militzer, B

2012-03-16

75

Integration within the Felsenstein equation for improved Markov chain Monte Carlo methods in population genetics  

PubMed Central

In 1988, Felsenstein described a framework for assessing the likelihood of a genetic data set in which all of the possible genealogical histories of the data are considered, each in proportion to their probability. Although not analytically solvable, several approaches, including Markov chain Monte Carlo methods, have been developed to find approximate solutions. Here, we describe an approach in which Markov chain Monte Carlo simulations are used to integrate over the space of genealogies, whereas other parameters are integrated out analytically. The result is an approximation to the full joint posterior density of the model parameters. For many purposes, this function can be treated as a likelihood, thereby permitting likelihood-based analyses, including likelihood ratio tests of nested models. Several examples, including an application to the divergence of chimpanzee subspecies, are provided.

Hey, Jody; Nielsen, Rasmus

2007-01-01

76

General Hit-and-Run Monte Carlo sampling for evaluating multidimensional integrals  

Microsoft Academic Search

We elaborate on the Hit-and-Run sampler, a Monte Carlo approach that estimates the value of a high-dimensional integral with integrand h(x)f(x) by sampling from a time-reversible Markov chain over the suport of the density f. The Markov chain transitions are defined by choosing a random direction and then moving to a new point x whose likelihood depends on f in

Ming-Hui Chen; Bruce W. Schmeiser

1996-01-01

77

Monte Carlo integration in Glauber model analysis of reactions of halo nuclei  

Microsoft Academic Search

Reaction and elastic differential cross sections are calculated for light nuclei in the framework of the Glauber theory. The optical phase-shift function is evaluated by Monte Carlo integration. This enables us to use the most accurate wave functions and calculate the phase-shift functions without approximation. Examples of proton-nucleus (e.g., p-6He, p-6Li) and nucleus-nucleus (e.g.,6He-12C) scatterings illustrate the effectiveness of the

K. Varga; Steven C. Pieper; Y. Suzuki; R. B. Wiringa

2002-01-01

78

Integrating kinetic models for Simulating tumor growth in Monte Carlo Simulation of ECT systems  

Microsoft Academic Search

We have developed an integrated framework for linking tumor growth models directly into a Monte Carlo simulation algorithm for positron emission tomography and single-photon emission computed tomography systems. Tumors are approximated either by analytically defined five-dimensional (x,y,z,tgeometry,tactivity) compartments or by compound cellular lattice inserts. Both representation models can be placed into arbitrarily complex tomographic or mathematical phantoms. Various models for

Joerg Peter; Wolfhard Semmler

2004-01-01

79

A hybrid agent architecture integrating desire, intention and reinforcement learning  

Microsoft Academic Search

This paper presents a hybrid agent architecture that integrates the behaviours of BDI agents, specifically desire and intention, with a neural network based reinforcement learner known as Temporal Difference-Fusion Architecture for Learning and COgNition (TD-FALCON). With the explicit maintenance of goals, the agent performs reinforcement learning with the awareness of its objectives instead of relying on external reinforcement signals. More

Ah-Hwee Tan; Yew-Soon Ong; Akejariyawong Tapanuj

2011-01-01

80

Structural modelling of the LiCl aqueous solution by the hybrid reverse Monte Carlo (HRMC) simulation  

NASA Astrophysics Data System (ADS)

The reverse Monte Carlo (RMC) simulation is applied in the study of an aqueous electrolyte LiCl6H2O. On the basis of the available experimental neutron scattering data, RMC computes pair radial distribution functions in order to explore the structural features of the system. The obtained results include some unrealistic features. To overcome this problem, we use the hybrid reverse Monte Carlo (HRMC), incorporating an additional energy constraint in addition to the usual constraints of the pair correlation functions and average coordination. Our results show a good agreement between experimental and computed partial distribution functions (PDFs) as well as a significant improvement in pair partial distribution curves. This kind of study can be considered as a useful test for a defined interaction model for conventional simulation techniques

Habchi, M.; Mesli, S. M.; Kotbi, M.; Xu, H.

2012-08-01

81

Quantum Mechanical Single Molecule Partition Function from PathIntegral Monte Carlo Simulations  

SciTech Connect

An algorithm for calculating the partition function of a molecule with the path integral Monte Carlo method is presented. Staged thermodynamic perturbation with respect to a reference harmonic potential is utilized to evaluate the ratio of partition functions. Parallel tempering and a new Monte Carlo estimator for the ratio of partition functions are implemented here to achieve well converged simulations that give an accuracy of 0.04 kcal/mol in the reported free energies. The method is applied to various test systems, including a catalytic system composed of 18 atoms. Absolute free energies calculated by this method lead to corrections as large as 2.6 kcal/mol at 300 K for some of the examples presented.

Chempath, Shaji; Bell, Alexis T.; Predescu, Cristian

2006-10-01

82

Development of Integrated Motor Assist Hybrid System: Development of the 'Insight', a Personal Hybrid Coupe  

SciTech Connect

This paper presents the technical approach used to design and develop the powerplant for the Honda Insight, a new motor assist hybrid vehicle with an overall development objective of just half the fuel consumption of the current Civic over a wide range of driving conditions. Fuel consumption of 35km/L (Japanese 10-15 mode), and 3.4L/100km (98/69/EC) was realized. To achieve this, a new Integrated Motor Assist (IMA) hybrid power plant system was developed, incorporating many new technologies for packaging and integrating the motor assist system and for improving engine thermal efficiency. This was developed in combination with a new lightweight aluminum body with low aerodynamic resistance. Environmental performance goals also included the simultaneous achievement of low emissions (half the Japanese year 2000 standards, and half the EU2000 standards), high efficiency, and recyclability. Full consideration was also given to key consumer attributes, including crash safety performance, handling, and driving performance.

Kaoru Aoki; Shigetaka Kuroda; Shigemasa Kajiwara; Hiromitsu Sato; Yoshio Yamamoto

2000-06-19

83

Hybrid and Parallel Domain-Decomposition Methods Development to Enable Monte Carlo for Reactor Analyses  

Microsoft Academic Search

This paper describes code and methods development at the Oak Ridge National Laboratory focused on enabling high-fidelity, large-scale reactor analyses with Monte Carlo (MC). Current state-of-the-art tools and methods used to perform real commercial reactor analyses have several undesirable features, the most significant of which is the non-rigorous spatial decomposition scheme. Monte Carlo methods, which allow detailed and accurate modeling

John C Wagner; Scott W Mosher; Thomas M Evans; Douglas E. Peplow; John A Turner

2011-01-01

84

Hybrid and Parallel Domain-Decomposition Methods Development to Enable Monte Carlo for Reactor Analyses  

Microsoft Academic Search

This paper describes code and methods development at the Oak Ridge National Laboratory focused on enabling high-fidelity, large-scale reactor analyses with Monte Carlo (MC). Current state-of-the-art tools and methods used to perform ''real'' commercial reactor analyses have several undesirable features, the most significant of which is the non-rigorous spatial decomposition scheme. Monte Carlo methods, which allow detailed and accurate modeling

John C Wagner; Scott W Mosher; Thomas M Evans; Douglas E. Peplow; John A Turner

2010-01-01

85

Hybrid Description of Outflowing Ionospheric Plasma: A Monte Carlo\\/n-Moment Transport Equations Model  

Microsoft Academic Search

At terrestrial high latitudes, the plasma flows along ``open'' field lines, gradually going from a collision-dominated region into a collisionless region. Over several decades, the (fluid-like) generalized transport equations, TE, and the particle-based Monte Carlo, MC, approaches evolved as two of the most powerful simulation techniques that address this problem. In contrast to the computationally intensive Monte Carlo, the transport

J. Ji; A. R. Barakat; R. W. Schunk

2009-01-01

86

Spectroscopy and polarimetry capabilities of the INTEGRAL imager: Monte Carlo simulation results  

NASA Astrophysics Data System (ADS)

A three-dimensional position sensitive imaging detector has been proposed for the prospective ESA/NASA gamma-ray satellite, INTEGRAL. The instrument is based on two layers of bar shaped CsI(T1) crystals viewed by photodiodes. The GEANT3 Monte Carlo simulation package has been used to assess the spectroscopic and enhanced imaging performance of this detector and an original routine has been written to assess its capabilities as a Compton polarimeter. A description of the algorithm of this routine is given with the results of both GEANT3 and the polarization simulations.

Swinyard, Bruce M.; Malaguti, Giuseppe; Caroli, Ezio; Dean, Anthony J.; Di Cocco, Guido

1991-11-01

87

Monte Carlo Integration in Glauber Model Analysis of Reactions of Halo Nuclei  

Microsoft Academic Search

Reaction and elastic differential cross sections are calculated for light\\u000anuclei in the framework of the Glauber theory. The optical phase-shift function\\u000ais evaluated by Monte Carlo integration. This enables us to use the most\\u000aaccurate wave functions and calculate the phase-shift functions without\\u000aapproximation. Examples of proton nucleus (e.g. p-$^6$He, p-$^6$Li) and\\u000anucleus-nucleus (e.g. $^6$He$-^{12}$C) scatterings illustrate the effectiveness

Kalman Varga; Steven C. Pieper; Y. Suzuki; R. B. Wiringa

2002-01-01

88

Monte Carlo integration in Glauber model analysis of reactions of halo nuclei  

NASA Astrophysics Data System (ADS)

Reaction and elastic differential cross sections are calculated for light nuclei in the framework of the Glauber theory. The optical phase-shift function is evaluated by Monte Carlo integration. This enables us to use the most accurate wave functions and calculate the phase-shift functions without approximation. Examples of proton-nucleus (e.g., p-6He, p-6Li) and nucleus-nucleus (e.g.,6He-12C) scatterings illustrate the effectiveness of the method. This approach gives us a possibility of a more stringent analysis of the high-energy reactions of halo nuclei.

Varga, K.; Pieper, Steven C.; Suzuki, Y.; Wiringa, R. B.

2002-09-01

89

Data assimilation using a GPU accelerated path integral Monte Carlo approach  

NASA Astrophysics Data System (ADS)

The answers to data assimilation questions can be expressed as path integrals over all possible state and parameter histories. We show how these path integrals can be evaluated numerically using a Markov Chain Monte Carlo method designed to run in parallel on a graphics processing unit (GPU). We demonstrate the application of the method to an example with a transmembrane voltage time series of a simulated neuron as an input, and using a Hodgkin-Huxley neuron model. By taking advantage of GPU computing, we gain a parallel speedup factor of up to about 300, compared to an equivalent serial computation on a CPU, with performance increasing as the length of the observation time used for data assimilation increases.

Quinn, John C.; Abarbanel, Henry D. I.

2011-09-01

90

High Voltage Dielectrophoretic and Magnetophoretic Hybrid Integrated Circuit / Microfluidic Chip.  

PubMed

A hybrid integrated circuit (IC) / microfluidic chip is presented that independently and simultaneously traps and moves microscopic objects suspended in fluid using both electric and magnetic fields. This hybrid chip controls the location of dielectric objects, such as living cells and drops of fluid, on a 60 × 61 array of pixels that are 30 × 38 ?m(2) in size, each of which can be individually addressed with a 50 V peak-to-peak, DC to 10 MHz radio frequency voltage. These high voltage pixels produce electric fields above the chip's surface with a magnitude , resulting in strong dielectrophoresis (DEP) forces . Underneath the array of DEP pixels there is a magnetic matrix that consists of two perpendicular sets of 60 metal wires running across the chip. Each wire can be sourced with 120 mA to trap and move magnetically susceptible objects using magnetophoresis (MP). The DEP pixel array and magnetic matrix can be used simultaneously to apply forces to microscopic objects, such as living cells or lipid vesicles, that are tagged with magnetic nanoparticles. The capabilities of the hybrid IC / microfluidic chip demonstrated in this paper provide important building blocks for a platform for biological and chemical applications. PMID:20625468

Issadore, David; Franke, Thomas; Brown, Keith A; Hunt, Thomas P; Westervelt, Robert M

2009-12-01

91

High Voltage Dielectrophoretic and Magnetophoretic Hybrid Integrated Circuit / Microfluidic Chip  

PubMed Central

A hybrid integrated circuit (IC) / microfluidic chip is presented that independently and simultaneously traps and moves microscopic objects suspended in fluid using both electric and magnetic fields. This hybrid chip controls the location of dielectric objects, such as living cells and drops of fluid, on a 60 × 61 array of pixels that are 30 × 38 ?m2 in size, each of which can be individually addressed with a 50 V peak-to-peak, DC to 10 MHz radio frequency voltage. These high voltage pixels produce electric fields above the chip’s surface with a magnitude , resulting in strong dielectrophoresis (DEP) forces . Underneath the array of DEP pixels there is a magnetic matrix that consists of two perpendicular sets of 60 metal wires running across the chip. Each wire can be sourced with 120 mA to trap and move magnetically susceptible objects using magnetophoresis (MP). The DEP pixel array and magnetic matrix can be used simultaneously to apply forces to microscopic objects, such as living cells or lipid vesicles, that are tagged with magnetic nanoparticles. The capabilities of the hybrid IC / microfluidic chip demonstrated in this paper provide important building blocks for a platform for biological and chemical applications.

Issadore, David; Franke, Thomas; Brown, Keith A.; Hunt, Thomas P.; Westervelt, Robert M.

2010-01-01

92

Optical interconnection module integrated on a flexible optical\\/electrical hybrid printed circuit board  

Microsoft Academic Search

An optical interconnection module directly integrated on a flexible optical\\/electrical hybrid printed circuit board (O\\/E hybrid PCB) is presented. A newly proposed polymeric optical waveguide plays roles in the optical path and in a platform as an O\\/E hybrid PCB integrated with various optical\\/electrical components. The fabricated flexible O\\/E hybrid PCB had sufficient optical characteristics such as a low bending

Woo-Jin Lee; Sung Hwan Hwang; Jung Woon Lim; Che Hyun Cho; Gye Won Kim; Byung Sup Rho

2009-01-01

93

hybridMANTIS: a CPU-GPU Monte Carlo method for modeling indirect x-ray detectors with columnar scintillators.  

PubMed

The computational modeling of medical imaging systems often requires obtaining a large number of simulated images with low statistical uncertainty which translates into prohibitive computing times. We describe a novel hybrid approach for Monte Carlo simulations that maximizes utilization of CPUs and GPUs in modern workstations. We apply the method to the modeling of indirect x-ray detectors using a new and improved version of the code MANTIS, an open source software tool used for the Monte Carlo simulations of indirect x-ray imagers. We first describe a GPU implementation of the physics and geometry models in fastDETECT2 (the optical transport model) and a serial CPU version of the same code. We discuss its new features like on-the-fly column geometry and columnar crosstalk in relation to the MANTIS code, and point out areas where our model provides more flexibility for the modeling of realistic columnar structures in large area detectors. Second, we modify PENELOPE (the open source software package that handles the x-ray and electron transport in MANTIS) to allow direct output of location and energy deposited during x-ray and electron interactions occurring within the scintillator. This information is then handled by optical transport routines in fastDETECT2. A load balancer dynamically allocates optical transport showers to the GPU and CPU computing cores. Our hybridMANTIS approach achieves a significant speed-up factor of 627 when compared to MANTIS and of 35 when compared to the same code running only in a CPU instead of a GPU. Using hybridMANTIS, we successfully hide hours of optical transport time by running it in parallel with the x-ray and electron transport, thus shifting the computational bottleneck from optical tox-ray transport. The new code requires much less memory than MANTIS and, asa result, allows us to efficiently simulate large area detectors. PMID:22469917

Sharma, Diksha; Badal, Andreu; Badano, Aldo

2012-04-02

94

Novel Hybrid GPU-CPU Implementation of Parallelized Monte Carlo Parametric Expectation Maximization Estimation Method for Population Pharmacokinetic Data Analysis.  

PubMed

The development of a population PK/PD model, an essential component for model-based drug development, is both time- and labor-intensive. A graphical-processing unit (GPU) computing technology has been proposed and used to accelerate many scientific computations. The objective of this study was to develop a hybrid GPU-CPU implementation of parallelized Monte Carlo parametric expectation maximization (MCPEM) estimation algorithm for population PK data analysis. A hybrid GPU-CPU implementation of the MCPEM algorithm (MCPEMGPU) and identical algorithm that is designed for the single CPU (MCPEMCPU) were developed using MATLAB in a single computer equipped with dual Xeon 6-Core E5690 CPU and a NVIDIA Tesla C2070 GPU parallel computing card that contained 448 stream processors. Two different PK models with rich/sparse sampling design schemes were used to simulate population data in assessing the performance of MCPEMCPU and MCPEMGPU. Results were analyzed by comparing the parameter estimation and model computation times. Speedup factor was used to assess the relative benefit of parallelized MCPEMGPU over MCPEMCPU in shortening model computation time. The MCPEMGPU consistently achieved shorter computation time than the MCPEMCPU and can offer more than 48-fold speedup using a single GPU card. The novel hybrid GPU-CPU implementation of parallelized MCPEM algorithm developed in this study holds a great promise in serving as the core for the next-generation of modeling software for population PK/PD analysis. PMID:24002801

Ng, C M

2013-09-04

95

MASSCLEANCOLORS-MASS-DEPENDENT INTEGRATED COLORS FOR STELLAR CLUSTERS DERIVED FROM 30 MILLION MONTE CARLO SIMULATIONS  

SciTech Connect

We present Monte Carlo models of open stellar clusters with the purpose of mapping out the behavior of integrated colors with mass and age. Our cluster simulation package allows for stochastic variations in the stellar mass function to evaluate variations in integrated cluster properties. We find that UBVK colors from our simulations are consistent with simple stellar population (SSP) models, provided the cluster mass is large, M {sub cluster} {>=} 10{sup 6} M {sub sun}. Below this mass, our simulations show two significant effects. First, the mean value of the distribution of integrated colors moves away from the SSP predictions and is less red, in the first 10{sup 7} to 10{sup 8} years in UBV colors, and for all ages in (V - K). Second, the 1{sigma} dispersion of observed colors increases significantly with lower cluster mass. We attribute the former to the reduced number of red luminous stars in most of the lower mass clusters and the latter to the increased stochastic effect of a few of these stars on lower mass clusters. This latter point was always assumed to occur, but we now provide the first public code able to quantify this effect. We are completing a more extensive database of magnitudes and colors as a function of stellar cluster age and mass that will allow the determination of the correlation coefficients among different bands, and improve estimates of cluster age and mass from integrated photometry.

Popescu, Bogdan; Hanson, M. M. [Department of Physics, University of Cincinnati, P.O. Box 210011, Cincinnati, OH 45221-0011 (United States)], E-mail: popescb@mail.uc.edu, E-mail: margaret.hanson@uc.edu

2010-04-10

96

Better HMC integrators for dynamical simulations  

SciTech Connect

We show how to improve the molecular dynamics step of Hybrid Monte Carlo, both by tuning the integrator using Poisson brackets measurements and by the use of force gradient integrators. We present results for moderate lattice sizes.

M.A. Clark, Balint Joo, A.D. Kennedy, P.J. Silva

2010-06-01

97

Path integral Monte Carlo with importance sampling for excitons interacting with an arbitrary phonon bath  

NASA Astrophysics Data System (ADS)

The reduced density matrix of excitons coupled to a phonon bath at a finite temperature is studied using the path integral Monte Carlo method. Appropriate choices of estimators and importance sampling schemes are crucial to the performance of the Monte Carlo simulation. We show that by choosing the population-normalized estimator for the reduced density matrix, an efficient and physically-meaningful sampling function can be obtained. In addition, the nonadiabatic phonon probability density is obtained as a byproduct during the sampling procedure. For importance sampling, we adopted the Metropolis-adjusted Langevin algorithm. The analytic expression for the gradient of the target probability density function associated with the population-normalized estimator cannot be obtained in closed form without a matrix power series. An approximated gradient that can be efficiently calculated is explored to achieve better computational scaling and efficiency. Application to a simple one-dimensional model system from the previous literature confirms the correctness of the method developed in this manuscript. The displaced harmonic model system within the single exciton manifold shows the numerically exact temperature dependence of the coherence and population of the excitonic system. The sampling scheme can be applied to an arbitrary anharmonic environment, such as multichromophoric systems embedded in the protein complex. The result of this study is expected to stimulate further development of real time propagation methods that satisfy the detailed balance condition for exciton populations.

Shim, Sangwoo; Aspuru-Guzik, Alán

2012-12-01

98

An integrated Monte Carlo dosimetric verification system for radiotherapy treatment planning.  

PubMed

An integrated Monte Carlo (MC) dose calculation system, MCRTV (Monte Carlo for radiotherapy treatment plan verification), has been developed for clinical treatment plan verification, especially for routine quality assurance (QA) of intensity-modulated radiotherapy (IMRT) plans. The MCRTV system consists of the EGS4/PRESTA MC codes originally written for particle transport through the accelerator, the multileaf collimator (MLC), and the patient/phantom, which run on a 28-CPU Linux cluster, and the associated software developed for the clinical implementation. MCRTV has an interface with a commercial treatment planning system (TPS) (Eclipse, Varian Medical Systems, Palo Alto, CA, USA) and reads the information needed for MC computation transferred in DICOM-RT format. The key features of MCRTV have been presented in detail in this paper. The phase-space data of our 15 MV photon beam from a Varian Clinac 2300C/D have been developed and several benchmarks have been performed under homogeneous and several inhomogeneous conditions (including water, aluminium, lung and bone media). The MC results agreed with the ionization chamber measurements to within 1% and 2% for homogeneous and inhomogeneous conditions, respectively. The MC calculation for a clinical prostate IMRT treatment plan validated the implementation of the beams and the patient/phantom configuration in MCRTV. PMID:17374923

Yamamoto, T; Mizowaki, T; Miyabe, Y; Takegawa, H; Narita, Y; Yano, S; Nagata, Y; Teshima, T; Hiraoka, M

2007-03-20

99

A hybrid hydrodynamic-Monte Carlo simulation of the transport of neutral radicals in low-pressure remote plasma sources  

SciTech Connect

In low pressure electron cyclotron resonance and remote plasma enhanced chemical vapor deposition reactors (milliTorr to hundreds of milliTorr) the mean free path of excited state neutrals can be commensurate with the vessel dimensions. Deposition species may collide with the wall several times before encountering the substrate. While the movement of these particles is essentially ballistic, the advective flow of the background gas is a significant factor in the determination of the transport of the neutral radicals. To address these conditions, a hybrid hydrodynamic-Monte Carlo model has been developed. The advective flow field is calculated from the mass and momentum equations. Radical transport is then simulated using Monte Carlo techniques that include inelastic collisions with the background species and other MC particles, absorbing or reflective collisions with reactor surfaces, or momentum transfer with the advective fluid. Presented are the results describing the effects of geometry, pressure and gas flow for gas mixtures containing SiH[sub 4]. Identity, uniformity, and angle of incidence of the radical flux to the substrate will be addressed with the goal of optimizing the fluxes of selected species.

Hartig, M.J.

1993-01-01

100

a Hybrid Hydrodynamic-Monte Carlo Simulation of the Transport of Neutral Radicals in Low-Pressure Remote Plasma Sources.  

NASA Astrophysics Data System (ADS)

In low pressure electron cyclotron resonance and remote plasma enhanced chemical vapor deposition reactors (milliTorr to hundreds of milliTorr) the mean free path of excited state neutrals can be commensurate with the vessel dimensions. Deposition species may collide with the wall several times before encountering the substrate. While the movement of these particles is essentially ballistic, the advective flow of the background gas is a significant factor in the determination of the transport of the neutral radicals. To address these conditions, a hybrid hydrodynamic -Monte Carlo model has been developed. The advective flow field is calculated from the mass and momentum equations. Radical transport is then simulated using Monte Carlo techniques that include inelastic collisions with the background species and other MC particles, absorbing or reflective collisions with reactor surfaces, or momentum transfer with the advective fluid. Presented here are the results describing the effects of geometry, pressure and gas flow for gas mixtures containing SiH_4. Identity, uniformity, and angle of incidence of the radical flux to the substrate will be addressed with the goal of optimizing the fluxes of selected species.

Hartig, Michael Joseph

101

Accelerating execution of the integrated TIGER series Monte Carlo radiation transport codes  

SciTech Connect

Execution of the integrated TIGER series (ITS) of coupled electron/photon Monte Carlo radiation transport codes has been accelerated by modifying the FORTRAN source code for more efficient computation. Each member code of ITS was benchmarked and profiled with a specific test case that directed the acceleration effort toward the most computationally intensive subroutines. Techniques for accelerating these subroutines included replacing linear search algorithms with binary versions, replacing the pseudo-random number generator, reducing program memory allocation, and proofing the input files for geometrical redundancies. All techniques produced identical or statistically similar results to the original code. Final benchmark timing of the accelerated code resulted in speed-up factors of 2.00 for TIGER (the one-dimensional slab geometry code), 1.74 for CYLTRAN (the two-dimensional cylindrical geometry code), and 1.90 for ACCEPT (the arbitrary three-dimensional geometry code).

Smith, L.M.; Hochstedler, R.D. [Univ of Tennessee Space Inst., Tullahoma, TN (United States). Dept. of Electrical Engineering

1997-02-01

102

Combined Monte Carlo narrow resonance - intermediate resonance method for testing resonance integral calculations in complex geometries  

SciTech Connect

The narrow resonance (NR) approximation has, in the past, been applied to regular lattices with fairly simple unit cells. Attempts to use the NR approximation to deal with fine details of the lattice structure, or with complicated lattice cells, have generally been based on assumptions and approximations that are rather difficult to evaluate. A benchmark method is developed in which slowing down is still treated in the NR approximation, but spatial neutron transport is handled by Monte Carlo. This benchmark method is used to evaluate older methods for analyzing the double-heterogeneity effect in fast reactors, and for computing resonance integrals in the PROTEUS lattices. New methods for treating the PROTEUS lattices are proposed.

Chen, I.J.; Gelbard, E.M.

1988-07-01

103

Dynamical structure functions from quantum Monte Carlo calculations of a proper integral transform  

NASA Astrophysics Data System (ADS)

An ab initio method for determining the dynamical structure function of an interacting many-body quantum system has been devised by combining a generalized integral transform method with quantum Monte Carlo (QMC) methods. A kernel has been found that (i) lets the transform be calculable with QMC methods and (ii) is a representation of the ? function, allowing an inversion of the transform with a much higher predictive power than the inverse Laplace transform. As a first application, the excitation spectrum of bulk atomic 4He has been computed, both in the low and intermediate momentum ranges. The peculiar form of the kernel allows us to predict, without using any model, both positions and widths of the collective excitations in the maxon-roton region, as well as the existence of the second collective peak. A prediction of the dispersion of the single-particle modes described by the incoherent part is also presented.

Roggero, Alessandro; Pederiva, Francesco; Orlandini, Giuseppina

2013-09-01

104

WORM ALGORITHM PATH INTEGRAL MONTE CARLO APPLIED TO THE 3He-4He II SANDWICH SYSTEM  

NASA Astrophysics Data System (ADS)

We present a numerical investigation of the thermal and structural properties of the 3He-4He sandwich system adsorbed on a graphite substrate using the worm algorithm path integral Monte Carlo (WAPIMC) method [M. Boninsegni, N. Prokof'ev and B. Svistunov, Phys. Rev. E74, 036701 (2006)]. For this purpose, we have modified a previously written WAPIMC code originally adapted for 4He on graphite, by including the second 3He-component. To describe the fermions, a temperature-dependent statistical potential has been used. This has proven very effective. The WAPIMC calculations have been conducted in the millikelvin temperature regime. However, because of the heavy computations involved, only 30, 40 and 50 mK have been considered for the time being. The pair correlations, Matsubara Green's function, structure factor, and density profiles have been explored at these temperatures.

Al-Oqali, Amer; Sakhel, Asaad R.; Ghassib, Humam B.; Sakhel, Roger R.

2012-12-01

105

Finite Size Effect in Path Integral Monte Carlo Simulations of 4 He Systems  

NASA Astrophysics Data System (ADS)

Path integral Monte Carlo (PIMC) simulations are a powerful computational method to study interacting quantum systems at finite temperatures. In this work, PIMC has been applied to study the finite size effect of the simulated systems of 4 He. We determine the energy as a function of temperature at saturated-vapor-pressure (SVP) conditions in the temperature range of T ? [1.0 K,4.0 K], and the equation of state (EOS) in the ground state for systems consisted of 32, 64 and 128 4 He atoms, respectively. We find that the energy at SVP is influenced significantly by the size of the simulated system in the temperature range of T ? [2.1 K, 3.0 K] and the larger the system is, the better results are obtained in comparison with the experimental values; while the EOS appeared to be unrelated to it.

Zhao, Xing-Wen; Cheng, Xin-Lu

2008-10-01

106

Memristor-CMOS hybrid integrated circuits for reconfigurable logic.  

PubMed

Hybrid reconfigurable logic circuits were fabricated by integrating memristor-based crossbars onto a foundry-built CMOS (complementary metal-oxide-semiconductor) platform using nanoimprint lithography, as well as materials and processes that were compatible with the CMOS. Titanium dioxide thin-film memristors served as the configuration bits and switches in a data routing network and were connected to gate-level CMOS components that acted as logic elements, in a manner similar to a field programmable gate array. We analyzed the chips using a purpose-built testing system, and demonstrated the ability to configure individual devices, use them to wire up various logic gates and a flip-flop, and then reconfigure devices. PMID:19722537

Xia, Qiangfei; Robinett, Warren; Cumbie, Michael W; Banerjee, Neel; Cardinali, Thomas J; Yang, J Joshua; Wu, Wei; Li, Xuema; Tong, William M; Strukov, Dmitri B; Snider, Gregory S; Medeiros-Ribeiro, Gilberto; Williams, R Stanley

2009-10-01

107

Review of Hybrid (Deterministic/Monte Carlo) Radiation Transport Methods, Codes, and Applications at Oak Ridge National Laboratory  

SciTech Connect

This paper provides a review of the hybrid (Monte Carlo/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux, dose, or reaction rate at a particular location) and (2) Forward Weighted CADIS (FW-CADIS) for optimizing distributions (e.g., mesh tallies over all or part of the problem space) or multiple localized detector regions (e.g., simultaneous optimization of two or more localized tally regions). The two methods have been implemented and automated in both the MAVRIC sequence of SCALE 6 and ADVANTG, a code that works with the MCNP code. As implemented, the methods utilize the results of approximate, fast-running 3-D discrete ordinates transport calculations (with the Denovo code) to generate consistent space- and energy-dependent source and transport (weight windows) biasing parameters. These methods and codes have been applied to many relevant and challenging problems, including calculations of PWR ex-core thermal detector response, dose rates throughout an entire PWR facility, site boundary dose from arrays of commercial spent fuel storage casks, radiation fields for criticality accident alarm system placement, and detector response for special nuclear material detection scenarios and nuclear well-logging tools. Substantial computational speed-ups, generally O(10{sup 2-4}), have been realized for all applications to date. This paper provides a brief review of the methods, their implementation, results of their application, and current development activities, as well as a considerable list of references for readers seeking more information about the methods and/or their applications.

Wagner, John C [ORNL; Peplow, Douglas E. [ORNL; Mosher, Scott W [ORNL; Evans, Thomas M [ORNL

2010-01-01

108

Review of Hybrid (Deterministic/Monte Carlo) Radiation Transport Methods, Codes, and Applications at Oak Ridge National Laboratory  

SciTech Connect

This paper provides a review of the hybrid (Monte Carlo/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux, dose, or reaction rate at a particular location) and (2) Forward Weighted CADIS (FW-CADIS) for optimizing distributions (e.g., mesh tallies over all or part of the problem space) or multiple localized detector regions (e.g., simultaneous optimization of two or more localized tally regions). The two methods have been implemented and automated in both the MAVRIC sequence of SCALE 6 and ADVANTG, a code that works with the MCNP code. As implemented, the methods utilize the results of approximate, fast-running 3-D discrete ordinates transport calculations (with the Denovo code) to generate consistent space- and energy-dependent source and transport (weight windows) biasing parameters. These methods and codes have been applied to many relevant and challenging problems, including calculations of PWR ex-core thermal detector response, dose rates throughout an entire PWR facility, site boundary dose from arrays of commercial spent fuel storage casks, radiation fields for criticality accident alarm system placement, and detector response for special nuclear material detection scenarios and nuclear well-logging tools. Substantial computational speed-ups, generally O(102-4), have been realized for all applications to date. This paper provides a brief review of the methods, their implementation, results of their application, and current development activities, as well as a considerable list of references for readers seeking more information about the methods and/or their applications.

Wagner, John C [ORNL; Peplow, Douglas E. [ORNL; Mosher, Scott W [ORNL; Evans, Thomas M [ORNL

2011-01-01

109

Integration of Converter Losses in the Modelling of Hybrid Photovoltaic-Wind Generating System  

Microsoft Academic Search

Basic hybrid system has become a focal point in the research of renewable energy sources. This paper provides an energy based model of stand-alone hybrid renewable electrical systems using bond graph approach. An equivalent average model of a hybrid wind-photovoltaic generating system is proposed. The modelling of the components of the global system is developed with the integration of converters

Fatma Soltani; Noureddine Debbache

2008-01-01

110

Hybrid automata of an integrated motor-transmission powertrain for automatic gear shift  

Microsoft Academic Search

This paper presents a scheme of hybrid modeling of an integrated motor-transmission powertrain, which is increasingly applied to electric vehicles. The shift process of this system is special due to the absence of clutch, and the mode switch of the propulsion motor increases hybrid characteristics. After the introduction of a definition of hybrid automaton and the analysis of shift process,

Hong Fu; Guangyu Tian; Quanshi Chen; Yiding Jin

2011-01-01

111

Extension of the Integrated Tiger Series (ITS) of electron-photon Monte Carlo codes to 100 GeV  

SciTech Connect

Version 2.1 of the Integrated Tiger Series (ITS) of electron-photon Monte Carlo codes was modified to extend their ability to model interactions up to 100 GeV. Benchmarks against experimental results conducted at 10 and 15 GeV confirm the accuracy of the extended codes. 12 refs., 2 figs., 2 tabs.

Miller, S.G.

1989-10-01

112

Extension of the Integrated Tiger Series (ITS) of electron-photon Monte Carlo codes to 100 GeV  

SciTech Connect

Version 2.1 of the Integrated Tiger Series (ITS) of electron-photon Monte Carlo codes was modified to extend their ability to model interactions up to 100 GeV. Benchmarks against experimental results conducted at 10 and 15 GeV confirm the accuracy of the extended codes. 12 refs., 2 figs., 2 tabs.

Miller, S.G.

1988-08-01

113

Variational upper and lower bounds on quantum free energy and energy differences via path integral Monte Carlo  

SciTech Connect

A newly developed variational method for obtaining upper and lower bounds on free energy changes is extended to quantum systems. The convergence of the upper and lower bounds is demonstrated for simple test cases in one and three dimensions, using various path integral Monte Carlo methods, including the bead'' method, the Fourier component method, and multigrid techniques.

Hogenson, G.J.; Reinhardt, W.P. (Department of Chemistry BG-10, University of Washington, Seattle, Washington 98195 (United States))

1995-03-08

114

Monte Carlo simulation of small electron fields collimated by the integrated photon MLC  

NASA Astrophysics Data System (ADS)

In this study, a Monte Carlo (MC)-based beam model for an ELEKTA linear accelerator was established. The beam model is based on the EGSnrc Monte Carlo code, whereby electron beams with nominal energies of 10, 12 and 15 MeV were considered. For collimation of the electron beam, only the integrated photon multi-leaf-collimators (MLCs) were used. No additional secondary or tertiary add-ons like applicators, cutouts or dedicated electron MLCs were included. The source parameters of the initial electron beam were derived semi-automatically from measurements of depth-dose curves and lateral profiles in a water phantom. A routine to determine the initial electron energy spectra was developed which fits a Gaussian spectrum to the most prominent features of depth-dose curves. The comparisons of calculated and measured depth-dose curves demonstrated agreement within 1%/1 mm. The source divergence angle of initial electrons was fitted to lateral dose profiles beyond the range of electrons, where the imparted dose is mainly due to bremsstrahlung produced in the scattering foils. For accurate modelling of narrow beam segments, the influence of air density on dose calculation was studied. The air density for simulations was adjusted to local values (433 m above sea level) and compared with the standard air supplied by the ICRU data set. The results indicate that the air density is an influential parameter for dose calculations. Furthermore, the default value of the BEAMnrc parameter 'skin depth' for the boundary crossing algorithm was found to be inadequate for the modelling of small electron fields. A higher value for this parameter eliminated discrepancies in too broad dose profiles and an increased dose along the central axis. The beam model was validated with measurements, whereby an agreement mostly within 3%/3 mm was found.

Mihaljevic, Josip; Soukup, Martin; Dohm, Oliver; Alber, Markus

2011-02-01

115

Dynamical estimation of neuron and network properties II: Path integral Monte Carlo methods.  

PubMed

Hodgkin-Huxley (HH) models of neuronal membrane dynamics consist of a set of nonlinear differential equations that describe the time-varying conductance of various ion channels. Using observations of voltage alone we show how to estimate the unknown parameters and unobserved state variables of an HH model in the expected circumstance that the measurements are noisy, the model has errors, and the state of the neuron is not known when observations commence. The joint probability distribution of the observed membrane voltage and the unobserved state variables and parameters of these models is a path integral through the model state space. The solution to this integral allows estimation of the parameters and thus a characterization of many biological properties of interest, including channel complement and density, that give rise to a neuron's electrophysiological behavior. This paper describes a method for directly evaluating the path integral using a Monte Carlo numerical approach. This provides estimates not only of the expected values of model parameters but also of their posterior uncertainty. Using test data simulated from neuronal models comprising several common channels, we show that short (<50 ms) intracellular recordings from neurons stimulated with a complex time-varying current yield accurate and precise estimates of the model parameters as well as accurate predictions of the future behavior of the neuron. We also show that this method is robust to errors in model specification, supporting model development for biological preparations in which the channel expression and other biophysical properties of the neurons are not fully known. PMID:22526358

Kostuk, Mark; Toth, Bryan A; Meliza, C Daniel; Margoliash, Daniel; Abarbanel, Henry D I

2012-04-13

116

Design of a hybrid-integrated MEMS scanning grating spectrometer  

NASA Astrophysics Data System (ADS)

Optical MEMS (micro electro mechanical systems) have been used to reduce size, weight and costs of any kind of optical systems very successfully starting in the last decades. Scientists at Fraunhofer IPMS invented a resonant drive for 1-d and 2-d MEMS scanning mirror devices. Besides mirrors also scanning gratings have been realized. Now, rapidly growing new applications demand for enhanced functions and further miniaturization. This task cannot be solved by simply putting more functionality into the MEMS chip, for example grating and slit structures, but by three dimensional hybrid integration of the complete optical system into a stack of several functional substrates. Here we present the optical system design and realization strategy for a scanning grating spectrometer for the near infrared (NIR) range. First samples will be mounted from single components by a bonder tool (Finetech Fineplacer Femto) but the option of wafer assembly will be kept open for future developments. Extremely miniaturized NIR spectrometer could serve a wide variety of applications for handheld devices from food quality analysis to medical services or materials identification.

Pügner, Tino; Knobbe, Jens; Grüger, Heinrich; Schenk, Harald

2011-09-01

117

Platform technologies for hybrid optoelectronic integration and packaging  

NASA Astrophysics Data System (ADS)

In order to bring fiber-optics closer to individual home and business services, the optical network components have to be inexpensive and reliable. Integration and packaging of optoelectronic devices holds the key to high-volume low-cost component manufacturing. The goal of this dissertation is to propose, study, and demonstrate various ways to integrate optoelectronic devices on a packaging platform to implement cost-effective, functional optical modules. Two types of hybrid integration techniques have been proposed: flip-chip solder bump bonding for high-density two-dimensional array packaging of surface-emitting devices, and solder preform bonding for fiber-coupled edge-emitting semiconductor devices. For flip-chip solder bump bonding, we developed a simple, inexpensive remetallization process called "electroless plating", which converts the aluminum bond pads of foundry-made complementary metal oxide semiconductor (CMOS) chips into solder-bondable and wire-bondable gold surfaces. We have applied for a patent on this remetallization technique. For fiber-pigtailed edge-emitting laser modules, we have studied the coupling characteristics of different types of lensed single-mode fibers including semispherically lensed fiber, cylindrically lensed fiber and conically lensed fiber. We have experimentally demonstrated 66% coupling efficiency with semispherically lensed fiber and 50% efficiency with conically lensed fibers. We have proposed and designed a packaging platform on which lensed fibers can be actively aligned to a laser and solder-attached reliably to the platform so that the alignment is retained. We have designed thin-film nichrome heaters on fused quartz platforms as local heat source to facilitate on-board solder alignment and attachment of fiber. The thermal performance of the heaters was simulated using finite element analysis tool ANSYS prior to fabrication. Using the heater's reworkability advantage, we have estimated the shift of the fiber due to solder shrinkage and introduced a pre-correction in the alignment process to restore optimum coupling efficiency close to 50% with conically lensed fibers. We have applied for a patent on this unique active alignment method through the University of Maryland's Technology Commercialization Office. Although we have mostly concentrated on active alignment platforms, we have proposed the idea of combining the passive alignment advantages of silicon optical benches to the on-board heater-assisted active alignment technique. This passive-active alignment process has the potential of cost-effective array packaging of edge-emitting devices.

Datta, Madhumita

118

Path-integral ground-state Monte Carlo study of two-dimensional solid He4  

NASA Astrophysics Data System (ADS)

We have studied a two-dimensional (2D) triangular commensurate crystal of He4 with the exact T=0K path-integral ground-state (PIGS) Monte Carlo method. We have projected onto the true ground state two qualitatively different wave functions, a Jastrow-Nosanow wave function and a translationally invariant shadow wave function. The PIGS method passes this hard test of validity and applicability by obtaining the convergence to the same properties, both the diagonal ones as well as the off-diagonal one-body density matrix ?1 . Thus, the commensurate 2D He4 crystal at T=0K is exactly solved, we find no Bose-Einstein condensation (BEC), and ?1 shows a dominant exponential decay in the large distance range. The structure found in ?1 is due to virtual vacancy-interstitial pairs and this shows up in the momentum distribution. Our result indicates that BEC in 2D solid He4 can only arise in the presence of some kind of disorder, either intrinsic or extrinsic.

Vitali, E.; Rossi, M.; Tramonto, F.; Galli, D. E.; Reatto, L.

2008-05-01

119

4He adsorption on a single graphene sheet: Path-integral Monte Carlo study  

NASA Astrophysics Data System (ADS)

We have performed path-integral Monte Carlo calculations to study 4He adsorption on a single graphene sheet. The 4He-substrate interaction was assumed to be a pairwise sum of the helium-carbon potentials constructed by Carlos and Cole to fit helium scattering data from a graphite surface. We employed both an anisotropic 6-12 Lennard-Jones potential and a spherical 6-12 potential. For both potentials, the first 4He layer has the C1/3 commensurate structure at a surface density of 0.0636 Å-2. Vacancy states created in the C1/3 commensurate solid, however, behave differently depending on the 4He-substrate interaction: a cluster of localized vacancies are formed with the fully anisotropic 6-12 pair potentials while mobile vacancies are found to induce finite superfluid fractions with the substrate potential based on only the isotropic parts of the inter-atomic pair potentials. For the second helium layer we find that exchange among 4He adatoms results in quantum melting of a C7/12 commensurate structure, which is registered to a first-layer triangular solid. The possible stabilization of this commensurate structure with the addition of 3He impurities is discussed.

Kwon, Yongkyung; Ceperley, David M.

2012-06-01

120

Monte Carlo simulation studies of lipid order parameter profiles near integral membrane proteins.  

PubMed Central

Monte Carlo simulation techniques have been applied to a statistical mechanical lattice model in order to study the coherence length for the spatial fluctuations of the lipid order parameter profiles around integral membrane proteins in dipalmitoyl phosphatidylcholine bilayers. The model, which provides a detailed description of the pure lipid bilayer main transition, incorporates hydrophobic matching between the lipid and protein hydrophobic thicknesses as a major contribution to the lipid-protein interactions in lipid membranes. The model is studied at low protein-to-lipid ratios. The temperature dependence of the coherence length is found to have a dramatic peak at the phase transition temperature. The dependence on protein circumference as well as hydrophobic length is determined and it is concluded that in some cases the coherence length is much longer than previously anticipated. The long coherence length provides a mechanism for indirect lipid-mediated protein-protein long-range attraction and hence plays an important role in regulating protein segregation. Images FIGURE 5 FIGURE 6

Sperotto, M M; Mouritsen, O G

1991-01-01

121

Path integral Monte Carlo study of quantum-hard sphere solids.  

PubMed

A path integral study of the fcc, hcp, and bcc quantum hard-sphere solids is presented. Ranges of densities within the interval of reduced de Broglie wavelengths 0.2??B(*)?0.8 have been analyzed using Monte Carlo simulations with Cao-Berne propagator. Energies, pressures, and structural quantities (pair radial correlation functions, centroid structure factors, and Steinhardt order parameters) have been computed. Also, applications of the Einstein crystal technique [L. M. Sese?, J. Chem. Phys. 126, 164508 (2007)] have been made to compute the free energies of the fcc and hcp solids. Some technical points related to the latter technique are discussed, and it is shown that these calculations produce consistent results with increasing sample sizes. The fluid-solid (fcc and hcp) equilibria have been studied, thus completing prior work by this author on the fluid-fcc equilibrium. Within the accuracy attained no significant differences between the relative stabilities of the fcc and hcp lattices have been detected. The bcc case stands apart from the other two lattices, as the simulations lead either to irregular lattices (two types) that keep some traces of bcc-memory, or to spontaneous transitions to hcp-like lattices. The latter transitions make manifestly clear the potential repercussions that the quantum hard-sphere behavior can have on solid-solid equilibria at low temperatures in real systems (e.g., helium). PMID:23901988

Sesé, Luis M

2013-07-28

122

A path-integral Monte Carlo study of a small cluster: The Ar trimer  

NASA Astrophysics Data System (ADS)

The Ar3 system has been studied between T=0 K and T=40 K by means of a path-integral Monte Carlo (PIMC) method. The behavior of the average energy in terms of the temperature has been explained by comparison with results obtained with the thermal averaged rovibrational spectra estimated via: (i) a quantum mechanical method based on distributed Gaussian functions for the interparticle distances and (ii) an analytical model which precisely accounts for the participation of the dissociative continua Ar2+Ar and Ar+Ar+Ar. Beyond T~20 K, the system explores floppier configurations than the rigid equilateral geometry, as linear and Ar-Ar2-like arrangements, and fragmentates around T~40 K. A careful investigation of the specific heat in terms of a confining radius in the PIMC calculation seems to discard a proper phase transition as in larger clusters, in apparent contradiction with previous reports of precise values for a liquid-gas transition. The onset of this noticeable change in the dynamics of the trimer occurs, however, at a remarkably low value of the temperature in comparison with Arn systems formed with more Ar atoms. Quantum mechanical effects are found of relevance at T<=15 K, with both energies and radial distributions obtained with a quantum PIMC deviating from the corresponding classical results, thus precluding exclusively classical approaches for a precise description of the system at this low temperature range.

Pérez de Tudela, R.; Márquez-Mijares, M.; González-Lezana, T.; Roncero, O.; Miret-Artés, S.; Delgado-Barrio, G.; Villarreal, P.

2010-06-01

123

Path-integral Monte Carlo simulation of the recombination of two Al atoms embedded in parahydrogen  

NASA Astrophysics Data System (ADS)

We report the use of path-integral Monte Carlo (PIMC) simulations in the study of the stability against recombination of two Al atoms trapped in solid parahydrogen (pH2) at 4 K. The many-body interactions involving open-shell Al atoms are described with a pairwise additive Hamiltonian model. To estimate the lifetime against recombination, we use PIMC simulations to define an effective potential averaged over the position of the pH2 molecules, followed by a transition-state treatment. Different initial embedding sites are explored. If the initial substitution sites are within a distance of ~13 bohrs, the Al atoms will significantly distort the lattice structure to allow recombination, with an accompanying release of energy during the process. For substitution distances longer than ~14 bohrs, the dispersion of Al atoms is shown to be metastable, with lifetimes varying from ~30 min to several days. The electronic anisotropy is a factor that helps to stabilize the dispersion.

Wang, Qian; Alexander, Millard H.

2006-01-01

124

An anthropomorphic phantom integrated EGS4 Monte Carlo code and its application in Compton probe  

Microsoft Academic Search

An EGS4 Monte Carlo Code incorporated with a digitized anthropomorphic phantom is presented. With this Monte Carlo program, new imaging techniques and devices can be investigated accurately under realistic clinical conditions without conducting experiments in living subjects. Imaging quality can be improved by analyzing the image formation procedure with detailed interaction physics. As an example, its application in predicting the

L. Zhangl; S. J. Wilderman; N. H. Clinthorne; W. L. Rogers

2000-01-01

125

Bayesian Parameter Inference by Markov Chain Monte Carlo with Hybrid Fitness Measures: Theory and Test in Apoptosis Signal Transduction Network  

PubMed Central

When model parameters in systems biology are not available from experiments, they need to be inferred so that the resulting simulation reproduces the experimentally known phenomena. For the purpose, Bayesian statistics with Markov chain Monte Carlo (MCMC) is a useful method. Conventional MCMC needs likelihood to evaluate a posterior distribution of acceptable parameters, while the approximate Bayesian computation (ABC) MCMC evaluates posterior distribution with use of qualitative fitness measure. However, none of these algorithms can deal with mixture of quantitative, i.e., likelihood, and qualitative fitness measures simultaneously. Here, to deal with this mixture, we formulated Bayesian formula for hybrid fitness measures (HFM). Then we implemented it to MCMC (MCMC-HFM). We tested MCMC-HFM first for a kinetic toy model with a positive feedback. Inferring kinetic parameters mainly related to the positive feedback, we found that MCMC-HFM reliably infer them using both qualitative and quantitative fitness measures. Then, we applied the MCMC-HFM to an apoptosis signal transduction network previously proposed. For kinetic parameters related to implicit positive feedbacks, which are important for bistability and irreversibility of the output, the MCMC-HFM reliably inferred these kinetic parameters. In particular, some kinetic parameters that have experimental estimates were inferred without using these data and the results were consistent with experiments. Moreover, for some parameters, the mixed use of quantitative and qualitative fitness measures narrowed down the acceptable range of parameters.

Murakami, Yohei; Takada, Shoji

2013-01-01

126

Hybridization Promotes Evolvability in African Cichlids: Connections Between Transgressive Segregation and Phenotypic Integration  

Microsoft Academic Search

Hybridization is a potential source of novel variation through (1) transgressive segregation, and (2) changes in the patterns\\u000a and strength of phenotypic integration. We investigated the capacity of hybridization to generate novel phenotypic variation\\u000a in African cichlids by examining a large F2 population generated by hybridizing two Lake Malawi cichlid species with differently\\u000a shaped heads. Our morphometric analysis focused on

Kevin J. ParsonsYoung; Young H. Son; R. Craig Albertson

127

Integration of Wind-Turbine Generators (WTGs) into Hybrid Distributed Generation Systems in Extreme Northern Climates  

Microsoft Academic Search

This paper discusses the effects of integrating wind-turbine generators (WTGs) into hybrid distributed generation systems in extreme northern climates. The hybrid performance analysis tool presented incorporates the added features of dynamic modeling and the graphical user interface available in MATLAB™ Simulink. The model currently consists of a diesel-electric generator, a battery storage bank, and WTGs connected to a common grid

RICHARD W. WIES; RONALD A. JOHNSON; ASHISH N. AGRAWAL

2005-01-01

128

Design of Cruciform Substrate-Integrated Waveguide Hybrids Based on H-Plane Planar Circuit Approach  

Microsoft Academic Search

This paper suggests a novel cruciform substrate- integrated waveguide quadrature 3-dB hybrid, and shows the frequency characteristics of hybrids designed at various center frequencies using the H-plane planar circuit approach. As a result, relatively flat coupling properties are realized in a compact structure.

I. Ohta; K. Toda; M. Kishihara; T. Kawai

2007-01-01

129

Modelling and reduction techniques for studies of integrated hybrid vehicle systems  

Microsoft Academic Search

Models of integrated vehicle systems are essential for designing hybrid vehicles by means of simulation-based optimization. Given the complexity of hybrid vehicle systems, designing is a time consuming process that requires the evaluation of a large number of different design configurations. Modelling and simulation can significantly reduce the design time through efficient design evaluations and reduced number of prototypes built.

Loucas S. Louca; B. Umut Yildir

2006-01-01

130

A hybrid silicon sampled grating DBR laser integrated with an electroabsorption modulator using quantum well intermixing  

Microsoft Academic Search

We demonstrate the first hybrid silicon sampled grating DBR laser integrated with an electroabsorption modulator. Laser operation >45degC is achieved with output power >0.5 mW. Modulator bandwidth is >2 GHz.

M. N. Sysak; J. O. Anthes; O. Raday; J. E. Bowers; R. Jones

2008-01-01

131

Integration, Testing, and Validation of a Small Hybrid-Electric Remotely-Piloted Aircraft.  

National Technical Information Service (NTIS)

Parallel hybrid-electric technology offers a wide variety of new mission capabilities including low-observable loiter operations and increased fuel efficiency for small remotely-piloted aircraft. This research focused on the integration, validation, and t...

J. K. Ausserer

2012-01-01

132

Hybrid-integrated coherent receiver using silica-based planar lightwave circuit technology  

NASA Astrophysics Data System (ADS)

A hybrid-integrated coherent receiver module has been achieved using flip-chip bonding technology, consisting of a silica-based 90°-hybrid planar lightwave circuit (PLC) platform, a spot-size converter integrated waveguide photodiode (SSC-WG-PD), and a dual-channel transimpedance amplifier (TIA). The receiver module shows error-free operation up to 40Gb/s and OSNR sensitivity of 11.5 dB for BER = 10-3 at 25 Gb/s.

Kim, Jong-Hoi; Choe, Joong-Seon; Choi, Kwang-Seong; Youn, Chun-Ju; Kim, Duk-Jun; Jang, Sun-Hyok; Kwon, Yong-Hwan; Nam, Eun-Soo

2011-11-01

133

Bead-Fourier path-integral Monte Carlo method applied to systems of identical particles  

SciTech Connect

To make the path-integral Monte Carlo (PIMC) method more effective and practical in application to systems of identical particles with strong interactions, we introduce a combined bead-Fourier (BF) PIMC approach with the ordinary bead method and the Fourier PIMC method of Doll and Freeman [J. Chem. Phys. {bold 80}, 2239 (1984); {bold 80}, 5709 (1984)] being its extreme cases. Optimal choice of the number of beads and of Fourier components enables us to reproduce reliably the ground-state energy and electron density distribution in the H atom as well as the exact data for the harmonic oscillator. Applying the BF method to systems of identical particles we use the procedure of simultaneous accounting for all classes of permutations suggested in the previous work [Phys. Rev. A {bold 48}, 4075 (1993)] with subsequent symmetrization of the exchange factor in the weight function to make the sign problem milder. A procedure of random walk in the spin space enables us to obtain spin-dependent averages. We derived exact partition functions and canonical averages for a model system of N noninteracting identical particles (N=2,3,4,{hor_ellipsis}) with the spin (fermions or bosons) in a d-dimensional harmonic field (d=1,2,3) that provided a reliable test of the developed MC procedures. Simulations for N=2,3 reproduce well the exact dependencies. Further simulations showed how gradual switching on of the electrostatic repulsion between particles in this system results in significant weakening of the exchange effects. {copyright} {ital 1997} {ital The American Physical Society}

Vorontsov-Velyaminov, P.N.; Nesvit, M.O.; Gorbunov, R.I. [Faculty of Physics, St. Petersburg State University, 198904, St. Petersburg (Russia)

1997-02-01

134

Streamline Integration using MPI-Hybrid Parallelism on a Large Multi-Core Architecture  

SciTech Connect

Streamline computation in a very large vector field data set represents a significant challenge due to the non-local and datadependentnature of streamline integration. In this paper, we conduct a study of the performance characteristics of hybrid parallel programmingand execution as applied to streamline integration on a large, multicore platform. With multi-core processors now prevalent in clustersand supercomputers, there is a need to understand the impact of these hybrid systems in order to make the best implementation choice.We use two MPI-based distribution approaches based on established parallelization paradigms, parallelize-over-seeds and parallelize-overblocks,and present a novel MPI-hybrid algorithm for each approach to compute streamlines. Our findings indicate that the work sharing betweencores in the proposed MPI-hybrid parallel implementation results in much improved performance and consumes less communication andI/O bandwidth than a traditional, non-hybrid distributed implementation.

Camp, David; Garth, Christoph; Childs, Hank; Pugmire, Dave; Joy, Kenneth I.

2010-11-01

135

A Class of Ceramic-Based Chip Inductors for Hybrid Integration in Power Supplies  

Microsoft Academic Search

A review of some of the available technologies for inductor hybrid integration is given in this paper. In accordance with low voltage and high current requirements, low-temperature co-fired ceramics (LTCC) technology is identified to be a suitable candidate for power electronics passives integration. This paper will discuss the various limitations of the current LTCC processing technique and introduce a fabrication

Michele H. Lim; Jacobus. D. van Wyk; F. C. Lee; Khai D. T. Ngo

2008-01-01

136

A new hybrid mode boundary integral method for analysis of MMIC waveguides with complicated cross section  

Microsoft Academic Search

A boundary integral formulation for quasistatic, transverse electric, transverse magnetic, and hybrid wave analysis of open or shielded waveguides with arbitrary multiregion cross section is presented. A special form of boundary integral equation is derived to make possible the numerical treatment of cornered geometries. Subsequently, operator equations including source terms are given for the analysis of arbitrary two-dimensional structures. The

W. Schroeder; I. Wolff

1989-01-01

137

A CMOS Integrated DNA-chip for hybridization detection with digital output  

Microsoft Academic Search

A CMOS integrated circuit hosting an array of 80 sensors for DNA hybridization detection was designed. Each biosensor is made up of a FET device whose current is modulated by DNA electric charge. The chip incorporates integrated temperature detection for precise assay control and features programmable signal conditioning, amplification and A\\/D conversion. Successful pre-and post-layout simulations are provided.

M. Barbara; Alessandra Caboni; Daniela Loi

2007-01-01

138

A CMOS integrated circuit for DNA hybridization detection with digital output and temperature control  

Microsoft Academic Search

A CMOS integrated circuit hosting an array of 80 sensors for DNA hybridization detection was designed. Each biosensor is made up of a FET device whose current is modulated by DNA electric charge. The chip incorporates integrated temperature detection for precise assay control and features programmable signal conditioning, amplification and A\\/D conversion. Successful pre- and post-layout simulations are provided.

Alessandra Caboni; Daniela Loi; M. Barbara

2007-01-01

139

Transient modeling of an integrated charger for a plug-in hybrid electric vehicle  

Microsoft Academic Search

This paper considers a permanent magnet assisted synchronous reluctance (PMSynRel) machine for an integrated charger application for use in a plug-in hybrid electric vehicle (PHEV). The integrated charger functionality means that the machine is also used when the battery is charged from the electrical grid. A finite element model (FEM) is presented from which a transient model of the complete

Shuang Zhao; Saeid Haghbin; Oskar Wallmark; Mats Leksell; Sonja Lundmark; Ola Carlson

2011-01-01

140

A hybrid approach to device integration on a genetic analysis platform  

NASA Astrophysics Data System (ADS)

Point-of-care (POC) systems require significant component integration to implement biochemical protocols associated with molecular diagnostic assays. Hybrid platforms where discrete components are combined in a single platform are a suitable approach to integration, where combining multiple device fabrication steps on a single substrate is not possible due to incompatible or costly fabrication steps. We integrate three devices each with a specific system functionality: (i) a silicon electro-wetting-on-dielectric (EWOD) device to move and mix sample and reagent droplets in an oil phase, (ii) a polymer microfluidic chip containing channels and reservoirs and (iii) an aqueous phase glass microarray for fluorescence microarray hybridization detection. The EWOD device offers the possibility of fully integrating on-chip sample preparation using nanolitre sample and reagent volumes. A key challenge is sample transfer from the oil phase EWOD device to the aqueous phase microarray for hybridization detection. The EWOD device, waveguide performance and functionality are maintained during the integration process. An on-chip biochemical protocol for arrayed primer extension (APEX) was implemented for single nucleotide polymorphism (SNiP) analysis. The prepared sample is aspirated from the EWOD oil phase to the aqueous phase microarray for hybridization. A bench-top instrumentation system was also developed around the integrated platform to drive the EWOD electrodes, implement APEX sample heating and image the microarray after hybridization.

Brennan, Des; Jary, Dorothee; Kurg, Ants; Berik, Evgeny; Justice, John; Aherne, Margaret; Macek, Milan; Galvin, Paul

2012-10-01

141

Path-integral and effective potential Monte Carlo simulations of liquid nitrogen, hard-sphere and Lennard-Jones potentials  

NASA Astrophysics Data System (ADS)

The quantum features in liquid nitrogen at T = 66 K are studied. Quantum Monte Carlo runs have been performed using different one-centre interaction potentials and strategies. Hard-sphere, Lennard-Jones and quantum effective potential (Feynman-Hibbs, Wigner-Kirkwood) models are the basic ingredients for carrying out calculations, which are classical, semiclassical and of path-integral nature. Relevant thermodynamic and structural data are presented. The results show how the magnitude of hard-sphere quantum effect is dramatically reduced in using smooth potentials. The Wigner-Kirkwood fluid is, the closest to the 'exact' path-integral fluid compared with other effective potential models. The results obtained from path-integral MC account for the available experimental information.

Sesé, Luis M.

142

Integration Profile and Safety of an Adenovirus Hybrid-Vector Utilizing Hyperactive Sleeping Beauty Transposase for Somatic Integration  

PubMed Central

We recently developed adenovirus/transposase hybrid-vectors utilizing the previously described hyperactive Sleeping Beauty (SB) transposase HSB5 for somatic integration and we could show stabilized transgene expression in mice and a canine model for hemophilia B. However, the safety profile of these hybrid-vectors with respect to vector dose and genotoxicity remains to be investigated. Herein, we evaluated this hybrid-vector system in C57Bl/6 mice with escalating vector dose settings. We found that in all mice which received the hyperactive SB transposase, transgene expression levels were stabilized in a dose-dependent manner and that the highest vector dose was accompanied by fatalities in mice. To analyze potential genotoxic side-effects due to somatic integration into host chromosomes, we performed a genome-wide integration site analysis using linker-mediated PCR (LM-PCR) and linear amplification-mediated PCR (LAM-PCR). Analysis of genomic DNA samples obtained from HSB5 treated female and male mice revealed a total of 1327 unique transposition events. Overall the chromosomal distribution pattern was close-to-random and we observed a random integration profile with respect to integration into gene and non-gene areas. Notably, when using the LM-PCR protocol, 27 extra-chromosomal integration events were identified, most likely caused by transposon excision and subsequent transposition into the delivered adenoviral vector genome. In total, this study provides a careful evaluation of the safety profile of adenovirus/Sleeping Beauty transposase hybrid-vectors. The obtained information will be useful when designing future preclinical studies utilizing hybrid-vectors in small and large animal models.

Zhang, Wenli; Muck-Hausl, Martin; Wang, Jichang; Sun, Chuanbo; Gebbing, Maren; Miskey, Csaba; Ivics, Zoltan; Izsvak, Zsuzsanna; Ehrhardt, Anja

2013-01-01

143

Integration profile and safety of an adenovirus hybrid-vector utilizing hyperactive sleeping beauty transposase for somatic integration.  

PubMed

We recently developed adenovirus/transposase hybrid-vectors utilizing the previously described hyperactive Sleeping Beauty (SB) transposase HSB5 for somatic integration and we could show stabilized transgene expression in mice and a canine model for hemophilia B. However, the safety profile of these hybrid-vectors with respect to vector dose and genotoxicity remains to be investigated. Herein, we evaluated this hybrid-vector system in C57Bl/6 mice with escalating vector dose settings. We found that in all mice which received the hyperactive SB transposase, transgene expression levels were stabilized in a dose-dependent manner and that the highest vector dose was accompanied by fatalities in mice. To analyze potential genotoxic side-effects due to somatic integration into host chromosomes, we performed a genome-wide integration site analysis using linker-mediated PCR (LM-PCR) and linear amplification-mediated PCR (LAM-PCR). Analysis of genomic DNA samples obtained from HSB5 treated female and male mice revealed a total of 1327 unique transposition events. Overall the chromosomal distribution pattern was close-to-random and we observed a random integration profile with respect to integration into gene and non-gene areas. Notably, when using the LM-PCR protocol, 27 extra-chromosomal integration events were identified, most likely caused by transposon excision and subsequent transposition into the delivered adenoviral vector genome. In total, this study provides a careful evaluation of the safety profile of adenovirus/Sleeping Beauty transposase hybrid-vectors. The obtained information will be useful when designing future preclinical studies utilizing hybrid-vectors in small and large animal models. PMID:24124483

Zhang, Wenli; Muck-Hausl, Martin; Wang, Jichang; Sun, Chuanbo; Gebbing, Maren; Miskey, Csaba; Ivics, Zoltan; Izsvak, Zsuzsanna; Ehrhardt, Anja

2013-10-04

144

INTEGRATED KENO MONTE CARLO TRANSPORT FOR 3-D DEPLETION WITH SCALE  

Microsoft Academic Search

Accurate calculation of the depletion of nuclear materials requires careful determination of the neutron flux density and spectrum in the region(s) of interest. Increasing complexity in reactor designs, evolutionary concepts, and nonreactor applications such as safeguards, security, and nonproliferation, is beginning to require robust geometrical modeling capabilities to capture neutron transport for complex configurations. Monte Carlo transport methods offer the

Stephen M. Bowman; Mark D. DeHart; Lester M. Petrie

145

Hybrid organic-inorganic nanostructures for integration with photonic atoms  

Microsoft Academic Search

In this paper, we report on optical properties of a novel type of the hybrid nanostructures that combine CdTe colloidal quantum dots (QDs) with organic dye molecules in J-aggregate state. Formed QD\\/J-aggregate system shows the broadband absorption in visible and ultraviolet part of the spectrum typical of quantum dots, along with the narrow emission linewidth characteristic of J-band emitters (~15

Diana Savateeva; Dimitry Melnikau; Yury P. Rakovich

2011-01-01

146

Hybrid rectenna and monolithic integrated zero-bias microwave rectifier  

Microsoft Academic Search

In this study, we have developed a hybrid sensitive rectenna (rectifier + antenna) system at 2.45 GHz. To achieve this system, we have first optimized and validated a zero-bias microwave sensitive rectifier using commercial Schottky diodes. We have then optimized and achieved a 2times2 patch antenna array, which is associated to the microwave rectifier in order to validate the rectenna

Jamal Zbitou; Mohamed Latrach; Serge Toutain

2006-01-01

147

Streamline Integration Using MPI-Hybrid Parallelism on a Large Multicore Architecture  

SciTech Connect

Streamline computation in a very large vector field data set represents a significant challenge due to the nonlocal and data-dependent nature of streamline integration. In this paper, we conduct a study of the performance characteristics of hybrid parallel programming and execution as applied to streamline integration on a large, multicore platform. With multicore processors now prevalent in clusters and supercomputers, there is a need to understand the impact of these hybrid systems in order to make the best implementation choice. We use two MPI-based distribution approaches based on established parallelization paradigms, parallelize over seeds and parallelize over blocks, and present a novel MPI-hybrid algorithm for each approach to compute streamlines. Our findings indicate that the work sharing between cores in the proposed MPI-hybrid parallel implementation results in much improved performance and consumes less communication and I/O bandwidth than a traditional, nonhybrid distributed implementation.

Garth, Christoph [unknown

2011-01-01

148

Double Ridged 180$^{\\\\circ}$ Hybrid Power Divider With Integrated Band Pass Filter  

Microsoft Academic Search

We describe the design, construction and perfor- mance of a 180 hybrid power divider with integrated band pass filter for L-band (1.3-1.8 GHz). The hybrid is based on a cavity and two novel broadband coaxial-to-double ridged waveguide transitions. The design was optimized using a commercial 3-D electromagnetic simulator. The device was tested at room and cryogenic temperature. At the physicaltemperature

Giuseppe Valente; Alessandro Navarrini; Tonino Pisanu

2011-01-01

149

Ultra-High-Speed Multichannel Data Transmission Using Hybrid Substrate Integrated Waveguides  

Microsoft Academic Search

Hybrid substrate integrated waveguides (SIWs) are proposed as an alternative low-cost interconnect solution to enable ultra-high-speed signal transmission. The SIW serves as a bandpass data transmission channel providing 15-GHz bandwidth. The hybrid structure utilizes the available low-pass frequency region below the cutoff frequency by adding striplines inside the waveguide. This technique of substrate reuse allows several independent data channels to

Asanee Suntives; Ramesh Abhari

2008-01-01

150

Hybrid simulation system study of SINS\\/CNS integrated navigation  

Microsoft Academic Search

In flight tests, to demonstrate the performance of integrated navigation systems, which are strapdown inertial navigation systems\\/celestial navigation systems (SINS\\/CNS), will involve a lot of effort and a heavy financial budget. So, it is important to design a functional self-contained hardware in a loop simulation system on the ground for solving the verification of SINS\\/CNS integrated navigation systems. Aiming at

Quan Wei; Fang Jiancheng; Xu Fan; Sheng Wei

2008-01-01

151

Development of Integrated Motor Assist Hybrid System: Development of the 'Insight', a Personal Hybrid Coupe  

Microsoft Academic Search

This paper presents the technical approach used to design and develop the powerplant for the Honda Insight, a new motor assist hybrid vehicle with an overall development objective of just half the fuel consumption of the current Civic over a wide range of driving conditions. Fuel consumption of 35km\\/L (Japanese 10-15 mode), and 3.4L\\/100km (98\\/69\\/EC) was realized. To achieve this,

Kaoru Aoki; Shigetaka Kuroda; Shigemasa Kajiwara; Hiromitsu Sato; Yoshio Yamamoto

2000-01-01

152

Hybridization of Architectural Styles for Integrated Enterprise Information Systems  

NASA Astrophysics Data System (ADS)

Current enterprise systems engineering theory does not provide adequate support for the development of information systems on demand. To say more precisely, it is forming. This chapter proposes the main architectural decisions that underlie the design of integrated enterprise information systems. This chapter argues for the extending service-oriented architecture - for merging it with component-based paradigm at the design stage and using connectors of different architectural styles. The suitability of general-purpose language SysML for the modeling of integrated enterprise information systems architectures is described and arguments pros are presented.

Bagusyte, Lina; Lupeikiene, Audrone

153

A Hybrid Object Matching Method for Deep Web Information Integration  

Microsoft Academic Search

Object matching is a crucial step to integration of Deep Web sources. Existing methods suppose that record extraction and attribute segmentation are of high accuracy. But because of limitation of extraction techniques, information gained through the above methods is often incomplete. If we match object base on noisy and incomplete information, we can not achieve satisfactory performance. This paper proposes

Pengpeng Zhao; Chao Lin; Wei Fang; Zhiming Cui

2007-01-01

154

Integrating DNA With Semiconductor Materials: Bio-inorganic Hybrid Devices  

NASA Astrophysics Data System (ADS)

A method for the automated solid-phase synthesis of DNA on a semiconductor chip with the potential for photolithography to fabricate hybrid electronic-DNA devices was developed. The on-chip oligonucleotide synthetic quality was comparable to standard CPG supports as confirmed by HPLC and gel electrophoresis. Enzymatic manipulation of the immobilised ssDNA was possible by radiolabelling with T4 polynucleotide kinase. Spatial control, afforded by photolithography, was visualised by phosphorimaging radiolabelled dsDNA. The charge transfer properties of DNA were investigated by the association of Ru(NH3)63+ with the phosphate backbone and by intercalation with redox active methylene blue. Additionally ferrocene modified nucleosides were incorporated into oligonucleotides to act as electronic mediators for charge transfer. Initial investigations into the effect of the redox group on the nucleobase indicated their potential for use as bioelectronic building blocks for incorporation into silicon based molecular systems.

Pike, Andrew R.; Lie, Lars H.; Patole, Samson N.; Ryder, Lyndsey C.; Connolly, Bernard. A.; Horrocks, Benjamin R.; Houlton, Andrew

2002-11-01

155

Hybrid-integrated prism array optoelectronic targeting system  

NASA Astrophysics Data System (ADS)

This investigation proposes a cost-effective, compact, and robust optoelectronic targeting system for measuring ballistic impact velocity and the distribution of projectile motion. The major elements of this system are four photo-gates hybridized by compound one-dimensional prism array and analog/digital electronic components. The number of light sources and photodetectors used in a photo-gate was reduced to one pair of light source and photodetector. The average velocity and location of the projectile are determined according to the measured time intervals (˜10- s) passing each pair. The system can accurately measure the velocity of a bullet as it leaves a gun barrel, as well as the velocity at specific points along the trajectory outside the firearm. Additionally, the system uses a widespread low-powered laser pointer as a light source. Compared with other optoelectronic targeting systems that use high-powered lasers, the proposed system is both economical and safe.

Chang, C. C.; Chang, H. C.; Tang, L. C.; Young, W. K.; Wang, J. C.; Huang, K. L.

2005-11-01

156

HiRel: Hybrid Automated Reliability Predictor (HARP) Integrated Reliability Tool System, (Version 7.0). Volume 2: HARP Tutorial.  

National Technical Information Service (NTIS)

The Hybrid Automated Reliability Predictor (HARP) integrated Reliability (HiRel) tool system for reliability/availability prediction offers a toolbox of integrated reliability/availability programs that can be used to customize the user's application in a...

E. Rothmann J. B. Dugan K. S. Trivedi N. Mittal S. J. Bavuso

1994-01-01

157

Electro-absorption modulated 1.55 ?m wavelength selectable DFB array using hybrid integration  

Microsoft Academic Search

We demonstrate for the first time an EA-modulated hybrid integrated wavelength selectable laser comprised of 1.55 ?m DFB laser array and amplifier\\/modulator chips fabricated using a novel spot-size converter integration technique, and optically connected via silica-on-silicon waveguides. The device operates at 2.5 Gbit's over 16 50 GHz spaced channels with SMSR>33 dB, peak power from +1.6 to -6.2 dBm, and

L. J. P. Ketelsen; J. E. Johnson; M. Muehlner; J. V. Gates; M. A. Cappuzzo; J. M. Geary; J. A. Grenko; J. M. Vandenberg; S. K. Sputz; M. W. Focht; E. J. Laskowski; L. T. Gomez; K. G. Glogovsky; C. L. Reynolds; S. N. G. Chu; W. A. Gault; M. S. Hybertsen; J. L. Zilko

1999-01-01

158

Streamline Integration using MPI-Hybrid Parallelism on a Large Multi-Core Architecture  

Microsoft Academic Search

Streamline computation in a very large vector field data\\u000aset represents a significant challenge due to the non-local and datadependentnature of streamline integration. In this paper, we conduct a\\u000astudy of the performance characteristics of hybrid parallel programmingand execution as applied to streamline integration on a large, multicore\\u000aplatform. With multi-core processors now prevalent in clustersand supercomputers, there is a

David Camp; Christoph Garth; Hank Childs; Dave Pugmire; Kenneth I. Joy

2010-01-01

159

LSE-mode balun for hybrid integration of NRD-guide and microstrip line  

Microsoft Academic Search

A recently proposed hybrid integration technology of NRD-guide and planar circuits provides an alternative for exploiting advantageous features of the two complementary structures in view of three-dimensional circuit design at millimeter-wave frequencies. Such an integration scheme has been developed for use of the second fundamental mode (LSM) having the lowest transmission loss. In this work, a new balun structure (transition)

Abdallah Bacha; Ke Wu

1998-01-01

160

A CMOS, fully integrated sensor for electronic detection of DNA hybridization  

Microsoft Academic Search

An integrated field-effect device for fully electronic deoxyribonucleic acid (DNA) detection was realized in a standard CMOS process. The device is composed of a floating-gate MOS transistor, a control-capacitor acting as integrated counterelectrode, and an exposed active area for DNA immobilization. The drain-current of the transistor is modulated by the electric charge carried by the DNA molecules. After DNA hybridization,

Massimo Barbaro; Annalisa Bonfiglio; Luigi Raffo; Andrea Alessandrini; Paolo Facci; I. Barakbarak

2006-01-01

161

Hybrid2: combining the three-dimensional hybrid finite element-boundary integral technique for planar multilayered media with the uniform geometrical theory of diffraction  

Microsoft Academic Search

The fully three-dimensional (3-D) hybrid finite element (FE)-boundary integral (BI) technique is extended by further hybridization with the uniform geometrical theory of diffraction (UTD) resulting in a so-called hybrid2 FE-BI-UTD approach. The formulation is capable of modeling arbitrarily shaped strongly inhomogeneous objects together with electrically large obstacles of relatively simple shape within the common environment of a planar-multilayered medium. The

Mudrik Alaydrus; Volkert Hansen; Thomas F. Eibert

2002-01-01

162

Improved Monte Carlo method for evaluating multidimensional integrals. [In Algol, PLI, or FORTRAN for IBM 360\\/75 (FORTRAN listing included)  

Microsoft Academic Search

The goal of this work was to develop an improved Monte Carlo method and implement a computer code for performing automatic integration of multidimensional integrals of the form ..integral..f(X)dX over a closed region in k-dimensional Euclidean space, where X is a point in the space and DX = dxâdxâ...dx\\/sub k\\/. The scheme is ''automatic'' in the sense that it returns

Yuen

1977-01-01

163

Flight tests of a hybrid-centered integrated 3D perspective-view primary flight display  

NASA Astrophysics Data System (ADS)

This paper describes flight tests of a Honeywell Synthetic Vision System (SVS) prototype operating in a hybrid-centered mode on a Primus EpicTM large format display. This novel hybrid mode effectively resolves some cognitive and perceptual human factors issues associated with traditional heading-up or track-up display modes. By integrating synthetic 3D perspective view with advanced Head-Up Display (HUD) symbology in this mode, the test results demonstrate that the hybrid display mode provides clear indications of current track and crab conditions, and is effective in overcoming flight guidance symbology collision and resultant ambiguity. The hybrid-centering SVS display concept is shown to be effective in all phases of flight and is particularly valuable during landing operations with a strong cross-wind. The recorded flight test data from Honeywell's prototype SVS concept at Reno, Nevada on board Honeywell Citation V aircraft will be discussed.

He, Gang; Feyereisen, Thea; Wilson, Blake; Wyatt, Sandy; Engels, Jary

2006-06-01

164

Integrating Role Activity Diagrams and Hybrid IDEF for Business Process Modeling Using MDA  

Microsoft Academic Search

Business process modeling is an important phase dur- ing requirements collection. Usually functional, dynamic and role models are needed. We propose to integrate Role Activity Diagrams and Hybrid IDEF for business process modeling within Model Driven Architecture. Our pro- posal is demonstrated with a sample implementation.

Costin Badica; Maria Teodorescu; Cosmin Spahiu; Amelia Badica; Chris Fox

2005-01-01

165

Fuel cell system integration into a heavy-duty hybrid vehicle: preliminary experimental results  

Microsoft Academic Search

This paper is the second paper dealing with the evaluation of different power sources and hybridization strategies in a heavy-duty vehicle. It focuses on the physical integration of a fuel cell system (FCS) into the vehicle as well as the preliminary experimental results obtained with the FCS coupled to batteries. The vehicle considered here is a mobile research platform (ECCE)

J. Mulot; F. Harel; S. Begot; D. Hissel; I. Rodel; S. Boblet; M. Amiet

2010-01-01

166

Integration of plug-in hybrid electric vehicles into building energy management system  

Microsoft Academic Search

The smart building and plug-in hybrid electric vehicle (PHEV) are two promising emerging technologies. The integration of these two technologies shows great promise in reinforcing the reliability and flexibility in building energy management. The control challenge of the smart building is to maximize the customer comfort with minimum power consumption. Multi-agent technology with particle swarm optimization (PSO) has been proposed

Zhu Wang; Lingfeng Wang; Anastasios I. Dounis; Rui Yang

2011-01-01

167

An Integrated Hybrid Power Supply for Distributed Generation Applications Fed by Nonconventional Energy Sources  

Microsoft Academic Search

A new, hybrid integrated topology, fed by photovoltaic (PV) and fuel cell (FC) sources and suitable for distributed generation applications, is proposed. It works as an uninterruptible power source that is able to feed a certain minimum amount of power into the grid under all conditions. PV is used as the primary source of power operating near maximum power point

Sachin Jain; Vivek Agarwal

2008-01-01

168

Conceptual Integration of Hybridization by Algerian Students Intending to Teach Physical Sciences  

ERIC Educational Resources Information Center

|This work aims to assess the difficulties encountered by students of the Ecole Normale Superieure of Kouba (Algeria) intending to teach physical science in the integration of the hybridization of atomic orbitals. It is a concept that they should use in describing the formation of molecular orbitals ([sigma] and [pi]) in organic chemistry and gaps…

Salah, Hazzi; Dumon, Alain

2011-01-01

169

A hybrid nanorobotic manipulation system integrated with nanorobotic manipulators inside scanning and transmission electron microscopes  

Microsoft Academic Search

A hybrid nanorobotic manipulation system, which is integrated with a nanorobotic manipulator inside a transmission electron microscope (TEM) and nanorobotic manipulators inside a scanning electron microscope (SEM), is presented. The TEM nanomanipulator has been constructed with 4 multi-layer piezoelectric devices for driving in 3 translational degrees of freedoms (DOFs) and a passive 3-DOF sample stage driven by SEM nanorobotic manipulators.

Masahiro Nakajima; Fumihito Arai; Lixin Dong; Toshio Fukuda

2004-01-01

170

Managing change in an integrated school--a Hong Kong hybrid experience  

Microsoft Academic Search

Following the world trend of inclusion in education, many schools in Hong Kong have started including students with special needs in the regular classrooms. Given the unique educational context of Hong Kong as 'East meets West', and given that inclusion is essentially a concept from the West, this paper argues that Hong Kong's integration has its unique hybrid features. This

Pattie Luk Fong Yuk Yee

2005-01-01

171

A Hybrid Integrated Silicon Diode Array for Visible Earth-Horizon Sensing.  

National Technical Information Service (NTIS)

An earth-horizon sensing device which operates principally in the visible portion of the spectrum has been designed as a hybrid integrated circuit. The circuit was fabricated and tested for use in the LES-8/9 communications satellites as part of the syste...

F. J. Bachner R. W. Mountain A. G. Foyt R. A. Cohen W. H. McGonagle

1974-01-01

172

Integrated planar terahertz resonators for femtomolar sensitivity label-free detection of DNA hybridization  

Microsoft Academic Search

A promising label-free approach for the analysis of genetic material by means of detecting the hybridization of polynucleotides with electromagnetic waves at terahertz (THz) frequencies is presented. Using an integrated waveguide approach, incorporating resonant THz structures as sample carriers and transducers for the analysis of the DNA molecules, we achieve a sensitivity down to femtomolar levels. The approach is demonstrated

Michael Nagel; Peter Haring Bolivar; Martin Brucherseifer; Heinrich Kurz; Anja Bosserhoff; Reinhard Buttner

2002-01-01

173

Efficient ethanol recovery from fermentation broths with integrated distillation-vapor permeation hybrid process  

EPA Science Inventory

The energy demand of distillation-molecular sieve systems for ethanol recovery/dehydration can be significant, particularly for dilute solutions. An alternative hybrid process integrating vapor stripping (like a beer still) with vapor compression and a vapor permeation membrane s...

174

Hybrid simultaneous localization and map building: a natural integration of topological and metric  

Microsoft Academic Search

In this paper the metric and topological paradigms are integrated in a hybrid system for both localization and map building. A global topological map connects local metric maps, allowing a compact environment model, which does not require global metric consistency and permits both precision and robustness. Furthermore, the approach handles loops in the environment during automatic mapping by means of

Nicola Tomatis; Illah R. Nourbakhsh; Roland Siegwart

2003-01-01

175

The issue of plug-in hybrid electric vehicles' grid integration and its control solution  

Microsoft Academic Search

In this paper, a bi-directional battery charger is applied as an interface between plug-in hybrid electric vehicles and the grid. The major issue of using power electronics interface for grid integration of PHEVs is high frequency resonance. This resonance is caused by a high order filter, which is composed of the charger's LC filter and the grid impedance. An active

Xiaohu Zhou; Jun Li; Zhigang Liang; A. Huang; S. Bhattacharya

2010-01-01

176

Integration of Neuroscience and Endocrinology in Hybrid PBL Curriculum  

NSDL National Science Digital Library

At the University of Missouri-Columbia, the medical school employs a problem-based learning curriculum that began in 1993. Since the curriculum was changed, student performance on step 1 of the United States Medical Licensing Examination has significantly increased from slightly below the national average to almost one-half a standard deviation above the national mean. In the first and second years, classes for students are organized in classes or blocks that are 8 wk long, followed by 1 wk for evaluation. Initially, basic science endocrinology was taught in the fourth block of the first year with immunology and molecular biology. Student and faculty evaluations of the curriculum indicated that endocrinology did not integrate well with the rest of the material taught in that block. To address these issues, basic science endocrinology was moved into another block with neurosciences. We integrate endocrinology with neurosciences by using the hypothalamus and its role in neuroendocrinology as a springboard for endocrinology. This is accomplished by using clinical cases with clear neuroscience and endocrinology aspects such as CushingÃÂs disease and multiple endocrine neoplastic syndrome type 1.

PhD J. Thomas Cunningham (University of Missouri-Columbia School of Medicine Dept. of Physiology); PhD Ronald H. Freeman (University of Missouri-Columbia School of Medicine Dept. of Physiology); Dr. Michael C. Hosokawa (University of Missouri-Columbia School of Medicine Dept. of Family and Community Medicine)

2001-12-01

177

Recombination of radical pairs in high magnetic fields: A path integral-Monte Carlo treatment  

Microsoft Academic Search

The magnetic field dependence of photoinduced geminate hydrogen (electron) transfer processes originates from a Brownian motion of radical pairs, a hyperfine coupling, and Zeeman-induced precession of the unpaired electron spins and a spin-selective recombination. In this paper we introduce a Wiener path integral description for these processes. This approach entails an integration over all possible diffusion trajectories of two functionals,

Klaus Schulten; Irving R. Epstein

1979-01-01

178

Integrated Tiger Series of electron/photon Monte Carlo transport codes: a user's guide for use on IBM mainframes  

SciTech Connect

The ITS (Integrated Tiger Series) Monte Carlo code package developed at Sandia National Laboratories and distributed as CCC-467/ITS by the Radiation Shielding Information Center (RSIC) at Oak Ridge National Laboratory (ORNL) consists of eight codes - the standard codes, TIGER, CYLTRAN, ACCEPT; the P-codes, TIGERP, CYLTRANP, ACCEPTP; and the M-codes ACCEPTM, CYLTRANM. The codes have been adapted to run on the IBM 3081, VAX 11/780, CDC-7600, and Cray 1 with the use of the update emulator UPEML. This manual should serve as a guide to a user running the codes on IBM computers having 370 architecture. The cases listed were tested on the IBM 3033, under the MVS operating system using the VS Fortran Level 1.3.1 compiler.

Kirk, B.L.

1985-12-01

179

Superfluid response of 4HeN-N2O clusters probed by path integral Monte Carlo simulations  

NASA Astrophysics Data System (ADS)

Using an improved path integral Monte Carlo method, finite-temperature structural and dynamical properties of 4HeN-N2O clusters (N ? 40) are investigated. The simulations employed a newly developed He-N2O interaction potential obtained at the CCSD(T) level. Good agreement with experimental observations was obtained for the evolution of the effective rotational constant as a function of cluster size. In particular, the experimentally observed turnaround at N = 6 for the effective rotational constant Beff is attributed to filling of the "donut" ring structure around the equator of the linear impurity molecule, and a second extremum in Beff for cluster sizes near N = 10 is associated with the emergence of superfluidity of the quantum solvent. A careful comparison with properties of HeN-CO2 clusters suggests that the difference between the renormalized rotational constants of the two impurity molecules is due to the anisotropy of the solute-solvent interaction potential.

Wang, Lecheng; Xie, Daiqian; Guo, Hua; Li, Hui; Le Roy, Robert J.; Roy, Pierre-Nicholas

2011-05-01

180

Error analysis of tissue optical properties determined by double-integrating sphere system and inverse Monte Carlo method  

NASA Astrophysics Data System (ADS)

To estimate the error of scattering coefficient spectrum determined by using double-integrating sphere system and inverse Monte Carlo method, optical properties of tissue phantom were measured. The tissue phantom was composed of hemoglobin, intralipid and gelatin. The thickness of samples (0.1-1.0 mm) and hemoglobin concentration (0.5-4.0 mg/ml) were changed and the effects of optical properties spectra were investigated. As the results, when the value of ?a was large, ?'s spectrum was not consistent with scattering theory. The higher hemoglobin concentration of samples was the lager the errors of ?'s spectra were. The thinner the sample was, the smaller the errors were. However ?a spectrum was not accurate when the sample was thin. It was predicted that when the sample thickness was 0.1 mm ?'s spectrum was accurate. And when the sample thickness was 1.0 mm, ?a spectrum was accurate.

Terada, Takaya; Nanjo, Takuya; Honda, Norihiro; Ishii, Katsunori; Awazu, Kunio

2011-02-01

181

Path-integral Monte Carlo simulations for interacting few-electron quantum dots with spin-orbit coupling  

NASA Astrophysics Data System (ADS)

We develop path-integral Monte Carlo simulations for a parabolic two-dimensional (2D) quantum dot containing N interacting electrons in the presence of Dresselhaus and/or Rashba spin-orbit couplings. Our method solves in a natural way the spin contamination problem and allows for numerically exact finite-temperature results at weak spin-orbit coupling. For N<10 electrons, we present data for the addition energy, the particle density, and the total spin S in the Wigner molecule regime of strong Coulomb interactions. We identify magic numbers at N=3 and N=7 via a peak in the addition energy. These magic numbers differ both from weak interaction and classical predictions, and are stable with respect to (weak) spin-orbit couplings.

Weiss, Stephan; Egger, R.

2005-12-01

182

Dynamics of the carbon nuclei in C{sub 60} studied by Feynman path-integral quantum Monte Carlo simulations  

SciTech Connect

The dynamics of the carbon nuclei in the C{sub 60} molecule have been studied by the Feynman path-integral (PI) quantum Monte Carlo (QMC) simulations and within a harmonic oscillator approximation. The following finite-temperature properties have been calculated: kinetic, potential, and total energy, radial and angular distribution functions (rdf, adf) as well as parameters describing the degree of atomic de/localization. The possible influence of quantum fluctuations on microscopic electronic structure properties of superconducting fullerides is briefly mentioned. PI simulations as well as simple analytical results show that the spatial uncertainty of the C atoms in C{sub 60} is comparable to the difference between the lengths of the short and long CC bonds in the icosahedral molecule. Reliable agreement between PI-derived rdf and the experimental curve based on neutron diffraction data is observed. 50 refs., 8 figs.

Boehm, M.C. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin (Germany); Ramirez, R. [Instituto de Ciencia de Materiales, Madrid (Spain)

1995-08-17

183

Reaction microtextures of REE Y Th U accessory minerals in the Monte Capanne pluton (Elba Island, Italy): a possible indicator of hybridization processes  

NASA Astrophysics Data System (ADS)

The study of accessory minerals in granitoid rocks can provide clues to the history of magmatic processes. In particular, the textural chemical characteristics of accessories could represent effective markers of hybridization processes. The concomitant occurrence of contrasting reaction microtextures of REE Y Th U accessory minerals in the Monte Capanne anatectic hybrid pluton suggests the occurrence of transient chemical conditions (alumina saturation up and down in the same system) in the early stages of crystallization. Incongruent dissolution of apatite produced microcrystal clusters of huttonitic monazite, while monazite-(Ce) crystals were replaced by allanite-(Ce)±apatite assemblage at the same location. A magma mingling process, involving acidic peraluminous and mafic metaluminous end-members, can provide the expected initial strong differences in alumina saturation that are able to induce such contrasting reactions. The proposed double exchange of accessory minerals between the two magmas strongly suggests a dynamic setting (stirring and straining of crystal-rich melts) in which anatectic and hybridization processes evolved.

Dini, A.; Rocchi, S.; Westerman, D. S.

2004-10-01

184

Feynman-Hibbs potentials and path integrals for quantum Lennard-Jones systems: Theory and Monte Carlo simulations  

NASA Astrophysics Data System (ADS)

This paper addresses unexplored aspects of the Feynman-Hibbs Gaussian picture and the ?2- and ?4-effective potentials obtainable from that model. Thermodynamic and structural properties are compared with their path-integral counterparts. In particular, a closed formula for the self-correlation (intranecklace) radial distribution function is derived from the Feynman-Hibbs model in view of, first, its importance in determining quantum structure factors and, second, the great difficulty in computing it accurately via path-integral calculations. In order to assess the reliability of the ?2- and ?4-potentials, neon liquid and helium-4 gas are studied for new state points with the corresponding semiclassical and 'exact' path-integral Monte Carlo simulations. As regards thermodynamics, energies, pressures and also specific heats at constant volume are reported. Structural results cover necklace radii of gyration, and instantaneous, linear response and self-correlation radial distribution functions. Comparison with experiment is made wherever possible, and the results indicate better performances for the ?2-potential.

Sesé, Luis M.

185

Fundamental Study of Hybrid Wind Tunnel Integrating Numerical Simulation and Experiment in Analysis of Flow Field  

NASA Astrophysics Data System (ADS)

This paper deals with a new flow analysis system, namely the hybrid wind tunnel, which integrates the experimental measurement with a wind tunnel and a corresponding numerical simulation with a computer. Analysis here is performed for the fundamental flow with the Karman vortex street in a wake of a square cylinder. A specific feature of the hybrid wind tunnel is existence of the feedback signal to compensate the error in the pressure on the side walls of the cylinder and the feed-forward signal to adjust the upstream velocity boundary condition. Investigation is focused on evaluating the hybrid wind tunnel as a flow analysis methodology with respect to the ordinary simulation and the experiment. As compared with the ordinary simulation, the hybrid wind tunnel substantially improves the accuracy and the efficiency in the analysis of the flow. Especially, the oscillation of the flow due to the Karman vortex street reproduced with the hybrid wind tunnel exactly synchronizes with that of the experiment, while that with the ordinary simulation never behave like that. In comparison with the experiment, the hybrid wind tunnel provides more detailed information of the flow than the experiment does.

Nisugi, Keisuke; Hayase, Toshiyuki; Shirai, Atsushi

186

Integrated Plasma Simulation of Lower Hybrid Current Drive in Tokamaks  

NASA Astrophysics Data System (ADS)

It has been shown in Alcator C-Mod that the onset time for sawteeth can be delayed significantly (up to 0.5 s) relative to ohmically heated plasmas, through the injection of off-axis LH current drive power [1]. We are simulating these experiments using the Integrated Plasma Simulator (IPS) [2], where the driven LH current density profiles are computed using a ray tracing component (GENRAY) and Fokker Planck code (CQL3D) [3] that are run in a tightly coupled time advance. The background plasma is evolved using the TSC transport code with the Porcelli sawtooth model [4]. Predictions of the driven LH current profiles will be compared with simpler ``reduced'' models for LHCD such as the LSC code which is implemented in TSC and which is also invoked within the IPS. [4pt] [1] C. E. Kessel et al, Bull. of the Am. Phys. Soc. 53, Poster PP6.00074 (2008). [0pt] [2] D. Batchelor et al, Journal of Physics: Conf. Series 125, 012039 (2008). [0pt] [3] R. W. Harvey and M. G. McCoy, Proc. of the IAEA Tech. Comm. Meeting on Simulation and Modeling of Therm. Plasmas, Montreal, Canada (1992). [0pt] [4] S. C. Jardin et al, J. Comp. Phys. 66, 481 (1986).

Bonoli, P. T.; Wright, J. C.; Harvey, R. W.; Batchelor, D. B.; Berry, L. A.; Kessel, C. E.; Jardin, S. C.

2012-03-01

187

A Programmable MicroFluidic Processor: Integrated and Hybrid Solutions  

SciTech Connect

The Programmable Fluidic Processor (PFP), a device conceived of by researchers at MD Anderson Cancer Center, is a reconfigurable and programmable bio-chemical analysis system designed for handheld operation in a variety of applications. Unlike most microfluidic systems which utilize channels to control fluids, the PFP device is a droplet-based system. The device is based on dielectrophoresis; a fluid transport phenomenon that utilizes mismatched polarizability between a droplet and its medium to induce droplet mobility. In the device, sample carrying droplets are polarized by an array of electrodes, individually addressable by subsurface microelectronics. My research focused on the development of a polymer-based microfluidic injection system for injecting these droplets onto the electrode array. The first of two device generations fabricated at LLNL was designed using extensive research and modeling performed by MD Anderson and Coventor. Fabricating the first generation required several iterations and design changes in order to generate an acceptable device for testing. Difficulties in planar fabrication of the fluidic system and a narrow channel design necessitated these changes. The second generation device incorporated modifications of the previous generation and improved on deficiencies discovered during experimentation with the initial device. Extensive modeling of the injection channels and fluid storage chamber also aided in redesigning the device's microfluidic system. A micromolding technique with interlocking features enabled precise alignments and dimensional control, critical requirements for device optimization. Fabrication of a final device will be fully integrated with the polymer-based microfluidics bonded directly to the silicon-based microelectronics. The optimized design and process flow developed in the trial generations will readily transfer to this approach.

Rose, K A

2002-05-10

188

Full Wave Simulation of Integrated Circuits Using Hybrid Numerical Methods  

NASA Astrophysics Data System (ADS)

Transmission lines play an important role in digital electronics, and in microwave and millimeter-wave circuits. Analysis, modeling, and design of transmission lines are critical to the development of the circuitry in the chip, subsystem, and system levels. In the past several decays, at the EM modeling level, the quasi-static approximation has been widely used due to its great simplicity. As the clock rates increase, the inter-connect effects such as signal delay, distortion, dispersion, reflection, and crosstalk, limit the performance of microwave systems. Meanwhile, the quasi-static approach loses its validity for some complex system structures. Since the successful system design of the PCB, MCM, and the chip packaging, rely very much on the computer aided EM level modeling and simulation, many new methods have been developed, such as the full wave approach, to guarantee the successful design. Many difficulties exist in the rigorous EM level analysis. Some of these include the difficulties in describing the behavior of the conductors with finite thickness and finite conductivity, the field singularity, and the arbitrary multilayered multi-transmission lines structures. This dissertation concentrates on the full wave study of the multi-conductor transmission lines with finite conductivity and finite thickness buried in an arbitrary lossy multilayered environment. Two general approaches have been developed. The first one is the integral equation method in which the dyadic Green's function for arbitrary layered media has been correctly formulated and has been tested both analytically and numerically. By applying this method, the double layered high dielectric permitivitty problem and the heavy dielectrical lossy problem in multilayered media in the CMOS circuit design have been solved. The second approach is the edge element method. In this study, the correct functional for the two dimensional propagation problem has been successfully constructed in a rigorous way from the vector wave equation at the first time. Applying this functional, the 2D1over2 propagation structures, including the dielectric loss, conductor loss, finite thickness of the conductors, and anisotropic dielectric material, are all solved in a consistent manner. Furthermore, the stripline-like open structures are solved by a newly proposed third kind of boundary conditions in the edge element implementation. By applying the new boundary condition to the open sides of the structures, the geometry mesh size is dramatically reduced and the CPU time is also saved greatly. The 2D1over2 structure study provides the basis for solving general 3D problems, including the transmission line discontinuities. This dissertation also studies many important issues including resonance problems and radiation effects. A design rule to avoid the spurious radiation is also suggested.

Tan, Jilin

189

Study of the Feynman-Hibbs effective potential against the path-integral formalism for Monte Carlo simulations of quantum many-body Lennard-Jones systems  

NASA Astrophysics Data System (ADS)

Approximate quantum pair radial correlation functions and thermodynamic quantities for Lennard-Jones systems can be computed with Monte Carlo simulation involving Feynman-Hibbs potentials. A convolution approach to produce the quantum pair radial function from the direct Monte Carlo structural results is presented by analysing its connection with the path-integral instantaneous and linear response pair radial functions. Several Lennard-Jones systems with substantial quantum behaviour: methane, argon, neon, deuterium and helium-4 (eighteen state points) are studied. For the sake of comparison, new path-integral simulations of helium-4 and improved path-integral results for methane are also reported. The effective potential results are in close agreement with experimental and exact path-integral data over a wide range of de Broglie wavelengths, densities and temperatures.

Sesé, Luis M.

190

ITS Version 6 : the integrated TIGER series of coupled electron/photon Monte Carlo transport codes.  

SciTech Connect

ITS is a powerful and user-friendly software package permitting state-of-the-art Monte Carlo solution of lineartime-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 6, the latest version of ITS, contains (1) improvements to the ITS 5.0 codes, and (2) conversion to Fortran 90. The general user friendliness of the software has been enhanced through memory allocation to reduce the need for users to modify and recompile the code.

Franke, Brian Claude; Kensek, Ronald Patrick; Laub, Thomas William

2008-04-01

191

Monte Carlo ray-tracing simulations of luminescent solar concentrators for building integrated photovoltaics  

NASA Astrophysics Data System (ADS)

Luminescent solar concentrators (LSCs) have the ability to receive light from a wide range of angles, concentrating the captured light onto small photo active areas. This enables greater incorporation of LSCs into building designs as windows, skylights and wall claddings in addition to rooftop installations of current solar panels. Using relatively cheap luminescent dyes and acrylic waveguides to effect light concentration onto lesser photovoltaic (PV) cells, there is potential for this technology to approach grid price parity. We employ a panel design in which the front facing PV cells collect both direct and concentrated light ensuring a gain factor greater than one. This also allows for flexibility in determining the placement and percentage coverage of PV cells during the design process to balance reabsorption losses against the power output and level of light concentration desired. To aid in design optimization, a Monte-Carlo ray tracing program was developed to study the transport of photons and loss mechanisms in LSC panels. The program imports measured absorption/emission spectra and transmission coefficients as simulation parameters with interactions of photons in the panel determined by comparing calculated probabilities with random number generators. LSC panels with multiple dyes or layers can also be simulated. Analysis of the results reveals optimal panel dimensions and PV cell layouts for maximum power output for a given dye concentration, absorbtion/emission spectrum and quantum efficiency.

Leow, Shin Woei; Corrado, Carley; Osborn, Melissa; Carter, Sue A.

2013-09-01

192

Backscatter towards the monitor ion chamber in high-energy photon and electron beams: charge integration versus Monte Carlo simulation  

NASA Astrophysics Data System (ADS)

In some linear accelerators, the charge collected by the monitor ion chamber is partly caused by backscattered particles from accelerator components downstream from the chamber. This influences the output of the accelerator and also has to be taken into account when output factors are derived from Monte Carlo simulations. In this work, the contribution of backscattered particles to the monitor ion chamber response of a Varian 2100C linac was determined for photon beams (6, 10 MV) and for electron beams (6, 12, 20 MeV). The experimental procedure consisted of charge integration from the target in a photon beam or from the monitor ion chamber in electron beams. The Monte Carlo code EGS4/BEAM was used to study the contribution of backscattered particles to the dose deposited in the monitor ion chamber. Both measurements and simulations showed a linear increase in backscatter fraction with decreasing field size for photon and electron beams. For 6 MV and 10 MV photon beams, a 2-3% increase in backscatter was obtained for a 0.5×0.5 cm2 field compared to a 40×40 cm2 field. The results for the 6 MV beam were slightly higher than for the 10 MV beam. For electron beams (6, 12, 20 MeV), an increase of similar magnitude was obtained from measurements and simulations for 6 MeV electrons. For higher energy electron beams a smaller increase in backscatter fraction was found. The problem is of less importance for electron beams since large variations of field size for a single electron energy usually do not occur.

Verhaegen, F.; Symonds-Tayler, R.; Liu, H. H.; Nahum, A. E.

2000-11-01

193

Integrated magnetobiostratigraphy, paleoclimatic and paleoceanographic inferences of the middle Eocene-Oligocene interval from the Monte Cagnero Section, central Italy  

NASA Astrophysics Data System (ADS)

The early Eocene to early Oligocene (~55 to 28 Ma) was an important time period for Cenozoic paleoclimatic and paleogeographic evolution. Deep-sea foraminiferal stable isotope records (?18O and ?13C) indicate a long-term cooling trend that culminated in the Oi-1 glaciation near the Eocene/Oligocene transition at ~34 Ma. In the middle to late Eocene (~49 to 34 Ma), these records also indicate a strong, transient warming event (Middle Eocene Climate Optimum - MECO) at ~40 Ma. The Monte Cagnero sedimentary section, located in the northeastern Apennines near Urbania, Italy, in the Umbria-Marche Basin, is an important middle Eocene-Oligocene section. We use magneto-biostratigraphy and environmental magnetism to study the impact of closure of the Neo-Tethyan gateway on subtropical Eocene circulation to better understand global climate changes during the switch from greenhouse to icehouse conditions. The studied sediments consist of alternating reddish and greenish limestones and marlstones. We undertook high-resolution (~5 cm sample intervals) paleomagnetic and foraminiferal biostratigraphic analyses to construct an integrated age model. The magnetic mineralogy is dominated by a mixture of high- and low-coercivity minerals (probably hematite and magnetite). Environmental magnetic data indicate long-term trends in the concentration, grain-size and composition of magnetic minerals. Moreover, we recognize a magnetic signature that may be related to the MECO event. These new bio-, chemo-, and magnetic results from Monte Cagnero suggest that the section provides a continuous and well-preserved interval for analyzing middle Eocene to lower Oligocene climate. Ongoing analyses are aimed at unraveling paleoclimatic and paleoceanographic changes during a time interval that is not well recorded at other localities.

Jovane, L.; Savian, J. F.; Bohaty, S. M.; Wilson, P. A.; Coccioni, R.; Frontalini, F.; Bancala, G.; Luciani, V.; Roberts, A.

2010-12-01

194

Advanced hybrid integrated low-power telemetric pressure monitoring system for biomedical applications  

Microsoft Academic Search

A new, highly miniaturized hybrid integrated solution for telemetric pressure measurement in biomedical applications is presented. The telemetrically powered ITES (Implantable Telemetric Endo-System) consists of a surface micro-machined capacitive type absolute pressure sensor fabricated in an eight-mask MOS-like process and two low-power ASICs for capacitance change read-out and telemetric data and energy transmission. An advanced flip-chip mounting and assembly technology

T. Eggers; C. Marschner; U. Marschner; B. Clasbrummel; R. Laur; J. Binder

2000-01-01

195

Towards an Expansive Hybrid Psychology: Integrating Theories of the Mediated Mind  

Microsoft Academic Search

This article develops an integrative theory of the mind by examining how the mind, understood as a set of skills and dispositions,\\u000a depends upon four sources of mediators. Harré’s hybrid psychology is taken as a meta-theoretical starting point, but is expanded\\u000a significantly by including the four sources of mediators that are the brain, the body, social practices and technological\\u000a artefacts.

Svend Brinkmann

2011-01-01

196

Control strategies of a fuel-cell hybrid tramway integrating two dc\\/dc converters  

Microsoft Academic Search

This paper compares two control strategies of a fuel cell (FC)-battery powered hybrid system integrating two dc\\/dc converters for the Metro-Centro tramway (400 kW) from Seville, Spain. Besides, modeling of each component is briefly presented. These models have been implemented in MATLAB\\/SIMULINK environment. A Polymer Electrolyte Membrane (PEM) FC is used in this work. The FC model characteristics are selected

L. M. Fernandez; C. A. Garcia; P. Garcia; J. P. Torreglosa; F. Jurado

2010-01-01

197

An integrated hybrid system for genetic analysis combining EWOD sample preparation and magnetic detection  

NASA Astrophysics Data System (ADS)

Over the last decade microelectronic technologies have delivered significant advances in devices for point of care diagnostics. Complex microfluidic systems integrate components such as valves, pumps etc. to manipulate liquids. In recent years, the drive is to combine biochemical protocols in a single system, delivering "sample in answer out". An Electrowetting on Dielectric (EWOD) device offers the possibility to move and manipulate 64nl volumes implementing biochemical processes, while the magnetic sensor facilitates hybridisation detection. We outline an injection molding approach where EWOD and magnetic devices are integrated into a hybrid microfluidic system with the potential to implement "sample in answer out" biological protocols.

Brennan, Des; Jary, Dorothee; Peponnet, Christine; Cardosa, Filipe; Freitas, Paolo; Dinca, Mihai; Aherne, Margaret; Galvin, Paul

2011-08-01

198

Hybrid Modeling of a Capacitively Coupled Radio Frequency Glow Discharge in Argon: Combined Monte Carlo and Fluid Model  

Microsoft Academic Search

A hybrid model has been developed for a capacitively coupled rf glow discharge in argon, employed as a spectroscopic source in the field of analytical chemistry. The cell is a rather small cylinder with a very small rf-powered electrode (only 5 mm in diameter). The typical working conditions applied for analytical spectroscopy are a gas pressure of 6 Torr and

Annemie Bogaerts; Renaat Gijbels; WimGoedheer WimGoedheer

1999-01-01

199

Hybrid integrated photodetector with flat-top steep-edge spectral response.  

PubMed

Hybrid integrated photodetectors with flat-top steep-edge spectral responses that consist of an Si-based multicavity Fabry-Perot (F-P) filter and an InP-based p-i-n absorption structure (with a 0.2 ?m In(0.53)Ga(0.47)As absorption layer), have been designed and fabricated. The performance of the hybrid integrated photodetectors is theoretically investigated by including key factors such as the thickness of each cavity, the pairs of each reflecting mirror, and the thickness of the benzocyclobutene bonding layer. The device is fabricated by bonding an Si-based multicavity F-P filter with an InP-based p-i-n absorption structure. A hybrid integrated photodetector with a peak quantum efficiency of 55% around 1549.2 nm, the -0.5 dB band of 0.43 nm, the 25 dB band of 1.06 nm, and 3 dB bandwidth more than 16 GHz, is simultaneously obtained. Based on multicavity F-P structure, this device has good flat-top steep-edge spectral response. PMID:22907001

Fan, Xinye; Huang, Yongqing; Ren, Xiaomin; Duan, Xiaofeng; Hu, Fuquan; Wang, Qi; Cai, Shiwei; Zhang, Xia

2012-08-20

200

A novel hybridization of higher order finite element and boundary integral methods for electromagnetic scattering and radiation problems  

Microsoft Academic Search

A novel hybridization of the finite element (FE) and boundary integral methods is presented for an efficient and accurate numerical analysis of electromagnetic scattering and radiation problems. The proposed method derives an adaptive numerical absorbing boundary condition (ABC) for the finite element solution based on boundary integral equations. Unlike the standard finite element-boundary integral approach, the proposed method is free

Jian Liu; Jian-Ming Jin

2001-01-01

201

A hybrid multiscale Monte Carlo algorithm (HyMSMC) to cope with disparity in time scales and species populations in intracellular networks  

PubMed Central

Background The fundamental role that intrinsic stochasticity plays in cellular functions has been shown via numerous computational and experimental studies. In the face of such evidence, it is important that intracellular networks are simulated with stochastic algorithms that can capture molecular fluctuations. However, separation of time scales and disparity in species population, two common features of intracellular networks, make stochastic simulation of such networks computationally prohibitive. While recent work has addressed each of these challenges separately, a generic algorithm that can simultaneously tackle disparity in time scales and population scales in stochastic systems is currently lacking. In this paper, we propose the hybrid, multiscale Monte Carlo (HyMSMC) method that fills in this void. Results The proposed HyMSMC method blends stochastic singular perturbation concepts, to deal with potential stiffness, with a hybrid of exact and coarse-grained stochastic algorithms, to cope with separation in population sizes. In addition, we introduce the computational singular perturbation (CSP) method as a means of systematically partitioning fast and slow networks and computing relaxation times for convergence. We also propose a new criteria of convergence of fast networks to stochastic low-dimensional manifolds, which further accelerates the algorithm. Conclusion We use several prototype and biological examples, including a gene expression model displaying bistability, to demonstrate the efficiency, accuracy and applicability of the HyMSMC method. Bistable models serve as stringent tests for the success of multiscale MC methods and illustrate limitations of some literature methods.

Samant, Asawari; Ogunnaike, Babatunde A; Vlachos, Dionisios G

2007-01-01

202

Sampling function of single-X-ray-photon counting hybrid pixel detectors: combining an analytical approach to Monte-Carlo simulations and Finite-Element-Modeling  

NASA Astrophysics Data System (ADS)

Spectroscopic and imaging performance parameters of hybrid pixel detectors operated in single-X-ray photon-counting mode can be inferred from the dependence of their sampling function (or aperture function) on the detection energy threshold. In a previous paper, it was shown that this dependence could be modelled using a simple analytical method. Measurements were performed on typical synchrotron X-ray detectors and fitted to the analytical formulas in order to obtain detector parameters such as charge-sharing width, energy dispersion and fill-factor at 50% threshold. In the present paper, we use Monte-Carlo (MC) and Finite-Element-Modeling (FEM) software tools to perform a more detailed simulation of image formation processes taking place in photon-counting hybrid pixel detectors of various pixel sizes associated to standard silicon sensor thickness and exposed to 15 keV monochromatic X-rays. We show that the MC/FEM simulation results can be used to produce detector parameters required in the analytical expressions of the sampling function of these detectors.

McGrath, J.; Marchal, J.; Medjoubi, K.

2013-10-01

203

hybrid\\scriptsize{{MANTIS}}: a CPU-GPU Monte Carlo method for modeling indirect x-ray detectors with columnar scintillators  

NASA Astrophysics Data System (ADS)

The computational modeling of medical imaging systems often requires obtaining a large number of simulated images with low statistical uncertainty which translates into prohibitive computing times. We describe a novel hybrid approach for Monte Carlo simulations that maximizes utilization of CPUs and GPUs in modern workstations. We apply the method to the modeling of indirect x-ray detectors using a new and improved version of the code \\scriptsize{{MANTIS}}, an open source software tool used for the Monte Carlo simulations of indirect x-ray imagers. We first describe a GPU implementation of the physics and geometry models in fast\\scriptsize{{DETECT}}2 (the optical transport model) and a serial CPU version of the same code. We discuss its new features like on-the-fly column geometry and columnar crosstalk in relation to the \\scriptsize{{MANTIS}} code, and point out areas where our model provides more flexibility for the modeling of realistic columnar structures in large area detectors. Second, we modify \\scriptsize{{PENELOPE}} (the open source software package that handles the x-ray and electron transport in \\scriptsize{{MANTIS}}) to allow direct output of location and energy deposited during x-ray and electron interactions occurring within the scintillator. This information is then handled by optical transport routines in fast\\scriptsize{{DETECT}}2. A load balancer dynamically allocates optical transport showers to the GPU and CPU computing cores. Our hybrid\\scriptsize{{MANTIS}} approach achieves a significant speed-up factor of 627 when compared to \\scriptsize{{MANTIS}} and of 35 when compared to the same code running only in a CPU instead of a GPU. Using hybrid\\scriptsize{{MANTIS}}, we successfully hide hours of optical transport time by running it in parallel with the x-ray and electron transport, thus shifting the computational bottleneck from optical to x-ray transport. The new code requires much less memory than \\scriptsize{{MANTIS}} and, as a result, allows us to efficiently simulate large area detectors.

Sharma, Diksha; Badal, Andreu; Badano, Aldo

2012-04-01

204

Los Alamos hybrid environment: an integrated development/configuration management system  

SciTech Connect

I present the details of a hybrid configuration management system that utilizes a commercial configuration management tool (Softool's Change and Configuration Control environment) to monitor and control the development of mission-critical software systems at the Los Alamos Weapons Neutron Research Facility. The hybrid system combines features of the VMS host operating system and elements of the tool environment to integrate a flexible development environment with a very powerful automated configuration management system. The features of this system are presented with particular emphasis on the benefits of the hybrid approach. The complementary nature of the constituent environments is described. Special attention is given the issues of operational tradeoffs, personnel interaction and utilization, management visibility and overall system performance. It is shown that by employing a special interface data structure, the hybrid environment supports a much higher level of automation (of both development and configuration management activities) than is realizable in either environment individually. Examples are provided to illustrate the extent to which development activities and all phases of configuration management can be automated under this system. It is shown that in the process of providing a rigorous configuration management environment, the system remains virtually transparent to software development personnel and actually enhances the programmer's capabilities.

Cort, G.

1984-01-01

205

Finite temperature path integral Monte Carlo simulations of structural and dynamical properties of ArN-CO2 clusters  

NASA Astrophysics Data System (ADS)

We report finite temperature quantum mechanical simulations of structural and dynamical properties of ArN-CO2 clusters using a path integral Monte Carlo algorithm. The simulations are based on a newly developed analytical Ar-CO2 interaction potential obtained by fitting ab initio results to an anisotropic two-dimensional Morse/Long-range function. The calculated distributions of argon atoms around the CO2 molecule in ArN-CO2 clusters with different sizes are consistent to the previous studies of the configurations of the clusters. A first-order perturbation theory is used to quantitatively predict the CO2 vibrational frequency shift in different clusters. The first-solvation shell is completed at N = 17. Interestingly, our simulations for larger ArN-CO2 clusters showed several different structures of the argon shell around the doped CO2 molecule. The observed two distinct peaks (2338.8 and 2344.5 cm-1) in the ?3 band of CO2 may be due to the different arrangements of argon atoms around the dopant molecule.

Wang, Lecheng; Xie, Daiqian

2012-08-01

206

Extrapolation to infinite Trotter number in path-integral Monte Carlo simulations of solid-state systems  

NASA Astrophysics Data System (ADS)

We consider the problem of the extrapolation of path-integral Monte Carlo (PIMC) data to infinite Trotter number P. Finite-P data, being even functions of P, have high-P dependence that is generally well described by a quadratic fit, a0+a1P-2, where a0 is the exact quantum value. However, in order to get convergence it is often necessary to run PIMC codes with rather high P values, which implies long computer times and larger statistical errors of the data. It is well known that also for harmonic systems the finite-P data are not exact; nevertheless, they can be easily calculated by Gaussian quadrature. Starting from this observation, we suggest an easy way to correct PIMC data for anharmonic systems in order to take into account the harmonic part exactly, with strong improvement of the extrapolation to P=?. Lower Trotter numbers are thus required, with the advantages of computer-time saving and much better accuracy of the extrapolated values, without any change in the PIMC code. In order to demonstrate the effectiveness of the approach, we report finite-P data processing for a single anharmonic particle, whose finite-P data are obtained by the matrix-squaring method, and for a chain of atoms with Morse interaction.

Cuccoli, Alessandro; Macchi, Alessandro; Pedrolli, Gaia; Tognetti, Valerio; Vaia, Ruggero

1995-05-01

207

Monte Carlo Simulations of Luminescent Solar Concentrators with Front-Facing Photovoltaic Cells for Building Integrated Photovoltaics  

NASA Astrophysics Data System (ADS)

Luminescent solar concentrators (LSCs) have the ability to receive light from a wide range of angles and concentrate the captured light on to small photo active areas. This enables LSCs to be integrated more extensively into buildings as windows and wall claddings on top of roof installations. LSCs with front facing PV cells collect both direct and concentrated light ensuring a gain factor greater than one. It also allows for flexibility in determining the placement and percentage coverage of PV cells when designing panels to balance reabsorption losses, power output and the level of concentration desired. A Monte-Carlo ray tracing program was developed to study the transport of photons and loss mechanisms in LSC panels and aid in design optimization. The program imports measured absorption/emission spectra and transmission coefficients as simulation parameters. Interactions of photons with the LSC panel are determined by comparing calculated probabilities with random number generators. Simulation results reveal optimal panel dimensions and PV cell layouts to achieve maximum power output.

Woei Leow, Shin; Corrado, Carley; Osborn, Melissa; Carter, Sue

2013-03-01

208

A microfluidic microprocessor: controlling biomimetic containers and cells using hybrid integrated circuit/microfluidic chips.  

PubMed

We present an integrated platform for performing biological and chemical experiments on a chip based on standard CMOS technology. We have developed a hybrid integrated circuit (IC)/microfluidic chip that can simultaneously control thousands of living cells and pL volumes of fluid, enabling a wide variety of chemical and biological tasks. Taking inspiration from cellular biology, phospholipid bilayer vesicles are used as robust picolitre containers for reagents on the chip. The hybrid chip can be programmed to trap, move, and porate individual living cells and vesicles and fuse and deform vesicles using electric fields. The IC spatially patterns electric fields in a microfluidic chamber using 128 × 256 (32,768) 11 × 11 ?m(2) metal pixels, each of which can be individually driven with a radio frequency (RF) voltage. The chip's basic functions can be combined in series to perform complex biological and chemical tasks and can be performed in parallel on the chip's many pixels for high-throughput operations. The hybrid chip operates in two distinct modes, defined by the frequency of the RF voltage applied to the pixels: Voltages at MHz frequencies are used to trap, move, and deform objects using dielectrophoresis and voltages at frequencies below 1 kHz are used for electroporation and electrofusion. This work represents an important step towards miniaturizing the complex chemical and biological experiments used for diagnostics and research onto automated and inexpensive chips. PMID:20835430

Issadore, David; Franke, Thomas; Brown, Keith A; Westervelt, Robert M

2010-09-08

209

Suppression of backreflection noise in a resonator integrated optic gyro by hybrid phase-modulation technology.  

PubMed

A method to suppress backreflection noise due to facet reflection in a resonator integrated optic gyro (RIOG) is demonstrated using hybrid phase-modulation technology (HPMT). First, calculations are carried out to evaluate the effect of the backreflection. Although its amplitude has been remarkably decreased by angle polishing, residual backreflection noise is still a severe factor in RIOGs. Next, a hybrid phase-modulation method to eliminate the backreflection noise is constructed, and the frequency spectra of the photodetector outputs before and after adopting HPMT are analyzed. Theoretical analysis shows that the backreflection noise spectra will split from each other as a result of the hybrid phase modulation. In association with the pectinate-filter characteristics of digital correlation detection, the backreflection noise can be suppressed. Finally, the RIOG experimental setup is established and compared with opposite-slope triangle phase-modulation technology. HPMT has the advantage of suppressing backreflection noise, with the RIOG bias stability greatly improved from 2.34 to 0.22 deg/s (10 s integration time). PMID:23478771

Feng, Lishuang; Lei, Ming; Liu, Huilan; Zhi, Yinzhou; Wang, Junjie

2013-03-10

210

Hybrid integration of Fabry-Pérot cavity with waveguide photodetector on silicon substrate  

NASA Astrophysics Data System (ADS)

This paper demonstrated a novel device which was fabricated by the integration of a Fabry-Pérot cavity with waveguide photodetectors on silicon substrate. The design of this device integrates two functions on a single semiconductor chip, which is a current trend to make the compact on-chip photonic system. Due to the introduction of waveguide photodetectors, the tradeoff between efficiency and bandwidth could be improved and these two important factors could be specified almost independently. The Fabry-Pérot cavity was grown by metal-organic chemical vapor deposition (MOCVD), which was used for wavelength selectivity. The waveguide photodetector fabricated by the wet etching technique was used for light detection. The peak wavelength of the hybrid integrated device was at 1538nm. The full-width at half-maximum was about 0.3nm, and a dark current of 3.2nA was achieved at the reverse bias of 3.0V.

Hu, Fuquan; Huang, Yongqing; Ren, Xiaomin; Duan, Xiaofeng; Zhang, Xu; Fan, Xinye; Wang, Wei; Shang, Yufeng; Cai, Shiwei

2013-06-01

211

Anharmonic effects on the structural and vibrational properties of the ethyl radical: A path integral Monte Carlo study  

NASA Astrophysics Data System (ADS)

The structural and vibrational properties of the ethyl radical have been investigated by a series of finite temperature simulations that treat the nuclei as quantum particles. The potential energy surface of the electronic ground state has been described by a nonorthogonal tight-binding Hamiltonian that provides results in reasonable agreement with ab initio methods. The quantum nature of the nuclei has been described by path integral Monte Carlo simulations at temperatures between 25 and 1000 K. Special interest deserves the determination of anharmonic and tunneling effects in the zero-point vibrational structure. In particular, we have studied the influence of anharmonic effects both on the mean value and the quantum fluctuations of equilibrium bond lengths and bond angles. The local structure of the radical center is found to be planar as a result of the zero-point motion of the atomic nuclei, even though the minimum energy configuration exhibits a pyramidal structure for this center. Anharmonic effects in the fundamental vibrational modes of the molecule are studied by a nonperturbative approach based on the centroid density. This function is a path integral concept that provides information on the static response of the system to applied external forces. Our study reveals a softening of the stretching modes associated with the C-H bonds and a hardening of the out-of-plane rocking motion of the methylene group. Both effects are in good agreement with experimental and ab initio data. The softening of the C-C stretching mode predicted by our simulations suggests a revision of the currently accepted experimental assignment for two fundamental vibrations of the ethyl radical. The tunneling of an H atom between the methyl and methylene groups has been investigated. These simulations should contribute to the open question whether or not this process is responsible for the changes in the electron spin resonance spectrum at low temperatures.

López-Ciudad, Telesforo; Ramírez, Rafael; Schulte, Joachim; Böhm, Michael C.

2003-08-01

212

A Hybrid Monte Carlo Method Based Artificial Neural Networks Approach for Rock Boundaries Identification: A Case Study from the KTB Bore Hole  

NASA Astrophysics Data System (ADS)

Identification of rock boundaries and structural features from well log response is a fundamental problem in geological field studies. However, in a complex geologic situation, such as in the presence of crystalline rocks where metamorphisms lead to facies changes, it is not easy to discern accurate information from well log data using conventional artificial neural network (ANN) methods. Moreover inferences drawn by such methods are also found to be ambiguous because of the strong overlapping of well log signals, which are generally tainted with deceptive noise. Here, we have developed an alternative ANN approach based on Bayesian statistics using the concept of Hybrid Monte Carlo (HMC)/Markov Chain Monte Carlo (MCMC) inversion scheme for modeling the German Continental Deep Drilling Program (KTB) well log data. MCMC algorithm draws an independent and identically distributed (i.i.d) sample by Markov Chain simulation technique from posterior probability distribution using the principle of statistical mechanics in Hamiltonian dynamics. In this algorithm, each trajectory is updated by approximating the Hamiltonian differential equations through a leapfrog discrimination scheme. We examined the stability and efficiency of the HMC-based approach on “noisy” data assorted with different levels of colored noise. We also perform uncertainty analysis by estimating standard deviation (STD) error map of a posteriori covariance matrix at the network output of three types of lithofacies over the entire length of the litho section of KTB. Our analyses demonstrate that the HMC-based approach renders robust means for classification of complex lithofacies successions from the KTB borehole noisy signals, and hence may provide a useful guide for understanding the crustal inhomogeneity and structural discontinuity in many other tectonically critical and complex regions.

Maiti, Saumen; Tiwari, R. K.

2009-11-01

213

Performance analysis of an OTEC plant and a desalination plant using an integrated hybrid cycle  

SciTech Connect

A performance analysis of an OTEC plant using an integrated hybrid cycle (I-H OTEC Cycle) has been conducted. The I-H OTEC cycle is a combination of a closed-cycle OTEC plant and a spray flash desalination plant. In an I-H OTEC cycle, warm sea water evaporates the liquid ammonia in the OTEC evaporator, then enters the flash chamber and evaporates itself. The evaporated steam enters the desalination condenser and is condensed by the cold sea water passed through the OTEC condenser. The optimization of the I-H OTEC cycle is analyzed by the method of steepest descent. The total heat transfer area of heat exchangers per net power is used as an objective function. Numerical results are reported for a 10 MW I-H OTEC cycle with plate-type heat exchangers and ammonia as working fluid. The results are compared with those of a joint hybrid OTEC cycle (J-H OTEC Cycle).

Uehara, Haruo; Miyara, Akio; Ikegami, Yasuyuki [Saga Univ. (Japan); Nakaoka, Tsutomu [National Fisheries Univ., Simonoseki, Yamaguchi (Japan). Dept. of Marine Engineering

1996-05-01

214

Hybrid III/V silicon photonic source with integrated 1D free-space beam steering.  

PubMed

A chip-scale optical source with integrated beam steering is demonstrated. The chip was fabricated using the hybrid silicon platform and incorporates an on-chip laser, waveguide splitter, amplifiers, phase modulators, and surface gratings to comprise an optical phased array with beam steering across a 12° field of view in one axis. Tuning of the phased array is used to achieve 1.8°(steered axis)×0.6°(nonsteered axis) beam width with 7 dB background suppression for arbitrary beam direction within the field of view. PMID:23073429

Doylend, J K; Heck, M J R; Bovington, J T; Peters, J D; Davenport, M L; Coldren, L A; Bowers, J E

2012-10-15

215

Integrated hybrid Si/InGaAs 50 Gb/s DQPSK receiver.  

PubMed

A monolithic 25 Gbaud DQPSK receiver based on delay interferometers and balanced detection has been designed and fabricated on the hybrid Si/InGaAs platform. The integrated 30 µm long InGaAs p-i-n photodetectors have a responsivity of 0.64 A/W at 1550 nm and a 3dB bandwidth higher than 25 GHz. The delay interferometer shows a delay time of 39.2 ps and an extinction ratio higher than 20 dB. The demodulation of a 25 Gb/s DPSK signal by a single branch of the receiver demonstrates its correct working principle. PMID:23037025

Faralli, Stefano; Nguyen, Kimchau N; Peters, Jonathan D; Spencer, Daryl T; Blumenthal, Daniel J; Bowers, John E

2012-08-27

216

Integrated planar terahertz resonators for femtomolar sensitivity label-free detection of DNA hybridization.  

PubMed

A promising label-free approach for the analysis of genetic material by means of detecting the hybridization of polynucleotides with electromagnetic waves at terahertz (THz) frequencies is presented. Using an integrated waveguide approach, incorporating resonant THz structures as sample carriers and transducers for the analysis of the DNA molecules, we achieve a sensitivity down to femtomolar levels. The approach is demonstrated with time-domain ultrafast techniques based on femtosecond laser pulses for generating and electro-optically detecting broadband THz signals, although the principle can certainly be transferred to other THz technologies. PMID:11936814

Nagel, Michael; Bolivar, Peter Haring; Brucherseifer, Martin; Kurz, Heinrich; Bosserhoff, Anja; Büttner, Reinhard

2002-04-01

217

Structural Heterogeneity and Quantitative FRET Efficiency Distributions of Polyprolines through a Hybrid Atomistic Simulation and Monte Carlo Approach  

PubMed Central

Förster Resonance Energy Transfer (FRET) experiments probe molecular distances via distance dependent energy transfer from an excited donor dye to an acceptor dye. Single molecule experiments not only probe average distances, but also distance distributions or even fluctuations, and thus provide a powerful tool to study biomolecular structure and dynamics. However, the measured energy transfer efficiency depends not only on the distance between the dyes, but also on their mutual orientation, which is typically inaccessible to experiments. Thus, assumptions on the orientation distributions and averages are usually made, limiting the accuracy of the distance distributions extracted from FRET experiments. Here, we demonstrate that by combining single molecule FRET experiments with the mutual dye orientation statistics obtained from Molecular Dynamics (MD) simulations, improved estimates of distances and distributions are obtained. From the simulated time-dependent mutual orientations, FRET efficiencies are calculated and the full statistics of individual photon absorption, energy transfer, and photon emission events is obtained from subsequent Monte Carlo (MC) simulations of the FRET kinetics. All recorded emission events are collected to bursts from which efficiency distributions are calculated in close resemblance to the actual FRET experiment, taking shot noise fully into account. Using polyproline chains with attached Alexa 488 and Alexa 594 dyes as a test system, we demonstrate the feasibility of this approach by direct comparison to experimental data. We identified cis-isomers and different static local environments as sources of the experimentally observed heterogeneity. Reconstructions of distance distributions from experimental data at different levels of theory demonstrate how the respective underlying assumptions and approximations affect the obtained accuracy. Our results show that dye fluctuations obtained from MD simulations, combined with MC single photon kinetics, provide a versatile tool to improve the accuracy of distance distributions that can be extracted from measured single molecule FRET efficiencies.

Hoefling, Martin; Lima, Nicola; Haenni, Dominik; Seidel, Claus A. M.; Schuler, Benjamin; Grubmuller, Helmut

2011-01-01

218

Hybrid extended particle filter (HEPF) for integrated inertial navigation and global positioning systems  

NASA Astrophysics Data System (ADS)

Navigation includes the integration of methodologies and systems for estimating time-varying position, velocity and attitude of moving objects. Navigation incorporating the integrated inertial navigation system (INS) and global positioning system (GPS) generally requires extensive evaluations of nonlinear equations involving double integration. Currently, integrated navigation systems are commonly implemented using the extended Kalman filter (EKF). The EKF assumes a linearized process, measurement models and Gaussian noise distributions. These assumptions are unrealistic for highly nonlinear systems like land vehicle navigation and may cause filter divergence. A particle filter (PF) is developed to enhance integrated INS/GPS system performance as it can easily deal with nonlinearity and non-Gaussian noises. In this paper, a hybrid extended particle filter (HEPF) is developed as an alternative to the well-known EKF to achieve better navigation data accuracy for low-cost microelectromechanical system sensors. The results show that the HEPF performs better than the EKF during GPS outages, especially when simulated outages are located in periods with high vehicle dynamics.

Aggarwal, Priyanka; Syed, Zainab; El-Sheimy, Naser

2009-05-01

219

The development of a power Darlington transistor and hybrid integrated circuit for a dc to dc converter  

Microsoft Academic Search

A power Darlington transistor Subscrete and hybrid integrated circuit consisting of two of these in parallel with a fast recovery diode are described. The integrated unit is used as a dc-to-dc converter or 'chopper' to control the acceleration and speed of an electric car motor and can deliver 450 A of armature current. The Subscrete form permits full testing and

S. Krishna; A. J. Yerman

1979-01-01

220

Hybrid PSO Based Integration of Multiple Representations of Thermal Hand Vein Patterns  

NASA Astrophysics Data System (ADS)

This paper outlines a novel personal authentication approach by integrating the multiple feature representations of thermal hand vein patterns. In the present work, vein patterns are regarded as comprising textures. Accordingly two types of texture features using Gabor wavelets and fuzzy logic are extracted from the acquired vein images. Since both the approaches have different domains of feature representation, their integration is accomplished at the decision level by incorporating individual decisions using the Euclidean distance based classifiers. The optimal decision parameters comprising individual decision thresholds and one fusion rule out of 16 rules for two features are estimated with the help of hybrid Particle Swarm Optimization (PSO) which can optimize the decisions taken by the individual classifiers. The experimental results carried out on 100 user database are promising thus confirming the usefulness of the proposed authentication system.

Kumar, Amioy; Hanmandlu, Madasu; Gupta, H. M.

221

Integration Issues of Cells into Battery Packs for Plug-in and Hybrid Electric Vehicles: Preprint  

SciTech Connect

The main barriers to increased market share of hybrid electric vehicles (HEVs) and commercialization of plug-in HEVs are the cost, safety, and life of lithium ion batteries. Significant effort is being directed to address these issues for lithium ion cells. However, even the best cells may not perform as well when integrated into packs for vehicles because of the environment in which vehicles operate. This paper discusses mechanical, electrical, and thermal integration issues and vehicle interface issues that could impact the cost, life, and safety of the system. It also compares the advantages and disadvantages of using many small cells versus a few large cells and using prismatic cells versus cylindrical cells.

Pesaran, A. A.; Kim, G. H.; Keyser, M.

2009-05-01

222

Integration of plug-in hybrid electric vehicles (PHEV) with grid connected residential photovoltaic energy systems  

NASA Astrophysics Data System (ADS)

This paper proposes an approach for integrating Plug-In Hybrid Electric Vehicles (PHEV) to an existing residential photovoltaic system, to control and optimize the power consumption of residential load. Control involves determining the source from which residential load will be catered, where as optimization of power flow reduces the stress on the grid. The system built to achieve the goal is a combination of the existing residential photovoltaic system, PHEV, Power Conditioning Unit (PCU), and a controller. The PCU involves two DC-DC Boost Converters and an inverter. This paper emphasizes on developing the controller logic and its implementation in order to accommodate the flexibility and benefits of the proposed integrated system. The proposed controller logic has been simulated using MATLAB SIMULINK and further implemented using Digital Signal Processor (DSP) microcontroller, TMS320F28035, from Texas Instruments

Nagarajan, Adarsh; Shireen, Wajiha

2013-06-01

223

Damping Optimization by Integrating Enhanced Active Constrained Layer and Active-Passive Hybrid Constrained Layer Treatments  

NASA Astrophysics Data System (ADS)

The feasibility of integrating the enhanced active constrained layer (EACL) and active-passive hybrid constrained layer (HCL) treatments to achieve a better combination of the system's closed-loop damping and open-loop (fail-safe) damping (without active action) is investigated in this research. Given a uniform strain field in the host structure, the EACL with stiff and equal edge elements (symmetric EACL) has been shown to provide high closed-loop damping by significantly increasing the direct active control authority of the cover sheet. The open-loop damping of the system, however, could be low. On the other hand, the HCL has been demonstrated to offer more balanced open-loop and closed-loop damping actions, although the HCL closed-loop damping is not as high as that of the EACL. The idea here is therefore to combine the two approaches and develop an integrated HCL-EACL treatment. The focus is to maximize the system closed-loop damping while maintaining an open-loop damping margin for fail-safe reasons. For a given strain field in the host structure, optimization routines are used to search for the best design parameters: the optimal control gain, the stiffness of the edge elements and the active material coverage ratio in the constraining layer. It is found that integrating the EACL and the HCL will introduce more flexibility in the design of constrained layer damping treatments with actively enhanced actions. Higher open-loop damping can be achieved for the same closed-loop damping requirement and vice versa. The hybrid cover sheet is found to create significant shear in the viscoelastic layer while the edge elements are used to provide strong direct active control authority for the constraining layer. A better mixture of the open-loop and closed-loop damping can generally be obtained with the integrated system.

Liu, Y.; Wang, K. W.

2002-08-01

224

Optimal sizing of building integrated hybrid PV\\/diesel generator system for zero load rejection for Malaysia  

Microsoft Academic Search

In this research, an optimisation for building integrated hybrid PV\\/diesel generator system for zero load rejection for Malaysia is performed. The optimisation is performed considering a loss-of-load probability (LLP) less than 0.01. However, the daily averages of solar energy for Malaysia and a mathematical model of a hybrid PV\\/diesel generator system are used in this optimisation. The optimisation presented in

Tamer Khatib; A. Mohamed; K. Sopian; M. Mahmoud

2011-01-01

225

A transformerless hybrid active filter for integration into a medium-voltage motor drive with a passive front end  

Microsoft Academic Search

This paper discusses a transformerless hybrid active filter integrated into the 6.6-kV, 1-MW adjustable-speed motor drive having a three-phase diode rectifier at the front end. The hybrid filter consists of an active filter using a three-level diode-clamped PWM converter rated at 60 kVA, and a 250-kVA passive filter tuned to the 7th-harmonic frequency. They are directly connected in series without

Hirofumi Akagi

2007-01-01

226

Hybrid-integrated optical acceleration seismometer and its digital processing system  

NASA Astrophysics Data System (ADS)

Hybrid-integrated Optical acceleration seismometer and its digital signal processing system are researched and developed. The simple system figure of the seismometer is given. The principle of the seismometer is explicated. The seismometer is composed of a seismic mass,Integrated Optical Chips and a set of Michelson interferometer light path. The Michelson Integrated Optical Chips are critical parts among the sensor elements. The simple figure of the digital signal processing system is given. As an advanced quality digital signal processing (DSP) chip equipped with necessary circuits has been used in its digital signal processing system, a high accurate detection of the acceleration signal has been achieved and the environmental interference signal has been effectively compensated. Test results indicate that the accelerometer has better frequency response well above the resonant frequency, and the output signal is in correspondence with the input signal. The accelerometer also has better frequency response under the resonant frequency. At last, the curve of Seismometer frequency response is given.

En, De; Chen, Caihe; Cui, Yuming; Tang, Donglin; Liang, Zhengxi; Gao, Hongyu

2005-02-01

227

Integration of Xantrex HY-100 Hybrid Inverter with an AC Induction Wind Turbine  

SciTech Connect

Several issues must be addressed before solid-state inverters can be used in wind-diesel systems with larger wind turbines. This project addresses those issues by using a commercial hybrid inverter designed for PV-diesel systems and modifying the inverter for use with an AC induction wind turbine. Another approach would have entailed building an inverter specifically for use with an AC induction wind turbine, but that was beyond the scope of this project. The inverter chosen for this project was a Xantrex HY-100, an inverter designed for PV systems. The unit consists of an inverter/rectifier bridge, a generator interface contactor, a battery charge controller, a hybrid controller, and the associated control electronics. Details of the inverter may be found in Appendix A. A twofold approach was taken to integrating the existing inverter for use with an AC induction wind turbine: 1) development of a detailed model to model both steady-state and transient behavior of the system, and 2) modification and testing of the inverter with an induction wind turbine based on the modeling results. This report describes these two tasks.

Corbus, D.; Newcomb, C.; Friedly, S.

2003-05-01

228

Automatic on-chip RNA-DNA hybridization assay with integrated phase change microvalves  

NASA Astrophysics Data System (ADS)

An RNA-DNA hybridization assay microfluidic chip integrated with electrothermally actuated phase change microvalves for detecting pathogenic bacteria is presented in this paper. In order to realize the sequential loading and washing processes required in such an assay, gravity-based pressure-driven flow and phase-change microvalves were used in the microfluidic chip. Paraffin wax was used as the phase change material in the valves and thin film heaters were used to electrothermally actuate microvalves. Light absorption measured by a photodetector to determine the concentrations of the samples. The automatic control of the complete assay was implemented by a self-coded LabVIEW program. To examine the performance of this chip, Salmonella was used as a sample pathogen. Significantly, reduction in reagent/sample consumption (up to 20 folds) was achieved by this on-chip assay, compared with using the commercial test kit following the same protocol in conventional labs. The experimental results show that the quantitative detection can be obtained in approximately 26 min, and the detection limit is as low as 103 CFU ml-1. This RNA-DNA hybridization assay microfluidic chip shows an excellent potential in the development of a portable device for point-of-testing applications.

Weng, Xuan; Jiang, Hai; Wang, Junsheng; Chen, Shu; Cao, Honghe; Li, Dongqing

2012-07-01

229

Determination of chromosome copy numbers in Saccharomyces cerevisiae strains via integrative probe and blot hybridization techniques.  

PubMed

Methods have been devised for analyzing chromosome copy numbers in S. cerevisiae strains that may be polyploid or aneuploid, as is apparent in the case of many industrial strains. The initial step involved transformation of a strain with an integrative "ploidy probe" transplacement fragment that enabled the copy number of the targeted chromosomal locus to be determined via genomic Southern blotting and quantitative probe hybridization. Dual probe co-hybridization to Southern genomic DNA blots was used to extend such locus copy number determinations to other loci within the same chromosome, thereby screening for internal consistency along the length of the chromosome. This approach was also used to extend the analysis to other chromosomes in the genome. The method was established and verified with euploid series laboratory strains and then used to examine chromosome copy numbers in three industrial strains. One brewing strain apparently contained three copies of the chromosomes tested, whilst another brewing and a baking strain showed evidence of aneuploidy. PMID:7736605

Hadfield, C; Harikrishna, J A; Wilson, J A

1995-02-01

230

Integrated genome and transcriptome sequencing identifies a novel form of hybrid and aggressive prostate cancer†  

PubMed Central

Next-generation sequencing is making sequence-based molecular pathology and personalized oncology viable. We selected an individual initially diagnosed with conventional but aggressive prostate adenocarcinoma and sequenced the genome and transcriptome from primary and metastatic tissues collected prior to hormone therapy. The histology-pathology and copy number profiles were remarkably homogeneous, yet it was possible to propose the quadrant of the prostate tumour that likely seeded the metastatic diaspora. Despite a homogeneous cell type, our transcriptome analysis revealed signatures of both luminal and neuroendocrine cell types. Remarkably, the repertoire of expressed but apparently private gene fusions, including C15orf21:MYC, recapitulated this biology. We hypothesize that the amplification and over-expression of the stem cell gene MSI2 may have contributed to the stable hybrid cellular identity. This hybrid luminal-neuroendocrine tumour appears to represent a novel and highly aggressive case of prostate cancer with unique biological features and, conceivably, a propensity for rapid progression to castrate-resistance. Overall, this work highlights the importance of integrated analyses of genome, exome and transcriptome sequences for basic tumour biology, sequence-based molecular pathology and personalized oncology.

Wu, Chunxiao; Wyatt, Alexander W; Lapuk, Anna V; McPherson, Andrew; McConeghy, Brian J; Bell, Robert H; Anderson, Shawn; Haegert, Anne; Brahmbhatt, Sonal; Shukin, Robert; Mo, Fan; Li, Estelle; Fazli, Ladan; Hurtado-Coll, Antonio; Jones, Edward C; Butterfield, Yaron S; Hach, Faraz; Hormozdiari, Fereydoun; Hajirasouliha, Iman; Boutros, Paul C; Bristow, Robert G; Jones, Steven JM; Hirst, Martin; Marra, Marco A; Maher, Christopher A; Chinnaiyan, Arul M; Sahinalp, S Cenk; Gleave, Martin E; Volik, Stanislav V; Collins, Colin C

2013-01-01

231

Integrated genome and transcriptome sequencing identifies a novel form of hybrid and aggressive prostate cancer.  

PubMed

Next-generation sequencing is making sequence-based molecular pathology and personalized oncology viable. We selected an individual initially diagnosed with conventional but aggressive prostate adenocarcinoma and sequenced the genome and transcriptome from primary and metastatic tissues collected prior to hormone therapy. The histology-pathology and copy number profiles were remarkably homogeneous, yet it was possible to propose the quadrant of the prostate tumour that likely seeded the metastatic diaspora. Despite a homogeneous cell type, our transcriptome analysis revealed signatures of both luminal and neuroendocrine cell types. Remarkably, the repertoire of expressed but apparently private gene fusions, including C15orf21:MYC, recapitulated this biology. We hypothesize that the amplification and over-expression of the stem cell gene MSI2 may have contributed to the stable hybrid cellular identity. This hybrid luminal-neuroendocrine tumour appears to represent a novel and highly aggressive case of prostate cancer with unique biological features and, conceivably, a propensity for rapid progression to castrate-resistance. Overall, this work highlights the importance of integrated analyses of genome, exome and transcriptome sequences for basic tumour biology, sequence-based molecular pathology and personalized oncology. PMID:22294438

Wu, Chunxiao; Wyatt, Alexander W; Lapuk, Anna V; McPherson, Andrew; McConeghy, Brian J; Bell, Robert H; Anderson, Shawn; Haegert, Anne; Brahmbhatt, Sonal; Shukin, Robert; Mo, Fan; Li, Estelle; Fazli, Ladan; Hurtado-Coll, Antonio; Jones, Edward C; Butterfield, Yaron S; Hach, Faraz; Hormozdiari, Fereydoun; Hajirasouliha, Iman; Boutros, Paul C; Bristow, Robert G; Jones, Steven Jm; Hirst, Martin; Marra, Marco A; Maher, Christopher A; Chinnaiyan, Arul M; Sahinalp, S Cenk; Gleave, Martin E; Volik, Stanislav V; Collins, Colin C

2012-03-21

232

Integrated analysis of transcript, protein and metabolite data to study lignin biosynthesis in hybrid aspen.  

PubMed

Tree biotechnology will soon reach a mature state where it will influence the overall supply of fiber, energy and wood products. We are now ready to make the transition from identifying candidate genes, controlling important biological processes, to discovering the detailed molecular function of these genes on a broader, more holistic, systems biology level. In this paper, a strategy is outlined for informative data generation and integrated modeling of systematic changes in transcript, protein and metabolite profiles measured from hybrid aspen samples. The aim is to study characteristics of common changes in relation to genotype-specific perturbations affecting the lignin biosynthesis and growth. We show that a considerable part of the systematic effects in the system can be tracked across all platforms and that the approach has a high potential value in functional characterization of candidate genes. PMID:19053836

Bylesjö, Max; Nilsson, Robert; Srivastava, Vaibhav; Grönlund, Andreas; Johansson, Annika I; Jansson, Steffan; Karlsson, Jan; Moritz, Thomas; Wingsle, Gunnar; Trygg, Johan

2009-01-01

233

An integrated microfluidic chip for chromosome enumeration using fluorescence in situ hybridization.  

PubMed

Fluorescence in situ hybridization (FISH) is a powerful technique for probing the genetic content of individual cells at the chromosomal scale. Conventional FISH techniques provide a sensitive diagnostic tool for the detection of chromosomal alterations on a cell-by-cell basis; however, the cost-per-test in terms of reagent and highly qualified labour has prevented its wide-spread utilization in clinical settings. Here, we address the inefficient use of labour with the first integrated and automated on-chip FISH implementation, one that requires only minutes of setup time from the technician. Our microfluidic chip has lowered the reagent use by 20-fold, decreased the labour time by 10-fold, and substantially reduced the amount of support equipment needed. We believe this cost-effective platform will make sensitive FISH techniques more accessible for routine clinical usage. PMID:19023479

Sieben, Vincent J; Debes-Marun, Carina S; Pilarski, Linda M; Backhouse, Christopher J

2008-10-23

234

Ultrafast optical signal processing with hybrid-integrated symmetric Mach-Zehnder all-optical switches  

NASA Astrophysics Data System (ADS)

We report on various types of ultrafast all-optical signal processing with hybrid-integrated Symmetric-Mach-Zehnder (HI-SMZ) all-optical switches driven by 40-Gb/s or 40-GHz optical pulses. To operate HI-SMZ switches with such high-repetition excitation, we use longer semiconductor optical amplifiers (SOAs) as nonlinear phase shifters than we previously used. We demonstrate that extending the SOA length is useful for increasing carrier injection and thus enhancing the nonlinear phase shift in SOAs. We show 3R regeneration and wavelength conversion at 42 Gb/s using HI-SMZ switches with longer SOAs. We also show error-free optical demultiplexing of 168- or 336-Gb/s signal pulses with HI-SMZ switches driven by 42-GHz control pulses.

Nakamura, Shigeru; Tamanuki, Takemasa; Takahashi, Morio; Shimizu, Takanori; Ae, Satoshi; Mori, Kazuo; Furukawa, Akio; Sasaki, Tatsuya; Tajima, Kazuhito

2003-08-01

235

Simulation of solar-powered ammonia-water integrated hybrid cooling system  

SciTech Connect

a number of solar-operated air-conditioning systems based on the H{sub 2}O-LiBr absorption chiller were built, installed, and monitored. A systematic study at the University of Colorado has been published. This paper presents a simple cost-benefit analysis of the conventional vapor compression system (VCS), the vapor absorption system (VAS), and the integrated hybrid system (IHS). The cost of energy input to the VAS and the IHS were compared with the energy cost of the VCS that these solar-powered systems replace. It was found that cost savings can be realized with solar-powered systems, only after a critical overall solar fraction is exceeded. Typically, this value was about 0.7 for a VAS and about 0.12 for a IHS. These cost-benefit results provided the motivation for a more detailed study of the IHS. There has also been other efforts in this direction.

Chinnappa, J.C.V. (James Cook Univ., Townsville 4811 (AU)); Wijeysundera, N.E. (Dept. of Mechanical and Production Engineering, National Univ. of Singapore (SG))

1992-05-01

236

Silicon hybrid wafer scale integration interconnect performance evaluation at RF frequencies  

NASA Astrophysics Data System (ADS)

The RF electrical characteristics of hybrid wafer scale integration (WSI) interconnections on silicon-polyimide-aluminum and silicon-benzocyclobutene-aluminum substrates have been evaluated. The silicon wafer substrates were five in in diameter, and each contained an identical set of 200 photolithographically patterned dielectric and aluminum interconnect test structures. The aluminum conductors were 2.5-microns thick, and half of the test structure conductors were 10-microns wide, while the remainder were 25-microns wide. Measurements between 5 kHz and 220 MHz confirmed the expected transmission line behavior manifested by the longer interconnections. The coupling levels in the 400 line/cm density structures are low, but nevertheless significant, especially when digital logic applications requiring low-noise margins are anticipated. More important were the attenuation effects manifested by the longer aluminum interconnections when they were combined with low-impedence matched terminations.

Lyke, James C., Jr.; Kolesar, Edward S., Jr.

237

A Hybrid Integrated-Circuit/Microfluidic Device for Positioning, Porating and Fusing Individual Cells  

NASA Astrophysics Data System (ADS)

Here we report a hybrid integrated-circuit/microfluidic device which can position, porate and fuse individual cells. Existing electroporation and fusion devices can only act on cells in bulk. Our device consists of a microarray of electrode pixels^1 and a grounded conducting plate. Cells were positioned with dielectrophoretic forces induced by the pixels and porated or fused with voltage pulses which caused a dielectric breakdown of the cell membrane. The device positioned cells with 10?m precision and porated or fused them with high yields. It is programmable and mass-parallelization on a single device enables bulk applications. ^1 T. Hunt, D. Issadore, R. Westervelt, Lab on a Chip, 2008, 8, 81-87.

Floryan, Caspar; Issadore, David; Westervelt, Robert

2010-03-01

238

Electrocoagulation-integrated hybrid membrane processes for the treatment of tannery wastewater.  

PubMed

Three different combinations of treatment techniques, i.e. electrocoagulation combined with microfiltration (EMR), membrane bioreactor (MBR) and electrocoagulation integrated with membrane bioreactor (hybrid MBR, (HMBR)), were analysed and compared for the treatment of tannery wastewater operated for 7 days under the constant trans-membrane pressure of 5 kPa. HMBR was found to be most suitable in performance as well as fouling reduction, with 94 % of chemical oxygen demand (COD) removal, 100 % chromium removal and 8 % improvement in percentage reduction in permeate flux compared to MBR with only 90 % COD removal and 67 % chromium removal. The effect of mixed liquor suspended solids on fouling was also investigated and was found to be insignificant. EMR was capable of elevating the flux but was not as efficient as HMBR and MBR in COD removal. Fouling reduction by HMBR was further confirmed by SEM-EDX and particle size analysis. PMID:23653316

Keerthi; Vinduja, V; Balasubramanian, N

2013-05-08

239

A hybrid design methodology for structuring an Integrated Environmental Management System (IEMS) for shipping business.  

PubMed

The International Safety Management (ISM) Code defines a broad framework for the safe management and operation of merchant ships, maintaining high standards of safety and environmental protection. On the other hand, ISO 14001:2004 provides a generic, worldwide environmental management standard that has been utilized by several industries. Both the ISM Code and ISO 14001:2004 have the practical goal of establishing a sustainable Integrated Environmental Management System (IEMS) for shipping businesses. This paper presents a hybrid design methodology that shows how requirements from both standards can be combined into a single execution scheme. Specifically, the Analytic Hierarchy Process (AHP) and Fuzzy Axiomatic Design (FAD) are used to structure an IEMS for ship management companies. This research provides decision aid to maritime executives in order to enhance the environmental performance in the shipping industry. PMID:19038488

Celik, Metin

2008-11-28

240

Integrating Circuit Level Simulation and Monte-Carlo Radiation Transport Code for Single Event Upset Analysis in SEU Hardened Circuitry  

Microsoft Academic Search

Monte-Carlo radiation transport code is coupled with SPICE circuit level simulation to identify regions of single event upset vulnerability in an SEU hardened flip-flop, as well as predict single event upset cross sections and on-orbit soft error rates under static and dynamic operating conditions.

Kevin M. Warren; Andrew L. Sternberg; Robert A. Weller; Mark P. Baze; Lloyd W. Massengill; Robert A. Reed; Marcus H. Mendenhall; Ronald D. Schrimpf

2008-01-01

241

Monte Carlo analysis of a time-dependent neutron and secondary gamma-ray integral experiment on a thick concrete and steel shield  

NASA Astrophysics Data System (ADS)

A Monte Carlo analysis of a time-dependent neutron and secondary gamma-ray integral experiment on a thick concrete and steel shield is presented. The energy range covered in the analysis is 15-2 MeV for neutron source energies. The multigroup MORSE code was used with the VITAMIN C 171-36 neutron-gamma-ray cross-section data set. Both neutron and gamma-ray count rates and unfolded energy spectra are presented and compared, with good general agreement, with experimental results.

Cramer, S. N.; Roussin, R. W.

1981-11-01

242

Interacting bosons in one dimension and the applicability of Luttinger-liquid theory as revealed by path-integral quantum Monte Carlo calculations  

NASA Astrophysics Data System (ADS)

Harmonically trapped ultracold atoms and H4e in nanopores provide different experimental realizations of bosons in one dimension, motivating the search for a more complete theoretical understanding of their low-energy properties. Worm algorithm path-integral quantum Monte Carlo results for interacting bosons restricted to the one dimensional continuum are compared to the finite temperature and system size predictions of Luttinger-liquid theory. For large system sizes at low temperature, excellent agreement is obtained after including the leading irrelevant interactions in the Hamiltonian which are determined explicitly.

Del Maestro, Adrian; Affleck, Ian

2010-08-01

243

Solving an integrated employee timetabling and job-shop scheduling problem via hybrid branch-and-bound  

Microsoft Academic Search

We propose exact hybrid methods based on integer linear programming and constraint programming for an integrated employee timetabling and job-shop scheduling problem. Each method we investigate uses a constraint programming (CP) formulation associated with a linear programming (LP) relaxation. Under a CP framework, the LP-relaxation is integrated into a global constraint using in addition reduced cost-based filtering techniques. We propose

Christian Artigues; Michel Gendreau; Louis-Martin Rousseau; Adrien Vergnaud

2009-01-01

244

Software design for sequential/hybrid time integration in the Community Climate System Model  

NASA Astrophysics Data System (ADS)

All current releases of the Community Climate System Model (CCSM) have employed a concurrent integration scheme where the four main components, the atmosphere, ocean, land and sea ice models, are scheduled to execute concurrently on separate sets of processors. Although in theory this can make more efficient use of large numbers of processors, in practice data serialization between the models leads to idle processors and finding an optimum load balance between models and processors is not straightforward. For the next release of CCSM, we are developing a version that executes each model in sequence while decomposing the space domain over the same number of processors. The advantages of this system include no idle time, more efficient use of small numbers of processors and removal of the load-balancing problem. It should also be more straightforward to add new components to the system. We have employed the same coupling software, the Model Coupling Toolkit, as used in the current CCSM to build the prototype sequential system. The sequential CCSM will support all of the features of the released CCSM including the ability to couple data or full models and coupling the ocean at different frequencies. We are also developing a hybrid integration scheme where the ocean model executes concurrently with a sequential atmosphere, land and sea ice system. This two- component system will be much easier to load balance and can provide the best combination of performance and efficiency on large processor counts.

Jacob, R.; Vertenstein, M.; Craig, T.; Dennis, J.; Kauffman, B.

2007-12-01

245

First application close measurements applying the new hybrid integrated MEMS spectrometer  

NASA Astrophysics Data System (ADS)

Grating spectrometers have been designed in many different configurations. Now potential high volume applications ask for extremely miniaturized and low cost systems. By the use of integrated MEMS (micro electro mechanical systems) scanning grating devices a less expensive single detector can be used in the NIR instead of the array detectors required for fixed grating systems. Meanwhile the design of a hybrid integrated MEMS scanning grating spectrometer has been drawn. The MEMS device was fabricated in the Fraunhofer IPMS own clean room facility. This chip is mounted on a small circuit board together with the detector and then stacked with spacer and mirror substrate. The spectrometer has been realized by stacking several planar substrates by sophisticated mounting technologies. The spectrometer has been designed for the 950nm - 1900nm spectral range and 9nm spectral resolution with organic matter analysis in mind. First applications are considered in the food quality analysis and food processing technology. As example for the use of a spectrometer with this performance the grill process of steak was analyzed. Similar measurement would be possible on dairy products, vegetables or fruit. The idea is a mobile spectrometer for in situ and on site analysis applications in or attached to a host system providing processing, data access and input-output capabilities, disregarding this would be a laptop, tablet, smart phone or embedded platform.

Grüger, Heinrich; Pügner, Tino; Knobbe, Jens; Schenk, Harald

2013-05-01

246

SiGe Integrated Circuit/SQUID Hybrid Cryogenic Multiplexer for Superconducting Bolometer Array  

NASA Astrophysics Data System (ADS)

The development of large superconducting bolometer (Transition Edge Sensor: TES) arrays requires ultra low noise amplification and multiplexing electronics. The use of a first transducer stage such as a SQUID (Superconducting QUantum Interference Device) allows ultimate performance in terms of noise. However, the linearization of the SQUID characteristic requires low noise amplification. Furthermore, to realize a time domain multiplexer with SQUIDs, switched biasing is also needed. We have designed an Integrated Circuit (IC) in standard BiCMOS SiGe technology for the readout and the control of a SQUID multiplexer. It includes a low noise amplifier with multiplexed inputs, switched current sources for SQUIDs, and digital circuit for the addressing with only one room temperature clock signal. We have successfully tested this integrated circuit down to 2 K. To validate the operation of a SQUID multiplexer controlled by this SiGe cryogenic IC, we have developed a 2×2 SQUID hybrid demonstrator. It consists of four commercial SQUIDs connected to a SiGe IC.

Prêle, D.; Voisin, F.; Oger, R.; Chapron, C.; Bréelle, E.; Piat, M.

2009-12-01

247

A new full-wave hybrid differential-integral approach for the investigation of multilayer structures including nonuniformly doped diffusions  

Microsoft Academic Search

A novel hybrid differential-integral approach, based on the transverse wave formulation (TWF) is presented for full-wave investigation of multilayer structures including inhomogeneous layer stacks with arbitrary doping profiles. In combining both the benefits of spatial and spectral resolutions, the TWF offers a natural framework for the implementation of multiresolution and multiscale approaches from physical considerations. The possibility of separating the

Sidina Wane; Damienne Bajon; Henri Baudrand; Patrice Gamand

2005-01-01

248

A family of time-staggered schemes for integrating hybrid DPD models for polymers: Algorithms and applications  

Microsoft Academic Search

We propose new schemes for integrating the stochastic differential equations of dissipative particle dynamics (DPD) in simulations of dilute polymer solutions. The hybrid DPD models consist of hard potentials that describe the microscopic dynamics of polymers and soft potentials that describe the mesoscopic dynamics of the solvent. In particular, we develop extensions to the velocity-Verlet and Lowe’s approaches – two

Vasileios Symeonidis; George Em. Karniadakis

2006-01-01

249

Integrated Array-Comparative Genomic Hybridization and Expression Array Profiles Identify Clinically Relevant Molecular Subtypes of Glioblastoma  

Microsoft Academic Search

Glioblastoma, the most aggressive primary brain tumor in humans, exhibits a large degree of molecular heterogeneity. Understanding the molecular pathology of a tumor and its linkage to behavior is an important foundation for developing and evaluating approaches to clinical management. Here we integrate array-comparative genomic hybridization and array- based gene expression profiles to identify relationships between DNA copy number aberrations,

Janice M. Nigro; Anjan Misra; Ivan Smirnov; Howard Colman; Chandi Griffin; Natalie Ozburn; Mingang Chen; Edward Pan; Dimpy Koul; Burt G. Feuerstein; Kenneth D. Aldape

2005-01-01

250

The Challenges and Policy Options for Integrating Plug-in Hybrid Electric Vehicle into the Electric Grid  

Microsoft Academic Search

Plug-in hybrid electric vehicle may be prime candidates for the next generation of vehicles, but they offer several technological and economical challenges. This article assesses current progress in PHEV technology, market trends, research needs, challenges ahead and policy options for integrating PHEVs into the electric grid.

Anurag K. Srivastava; Bharath Annabathina; Sukumar Kamalasadan

2010-01-01

251

Novel Modulation Concepts for a Drive-Integrated Auxiliary Dc-Dc Converter for Hybrid Vehicles  

Microsoft Academic Search

Hybrid vehicles are a characteristic feature of the daily traffic yet, with growing fuel costs and other factors increasing their importance in the nearest future even more. Nevertheless, hybrid vehicles are not a mass product up to now. Although the life cycle costs of the hybrid cars are usually smaller than the costs for comparable fuel vehicles, the main purchase

H. Plesko; J. Biela; J. W. Kolar

2009-01-01

252

Design and construction of a VHGT-attached WDM-type triplex transceiver module using polymer PLC hybrid integration technology  

NASA Astrophysics Data System (ADS)

We report about design and construction of the bidirectional transceiver TRx module for subscriber part of the passive optical network PON for a fiber to the home FTTH topology. The TRx module consists of a epoxy novolak resin polymer planar lightwave circuit (PLC) hybrid integration technology with volume holographic grating triplex filter VHGT, surface-illuminated photodetectors and spot-size converted Fabry-Pérot laser diode in SMD package. The hybrid PLC has composed from a two parts-polymer optical waveguide including VHGT filter section and a optoelectronic microwave section. The both parts are placed on the composite substrate.

Jerábek, Vitezslav; Hüttel, Ivan; Prajzler, Václav; Busek, K.; Seliger, P.

2008-11-01

253

Hybrid MnO2 Film with Agarose Gel for Enhancing the Structural Integrity of Thin Film Supercapacitor Electrodes.  

PubMed

We report on the fabrication of a robust hybrid film containing MnO2 for achieving large areal capacitances. An agarose gel, as an ion-permeable and elastic layer coated on a current collector, plays a key role in stabilizing the deposited pseudocapacitive MnO2. Cyclic voltammetry and electrochemical impedance spectroscopy data indicate that the hybrid electrode is capable of exhibiting a high areal capacitance up to 52.55 mF cm(-2), with its superior structural integrity and adhesiveness to the current collector being maintained, even at a high MnO2 loading. PMID:24080145

Park, Soomin; Nam, Inho; Kim, Gil-Pyo; Han, Jeong Woo; Yi, Jongheop

2013-10-03

254

Integrated Plasma Simulation of Ion Cyclotron and Lower Hybrid Range of Frequencies Actuators in Tokamaks  

NASA Astrophysics Data System (ADS)

Recent upgrades to the ion cyclotron RF (ICRF) and lower hybrid RF (LHRF) components of the Integrated Plasma Simulator [1] have made it possible to simulate LH current drive in the presence of ICRF minority heating and mode conversion electron heating. The background plasma is evolved in these simulations using the TSC transport code [2]. The driven LH current density profiles are computed using advanced ray tracing (GENRAY) and Fokker Planck (CQL3D) [3] components and predictions from GENRAY/CQL3D are compared with a ``reduced'' model for LHCD (the LSC [4] code). The ICRF TORIC solver is used for minority heating with a simplified (bi-Maxwellian) model for the non-thermal ion tail. Simulation results will be presented for LHCD in the presence of ICRF heating in Alcator C-Mod. [4pt] [1] D. Batchelor et al, Journal of Physics: Conf. Series 125, 012039 (2008).[0pt] [2] S. C. Jardin et al, J. Comp. Phys. 66, 481 (1986).[0pt] [3] R. W. Harvey and M. G. McCoy, Proc. of the IAEA Tech. Comm. Meeting on Simulation and Modeling of Therm. Plasmas, Montreal, Canada (1992).[0pt] [4] D. Ignat et al, Nucl. Fus. 34, 837 (1994).[0pt] [5] M. Brambilla, Plasma Phys. and Cont. Fusion 41,1 (1999).

Bonoli, P. T.; Shiraiwa, S.; Wright, J. C.; Harvey, R. W.; Batchelor, D. B.; Berry, L. A.; Chen, Jin; Poli, F.; Kessel, C. E.; Jardin, S. C.

2012-10-01

255

Fabrication of a TFF-Attached WDM-Type Triplex Transceiver Module Using Silica PLC Hybrid Integration Technology  

Microsoft Academic Search

An optical triplex transceiver (TRx) module, which consists of thin-film filter (TFF)-attached wavelength-division multiplexer (WDM) and photodiode (PD) carriers, has been fabricated using a silica planar lightwave circuit (PLC) hybrid integration technology. Two types of TFFs were attached to a diced sidewall of a silica-terraced PLC platform to realize the TFF-attached WDM. The PD carriers with a 45deg mirror, on

Young-Tak Han; Yoon-Jung Park; Sang-Ho Park; Jang-Uk Shin; Chul-Wook Lee; Hyunsung Ko; Yongsoon Baek; Chul-Hee Park; Yoon-Koo Kwon; Wol-Yon Hwang; Kwang-Ryong Oh; Heekyung Sung

2006-01-01

256

System Integration and Power-Flow Management for a Series Hybrid Electric Vehicle Using Supercapacitors and Batteries  

Microsoft Academic Search

In this paper, system integration and power-flow management algorithms for a four-wheel-driven series hybrid electric vehicle (HEV) having multiple power sources composed of a diesel-engine-based generator, lead acid battery bank, and supercapacitor bank are presented. The super-capacitor is utilized as a short-term energy storage device to meet the dynamic performance of the vehicle, while the battery is utilized as a

Hyunjae Yoo; Seung-Ki Sul; Yongho Park; Jongchan Jeong

2008-01-01

257

Project Integration Office for the electric and hybrid vehicle R and D program. Eighth progress report, March 1982  

SciTech Connect

The Project Integration Office (PIO) was established to assist the US DOE with the direction and coordination of its multiple electric vehicle and hybrid electric vehicle research programs in order to get the maximum payoff from these research efforts. In addition, the PIO performs objective independent technical and economic studies, analyses and modeling, and maintains a technical information liaison service to facilitate information exchange between the program participants and industry. Progress in each of these activities is reported. (LCL)

Not Available

1982-04-19

258

Implementation of screened hybrid density functional for periodic systems with numerical atomic orbitals: basis function fitting and integral screening.  

PubMed

We present an efficient O(N) implementation of screened hybrid density functional for periodic systems with numerical atomic orbitals (NAOs). NAOs of valence electrons are fitted with gaussian-type orbitals, which is convenient for the calculation of electron repulsion integrals and the construction of Hartree-Fock exchange matrix elements. All other parts of Hamiltonian matrix elements are constructed directly with NAOs. The strict locality of NAOs is adopted as an efficient two-electron integral screening technique to speed up calculations. PMID:21786990

Shang, Honghui; Li, Zhenyu; Yang, Jinlong

2011-07-21

259

Dual Beam Generator Incorporating a Guided-Wave Beam Aligner Hybrid Integrated with Infrared and Visible Laser Diodes  

NASA Astrophysics Data System (ADS)

A compact dual beam generator was realized by exploiting an integrated optic beam aligner accompanied by an aspheric lens, to deliver collinear infrared (IR) and visible collimated beams. The aligner entails straight and bent silica waveguides for IR and visible channels, respectively, which are hybrid integrated with laser diodes at ?=905 and 605 nm. The guided-wave aligner is fixed to IR and visible laser diodes via active power monitoring, then combined with a lens to construct a 35-mm-long beam generator. The produced IR and visible collimated beams feature profiles with a divergence of ˜0.1° and an angular alignment of 0.13°.

Lee, Hong-Shik; Shrestha, Vivek Raj; Lee, Sang-Shin

2013-02-01

260

Planar Integrated Optical Detection of a Hybrid Long-Range Surface Plasmon Using an InGaAs Inverted-MSM Detector Bonded to Silicon  

Microsoft Academic Search

An InxGa1-xAs thin-film inverted metal-semiconductor-metal photodetector has been integrated with a gold hybrid long-range surface plasmon waveguide on silicon. This integrated structure enables planar integrated optical detection of a long-range surface plasmon wave at a wavelength of 1.55 ?m.

Sulochana Dhar; Aloyse Degiron; David R. Smith; Nan M. Jokerst

2010-01-01

261

Identifying the medical practice after total hip arthroplasty using an integrated hybrid approach.  

PubMed

A critical option of total hip arthroplasty (THA) is considered only when tried more conservative treatments but continued to have pain, stiffness, or problems with the function of ones hip. THA plays one of major concerns under the waves of the rapid growth of aging populations and the constrained health care resources in Taiwan. Moreover, prior studies indicated that imbalanced class distribution problems do exist in the constructed classification model and cause seriously negative effects on model performances in the health care industry. Therefore, this study proposes an integrated hybrid approach to provide an alternate method for classifying the quality (e.g., the staying length in hospital) of medical practice with an imbalanced class problem after performing a THA procedure for hip replacement patients and their doctors in the health care industry. The proposed approach is constituted by seven components: expert knowledge, global discretization, imbalanced bootstrap technique, reduct and core methods, rough sets, rule induction, and rule filter. The proposed approach is illustrated in practice by examining an experimental dataset from the National Health Insurance Research Database (NHIRD) in Taiwan. The experimental results reveal that the proposed approach has better performance than the listed methods under evaluation criteria. The output created by the rough set LEM2 algorithm is a comprehensible decision rule set that can be applied in knowledge-based health care services as desired. The analytical results provide useful THA information for both academics and practitioners and these results could be applicable to other diseases or to other countries with similar social and cultural practices. PMID:22795228

Chen, You-Shyang; Cheng, Ching-Hsue

2012-07-15

262

Novel Concepts for Integrating the Electric Drive and Auxiliary Dc-Dc Converter for Hybrid Vehicles  

Microsoft Academic Search

Cost, volume and weight are three major driving forces in the automotive area. This is also true for hybrid vehicles which attract more and more attention due to increasing fuel costs and air pollution. In hybrid vehicles the energy distribution system causes a significant share of the volume and the costs. In order to reduce the costs and the volume

H. Pleskol; J. Biela; J. Luomi; J. W. Kolar

2007-01-01

263

Novel Concepts for Integrating the Electric Drive and Auxiliary DC–DC Converter for Hybrid Vehicles  

Microsoft Academic Search

Cost, volume, and weight are three major driving forces in the automotive area. This is also true for hybrid electric vehicles, which are attracting more and more attention due to increasing fuel costs and air pollution. In hybrid vehicles, the energy distribution system causes a significant share of the volume and the costs. One part of this system is the

Hanna Plesko; Jorma Luomi; Johann W. Kolar

2008-01-01

264

Integration of maize nuclear and mitochondrial DNA into the wheat genome through somatic hybridization  

Microsoft Academic Search

Protoplasts were isolated from cultured cells of wheat and maize and fused using PEG. Calli and green plants were regenerated following irradiation of the maize, and some tested positive for hybridity using morphological, isozymic and various DNA-based marker systems. Genomic in situ hybridization (GISH) of selected maize-carrying regenerants showed that some maize chromatin was dispersed throughout the wheat nuclear genome.

Chunhui Xu; Guangmin Xia; Daying Zhi; Fengning Xiang; Huimin Chen

2003-01-01

265

Integrated voltage regulation and current-sensorless power tracking control for a DC hybrid power system  

Microsoft Academic Search

Hybrid power systems combine two or more complementary power generation technologies to achieve the system performance that is not possible for those involving a single power technology. The complicated dynamic interactions of the hybrid power system elements, coupled with stringent safety, power quality and efficiency requirements, impose challenging control and dynamic optimization problems. This paper presents a novel approach that

Yanhui Xie; Jing Sun; James S. Freudenberg

2008-01-01

266

Multigrid Monte Carlo methods  

SciTech Connect

This paper is intended to be a tutorial on multigrid Monte Carlo techniques, illustrated with two examples. Path-integral quantum Monte Carlo is seen to take only a finite amount of computer time even as the paths are discretized on infinitesimally small scales. A method for eliminating critical slowing down completely/emdash/even for models with discrete degrees of freedom, as in Potts models, or discrete excitations, such as isolated vortices in the XY model/emdash/is presented. 11 refs., 1 fig.

Loh, E. Jr.

1988-01-01

267

Calculation of stress intensity factors for an interfacial crack between dissimilar anisotropic media, using a hybrid element method and the mutual integral  

Microsoft Academic Search

Using Beom and Atluri's complete eigen-function solutions for stresses and displacements near the tip of an interfacial crack between dissimilar anisotropic media, a hybrid crack tip finite-element is developed. This element, as well as a mutual integral method are used to determine the stress intensity factors for an interfacial crack between dissimilar anisotropic media. The hybrid element has, for its

W. T. Chow; H. G. Beom; S. N. Atluri

1995-01-01

268

ITS version 5.0 : the integrated TIGER series of coupled electron/photon Monte Carlo transport codes.  

SciTech Connect

ITS is a powerful and user-friendly software package permitting state of the art Monte Carlo solution of linear time-independent couple electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 5.0, the latest version of ITS, contains (1) improvements to the ITS 3.0 continuous-energy codes, (2)multigroup codes with adjoint transport capabilities, and (3) parallel implementations of all ITS codes. Moreover the general user friendliness of the software has been enhanced through increased internal error checking and improved code portability.

Franke, Brian Claude; Kensek, Ronald Patrick; Laub, Thomas William

2004-06-01

269

An improved solution for integrated array optics in quasi-optical mm and submm receivers: The hybrid antenna  

SciTech Connect

The hybrid antenna discussed here is defined as a dielectric lens-antenna as a special case of an extended hemispherical dielectric lens that is operated in the diffraction limited regime. It is a modified version of the planar antenna on a lens scheme developed by Rutledge. The dielectric lens-antenna is fed by a planar-structure antenna, which is mounted on the flat side of the dielectric lens-antenna using it as a substrate, and the combination is termed a hybrid antenna. Beam pattern and aperture efficiency measurements were made at millimeter and submillimeter wavelengths as a function of extension of the hemispherical lens and different lens sizes. An optimum extension distance is found experimentally and numerically for which excellent beam patterns and simultaneously high aperture efficiencies can be achieved. At 115 GHz the aperture efficiency was measured to be (76 [+-] 6)% for a diffraction limited beam with sidelobes below [minus]17 dB. Results of a single hybrid antenna with an integrated Superconductor-Insulator-Superconductor (SIS) detector and a broad-band matching structure at submillimeter wavelengths are presented. The hybrid antenna is diffraction limited, space efficient in an array due to its high aperture efficiency, and is easily mass produced, thus being well suited for focal plane heterodyne receiver arrays.

Buettgenback, T.H. (California Inst. of Tech., Pasadena, CA (United States). Div. of Physics)

1993-10-01

270

Hybrid integration of waveguide photodetectors with silicon-on-insulator micro-ring resonator on silicon substrate  

NASA Astrophysics Data System (ADS)

To integrate compound semiconductors with foreign substrates can lead to superior or novel functionalities. The design and fabrication of heterogeneously integrated waveguide photodetectors with Silicon-on-Insulator micro-ring resonator are reported in this paper. The micro-ring resonator was fabricated by utilizing electron beam lithography and inductively-coupled-plasma reactive ion etching technique, which is used for wavelength selectivity. The waveguide photodetectors fabricated by wet etching were used for light detection. The free spectral range (FSR) of the hybrid integrated device was about 24 nm, and the dark current of 7.9 nA was achieved at the reverse bias voltage of 2.0 V. The measured response of the photodetector at through port was 0.538 ?A/W at the wavelength of 1556 nm and a reverse bias of 1 V.

Hu, Fuquan; Huang, Yongqing; Duan, Xiaofeng; Zhang, Xu; Fan, Xinye; Shang, Yufeng; Cai, Shiwei; Wang, Wei; Ren, Xiaomin

2013-01-01

271

Fast and robust extraction of optical and morphological properties of human skin using a hybrid stochastic–deterministic algorithm: Monte-Carlo simulation study  

Microsoft Academic Search

A hybrid deterministic–stochastic algorithm combining the simplex method (SM) and a genetic algorithm (GA) was applied to\\u000a the problem of extracting the optical and morphological properties of human skin (HSOMPs) from visual reflectance spectroscopy\\u000a data. The results using the GA-SM hybrid algorithm adopting tournament selection and selecting new sets of HSOMPs were compared\\u000a with those using other conventional optimization algorithms

Seung Ho Choi

2010-01-01

272

Hybrid Adeno-Associated Viral Vectors Utilizing Transposase-Mediated Somatic Integration for Stable Transgene Expression in Human Cells  

PubMed Central

Recombinant adeno-associated viral (AAV) vectors have been shown to be one of the most promising vectors for therapeutic gene delivery because they can induce efficient and long-term transduction in non-dividing cells with negligible side-effects. However, as AAV vectors mostly remain episomal, vector genomes and transgene expression are lost in dividing cells. Therefore, to stably transduce cells, we developed a novel AAV/transposase hybrid-vector. To facilitate SB-mediated transposition from the rAAV genome, we established a system in which one AAV vector contains the transposon with the gene of interest and the second vector delivers the hyperactive Sleeping Beauty (SB) transposase SB100X. Human cells were infected with the AAV-transposon vector and the transposase was provided in trans either by transient and stable plasmid transfection or by AAV vector transduction. We found that groups which received the hyperactive transposase SB100X showed significantly increased colony forming numbers indicating enhanced integration efficiencies. Furthermore, we found that transgene copy numbers in transduced cells were dose-dependent and that predominantly SB transposase-mediated transposition contributed to stabilization of the transgene. Based on a plasmid rescue strategy and a linear-amplification mediated PCR (LAM-PCR) protocol we analysed the SB100X-mediated integration profile after transposition from the AAV vector. A total of 1840 integration events were identified which revealed a close to random integration profile. In summary, we show for the first time that AAV vectors can serve as template for SB transposase mediated somatic integration. We developed the first prototype of this hybrid-vector system which with further improvements may be explored for treatment of diseases which originate from rapidly dividing cells.

Zhang, Wenli; Solanki, Manish; Muther, Nadine; Ebel, Melanie; Wang, Jichang; Sun, Chuanbo; Izsvak, Zsuzsanna; Ehrhardt, Anja

2013-01-01

273

Hybrid adeno-associated viral vectors utilizing transposase-mediated somatic integration for stable transgene expression in human cells.  

PubMed

Recombinant adeno-associated viral (AAV) vectors have been shown to be one of the most promising vectors for therapeutic gene delivery because they can induce efficient and long-term transduction in non-dividing cells with negligible side-effects. However, as AAV vectors mostly remain episomal, vector genomes and transgene expression are lost in dividing cells. Therefore, to stably transduce cells, we developed a novel AAV/transposase hybrid-vector. To facilitate SB-mediated transposition from the rAAV genome, we established a system in which one AAV vector contains the transposon with the gene of interest and the second vector delivers the hyperactive Sleeping Beauty (SB) transposase SB100X. Human cells were infected with the AAV-transposon vector and the transposase was provided in trans either by transient and stable plasmid transfection or by AAV vector transduction. We found that groups which received the hyperactive transposase SB100X showed significantly increased colony forming numbers indicating enhanced integration efficiencies. Furthermore, we found that transgene copy numbers in transduced cells were dose-dependent and that predominantly SB transposase-mediated transposition contributed to stabilization of the transgene. Based on a plasmid rescue strategy and a linear-amplification mediated PCR (LAM-PCR) protocol we analysed the SB100X-mediated integration profile after transposition from the AAV vector. A total of 1840 integration events were identified which revealed a close to random integration profile. In summary, we show for the first time that AAV vectors can serve as template for SB transposase mediated somatic integration. We developed the first prototype of this hybrid-vector system which with further improvements may be explored for treatment of diseases which originate from rapidly dividing cells. PMID:24116154

Zhang, Wenli; Solanki, Manish; Müther, Nadine; Ebel, Melanie; Wang, Jichang; Sun, Chuanbo; Izsvak, Zsuzsanna; Ehrhardt, Anja

2013-10-08

274

Sequential Monte Carlo Methods to Train Neural Network Models  

Microsoft Academic Search

We discuss a novel strategy for training neural networks using sequential Monte Carlo algorithms and propose a new hybrid gradient descent\\/sampling importance resampling algorithm (HySIR). In terms of computational time and accuracy, the hybrid SIR is a clear improvement over conventional sequential Monte Carlo techniques. The new algorithm may be viewed as a global optimization strategy that allows us to

João F. G. De Freitas; Mahesan Niranjan; Andrew H. Gee; Arnaud Doucet

2000-01-01

275

Design of pass band filter in hybrid architecture planar\\/NRD waveguide integration technology  

Microsoft Academic Search

In this paper, we present a design of a non-radiative dielectric waveguide band pass filter based on hybrid architecture of micro-strip line and non-radiative dielectric waveguide. The simulation with high frequency structure simulator (HFSS) three dimensional analyses are presented, also the influence of the feeding transitions for circuit design is studied.

Harizi Hanen; Gharssallah Ali

2012-01-01

276

Hybrid information privacy system: integration of chaotic neural network and RSA coding  

Microsoft Academic Search

Electronic mails are adopted worldwide; most are easily hacked by hackers. In this paper, we purposed a free, fast and convenient hybrid privacy system to protect email communication. The privacy system is implemented by combining private security RSA algorithm with specific chaos neural network encryption process. The receiver can decrypt received email as long as it can reproduce the specified

Ming-Kai Hsu; Jeff Willey; Ting N. Lee; Harold H. Szu

2005-01-01

277

Ferroelectric materials and IR bolometer arrays: From hybrid arrays towards integration  

Microsoft Academic Search

Large arrays of bolometer elements offer uncooled and simple operation, and a thermal imaging performance which challenges the cooled semiconductor (photon) detectors. A hybrid array technology, exploiting the pyroelectric property of ferroelectric ceramic materials in the bolometer elements, is the basis of a successful range of linear and 2-D arrays. However, other technologies will compete for cost effectiveness in large

Rex Watton

1994-01-01

278

Active-Passive Hybrid Adaptive Structures for Vibration Controls -- An Integrated Approach.  

National Technical Information Service (NTIS)

The objective of this research is to develop, validate and evaluate novel active-passive hybrid adaptive structures for real-time vibration suppressions. These structures could have the advantages of both the passive (stable, low power requirement, tail-s...

K. Wang

2000-01-01

279

Integrated Backup Topology Control and Routing of Obscured Traffic in Hybrid RF\\/FSO Networks  

Microsoft Academic Search

We propose a framework for providing instanta- neous backup to traffic in a hybrid RF\\/FSO mesh network. Free Space Optical (FSO) links have high bandwidth and security, making them suitable for use in backbone networks. RF links have low bandwidth, but offer high reliability in conditions where FSO links are obscured. Thus, RF links are primarily used to provide instantaneous

Abhishek Kashyap; Anuj Rawat; Mark A. Shayman

2006-01-01

280

A hybrid approach to protein folding problem integrating constraint programming with local search  

Microsoft Academic Search

Background: The protein folding problem remains one of the most challenging open problems in computational biology. Simplified models in terms of lattice structure and energy function have been proposed to ease the computational hardness of this optimization problem. Heuristic search algorithms and constraint programming are two common techniques to approach this problem. The present study introduces a novel hybrid approach

Abu Zafer M. Dayem Ullah; Kathleen Steinhöfel

2010-01-01

281

Integrated Control Platform with Load Balancing Algorithm in Hybrid Optical Wireless Networks  

Microsoft Academic Search

In this paper we cover the problem of load balancing in terms of optimum cell selection and wireless channel condition in the hybrid optical wireless network. For a given set of multimedia users with minimum quality of service requirements and a set of best effort users we find the optimum resource allocation that guarantees services for the users and maximizes

Ying Yan; Lars Dittmann; Shing-Wa Wong; Leonid G. Kazovsky

2009-01-01

282

Integration of Xantrex HY-100 Hybrid Inverter with an AC Induction Wind Turbine.  

National Technical Information Service (NTIS)

Several issues must be addressed before solid-state inverters can be used in wind-diesel systems with larger wind turbines. This project addresses those issues by using a commercial hybrid inverter designed for PV-diesel systems and modifying the inverter...

D. Corbus C. Newcomb S. Friedly

2003-01-01

283

Integrating linkage and radiation hybrid mapping data for bovine chromosome 15  

Microsoft Academic Search

BACKGROUND: Bovine chromosome (BTA) 15 contains a quantitative trait loci (QTL) for meat tenderness, as well as several breaks in synteny with human chromosome (HSA) 11. Both linkage and radiation hybrid (RH) maps of BTA 15 are available, but the linkage map lacks gene-specific markers needed to identify genes underlying the QTL, and the gene-rich RH map lacks associations with

Warren M Snelling; Mathieu Gautier; John W Keele; Timothy PL Smith; Roger T Stone; Gregory P Harhay; Gary L Bennett; Naoya Ihara; Akiko Takasuga; Haruko Takeda; Yoshikazu Sugimoto; André Eggen

2004-01-01

284

A learning approach to integration of layers of a hybrid control architecture  

Microsoft Academic Search

Hybrid deliberative-reactive control architectures are a popular and effective approach to the control of robotic navigation applications. However, the design of said architec- tures is difficult, due to the fundamental differences in the design of the reactive and deliberative layers of the architecture. We propose a novel approach to improving system-level per- formance of said architectures, by improving the deliberative

Matthew Powers; Tucker R. Balch

2009-01-01

285

A High-Resolution Cat Radiation Hybrid and Integrated FISH Mapping Resource for Phylogenomic Studies across Felidae  

PubMed Central

We describe the construction of a high-resolution radiation hybrid (RH) map of the domestic cat genome, which includes 2,662 markers, translating to an estimated average intermarker distance of 939 kilobases (Kb). Targeted marker selection utilized the recent feline 1.9x genome assembly, concentrating on regions of low marker density on feline autosomes and the X chromosome, in addition to regions flanking interspecies chromosomal breakpoints. Average gap (breakpoint) size between cat-human ordered conserved segments is less than 900 Kb. The map was used for a fine-scale comparison of conserved syntenic blocks with the human and canine genomes. Corroborative fluorescence in situ hybridization (FISH) data were generated using 129 domestic cat BAC-clones as probes, providing independent confirmation of the long-range correctness of the map. Cross-species hybridization of BAC probes on divergent felids from the genera Profelis (serval) and Panthera (snow leopard) provides further evidence for karyotypic conservation within felids, and demonstrates the utility of such probes for future studies of chromosome evolution within the cat family and in related carnivores. The integrated map constitutes a comprehensive framework for identifying genes controlling feline phenotypes of interest, and to aid in assembly of a higher coverage feline genome sequence.

Davis, Brian W.; Raudsepp, Terje; Wilkerson, Alison J. Pearks; Agarwala, Richa; Schaffer, Alejandro A.; Houck, Marlys; Ryder, Oliver A.; Chowdhdary, Bhanu P.; Murphy, William J.

2008-01-01

286

Combined Monte Carlo and path-integral method for simulated library of time-resolved reflectance curves from layered tissue models  

NASA Astrophysics Data System (ADS)

Monte Carlo (MC) simulations are considered the "gold standard" for mathematical description of photon transport in tissue, but they can require large computation times. Therefore, it is important to develop simple and efficient methods for accelerating MC simulations, especially when a large "library" of related simulations is needed. A semi-analytical method involving MC simulations and a path-integral (PI) based scaling technique generated time-resolved reflectance curves from layered tissue models. First, a zero-absorption MC simulation was run for a tissue model with fixed scattering properties in each layer. Then, a closed-form expression for the average classical path of a photon in tissue was used to determine the percentage of time that the photon spent in each layer, to create a weighted Beer-Lambert factor to scale the time-resolved reflectance of the simulated zero-absorption tissue model. This method is a unique alternative to other scaling techniques in that it does not require the path length or number of collisions of each photon to be stored during the initial simulation. Effects of various layer thicknesses and absorption and scattering coefficients on the accuracy of the method will be discussed.

Wilson, Robert H.; Vishwanath, Karthik; Mycek, Mary-Ann

2009-02-01

287

Integrated Solid/Nanoporous Copper/Oxide Hybrid Bulk Electrodes for High-performance Lithium-Ion Batteries  

NASA Astrophysics Data System (ADS)

Nanoarchitectured electroactive materials can boost rates of Li insertion/extraction, showing genuine potential to increase power output of Li-ion batteries. However, electrodes assembled with low-dimensional nanostructured transition metal oxides by conventional approach suffer from dramatic reductions in energy capacities owing to sluggish ion and electron transport kinetics. Here we report that flexible bulk electrodes, made of three-dimensional bicontinuous nanoporous Cu/MnO2 hybrid and seamlessly integrated with Cu solid current collector, substantially optimizes Li storage behavior of the constituent MnO2. As a result of the unique integration of solid/nanoporous hybrid architecture that simultaneously enhances the electron transport of MnO2, facilitates fast ion diffusion and accommodates large volume changes on Li insertion/extraction of MnO2, the supported MnO2 exhibits a stable capacity of as high as ~1100 mA h g-1 for 1000 cycles, and ultrahigh charge/discharge rates. It makes the environmentally friendly and low-cost electrode as a promising anode for high-performance Li-ion battery applications.

Hou, Chao; Lang, Xing-You; Han, Gao-Feng; Li, Ying-Qi; Zhao, Lei; Wen, Zi; Zhu, Yong-Fu; Zhao, Ming; Li, Jian-Chen; Lian, Jian-She; Jiang, Qing

2013-10-01

288

Integrated Solid/Nanoporous Copper/Oxide Hybrid Bulk Electrodes for High-performance Lithium-Ion Batteries  

PubMed Central

Nanoarchitectured electroactive materials can boost rates of Li insertion/extraction, showing genuine potential to increase power output of Li-ion batteries. However, electrodes assembled with low-dimensional nanostructured transition metal oxides by conventional approach suffer from dramatic reductions in energy capacities owing to sluggish ion and electron transport kinetics. Here we report that flexible bulk electrodes, made of three-dimensional bicontinuous nanoporous Cu/MnO2 hybrid and seamlessly integrated with Cu solid current collector, substantially optimizes Li storage behavior of the constituent MnO2. As a result of the unique integration of solid/nanoporous hybrid architecture that simultaneously enhances the electron transport of MnO2, facilitates fast ion diffusion and accommodates large volume changes on Li insertion/extraction of MnO2, the supported MnO2 exhibits a stable capacity of as high as ~1100?mA h g?1 for 1000 cycles, and ultrahigh charge/discharge rates. It makes the environmentally friendly and low-cost electrode as a promising anode for high-performance Li-ion battery applications.

Hou, Chao; Lang, Xing-You; Han, Gao-Feng; Li, Ying-Qi; Zhao, Lei; Wen, Zi; Zhu, Yong-Fu; Zhao, Ming; Li, Jian-Chen; Lian, Jian-She; Jiang, Qing

2013-01-01

289

Integrated Solid/Nanoporous Copper/Oxide Hybrid Bulk Electrodes for High-performance Lithium-Ion Batteries.  

PubMed

Nanoarchitectured electroactive materials can boost rates of Li insertion/extraction, showing genuine potential to increase power output of Li-ion batteries. However, electrodes assembled with low-dimensional nanostructured transition metal oxides by conventional approach suffer from dramatic reductions in energy capacities owing to sluggish ion and electron transport kinetics. Here we report that flexible bulk electrodes, made of three-dimensional bicontinuous nanoporous Cu/MnO2 hybrid and seamlessly integrated with Cu solid current collector, substantially optimizes Li storage behavior of the constituent MnO2. As a result of the unique integration of solid/nanoporous hybrid architecture that simultaneously enhances the electron transport of MnO2, facilitates fast ion diffusion and accommodates large volume changes on Li insertion/extraction of MnO2, the supported MnO2 exhibits a stable capacity of as high as ~1100?mA h g(-1) for 1000 cycles, and ultrahigh charge/discharge rates. It makes the environmentally friendly and low-cost electrode as a promising anode for high-performance Li-ion battery applications. PMID:24096928

Hou, Chao; Lang, Xing-You; Han, Gao-Feng; Li, Ying-Qi; Zhao, Lei; Wen, Zi; Zhu, Yong-Fu; Zhao, Ming; Li, Jian-Chen; Lian, Jian-She; Jiang, Qing

2013-10-07

290

ENHANCED COD AND NUTRIENT REMOVAL EFFICIENCY IN A HYBRID INTEGRATED FIXED FILM ACTIVATED SLUDGE PROCESS  

Microsoft Academic Search

Nowadays, innovative processes especially processes with integrated growth (combined attached and suspended growth) such as moving bed biofilm reactor (MBBR) and integrated fixed film activated Sludge (IFAS) are being used successfully for new construction and upgrading existing wastewater treatment plants. Increasing the hydraulic capacity, COD and nutrients removal from the effluent are the two main targets of applying these processes.

A. A. AZIMI; B. HOOSHYARI; N. MEHRDADI; G. H. NABI BIDHENDI

291

Novel Framework of Integrated Security and Safety System Using Hybrid Network Technology  

Microsoft Academic Search

Advancement in micro-electro mechanical system (MEMS) that integrate mechanical system, sensor, actuator, and electronics has contributed to significant improvement of automation system including security and safety system. This paper will propose a framework of integrated security and safety system that combines microembedded system and computer based system. The framework is designed and developed based on conceptual model of security and

Edi Saputra; K. A. Bakar; H. Herman; S. Hassan

2009-01-01

292

Cost-effective monolithic and hybrid integration for metro and long-haul applications  

NASA Astrophysics Data System (ADS)

Today's telecommunication market is characterized by conservative business practices: tight management of costs, low risk investing and incremental upgrades, rather than the more freewheeling approach taken a few years ago. Optimizing optical components for the current and near term market involves substantial integration, but within particular bounds. The emphasis on evolution, in particular, has led to increased standardization of functions and so created extensive opportunities for integrated product offerings. The same standardization that enables commercially successful integrated functions also changes the competitive environment, and changes the emphasis for component development; shifting the innovation priority from raw performance to delivering the most effective integrated products. This paper will discuss, with specific examples from our transmitter, receiver and passives product families, our understanding of the issues based on extensive experience in delivering high end integrated products to the market, and the direction it drives optical components.

Clayton, Rick; Carter, Andy; Betty, Ian; Simmons, Timothy

2003-12-01

293

Integrating Adenovirus-Adeno-Associated Virus Hybrid Vectors Devoid of All Viral Genes  

Microsoft Academic Search

Recently, we demonstrated that inverted repeat sequences inserted into first-generation adenovirus (Ad) vector genomes mediate precise genomic rearrangements resulting in vector genomes devoid of all viral genes that are efficiently packaged into functional Ad capsids. As a specific application of this finding, we generated adenovirus-adeno-associated virus (AAV) hybrid vectors, first-generation Ad vectors containing AAV inverted terminal repeat sequences (ITRs) flanking

DIRK S. STEINWAERDER; CHERYL A. CARLSON; MARK A. KAY

1999-01-01

294

Integration of Xantrex HY-100 Hybrid Inverter with an AC Induction Wind Turbine  

Microsoft Academic Search

Several issues must be addressed before solid-state inverters can be used in wind-diesel systems with larger wind turbines. This project addresses those issues by using a commercial hybrid inverter designed for PV-diesel systems and modifying the inverter for use with an AC induction wind turbine. Another approach would have entailed building an inverter specifically for use with an AC induction

D. Corbus; C. Newcomb; S. Friedly

2003-01-01

295

Volume-Surface Integral Equations with hybrid curl-conforming and divergence-conforming basis functions  

Microsoft Academic Search

In this paper, the VSIE solved by a hybrid curl-conforming and divergence-conforming basis functions is presented. In this method, new EFIEs are formed first. Then curlconforming edge basis functions are used for the VIE with the electric field as the unknowns and divergence-conforming edge basis functions are used for the SIE on PEC surfaces with the surface electric current as

Xiande Cao; Cai-Cheng Lu

2010-01-01

296

Integrated Power Electronics Interface for Plug-In Hybrid Electric Vehicle Applications  

Microsoft Academic Search

In Plug-In Hybrid Electric Vehicles (PHEVs), the battery system would be recharged from the AC grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an advanced power electronics interface (APEI) for PHEV applications, which mainly comprises a Bidirectional Multi-Device Interleaved Converter (BMDIC) and Eight-Switch Inverter (ESI), in order

Omar Hegazy; Joeri Van Mierlo; Philippe Lataire; Mohamed El Baghdadi

2012-01-01

297

Fluorescent In Situ Hybridization to Detect Transgene Integration into Plant Genomes  

NASA Astrophysics Data System (ADS)

Fluorescent chromosome analysis technologies have advanced our understanding of genome organization during the last 30 years and have enabled the investigation of DNA organization and structure as well as the evolution of chromosomes. Fluorescent chromosome staining allows even small chromosomes to be visualized, characterized by their composition and morphology, and counted. Aneuploidies and polyploidies can be established for species, breeding lines, and individuals, including changes occurring during hybridization or tissue culture and transformation protocols. Fluorescent in situ hybridization correlates molecular information of a DNA sequence with its physical location on chromosomes and genomes. It thus allows determination of the physical position of sequences and often is the only means to determine the abundance and distribution of DNA sequences that are difficult to map with any other molecular method or would require segregation analysis, in particular multicopy or repetitive DNA. Equally, it is often the best way to establish the incorporation of transgenes, their numbers, and physical organization along chromosomes. This chapter presents protocols for probe and chromosome preparation, fluorescent in situ hybridization, chromosome staining, and the analysis of results.

Schwarzacher, Trude

298

Hybrid silicon-plasmonics: efficient waveguide interfacing for low-loss integrated switching components  

NASA Astrophysics Data System (ADS)

We present a thorough numerical investigation of end-fire coupling between dielectric-loaded surface plasmon polariton (DLSPP) and compact rib/wire silicon-on-insulator (SOI) waveguides. Simulations are based on the three-dimensional vector finite element method. The interface geometrical parameters leading to optimum performance, i.e., maximum coupling efficiency or, equivalently, minimum insertion loss (IL), are identified. We show that coupling efficiencies as high as 85 % are possible. In addition, we quantify the fabrication tolerances about the optimum parameter values. In the same context, we assess the effect of a metallic stripe gap and that of a horizontal offset between waveguides on insertion loss. Finally, we demonstrate that by benefiting form the low-loss coupling between the two waveguides, hybrid silicon-plasmonic 2 x 2 thermo-optic switching elements can outperform their all-plasmonic counterparts in terms of IL. Specifically, we examine two hybrid SOI-DLSPP switching elements, namely, a Mach-Zehnder Interferometer (MZI) and a Multi-Mode-Interference (MMI) switch. In particular, in the MZI case the IL improvement compared to the all-plasmonic counterpart is 4.5 dB. Moreover, the proposed hybrid components maintain the high extinction ratio, small footprint, and efficient tuning traits of plasmonic technology.

Tsilipakos, Odysseas; Pitilakis, Alexandros; Kriezis, Emmanouil E.

2012-05-01

299

Calculation of stress intensity factors for an interfacial crack between dissimilar anisotropic media, using a hybrid element method and the mutual integral  

Microsoft Academic Search

Using Beom and Atluri’s complete eigen-function solutions for stresses and displacements near the tip of an interfacial crack between dissimilar anisotropic media, a hybrid crack tip finite-element is developed. This element, as well as a mutual integral method are used to determine the stress intensity factors for an interfacial crack between dissimilar anisotropic media. The hybrid element has, for its

W. T. Chow; H. G. Beom; S. N. Atluri

1995-01-01

300

HORIZONTAL HYBRID SOLAR LIGHT PIPE: AN INTEGRATED SYSTEM OF DAYLIGHT AND ELECTRIC LIGHT  

EPA Science Inventory

This project will test the feasibility of an advanced energy efficient perimeter lighting system that integrates daylighting, electric lighting, and lighting controls to reduce electricity consumption. The system is designed to provide adequate illuminance levels in deep-floor...

301

Design and Realization of a High-Performance Integrated Attitude Determination System and Hybrid Simulation  

Microsoft Academic Search

A high-performance integrated attitude determination system based on multi-sensor is proposed and implemented, which is suitable for high resolution of ground stability and agile mobile observation of the new generation earth observation micro-satellites. This system includes the sensitive subsystem, the signal collecting and preprocessing subsystem and the comprehensive processing subsystem. The sensitive subsystem is integrated by four types of sensitive

Wei Quan; Liang Xu; Yangbin Ou

2011-01-01

302

New integration scheme of GPS-INS hybrid navigation system for maneuvering spacecraft  

NASA Astrophysics Data System (ADS)

Integration schemes of the GPS with INS are considered. In the conventional navigation scheme, information from INS is usually used in the form of velocity-aiding signal to the receiver-tracking loops. In this paper, a new integration scheme is proposed which performs more effective information exchange so that it is more tolerant to RF interferences and unmodeled INS errors than the conventional scheme. These results are obtained from theoretical analyses and confirmed by computer simulations including GPS receiver dynamics.

Tanabe, T.; Harigae, M.; Koyama, H.

303

Homodyne laser Doppler vibrometer on silicon-on-insulator with integrated 90 degree optical hybrids.  

PubMed

A miniaturized homodyne laser Doppler vibrometer (LDV) with a compact 90° optical hybrid is experimentally demonstrated on a CMOS compatible silicon-on-insulator (SOI) platform. Optical components on this platform usually have inadequate suppressions of spurious reflections, which significantly influence the performance of the LDV. Numerical compensation methods are implemented to effectively decrease the impact of these spurious reflections. With the help of these compensation methods, measurements for both super-half-wavelength and sub-half-wavelength vibrations are demonstrated. Results show that the minimal detectable velocity is around 1.2 ?m/s. PMID:23736586

Li, Yanlu; Baets, Roel

2013-06-01

304

A family of time-staggered schemes for integrating hybrid DPD models for polymers: Algorithms and applications  

SciTech Connect

We propose new schemes for integrating the stochastic differential equations of dissipative particle dynamics (DPD) in simulations of dilute polymer solutions. The hybrid DPD models consist of hard potentials that describe the microscopic dynamics of polymers and soft potentials that describe the mesoscopic dynamics of the solvent. In particular, we develop extensions to the velocity-Verlet and Lowe's approaches - two representative DPD time-integrators - following a subcycling procedure whereby the solvent is advanced with a timestep much larger than the one employed in the polymer time-integration. The introduction of relaxation parameters allows optimization studies for accuracy while maintaining the low computational complexity of standard DPD algorithms. We demonstrate through equilibrium simulations that a 10-fold gain in efficiency can be obtained with the time-staggered algorithms without loss of accuracy compared to the non-staggered schemes. We then apply the new approach to investigate the scaling response of polymers in equilibrium as well as the dynamics of {lambda}-phage DNA molecules subjected to shear.

Symeonidis, Vasileios [Division of Applied Mathematics, Brown University, 182 George Street, Box F, Providence, RI 02912 (United States); Karniadakis, George Em [Division of Applied Mathematics, Brown University, 182 George Street, Box F, Providence, RI 02912 (United States)]. E-mail: gk@dam.brown.edu

2006-10-10

305

Integrated hybrid vibration isolator with feedforward compensation for fast high-precision positioning X/Y tables  

NASA Astrophysics Data System (ADS)

The design, realization and control technologies of a high-performance hybrid microvibration isolator for ultra-high-precision high-speed moving X/Y tables are presented in this paper—the novel isolator with integrated passive-active high level of damping. The passive damping was implemented using air-springs in both vertical and horizontal directions, with parallel linear motors in two directions to realize the active damping and the positioning functions. It is an actual hybrid isolation system because its air-spring can also be controlled through the pneumatic loop. The isolation servo system also has fast positioning capability via the feedforward compensation for the moving tables. Compared with the conventional filtered reference type control algorithms that rely on the assumption for the adaptive filter and the controlled system, in which the disturbance is estimated from the residual signal, the feedforward compensation here shows high effectiveness of vibration isolation and high-precision positioning performance for its platform. The performance of feedforward compensation has been enhanced via an efficient state estimation adaptive algorithm, the fast Kalman filter. Finally, experimental demonstration has been shown for the prototype system and the results have verified the effectiveness of the proposed isolator system design and the adaptive control algorithm for substantially enhanced damping of the platform system with the moving X/Y tables.

Yan, T. H.; Pu, H. Y.; Chen, X. D.; Li, Q.; Xu, C.

2010-06-01

306

An Integrated PCR Colony Hybridization Approach to Screen cDNA Libraries for Full-Length Coding Sequences  

PubMed Central

Background cDNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) is a commonly used technique for genome-wide expression analysis that does not require prior sequence knowledge. Typically, quantitative expression data and sequence information are obtained for a large number of differentially expressed gene tags. However, most of the gene tags do not correspond to full-length (FL) coding sequences, which is a prerequisite for subsequent functional analysis. Methodology A medium-throughput screening strategy, based on integration of polymerase chain reaction (PCR) and colony hybridization, was developed that allows in parallel screening of a cDNA library for FL clones corresponding to incomplete cDNAs. The method was applied to screen for the FL open reading frames of a selection of 163 cDNA-AFLP tags from three different medicinal plants, leading to the identification of 109 (67%) FL clones. Furthermore, the protocol allows for the use of multiple probes in a single hybridization event, thus significantly increasing the throughput when screening for rare transcripts. Conclusions The presented strategy offers an efficient method for the conversion of incomplete expressed sequence tags (ESTs), such as cDNA-AFLP tags, to FL-coding sequences.

Ardiles-Diaz, Wilson; Geelen, Danny; Goossens, Alain

2011-01-01

307

Integrative self-assembly of functional hybrid nanoconstructs by inorganic wrapping of single biomolecules, biomolecule arrays and organic supramolecular assemblies  

NASA Astrophysics Data System (ADS)

Synthesis of functional hybrid nanoscale objects has been a core focus of the rapidly progressing field of nanomaterials science. In particular, there has been significant interest in the integration of evolutionally optimized biological systems such as proteins, DNA, virus particles and cells with functional inorganic building blocks to construct mesoscopic architectures and nanostructured materials. However, in many cases the fragile nature of the biomolecules seriously constrains their potential applications. As a consequence, there is an on-going quest for the development of novel strategies to modulate the thermal and chemical stabilities, and performance of biomolecules under adverse conditions. This feature article highlights new methods of ``inorganic molecular wrapping'' of single or multiple protein molecules, individual double-stranded DNA helices, lipid bilayer vesicles and self-assembled organic dye superstructures using inorganic building blocks to produce bio-inorganic nanoconstructs with core-shell type structures. We show that spatial isolation of the functional biological nanostructures as ``armour-plated'' enzyme molecules or polynucleotide strands not only maintains their intact structure and biochemical properties, but also enables the fabrication of novel hybrid nanomaterials for potential applications in diverse areas of bionanotechnology.

Patil, Avinash J.; Li, Mei; Mann, Stephen

2013-07-01

308

Interfacial Behavior in Polyelectrolyte Blends: Hybrid Liquid-State Integral Equation and Self-Consistent Field Theory Study  

NASA Astrophysics Data System (ADS)

Polyelectrolytes and electrolyte solutions are known to demonstrate a rich array of phase behaviors due to the effects of long-ranged interactions inherent in Coulombic attractions and repulsions. While there is a wealth of literature examining these materials to provide some physical insight into their thermodynamics, all of these methods make strong approximations with regards to the nature of the ionic component. In this investigation we develop a hybrid liquid-state integral equation and self-consistent field theory numerical theory, and systematically demonstrate the ramifications on local ion structure on the overall thermodynamics of segregated polymer blends. We show effects on phase separation such as suppression due to hard sphere interactions and enhancement due to ion cohesion that are not described using traditional Poisson-Boltzmann mean-field theory.

Sing, Charles E.; Zwanikken, Jos W.; de la Cruz, Monica Olvera

2013-10-01

309

Integrated magnetostratigraphy and biostratigraphy of the upper Pliocene-lower Pleistocene from the Monte Singa and Crotone areas in Calabria, Italy  

Microsoft Academic Search

The results of a detailed magnetostratigraphic and biostratigraphic study of late Pliocene to early Pleistocene marine\\u000amarl sequences from the Monte Singa and Crotone areas in Calabria, Italy are presented.\\u000aThe magnetostratigraphy from the Monte Singa sequence ranges from below the Gauss\\/Matuyama boundary up to and\\u000aincluding the lower Olduvai boundary. Normal polarities at a level corresponding to isotope stage

J. D. A. Zijderveld; F. J. Hilgen; C. G. Langereis; P. J. J. M. Verhallen; W. J. Zachariasse

1991-01-01

310

The Late Albian to Early Cenomanian succession at Mont Risou near Rosans (Drôme, SE France): an integrated study (ammonites, inoceramids, planktonic foraminifera, nannofossils, oxygen and carbon isotopes)  

Microsoft Academic Search

The Second International Symposium on Cretaceous stage boundaries held in Brussels from September 8-14 1995 reached a preliminary agreement on the definition of the base of the Cenomanian stage as the first occurrence of the planktonic foraminiferanRotalipora globotruncanoidesSigal, with a section at Mont Risou near Rosans, Drôme, SE France as the global reference section, Sigal, with a section at Mont

A. S. Gale; W. J. Kennedy; J. A. Burnett; M. Caron; B. E. Kidd

1996-01-01

311

Proportional–integral controller based small-signal analysis of hybrid distributed generation systems  

Microsoft Academic Search

The large band variation in the wind speed and unpredictable solar radiation causes remarkable fluctuations of output power in offshore wind and photovoltaic system respectively, which leads to large deviation in the system frequency. In this context, to minimize the deviation in frequency, this paper presents integration of different energy resources like offshore wind, photovoltaic (PV), fuel cell (FC) and

Prakash K. Ray; Soumya R. Mohanty; Nand Kishor

2011-01-01

312

Transient analysis of integrated solar\\/diesel hybrid power system using MATLAB Simulink  

Microsoft Academic Search

This paper presents Matlab simulation the dynamic behavior of small autonomous power system with solar and diesel power sources. The solar power system and the diesel generator operate in parallel. It is more cost effective than a diesel generator acting alone. For the effective integration of the solar power into the power system, a method for controlling the Inverter's operation

Takyin Taky Chan

313

Managing Change in an Integrated School--A Hong Kong Hybrid Experience  

ERIC Educational Resources Information Center

Following the world trend of inclusion in education, many schools in Hong Kong have started including students with special needs in the regular classrooms. Given the unique educational context of Hong Kong as "East meets West", and given that inclusion is essentially a concept from the West, this paper argues that Hong Kong's integration has its…

Yee, Pattie Luk Fong Yuk

2005-01-01

314

Hybrid Dyadic - MPIE Integral Equation Analysis of Passive Microwave Devices in Layered Media  

Microsoft Academic Search

Integral equation modeling of electromagnetic radiation and interference phenomena in planar circuits and antennas offers exact solutions usually at the cost of excessive computation time, especially when arbitrary 3D conducting surfaces are involved. However, we will restrict the geometry to the 2.5D case : this assumes that only horizontal current sheets parallel to the layer structure and vertical conducting surfaces

Mark Vrancken; Guy A. E. Vandenbosch

2001-01-01

315

Design of integrated electro-hydraulic power unit for hybrid mobile working machines  

Microsoft Academic Search

A high power density integrated non-overlapping concentrated tooth winding synchronous machine with embedded permanent magnets for a hydraulic motor-pump is designed. Direct liquid cooling with the working fluid itself is implemented. Aspects of immersing the motor into hydraulic oil for cooling purposes are discussed. FEM modelling of PM eddy-current losses and static temperature evaluation are performed.

Pavel Ponomarev; Maria Polikarpova; Olli Heinikainen; Juha Pyrhonen

2011-01-01

316

Hybrid modeling and optimization of VLSI interconnects for signal integrity using neuroGenetic algorithm  

Microsoft Academic Search

The number of interconnects in any VLSI system is very large. During high speed interconnect analysis, interconnect effects like signal delay, crosstalk, ground bound noise, ringing and distortion become more significant. These interconnect effects, also known as signal integrity effects, must be taken in to account during digital circuit design. It is predicted that interconnects will be responsible for nearly

N. Suresh Kumar; G. V. Subramanian; S. Raju; V. A. Kumar

2006-01-01

317

Production engineering measure for hybrid integrated circuits for fuze applications, volume 1  

Microsoft Academic Search

The initial review of the integrated arming and firing circuits indicated a need for revision to the specifications, in regard to the plastic packaging. Thick film processing was selected as the method to produce the devices. A computerized testing system was designed to perform the electrical testing on the devices. Packaging problems occurred during the final lot of engineering samples

T. Sciacca; H. Brandt

1974-01-01

318

The prescribing clinical health psychologist: a hybrid skill set in the new era of integrated healthcare.  

PubMed

The prescribing clinical health psychologist brings together in one individual a combination of skills to create a hybrid profession that can add value to any healthcare organization. This article addresses the high demand for mental health services and the inequitable distribution of mental health practitioners across the nation. The close link between physical and mental health and evidence that individuals in psychological distress often enter the mental health system via primary care medical clinics is offered as background to a discussion of the author's work as a commissioned officer of the U.S. Public Health Service assigned to the Chaparral Medical Center of La Clinica de Familia, Inc. near the U.S.-Mexico border. The prescribing clinical health psychologist in primary care medical settings is described as a valuable asset to the future of professional psychology. PMID:23179075

McGuinness, Kevin M

2012-12-01

319

Monitoring Protein-Protein Interactions between the Mammalian Integral Membrane Transporters and PDZ-interacting Partners Using a Modified Split-ubiquitin Membrane Yeast Two-hybrid System  

Microsoft Academic Search

PDZ-binding motifs are found in the C-terminal tails of numerous integral membrane proteins where they medi- ate specific protein-protein interactions by binding to PDZ-containing proteins. Conventional yeast two-hybrid screens have been used to probe protein-protein interac- tions of these soluble C termini. However, to date no in vivo technology has been available to study interactions between the full-length integral membrane

Serge M. Gisler; Saranya Kittanakom; Daniel Fuster; Victoria Wong; Mia Bertic; Tamara Radanovic; Randy A. Hall; Heini Murer; Jurg Biber; Daniel Markovich; Orson W. Moe; Igor Stagljar

2008-01-01

320

A Hybrid System Integrating a Wavelet and TSK Fuzzy Rules for Stock Price Forecasting  

Microsoft Academic Search

Abstract—The prediction of future time series values based on past and present information is very useful and necessary for var- ious industrial and financial applications. In this study, a novel approach that integrates the wavelet and Takagi–Sugeno–Kang (TSK)-fuzzy-rule-based systems for stock price prediction is devel- oped. A wavelet transform using the Haar wavelet will be applied to decompose the time

Pei-Chann Chang; Chin-Yuan Fan

2008-01-01

321

A hybrid MCMD integrated borda function and gray rational analysis for 3PLs selection  

Microsoft Academic Search

In this paper, we propose a two-stage method based on Borda function theory (BF) and gray rational analysis (GRA) for logistic outsourcing decision-making. In the first stage, we used the social welfare function theory to select potential providers from 3PLs (third part logistic suppliers) set. Then, modified GRA theory that integrates ANP will be used for final selection, emphasizing the

Jie Cao; Guo Cao; Wei-wei Wang

2007-01-01

322

Hybrid Integration of End-to-End Optical Interconnects on Printed Circuit Boards  

Microsoft Academic Search

This paper discusses the integration of an end-to-end optical interconnect testbed on printed circuit boards using inexpensive off-the-shelf, bare die, optoelectronic components. We developed a process for efficient and simultaneous in-plane optical coupling between edge emitting laser and waveguides, and between photodetector and waveguide. We demonstrated an optically smooth buffer layer separating the printed circuit layer from the optical transport

Zhaoran Rena Huang; Daniel Guidotti; Lixi Wan; Yin-Jung Chang; Jianjun Yu; Jin Liu; Hung-Fei Kuo; Gee-Kung Chang; Fuhan Liu; Rao R. Tummala

2007-01-01

323

Hybrid SPECT-CT: Integration of CT coronary artery calcium scoring and angiography with myocardial perfusion  

Microsoft Academic Search

A natural extension of current imaging paradigms for diagnosing coronary artery disease may well be the integration of CT\\u000a with myocardial perfusion single-photon CT (SPECT). Although there is a wealth of clinical information regarding the utility\\u000a of SPECT, the value of CT in the cardiology arena has only recently been explored. CT has the advantage of detecting coronary\\u000a atherosclerosis at

John J. Mahmarian

2007-01-01

324

Hybrid integration approach of VCSELs for miniaturized optical deflection of microparticles  

NASA Astrophysics Data System (ADS)

In recent years, optical manipulation has gained increasing interest, especially in combination with microfluidics. This combination offers promising tools for a fast and cost-effective sample analysis and manipulation. The contamination-free handling of micrometer-sized particles without any mechanical contact is an attractive tool for biology and medicine. VCSELs (vertical-cavity surface-emitting lasers) are an excellent choice for the trapping lasers, offering the opportunity of parallel particle manipulation by using two-dimensional VCSEL arrays, and of miniaturization by means of integration. In this paper, we present two novel concepts for the realization of the so-called integrated optical trap, resembling a strongly miniaturized version of the typically bulky setup of an optical trap. For this purpose, AlGaAs-GaAs-based VCSEL arrays with a very small device pitch were fabricated. We show the realization of integration-ready particle manipulation devices, both with top-emitting and with bottom-emitting densely packed VCSEL arrays. The smallest pitch of 18 ?m is achieved with bottom-emitting VCSEL arrays, having mesa diameters of only 16 ?m.

Bergmann, Anna; Khan, Niazul Islam; Martos Calahorro, Jose Antonio; Wahl, Dietmar; Michalzik, Rainer

2012-05-01

325

Integration of Ecogpt and SV40 early region sequences into human chromosome 17: a dominant selection system in whole cell and microcell human-mouse hybrids.  

PubMed

The dominant selectable gene, Ecogpt, has been introduced, by the calcium phosphate precipitation technique, into normal human fibroblasts, along with the SV40 early region genes. In one transfectant clone, integration of these sequences into human chromosome 17 was demonstrated by the construction of human-mouse somatic cell hybrids, selected for by growth in medium containing mycophenolic acid and xanthine. A whole cell hybrid, made between the human transfectant and a mouse L cell, was used as donor of the Ecogpt-carrying human chromosome 17 to 'tribrids' growing in suspension, made by whole cell fusion between a mouse thymoma cell line, and to microcell hybrids made with a mouse teratocarcinoma cell line. Two tribrids contained karyotypically normal human chromosomes 17 and a small number of other human chromosomes, while a third tribrid had a portion of the long arm of chromosome 17 translocated to mouse as its only human genetic material. Two independent microcell hybrids contained a normal chromosome 17 and no other human chromosome on a mouse teratocarcinoma background. These experiments demonstrate the ability to construct human-mouse somatic cell hybrids using a dominant selection system. By applying this approach it should be possible to select for a wide range of different human chromosomes in whole cell and microcell hybrids. In particular, transfer of single human chromosomes to mouse teratocarcinoma cells will allow examination of developmentally regulated human gene sequences after differentiation of such hybrids. PMID:11892815

Tunnacliffe, A; Parkar, M; Povey, S; Bengtsson, B O; Stanley, K; Solomon, E; Goodfellow, P

1983-01-01

326

Integration of Ecogpt and SV40 early region sequences into human chromosome 17: a dominant selection system in whole cell and microcell human-mouse hybrids.  

PubMed Central

The dominant selectable gene, Ecogpt, has been introduced, by the calcium phosphate precipitation technique, into normal human fibroblasts, along with the SV40 early region genes. In one transfectant clone, integration of these sequences into human chromosome 17 was demonstrated by the construction of human-mouse somatic cell hybrids, selected for by growth in medium containing mycophenolic acid and xanthine. A whole cell hybrid, made between the human transfectant and a mouse L cell, was used as donor of the Ecogpt-carrying human chromosome 17 to 'tribrids' growing in suspension, made by whole cell fusion between a mouse thymoma cell line, and to microcell hybrids made with a mouse teratocarcinoma cell line. Two tribrids contained karyotypically normal human chromosomes 17 and a small number of other human chromosomes, while a third tribrid had a portion of the long arm of chromosome 17 translocated to mouse as its only human genetic material. Two independent microcell hybrids contained a normal chromosome 17 and no other human chromosome on a mouse teratocarcinoma background. These experiments demonstrate the ability to construct human-mouse somatic cell hybrids using a dominant selection system. By applying this approach it should be possible to select for a wide range of different human chromosomes in whole cell and microcell hybrids. In particular, transfer of single human chromosomes to mouse teratocarcinoma cells will allow examination of developmentally regulated human gene sequences after differentiation of such hybrids. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7.

Tunnacliffe, A; Parkar, M; Povey, S; Bengtsson, B O; Stanley, K; Solomon, E; Goodfellow, P

1983-01-01

327

Production engineering measure for hybrid integrated circuits for fuze applications. Part 1: Integrated arming and firing circuit. Part 2: Precision oscillator integrated circuit  

Microsoft Academic Search

The Integrated Arming and Firing Circuit involves the fabrication of a thick film circuit substrate, and attachment of transistors and capacitor components, and packaging. The program includes actual fabrication of test samples, a production run and performance of electrical, mechanical, and environmental tests as required.

T. Sciacca; H. G. Brandt

1974-01-01

328

Integration of photoswitchable proteins, photosynthetic reaction centers and semiconductor/biomolecule hybrids with electrode supports for optobioelectronic applications.  

PubMed

Light-triggered biological processes provide the principles for the development of man-made optobioelectronic systems. This Review addresses three recently developed topics in the area of optobioelectronics, while addressing the potential applications of these systems. The topics discussed include: (i) the reversible photoswitching of the bioelectrocatalytic functions of redox proteins by the modification of proteins with photoisomerizable units or by the integration of proteins with photoisomerizable environments; (ii) the integration of natural photosynthetic reaction centers with electrodes and the construction of photobioelectrochemical cells and photobiofuel cells; and (iii) the synthesis of biomolecule/semiconductor quantum dots hybrid systems and their immobilization on electrodes to yield photobioelectrochemical and photobiofuel cell elements. The fundamental challenge in the tailoring of optobioelectronic systems is the development of means to electrically contact photoactive biomolecular assemblies with the electrode supports. Different methods to establish electrical communication between the photoactive biomolecular assemblies and electrodes are discussed. These include the nanoscale engineering of the biomolecular nanostructures on surfaces, the development of photoactive molecular wires and the coupling of photoinduced electron transfer reactions with the redox functions of proteins. The different possible applications of optobioelectronic systems are discussed, including their use as photosensors, the design of biosensors, and the construction of solar energy conversion and storage systems. PMID:22933337

Wang, Fuan; Liu, Xiaoqing; Willner, Itamar

2012-08-30

329

A mitochondrial retroplasmid integrates into mitochondrial DNA by a novel mechanism involving the synthesis of a hybrid cDNA and homologous recombination.  

PubMed

The Mauriceville and Varkud mitochondrial plasmids of Neurospora spp. are closely related, small circular DNAs that propagate via an RNA intermediate and reverse transcription. Although the plasmids ordinarily replicate autonomously, they can also integrate into mitochondrial DNA (mtDNA), yielding defective mtDNAs that in some cases cause senescence. To investigate the integration mechanism, we analyzed four cases in which the Varkud plasmid integrated into the mitochondrial small rRNA gene, three in wild-type subcultures and one in a senescent mutant. Our analysis suggests that the integrations occurred by the plasmid reverse transcriptase template switching between the plasmid transcript and internal sequences in the mitochondrial small rRNA to yield hybrid cDNAs that circularized and recombined homologously with the mtDNA. The integrated plasmid sequences are transcribed, presumably from the mitochondrial small rRNA promoters, resulting in hybrid RNAs containing the 5' segment of the mitochondrial small rRNA linked head-to-tail to the full-length plasmid transcript. Analysis of additional senescent mutants revealed three cases in which the plasmid used the same mechanism to integrate at other locations in the mtDNA. In these cases, circular variant plasmids that had incorporated a mitochondrial tRNA or tRNA-like sequence by template switching integrated by homologous recombination at the site of the corresponding tRNA or tRNA-like sequence in mtDNA. This simple integration mechanism involving template switching to generate a hybrid cDNA that integrates homologously could have been used by primitive retroelements prior to the acquisition of a specialized integration machinery. PMID:7523850

Chiang, C C; Kennell, J C; Wanner, L A; Lambowitz, A M

1994-10-01

330

A mitochondrial retroplasmid integrates into mitochondrial DNA by a novel mechanism involving the synthesis of a hybrid cDNA and homologous recombination.  

PubMed Central

The Mauriceville and Varkud mitochondrial plasmids of Neurospora spp. are closely related, small circular DNAs that propagate via an RNA intermediate and reverse transcription. Although the plasmids ordinarily replicate autonomously, they can also integrate into mitochondrial DNA (mtDNA), yielding defective mtDNAs that in some cases cause senescence. To investigate the integration mechanism, we analyzed four cases in which the Varkud plasmid integrated into the mitochondrial small rRNA gene, three in wild-type subcultures and one in a senescent mutant. Our analysis suggests that the integrations occurred by the plasmid reverse transcriptase template switching between the plasmid transcript and internal sequences in the mitochondrial small rRNA to yield hybrid cDNAs that circularized and recombined homologously with the mtDNA. The integrated plasmid sequences are transcribed, presumably from the mitochondrial small rRNA promoters, resulting in hybrid RNAs containing the 5' segment of the mitochondrial small rRNA linked head-to-tail to the full-length plasmid transcript. Analysis of additional senescent mutants revealed three cases in which the plasmid used the same mechanism to integrate at other locations in the mtDNA. In these cases, circular variant plasmids that had incorporated a mitochondrial tRNA or tRNA-like sequence by template switching integrated by homologous recombination at the site of the corresponding tRNA or tRNA-like sequence in mtDNA. This simple integration mechanism involving template switching to generate a hybrid cDNA that integrates homologously could have been used by primitive retroelements prior to the acquisition of a specialized integration machinery. Images

Chiang, C C; Kennell, J C; Wanner, L A; Lambowitz, A M

1994-01-01

331

A 10Gb/s transimpedance amplifier for hybrid integration of a Ge PIN waveguide photodiode  

NASA Astrophysics Data System (ADS)

The presented paper describes a 10 Gbps optical receiver. The transimpedance amplifier (TIA) is realized in standard 0.35 ?m SiGe BiCMOS technology. The main novelty of the presented design - investigated in the European Community project HELIOS - is the hybrid connection of the optical detector. The used Germanium photodetector will be directly mounted onto the receiver. A model of the relevant parasitics of the photodetector itself and the novel connection elements (micropads, metal vias and metal lines) is described. Based on this photodetector model an optical receiver circuit was optimized for maximum sensitivity at data rates in the range of 10 Gbps. The design combines a TIA and two limiting amplifier stages followed by a 50 ? CML-style logic-level output driver. To minimize power supply noise and substrate noise, a fully differential design is used. A dummy TIA provides a symmetrical input signal reference and a control loop is used to compensate the offset levels. The TIA is built around a common-emitter stage and features a feedback resistor of 4.2 ?. The total transimpedance of the complete receiver chain is in the range of 275 k?. The value of the active feedback resistor can be reduced via an external control voltage to adapt the design to different overall gain requirements. The two limiting amplifier stages are realized as differential amplifiers with voltage followers. The output buffer is implemented with cascode differential amplifiers. The output buffer is capable of driving a differential 50? output with a calculated output swing of 800mVp-p. Simulations show an overall bandwidth of 7.2 GHz. The lower cutoff frequency is below 60 kHz. The equivalent input noise current is 408 nA. With an estimated total photodiode responsivity of 0.5 A/W this allows a sensitivity of around - 23.1 dBm (BER = 10-9). The device operates from a single 3.3 V power supply and the TIAs and the limiting amplifier consume 32 mA.

Polzer, A.; Gaberl, W.; Swoboda, R.; Zimmermann, H.; Fedeli, J.-M.; Vivien, L.

2010-04-01

332

Field Test and Performance Verification: Integrated Active Desiccant Rooftop Hybrid System Installed in a School - Final Report: Phase 4A  

SciTech Connect

This report summarizes the results of a field verification pilot site investigation that involved the installation of a hybrid integrated active desiccant/vapor-compression rooftop heating, ventilation, and air-conditioning (HVAC) unit at an elementary school in the Atlanta Georgia area. For years, the school had experienced serious humidity and indoor air quality (IAQ) problems that had resulted in occupant complaints and microbial (mold) remediation. The outdoor air louvers of the original HVAC units had been closed in an attempt to improve humidity control within the space. The existing vapor compression variable air volume system was replaced by the integrated active desiccant rooftop (IADR) system that was described in detail in an Oak Ridge National Laboratory (ORNL) report published in 2004 (Fischer and Sand 2004). The IADR system and all space conditions have been monitored remotely for more than a year. The hybrid system was able to maintain both the space temperature and humidity as desired while delivering the outdoor air ventilation rate required by American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 62. The performance level of the IADR unit and the overall system energy efficiency was measured and found to be very high. A comprehensive IAQ investigation was completed by the Georgia Tech Research Institute before and after the system retrofit. Before-and-after data resulting from this investigation confirmed a significant improvement in IAQ, humidity control, and occupant comfort. These observations were reported by building occupants and are echoed in a letter to ORNL from the school district energy manager. The IADR system was easily retrofitted in place of the original rooftop system using a custom curb adapter. All work was completed in-house by the school's maintenance staff over one weekend. A subsequent cost analysis completed for the school district by the design engineer of record concluded that the IADR system being investigated was actually less expensive to install than other less-efficient options, most of which were unable to deliver the required ventilation while maintaining the desired space humidity levels.

Fischer, J

2005-12-21

333

Femtosecond laser polymerization of hybrid/integrated micro-optical elements and their characterization  

NASA Astrophysics Data System (ADS)

The femtosecond laser-induced multi-photon polymerization of a zirconium-silicon based sol-gel photopolymer was employed for the fabrication of a series of micro-optical elements with single and combined optical functions: convex and Fresnel lenses, gratings, solid immersion lenses on a glass slide and on the tip of an optical fiber. The microlenses were produced as polymer caps of varying radii from 10 to 90 µm. The matching of refractive indices between the polymer and substrate was exploited for the creation of composite glass-resist structures which functioned as single lenses. Using this principle, solid immersion lenses were fabricated and their performance demonstrated. The magnification of the composite solid immersion lenses corresponded to the calculated values. The surface roughness of the lenses was below ~ 30 nm, acceptable for optical applications in the visible range. In addition, the integration of micro-optical elements onto the tip of an optical fiber was demonstrated. To increase the efficiency of the 3D laser polymerization, the lenses were formed by scanning only the outer shell and polymerizing the interior by exposure to UV light.

Malinauskas, Mangirdas; Žukauskas, Albertas; Purlys, Vytautas; Belazaras, Kastytis; Momot, Andrej; Paipulas, Domas; Gadonas, Roaldas; Piskarskas, Algis; Gilbergs, Holger; Gaidukevi?i?t?, Arun?; Sakellari, Ioanna; Farsari, Maria; Juodkazis, Saulius

2010-12-01

334

Real-time hybrid simulation of a complex bridge model with MR dampers using the convolution integral method  

NASA Astrophysics Data System (ADS)

Magneto-rheological (MR) fluid dampers can be used to reduce the traffic induced vibration in highway bridges and protect critical structural components from fatigue. Experimental verification is needed to verify the applicability of the MR dampers for this purpose. Real-time hybrid simulation (RTHS), where the MR dampers are physically tested and dynamically linked to a numerical model of the highway bridge and truck traffic, provides an efficient and effective means to experimentally examine the efficacy of MR dampers for fatigue protection of highway bridges. In this paper a complex highway bridge model with 263?178 degrees-of-freedom under truck loading is tested using the proposed convolution integral (CI) method of RTHS for a semiactive structural control strategy employing two large-scale 200 kN MR dampers. The formation of RTHS using the CI method is first presented, followed by details of the various components in the RTHS and a description of the implementation of the CI method for this particular test. The experimental results confirm the practicability of the CI method for conducting RTHS of complex systems.

Jiang, Zhaoshuo; Jig Kim, Sung; Plude, Shelley; Christenson, Richard

2013-10-01

335

A compact frequency-domain photon migration system for integration into commercial hybrid small animal imaging scanners for fluorescence tomography.  

PubMed

The work presented herein describes the system design and performance evaluation of a miniaturized near-infrared fluorescence (NIRF) frequency-domain photon migration (FDPM) system with non-contact excitation and homodyne detection capability for small animal fluorescence tomography. The FDPM system was developed specifically for incorporation into a Siemens micro positron emission tomography/computed tomography (microPET/CT) commercial scanner for hybrid small animal imaging, but could be adapted to other systems. Operating at 100 MHz, the system noise was minimized and the associated amplitude and phase errors were characterized to be ±0.7% and ±0.3°, respectively. To demonstrate the tomographic ability, a commercial mouse-shaped phantom with 50 µM IRDye800CW and ??Ga containing inclusion was used to associate PET and NIRF tomography. Three-dimensional mesh generation and anatomical referencing was accomplished through CT. A third-order simplified spherical harmonics approximation (SP?) algorithm, for efficient prediction of light propagation in small animals, was tailored to incorporate the FDPM approach. Finally, the PET-NIRF target co-localization accuracy was analyzed in vivo with a dual-labeled imaging agent targeting orthotopic growth of human prostate cancer. The obtained results validate the integration of time-dependent fluorescence tomography system within a commercial microPET/CT scanner for multimodality small animal imaging. PMID:23171509

Darne, Chinmay D; Lu, Yujie; Tan, I-Chih; Zhu, Banghe; Rasmussen, John C; Smith, Anne M; Yan, Shikui; Sevick-Muraca, Eva M

2012-11-22

336

Light turning mirrors for hybrid integration of SiON-based optical waveguides and photo-detectors.  

PubMed

For hybrid integration of an optical chip with an electronic chip containing photo-diodes and processing electronics, light must be coupled from the optical to the electronic chip. This paper presents a method to fabricate quasi-total-internal-reflecting mirrors on an optical chip, placed at an angle of 45° with the chip surface, that enable 90° out-of-plane light coupling between flip-chip bonded chips. The fabrication method utilizes a metal-free, parallel process and is fully compatible with conventional fabrication of optical chips. The mirrors are created using anisotropic etching of 45° facets in a Si substrate, followed by fabrication of the optical structures. After removal of the mirror-defining Si structures by isotropic etching, the obtained interfaces between optical structure and air direct the output from optical waveguides to out-of-plane photo-detectors on the electronic chip, which is aimed to be flip-chip mounted on the optical chip. For transverse-electric (transverse-magnetic) polarization simulations predict a functional loss of 7% (15%), while 7% (18%) is measured. PMID:24104346

Civitci, F; Sengo, G; Driessen, A; Pollnau, M; Annema, A J; Hoekstra, H J W M

2013-10-01

337

Detection of Pulmonary Nodules in CT Images Based on Fuzzy Integrated Active Contour Model and Hybrid Parametric Mixture Model  

PubMed Central

The segmentation and detection of various types of nodules in a Computer-aided detection (CAD) system present various challenges, especially when (1) the nodule is connected to a vessel and they have very similar intensities; (2) the nodule with ground-glass opacity (GGO) characteristic possesses typical weak edges and intensity inhomogeneity, and hence it is difficult to define the boundaries. Traditional segmentation methods may cause problems of boundary leakage and “weak” local minima. This paper deals with the above mentioned problems. An improved detection method which combines a fuzzy integrated active contour model (FIACM)-based segmentation method, a segmentation refinement method based on Parametric Mixture Model (PMM) of juxta-vascular nodules, and a knowledge-based C-SVM (Cost-sensitive Support Vector Machines) classifier, is proposed for detecting various types of pulmonary nodules in computerized tomography (CT) images. Our approach has several novel aspects: (1) In the proposed FIACM model, edge and local region information is incorporated. The fuzzy energy is used as the motivation power for the evolution of the active contour. (2) A hybrid PMM Model of juxta-vascular nodules combining appearance and geometric information is constructed for segmentation refinement of juxta-vascular nodules. Experimental results of detection for pulmonary nodules show desirable performances of the proposed method.

Li, Bin; Chen, Kan; Tian, Lianfang; Yeboah, Yao; Ou, Shanxing

2013-01-01

338

Fabrication of a TFF-Attached WDM-Type Triplex Transceiver Module Using Silica PLC Hybrid Integration Technology  

NASA Astrophysics Data System (ADS)

An optical triplex transceiver (TRx) module, which consists of thin-film filter (TFF)-attached wavelength-division multiplexer (WDM) and photodiode (PD) carriers, has been fabricated using a silica planar lightwave circuit (PLC) hybrid integration technology. Two types of TFFs were attached to a diced sidewall of a silica-terraced PLC platform to realize the TFF-attached WDM. The PD carriers with a 45° mirror, on which receiving surface-illuminated PDs were bonded, were assembled with the PLC platform to form receiver (Rx) parts. As the main performances of the packaged TRx module, a very clear transmitter (Tx) eye pattern and minimum Rx sensitivity of -25.7 dBm were obtained under a 1.25-Gb/s Tx Rx operation for digital applications. For an analog Rx application, a module responsivity of about 0.8 A/W was achieved, and a second-order intermodulation distortion value of less than -70 dBc at an optical modulation index of 40% was obtained under a two-tone test of 400 and 450 MHz.

Han, Young-Tak; Park, Yoon-Jung; Park, Sang-Ho; Shin, Jang-Uk; Lee, Chul-Wook; Ko, Hyunsung; Baek, Yongsoon; Park, Chul-Hee; Kwon, Yoon-Koo; Hwang, Wol-Yon; Oh, Kwang-Ryong; Sung, Heekyung

2006-12-01

339

Evaporation-Induced Self-Assembly of Hybrid Bridged Silsesquioxane Film and Particulate Mesophases with Integral Organic Functionality  

SciTech Connect

Since the discovery of surfactant-templated silica mesophases, the development of organic modification schemes to impart functionality to the pore surfaces has received much attention. Most recently, using the general class of compounds referred to as bridged silsesquioxanes (RO){sub 3}Si-R{prime}-Si(OR){sub 3} (Scheme 1), three research groups have reported the formation of a new class of poly(bridgedsilsesquioxane) mesophases BSQMs with integral organic functionality. In contrast to previous hybrid mesophases where organic ligands or molecules are situated on pore surfaces, this class of materials necessarily incorporates the organic constituents into the framework as molecularly dispersed bridging ligands. Although it is anticipated that this new mesostructural organization should result in synergistic properties derived from the molecular scale mixing of the inorganic and organic components, few properties of BSQMs have been measured. In addition samples prepared to date have been in the form of granular precipitates, precluding their use in applications like membranes, fluidics, and low k dielectric films needed for all foreseeable future generations of microelectronics.

LU,YUNFENG; FAN,HONGYOU; DOKE,NILESH; LOY,DOUGLAS A.; ASSINK,ROGER A.; LAVAN,DAVID A.; BRINKER,C. JEFFREY

2000-06-12

340

A compact frequency-domain photon migration system for integration into commercial hybrid small animal imaging scanners for fluorescence tomography  

NASA Astrophysics Data System (ADS)

The work presented herein describes the system design and performance evaluation of a miniaturized near-infrared fluorescence (NIRF) frequency-domain photon migration (FDPM) system with non-contact excitation and homodyne detection capability for small animal fluorescence tomography. The FDPM system was developed specifically for incorporation into a Siemens micro positron emission tomography/computed tomography (microPET/CT) commercial scanner for hybrid small animal imaging, but could be adapted to other systems. Operating at 100 MHz, the system noise was minimized and the associated amplitude and phase errors were characterized to be ±0.7% and ±0.3°, respectively. To demonstrate the tomographic ability, a commercial mouse-shaped phantom with 50 µM IRDye800CW and 68Ga containing inclusion was used to associate PET and NIRF tomography. Three-dimensional mesh generation and anatomical referencing was accomplished through CT. A third-order simplified spherical harmonics approximation (SP3) algorithm, for efficient prediction of light propagation in small animals, was tailored to incorporate the FDPM approach. Finally, the PET-NIRF target co-localization accuracy was analyzed in vivo with a dual-labeled imaging agent targeting orthotopic growth of human prostate cancer. The obtained results validate the integration of time-dependent fluorescence tomography system within a commercial microPET/CT scanner for multimodality small animal imaging.

Darne, Chinmay D.; Lu, Yujie; Tan, I.-Chih; Zhu, Banghe; Rasmussen, John C.; Smith, Anne M.; Yan, Shikui; Sevick-Muraca, Eva M.

2012-12-01

341

Nanoscale integration of SiC/SiO2 core-shell nanocables in diamond through a simultaneous hybrid structure fabrication  

NASA Astrophysics Data System (ADS)

The nanoscale integration of SiC nanocables in a diamond thin film is achieved through a novel synthetic pathway, which combines Fe catalyst and detonation nanodiamond seeding technique in a microwave plasma chemical vapor deposition process. The obtained hybrid structures show controllable SiC nanocable fraction depending on the relative fraction of iron catalyst and diamond seeds. The SiC nanocable has a conical structure with 10 nm diameter SiC core, surrounded by SiO2 shell. The diamond crystals show high quality/crystallinity even for hybrid structures featuring an increasing SiC nanocable fraction. In the end, the growth behavior of the hybrid structure is discussed.

Zhuang, Hao; Zhang, Lei; Staedler, Thorsten; Jiang, Xin

2012-05-01

342

Integrated, Feed-Forward Hybrid Electric Vehicle Simulation in SIMULINK and its Use for Power Management Studies  

Microsoft Academic Search

A hybrid electric vehicle simulation tool (HE-VESIM) has been developed at the Automotive Research Center of the University of Michigan to study the fuel economy potential of hybrid military\\/civilian trucks. In this paper, the fundamental architecture of the feed-forward parallel hybrid-electric vehicle system is described, together with dynamic equations and basic features of sub-system modules. Two vehicle-level power management control

Chan-Chiao Lin; Zoran Filipi; Yongsheng Wang; Loucas Louca; Huei Peng; Dennis Assanis; Jeffrey Stein

2001-01-01

343

A Multi-Level Grid Interactive Bi-directional AC/DC-DC/AC Converter and a Hybrid Battery/Ultra-capacitor Energy Storage System with Integrated Magnetics for Plug-in Hybrid Electric Vehicles  

SciTech Connect

This study presents a bi-directional multi-level power electronic interface for the grid interactions of plug-in hybrid electric vehicles (PHEVs) as well as a novel bi-directional power electronic converter for the combined operation of battery/ultracapacitor hybrid energy storage systems (ESS). The grid interface converter enables beneficial vehicle-to-grid (V2G) interactions in a high power quality and grid friendly manner; i.e, the grid interface converter ensures that all power delivered to/from grid has unity power factor and almost zero current harmonics. The power electronic converter that provides the combined operation of battery/ultra-capacitor system reduces the size and cost of the conventional ESS hybridization topologies while reducing the stress on the battery, prolonging the battery lifetime, and increasing the overall vehicle performance and efficiency. The combination of hybrid ESS is provided through an integrated magnetic structure that reduces the size and cost of the inductors of the ESS converters. Simulation and experimental results are included as prove of the concept presenting the different operation modes of the proposed converters.

Onar, Omer C [ORNL

2011-01-01

344

Evidence that the proliferation stage of micropropagation procedure is determinant in the expression of Banana streak virus integrated into the genome of the FHIA 21 hybrid ( Musa AAAB)  

Microsoft Academic Search

Summary.  ?Banana streak virus (BSV) is causing increasing concern in almost every producing area of banana and plantain (Musa spp.) worldwide. This situation appeared partially linked to some breeding lines and micropropagated hybrids. A complete\\u000a BSV sequence integrated into the genome of a triploid plantain has been recently characterised and it has been hypothesised\\u000a that it could give rise to infectious

S. Dallot; P. Acuña; C. Rivera; P. Ramírez; F. C?te; B. E. L. Lockhart; M. L. Caruana

2001-01-01

345

Comparative analysis of stationary-phase Monte Carlo methods  

SciTech Connect

The authors consider the stationary-phase Monte Carlo method and a variety of related approaches. The stationary-phase Monte Carlo method is aimed at the generic problem of performing high-dimensional integrations of rapidly oscillatory integrands. Real time numerical path integration is one important class of applications where such problems arise. They examine the relationship between the stationary-phase Monte Carlo approach and the recent work of Makri and Miller and Filinov.

Doll, J.D.; Freeman, D.L.

1988-06-02

346

Zinc oxide-montmorillonite hybrid influences diarrhea, intestinal mucosal integrity, and digestive enzyme activity in weaned pigs.  

PubMed

One hundred-eighty piglets (Duroc × Landrace × Yorkshire), with an average initial weight of 7.4 kg weaned at 27 ± 1 days of age, were used to evaluate the effects of dietary zinc oxide-montmorillonite hybrid (ZnO-MMT) on growth performance, diarrhea, intestinal mucosal integrity, and digestive enzyme activity. All pigs were allotted to five treatments and fed with the basal diets supplemented with 0, 250, 500, and 750 mg/kg of Zn as ZnO-MMT or 2,000 mg/kg of Zn as ZnO. The results showed that supplementation with 500 or 750 mg/kg of Zn from ZnO-MMT and 2,000 mg/kg of Zn from ZnO improved average daily gain, enhanced average daily feed intake, decreased fecal scores at 4, 8, and 14 days postweaning, reduced intestinal permeability which was evident from the reduced lactulose recovery and urinary lactulose/mannitol ratio, and improved the activities of protease, amylase, lipase, trypsin, and chymotrypsin both in pancreas and small intestinal contents of pigs as compared with the control. Supplemental 250 mg/kg of Zn from ZnO-MMT also decreased fecal scores at 8 and 14 days postweaning, decreased urinary lactulose/mannitol ratio, and improved chymotrypsin activity in pancreas and small intestinal contents as well as protease activity in small intestinal contents compared with control. Moreover, the above indexes of weanling pigs fed with 500 or 750 mg/kg of Zn as ZnO-MMT did not differ from those fed with 2,000 mg/kg of Zn as ZnO. The results demonstrated that supplementation with 500 or 750 mg/kg of Zn from ZnO-MMT was as efficacious as 2,000 mg/kg of Zn from ZnO in improving growth performance, alleviating postweaning diarrhea, and enhancing intestinal mucosal integrity and the digestive enzyme activities in pancreas and small intestinal contents of pigs. The results that feeding lower concentrations of ZnO-MMT to weanling pigs maintained performance will be beneficial for the environment and for sustaining swine production. PMID:22539019

Hu, Caihong; Song, Juan; You, Zhaotong; Luan, Zhaoshuang; Li, Weifen

2012-04-28

347

The MC21 Monte Carlo Transport Code  

SciTech Connect

MC21 is a new Monte Carlo neutron and photon transport code currently under joint development at the Knolls Atomic Power Laboratory and the Bettis Atomic Power Laboratory. MC21 is the Monte Carlo transport kernel of the broader Common Monte Carlo Design Tool (CMCDT), which is also currently under development. The vision for CMCDT is to provide an automated, computer-aided modeling and post-processing environment integrated with a Monte Carlo solver that is optimized for reactor analysis. CMCDT represents a strategy to push the Monte Carlo method beyond its traditional role as a benchmarking tool or ''tool of last resort'' and into a dominant design role. This paper describes various aspects of the code, including the neutron physics and nuclear data treatments, the geometry representation, and the tally and depletion capabilities.

Sutton TM, Donovan TJ, Trumbull TH, Dobreff PS, Caro E, Griesheimer DP, Tyburski LJ, Carpenter DC, Joo H

2007-01-09

348

Asymptotics of fixed point distributions for inexact Monte Carlo algorithms  

SciTech Connect

We introduce a simple general method for finding the equilibrium distribution for a class of widely used inexact Markov chain Monte Carlo algorithms. The explicit error due to the noncommutativity of the updating operators when numerically integrating Hamilton's equations can be derived using the Baker-Campbell-Hausdorff formula. This error is manifest in the conservation of a shadow Hamiltonian that lies close to the desired Hamiltonian. The fixed point distribution of inexact hybrid algorithms may then be derived taking into account that the fixed point of the momentum heat bath and that of the molecular dynamics do not coincide exactly. We perform this derivation for various inexact algorithms used for lattice QCD calculations.

Clark, M. A.; Kennedy, A. D. [Center for Computational Sciences, Boston University, 3 Cummington Street, Boston, Massachusetts 02215 (United States); School of Physics, University of Edinburgh, Mayfield Road, Edinburgh, EH9 3JZ (United Kingdom)

2007-10-01

349

Desiccant-Based Combined Systems: Integrated Active Desiccant Rooftop Hybrid System Development and Testing Final Report- Phase 4  

SciTech Connect

This report summarizes the results of a research and development (R&D) program to design and optimize an active desiccant-vapor compression hybrid rooftop system. The primary objective was to combine the strengths of both technologies to produce a compact, high-performing, energy-efficient system that could accommodate any percentage of outdoor air and deliver essentially any required combination of temperature and humidity, or sensible heat ratio (SHR). In doing so, such a product would address the significant challenges imposed on the performance capabilities of conventional packaged rooftop equipment by standards 62 and 90.1 of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. The body of work completed as part of this program built upon previous R&D efforts supported by the U.S. Department of Energy and summarized by the Phase 3b report ''Active Desiccant Dehumidification Module Integration with Rooftop Packaged HVAC Units'' (Fischer and Sand 2002), in addition to Fischer, Hallstrom, and Sand 2000; Fischer 2000; and Fischer and Sand 2004. All initial design objectives established for this development program were successfully achieved. The performance flexibility desired was accomplished by a down-sized active desiccant wheel that processes only a portion of the supply airflow, which is pre-conditioned by a novel vapor compression cycle. Variable-speed compressors are used to deliver the capacity control required by a system handling a high percentage of outdoor air. An integrated direct digital control system allows for control capabilities not generally offered by conventional packaged rooftop systems. A 3000-cfm prototype system was constructed and tested in the SEMCO engineering test laboratory in Columbia, MO, and was found to operate in an energy-efficient fashion relative to more conventional systems. Most important, the system offered the capability to independently control the supply air temperature and humidity content to provide individual sensible and latent loads required by an occupied space without over-cooling and reheating air. The product was developed using a housing construction similar to that of a conventional packaged rooftop unit. The resulting integrated active desiccant rooftop (IADR) is similar in size to a currently available conventional rooftop unit sized to provide an equivalent total cooling capacity. Unlike a conventional rooftop unit, the IADR can be operated as a dedicated outdoor air system processing 100% outdoor air, as well as a total conditioning system capable of handling any ratio of return air to outdoor air. As part of this R&D program, a detailed investigation compared the first cost and operating cost of the IADR with costs for a conventional packaged approach for an office building located in Jefferson City, MO. The results of this comparison suggest that the IADR approach, once commercialized, could be cost-competitive with existing technology--exhibiting a one-year to two-year payback period--while simultaneously offering improved humidity control, indoor air quality, and energy efficiency.

Fischer, J

2005-05-06

350

Semiclassical approximation solved by Monte Carlo integration as an efficient impurity solver for dynamical mean field theory and its cluster extensions  

NASA Astrophysics Data System (ADS)

We propose that a combination of the semiclassical approximation with Monte Carlo simulations can be an efficient and reliable impurity solver for dynamical mean field theory equations and their cluster extensions with large cluster sizes. In order to show the reliability of the method, we consider two test cases: (i) the single-band Hubbard model within the dynamical cluster approximation with four- and eight-site clusters and (ii) the anisotropic two-orbital Hubbard model with orbitals of different bandwidth within the single-site dynamical mean field theory. We compare the critical interaction Uc/t with those obtained from solving the dynamical mean field equations with the continuous-time and Hirsch-Fye quantum Monte Carlo approaches. In both test cases we observe reasonable values of the metal-insulator critical interaction strength Uc/t and the nature of Mott physics in the self-energy behavior. While some details of the spectral functions cannot be captured by the semiclassical approximation due to the freezing of dynamical fluctuations, the main features are reproduced by the approach.

Lee, Hunpyo; Zhang, Yu-Zhong; Lee, Hoonkyung; Kwon, Yongkyung; Jeschke, Harald O.; Valentí, Roser

2013-10-01

351

A comparative review on small scale integration of hybrid fuel cell and PV generating system to utility network  

Microsoft Academic Search

A comparative review is presented for integrated PEM Fuel Cell and Photovoltaic generating system to single phase utility grid. Different techniques of common coupling for integration have been investigated for this system. For both common AC bus and Common DC bus integration schemes, two different current control techniques have been investigated. The simulation result shows that common DC bus integration

D. Sabaripandiyan; S. Arul Daniel

2010-01-01

352

Prognostic value of cardiac hybrid imaging integrating single-photon emission computed tomography with coronary computed tomography angiography.  

PubMed

Aims Although cardiac hybrid imaging, fusing single-photon emission computed tomography (SPECT) myocardial perfusion imaging with coronary computed tomography angiography (CCTA), provides important complementary diagnostic information for coronary artery disease (CAD) assessment, no prognostic data exist on the predictive value of cardiac hybrid imaging. Hence, the aim of this study was to assess the prognostic value of hybrid SPECT/CCTA images. Methods and results Of 335 consecutive patients undergoing a 1-day stress/rest (99m)Tc-tetrofosmin SPECT and a CCTA, acquired on stand-alone scanners and fused to obtain cardiac hybrid images, follow-up was obtained in 324 patients (97%). Survival free of all-cause death or non-fatal myocardial infarction (MI) and free of major adverse cardiac events (MACE: death, MI, unstable angina requiring hospitalization, coronary revascularizations) was determined using the Kaplan-Meier method for the following groups: (i) stenosis by CCTA and matching reversible SPECT defect; (ii) unmatched CCTA and SPECT finding; and (iii) normal finding by CCTA and SPECT. Cox's proportional hazard regression was used to identify independent predictors for cardiac events. At a median follow-up of 2.8 years (25th-75th percentile: 1.9-3.6), 69 MACE occurred in 47 patients, including 20 death/MI. A corresponding matched hybrid image finding was associated with a significantly higher death/MI incidence (P < 0.005) and proved to be an independent predictor for MACE. The annual death/MI rate was 6.0, 2.8, and 1.3% for patients with matched, unmatched, and normal findings. Conclusion Cardiac hybrid imaging allows risk stratification in patients with known or suspected CAD. A matched defect on hybrid image is a strong predictor of MACE. PMID:21320906

Pazhenkottil, Aju P; Nkoulou, René N; Ghadri, Jelena-Rima; Herzog, Bernhard A; Buechel, Ronny R; Küest, Silke M; Wolfrum, Mathias; Fiechter, Michael; Husmann, Lars; Gaemperli, Oliver; Kaufmann, Philipp A

2011-02-14

353

A hybrid architecture for integrating Mobile ad hoc network and the internet using Fixed and Mobile Gateways  

Microsoft Academic Search

The integration of wired and wireless networks is gaining popularity due to its usefulness and practical use. Internet connectivity would benefit users from mobility offered by mobile ad hoc networks and connectivity provided by the Internet. This integration however faces problem due to architectural differences in terms of infrastructure, topology, and mobility mechanisms. A number of integration strategies have been

K. U. R. Khan; M. A. Ahmed; A. Venugopal Reddy; Rafi U Zaman

2008-01-01

354

A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO 3 photoelastic waveguide  

Microsoft Academic Search

An investigation of the properties of a LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical\\u000a accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration.\\u000a The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its

Dong-lin Tang; Xiao-dong Zhang; Guang-hui Zhao; Zhi-yong Dai; Xin Lai; Feng Guo

2009-01-01

355

Iterative acceleration methods for Monte Carlo and deterministic criticality calculations  

SciTech Connect

If you have ever given up on a nuclear criticality calculation and terminated it because it took so long to converge, you might find this thesis of interest. The author develops three methods for improving the fission source convergence in nuclear criticality calculations for physical systems with high dominance ratios for which convergence is slow. The Fission Matrix Acceleration Method and the Fission Diffusion Synthetic Acceleration (FDSA) Method are acceleration methods that speed fission source convergence for both Monte Carlo and deterministic methods. The third method is a hybrid Monte Carlo method that also converges for difficult problems where the unaccelerated Monte Carlo method fails. The author tested the feasibility of all three methods in a test bed consisting of idealized problems. He has successfully accelerated fission source convergence in both deterministic and Monte Carlo criticality calculations. By filtering statistical noise, he has incorporated deterministic attributes into the Monte Carlo calculations in order to speed their source convergence. He has used both the fission matrix and a diffusion approximation to perform unbiased accelerations. The Fission Matrix Acceleration method has been implemented in the production code MCNP and successfully applied to a real problem. When the unaccelerated calculations are unable to converge to the correct solution, they cannot be accelerated in an unbiased fashion. A Hybrid Monte Carlo method weds Monte Carlo and a modified diffusion calculation to overcome these deficiencies. The Hybrid method additionally possesses reduced statistical errors.

Urbatsch, T.J.

1995-11-01

356

A Monte Carlo simulation of ion transport at finite temperatures  

NASA Astrophysics Data System (ADS)

We have developed a Monte Carlo simulation for ion transport in hot background gases, which is an alternative way of solving the corresponding Boltzmann equation that determines the distribution function of ions. We consider the limit of low ion densities when the distribution function of the background gas remains unchanged due to collision with ions. Special attention has been paid to properly treating the thermal motion of the host gas particles and their influence on ions, which is very important at low electric fields, when the mean ion energy is comparable to the thermal energy of the host gas. We found the conditional probability distribution of gas velocities that correspond to an ion of specific velocity which collides with a gas particle. Also, we have derived exact analytical formulae for piecewise calculation of the collision frequency integrals. We address the cases when the background gas is monocomponent and when it is a mixture of different gases. The techniques described here are required for Monte Carlo simulations of ion transport and for hybrid models of non-equilibrium plasmas. The range of energies where it is necessary to apply the technique has been defined. The results we obtained are in excellent agreement with the existing ones obtained by complementary methods. Having verified our algorithm, we were able to produce calculations for Ar+ ions in Ar and propose them as a new benchmark for thermal effects. The developed method is widely applicable for solving the Boltzmann equation that appears in many different contexts in physics.

Ristivojevic, Zoran; Petrovi?, Zoran Lj

2012-06-01

357

Hybrid Photovoltaic Thermal (PV\\/T) Air and Water Based Solar Collectors Suitable for Building Integrated Applica tions  

Microsoft Academic Search

Problem statement: Experiments have been conducted to investigate the effect of mass flow rates on the electrical, thermal and combined of photovoltaic thermal efficiencies of the hybrid collectors. Approach: Two photovoltaic thermal solar collectors were des igned and fabricated. The first collector, known as spiral flow absorber coll ector, designed to generate hot water and electrici ty. The second collector,

Adnan Ibrahim; Goh Li Jin; Roonak Daghigh; Mohd Huzmin Mohamed Salleh; Mohd Yusof Othman; Mohd Hafidz Ruslan; Sohif Mat; Kamaruzzaman Sopian

2009-01-01

358

An Integrated Hybrid Power Supply for Off-Grid Applications Fed by Wind\\/Photovoltaic\\/Fuel Cell Energy Systems  

Microsoft Academic Search

This paper introduces a method to unit sizing hybrid wind\\/Photovoltaic\\/Fuel Cell generation system for a typical domestic load that is not located near the electric grid. In this configuration the combination of a battery, an electrolyser, and a hydrogen storage tank are used as the energy storage system. The aim of this design is finding the configuration, among a set

Hossein Kord; Ahmad Rohani

359

A Novel Integrated Magnetic Structure Based DC/DC Converter for Hybrid Battery/Ultracapacitor Energy Storage Systems  

SciTech Connect

This manuscript focuses on a novel actively controlled hybrid magnetic battery/ultracapacitor based energy storage system (ESS) for vehicular propulsion systems. A stand-alone battery system might not be sufficient to satisfy peak power demand and transient load variations in hybrid and plug-in hybrid electric vehicles (HEV, PHEV). Active battery/ultracapacitor hybrid ESS provides a better solution in terms of efficient power management and control flexibility. Moreover, the voltage of the battery pack can be selected to be different than that of the ultracapacitor, which will result in flexibility of design as well as cost and size reduction of the battery pack. In addition, the ultracapacitor bank can supply or recapture a large burst of power and it can be used with high C-rates. Hence, the battery is not subjected to supply peak and sharp power variations, and the stress on the battery will be reduced and the battery lifetime would be increased. Utilizing ultracapacitor results in effective capturing of the braking energy, especially in sudden braking conditions.

Onar, Omer C [ORNL

2012-01-01

360

Hybrid Support Vector Regression and Autoregressive Integrated Moving Average Models Improved by Particle Swarm Optimization for Property Crime Rates Forecasting with Economic Indicators  

PubMed Central

Crimes forecasting is an important area in the field of criminology. Linear models, such as regression and econometric models, are commonly applied in crime forecasting. However, in real crimes data, it is common that the data consists of both linear and nonlinear components. A single model may not be sufficient to identify all the characteristics of the data. The purpose of this study is to introduce a hybrid model that combines support vector regression (SVR) and autoregressive integrated moving average (ARIMA) to be applied in crime rates forecasting. SVR is very robust with small training data and high-dimensional problem. Meanwhile, ARIMA has the ability to model several types of time series. However, the accuracy of the SVR model depends on values of its parameters, while ARIMA is not robust to be applied to small data sets. Therefore, to overcome this problem, particle swarm optimization is used to estimate the parameters of the SVR and ARIMA models. The proposed hybrid model is used to forecast the property crime rates of the United State based on economic indicators. The experimental results show that the proposed hybrid model is able to produce more accurate forecasting results as compared to the individual models.

Alwee, Razana; Hj Shamsuddin, Siti Mariyam; Sallehuddin, Roselina

2013-01-01

361

Monte Carlo fundamentals  

SciTech Connect

This report is composed of the lecture notes from the first half of a 32-hour graduate-level course on Monte Carlo methods offered at KAPL. These notes, prepared by two of the principle developers of KAPL`s RACER Monte Carlo code, cover the fundamental theory, concepts, and practices for Monte Carlo analysis. In particular, a thorough grounding in the basic fundamentals of Monte Carlo methods is presented, including random number generation, random sampling, the Monte Carlo approach to solving transport problems, computational geometry, collision physics, tallies, and eigenvalue calculations. Furthermore, modern computational algorithms for vector and parallel approaches to Monte Carlo calculations are covered in detail, including fundamental parallel and vector concepts, the event-based algorithm, master/slave schemes, parallel scaling laws, and portability issues.

Brown, F.B.; Sutton, T.M.

1996-02-01

362

ITS version 5.0 :the integrated TIGER series of coupled electron/Photon monte carlo transport codes with CAD geometry.  

SciTech Connect

ITS is a powerful and user-friendly software package permitting state-of-the-art Monte Carlo solution of linear time-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 5.0, the latest version of ITS, contains (1) improvements to the ITS 3.0 continuous-energy codes, (2) multigroup codes with adjoint transport capabilities, (3) parallel implementations of all ITS codes, (4) a general purpose geometry engine for linking with CAD or other geometry formats, and (5) the Cholla facet geometry library. Moreover, the general user friendliness of the software has been enhanced through increased internal error checking and improved code portability.

Franke, Brian Claude; Kensek, Ronald Patrick; Laub, Thomas William

2005-09-01

363

Sewage treatment using an integrated system consisting of anaerobic hybrid reactor (AHR) and downflow hanging sponge (DHS)  

Microsoft Academic Search

This paper presents an evaluation of a combined wastewater treatment train consisting of an anaerobic hybrid reactor (AHR) followed by a downflow hanging sponge (DHS) system. The combined system was operated at a total constant hydraulic retention time (HRT) of 8 h (AHR: 6.0 h and DHS: 2.0 h) and an average organic loading rate of 1.9 kg COD\\/m.d for

M. Mahmoud; A. Tawfik; F. Samhan; F. El-Gohary

2009-01-01

364

Bayesian adaptive Markov chain Monte Carlo estimation of genetic parameters  

PubMed Central

Accurate and fast estimation of genetic parameters that underlie quantitative traits using mixed linear models with additive and dominance effects is of great importance in both natural and breeding populations. Here, we propose a new fast adaptive Markov chain Monte Carlo (MCMC) sampling algorithm for the estimation of genetic parameters in the linear mixed model with several random effects. In the learning phase of our algorithm, we use the hybrid Gibbs sampler to learn the covariance structure of the variance components. In the second phase of the algorithm, we use this covariance structure to formulate an effective proposal distribution for a Metropolis-Hastings algorithm, which uses a likelihood function in which the random effects have been integrated out. Compared with the hybrid Gibbs sampler, the new algorithm had better mixing properties and was approximately twice as fast to run. Our new algorithm was able to detect different modes in the posterior distribution. In addition, the posterior mode estimates from the adaptive MCMC method were close to the REML (residual maximum likelihood) estimates. Moreover, our exponential prior for inverse variance components was vague and enabled the estimated mode of the posterior variance to be practically zero, which was in agreement with the support from the likelihood (in the case of no dominance). The method performance is illustrated using simulated data sets with replicates and field data in barley.

Mathew, B; Bauer, A M; Koistinen, P; Reetz, T C; Leon, J; Sillanpaa, M J

2012-01-01

365

MORSE Monte Carlo Code.  

National Technical Information Service (NTIS)

The MORSE code is a large general-use multigroup Monte Carlo code system. Although no claims can be made regarding its superiority in either theoretical details or Monte Carlo techniques, MORSE has been, since its inception at ORNL in the late 1960s, the ...

S. N. Cramer

1984-01-01

366

AZEOTROPE PREDICTION BY MONTE CARLO MOLECULAR SIMULATION  

Microsoft Academic Search

This article presents a methodology for checking the existence of the azeotrope and computing its composition, density, and pressure at a given temperature by integrating chemical engineering insights with molecular simulation principles. Liquid-vapor equilibrium points are computed by molecular simulations using the Gibbs ensemble Monte Carlo (GEMC) method at constant volume. The appearance of the azeotropic point is marked by

M. K. Hadj-Kali; V. Gerbaud; X. Joulia

2012-01-01

367

Angular biasing in implicit Monte-Carlo  

Microsoft Academic Search

Calculations of indirect drive Inertial Confinement Fusion target experiments require an integrated approach in which laser irradiation and radiation transport in the hohlraum are solved simultaneously with the symmetry, implosion and burn of the fuel capsule. The Implicit Monte Carlo method has proved to be a valuable tool for the two dimensional radiation transport within the hohlraum, but the impact

1994-01-01

368

Optical properties of tumor tissues grown on the chorioallantoic membrane of chicken eggs measured with a double integrating sphere and inverse Monte Carlo method in the wavelength range of 350-1000 nm  

NASA Astrophysics Data System (ADS)

Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is an attractive method because of the shorter decay time of photosensitivity compared with PDT using other drugs. However, the optimum conditions to perform ALA-PDT, e.g., drug dose, wavelength, and irradiation dose have never been clarified. To evaluate the effectiveness of PDT using ALA and its dependence on drug dose, wavelength, and irradiation dose in the treatment of tumors, the usefulness of a tumor model prepared with tumor cells grown on the chorioallantoic membrane of chicken eggs was studied by measuring the optical properties of the tumor model. The optical properties of tumor model were measured with a double integrating sphere optical setup and inverse Monte Carlo technique in the wavelength range from 350 to 1000 nm. The spectra of absorption and reduced scattering coefficients of the tumor model grown in the chicken eggs were compared with those of the other tumor model grown in mice. The measured optical properties of the tumor model using chicken eggs were similar to those of the tumor model using mice. These results indicate that the tumor model using chicken eggs is a suitable system to investigate the effectiveness of ALA-PDT. This in vivo assay system for tumors has advantages for evaluating antitumor effect of ALA-PDT because of its convenience, rapidity, and inexpensiveness.

Honda, Norihiro; Kariyama, Yoichiro; Ishii, Takuya; Abe, Chiaki; Inoue, Katsushi; Ishizuka, Masahiro; Tanaka, Tohru; Hazama, Hisanao; Awazu, Kunio

2013-02-01

369

Monte Carlo simulation of energy-dispersive x-ray fluorescence and applications  

Microsoft Academic Search

Four key components with regards to Monte Carlo Library Least Squares (MCLLS) have been developed by the author. These include: a comprehensive and accurate Monte Carlo simulation code - CEARXRF5 with Differential Operators (DO) and coincidence sampling, Detector Response Function (DRF), an integrated Monte Carlo - Library Least-Squares (MCLLS) Graphical User Interface (GUI) visualization System (MCLLSPro) and a new reproducible

Fusheng Li

2008-01-01

370

Quasi-Monte Carlo Methods in Computer Graphics, Part I: The QMC-Buffer  

Microsoft Academic Search

Monte Carlo integration is often used for antialiasing in rendering processes. Due to low sampling rates only expected error estimates can be stated, and the variance can be high. In this article quasi-Monte Carlo methods are presented, achieving a guaranteed upper error bound and a convergence rate essentially as fast as usual Monte Carlo.

Stefan Heinrich; Alexander Keller

1994-01-01

371

Rapid screening, in vitro study of metal oxide and polymer hybrids as delivery coatings for improved soft-tissue integration of implants.  

PubMed

Metal-organic chemistry allows for molecular mixing and creation of a range of submicron phase-separated structures from normally brittle metal oxides and flexible polymers with improved bioactivity and delivery properties. In this study, we used a high throughput platform to investigate the influence of organic metal oxide doping of polydimethylsiloxane (PDMS) coatings on cellular bioactivity and controlled release of vanadium compared with titanium oxide coatings without additional PDMS. Metal-organic-derived titanium and or vanadium was doped into PDMS and used to form a coating on the bottom of cell culture microplates in the absence of added water, acids, or bases. These hybrid coatings were rapidly screened to establish how titanium and vanadium concentration influences cell proliferation, adhesion, and morphology. We demonstrate that titanium doping of PDMS can be used to improve cell proliferation and adhesion, and that vanadium doping caused a biphasic dose response in proliferation. A 28-day vanadium and titanium elution study indicated that titanium was not released, but the presence of PDMS in coatings increased delivery rates of vanadium compared with titania coatings without polymer. Hybrid coatings of titanium-doped polymers have potential for improving wound healing dynamics, soft-tissue integration of medical implants, and use as controlled delivery vehicles. PMID:19301265

Jarrell, John D; Dolly, Brandon; Morgan, Jeffrey R

2010-03-01

372

Hybridization of the Vector Finite Element Method with the Boundary Integral Method for the Solution of Finite Arrays of Cavity-Backed Slot Antennas  

NASA Astrophysics Data System (ADS)

The vector finite element method (FEM) is hybridized with the boundary integral (BI) method to solve for the radiation characteristics of a cavity-backed slot (CBS) antenna. The hybridization of the two methods is made possible at the aperture of the antenna separating the cavity interior and the half-space exterior region above an infinite conducting ground plane. Having to solve for a finite array of CBS antennas requires an excessive amount of memory, in order to store the system matrix, and considerable CPU time for the solution of the resulting linear system of equations. Increasing the number of array elements results in a non-linear increase in the number of unknowns, thus making the solution of the linear system impossible. In this paper, we adopt array domain decomposition (ADD) and by taking advantage of the repetitive features of the array, we can reduce the memory requirements to a minimum. In addition, we introduce stationary and non-stationary iteration techniques, with or without preconditioning, to solve the system of linear equations in an efficient manner. Singular value decomposition (SVD) is also used in order to further reduce memory requirements and speed-up matrix-vector multiplications that are inherent in either type of iterative techniques. Computational statistics and comparisons between stationary and non-stationary techniques are presented and discussed.

Polycarpou, A. C.

2009-10-01

373

MORSE Monte Carlo code  

SciTech Connect

The MORSE code is a large general-use multigroup Monte Carlo code system. Although no claims can be made regarding its superiority in either theoretical details or Monte Carlo techniques, MORSE has been, since its inception at ORNL in the late 1960s, the most widely used Monte Carlo radiation transport code. The principal reason for this popularity is that MORSE is relatively easy to use, independent of any installation or distribution center, and it can be easily customized to fit almost any specific need. Features of the MORSE code are described.

Cramer, S.N.

1984-01-01

374

Designing integrated guidance law for aerodynamic missiles by hybrid multi-objective evolutionary algorithm and tabu search  

Microsoft Academic Search

In this paper, a strength Pareto evolutionary algorithm (SPEA) based approach is proposed for designing an integrated fuzzy guidance law which consists of three fuzzy controllers. Each of these controllers is activated in a region of the interception. The distribution of the membership functions and the rules are obtained by solving a nonlinear constrained multi-objective optimization problem where final time,

Hanafy M. Omar; M. A. Abido

2010-01-01

375

Entropy-driven polymer collapse: Application of the hybrid MC\\/RISM method to the study of conformational transitions in macromolecules interacting with hard colloidal particles  

Microsoft Academic Search

Self-consistent hybrid MC\\/RISM method is used for calculating properties of a linear polymer surrounded by colloidal particles with purely repulsive, hard-core, interactions between the particles and chain beads. Our approach combines the traditional atomistic Monte-Carlo (MC) simulation of flexible polymer chains with the numerical solution of the site-site Ornstein-Zernike-like (RISM) integral equations. Since the condensed-phase environment of a flexible macromolecule

P. G. Khalatur; L. V. Zherenkova; A. R. Khokhlov

1998-01-01

376

Integration  

NSDL National Science Digital Library

In this video, we become familiar with integrals, both by understanding them as sums of areas under plots of functions, and by understanding them as anti-derivatives. We present the u-substitution rule, which is the analog of the chain rule for differentiating composite functions.

Liao, David

377

General Monte Carlo Reliability Simulation Code Including Common Mode Failures and Harp Fault/Error-Handling.  

National Technical Information Service (NTIS)

A Monte Carlo Fortran computer program was developed that uses two variance reduction techniques for computing system reliability applicable to solving very large highly reliable fault-tolerant systems. The program is consistent with the hybrid automated ...

M. E. Platt E. E. Lewis F. Boehm

1991-01-01

378

Designing an integrated multi-echelon agile supply chain network: a hybrid taguchi-particle swarm optimization approach  

Microsoft Academic Search

The present paper attempts to explore the integration of production, distribution and logistics activities at the strategic\\u000a decision making level where, the objective is to design a multi-echelon supply chain network considering agility as a key\\u000a design criterion. The design network conceived here addresses a class of five echelons of supply chains including suppliers,\\u000a plants, distribution centers, cross-docks and customer

Manish Bachlaus; Mayank Kumar Pandey; Chetan Mahajan; Ravi Shankar; M. K. Tiwari

2008-01-01

379

SH-wave scattering by a semi-elliptical hill using a null-field boundary integral equation method and a hybrid method  

NASA Astrophysics Data System (ADS)

Following the success of seismic analysis of a semi-circular hill, the problem of SH-wave scattering by a semi-elliptical hill is revisited by using the null-field boundary integral equation method (BIEM). To fully use the analytical property in the null-field boundary integral equation approach in conjunction with degenerate kernels for solving the semi-elliptical hill scattering problem, the problem is decomposed to two regions to produce elliptical boundaries by using the technique of taking free body. One is the half-plane problem containing a semi-elliptical boundary. This semi-infinite problem is imbedded in an infinite plane with an artificial elliptical boundary such that degenerate kernel can be fully applied. The other is an interior problem bounded by an elliptical boundary. The degenerate kernel in the elliptic coordinates for two subdomains is used to expand the closed-form fundamental solution. The semi-analytical formulation in companion with matching boundary conditions yields six constraint equations. Instead of finding admissible wave-expansion bases, our null-field BIEM in conjunction with degenerate kernels has the five features over the conventional BIEM/BEM, (1) free of calculating principal values, (2) exponential convergence, (3) elimination of boundary-layer effect, (4) meshless and (5) well-posed system. All numerical results are compared well with those of using the hybrid method which is also described in this paper. It is interesting to find that a focusing phenomenon is also observed in this study.

Chen, Jeng-Tzong; Lee, Jia-Wei; Shyu, Wen-Shinn

2012-01-01

380

Targeted integration and removal of transgenes in hybrid aspen (Populus tremula L. x P. tremuloides Michx.) using site-specific recombination systems.  

PubMed

Two site-specific recombination systems, Cre/lox and FLP/FRT, were tested for marker gene removal and targeted gene transfer in a model tree system. A hybrid aspen clone (Populus tremula x Populus tremuloides) was co-transformed with plasmids containing either the FLP or the Cre recombinase, both under control of a heat-inducible promoter (HSP, Gmhsp17.5-E from soybean) flanked by the two recognition sites (FRT or lox). Molecular investigations of heat-shock treated Cre or FLP transgenic lines indicate excision of inserts between the two recognition sites. Further, a site-specific recombination at the FRT sites leading to targeted integration of a fragment could be demonstrated for the FLP/FRT system. Transgenic aspen carrying two constructs (each with different genes between the FRT sites) revealed (i) excision of both fragments between the FRT sites, and (ii) targeted integration of the fragment from the second construct exactly at the former position of the fragment in the first construct. These results indicate the usefulness of the two site-specific recombination systems in the tree species Populus. Combining both site-specific recombination systems, a strategy is suggested for targeted transgene transfer and removal of antibiotic marker genes. PMID:20398239

Fladung, M; Becker, D

2010-03-01

381

Physical and organizational provision for installation, regulatory requirements and implementation of a simultaneous hybrid PET/MR-imaging system in an integrated research and clinical setting.  

PubMed

The implementation of hybrid imaging systems requires thorough and anticipatory planning at local and regional levels. For installation of combined positron emission and magnetic resonance imaging systems (PET/MRI), a number of physical and constructional provisions concerning shielding of electromagnetic fields (RF- and high-field) as well as handling of radionuclides have to be met, the latter of which includes shielding for the emitted 511 keV gamma rays. Based on our experiences with a SIEMENS Biograph mMR system, a step-by-step approach is required to allow a trouble-free installation. In this article, we present a proposal for a standardized step-by-step plan to accomplish the installation of a combined PET/MRI system. Moreover, guidelines for the smooth operation of combined PET/MRI in an integrated research and clinical setting will be proposed. Overall, the most important preconditions for the successful implementation of PET/MRI in an integrated research and clinical setting is the interdisciplinary target-oriented cooperation between nuclear medicine, radiology, and all referring and collaborating institutions at all levels of interaction (personnel, imaging protocols, reporting, selection of the data transfer and communication methods). PMID:23053713

Sattler, Bernhard; Jochimsen, Thies; Barthel, Henryk; Sommerfeld, Kerstin; Stumpp, Patrick; Hoffmann, Karl-Titus; Gutberlet, Matthias; Villringer, Arno; Kahn, Thomas; Sabri, Osama

2012-10-09

382

Hybrid capture and next-generation sequencing identify viral integration sites from formalin-fixed, paraffin-embedded tissue.  

PubMed

Although next-generation sequencing (NGS) has been the domain of large genome centers, it is quickly becoming more accessible to general pathology laboratories. In addition to finding single-base changes, NGS allows for the detection of larger structural variants, including insertions/deletions, translocations, and viral insertions. We describe the use of targeted NGS on DNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissue, and show that the short read lengths of NGS are ideally suited to fragmented DNA obtained from FFPE tissue. Further, we describe a novel method for performing hybrid-capture target enrichment using PCR-generated capture probes. As a model, we captured the 5.3-kb Merkel cell polyomavirus (MCPyV) genome in FFPE cases of Merkel cell carcinoma using inexpensive, PCR-derived capture probes, and achieved up to 37,000-fold coverage of the MCPyV genome without prior virus-specific PCR amplification. This depth of coverage made it possible to reproducibly detect viral genome deletions and insertion sites anywhere within the human genome. Out of four cases sequenced, we identified the 5' insertion sites in four of four cases and the 3' sites in three of four cases. These findings demonstrate the potential for an inexpensive gene targeting and NGS method that can be easily adapted for use with FFPE tissue to identify large structural rearrangements, opening up the possibility for further discovery from archival tissue. PMID:21497292

Duncavage, Eric J; Magrini, Vincent; Becker, Nils; Armstrong, Jon R; Demeter, Ryan T; Wylie, Todd; Abel, Haley J; Pfeifer, John D

2011-05-01

383

Knowledge extraction algorithm for variances handling of CP using integrated hybrid genetic double multi-group cooperative PSO and DPSO.  

PubMed

Although the clinical pathway (CP) predefines predictable standardized care process for a particular diagnosis or procedure, many variances may still unavoidably occur. Some key index parameters have strong relationship with variances handling measures of CP. In real world, these problems are highly nonlinear in nature so that it's hard to develop a comprehensive mathematic model. In this paper, a rule extraction approach based on combing hybrid genetic double multi-group cooperative particle swarm optimization algorithm (PSO) and discrete PSO algorithm (named HGDMCPSO/DPSO) is developed to discovery the previously unknown and potentially complicated nonlinear relationship between key parameters and variances handling measures of CP. Then these extracted rules can provide abnormal variances handling warning for medical professionals. Three numerical experiments on Iris of UCI data sets, Wisconsin breast cancer data sets and CP variances data sets of osteosarcoma preoperative chemotherapy are used to validate the proposed method. When compared with the previous researches, the proposed rule extraction algorithm can obtain the high prediction accuracy, less computing time, more stability and easily comprehended by users, thus it is an effective knowledge extraction tool for CP variances handling. PMID:20703636

Du, Gang; Jiang, Zhibin; Diao, Xiaodi; Yao, Yang

2010-07-31

384

Analyze of 3D fluid driven crack in saturated porous media under P- and S-waves by hybrid hypersingular integral method  

NASA Astrophysics Data System (ADS)

Strong earthquakes can have catastrophic effects on society, and therefore the precise prediction of large earthquakes is crucial for seismic hazard reduction. The genesis and occurrence of earthquakes and their subsequent effects involve complex physical processes. Studying these processes helps us understand the mechanics of earthquakes and the future physical state of the earth. Earthquake studies focus on the nucleation of rupture, thermo- and hydro-mechanical weakening of fault zones during seismic slip, fracture propagation through branched and offset fault systems, and relations between stress, seismicity, and deformation in or near continental and subduction fault systems. Fluid driven fracture is a fundamental geophysical phenomenon operating in planetary interiors on many scales; it plays a major role in chemical differentiation of the upper mantle and dynamic delayed triggering of earthquakes process. Because our ability to make direct observation of the dynamics and styles of fluid driven fracture is quite limited, our understanding of this phenomenon relies on theoretical models that use fundamental physical principles and available field data to constrain the behavior of fluid driven cracks at depth. However, relatively little work has been done on 3D extended fluid driven crack propagation. This seems to be due mainly to the present limitations on practical methods (such as CPU time and storage requirements) and on theoretical aspects (strongly singular domain integrals). This requires general and accurate theoretical method. This work reports a new and accurate way of theoretical and numerical description of the extended 3D fluid (electromagnetic and flow) driven crack progression in saturated porous media for P- and S-waves under fully coupled electromagnetothermoelastic field. First, based on the viscous fluid flow reciprocal work theorem, the hybrid hypersingular integral equation (HIE) method proposed by the author was defined by combined with the coupled extended wave time-domain HIE, the lattice Boltzmann method and the interface phase field method. The general extended 3D fluid flow velocity wave solutions are obtained by the extended wave time-domains Green's function method. The 3D extended dynamic fluid driven crack modeling under fully coupled electromagnetothermoelastic P- and S-wave and flow field was established. Then, the problem is reduced to solving a set of extended hybrid HIEs coupled with nonlinear boundary domain integral equations, in which the unknown functions are the general extended flow velocity discontinuity waves. The behavior of the general extended singular stress indices around the crack front terminating is analyzed by hybrid time-domain main-part analysis. The general extended singular pore stress waves (SPSWs) and the extended dynamic stress intensity factors (DSIFs) on the fluid driven crack surface are obtained from closed-form solutions. In addition, a numerical method for the problem is proposed, in which the extended velocity discontinuity waves are approximated by the product of time-domain density functions and polynomials. The extended DSIFs and general extended SPSWs are calculated, and the results are presented toward demonstrating the applicability of the proposed method. Key words 3D fluid driven crack propagation mechanism; P- and S-waves; Fully coupled electromagnetothermoelastic field; Hypersingular integral method, Lattice Boltzmann method; Interface phase field method; Extended dynamic stress intensity factor; General extended singular pore stress waves.

Zhu, B. J.; Shi, Y. L.; Sukop, M. C.

2009-04-01

385

Susceptibility of clinical isolates of Pseudomonas aeruginosa in the Northern Kyushu district of Japan to carbapenem antibiotics, determined by an integrated concentration method: evaluation of the method based on Monte Carlo simulation.  

PubMed

In empirical antibacterial therapy, regional surveillance is expected to yield important information for the determination of the class and dosage regimen of antibacterial agents to be used when dealing with infections with organisms such as Pseudomonas aeruginosa, in which strains resistant to antibacterial agents have been increasing. The minimal inhibitory concentrations (MICs) of five carbapenem antibiotics against P. aeruginosa strains isolated in the Northern Kyushu district of Japan between 2005 and 2006 were measured, and 100 strains for which carbapenem MICs were < or =0.5-32 microg/ml were selected. In this study, MIC was measured by two methods, i.e., the common serial twofold dilution method and an integrated concentration method, in which the concentration was changed, in increments of 2 microg/ml, from 2 to 16 microg/ml. The MIC(50)/MIC(90) values for imipenem, meropenem, biapenem, doripenem, and panipenem, respectively, with the former method were 8/16, 4/16, 4/16, 2/8, and 16/16 microg/ml; and the values were 6/10, 4/12, 4/10, 2/6, and 10/16 microg/ml with the latter method. The MIC data obtained with both methods were subjected to pharmacokinetic/pharmacodynamic (PK/PD) analysis with Monte Carlo simulation to calculate the probability of achieving the target of time above MIC (T>MIC) with each carbapenem. The probability of achieving 25% time above the MIC (T>MIC; % of T>MIC for dosing intervals) and 40% T>MIC against P. aeruginosa with any dosage regimen was higher with doripenem than with any other carbapenem tested. When the two sets of MIC data were subjected to PK/PD analysis, the difference between the two methods in the probability of achieving each % T>MIC was small, thus endorsing the validity of the serial twofold dilution method. PMID:18574662

Nagasawa, Zenzo; Kusaba, Koji; Aoki, Yosuke

2008-06-24

386

Enhancements in Continuous-Energy Monte Carlo Capabilities in SCALE  

SciTech Connect

Monte Carlo tools in SCALE are commonly used in criticality safety calculations as well as sensitivity and uncertainty analysis, depletion, and criticality alarm system analyses. Recent improvements in the continuous-energy data generated by the AMPX code system and significant advancements in the continuous-energy treatment in the KENO Monte Carlo eigenvalue codes facilitate the use of SCALE Monte Carlo codes to model geometrically complex systems with enhanced solution fidelity. The addition of continuous-energy treatment to the SCALE Monaco code, which can be used with automatic variance reduction in the hybrid MAVRIC sequence, provides significant enhancements, especially for criticality alarm system modeling. This paper describes some of the advancements in continuous-energy Monte Carlo codes within the SCALE code system.

Bekar, Kursat B [ORNL; Celik, Cihangir [ORNL; Wiarda, Dorothea [ORNL; Peplow, Douglas E. [ORNL; Rearden, Bradley T [ORNL; Dunn, Michael E [ORNL

2013-01-01

387

Analytical insights into the partially integrated transport modeling method for hybrid Reynolds averaged Navier-Stokes equations-large eddy simulations of turbulent flows  

NASA Astrophysics Data System (ADS)

The basis of the partially integrated transport modeling (PITM) method was introduced by Schiestel and Dejoan [``Towards a new partially integrated transport model for coarse grid and unsteady turbulent flow simulations,'' Theor. Comput. Fluid Dyn. 18, 443 (2005)] and Chaouat and Schiestel [``A new partially integrated transport model for subgrid-scale stresses and dissipation rate for turbulent developing flows,'' Phys. Fluids 17, 065106 (2005)]. This method provides a continuous approach for hybrid RANS-LES (Reynolds averaged Navier-Stokes equations-large eddy simulations) simulations with seamless coupling between RANS and LES regions. The main ingredient of the method is the new dissipation-rate equation that can be applied as a subfilter scale turbulence model. Then, it becomes easy to convert almost any usual RANS transport model into a subfilter scale model. In particular, the method can be applied to two equation models and to stress transport models as well. In the derivation of the method, the partial integration technique allows to keep a link between the spectral space and the physical space of the resulting model. The physical turbulent processes involving the production, dissipation, and flux transfer of the turbulent energy are introduced in the equations. The present work, after recalling the main building steps of the PITM method, brings further insight into the physical interpretation of the method, its underlying hypotheses and its internal acting mechanisms. In particular, the finiteness of the coefficients used in the dissipation-rate equation is discussed in detail from a theoretical point of view. Then, we consider the analytical example of self-similar turbulent flow for analyzing the dissipation-rate equation. From an analytical solution obtained by Taylor series expansions taking into account the Kovasznay hypothesis for evaluating the transfer term, we compute the functional coefficients c?2 and csfs?2 used in RANS and LES methodologies, respectively, and we demonstrate that both coefficients take on finite values when the Reynolds number goes to infinity. Finally, after briefly mentioning some flow illustrations to get a real appraisal of the PITM method in its capabilities to simulate unsteady flows on relatively coarse grids with a sufficient accuracy for engineering computations, we study the coefficient csfs?2 through one chosen example.

Chaouat, Bruno; Schiestel, Roland

2012-08-01

388

Monte Python: Monte Carlo Code for CLASS in Python  

NASA Astrophysics Data System (ADS)

Monte Python is a parameter inference code which combines the flexibility of the python language and the robustness of the cosmological code CLASS into a simple and easy to manipulate Monte Carlo Markov Chain code.

Audren, Benjamin; Lesgourgues, Julien; Benabed, Karim; Prunet, Simon

2013-07-01

389

TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket  

NASA Astrophysics Data System (ADS)

This study focused on creating a new tristructural isotropic (TRISO) coated particle fuel performance model and demonstrating the integration of this model into an existing system of neutronics and heat transfer codes, creating a user-friendly option for including fuel performance analysis within system design optimization and system-level trade-off studies. The end product enables both a deeper understanding and better overall system performance of nuclear energy systems limited or greatly impacted by TRISO fuel performance. A thorium-fueled hybrid fusion-fission Laser Inertial Fusion Energy (LIFE) blanket design was used for illustrating the application of this new capability and demonstrated both the importance of integrating fuel performance calculations into mainstream design studies and the impact that this new integrated analysis had on system-level design decisions. A new TRISO fuel performance model named TRIUNE was developed and verified and validated during this work with a novel methodology established for simulating the actual lifetime of a TRISO particle during repeated passes through a pebble bed. In addition, integrated self-consistent calculations were performed for neutronics depletion analysis, heat transfer calculations, and then fuel performance modeling for a full parametric study that encompassed over 80 different design options that went through all three phases of analysis. Lastly, side studies were performed that included a comparison of thorium and depleted uranium (DU) LIFE blankets as well as some uncertainty quantification work to help guide future experimental work by assessing what material properties in TRISO fuel performance modeling are most in need of improvement. A recommended thorium-fueled hybrid LIFE engine design was identified with an initial fuel load of 20MT of thorium, 15% TRISO packing within the graphite fuel pebbles, and a 20cm neutron multiplier layer with beryllium pebbles in flibe molten salt coolant. It operated at a system power level of 2000 MWth, took about 3.5 years to reach full plateau power, and was capable of an End of Plateau burnup of 38.7 %FIMA if considering just the neutronic constraints in the system design; however, fuel performance constraints led to a maximum credible burnup of 12.1 %FIMA due to a combination of internal gas pressure and irradiation effects on the TRISO materials (especially PyC) leading to SiC pressure vessel failures. The optimal neutron spectrum for the thorium-fueled blanket options evaluated seemed to favor a hard spectrum (low but non-zero neutron multiplier thicknesses and high TRISO packing fractions) in terms of neutronic performance but the fuel performance constraints demonstrated that a significantly softer spectrum would be needed to decrease the rate of accumulation of fast neutron fluence in order to improve the maximum credible burnup the system could achieve.

Padmini Mukkamala, V. S.

390

Measurement and hybrid model analysis of integral excitation functions for proton-induced reactions on vanadium, manganese and cobalt up to 200 MeV  

NASA Astrophysics Data System (ADS)

Integral excitation functions for p-induced reactions on V, Mn and Co were measured for p-energies between 45 and 200 MeV. 30 excitation functions for the production of radionuclides with 43 <= A <= 60 were determined. For most of the reactions, ranging from (p, n) to (p, 7p9n), scarcely no experimental data existed before now in this energy region. Together with earlier measurements the new data provide a consistent set of excitation functions of p-induced reactions from 0 to 200 MeV for these elements. A detailed hybrid model analysis was performed using the recent code ALICE LIVERMORE 82, which in contrast to earlier formulations of the model takes into account experimental mass data, multiple preequilibrium nucleon emission and non-integer initial excitation numbers. In general, the a priori calculations satisfactorily reproduce the experimental excitation functions. Some discrepancies have to be attributed to the neglect of direct processes and of preequilibrium emission of ?-particles. The reasons for a complete failure of the calculations in some exceptional cases are still not clear.

Michel, R.; Peiffer, F.; Stück, R.

1985-08-01

391

Improved geometry representations for Monte Carlo radiation transport.  

SciTech Connect

ITS (Integrated Tiger Series) permits a state-of-the-art Monte Carlo solution of linear time-integrated coupled electron/photon radiation transport problems with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. ITS allows designers to predict product performance in radiation environments.

Martin, Matthew Ryan (Cornell University)

2004-08-01

392

Theory of the Monte Carlo method for semiconductor device simulation  

Microsoft Academic Search

A brief review of the semiclassical Monte Carlo (MC) method for semiconductor device simulation is given, covering the standard MC algorithms, variance reduction techniques, the self-consistent solution, and the physical semiconductor model. A link between physically based MC methods and the numerical method of MC integration is established. The integral representations the transient and the steady-state Boltzmann equations are presented

Hans Kosina; Michail Nedjalkov; Siegfried Selberherr

2000-01-01

393

Integral analysis method - IAM  

Microsoft Academic Search

This paper presents the theoretical foundations of the new integral analysis method (IAM), and its application to a facility location problem. This methodology integrates the cardinal and ordinal criteria of combinatorial stochastic optimization problems in four stages: definition of the problem, cardinal analysis, ordinal analysis and integration analysis. The method uses the concepts of stochastic multicriteria acceptability analysis (SMAA), Monte

Rafael Guillermo García Cáceres; Julián Arturo Aráoz Durand; Fernando Palacios Gómez

2009-01-01

394

Monte Carlo Event Generators  

NASA Astrophysics Data System (ADS)

Every neutrino experiment requires a Monte Carlo event generator for various purposes. Historically, each series of experiments developed their own code which tuned to their needs. Modern experiments would benefit from a universal code (e.g. PYTHIA) which would allow more direct comparison between experiments. GENIE attempts to be that code. This paper compares most commonly used codes and provides some details of GENIE.

Dytman, Steven

2011-10-01

395

Microcanonical Monte Carlo  

SciTech Connect

A recently developed algorithm for simulating statistical systems is discussed. The procedure interpolates between molecular dynamics methods and canonical Monte Carlo. The primary advantages are extremely fast simulations of discrete systems such as the Ising model and a relative insensitivity to random number quality. A variation of the algorithm gives rise to a deterministic dynamics for Ising spins. This model may be useful for high speed simulation of non-equilibrium phenomena. 8 refs., 2 figs.

Creutz, M.

1986-01-01

396

Monte Carlo Event Generators  

SciTech Connect

Every neutrino experiment requires a Monte Carlo event generator for various purposes. Historically, each series of experiments developed their own code which tuned to their needs. Modern experiments would benefit from a universal code (e.g. PYTHIA) which would allow more direct comparison between experiments. GENIE attempts to be that code. This paper compares most commonly used codes and provides some details of GENIE.

Dytman, Steven [Department.of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

2011-10-06

397

An approximate technique for the integrations of the equations of motion in a free electron laser (FEL). One dimensional Monte Carlo analysis of a free electron laser (FEL) in a storage ring. Final report May--June 1977  

Microsoft Academic Search

The final report for this contract consists of two articles submitted for publication in the open literature. In the first article the authors describe an approximation they have used to compute gain, saturation, and electron statistics for a free electron laser. In the second article they report the results of a Monte Carlo method one-dimensional analysis of the equilibrium energy

J. M. J. Madey; D. A. G. Deacon; L. R. Elias; T. I. Smith

1978-01-01

398

An approximate technique for the integrations of the equations of motion in a Free Electron Laser (FEL). One dimensional Monte Carlo analysis of a Free Electron Laser (FEL). In a storage ring  

Microsoft Academic Search

The final report for this contract consists of two articles submitted for publication in the open literature. In the first article the authors describe an approximation they have used to compute gain, saturation, and electron statistics for a free electron laser. In the second article they report the results of a Monte Carlo method one-dimensional analysis of the equilibrium energy

J. M. J. Madey; D. A. G. Deacon; L. R. Elias; T. I. Smith

1978-01-01

399

Monte Carlo eikonal scattering  

NASA Astrophysics Data System (ADS)

Background: The eikonal approximation is commonly used to calculate heavy-ion elastic scattering. However, the full evaluation has only been done (without the use of Monte Carlo techniques or additional approximations) for ?-? scattering.Purpose: Develop, improve, and test the Monte Carlo eikonal method for elastic scattering over a wide range of nuclei, energies, and angles.Method: Monte Carlo evaluation is used to calculate heavy-ion elastic scattering for heavy nuclei including the center-of-mass correction introduced in this paper and the Coulomb interaction in terms of a partial-wave expansion. A technique for the efficient expansion of the Glauber amplitude in partial waves is developed.Results: Angular distributions are presented for a number of nuclear pairs over a wide energy range using nucleon-nucleon scattering parameters taken from phase-shift analyses and densities from independent sources. We present the first calculations of the Glauber amplitude, without further approximation, and with realistic densities for nuclei heavier than helium. These densities respect the center-of-mass constraints. The Coulomb interaction is included in these calculations.Conclusion: The center-of-mass and Coulomb corrections are essential. Angular distributions can be predicted only up to certain critical angles which vary with the nuclear pairs and the energy, but we point out that all critical angles correspond to a momentum transfer near 1 fm-1.

Gibbs, W. R.; Dedonder, J. P.

2012-08-01

400

Monte Carlo alpha calculation  

SciTech Connect

A Monte Carlo algorithm to efficiently calculate static alpha eigenvalues, N = ne/sup ..cap alpha..t/, for supercritical systems has been developed and tested. A direct Monte Carlo approach to calculating a static alpha is to simply follow the buildup in time of neutrons in a supercritical system and evaluate the logarithmic derivative of the neutron population with respect to time. This procedure is expensive, and the solution is very noisy and almost useless for a system near critical. The modified approach is to convert the time-dependent problem to a static ..cap alpha../sup -/eigenvalue problem and regress ..cap alpha.. on solutions of a/sup -/ k/sup -/eigenvalue problem. In practice, this procedure is much more efficient than the direct calculation, and produces much more accurate results. Because the Monte Carlo codes are intrinsically three-dimensional and use elaborate continuous-energy cross sections, this technique is now used as a standard for evaluating other calculational techniques in odd geometries or with group cross sections.

Brockway, D.; Soran, P.; Whalen, P.

1985-01-01

401

Subwavelength hybrid terahertz waveguides.  

PubMed

We introduce and present general properties of hybrid terahertz waveguides. Weakly confined Zenneck waves on a metal-dielectric interface at terahertz frequencies can be transformed to a strongly confined yet low-loss subwavelength mode through coupling with a photonic mode of a nearby high-index dielectric strip. We analyze confinement, attenuation, and dispersion properties of this mode. The proposed design is suitable for planar integration and allows easy fabrication on chip scale. The superior waveguiding properties at terahertz frequencies could enable the hybrid terahertz waveguides as building blocks for terahertz integrated circuits. PMID:20052215

Nam, Sung Hyun; Taylor, Antoinette J; Efimov, Anatoly

2009-12-01

402

Real-time dynamics from imaginary-time quantum Monte Carlo simulations: Tests on oscillator chains  

SciTech Connect

We used methods of Bayesian statistical inference and the principle of maximum entropy to analytically continue imaginary-time Green{close_quote}s functions generated in quantum Monte Carlo simulations to obtain the real-time Green{close_quote}s functions. For test problems, we considered chains of harmonic and anharmonic oscillators whose properties we simulated by a hybrid path-integral quantum Monte Carlo method. From the imaginary-time displacement-displacement Green{close_quote}s function, we first obtained its spectral density. For harmonic oscillators, we demonstrated the peaks of this function were in the correct position and their areas satisfied a sum rule. Additionally, as a function of wave number, the peak positions followed the correct dispersion relation. For a double-well oscillator, we demonstrated that the peak location correctly predicted the tunnel splitting. Transforming the spectral densities to real-time Green{close_quote}s functions, we conclude that we can predict the real-time dynamics for length of times corresponding to five to ten times the natural period of the model. The length of time was limited by an overbroadening of the peaks in the spectral density caused by the simulation algorithm. {copyright} {ital 1996 The American Physical Society.}

Bonca, J.; Gubernatis, J.E. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1996-06-01

403

Development of robust hybrids for smart skin avionics  

Microsoft Academic Search

The author presents the conceptualization of robust hybrids which are conformally integrated onto aircraft structure for structural health monitoring applications. The robust hybrid concept exhibits high-performance signal processing and uses advanced hybrid packaging technologies to satisfy conformal integration requirements. The author also discusses the basic issues and requirements of smart skin avionics. The predominant issues of smart skin avionics integration

Terrance L. Thomas

1990-01-01

404

Monte Carlo alpha deposition  

SciTech Connect

Prior work demonstrated the importance of nuclear scattering to fusion product energy deposition in hot plasmas. This suggests careful examination of nuclear physics details in burning plasma simulations. An existing Monte Carlo fast ion transport code is being expanded to be a test bed for this examination. An initial extension, the energy deposition of fast alpha particles in a hot deuterium plasma, is reported. The deposition times and deposition ranges are modified by allowing nuclear scattering. Up to 10% of the initial alpha particle energy is carried to greater ranges and times by the more mobile recoil deuterons. 4 refs., 5 figs., 2 tabs.

Talley, T.L.; Evans, F.

1988-01-01

405

Monte Carlo fluorescence microtomography  

NASA Astrophysics Data System (ADS)

Fluorescence microscopy allows real-time monitoring of optical molecular probes for disease characterization, drug development, and tissue regeneration. However, when a biological sample is thicker than 1 mm, intense scattering of light would significantly degrade the spatial resolution of fluorescence microscopy. In this paper, we develop a fluorescence microtomography technique that utilizes the Monte Carlo method to image fluorescence reporters in thick biological samples. This approach is based on an l0-regularized tomography model and provides an excellent solution. Our studies on biomimetic tissue scaffolds have demonstrated that the proposed approach is capable of localizing and quantifying the distribution of optical molecular probe accurately and reliably.

Cong, Alexander X.; Hofmann, Matthias C.; Cong, Wenxiang; Xu, Yong; Wang, Ge

2011-07-01

406

Hybrid silicon evanescent devices  

Microsoft Academic Search

Si photonics as an integration platform has recently been a focus of optoelectronics research because of the promise of low-cost manufacturing based on the ubiquitous electronics fabrication infrastructure. The key challenge for Si photonic systems is the realization of compact, electrically driven optical gain elements. We review our recent developments in hybrid Si evanescent devices. We have demonstrated electrically pumped

Alexander W. Fang; Ying-hao Kuo; Richard Jones; Oded Cohen; Omri Raday; Matthew N. Sysak; Mario J. Paniccia; John E. Bowers

2007-01-01

407

Printed circuit card hybrid  

Microsoft Academic Search

A hybrid connector is presented whereby both electrical and fiber optic cables are connected to a printed circuit card. The connector consists of a female half which contains a plurality of fiber optic contact inserts molded into the connector, and also female electrical connections. The male half of the connector is an integral part of a printed circuit card constructed

Arnold Flores

1986-01-01

408

Hybrid FSAE Vehicle Realization.  

National Technical Information Service (NTIS)

The goal of this multi-year project is to create a fully functional University of Idaho entry in the hybrid FSAE competition. Vehicle integration is underway as part of a variety of 2010-11 senior design projects. This leverages a variety of analytical an...

E. Odom J. Law S. Beyerlein

2010-01-01

409

Quantum Monte Carlo study of porphyrin transition metal complexes  

NASA Astrophysics Data System (ADS)

Diffusion quantum Monte Carlo (DMC) calculations for transition metal (M) porphyrin complexes (MPo, M=Ni,Cu,Zn) are reported. We calculate the binding energies of the transition metal atoms to the porphin molecule. Our DMC results are in reasonable agreement with those obtained from density functional theory calculations using the B3LYP hybrid exchange-correlation functional. Our study shows that such calculations are feasible with the DMC method.

Koseki, Jun; Maezono, Ryo; Tachikawa, Masanori; Towler, M. D.; Needs, R. J.

2008-08-01

410

Coupled Electron-Ion Monte Carlo Calculations of Dense Metallic Hydrogen  

Microsoft Academic Search

We present an efficient new Monte Carlo method which couples path integrals for finite temperature protons with quantum Monte Carlo calculations for ground state electrons, and we apply it to metallic hydrogen for pressures beyond molecular dissociation. We report data for the equation of state for temperatures across the melting of the proton crystal. Our data exhibit more structure and

Carlo Pierleoni; David M. Ceperley; Markus Holzmann

2004-01-01

411

Clinical use of a commercial Monte Carlo treatment planning system for electron beams  

Microsoft Academic Search

In 2002 we fully implemented clinically a commercial Monte Carlo based treatment planning system for electron beams. The software, developed by MDS Nordion (presently Nucletron), is based on Kawrakow's VMC++ algorithm. The Monte Carlo module is integrated with our Theraplan Plus™ treatment planning system. An extensive commissioning process preceded clinical implementation of this software. Using a single virtual 'machine' for

J. E. Cygler; C. Lochrin; G. M. Daskalov; M. Howard; R. Zohr; B. Esche; L. Eapen; L. Grimard; J. M. Caudrelier

2005-01-01

412

Quasi-Monte Carlo Methods in Computer Graphics, Part II: The Radiance Equation  

Microsoft Academic Search

The radiance equation, which describes the global illumination problem in computer graphics, is a high dimensional integral equation. Estimates of the solu- tion are usually computed on the basis of Monte Carlo methods. In this paper we propose and investigate quasi-Monte Carlo methods, which means that we replace (pseudo-) random samples by low discrepancy sequences, yielding deterministic algorithms. We carry

Stefan Heinrich; Alexander Keller

1994-01-01

413

MCMini: Monte Carlo on GPGPU  

SciTech Connect

MCMini is a proof of concept that demonstrates the possibility for Monte Carlo neutron transport using OpenCL with a focus on performance. This implementation, written in C, shows that tracing particles and calculating reactions on a 3D mesh can be done in a highly scalable fashion. These results demonstrate a potential path forward for MCNP or other Monte Carlo codes.

Marcus, Ryan C. [Los Alamos National Laboratory

2012-07-25

414

Toward a Monte Carlo theory of quantum dynamics  

SciTech Connect

We consider in the present paper an extension of numerical path integral methods for use in computing finite temperature time correlation functions. We demonstrate that coordinate rotation techniques extend appreciably the time domain over which Monte Carlo methods are of use in the construction of such correlation functions.

Doll, J.D.; Coalson, R.D.; Freeman, D.L.

1987-08-01

415

Risk analysis by the guided monte carlo technique  

Microsoft Academic Search

Risk assessment of modeling predictions is becoming increasingly important as input to decision makers. Probabilistic risk analysis is typically expensive to perform since it generallyrequires the calculation of a model output Probability Distribution Function (PDF) followed by the integration of the risk portion of the PDF. Here we describe the new risk analysis Guided Monte Carlo (GMC) technique. It maintains

Jeffrey A. Shorter; Herschel A. Rabitz

1997-01-01

416

A Monte Carlo method for calculating orbits of comets  

Microsoft Academic Search

The present work is divided into two stages: 1. By using large numbers (several millions) of accurate orbit integrations with the K-S regularization, probability distributions for changes in the orbital elements of comets during encounters with planets are evaluated. 2. These distributions are used in a Monte Carlo simulation scheme which follows the evolution of orbits under repeated close encounters.

J. Q. Zheng; M. J. Valtonen; S. Mikkola; J. J. Matese; P. G. Whitman; H. Rickman

1994-01-01

417

Preparation of siloxane-silsesquioxane hybrid thin films for large-scale-integration interlayer dielectrics with excellent mechanical properties and low dielectric constants  

Microsoft Academic Search

Several kinds of homogeneous organic-inor- ganic hybrid polymer thin films were designed with im- proved mechanical properties and low dielectric constants (3.0). Novel soluble siloxane-silsesquioxane hybrid poly- mers were synthesized with cyclic and\\/or cage silane mono- mers, which had triorganosiloxy (R3Si1\\/2), diorganosiloxane (R2SiO2\\/2), and organosilsesquioxane (RSiO3\\/2) moieties with ethylene bridges at the molecular level, by the hydro- lysis and condensation

Jin-Heong Yim; Yi-Yeol Lyu; Hyun-Dam Jeong; Sang Kook Mah; Jingyu Hyeon-Lee; Jun-Hee Hahn; Gwang Seok Kim; Seok Chang; Jae-Geun Park

2003-01-01

418

A new method to assess Monte Carlo convergence  

SciTech Connect

The central limit theorem can be applied to a Monte Carlo solution if the following two requirements are satisfied: (1) the random variable has a finite mean and a finite variance; and (2) the number N of independent observations grows large. When these are satisfied, a confidence interval based on the normal distribution with a specified coverage probability can be formed. The first requirement is generally satisfied by the knowledge of the type of Monte Carlo tally being used. The Monte Carlo practitioner has only a limited number of marginally quantifiable methods that use sampled values to assess the fulfillment of the second requirement; e.g., statistical error reduction proportional to 1{radical}N with error magnitude guidelines. No consideration is given to what has not yet been sampled. A new method is presented here to assess the convergence of Monte Carlo solutions by analyzing the shape of the empirical probability density function (PDF) of history scores, f(x), where the random variable x is the score from one particle history and {integral}{sub {minus}{infinity}}{sup {infinity}} f(x) dx = 1. Since f(x) is seldom known explicitly, Monte Carlo particle random walks sample f(x) implicitly. Unless there is a largest possible history score, the empirical f(x) must eventually decrease more steeply than l/x{sup 3} for the second moment ({integral}{sub {minus}{infinity}}{sup {infinity}} x{sup 2}f(x) dx) to exist.

Forster, R.A.; Booth, T.E.; Pederson, S.P.

1993-05-01

419

Monte Carlo studies of field theory and quantum gravity  

NASA Astrophysics Data System (ADS)

In this dissertation I describe three main research projects in which I have participated as a graduate student. They share the common theme of using Monte Carlo computer simulation to investigate quantum field theories. I begin by giving a brief review of Monte Carlo simulation as a discrete path integral approach to a quantum theory. Two of the projects involve tests of the Monte Carlo renormalization group method, a systematic way of integrating out short distance features of a physical system in order to gain insight about its critical behavior, and hence its continuum limit. After a review of the ideas of the renormalization group, I discuss our thorough investigation of Monte Carlo renormalization of ?4 field theory on a two-dimensional square lattice. The second renormalization project overlaps with the other main thrust of my research, studying quantum gravity as the continuum limit of a sum over all possible ways of piecing together discrete simplices, or simplicial quantum gravity. I describe a unique Monte Carlo renormalization group study of scalar fields coupled to two-dimensional quantum gravity, where we were able to extract the anomalous field dimension for a case inaccessible to analytic methods. Finally I discuss a study of four-dimensional quantum gravity coupled to gauge fields and special concerns one must be aware of when measuring connected correlators in fluctuating geometry.

Gregory, Eric Brittain

420

MERADGEN: Monte Carlo generator for the simulation of radiative events in polarized Moller scattering  

SciTech Connect

The Monte Carlo generator MERADGEN for the simulation of QED radiative events in polarized Moller scattering has been developed. Analytical integration wherever it is possible provides rather fast generation. Some numerical tests and histograms are presented.

Andrei Afanasev; Eugene Chudakov; Alexander Ilyichev; Vladimir Zykunov

2006-04-04

421

Integrating Internet Video Conferencing Techniques and Online Delivery Systems with Hybrid Classes to Enhance Student Interaction and Learning in Accelerated Programs  

ERIC Educational Resources Information Center

Online course enrollment has increased dramatically over the past few years. The authors cite the reasons for this rapid growth and the opportunities open for enhancing teaching/learning techniques such as video conferencing and hybrid class combinations. The authors outlined an example of an accelerated learning, eight-class session course…

Beckwith, E. George; Cunniff, Daniel T.

2009-01-01

422

Monte-Carlo Simulation of SS433 X-ray Continuum  

NASA Astrophysics Data System (ADS)

Results of Monte-Carlo simulation of X-ray continuum of the galactic superaccreting microquasar SS433 are presented. We use observations of INTEGRAL in 2003 and INTEGRAL/RXTE in 2004. A model of the object, based on the observational data, was created, and Monte-Carlo simulation was used to obtain the model spectrum. Comparison with the experiment allowed us to infer physical parameters of SS433.

Krivosheyev, Yu. M.; Bisnovatyi-Kogan, G. S.; Cherepashchuk, A. M.; Postnov, K. A.

2009-12-01

423

Modelling cerebral blood oxygenation using Monte Carlo XYZ-PA  

NASA Astrophysics Data System (ADS)

Continuous monitoring of cerebral blood oxygenation is critically important for the management of many lifethreatening conditions. Non-invasive monitoring of cerebral blood oxygenation with a photoacoustic technique offers advantages over current invasive and non-invasive methods. We introduce a Monte Carlo XYZ-PA to model the energy deposition in 3D and the time-resolved pressures and velocity potential based on the energy absorbed by the biological tissue. This paper outlines the benefits of using Monte Carlo XYZ-PA for optimization of photoacoustic measurement and imaging. To the best of our knowledge this is the first fully integrated tool for photoacoustic modelling.

Zam, Azhar; Jacques, Steven L.; Alexandrov, Sergey; Li, Youzhi; Leahy, Martin J.

2013-02-01

424

Eulerian-Lagrangian relationships in Monte Carlo simulations of turbulent diffusion  

SciTech Connect

The results of this study show that Monte Carlo simulations of diffusion in homogeneous turbulence can be formulated in terms of the Eulerian space-time velocity autocorrelation function. Numerical results obtained using this approach agree with results obtained by Taylor (1921) using the Lagrangian autocorrelation function. Use was made of the equivalence of the Lagrangian and Eulerian Monte Carlo approaches to derive analytic relations between the Lagrangian integral time scale and the Eulerian integral space and time scales. These analytic results were verified by comparison to Monte Carlo simulations and to other theoretical results. They are in general agreement with many existing theories and semi-empirical relations.

Lee, J.T.; Stone, G.L.

1983-01-01

425

Hybrid Loofah  

Microsoft Academic Search

It is an old world genus, consisting of two cultivated and two wild species besides a wild new world species. Significant heterosis has also been reported in this genus and is being commercially exploited. It is an insect pollinated crop. Isolation is needed to prevent out crossing by insects when hybrid seed is produced by open pollination. Hybrid seed is

P. K. Singh; S. K. Dasgupta

2005-01-01

426

Hybrid Simulations.  

National Technical Information Service (NTIS)

The philosophy and numerical implementation of hybrid algorithms are reviewed. In the hybrid approximation, a plasma is described by a set of discrete equations, equivalent to a Vlasov-fluid system. The dynamics of one or more species are modeled using mo...

K. B. Quest

1987-01-01

427

Monte Carlo Hidden Markov Models.  

National Technical Information Service (NTIS)

We present a learning algorithm for hidden Markov models (HMM) with continuous state and observation spaces. All necessary probability density functions are approximated using samples, along with density trees generated from such samples. A Monte Carlo ve...

S. Thrun J. Langford

1998-01-01

428

Development and performance validation of an ISG diesel hybrid power-train for city transit buses - part I: Parameter matching and system integration  

Microsoft Academic Search

This two-part paper presents the development an ISG diesel hybrid power-train to provide a solution for the city transit buses. The ISG power-train which adopts the ISG parallel configuration which is inserted a thin but powerful motor between the engine and the flywheel is a compact and flexible power-train with high efficiency and sufficient power. The drive demand of Chinese

Xiaojian Mao; Hu Zhong; Guoqiang Ao; Junxi Wang; Hangbo Tang; Jing Feng; Bin Zhuo

2008-01-01

429

Research issues on stand-alone pv\\/hybrid systems: state-of-art and future technology perspectives for the integration of ?grid topologies on local island grids  

Microsoft Academic Search

A review of the state-of-art on stand-alone PV\\/hybrid is presented in this paper. Gathered data on operational experiences of autonomous power stations on Hellenic islands show that energy production costs using conventional power supply sources is high and PV systems is a sustainable solution for electrification of distant areas. Emphasis is put on muGrid systems as these topologies have certain

Christos Protogeropoulos; Stathis Tselepis; Aristomenis Neris

2006-01-01

430

Approximation, integration and differentiation of time functions using a set of orthogonal hybrid functions (HF) and their application to solution of first order differential equations  

Microsoft Academic Search

Differential equations of different types and orders are of utmost importance for mathematical modeling of control system problems. State variable method uses the concept of expressing n number of first order differential equations in vector matrix form to model and analyze\\/synthesize control systems.The present work proposes a new set of orthogonal hybrid functions (HF) which evolved from synthesis of sample-and-hold

Anish Deb; Gautam Sarkar; Anindita Ganguly; Amitava Biswas

431

Hybrid organic-inorganic optoelectronic subsystems on a chip  

Microsoft Academic Search

We report on hybrid organic-inorganic optoelectronic sysbsystems that integrate passive and active optical functions. The integration approaches involve various levels of hybridization, from splicing of pigtailed elements, to chip-to-chip attachment, to hybrid on-chip integration involving grafting and flip-chip mounting, and finally to true heteroepitaxy. The materials integrated include polymer, silica, silicon, silicon oxynitride, lithium niobate, indium phosphide, gallium arsenide, yttrium

Louay Eldada; Junichiro Fujita; Antonije Radojevic; Reinald Gerhardt; Tomoyuki Izuhara

2005-01-01

432

Low pressure semiconductor processing transport property modeling using direct simulation Monte Carlo  

Microsoft Academic Search

Summary form only given. In order to extend the capability of the Hybrid Plasma Equipment Model (HPEM)1 simulation code to increasingly lower operating pressure conditions, the direct simulation Monte Carlo (DSMC)2 method is used to improve the modeling of the heavy particle species in a hollow cathode magnetron (HCM) plasma reactor, a device used to implement the Ionized Metal Physical

Zheng Li; Hao Deng; D. A. Levin

2010-01-01

433

Multiscale Finite-Difference-Diffusion-Monte-Carlo Method for Simulating Dendritic Solidification  

Microsoft Academic Search

We present a novel hybrid computational method to simulate accurately dendritic solidification in the low undercooling limit where the dendrite tip radius is one or more orders of magnitude smaller than the characteristic spatial scale of variation of the surrounding thermal or solutal diffusion field. The first key feature of this method is an efficient multiscale diffusion Monte Carlo (DMC)

Mathis Plapp; Alain Karma

2000-01-01

434

Hybrid Warfare.  

National Technical Information Service (NTIS)

Senior military officials recently testified1 before Congress that current and future adversaries are likely to use 'hybrid warfare' tactics, a blending of conventional and irregular approaches across the full spectrum of conflict. In addition, several ac...

2010-01-01

435

Hybrid simulations  

SciTech Connect

The philosophy and numerical implementation of hybrid algorithms are reviewed. In the hybrid approximation, a plasma is described by a set of discrete equations, equivalent to a Vlasov-fluid system. The dynamics of one or more species are modeled using moment equations, while the remaining species are treated as a large number of individual macro-particles. In this paper the hybrid method will be compared to fluid and particle-in-cell algorithms, and the strengths and weaknesses of the various methods will be discussed. A specific limit of the hybrid model, that of macro-particle ions and massless, charge-neutralizing fluid electrons, will be analyzed in detail with particular emphasis on multi-dimensional codes.

Quest, K.B.

1987-01-01

436

Hybrid genes in the analysis of transformation conditions. 3. Temporal/spatial fate of NPTII gene integration, its inheritance and factors affecting these processes in Nicotiana plumbaginifolia.  

PubMed

Freshly isolated haploid mesophyll protoplasts of Nicotiana plumbaginifolia were transformed for kanamycin resistance. In 38% of the 224 transformants analysed, transmission of the NPTII gene occurred as a homozygous trait, while 62% of the transformants were heterozygous for the trait. In the first case, the foreign DNA integration predominantly (95%) resulted in monogenic inheritance. The second group was characterized by a significant (46%) proportion of multiple insertions. However, there was no clear-cut difference in the integration pattern between the two groups. Furthermore, transformation rates were increased by 4- to 10-fold when transformed diploid protoplasts were treated with UV light or with 3-aminobenzamide. The number of insertion sites was also increased by these treatments. These results shed further light on the fate of the foreign DNA in transformed plants and on means to control or manipulate the integration event(s). PMID:1966385

Gharti-Chhetri, G B; Cherdshewasart, W; Dewulf, J; Paszkowski, J; Jacobs, M; Negrutiu, I

1990-05-01

437

Nano-islands integrated evanescence-based lab-on-a-chip on silica-on-silicon and polydimethylsiloxane hybrid platform for detection of recombinant growth hormone.  

PubMed

Integration of nano-materials in optical microfluidic devices facilitates the realization of miniaturized analytical systems with enhanced sensing abilities for biological and chemical substances. In this work, a novel method of integration of gold nano-islands in a silica-on-silicon-polydimethylsiloxane microfluidic device is reported. The device works based on the nano-enhanced evanescence technique achieved by interacting the evanescent tail of propagating wave with the gold nano-islands integrated on the core of the waveguide resulting in the modification of the propagating UV-visible spectrum. The biosensing ability of the device is investigated by finite-difference time-domain simulation with a simplified model of the device. The performance of the proposed device is demonstrated for the detection of recombinant growth hormone based on antibody-antigen interaction. PMID:24106526

Ozhikandathil, J; Packirisamy, M

2012-10-09

438

Nano-islands integrated evanescence-based lab-on-a-chip on silica-on-silicon and polydimethylsiloxane hybrid platform for detection of recombinant growth hormone  

PubMed Central

Integration of nano-materials in optical microfluidic devices facilitates the realization of miniaturized analytical systems with enhanced sensing abilities for biological and chemical substances. In this work, a novel method of integration of gold nano-islands in a silica-on-silicon-polydimethylsiloxane microfluidic device is reported. The device works based on the nano-enhanced evanescence technique achieved by interacting the evanescent tail of propagating wave with the gold nano-islands integrated on the core of the waveguide resulting in the modification of the propagating UV-visible spectrum. The biosensing ability of the device is investigated by finite-difference time-domain simulation with a simplified model of the device. The performance of the proposed device is demonstrated for the detection of recombinant growth hormone based on antibody-antigen interaction.

Ozhikandathil, J.; Packirisamy, M.

2012-01-01

439

Integration of Monte Carlo simulations with PFGE experimental data yields constant RBE of 2.3 for DNA double-strand break induction by nitrogen ions between 125 and 225 keV/?m LET.  

PubMed

The number of small radiation-induced DNA fragments can be heavily underestimated when determined from measurements of DNA mass fractions by gel electrophoresis, leading to a consequent underestimation of the initial DNA damage induction. In this study we reanalyzed the experimental results for DNA fragmentation and DNA double-strand break (DSB) yields in human fibroblasts irradiated with ? rays and nitrogen ion beams with linear energy transfer (LET) equal to 80, 125, 175 and 225 keV/?m, originally measured by Höglund et al. (Radiat Res 155, 818-825, 2001 and Int J Radiat Biol 76, 539-547, 2000). In that study the authors converted the measured distributions of fragment masses into DNA fragment distributions using mid-range values of the measured fragment length intervals, in particular they assumed fragments with lengths in the interval of 0-48 kbp had the mid-range value of 24 kbp. However, our recent detailed simulations with the Monte Carlo code PARTRAC, while reasonably in agreement with the mass distributions, indicate significantly increased yields of very short fragments by high-LET radiation, so that the actual average fragment lengths, in the interval 0-48 kbp, 2.4 kbp for 225 keV/?m nitrogen ions were much shorter than the assumed mid-range value of 24 kbp. When the measured distributions of fragment masses are converted into fragment distributions using the average fragment lengths calculated by PARTRAC, significantly higher yields of DSB related to short fragments were obtained and resulted in a constant relative biological effectiveness (RBE) for DSB induction yield of 2.3 for nitrogen ions at 125-225 keV/?m LET. The previously reported downward trend of the RBE values over this LET range for DSB induction appears to be an artifact of an inadequate average fragment length in the smallest interval. PMID:23647004

Alloni, D; Campa, A; Friedland, W; Mariotti, L; Ottolenghi, A

2013-05-06

440

Hybrid dyadic-mixed-potential and combined spectral-space domain integral-equation analysis of quasi-3-D structures in stratified media  

Microsoft Academic Search

Planar circuits and antennas in stratified media are efficiently analyzed using an integral-equation formulation with a spectral-domain approach to construct the required Green's functions. This efficiency is largely lost when arbitrary three-dimensional (3-D) structures have to be analyzed. We, therefore, focus attention on \\

Mark Vrancken; Guy A. E. Vandenbosch

2003-01-01

441

Fluid-to-fluid spot-to-spreader (F2\\/S2) hybrid heat sink for integrated chip-level and hotspot-level thermal management  

Microsoft Academic Search

An innovative heat sink design aimed at meeting both the hotspot and large background heat flux requirements of next generation integrated circuits is presented. The heat sink design utilizes two separate, unmixed fluids to meet the cooling requirements of the chip with one fluid acting as a fluidic spreader dedicated to cooling the hotspots only, while the second fluid serves

Craig Green; Andrei G. Fedorov; Yogendra K. Joshi

2008-01-01

442

Hybrid genes in the analysis of transformation conditions. 3. Temporal\\/spatial fate of NPTII gene integration, its inheritance and factors affecting these processes in Nicotiana plumbaginifolia  

Microsoft Academic Search

Freshly isolated haploid mesophyll protoplasts of Nicotiana plumbaginifolia were transformed for kanamycin resistance. In 38% of the 224 transformants analysed, transmission of the NPTII gene occurred as a homozygous trait, while 62% of the transformants were heterozygous for the trait. In the first case, the foreign DNA integration predominantly (95%) resulted in monogenic inheritance. The second group was characterized by

G. B. Gharti-Chhetri; W. Cherdshewasart; J. Dewulf; J. Paszkowski; M. Jacobs; I. Negrutiu

1990-01-01

443

Monitoring Protein-Protein Interactions between the Mammalian Integral Membrane Transporters and PDZ-interacting Partners Using a Modified Split-ubiquitin Membrane Yeast Two-hybrid System*S?  

PubMed Central

PDZ-binding motifs are found in the C-terminal tails of numerous integral membrane proteins where they mediate specific protein-protein interactions by binding to PDZ-containing proteins. Conventional yeast two-hybrid screens have been used to probe protein-protein interactions of these soluble C termini. However, to date no in vivo technology has been available to study interactions between the full-length integral membrane proteins and their cognate PDZ-interacting partners. We previously developed a split-ubiquitin membrane yeast two-hybrid (MYTH) system to test interactions between such integral membrane proteins by using a transcriptional output based on cleavage of a transcription factor from the C terminus of membrane-inserted baits. Here we modified MYTH to permit detection of C-terminal PDZ domain interactions by redirecting the transcription factor moiety from the C to the N terminus of a given integral membrane protein thus liberating their native C termini. We successfully applied this “MYTH 2.0” system to five different mammalian full-length renal transporters and identified novel PDZ domain-containing partners of the phosphate (NaPi-IIa) and sulfate (NaS1) transporters that would have otherwise not been detectable. Furthermore this assay was applied to locate the PDZ-binding domain on the NaS1 protein. We showed that the PDZ-binding domain for PDZK1 on NaS1 is upstream of its C terminus, whereas the two interacting proteins, NHERF-1 and NHERF-2, bind at a location closer to the N terminus of NaS1. Moreover NHERF-1 and NHERF-2 increased functional sulfate uptake in Xenopus oocytes when co-expressed with NaS1. Finally we used MYTH 2.0 to demonstrate that the NaPi-IIa transporter homodimerizes via protein-protein interactions within the lipid bilayer. In summary, our study establishes the MYTH 2.0 system as a novel tool for interactive proteomics studies of membrane protein complexes.

Gisler, Serge M.; Kittanakom, Saranya; Fuster, Daniel; Wong, Victoria; Bertic, Mia; Radanovic, Tamara; Hall, Randy A.; Murer, Heini; Biber, Jurg; Markovich, Daniel; Moe, Orson W.; Stagljar, Igor

2008-01-01

444

Population size bias in diffusion Monte Carlo  

NASA Astrophysics Data System (ADS)

The size of the population of random walkers required to obtain converged estimates in diffusion Monte Carlo (DMC) increases dramatically with system size. We illustrate this by comparing ground state energies of small clusters of parahydrogen (up to 48 molecules) computed by DMC and path integral ground state (PIGS) techniques. We contend that the bias associated with a finite population of walkers is the most likely cause of quantitative numerical discrepancies between PIGS and DMC energy estimates reported in the literature, for this few-body Bose system. We discuss the viability of DMC as a general-purpose ground state technique, and argue that PIGS, and even finite temperature methods, enjoy more favorable scaling, and are therefore a superior option for systems of large size.

Boninsegni, Massimo; Moroni, Saverio

2012-11-01

445

A multiscale hybrid algorithm for fluctuating hydrodynamics  

NASA Astrophysics Data System (ADS)

We develop an algorithmic hybrid for simulating multiscale fluid flow with microscopic fluctuations. Random fluctuations occur in fluids at microscopic scales, and these microscopic fluctuations can lead to macroscopic system effects. For example, in the Rayleigh-Taylor problem, where a relatively heavy gas sits on top of a relatively light gas, spontaneous microscopic fluctuation at the interface of the gases leads to turbulent mixing. Given near-term computational power, the physical and temporal domain on which these systems can be studied using traditional particle simulations is extremely limited. Therefore, we seek algorithmic solutions to increase the effective computing power available to study such problems. We develop an explicit numerical solver for the Landau-Lifshitz Navier-Stokes (LLNS) equations, which incorporate thermal fluctuations into macroscopic hydrodynamics via stochastic; fluxes. A major goal is to correctly preserve the influence of the microscopic fluctuations on the behavior of the system. We show that several classical approaches fail to accurately reproduce fluctuations in energy or density, and we introduce a customized conservative centered scheme with a third-order Runge-Kutta temporal integrator that is specficially designed to produce correct fluctuations in all conserved quantities. We then use the adaptive mesh and algorithm refinement (AMAR) paradigm to create a multiscale hybrid method by coupling our LLNS solver with the direct simulation Monte Carlo (DSMC) particle method. We present numerical tests of systems in and out of equilibrium, including time-dependent systems, and demonstrate dynamic adaptive refinement. Mean system behavior and second moment statistics of our simulations match theoretical values and benchmarks well. We find that particular attention should be paid to the spectrum of the flux at the interface between the particle and continuum methods, specifically at non-hydrodynamic time scales. As an extension of the basic hybrid method, we consider the dynamics of a binary mixture of gases. Benchmark test problems, including a system under concentration gradient, match theory and molecular simulation well. We find that to study mixtures of gases with unequal masses, at equilibrium it may be reasonable to neglect the Soret effect; however, inclusion of the baro-diffusion effect is important.